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</div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Zakutayev%2C+A&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Zakutayev%2C+A&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Zakutayev%2C+A&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2502.08801">arXiv:2502.08801</a> <span> [<a href="https://arxiv.org/pdf/2502.08801">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> A Map of the Zintl AM2Pn2 Compounds: Influence of Chemistry on Stability and Electronic Structure </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Pike%2C+A">Andrew Pike</a>, <a href="/search/cond-mat?searchtype=author&query=Yuan%2C+Z">Zhenkun Yuan</a>, <a href="/search/cond-mat?searchtype=author&query=Kassa%2C+G">Gideon Kassa</a>, <a href="/search/cond-mat?searchtype=author&query=Hasan%2C+M+R">Muhammad R Hasan</a>, <a href="/search/cond-mat?searchtype=author&query=Goswami%2C+S">Smitakshi Goswami</a>, <a href="/search/cond-mat?searchtype=author&query=Dugu%2C+S">Sita Dugu</a>, <a href="/search/cond-mat?searchtype=author&query=Quadir%2C+S">Shaham Quadir</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S">Sage Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Kovnir%2C+K">Kirill Kovnir</a>, <a href="/search/cond-mat?searchtype=author&query=Liu%2C+J">Jifeng Liu</a>, <a href="/search/cond-mat?searchtype=author&query=Hautier%2C+G">Geoffroy Hautier</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2502.08801v1-abstract-short" style="display: inline;"> The AM2Pn2 (A= Ca, Sr, Ba, Yb, Mg; M= Mn, Zn, Cd, Mg; and Pn=N, P, As, Sb, Bi) family of Zintl phases has been known as thermoelectric materials and has recently gained much attention for highly promising materials for solar absorbers in single junction and tandem solar cells. In this paper we will, from first-principles, explore the entire family of AM2Pn2 compounds in terms of their ground state… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.08801v1-abstract-full').style.display = 'inline'; document.getElementById('2502.08801v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2502.08801v1-abstract-full" style="display: none;"> The AM2Pn2 (A= Ca, Sr, Ba, Yb, Mg; M= Mn, Zn, Cd, Mg; and Pn=N, P, As, Sb, Bi) family of Zintl phases has been known as thermoelectric materials and has recently gained much attention for highly promising materials for solar absorbers in single junction and tandem solar cells. In this paper we will, from first-principles, explore the entire family of AM2Pn2 compounds in terms of their ground state structure, thermodynamic stability, and electronic structure. We also perform photoluminescence spectroscopy on bulk powder and thin film samples to verify our results, including the first measurements of the bandgaps of SrCd2P2 and CaCd2P2. The AM2Pn2 compounds exhibit broad stability, are mostly isostructural in the CaAl2Si2-type structure (P3m1), and cover a wide range of bandgaps from 0 to beyond 3 eV. This could make them useful for a variety of purposes, for which we propose several candidates, such as CaZn2N2 for tandem top cell solar absorbers and SrCd2Sb2 and CaZn2Sb2 for infrared detectors. By examining the band structures of the AM2Pn2, we find that Mg3Sb2 has the most promise as a thermoelectric material due to several off-螕 valence band pockets which are unique to it among the compositions studied here. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2502.08801v1-abstract-full').style.display = 'none'; document.getElementById('2502.08801v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 February, 2025; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2025. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">46 pages, 12 figures, submitted to Chemistry of Materials</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2412.02600">arXiv:2412.02600</a> <span> [<a href="https://arxiv.org/pdf/2412.02600">pdf</a>, <a href="https://arxiv.org/format/2412.02600">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Ion exchange synthesizes layered polymorphs of MgZrN$_2$ and MgHfN$_2$, two metastable semiconductors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Rom%2C+C+L">Christopher L. Rom</a>, <a href="/search/cond-mat?searchtype=author&query=Jankousky%2C+M">Matthew Jankousky</a>, <a href="/search/cond-mat?searchtype=author&query=Phan%2C+M+Q">Maxwell Q. Phan</a>, <a href="/search/cond-mat?searchtype=author&query=O%27Donnell%2C+S">Shaun O'Donnell</a>, <a href="/search/cond-mat?searchtype=author&query=Regier%2C+C">Corlyn Regier</a>, <a href="/search/cond-mat?searchtype=author&query=Neilson%2C+J+R">James R. Neilson</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovic%2C+V">Vladan Stevanovic</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2412.02600v1-abstract-short" style="display: inline;"> The synthesis of ternary nitrides is uniquely difficult, in large part because elemental N$_2$ is relatively inert. However, lithium reacts readily with other metals and N$_2$, making Li-M-N the most numerous sub-set of ternary nitrides. Here, we use Li$_2$ZrN$_2$, a ternary with a simple synthesis recipe, as a precursor for ion exchange reactions towards AZrN$_2$ (A = Mg, Fe, Cu, Zn). In situ syn… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.02600v1-abstract-full').style.display = 'inline'; document.getElementById('2412.02600v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2412.02600v1-abstract-full" style="display: none;"> The synthesis of ternary nitrides is uniquely difficult, in large part because elemental N$_2$ is relatively inert. However, lithium reacts readily with other metals and N$_2$, making Li-M-N the most numerous sub-set of ternary nitrides. Here, we use Li$_2$ZrN$_2$, a ternary with a simple synthesis recipe, as a precursor for ion exchange reactions towards AZrN$_2$ (A = Mg, Fe, Cu, Zn). In situ synchrotron powder X-ray diffraction studies show that Li$^+$ and Mg$^{2+}$ undergo ion exchange topochemically, preserving the layers of octahedral [ZrN$_6$] to yield a metastable layered polymorph of MgZrN$_2$ (spacegroup $R\overline{3}m$) rather than the calculated ground state structure ($I41/amd$). UV-vis measurements show an optical absorption onset near 2.0 eV, consistent with the calculated bandgap for this polymorph. Our experimental attempts to extend this ion exchange method towards FeZrN$_2$, CuZrN$_2$, and ZnZrN$_2$ resulted in decomposition products (A + ZrN + 1/6 N$_2$), an outcome that our computational results explain via the higher metastability of these phases. We successfully extended this ion exchange method to other Li-M-N precursors by synthesizing MgHfN$_2$ from Li$_2$HfN$_2$. In addition to the discovery of metastable $R\overline{3}m$ MgZrN$_2$ and MgHfN$_2$, this work highlights the potential of the 63 unique Li-M-N phases as precursors to synthesize new ternary nitrides. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2412.02600v1-abstract-full').style.display = 'none'; document.getElementById('2412.02600v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 December, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.14037">arXiv:2407.14037</a> <span> [<a href="https://arxiv.org/pdf/2407.14037">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Low Leakage Ferroelectric Heteroepitaxial Al$_{0.7}$Sc$_{0.3}$N Films on GaN </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Yazawa%2C+K">Keisuke Yazawa</a>, <a href="/search/cond-mat?searchtype=author&query=Evans%2C+C">Charles Evans</a>, <a href="/search/cond-mat?searchtype=author&query=Dickey%2C+E">Elizabeth Dickey</a>, <a href="/search/cond-mat?searchtype=author&query=Tellekamp%2C+B">Brooks Tellekamp</a>, <a href="/search/cond-mat?searchtype=author&query=Brennecka%2C+G+L">Geoff L. Brennecka</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2407.14037v1-abstract-short" style="display: inline;"> Wurtzite (Al,Sc)N ferroelectrics are attractive for microelectronics applications due to their chemical and epitaxial structural compatibility with wurtzite semiconductors such as GaN and (Al,Ga)N. However, the leakage current in epitaxial stacks reported to date should be reduced for reliable device operation. Following the tradition of other semiconductor heterostructures, crystalline structural… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.14037v1-abstract-full').style.display = 'inline'; document.getElementById('2407.14037v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.14037v1-abstract-full" style="display: none;"> Wurtzite (Al,Sc)N ferroelectrics are attractive for microelectronics applications due to their chemical and epitaxial structural compatibility with wurtzite semiconductors such as GaN and (Al,Ga)N. However, the leakage current in epitaxial stacks reported to date should be reduced for reliable device operation. Following the tradition of other semiconductor heterostructures, crystalline structural quality, as measured by breadth of diffraction peaks and correlating with dislocation density, is commonly used as a proxy for leakage current, but we demonstrate here that the crystalline mosaicity that dominates the broadening of diffraction peaks in epitaxial Al$_{0.7}$Sc$_{0.3}$N stacks does not dominate leakage current. We report here well-saturated ferroelectric hysteresis loops and orders of magnitude lower leakage current (0.07 A cm$^{-2}$) compared to values reported in literature (1 ~ 19 A cm$^{-2}$) for sputter-deposited epitaxial Al$_{0.7}$Sc$_{0.3}$N/GaN of comparable crystalline quality to prior reports. Further, we show Al$_{0.7}$Sc$_{0.3}$N on lattice-matched InGaN buffers with improved structural characteristics exhibits increased leakage characteristics. This demonstration and understanding can help to guide further efforts towards reliable wurtzite ferroelectric devices and prioritize approaches targeting further leakage current reduction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.14037v1-abstract-full').style.display = 'none'; document.getElementById('2407.14037v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 4 figures, 1 table</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.17492">arXiv:2406.17492</a> <span> [<a href="https://arxiv.org/pdf/2406.17492">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Synthesis pathways to thin films of stable layered nitrides </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Jankousky%2C+M">Matthew Jankousky</a>, <a href="/search/cond-mat?searchtype=author&query=Wolf%2C+L">Laszlo Wolf</a>, <a href="/search/cond-mat?searchtype=author&query=Feng%2C+Y">Yi Feng</a>, <a href="/search/cond-mat?searchtype=author&query=Rom%2C+C+L">Christopher L. Rom</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S+R">Sage R. Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Borkiewicz%2C+O">Olaf Borkiewicz</a>, <a href="/search/cond-mat?searchtype=author&query=LaVan%2C+D+A">David A. LaVan</a>, <a href="/search/cond-mat?searchtype=author&query=Smaha%2C+R+W">Rebecca W. Smaha</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovic%2C+V">Vladan Stevanovic</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.17492v2-abstract-short" style="display: inline;"> Controlled synthesis of metastable materials away from equilibrium is of interest in materials chemistry. Thin film deposition methods with rapid condensation of vapor precursors can readily synthesize metastable phases, but often struggle to yield the thermodynamic ground state. Growing thermodynamically-stable structures using kinetically-limited synthesis methods in important for practical appl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.17492v2-abstract-full').style.display = 'inline'; document.getElementById('2406.17492v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.17492v2-abstract-full" style="display: none;"> Controlled synthesis of metastable materials away from equilibrium is of interest in materials chemistry. Thin film deposition methods with rapid condensation of vapor precursors can readily synthesize metastable phases, but often struggle to yield the thermodynamic ground state. Growing thermodynamically-stable structures using kinetically-limited synthesis methods in important for practical applications in electronics and energy conversion. Here, we reveal a synthesis pathway to thermodynamically-stable ordered layered ternary nitride materials, and discuss why disordered metastable intermediate phases tend to form. We show that starting from elemental vapor precursors leads to a 3D long-range disordered MgMoN2 thin film metastable intermediate structure, with a layered short-range order that has a low-energy transformation barrier to the layered 2D-like stable structure. This synthesis approach is extended to ScTaN2, MgWN2 and MgTa2N3, and may lead to the synthesis of other layered nitride thin films with unique semiconducting and quantum properties. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.17492v2-abstract-full').style.display = 'none'; document.getElementById('2406.17492v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 25 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.16224">arXiv:2406.16224</a> <span> [<a href="https://arxiv.org/pdf/2406.16224">pdf</a>, <a href="https://arxiv.org/format/2406.16224">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Artificial Intelligence">cs.AI</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1039/D4DD00143E">10.1039/D4DD00143E <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> From Text to Test: AI-Generated Control Software for Materials Science Instruments </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=F%C3%A9bba%2C+D+M">Davi M F茅bba</a>, <a href="/search/cond-mat?searchtype=author&query=Egbo%2C+K">Kingsley Egbo</a>, <a href="/search/cond-mat?searchtype=author&query=Callahan%2C+W+A">William A. Callahan</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.16224v2-abstract-short" style="display: inline;"> Large language models (LLMs) are transforming the landscape of chemistry and materials science. Recent examples of LLM-accelerated experimental research include virtual assistants for parsing synthesis recipes from the literature, or using the extracted knowledge to guide synthesis and characterization. Despite these advancements, their application is constrained to labs with automated instruments… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.16224v2-abstract-full').style.display = 'inline'; document.getElementById('2406.16224v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.16224v2-abstract-full" style="display: none;"> Large language models (LLMs) are transforming the landscape of chemistry and materials science. Recent examples of LLM-accelerated experimental research include virtual assistants for parsing synthesis recipes from the literature, or using the extracted knowledge to guide synthesis and characterization. Despite these advancements, their application is constrained to labs with automated instruments and control software, leaving much of materials science reliant on manual processes. Here, we demonstrate the rapid deployment of a Python-based control module for a Keithley 2400 electrical source measure unit using ChatGPT-4. Through iterative refinement, we achieved effective instrument management with minimal human intervention. Additionally, a user-friendly graphical user interface (GUI) was created, effectively linking all instrument controls to interactive screen elements. Finally, we integrated this AI-crafted instrument control software with a high-performance stochastic optimization algorithm to facilitate rapid and automated extraction of electronic device parameters related to semiconductor charge transport mechanisms from current-voltage (IV) measurement data. This integration resulted in a comprehensive open-source toolkit for semiconductor device characterization and analysis using IV curve measurements. We demonstrate the application of these tools by acquiring, analyzing, and parameterizing IV data from a Pt/Cr$_2$O$_3$:Mg/$尾$-Ga$_2$O$_3$ heterojunction diode, a novel stack for high-power and high-temperature electronic devices. This approach underscores the powerful synergy between LLMs and the development of instruments for scientific inquiry, showcasing a path for further acceleration in materials science. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.16224v2-abstract-full').style.display = 'none'; document.getElementById('2406.16224v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.15637">arXiv:2406.15637</a> <span> [<a href="https://arxiv.org/pdf/2406.15637">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Low-Temperature Synthesis of Stable CaZn$_2$P$_2$ Zintl Phosphide Thin Films as Candidate Top Absorbers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Quadir%2C+S">Shaham Quadir</a>, <a href="/search/cond-mat?searchtype=author&query=Yuan%2C+Z">Zhenkun Yuan</a>, <a href="/search/cond-mat?searchtype=author&query=Esparza%2C+G">Guillermo Esparza</a>, <a href="/search/cond-mat?searchtype=author&query=Dugu%2C+S">Sita Dugu</a>, <a href="/search/cond-mat?searchtype=author&query=Mangum%2C+J">John Mangum</a>, <a href="/search/cond-mat?searchtype=author&query=Pike%2C+A">Andrew Pike</a>, <a href="/search/cond-mat?searchtype=author&query=Hasan%2C+M+R">Muhammad Rubaiat Hasan</a>, <a href="/search/cond-mat?searchtype=author&query=Kassa%2C+G">Gideon Kassa</a>, <a href="/search/cond-mat?searchtype=author&query=Wang%2C+X">Xiaoxin Wang</a>, <a href="/search/cond-mat?searchtype=author&query=Coban%2C+Y">Yagmur Coban</a>, <a href="/search/cond-mat?searchtype=author&query=Liu%2C+J">Jifeng Liu</a>, <a href="/search/cond-mat?searchtype=author&query=Kovnir%2C+K">Kirill Kovnir</a>, <a href="/search/cond-mat?searchtype=author&query=Fenning%2C+D+P">David P. Fenning</a>, <a href="/search/cond-mat?searchtype=author&query=Reid%2C+O+G">Obadiah G. Reid</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Hautier%2C+G">Geoffroy Hautier</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S+R">Sage R. Bauers</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.15637v1-abstract-short" style="display: inline;"> The development of tandem photovoltaics and photoelectrochemical solar cells requires new absorber materials with band gaps in the range of ~1.5-2.3 eV, for use in the top cell paired with a narrower-gap bottom cell. An outstanding challenge is finding materials with suitable optoelectronic and defect properties, good operational stability, and synthesis conditions that preserve underlying device… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.15637v1-abstract-full').style.display = 'inline'; document.getElementById('2406.15637v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.15637v1-abstract-full" style="display: none;"> The development of tandem photovoltaics and photoelectrochemical solar cells requires new absorber materials with band gaps in the range of ~1.5-2.3 eV, for use in the top cell paired with a narrower-gap bottom cell. An outstanding challenge is finding materials with suitable optoelectronic and defect properties, good operational stability, and synthesis conditions that preserve underlying device layers. This study demonstrates the Zintl phosphide compound CaZn$_2$P$_2$ as a compelling candidate semiconductor for these applications. We prepare phase pure, 500 nm-thick CaZn$_2$P$_2$ thin films using a scalable reactive sputter deposition process at growth temperatures as low as 100 掳C, which is desirable for device integration. UV-vis spectroscopy shows that CaZn$_2$P$_2$ films exhibit an optical absorptivity of ~10$^4$ cm$^-$$^1$ at ~1.95 eV direct band gap. Room-temperature photoluminescence (PL) measurements show near-band-edge optical emission, and time-resolved microwave conductivity (TRMC) measurements indicate a photoexcited carrier lifetime of ~30 ns. CaZn$_2$P$_2$ is highly stable in both ambient conditions and moisture, as evidenced by PL and TRMC measurements. Experimental data are supported by first-principles calculations, which indicate the absence of low-formation-energy, deep intrinsic defects. Overall, our study should motivate future work integrating this potential top cell absorber material into tandem solar cells. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.15637v1-abstract-full').style.display = 'none'; document.getElementById('2406.15637v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.06060">arXiv:2405.06060</a> <span> [<a href="https://arxiv.org/pdf/2405.06060">pdf</a>, <a href="https://arxiv.org/format/2405.06060">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/5.0219503">10.1063/5.0219503 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> GdWN$_3$ is a Nitride Perovskite </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Smaha%2C+R+W">Rebecca W. Smaha</a>, <a href="/search/cond-mat?searchtype=author&query=Mangum%2C+J+S">John S. Mangum</a>, <a href="/search/cond-mat?searchtype=author&query=Yadav%2C+N">Neha Yadav</a>, <a href="/search/cond-mat?searchtype=author&query=Rom%2C+C+L">Christopher L. Rom</a>, <a href="/search/cond-mat?searchtype=author&query=Wieliczka%2C+B+M">Brian M. Wieliczka</a>, <a href="/search/cond-mat?searchtype=author&query=Julien%2C+B">Baptiste Julien</a>, <a href="/search/cond-mat?searchtype=author&query=Treglia%2C+A">Andrew Treglia</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+C+L">Craig L. Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Gorai%2C+P">Prashun Gorai</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S+R">Sage R. Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.06060v1-abstract-short" style="display: inline;"> Nitride perovskites $AB$N$_3$ are an emerging and highly under-explored class of materials that are of interest due to their intriguing calculated ferroelectric, optoelectronic, and other functional properties. Incorporating novel $A$-site cations is one strategy to tune and expand such properties; for example, Gd$^{3+}$ is compelling due to its large magnetic moment, potentially leading to multif… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.06060v1-abstract-full').style.display = 'inline'; document.getElementById('2405.06060v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.06060v1-abstract-full" style="display: none;"> Nitride perovskites $AB$N$_3$ are an emerging and highly under-explored class of materials that are of interest due to their intriguing calculated ferroelectric, optoelectronic, and other functional properties. Incorporating novel $A$-site cations is one strategy to tune and expand such properties; for example, Gd$^{3+}$ is compelling due to its large magnetic moment, potentially leading to multiferroic behavior. However, the theoretically predicted ground state of GdWN$_3$ is a non-perovskite monoclinic structure. Here, we experimentally show that GdWN$_3$ crystallizes in a perovskite structure. High-throughput combinatorial sputtering with activated nitrogen is employed to synthesize thin films of Gd$_{1-x}$W$_{x}$N$_{3-y}$ with low oxygen content within the bulk of the films. Ex-situ annealing crystallizes a polycrystalline perovskite phase in a narrow composition window near $x=1$. LeBail fits of synchrotron grazing incidence wide angle X-ray scattering data are consistent with a perovskite ground-state structure. New density functional theory calculations that included antiferromagnetic configurations confirm that the ground-state structure of GdWN$_3$ is a distorted $Pnma$ perovskite with antiferromagnetic ordering, in contrast to prior predictions. Initial property measurements find that GdWN$_3$ is paramagnetic down to $T=2$ K with antiferromagnetic correlations and that the absorption onset depends on cation stoichiometry. This work provides an important stepping stone towards the rapid expansion of the emerging family of nitride perovskites and towards our understanding of their potential multiferroic properties. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.06060v1-abstract-full').style.display = 'none'; document.getElementById('2405.06060v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Applied Physics Letters 125, 112902 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.07166">arXiv:2401.07166</a> <span> [<a href="https://arxiv.org/pdf/2401.07166">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Reliable operation of Cr$_2$O$_3$:Mg/ $尾$-Ga$_2$O$_3$ p-n heterojunction diodes at 600$^\circ$C </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Callahan%2C+W+A">William A. Callahan</a>, <a href="/search/cond-mat?searchtype=author&query=Egbo%2C+K">Kingsley Egbo</a>, <a href="/search/cond-mat?searchtype=author&query=Lee%2C+C">Cheng-Wei Lee</a>, <a href="/search/cond-mat?searchtype=author&query=Ginley%2C+D">David Ginley</a>, <a href="/search/cond-mat?searchtype=author&query=O%27Hayre%2C+R">Ryan O'Hayre</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.07166v1-abstract-short" style="display: inline;"> $尾$-Ga$_2$O$_3… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.07166v1-abstract-full').style.display = 'inline'; document.getElementById('2401.07166v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.07166v1-abstract-full" style="display: none;"> $尾$-Ga$_2$O$_3$-based semiconductor heterojunctions have recently demonstrated improved performance at high voltages and elevated temperatures and are thus promising for applications in power electronic devices and harsh-environment sensors. However, the long-term reliability of these ultra-wide band gap (UWBG) semiconductor devices remains barely addressed and may be strongly influenced by chemical reactions at the p-n heterojunction interface. Here, we experimentally demonstrate operation and evaluate the reliability of Cr$_2$O$_3$:Mg/ $尾$-Ga$_2$O$_3$ p-n heterojunction diodes at during extended operation at 600$^\circ$C, as well as after 30 repeated cycles between 25-550$^\circ$C. The calculated pO2-temperature phase stability diagram of the Ga-Cr-O material system predicts that Ga$_2$O$_3$ and Cr$_2$O$_3$ should remain thermodynamically stable in contact with each other over a wide range of oxygen pressures and operating temperatures. The fabricated Cr$_2$O$_3$:Mg / $尾$-Ga$_2$O$_3$ p-n heterojunction diodes show room-temperature on/off ratios >10$^4$ at $\pm$5V and a breakdown voltage (V$_{Br}$) of -390V. The leakage current increases with increasing temperature up to 600$^\circ$C, which is attributed to Poole-Frenkel emission with a trap barrier height of 0.19 eV. Over the course of a 140-hour thermal soak at 600$^\circ$C, both the device turn-on voltage and on-state resistance increase from 1.08V and 5.34 m$惟$-cm$^2$ to 1.59V and 7.1 m$惟$-cm$^2$ respectively. This increase is attributed to the accumulation of Mg and MgO at the Cr$_2$O$_3$/Ga$_2$O$_3$ interface as observed from TOF-SIMS analysis. These findings inform future design strategies of UWBG semiconductor devices for harsh environment operation and underscore the need for further reliability assessments for $尾$-Ga$_2$O$_3$ based devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.07166v1-abstract-full').style.display = 'none'; document.getElementById('2401.07166v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 4 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.06924">arXiv:2401.06924</a> <span> [<a href="https://arxiv.org/pdf/2401.06924">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> NiGa$_{2}$O$_{4}$ interfacial layers in NiO/Ga$_{2}$O$_{3}$ heterojunction diodes at high temperature </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Egbo%2C+K">Kingsley Egbo</a>, <a href="/search/cond-mat?searchtype=author&query=Garrity%2C+E+M">Emily M. Garrity</a>, <a href="/search/cond-mat?searchtype=author&query=Callahan%2C+W+A">William A. Callahan</a>, <a href="/search/cond-mat?searchtype=author&query=Chae%2C+C">Chris Chae</a>, <a href="/search/cond-mat?searchtype=author&query=Lee%2C+C">Cheng-Wei Lee</a>, <a href="/search/cond-mat?searchtype=author&query=Tellekamp%2C+B">Brooks Tellekamp</a>, <a href="/search/cond-mat?searchtype=author&query=Hwang%2C+J">Jinwoo Hwang</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovic%2C+V">Vladan Stevanovic</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.06924v1-abstract-short" style="display: inline;"> NiO/Ga$_{2}$O$_{3}$ heterojunction diodes have attracted attention for high-power applications, but their high-temperature performance and reliability remain underexplored. Here we report on the time evolution of the static electrical properties in the widely studied p-NiO/n-Ga$_{2}$O$_{3}$heterojunction diodes and the formation of NiGa$_{2}$O$_{4}$ interfacial layers when operated at… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.06924v1-abstract-full').style.display = 'inline'; document.getElementById('2401.06924v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.06924v1-abstract-full" style="display: none;"> NiO/Ga$_{2}$O$_{3}$ heterojunction diodes have attracted attention for high-power applications, but their high-temperature performance and reliability remain underexplored. Here we report on the time evolution of the static electrical properties in the widely studied p-NiO/n-Ga$_{2}$O$_{3}$heterojunction diodes and the formation of NiGa$_{2}$O$_{4}$ interfacial layers when operated at $550^{\circ}$C. Results of our thermal cycling experiment show an initial leakage current increase which stabilizes after sustained thermal load, due to reactions at the NiO-Ga$_{2}$O$_{3}$ interface. High-resolution TEM microstructure analysis of the devices after thermal cycling indicates that the NiO-Ga$_{2}$O$_{3}$ interface forms ternary compounds at high temperatures, and thermodynamic calculations suggest the formation of the spinel NiGa$_{2}$O$_{4}$ layer between NiO and Ga$_{2}$O$_{3}$. First-principles defect calculations find that NiGa$_{2}$O$_{4}$ shows low p-type intrinsic doping, and hence can also serve to limit electric field crowding at the interface. Vertical NiO/Ga$_{2}$O$_{3}$ diodes with intentionally grown 5 nm thin spinel-type NiGa$_{2}$O$_{4}$ interfacial layers show excellent device ON/OFF ratio of > 10$^{10}$($\pm$3 V), V$_{ON}$ of ~1.9 V, and breakdown voltage of ~ 1.2 kV for an initial unoptimized 300-micron diameter device. These p-n heterojunction diodes are promising for high-voltage, high-temperature applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.06924v1-abstract-full').style.display = 'none'; document.getElementById('2401.06924v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 5 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.06606">arXiv:2401.06606</a> <span> [<a href="https://arxiv.org/pdf/2401.06606">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Rapid screening of molecular beam epitaxy conditions for monoclinic (InxGa1-x)2O3 alloys </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Schaefer%2C+S">Stephen Schaefer</a>, <a href="/search/cond-mat?searchtype=author&query=Febba%2C+D">Davi Febba</a>, <a href="/search/cond-mat?searchtype=author&query=Egbo%2C+K">Kingsley Egbo</a>, <a href="/search/cond-mat?searchtype=author&query=Teeter%2C+G">Glenn Teeter</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Tellekamp%2C+B">Brooks Tellekamp</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.06606v1-abstract-short" style="display: inline;"> Molecular beam epitaxy is one of the highest quality growth methods, capable of achieving theoretical material property limits and unprecedented device performance. However, such ultimate quality usually comes at the cost of painstaking optimization of synthesis conditions and slow experimental iteration rates. Here we report on high-throughput molecular beam epitaxy with rapid screening of synthe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.06606v1-abstract-full').style.display = 'inline'; document.getElementById('2401.06606v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.06606v1-abstract-full" style="display: none;"> Molecular beam epitaxy is one of the highest quality growth methods, capable of achieving theoretical material property limits and unprecedented device performance. However, such ultimate quality usually comes at the cost of painstaking optimization of synthesis conditions and slow experimental iteration rates. Here we report on high-throughput molecular beam epitaxy with rapid screening of synthesis conditions using a novel cyclical growth and in-situ etch method. This novel approach leverages sub-oxide desorption present during molecular beam epitaxy and as such should be broadly applicable to other material systems. As a proof of concept, this method is applied to rapidly investigate the growth space for the ternary alloy (InxGa1-x)2O3 on (010) oriented beta-Ga2O3 substrates using in-situ reflection high energy electron diffraction measurements. Two distinct growth regimes are identified and analyzed using machine learning image recognition algorithms, the first stabilizing a streaky 2x surface reconstruction typical of In-catalyzed beta-Ga2O3 growth, and the second exhibiting a spotty/faceted pattern typical of phase separation. Targeted growth of (InxGa1-x)2O3 is performed under conditions near the boundary of the two regimes resulting in a 980 nm thick epitaxial layer with In mole fraction up to 5.6%. The cyclical growth/etch method retains the ~1 nm surface roughness of the single crystal substrate, increases experimental throughput approximately 6x, and improves single crystal substrate utilization by >40x. The high-throughput MBE method enables rapid discovery of growth regimes for ultra-wide bandgap oxide alloys for power conversion devices operating with high efficiency at high voltages and temperatures, as well as optical devices such as ultraviolet photodetectors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.06606v1-abstract-full').style.display = 'none'; document.getElementById('2401.06606v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">14 pages, 8 figures, submitted to Journal of Materials Chemistry A on November 22, 2023</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> NREL/JA-5K00-88113 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.01964">arXiv:2401.01964</a> <span> [<a href="https://arxiv.org/pdf/2401.01964">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1039/D4SC00322E">10.1039/D4SC00322E <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Bulk synthesis of Zn$_3$WN$_4$ via solid-state metathesis </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Rom%2C+C+L">Christopher L. Rom</a>, <a href="/search/cond-mat?searchtype=author&query=O%27Donnell%2C+S">Shaun O'Donnell</a>, <a href="/search/cond-mat?searchtype=author&query=Huang%2C+K">Kayla Huang</a>, <a href="/search/cond-mat?searchtype=author&query=Klein%2C+R+A">Ryan A. Klein</a>, <a href="/search/cond-mat?searchtype=author&query=Kramer%2C+M+J">Morgan J. Kramer</a>, <a href="/search/cond-mat?searchtype=author&query=Smaha%2C+R+W">Rebecca W. Smaha</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.01964v2-abstract-short" style="display: inline;"> Ternary nitrides are of growing technological importance, with applications as semiconductors, catalysts, and magnetic materials; however, new synthetic tools are needed to advance materials discovery efforts. Here, we show that Zn$_3$WN$_4$ can be synthesized via metathesis reactions between Li$_6$WN$_4$ and Zn$X_2$ ($X$ = Br, Cl, F). In situ synchrotron powder X-ray diffraction and differential… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.01964v2-abstract-full').style.display = 'inline'; document.getElementById('2401.01964v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.01964v2-abstract-full" style="display: none;"> Ternary nitrides are of growing technological importance, with applications as semiconductors, catalysts, and magnetic materials; however, new synthetic tools are needed to advance materials discovery efforts. Here, we show that Zn$_3$WN$_4$ can be synthesized via metathesis reactions between Li$_6$WN$_4$ and Zn$X_2$ ($X$ = Br, Cl, F). In situ synchrotron powder X-ray diffraction and differential scanning calorimetry show that the reaction onset is correlated with the Zn$X_2$ melting point and that product purity is inversely correlated with the reaction's exothermicity. High resolution synchrotron powder X-ray diffraction measurements show that this bulk synthesis produces a structure with substantial cation ordering, as opposed to the disordered structure initially discovered via thin film sputtering. Diffuse reflectance spectroscopy reveals that Zn$_3$WN$_4$ powders exhibit two optical absorption onsets at 2.5 eV and 4.0 eV, indicating wide-bandgap semiconducting behavior and suggesting a small amount of structural disorder. We hypothesize that this synthesis strategy is generalizable because many potential Li-$M$-N precursors (where $M$ is a metal) are available for synthesizing new ternary nitride materials. This work introduces a promising synthesis strategy that will accelerate the discovery of novel functional ternary nitrides and other currently inaccessible materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.01964v2-abstract-full').style.display = 'none'; document.getElementById('2401.01964v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 5 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Chem. Sci. 2024 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.11749">arXiv:2312.11749</a> <span> [<a href="https://arxiv.org/pdf/2312.11749">pdf</a>, <a href="https://arxiv.org/format/2312.11749">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Computational insights into phase equilibria between wide-gap semiconductors and contact materials </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lee%2C+C">Cheng-Wei Lee</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovi%C4%87%2C+V">Vladan Stevanovi膰</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2312.11749v1-abstract-short" style="display: inline;"> Novel wide-band-gap semiconductors are needed for next-generation power electronic but there is a gap between a promising material and a functional device. Finding stable contacts is one of the major challenges, which is currently dealt with mainly via trial and error. Herein, we computationally investigate the thermochemistry and phase co-existence at the junction between three wide gap semicondu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.11749v1-abstract-full').style.display = 'inline'; document.getElementById('2312.11749v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.11749v1-abstract-full" style="display: none;"> Novel wide-band-gap semiconductors are needed for next-generation power electronic but there is a gap between a promising material and a functional device. Finding stable contacts is one of the major challenges, which is currently dealt with mainly via trial and error. Herein, we computationally investigate the thermochemistry and phase co-existence at the junction between three wide gap semiconductors, $尾$-Ga$_{2}$O$_{3}$, GeO$_2$, and GaN, and possible contact materials. The pool of possible contacts includes 47 elemental metals and 4 common $n$-type transparent conducting oxides (ZnO, TiO$_2$, SnO$_2$, and In$_2$O$_3$). We use first-principles thermodynamics to model the Gibbs free energies of chemical reactions as a function of the gas pressure (p$_{\mathrm{O}_2}$/p$_{\mathrm{N}_2}$) and equilibrium temperature. We deduce whether a semiconductor/contact interface will be stable at relevant conditions, possibly influencing the long-term reliability and performance of devices. We generally find that most elemental metals tend to oxidize or nitridize and form various interface oxide/nitride layers. Exceptions include select late- and post-transition metals, and in case of GaN also the alkali metals, which are predicted to exhibit stable coexistence, although in many cases at relatively low gas partial pressures. Similar is true for the transparent conducting oxides, for which in most cases we predict a preference toward forming ternary oxides when in contact with $尾$-Ga$_{2}$O$_{3}$ and GeO$_{2}$. The only exception is SnO$_2$, which can form stable contacts with both oxides. Finally, we show how the same approach can be used to predict gas partial pressure vs. temperature phase diagrams to help direct synthesis of ternary compounds. We believe these results provide a valuable guidance in selecting contact materials to wide-gap semiconductors and suitable growth conditions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.11749v1-abstract-full').style.display = 'none'; document.getElementById('2312.11749v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.19502">arXiv:2310.19502</a> <span> [<a href="https://arxiv.org/pdf/2310.19502">pdf</a>, <a href="https://arxiv.org/format/2310.19502">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Mechanistically-guided materials chemistry: synthesis of new ternary nitrides, CaZrN$_2$ and CaHfN$_2$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Rom%2C+C+L">Christopher L. Rom</a>, <a href="/search/cond-mat?searchtype=author&query=Novick%2C+A">Andrew Novick</a>, <a href="/search/cond-mat?searchtype=author&query=McDermott%2C+M+J">Matthew J. McDermott</a>, <a href="/search/cond-mat?searchtype=author&query=Yakovenko%2C+A+A">Andrey A. Yakovenko</a>, <a href="/search/cond-mat?searchtype=author&query=Gallawa%2C+J+R">Jessica R. Gallawa</a>, <a href="/search/cond-mat?searchtype=author&query=Tran%2C+G+T">Gia Thinh Tran</a>, <a href="/search/cond-mat?searchtype=author&query=Asebiah%2C+D+C">Dominic C. Asebiah</a>, <a href="/search/cond-mat?searchtype=author&query=Storck%2C+E+N">Emily N. Storck</a>, <a href="/search/cond-mat?searchtype=author&query=McBride%2C+B+C">Brennan C. McBride</a>, <a href="/search/cond-mat?searchtype=author&query=Miller%2C+R+C">Rebecca C. Miller</a>, <a href="/search/cond-mat?searchtype=author&query=Prieto%2C+A+L">Amy L. Prieto</a>, <a href="/search/cond-mat?searchtype=author&query=Persson%2C+K+A">Kristin A. Persson</a>, <a href="/search/cond-mat?searchtype=author&query=Toberer%2C+E">Eric Toberer</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovi%C4%87%2C+V">Vladan Stevanovi膰</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Neilson%2C+J+R">James R. Neilson</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.19502v1-abstract-short" style="display: inline;"> Recent computational studies have predicted many new ternary nitrides, revealing synthetic opportunities in this underexplored phase space. However, synthesizing new ternary nitrides is difficult, in part because intermediate and product phases often have high cohesive energies that inhibit diffusion. Here, we report the synthesis of two new phases, calcium zirconium nitride (CaZrN$_2$) and calciu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.19502v1-abstract-full').style.display = 'inline'; document.getElementById('2310.19502v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.19502v1-abstract-full" style="display: none;"> Recent computational studies have predicted many new ternary nitrides, revealing synthetic opportunities in this underexplored phase space. However, synthesizing new ternary nitrides is difficult, in part because intermediate and product phases often have high cohesive energies that inhibit diffusion. Here, we report the synthesis of two new phases, calcium zirconium nitride (CaZrN$_2$) and calcium hafnium nitride (CaHfN$_2$), by solid state metathesis reactions between Ca$_3$N$_2$ and $M$Cl$_4$ ($M$ = Zr, Hf). Although the reaction nominally proceeds to the target phases in a 1:1 ratio of the precursors via Ca$_3$N$_2$ + $M$Cl$_4$ $\rightarrow$ Ca$M$N$_2$ + 2 CaCl$_2$, reactions prepared this way result in Ca-poor materials (Ca$_xM_{2-x}$N$_2$, $x<1$). A small excess of Ca$_3$N$_2$ (ca. 20 mol\%) is needed to yield stoichiometric Ca$M$N$_2$, as confirmed by high-resolution synchrotron powder X-ray diffraction. In situ synchrotron X-ray diffraction studies reveal that nominally stoichiometric reactions produce Zr$^{3+}$ intermediates early in the reaction pathway, and the excess Ca$_3$N$_2$ is needed to reoxidize Zr$^{3+}$ intermediates back to the Zr$^{4+}$ oxidation state of CaZrN$_2$. Analysis of computationally-derived chemical potential diagrams rationalizes this synthetic approach and its contrast from the synthesis of MgZrN$_2$. These findings additionally highlight the utility of in situ diffraction studies and computational thermochemistry to provide mechanistic guidance for synthesis. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.19502v1-abstract-full').style.display = 'none'; document.getElementById('2310.19502v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.18188">arXiv:2310.18188</a> <span> [<a href="https://arxiv.org/pdf/2310.18188">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1016/j.joule.2024.02.017">10.1016/j.joule.2024.02.017 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Discovery of the Zintl-phosphide BaCd$_{2}$P$_{2}$ as a long carrier lifetime and stable solar absorber </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Yuan%2C+Z">Zhenkun Yuan</a>, <a href="/search/cond-mat?searchtype=author&query=Dahliah%2C+D">Diana Dahliah</a>, <a href="/search/cond-mat?searchtype=author&query=Hasan%2C+M+R">Muhammad Rubaiat Hasan</a>, <a href="/search/cond-mat?searchtype=author&query=Kassa%2C+G">Gideon Kassa</a>, <a href="/search/cond-mat?searchtype=author&query=Pike%2C+A">Andrew Pike</a>, <a href="/search/cond-mat?searchtype=author&query=Quadir%2C+S">Shaham Quadir</a>, <a href="/search/cond-mat?searchtype=author&query=Claes%2C+R">Romain Claes</a>, <a href="/search/cond-mat?searchtype=author&query=Chandler%2C+C">Cierra Chandler</a>, <a href="/search/cond-mat?searchtype=author&query=Xiong%2C+Y">Yihuang Xiong</a>, <a href="/search/cond-mat?searchtype=author&query=Kyveryga%2C+V">Victoria Kyveryga</a>, <a href="/search/cond-mat?searchtype=author&query=Yox%2C+P">Philip Yox</a>, <a href="/search/cond-mat?searchtype=author&query=Rignanese%2C+G">Gian-Marco Rignanese</a>, <a href="/search/cond-mat?searchtype=author&query=Dabo%2C+I">Ismaila Dabo</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Fenning%2C+D+P">David P. Fenning</a>, <a href="/search/cond-mat?searchtype=author&query=Reid%2C+O+G">Obadiah G. Reid</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S">Sage Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Liu%2C+J">Jifeng Liu</a>, <a href="/search/cond-mat?searchtype=author&query=Kovnir%2C+K">Kirill Kovnir</a>, <a href="/search/cond-mat?searchtype=author&query=Hautier%2C+G">Geoffroy Hautier</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2310.18188v1-abstract-short" style="display: inline;"> Thin-film photovoltaics offers a path to significantly decarbonize our energy production. Unfortunately, current materials commercialized or under development as thin-film solar cell absorbers are far from optimal as they show either low power conversion efficiency or issues with earth-abundance and stability. Entirely new and disruptive materials platforms are rarely discovered as the search for… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.18188v1-abstract-full').style.display = 'inline'; document.getElementById('2310.18188v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.18188v1-abstract-full" style="display: none;"> Thin-film photovoltaics offers a path to significantly decarbonize our energy production. Unfortunately, current materials commercialized or under development as thin-film solar cell absorbers are far from optimal as they show either low power conversion efficiency or issues with earth-abundance and stability. Entirely new and disruptive materials platforms are rarely discovered as the search for new solar absorbers is traditionally slow and serendipitous. Here, we use first principles high-throughput screening to accelerate this process. We identify new solar absorbers among known inorganic compounds using considerations on band gap, carrier transport, optical absorption but also on intrinsic defects which can strongly limit the carrier lifetime and ultimately the solar cell efficiency. Screening about 40,000 materials, we discover the Zintl-phosphide BaCd$_{2}$P$_{2}$ as a potential high-efficiency solar absorber. Follow-up experimental work confirms the predicted promises of BaCd$_{2}$P$_{2}$ highlighting an optimal band gap for visible absorption, bright photoluminescence, and long carrier lifetime of up to 30 ns even for unoptimized powder samples. Importantly, BaCd$_{2}$P$_{2}$ does not contain any critical elements and is highly stable in air and water. Our work opens an avenue for a new family of stable, earth-abundant, high-performance Zintl-based solar absorbers. It also demonstrates how recent advances in first principles computation can accelerate the search of photovoltaic materials by combining high-throughput screening with experiment. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.18188v1-abstract-full').style.display = 'none'; document.getElementById('2310.18188v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Joule 8 (2024) 1412-1429 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.02233">arXiv:2306.02233</a> <span> [<a href="https://arxiv.org/pdf/2306.02233">pdf</a>, <a href="https://arxiv.org/format/2306.02233">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1039/D3TC02059B">10.1039/D3TC02059B <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Bulk and film synthesis pathways to ternary magnesium tungsten nitrides </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Rom%2C+C+L">Christopher L. Rom</a>, <a href="/search/cond-mat?searchtype=author&query=Smaha%2C+R+W">Rebecca W. Smaha</a>, <a href="/search/cond-mat?searchtype=author&query=Knebel%2C+C+A">Callan A. Knebel</a>, <a href="/search/cond-mat?searchtype=author&query=Heinselman%2C+K+N">Karen N. Heinselman</a>, <a href="/search/cond-mat?searchtype=author&query=Neilson%2C+J+R">James R. Neilson</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S+R">Sage R. Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.02233v1-abstract-short" style="display: inline;"> Bulk solid state synthesis of nitride materials usually leads to thermodynamically stable, cation-ordered crystal structures, whereas thin film synthesis tends to favor disordered, metastable phases. This dichotomy is inconvenient both for basic materials discovery, where non-equilibrium thin film synthesis methods can be useful to overcome reaction kinetic barriers, and for practical technology a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.02233v1-abstract-full').style.display = 'inline'; document.getElementById('2306.02233v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.02233v1-abstract-full" style="display: none;"> Bulk solid state synthesis of nitride materials usually leads to thermodynamically stable, cation-ordered crystal structures, whereas thin film synthesis tends to favor disordered, metastable phases. This dichotomy is inconvenient both for basic materials discovery, where non-equilibrium thin film synthesis methods can be useful to overcome reaction kinetic barriers, and for practical technology applications where stable ground state structures are sometimes required. Here, we explore the uncharted Mg-W-N chemical phase space, using rapid thermal annealing to reconcile the differences between thin film and bulk powder syntheses. Combinatorial co-sputtering synthesis from Mg and W targets in a N$_2$ environment yielded cation-disordered Mg-W-N phases in the rocksalt (0.1< Mg/(Mg+W) <0.9), and hexagonal boron nitride (0.7< Mg/(Mg+W) <0.9) structure types. In contrast, bulk synthesis produced a cation-ordered polymorph of MgWN$_2$ that consists of alternating layers of rocksalt-like [MgN$_6$] octahedra and nickeline-like [WN$_6$] trigonal prisms (denoted "rocksaline"). Thermodynamic calculations corroborate these observations, showing rocksaline MgWN$_2$ is stable while other polymorphs are metastable. We also show that rapid thermal annealing can convert disordered rocksalt films to this cation-ordered polymorph near the MgWN$_2$ stoichiometry. Electronic structure calculations suggest that this rocksalt-to-rocksaline structural transformation should also drive a metallic-to-semiconductor transformation. In addition to revealing three new phases (rocksalt MgWN$_2$ and Mg$_3$WN$_4$, hexagonal boron nitride Mg$_3$WN$_4$, and rocksaline MgWN$_2$), these findings highlight how rapid thermal annealing can control polymorphic transformations, adding a new strategy for exploration of thermodynamic stability in uncharted phase spaces. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.02233v1-abstract-full').style.display = 'none'; document.getElementById('2306.02233v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.00098">arXiv:2305.00098</a> <span> [<a href="https://arxiv.org/pdf/2305.00098">pdf</a>, <a href="https://arxiv.org/format/2305.00098">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevMaterials.7.084411">10.1103/PhysRevMaterials.7.084411 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Structural and Optoelectronic Properties of Thin Film LaWN$_3$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Smaha%2C+R+W">Rebecca W. Smaha</a>, <a href="/search/cond-mat?searchtype=author&query=Mangum%2C+J+S">John S. Mangum</a>, <a href="/search/cond-mat?searchtype=author&query=Leahy%2C+I+A">Ian A. Leahy</a>, <a href="/search/cond-mat?searchtype=author&query=Calder%2C+J">Julian Calder</a>, <a href="/search/cond-mat?searchtype=author&query=Hautzinger%2C+M+P">Matthew P. Hautzinger</a>, <a href="/search/cond-mat?searchtype=author&query=Muzzillo%2C+C+P">Christopher P. Muzzillo</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+C+L">Craig L. Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Talley%2C+K+R">Kevin R. Talley</a>, <a href="/search/cond-mat?searchtype=author&query=Eley%2C+S">Serena Eley</a>, <a href="/search/cond-mat?searchtype=author&query=Gorai%2C+P">Prashun Gorai</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S+R">Sage R. Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.00098v1-abstract-short" style="display: inline;"> Nitride perovskites are an emerging class of materials that have been predicted to display a range of interesting physics and functional properties, but they are under-explored due to the difficulty of synthesizing oxygen-free nitrides. LaWN3, recently reported as the first oxygen-free nitride perovskite, exhibited polar symmetry and a large piezoelectric coefficient. However, the predicted ferroe… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.00098v1-abstract-full').style.display = 'inline'; document.getElementById('2305.00098v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.00098v1-abstract-full" style="display: none;"> Nitride perovskites are an emerging class of materials that have been predicted to display a range of interesting physics and functional properties, but they are under-explored due to the difficulty of synthesizing oxygen-free nitrides. LaWN3, recently reported as the first oxygen-free nitride perovskite, exhibited polar symmetry and a large piezoelectric coefficient. However, the predicted ferroelectric switching was hindered by large leakage current, which motivates better understanding of its electronic structure and optical properties. Here, we study the structure and optoelectronic properties of thin film LaWN3 in greater detail, employing combinatorial techniques to correlate these properties with cation stoichiometry. We report a two-step synthesis that utilizes a more common RF substrate bias instead of a nitrogen plasma source, yielding nanocrystalline films that are crystallized by ex-situ annealing. We investigate the structure and composition of these films, finding polycrystalline La-rich and highly textured W-rich films. The optical absorption onset and temperature- and magnetic field-dependent resistivity are consistent with semiconducting behavior and are highly sensitive to cation stoichiometry, which may be related to amorphous impurities: metallic W or WNx in W-rich samples and insulating La2O3 in La-rich samples. The fractional magnetoresistance is linear and small, consistent with defect scattering, and a W-rich sample has n-type carriers with high densities and low mobilities. We demonstrate a photoresponse in LaWN3: the resistivity of a La-rich sample is enhanced by 28% at low temperature, likely due to a defect trapping mechanism. The physical properties of LaWN3 are highly sensitive to cation stoichiometry, like many oxide perovskites, which therefore calls for precise composition control to utilize the interesting properties observed in this nitride perovskite. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.00098v1-abstract-full').style.display = 'none'; document.getElementById('2305.00098v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Materials 7, 084411 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2304.02161">arXiv:2304.02161</a> <span> [<a href="https://arxiv.org/pdf/2304.02161">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Ultrathin Stable Ohmic Contacts for High-Temperature Operation of $尾$-Ga$_2$O$_3$ Devices </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Callahan%2C+W+A">William A. Callahan</a>, <a href="/search/cond-mat?searchtype=author&query=Supple%2C+E">Edwin Supple</a>, <a href="/search/cond-mat?searchtype=author&query=Ginley%2C+D">David Ginley</a>, <a href="/search/cond-mat?searchtype=author&query=Sanders%2C+M">Michael Sanders</a>, <a href="/search/cond-mat?searchtype=author&query=Gorman%2C+B+P">Brian P. Gorman</a>, <a href="/search/cond-mat?searchtype=author&query=O%27Hayre%2C+R">Ryan O'Hayre</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2304.02161v1-abstract-short" style="display: inline;"> Beta gallium oxide ($尾$-Ga$_2$O$_3$) shows significant promise in the high-temperature, high-power, and sensing electronics applications. However, long-term stable metallization layers for Ohmic contacts at high temperature present unique thermodynamic challenges. The current most common Ohmic contact design based on 20 nm of Ti has been repeatedly demonstrated to fail at even moderately elevated… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.02161v1-abstract-full').style.display = 'inline'; document.getElementById('2304.02161v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2304.02161v1-abstract-full" style="display: none;"> Beta gallium oxide ($尾$-Ga$_2$O$_3$) shows significant promise in the high-temperature, high-power, and sensing electronics applications. However, long-term stable metallization layers for Ohmic contacts at high temperature present unique thermodynamic challenges. The current most common Ohmic contact design based on 20 nm of Ti has been repeatedly demonstrated to fail at even moderately elevated temperatures (300-400$^{\circ}$C) due to a combination of non-stoichiometric Ti/Ga$_2$O$_3$ interfacial reactions and kinetically favored Ti diffusion processes. Here we demonstrate stable Ohmic contacts for Ga$_2$O$_3$ devices operating up to 500-600$^{\circ}$C using ultrathin Ti layers with a self-limiting interfacial reaction. The ultrathin Ti layer in the 5nm Ti / 100nm Au contact stack is designed to fully oxidize while forming an Ohmic contact, thereby limiting both thermodynamic and kinetic instability. This novel contact design strategy results in an epitaxial conductive anatase titanium oxide interface layer that enables low-resistance Ohmic contacts that are stable both under long-term continuous operation (>500 hours) at 600$^{\circ}$C in vacuum ($\leq$ 10$^{-4}$ Torr), as well as after repeated thermal cycling (15 times) between room temperature and 550$^{\circ}$C in flowing N$_2$. This stable Ohmic contact design will accelerate the development of high-temperature devices by enabling research focus to shift towards rectifying contacts and other interfacial layers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2304.02161v1-abstract-full').style.display = 'none'; document.getElementById('2304.02161v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 April, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">25 Pages, 7 Figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.06103">arXiv:2303.06103</a> <span> [<a href="https://arxiv.org/pdf/2303.06103">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Anomalously Abrupt Switching of Ferroelectric Wurtzites </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Yazawa%2C+K">Keisuke Yazawa</a>, <a href="/search/cond-mat?searchtype=author&query=Hayden%2C+J">John Hayden</a>, <a href="/search/cond-mat?searchtype=author&query=Maria%2C+J">Jon-Paul Maria</a>, <a href="/search/cond-mat?searchtype=author&query=Zhu%2C+W">Wanlin Zhu</a>, <a href="/search/cond-mat?searchtype=author&query=Trolier-McKinstry%2C+S">Susan Trolier-McKinstry</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Brennecka%2C+G+L">Geoff L. Brennecka</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2303.06103v1-abstract-short" style="display: inline;"> Ferroelectric polarization switching is one common example of a process that occurs via nucleation and growth, and understanding switching kinetics is crucial for applications such as ferroelectric memory. Here we describe and interpret anomalous switching dynamics in the wurtzite nitride thin film ferroelectrics Al0.7Sc0.3N and Al0.94B0.06N using a general model that can be directly applied to ot… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.06103v1-abstract-full').style.display = 'inline'; document.getElementById('2303.06103v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.06103v1-abstract-full" style="display: none;"> Ferroelectric polarization switching is one common example of a process that occurs via nucleation and growth, and understanding switching kinetics is crucial for applications such as ferroelectric memory. Here we describe and interpret anomalous switching dynamics in the wurtzite nitride thin film ferroelectrics Al0.7Sc0.3N and Al0.94B0.06N using a general model that can be directly applied to other abrupt transitions that proceed via nucleation and growth. When substantial growth and impingement occur while nucleation rate is increasing, such as in these wurtzite ferroelectrics under high electric fields, abrupt polarization reversal leads to very large Avrami coefficients (e.g., n = 11), inspiring an extension of the KAI (Kolmogorov-Avrami-Ishibashi) model. We apply this extended model to two related but distinct scenarios that crossover between (typical) behavior described by sequential nucleation and growth and a more abrupt transition arising from significant growth prior to peak nucleation rate. This work therefore provides more complete description of general nucleation and growth kinetics applicable to any system while specifically addressing both the anomalously abrupt polarization reversal behavior in new wurtzite ferroelectrics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.06103v1-abstract-full').style.display = 'none'; document.getElementById('2303.06103v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2210.16686">arXiv:2210.16686</a> <span> [<a href="https://arxiv.org/pdf/2210.16686">pdf</a>, <a href="https://arxiv.org/format/2210.16686">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Is Cu$_{3-x}$P a semiconductor, a metal, or a semimetal? </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Crovetto%2C+A">Andrea Crovetto</a>, <a href="/search/cond-mat?searchtype=author&query=Unold%2C+T">Thomas Unold</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2210.16686v1-abstract-short" style="display: inline;"> Despite the recent surge in interest in Cu$_{3-x}$P for catalysis, batteries, and plasmonics, the electronic nature of Cu$_{3-x}$P remains unclear. Some studies have shown evidence of semiconducting behavior, whereas others have argued that Cu$_{3-x}$P is a metallic compound. Here, we attempt to resolve this dilemma on the basis of combinatorial thin-film experiments, electronic structure calculat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.16686v1-abstract-full').style.display = 'inline'; document.getElementById('2210.16686v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.16686v1-abstract-full" style="display: none;"> Despite the recent surge in interest in Cu$_{3-x}$P for catalysis, batteries, and plasmonics, the electronic nature of Cu$_{3-x}$P remains unclear. Some studies have shown evidence of semiconducting behavior, whereas others have argued that Cu$_{3-x}$P is a metallic compound. Here, we attempt to resolve this dilemma on the basis of combinatorial thin-film experiments, electronic structure calculations, and semiclassical Boltzmann transport theory. We find strong evidence that stoichiometric, defect-free Cu$_3$P is an intrinsic semimetal, i.e., a material with a small overlap between the valence and the conduction band. On the other hand, experimentally realizable Cu$_{3-x}$P films are always p-type semimetals natively doped by copper vacancies regardless of $x$. It is not implausible that Cu$_{3-x}$P samples with very small characteristic sizes (such as small nanoparticles) are semiconductors due to quantum confinement effects that result in opening of a band gap. We observe high hole mobilities (276 cm$^2$/Vs) in Cu$_{3-x}$P films at low temperatures, pointing to low ionized impurity scattering rates in spite of a high doping density. We report an optical effect equivalent to the Burstein-Moss shift, and we assign an infrared absorption peak to bulk interband transitions rather than to a surface plasmon resonance. From a materials processing perspective, this study demonstrates the suitability of reactive sputter deposition for detailed high-throughput studies of emerging metal phosphides. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.16686v1-abstract-full').style.display = 'none'; document.getElementById('2210.16686v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2205.02424">arXiv:2205.02424</a> <span> [<a href="https://arxiv.org/pdf/2205.02424">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/5.0098979">10.1063/5.0098979 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Landau-Devonshire Analysis of Strain Effects on Ferroelectric Al1-xScxN </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Yazawa%2C+K">Keisuke Yazawa</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Brennecka%2C+G+L">Geoff L. Brennecka</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2205.02424v1-abstract-short" style="display: inline;"> We present a thermodynamic analysis of the recently discovered nitride ferroelectric materials using the classic Landau-Devonshire approach. The electrostrictive and dielectric stiffness coefficients of Al1-xScxN with wurtzite structure (6mm) are determined using a free energy density function assuming a hexagonal parent phase (6/mmm), with the first order phase transition based on the dielectric… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.02424v1-abstract-full').style.display = 'inline'; document.getElementById('2205.02424v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2205.02424v1-abstract-full" style="display: none;"> We present a thermodynamic analysis of the recently discovered nitride ferroelectric materials using the classic Landau-Devonshire approach. The electrostrictive and dielectric stiffness coefficients of Al1-xScxN with wurtzite structure (6mm) are determined using a free energy density function assuming a hexagonal parent phase (6/mmm), with the first order phase transition based on the dielectric stiffness relationships. The results of this analysis show that the strain sensitivity of the energy barrier is one order of magnitude larger than that of the spontaneous polarization in these novel wurtzite ferroelectrics, yet both are less sensitive to strain compared to classic perovskite ferroelectrics. These analysis results reported here explain experimentally reported sensitivity of coercive field to elastic strain/stress in Al1-xScxN films, and would enable further thermodynamic analysis via phase field simulation and related methods. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.02424v1-abstract-full').style.display = 'none'; document.getElementById('2205.02424v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2205.01913">arXiv:2205.01913</a> <span> [<a href="https://arxiv.org/pdf/2205.01913">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Ionic Bonds Control Ferroelectric Behavior in Wurtzite Nitrides </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Yazawa%2C+K">Keisuke Yazawa</a>, <a href="/search/cond-mat?searchtype=author&query=Mangum%2C+J">John Mangum</a>, <a href="/search/cond-mat?searchtype=author&query=Gorai%2C+P">Prashun Gorai</a>, <a href="/search/cond-mat?searchtype=author&query=Brennecka%2C+G+L">Geoff L. Brennecka</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2205.01913v1-abstract-short" style="display: inline;"> Ferroelectricity enables key integrated technologies from non-volatile memory to precision ultrasound. Wurtzite ferroelectric Al1-xScxN has recently attracted attention because of its robust ferroelectricity and Si process compatibility in addition to being the first known ferroelectric wurtzite. However, the origin and control of ferroelectricity in wurtzite materials is not yet fully understood.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.01913v1-abstract-full').style.display = 'inline'; document.getElementById('2205.01913v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2205.01913v1-abstract-full" style="display: none;"> Ferroelectricity enables key integrated technologies from non-volatile memory to precision ultrasound. Wurtzite ferroelectric Al1-xScxN has recently attracted attention because of its robust ferroelectricity and Si process compatibility in addition to being the first known ferroelectric wurtzite. However, the origin and control of ferroelectricity in wurtzite materials is not yet fully understood. Here we show that the local bond ionicity, rather than simply the change in tetrahedral distortion, is key to controlling the macroscopic ferroelectric response, according to our coupled experimental and computational results. Across the composition gradient in Sc < 0.35 range and 140-260 nm thickness in combinatorial thin films of Al1-xScxN, the pure wurtzite phase exhibits a similar c/a ratio regardless of the Sc content, due to elastic interaction with neighboring crystals. The coercive field and spontaneous polarization significantly decrease with increasing Sc content despite this invariant c/a ratio, due to the more ionic bonding nature of Sc-N relative to the more covalent Al-N bonds, supported by DFT calculations. Based on these insights, ionicity engineering is introduced as an approach to reduce coercive field of Al1-xScxN for memory and other applications and to control ferroelectric properties in other wurtzites. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2205.01913v1-abstract-full').style.display = 'none'; document.getElementById('2205.01913v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 May, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.09158">arXiv:2204.09158</a> <span> [<a href="https://arxiv.org/pdf/2204.09158">pdf</a>, <a href="https://arxiv.org/ps/2204.09158">ps</a>, <a href="https://arxiv.org/format/2204.09158">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Ternary Wide Band Gap Oxides for High-Power Electronics Identified Computationally </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Garrity%2C+E+M">Emily McDonald Garrity</a>, <a href="/search/cond-mat?searchtype=author&query=Lee%2C+C">Cheng-Wei Lee</a>, <a href="/search/cond-mat?searchtype=author&query=Gorai%2C+P">Prashun Gorai</a>, <a href="/search/cond-mat?searchtype=author&query=Tellekamp%2C+B">Brooks Tellekamp</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovi%C4%87%2C+V">Vladan Stevanovi膰</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2204.09158v1-abstract-short" style="display: inline;"> As electricity grids become more renewable energy-compliant, there will be a need for novel semiconductors that can withstand high power, high voltage, and high temperatures. Wide band gap (WBG) semiconductors tend to exhibit large breakdown field, allowing high operating voltages. Currently explored WBG materials for power electronics are costly (GaN), difficult to synthesize as high-quality sing… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.09158v1-abstract-full').style.display = 'inline'; document.getElementById('2204.09158v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.09158v1-abstract-full" style="display: none;"> As electricity grids become more renewable energy-compliant, there will be a need for novel semiconductors that can withstand high power, high voltage, and high temperatures. Wide band gap (WBG) semiconductors tend to exhibit large breakdown field, allowing high operating voltages. Currently explored WBG materials for power electronics are costly (GaN), difficult to synthesize as high-quality single crystals (SiC) and at scale (diamond, BN), have low thermal conductivity ($尾$-Ga$_2$O$_3$), or cannot be suitably doped (AlN). We conduct a computational search for novel semiconductors across 1,340 known metal-oxides using first-principles calculations and existing transport models. We calculate the Baliga figure of merit (BFOM) and lattice thermal conductivity ($魏_L$) to identify top candidates for n-type power electronics. We find 40 mostly ternary oxides that have higher $魏_L$ than $尾$-Ga$_2$O$_3$ and higher n-type BFOM than SiC and GaN. Among these, several material classes emerge, including 2-2-7 stoichiometry thortveitites and pyrochlores, II-IV spinels, and calcite-type borates. Within these classes, we propose In$_2$Ge$_2$O$_7$, Mg$_2$GeO$_4$, and InBO$_3$ as they are the most favorable for n-type doping based on our preliminary evaluation and could be grown as single crystals or thin film heterostructures. These materials could help advance power electronic devices for the future grid. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.09158v1-abstract-full').style.display = 'none'; document.getElementById('2204.09158v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 8 figures, submitted to and in-review at Physical Review X Energy</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.00112">arXiv:2204.00112</a> <span> [<a href="https://arxiv.org/pdf/2204.00112">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Systems and Control">eess.SY</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Gallium Oxide Heterojunction Diodes for Improved High-Temperature Performance </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Sohel%2C+S+H">Shahadat H. Sohel</a>, <a href="/search/cond-mat?searchtype=author&query=Kotecha%2C+R">Ramchandra Kotecha</a>, <a href="/search/cond-mat?searchtype=author&query=Khan%2C+I+S">Imran S Khan</a>, <a href="/search/cond-mat?searchtype=author&query=Heinselman%2C+K+N">Karen N. Heinselman</a>, <a href="/search/cond-mat?searchtype=author&query=Narumanchi%2C+S">Sreekant Narumanchi</a>, <a href="/search/cond-mat?searchtype=author&query=Tellekamp%2C+M+B">M Brooks Tellekamp</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2204.00112v1-abstract-short" style="display: inline;"> $尾$-Ga${_2}$O${_3}… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.00112v1-abstract-full').style.display = 'inline'; document.getElementById('2204.00112v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.00112v1-abstract-full" style="display: none;"> $尾$-Ga${_2}$O${_3}$ based semiconductor devices are expected to have significantly improved high-power and high-temperature performance due to its ultra-wide bandgap of close to 5 eV. However, the high-temperature operation of these ultra-wide-bandgap devices is usually limited by the relatively low 1-2 eV built-in potential at the Schottky barrier with most high-work-function metals. Here, we report heterojunction p-NiO/n-$尾$-Ga${_2}$O${_3}$ diodes fabrication and optimization for high-temperature device applications, demonstrating a current rectification ratio of more than 10${^6}$ at 410掳C. The NiO heterojunction diode can achieve higher turn-on voltage and lower reverse leakage current compared to the Ni-based Schottky diode fabricated on the same single crystal $尾$-Ga${_2}$O${_3}$ substrate, despite charge transport dominated by interfacial recombination. Electrical characterization and device modeling show that these advantages are due to a higher built-in potential and additional band offset. These results suggest that heterojunction p-n diodes based on $尾$-Ga${_2}$O${_3}$ can significantly improve high-temperature electronic device and sensor performance. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.00112v1-abstract-full').style.display = 'none'; document.getElementById('2204.00112v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 8 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2112.07474">arXiv:2112.07474</a> <span> [<a href="https://arxiv.org/pdf/2112.07474">pdf</a>, <a href="https://arxiv.org/format/2112.07474">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> Boron phosphide films by reactive sputtering: Searching for a p-type transparent conductor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Crovetto%2C+A">Andrea Crovetto</a>, <a href="/search/cond-mat?searchtype=author&query=Adamczyk%2C+J+M">Jesse M. Adamczyk</a>, <a href="/search/cond-mat?searchtype=author&query=Schnepf%2C+R+R">Rekha R. Schnepf</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+C+L">Craig L. Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Hempel%2C+H">Hannes Hempel</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S+R">Sage R. Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Toberer%2C+E+S">Eric S. Toberer</a>, <a href="/search/cond-mat?searchtype=author&query=Tamboli%2C+A+C">Adele C. Tamboli</a>, <a href="/search/cond-mat?searchtype=author&query=Unold%2C+T">Thomas Unold</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2112.07474v2-abstract-short" style="display: inline;"> With an indirect band gap in the visible and a direct band gap at a much higher energy, boron phosphide (BP) holds promise as an unconventional p-type transparent conductor. Previous experimental reports deal almost exclusively with epitaxial, nominally undoped BP films by chemical vapor deposition. High hole concentrations were often observed, but it is unclear if native defects alone can be resp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.07474v2-abstract-full').style.display = 'inline'; document.getElementById('2112.07474v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2112.07474v2-abstract-full" style="display: none;"> With an indirect band gap in the visible and a direct band gap at a much higher energy, boron phosphide (BP) holds promise as an unconventional p-type transparent conductor. Previous experimental reports deal almost exclusively with epitaxial, nominally undoped BP films by chemical vapor deposition. High hole concentrations were often observed, but it is unclear if native defects alone can be responsible for it. Besides, the feasibility of alternative deposition techniques has not been clarified and optical characterization is generally lacking. In this work, we demonstrate reactive sputtering of amorphous BP films, their partial crystallization in a P-containing annealing atmosphere, and extrinsic doping by C and Si. We obtain the highest hole concentration reported to date for p-type BP ($5 \times 10^{20}$ cm$^{-3}$) using C doping under B-rich conditions. We also confirm that bipolar doping is possible in BP. An anneal temperature of at least 1000 $^\circ$C is necessary for crystallization and dopant activation. Hole mobilities are low and indirect optical transitions are much stronger than predicted by theory. Low crystalline quality probably plays a role in both cases. High figures of merit for transparent conductors might be achievable in extrinsically doped BP films with improved crystalline quality. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2112.07474v2-abstract-full').style.display = 'none'; document.getElementById('2112.07474v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.06063">arXiv:2107.06063</a> <span> [<a href="https://arxiv.org/pdf/2107.06063">pdf</a>, <a href="https://arxiv.org/format/2107.06063">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevApplied.16.064064">10.1103/PhysRevApplied.16.064064 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Theoretical insights for Improving the Schottky-barrier Height at the Ga$_2$O$_3$/Pt Interface </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Therrien%2C+F">F茅lix Therrien</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovi%C4%87%2C+V">Vladan Stevanovi膰</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2107.06063v2-abstract-short" style="display: inline;"> In this work we study the Schottky barrier height (SBH) at the junction between $尾$-Ga$_2$O$_3$ and platinum, a system of great importance for the next generation of high-power and high-temperature electronic devices. Specifically, we obtain interfacial atomic structures at different orientations using our structure matching algorithm and compute their SBH using electronic structure calculations b… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.06063v2-abstract-full').style.display = 'inline'; document.getElementById('2107.06063v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.06063v2-abstract-full" style="display: none;"> In this work we study the Schottky barrier height (SBH) at the junction between $尾$-Ga$_2$O$_3$ and platinum, a system of great importance for the next generation of high-power and high-temperature electronic devices. Specifically, we obtain interfacial atomic structures at different orientations using our structure matching algorithm and compute their SBH using electronic structure calculations based on hybrid density functional theory. The orientation and strain of platinum are found to have little impact on the barrier height. In contrast, we find that decomposed water (H.OH), which could be present at the interface from Ga$_2$O$_3$ substrate preparation, has a strong influence on the SBH, in particular in the ($\overline{2}$01) orientation. The SBH can range from $\sim$2 eV for the pristine interface to nearly zero for the full H.OH coverage. This result suggests that SBH of $\sim$2~eV can be achieved for the Ga$_2$O$_3$($\overline{2}$01)/Pt junction using the substrate preparation methods that can reduce the amount of adsorbed water at the interface. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.06063v2-abstract-full').style.display = 'none'; document.getElementById('2107.06063v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 6 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Physical Review Applied 16.6 (2021): 064064 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.05280">arXiv:2107.05280</a> <span> [<a href="https://arxiv.org/pdf/2107.05280">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevMaterials.5.125405">10.1103/PhysRevMaterials.5.125405 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> n-type electrical conduction in SnS thin films </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Suzuki%2C+I">Issei Suzuki</a>, <a href="/search/cond-mat?searchtype=author&query=Kawanishi%2C+S">Sakiko Kawanishi</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S+R">Sage R. Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Lin%2C+Z">Zexin Lin</a>, <a href="/search/cond-mat?searchtype=author&query=Tsukuda%2C+S">Satoshi Tsukuda</a>, <a href="/search/cond-mat?searchtype=author&query=Shibata%2C+H">Hiroyuki Shibata</a>, <a href="/search/cond-mat?searchtype=author&query=Kim%2C+M">Minseok Kim</a>, <a href="/search/cond-mat?searchtype=author&query=Yanagi%2C+H">Hiroshi Yanagi</a>, <a href="/search/cond-mat?searchtype=author&query=Omata%2C+T">Takahisa Omata</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2107.05280v3-abstract-short" style="display: inline;"> Tin monosulfide (SnS) usually exhibits p-type conduction due to the low formation enthalpy of acceptor-type defects, and as a result n-type SnS thin films have never been obtained. This study realizes n-type conduction in SnS thin films for the first time by using RF-magnetron sputtering with Cl doping and sulfur plasma source during deposition. N-type SnS thin films are obtained at all the substr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.05280v3-abstract-full').style.display = 'inline'; document.getElementById('2107.05280v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.05280v3-abstract-full" style="display: none;"> Tin monosulfide (SnS) usually exhibits p-type conduction due to the low formation enthalpy of acceptor-type defects, and as a result n-type SnS thin films have never been obtained. This study realizes n-type conduction in SnS thin films for the first time by using RF-magnetron sputtering with Cl doping and sulfur plasma source during deposition. N-type SnS thin films are obtained at all the substrate temperatures employed in this study (221-341 C), exhibiting carrier concentrations and Hall mobilities of ~2 x 10 18 cm-3 and 0.1-1 cm V-1s-1, respectively. The films prepared without sulfur plasma source, on the other hand, exhibit p-type conduction despite containing a comparable amount of Cl donors. This is likely due to a significant amount of acceptor-type defects originating from sulfur deficiency in p-type films, which appears as a broad optical absorption within the band gap. The demonstration of n-type SnS thin films in this study is a breakthrough for the realization of SnS homojunction solar cells, which are expected to have a higher conversion efficiency than the conventional heterojunction SnS solar cells. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.05280v3-abstract-full').style.display = 'none'; document.getElementById('2107.05280v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 4 figures, 1 table</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.09752">arXiv:2106.09752</a> <span> [<a href="https://arxiv.org/pdf/2106.09752">pdf</a>, <a href="https://arxiv.org/format/2106.09752">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Two-step solid-state synthesis of ternary nitride materials </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Todd%2C+P+K">Paul K. Todd</a>, <a href="/search/cond-mat?searchtype=author&query=Fallon%2C+M+J">M. Jewels Fallon</a>, <a href="/search/cond-mat?searchtype=author&query=Neilson%2C+J+R">James R. Neilson</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2106.09752v2-abstract-short" style="display: inline;"> Ternary nitride materials hold promise for many optical, electronic, and refractory applications yet their preparation via solid-state synthesis remains challenging. Often, high pressures or reactive gasses are used to manipulate the effective chemical potential of nitrogen, yet these strategies require specialized equipment. Here we report on a simple two-step synthesis using ion-exchange reactio… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.09752v2-abstract-full').style.display = 'inline'; document.getElementById('2106.09752v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.09752v2-abstract-full" style="display: none;"> Ternary nitride materials hold promise for many optical, electronic, and refractory applications yet their preparation via solid-state synthesis remains challenging. Often, high pressures or reactive gasses are used to manipulate the effective chemical potential of nitrogen, yet these strategies require specialized equipment. Here we report on a simple two-step synthesis using ion-exchange reactions that yield rocksalt-derived MgZrN$_2$ and Mg$_2$NbN$_3$, as well as layered MgMoN$_2$. All three compounds show nearly temperature-independent and weak paramagnetic responses to an applied magnetic field at cryogenic temperatures indicating phase pure products. The key to synthesizing these ternary materials is an initial low-temperature step (300-450 $^{\circ}$C) to promote Mg-M-N bond formation. Then the products are annealed (800-900 $^{\circ}$C) to increase crystalline domains of the ternary product. Calorimetry experiments reveal that initial reaction temperatures are determined by phase transitions of reaction precursors, whereas heating directly to high temperatures results in decomposition. These two-step reactions provide a rational guide to material discovery of other bulk ternary nitrides. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.09752v2-abstract-full').style.display = 'none'; document.getElementById('2106.09752v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 August, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.05206">arXiv:2105.05206</a> <span> [<a href="https://arxiv.org/pdf/2105.05206">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1039/D1TA03791A">10.1039/D1TA03791A <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Combinatorial screening of crystal structure in Ba-Sr-Mn-Ce perovskite oxides with ABO3 stoichiometry </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Heo%2C+S+J">Su Jeong Heo</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.05206v2-abstract-short" style="display: inline;"> ABO3 oxides with the perovskite-related structures are attracting significant interest due to their promising physical and chemical properties for many applications requiring tunable chemistry, including fuel cells, catalysis, and electrochemical water splitting. Here we report on the crystal structure of the entire family of perovskite oxides with ABO3 stoichiometry, where A and B are Ba, Sr, Mn,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.05206v2-abstract-full').style.display = 'inline'; document.getElementById('2105.05206v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.05206v2-abstract-full" style="display: none;"> ABO3 oxides with the perovskite-related structures are attracting significant interest due to their promising physical and chemical properties for many applications requiring tunable chemistry, including fuel cells, catalysis, and electrochemical water splitting. Here we report on the crystal structure of the entire family of perovskite oxides with ABO3 stoichiometry, where A and B are Ba, Sr, Mn, Ce. Given the vast size of this chemically complex material system, exploration for stable perovskite-related structures with respect to its constituent elements and annealing temperature is performed by combinatorial pulsed laser deposition and spatially-resolved characterization of composition and structure. As a result of this high-throughput experimental study, we identify hexagonal perovskite-related polytypic transformation as a function of composition in the Ba1-xSrxMnO3 oxides after annealing at different temperatures. Furthermore, a hexagonal perovskite-related polytype is observed in a narrow composition-temperature range of the BaCexMn1-xO3 oxides. In contrast, a tetragonally-distorted perovskite is observed across a wider range of compositions and annealing temperatures in the Sr1-xCexMnO3 oxides. This structure stability is further enhanced along the BaCexMn1-xO3 - Sr1-xCexMnO3 pseudo-binary tie-line at x=0.25 by increasing Ba-incorporation and annealing temperature. These results indicate that the BaCexMn1-xO3 - Sr1-xCexMnO3 pseudo-binary oxide alloys (solid solutions) with tetragonal perovskite structure and broad composition-temperature range of stability are promising candidates for thermochemical water splitting applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.05206v2-abstract-full').style.display = 'none'; document.getElementById('2105.05206v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 11 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.05160">arXiv:2105.05160</a> <span> [<a href="https://arxiv.org/pdf/2105.05160">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Research Data Infrastructure for High-Throughput Experimental Materials Science </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Talley%2C+K+R">Kevin R. Talley</a>, <a href="/search/cond-mat?searchtype=author&query=White%2C+R">Robert White</a>, <a href="/search/cond-mat?searchtype=author&query=Wunder%2C+N">Nick Wunder</a>, <a href="/search/cond-mat?searchtype=author&query=Eash%2C+M">Matthew Eash</a>, <a href="/search/cond-mat?searchtype=author&query=Schwarting%2C+M">Marcus Schwarting</a>, <a href="/search/cond-mat?searchtype=author&query=Evenson%2C+D">Dave Evenson</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+J">John Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Tumas%2C+W">William Tumas</a>, <a href="/search/cond-mat?searchtype=author&query=Munch%2C+K">Kristin Munch</a>, <a href="/search/cond-mat?searchtype=author&query=Phillips%2C+C">Caleb Phillips</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.05160v1-abstract-short" style="display: inline;"> The High-Throughput Experimental Materials Database (HTEM-DB) is the endpoint repository for inorganic thin-film materials data collected during combinatorial experiments at the National Renewable Energy Laboratory (NREL). This unique data asset is enabled by the Research Data Infrastructure (RDI) - a set of custom data tools that collect, process, and store experimental data and metadata. Here, w… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.05160v1-abstract-full').style.display = 'inline'; document.getElementById('2105.05160v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.05160v1-abstract-full" style="display: none;"> The High-Throughput Experimental Materials Database (HTEM-DB) is the endpoint repository for inorganic thin-film materials data collected during combinatorial experiments at the National Renewable Energy Laboratory (NREL). This unique data asset is enabled by the Research Data Infrastructure (RDI) - a set of custom data tools that collect, process, and store experimental data and metadata. Here, we describe the experimental data-tool workflow from the RDI to the HTEM-DB to illustrate the strategies and best practices currently used for materials data at NREL. Integration of these data tools with the experimental processes establishes a data communication pipeline between experimental and data science communities. In doing so, this work motivates the creation of similar data workflows at other institutions to aggregate valuable data and increase its usefulness for future data studies. These types of investments can greatly accelerate the pace of learning and discovery in the materials science field, by making data accessible to new and rapidly evolving data methods. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.05160v1-abstract-full').style.display = 'none'; document.getElementById('2105.05160v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.16639">arXiv:2103.16639</a> <span> [<a href="https://arxiv.org/pdf/2103.16639">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/5.0051788">10.1063/5.0051788 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Computational Fermi level engineering and doping-type conversion of Ga2O3 via three-step synthesis process </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Goyal%2C+A">Anuj Goyal</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovi%C4%87%2C+V">Vladan Stevanovi膰</a>, <a href="/search/cond-mat?searchtype=author&query=Lany%2C+S">Stephan Lany</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2103.16639v1-abstract-short" style="display: inline;"> Ga2O3 is being actively explored for high-power and high-temperature electronics, deep-ultraviolet optoelectronics, and other applications. Efficient n-type doping of Ga2O3 has been achieved, but p-type doping faces fundamental obstacles due to compensation, deep acceptor levels, and the polaron transport mechanism of free holes. However, aside from achieving p-type conductivity, plenty of opportu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16639v1-abstract-full').style.display = 'inline'; document.getElementById('2103.16639v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.16639v1-abstract-full" style="display: none;"> Ga2O3 is being actively explored for high-power and high-temperature electronics, deep-ultraviolet optoelectronics, and other applications. Efficient n-type doping of Ga2O3 has been achieved, but p-type doping faces fundamental obstacles due to compensation, deep acceptor levels, and the polaron transport mechanism of free holes. However, aside from achieving p-type conductivity, plenty of opportunity exists to engineer the position of the Fermi level for improved design of Ga2O3 based devices. We use first-principles defect theory and defect equilibrium calculations to simulate a 3-step growth-annealing-quench synthesis protocol for hydrogen assisted Mg doping in beta-Ga2O3, taking into account the gas phase equilibrium between H2, O2 and H2O, which determines the H chemical potential. We predict Ga2O3 doping-type conversion to a net p-type regime after growth under reducing conditions in the presence of H2 followed by O-rich annealing, which is a similar process to the Mg acceptor activation by H removal in GaN. For equilibrium annealing there is an optimal temperature that maximizes the Ga2O3 net acceptor density for a given Mg doping level, which is further increased in the non-equilibrium annealing scenario without re-equilibration. After quenching to operating temperature, the Ga2O3 Fermi level drops below mid-gap down to about +1.5 eV above the valence band maximum, creating a significant number of uncompensated neutral MgGa0 acceptors. The Fermi level reduction down to +1.5 eV and suppression of free electron density in this doping type converted (NA > ND) Ga2O3 material is of significance and impact for the design of Ga2O3 power electronics devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16639v1-abstract-full').style.display = 'none'; document.getElementById('2103.16639v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.15805">arXiv:2103.15805</a> <span> [<a href="https://arxiv.org/pdf/2103.15805">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Double-site Substitution of Ce into (Ba, Sr)MnO3 Perovskites for Solar Thermochemical Hydrogen Production </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Heo%2C+S+J">Su Jeong Heo</a>, <a href="/search/cond-mat?searchtype=author&query=Sanders%2C+M">Michael Sanders</a>, <a href="/search/cond-mat?searchtype=author&query=O%27Hayre%2C+R+P">Ryan P. O'Hayre</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2103.15805v2-abstract-short" style="display: inline;"> Solar thermochemical hydrogen production (STCH) is a renewable alternative to hydrogen produced using fossil fuels. While serial bulk experimental methods can accurately measure STCH performance, screening chemically complex materials systems for new promising candidates is more challenging. Here we identify double-site Ce-substituted (Ba,Sr)MnO3 oxide perovskites as promising STCH candidates usin… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.15805v2-abstract-full').style.display = 'inline'; document.getElementById('2103.15805v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.15805v2-abstract-full" style="display: none;"> Solar thermochemical hydrogen production (STCH) is a renewable alternative to hydrogen produced using fossil fuels. While serial bulk experimental methods can accurately measure STCH performance, screening chemically complex materials systems for new promising candidates is more challenging. Here we identify double-site Ce-substituted (Ba,Sr)MnO3 oxide perovskites as promising STCH candidates using a combination of bulk synthesis and high-throughput thin film experiments. The Ce substitution on the B-site in 10H-BaMnO3 and on the A-site in 4P-SrMnO3 lead to 2-3x higher hydrogen production compared to CeO2, but these bulk single-site substituted perovskites suffer from incomplete reoxidation. Double-site Ce substitution on both A- and B-site in (Ba,Sr)MnO3 thin films increases Ce solubility and extends the stability of 10H and 4P structures, which is promising for their thermochemical reversibility. This study demonstrates a high-throughput experimental method for screening complex oxide materials for STCH applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.15805v2-abstract-full').style.display = 'none'; document.getElementById('2103.15805v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 June, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 29 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.08755">arXiv:2101.08755</a> <span> [<a href="https://arxiv.org/pdf/2101.08755">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1002/pssr.202100043">10.1002/pssr.202100043 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Improving Reproducibility of Sputter Deposited Ferroelectric Wurtzite Al0.6Sc0.4N Films using In-situ Optical Emission Spectrometry </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Drury%2C+D">Daniel Drury</a>, <a href="/search/cond-mat?searchtype=author&query=Yazawa%2C+K">Keisuke Yazawa</a>, <a href="/search/cond-mat?searchtype=author&query=Mis%2C+A">Allison Mis</a>, <a href="/search/cond-mat?searchtype=author&query=Talley%2C+K">Kevin Talley</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Brennecka%2C+G+L">Geoff L. Brennecka</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2101.08755v1-abstract-short" style="display: inline;"> High-Sc Al1-xScxN thin films are of tremendous interest because of their attractive piezoelectric and ferroelectric properties, but overall film quality and reproducibility are widely reported to suffer as x increases. In this study, we correlate the structure and electrical properties of Al0.6Sc0.4N with in-situ observations of glow discharge optical emission during growth. This in-situ technique… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.08755v1-abstract-full').style.display = 'inline'; document.getElementById('2101.08755v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.08755v1-abstract-full" style="display: none;"> High-Sc Al1-xScxN thin films are of tremendous interest because of their attractive piezoelectric and ferroelectric properties, but overall film quality and reproducibility are widely reported to suffer as x increases. In this study, we correlate the structure and electrical properties of Al0.6Sc0.4N with in-situ observations of glow discharge optical emission during growth. This in-situ technique uses changes in the Ar(I) and N2(I) emission lines of the glow discharge during growth to identify films that subsequently exhibit unacceptable structural and electrical performance. We show that a steady deposition throughout film growth produces ferroelectric Al0.6Sc0.4N with a reversible 80 渭C cm-1 polarization and 3.1 MV cm-1 coercive field. In other films deposited using identical settings, fluctuations in both Ar(I) and N2(I) line intensities correspond to decreased wurtzite phase purity, nm-scale changes to the film microstructure, and a non-ferroelectric response. These results illustrate the power of optical emission spectroscopy for tracking changes when fabricating process-sensitive samples such as high-Sc Al1-xScxN films. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.08755v1-abstract-full').style.display = 'none'; document.getElementById('2101.08755v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 4 figures in main, 4 figures in supplementary information</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.06612">arXiv:2101.06612</a> <span> [<a href="https://arxiv.org/pdf/2101.06612">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/5.0043613">10.1063/5.0043613 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Reduced Coercive Field in Epitaxial Thin Film of Ferroelectric Wurtzite Al0.7Sc0.3N </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Yazawa%2C+K">Keisuke Yazawa</a>, <a href="/search/cond-mat?searchtype=author&query=Drury%2C+D">Daniel Drury</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Brennecka%2C+G+L">Geoff L. Brennecka</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2101.06612v1-abstract-short" style="display: inline;"> The first epitaxial ferroelectric wurtzite film with clear polarization-electric field hysteresis behavior is presented. The coercive field of this epitaxial Al0.7Sc0.3N film on W/c-sapphire substrate is 0.4 +- 0.3 MV cm-1 (8 %) smaller than that of a conventional fiber textured film on a Pt/TiOx/SiO2/Si substrate, attributed to the 0.01 +- 0.007 脜 smaller c-axis lattice parameter in the epitaxial… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.06612v1-abstract-full').style.display = 'inline'; document.getElementById('2101.06612v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.06612v1-abstract-full" style="display: none;"> The first epitaxial ferroelectric wurtzite film with clear polarization-electric field hysteresis behavior is presented. The coercive field of this epitaxial Al0.7Sc0.3N film on W/c-sapphire substrate is 0.4 +- 0.3 MV cm-1 (8 %) smaller than that of a conventional fiber textured film on a Pt/TiOx/SiO2/Si substrate, attributed to the 0.01 +- 0.007 脜 smaller c-axis lattice parameter in the epitaxial film. The strain and decrease of the coercive field most likely originate from epitaxial strain rather than the mismatch in thermal coefficient of expansion. These results provide an insight for further coercive field reduction of novel wurtzite ferroelectrics using epitaxial mismatch strain. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.06612v1-abstract-full').style.display = 'none'; document.getElementById('2101.06612v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 17 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">The following article has been submitted to Applied Physics Letters. After it is published, it will be found at https://aip.scitation.org/journal/apl</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.06449">arXiv:2101.06449</a> <span> [<a href="https://arxiv.org/pdf/2101.06449">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1361-648X/abfab3">10.1088/1361-648X/abfab3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Synthesis of Zn2NbN3 ternary nitride semiconductor with wurtzite-derived crystal structure </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2101.06449v1-abstract-short" style="display: inline;"> Binary III-N nitride semiconductors with wurtzite crystal structure such as GaN and AlN have been long used in many practical applications ranging from optoelectronic to telecommunication. The structurally related ZnGeN2 or ZnSnN2 derived from the parent binary compounds by cation mutation (elemental substitution) have recently attracted attention, but such ternary nitride materials are mostly lim… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.06449v1-abstract-full').style.display = 'inline'; document.getElementById('2101.06449v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.06449v1-abstract-full" style="display: none;"> Binary III-N nitride semiconductors with wurtzite crystal structure such as GaN and AlN have been long used in many practical applications ranging from optoelectronic to telecommunication. The structurally related ZnGeN2 or ZnSnN2 derived from the parent binary compounds by cation mutation (elemental substitution) have recently attracted attention, but such ternary nitride materials are mostly limited to II-IV-N2 compositions. This paper reports on synthesis and characterization of zinc niobium nitride Zn2NbN3 - a previously unreported II2-V-N3 ternary nitride semiconductor. The Zn2NbN3 thin films are synthesized using a single-step adsorption-controlled growth, and a two-step deposition/annealing method that prevents loss of Zn and N. Measurements indicate that Zn2NbN3 crystalizes in wurtzite-derived structure, in contrast to chemically related rocksalt-derived Mg2NbN3 compound synthesized here for comparison using the two-step method. The estimated wurtzite lattice parameters are a = 3.36A and c = 5.26A, (c/a = 1.55), and the optical absorption onset is at 2.1 eV for this cation-disordered Zn2NbN3. For comparison, published computational studies predict cation-ordered Zn2NbN3 to be a semiconductor with effective wurtzite c/a = 1.62 and a band gap of 3.5 - 3.6 eV. Overall, this work expands the wurtzite family of nitride semiconductors, and suggests that other ternary nitrides should be possible to synthesize <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.06449v1-abstract-full').style.display = 'none'; document.getElementById('2101.06449v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.12455">arXiv:2012.12455</a> <span> [<a href="https://arxiv.org/pdf/2012.12455">pdf</a>, <a href="https://arxiv.org/format/2012.12455">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Disordered Systems and Neural Networks">cond-mat.dis-nn</span> </div> </div> <p class="title is-5 mathjax"> The role of disorder in the synthesis of metastable zinc zirconium nitrides </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Woods-Robinson%2C+R">Rachel Woods-Robinson</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovi%C4%87%2C+V">Vladan Stevanovi膰</a>, <a href="/search/cond-mat?searchtype=author&query=Lany%2C+S">Stephan Lany</a>, <a href="/search/cond-mat?searchtype=author&query=Heinselman%2C+K+N">Karen N. Heinselman</a>, <a href="/search/cond-mat?searchtype=author&query=Horton%2C+M+K">Matthew K. Horton</a>, <a href="/search/cond-mat?searchtype=author&query=Persson%2C+K+A">Kristin A. Persson</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2012.12455v3-abstract-short" style="display: inline;"> In materials science, it is often assumed that ground state crystal structures predicted by density functional theory are the easiest polymorphs to synthesize. Ternary nitride materials, with many possible metastable polymorphs, provide a rich materials space to study what influences thermodynamic stability and polymorph synthesizability. For example, ZnZrN2 is theoretically predicted at zero Kelv… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.12455v3-abstract-full').style.display = 'inline'; document.getElementById('2012.12455v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.12455v3-abstract-full" style="display: none;"> In materials science, it is often assumed that ground state crystal structures predicted by density functional theory are the easiest polymorphs to synthesize. Ternary nitride materials, with many possible metastable polymorphs, provide a rich materials space to study what influences thermodynamic stability and polymorph synthesizability. For example, ZnZrN2 is theoretically predicted at zero Kelvin to have an unusual layered "wurtsalt" ground state crystal structure with compelling optoelectronic properties, but it is unknown whether this structure can be realized experimentally under practical synthesis conditions. Here, we use combinatorial sputtering to synthesize hundreds of ZnxZr1-xNy thin film samples, and find metastable rocksalt-derived or boron-nitride-derived structures rather than the predicted wurtsalt structure. Using a statistical polymorph sampler approach, it is demonstrated that although rocksalt is the least stable polymorph at zero Kelvin, it becomes the most stable polymorph at high effective temperatures similar to those achieved using this sputter deposition method, and thus corroborates experimental results. Additional calculations show that this destabilization of the wurtsalt polymorph is due to configurational entropic and enthalpic effects, and that vibrational contributions are negligible. Specifically, rocksalt- and boron-nitride-derived structures become the most stable polymorphs in the presence of disorder because of higher tolerances to cation cross-substitution and off-stoichiometry than the wurtsalt structure. This understanding of the role of disorder tolerance in the synthesis of competing polymorphs can enable more accurate predictions of synthesizable crystal structures and their achievable material properties. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.12455v3-abstract-full').style.display = 'none'; document.getElementById('2012.12455v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 22 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2010.01635">arXiv:2010.01635</a> <span> [<a href="https://arxiv.org/pdf/2010.01635">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> $Mg_xZn_{1-x}O$ contact to $CuGa_3Se_5$ absorber for photovoltaic and photoelectrochemical devices </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Khan%2C+I+S">Imran S. Khan</a>, <a href="/search/cond-mat?searchtype=author&query=Muzzillo%2C+C+P">Christopher P. Muzzillo</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+C+L">Craig L. Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Norman%2C+A+G">Andrew G. Norman</a>, <a href="/search/cond-mat?searchtype=author&query=Young%2C+J">James Young</a>, <a href="/search/cond-mat?searchtype=author&query=Gaillard%2C+N">Nicolas Gaillard</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2010.01635v1-abstract-short" style="display: inline;"> $CuGa_3Se_5$ is a promising candidate material with wide band gap for top cells in tandem photovoltaic (PV) and photoelectrochemical (PEC) devices. However, traditional CdS contact layers used with other chalcopyrite absorbers are not suitable for $CuGa_3Se_5$ due to the higher position of its conduction band minimum. $Mg_xZn_{1-x}O… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.01635v1-abstract-full').style.display = 'inline'; document.getElementById('2010.01635v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2010.01635v1-abstract-full" style="display: none;"> $CuGa_3Se_5$ is a promising candidate material with wide band gap for top cells in tandem photovoltaic (PV) and photoelectrochemical (PEC) devices. However, traditional CdS contact layers used with other chalcopyrite absorbers are not suitable for $CuGa_3Se_5$ due to the higher position of its conduction band minimum. $Mg_xZn_{1-x}O$ is a transparent oxide with adjustable band gap and conduction band position as a function of magnesium composition, but its direct application is hindered by $CuGa_3Se_5$ surface oxidation. Here, $Mg_xZn_{1-x}O$ is investigated as a contact (n-type buffer or window) material to $CuGa_3Se_5$ absorbers pretreated in $Cd^{2+}$ solution, and an onset potential close to 1 V vs RHE in 10 mM hexaammineruthenium (III) chloride electrolyte is demonstrated. The $Cd^{2+}$ surface treatment changes the chemical composition and electronic structure of the $CuGa_3Se_5$ surface, as demonstrated by photoelectron spectroscopy measurements. The performance of $CuGa_3Se_5$ absorber with $Cd^{2+}$ treated surface in the solid-state test structure depends on the Zn/Mg ratio in the $Mg_xZn_{1-x}O$ layer. The measured open circuit voltage close to 1 V is promising for tandem PEC water splitting with $CuGa_3Se_5$/$Mg_xZn_{1-x}O$ top cells. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2010.01635v1-abstract-full').style.display = 'none'; document.getElementById('2010.01635v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2006.14714">arXiv:2006.14714</a> <span> [<a href="https://arxiv.org/pdf/2006.14714">pdf</a>, <a href="https://arxiv.org/format/2006.14714">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Thin Film Growth Effects on Electrical Conductivity in Entropy Stabilized Oxides </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Jacobson%2C+V">Valerie Jacobson</a>, <a href="/search/cond-mat?searchtype=author&query=Diercks%2C+D">Dave Diercks</a>, <a href="/search/cond-mat?searchtype=author&query=To%2C+B">Bobby To</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Brennecka%2C+G">Geoff Brennecka</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2006.14714v1-abstract-short" style="display: inline;"> Entropy stabilization has garnered significant attention as a new approach to designing novel materials. Much of the work in this area has focused on bulk ceramic processing, leaving entropy-stabilized thin films relatively underexplored. Following an extensive multi-variable investigation of polycrystalline (Mg$_{0.2}$Co$_{0.2}$Ni$_{0.2}$Cu$_{0.2}$Zn$_{0.2}$)O thin films deposited via pulsed lase… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.14714v1-abstract-full').style.display = 'inline'; document.getElementById('2006.14714v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2006.14714v1-abstract-full" style="display: none;"> Entropy stabilization has garnered significant attention as a new approach to designing novel materials. Much of the work in this area has focused on bulk ceramic processing, leaving entropy-stabilized thin films relatively underexplored. Following an extensive multi-variable investigation of polycrystalline (Mg$_{0.2}$Co$_{0.2}$Ni$_{0.2}$Cu$_{0.2}$Zn$_{0.2}$)O thin films deposited via pulsed laser deposition (PLD), it is shown here that substrate temperature and deposition pressure have strong and repeatable effects on film texture and lattice parameter. Further analysis shows that films deposited at lower temperatures and under lower oxygen chamber pressure are $\sim$40x more electrically conductive than otherwise identical films grown at higher temperature and pressure. This electronic conductivity is hypothesized to be the result of polaron hopping mediated by transition metal valence changes which compensate for oxygen off-stoichiometry. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.14714v1-abstract-full').style.display = 'none'; document.getElementById('2006.14714v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2004.08470">arXiv:2004.08470</a> <span> [<a href="https://arxiv.org/pdf/2004.08470">pdf</a>, <a href="https://arxiv.org/format/2004.08470">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1361-6463/aba6b8">10.1088/1361-6463/aba6b8 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Growth and Characterization of Homoepitaxial $尾$-Ga$_2$O$_3$ Layers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Tellekamp%2C+M+B">M. Brooks Tellekamp</a>, <a href="/search/cond-mat?searchtype=author&query=Heinselman%2C+K+N">Karen N. Heinselman</a>, <a href="/search/cond-mat?searchtype=author&query=Harvey%2C+S">Steve Harvey</a>, <a href="/search/cond-mat?searchtype=author&query=Khan%2C+I">Imran Khan</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2004.08470v2-abstract-short" style="display: inline;"> $尾$-Ga$_2$O$_3$ is a next-generation ultra wide bandgap semiconductor (E$_g… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.08470v2-abstract-full').style.display = 'inline'; document.getElementById('2004.08470v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.08470v2-abstract-full" style="display: none;"> $尾$-Ga$_2$O$_3$ is a next-generation ultra wide bandgap semiconductor (E$_g$ = 4.8 eV to 4.9 eV) that can be homoepitaxially grown on commercial substrates, enabling next-generation power electronic devices among other important applications. Analyzing the quality of deposited homoepitaxial layers used in such devices is challenging, in part due to the large probing depth in traditional x-ray diffraction (XRD) and also due to the surface-sensitive nature of atomic force microscopy (AFM). Here, a combination of evanescent grazing-incidence skew asymmetric XRD and AFM are investigated as an approach to effectively characterize the quality of homoepitaxial $尾$-Ga$_2$O$_3$ layers grown by molecular beam epitaxy at a variety of Ga/O flux ratios. Accounting for both structure and morphology, optimal films are achieved at a Ga/O ratio of $\sim$1.15, a conclusion that would not be possible to achieve by either XRD or AFM methods alone. Finally, fabricated Schottky barrier diodes with thicker homoepitaxial layers are characterized by $J-V$ and $C-V$ measurements, revealing an unintentional doping density of 4.3 $\times$ 10$^{16}$ cm$^{-3}$ - 2 $\times$ 10$^{17}$ cm$^{-3}$ in the epilayer. These results demonstrate the importance of complementary measurement methods for improving the quality of the $尾$-Ga$_2$O$_3$ homoepitaxial layers used in power electronic and other devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.08470v2-abstract-full').style.display = 'none'; document.getElementById('2004.08470v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2004.06862">arXiv:2004.06862</a> <span> [<a href="https://arxiv.org/pdf/2004.06862">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1021/acs.nanolett.0c02115">10.1021/acs.nanolett.0c02115 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Synthesis of tunable $SnS-TaS_2$ nanoscale superlattices </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Roberts%2C+D+M">Dennice M. Roberts</a>, <a href="/search/cond-mat?searchtype=author&query=Bardgett%2C+D">Dylan Bardgett</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+J+D">John D. Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Gorman%2C+B+P">Brian P. Gorman</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S+R">Sage R. Bauers</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2004.06862v1-abstract-short" style="display: inline;"> Nanoscale superlattices represent a compelling platform for designed materials as the specific identity and spatial arrangement of constituent layers can lead to tunable properties. A number of kinetically-stabilized layered chalcogenide nanocomposites have taken inspiration from misfit compounds, a thermodynamically stable class of materials formed of van der Waals-bonded (vdW) layers. This class… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.06862v1-abstract-full').style.display = 'inline'; document.getElementById('2004.06862v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2004.06862v1-abstract-full" style="display: none;"> Nanoscale superlattices represent a compelling platform for designed materials as the specific identity and spatial arrangement of constituent layers can lead to tunable properties. A number of kinetically-stabilized layered chalcogenide nanocomposites have taken inspiration from misfit compounds, a thermodynamically stable class of materials formed of van der Waals-bonded (vdW) layers. This class of vdW heterostructure superlattices have been reported in telluride and selenide chemistries, but have not yet been extended to sulfides. Here we present $SnS-TaS_2$ nanoscale superlattices with tunable layer architecture. Thin films are prepared from layered amorphous precursors and deposited to mimic the targeted superlattice; subsequent low temperature annealing activates self-assembly into designed nanocomposites. Structure and composition for materials are investigated that span stacking sequences between $[(SnS)_{1+未}]_3(TaS_2)_1$ and $(SnS)_7(TaS_2)_1$ using x-ray diffraction, x-ray fluorescence, and transmission electron microscopy. A graded deposition approach is implemented to stabilize heterostructures of multiple stacking sequences with a single preparation. Precise control over the architecture of such nanoscale superlattices is a critical path towards controlling the properties of quantum materials and constituent devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2004.06862v1-abstract-full').style.display = 'none'; document.getElementById('2004.06862v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 April, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.00633">arXiv:2001.00633</a> <span> [<a href="https://arxiv.org/pdf/2001.00633">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Synthesis of ferroelectric LaWN3 -- the first nitride perovskite </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Talley%2C+K+R">Kevin R. Talley</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+C+L">Craig L. Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Diercks%2C+D+R">David R. Diercks</a>, <a href="/search/cond-mat?searchtype=author&query=Brennecka%2C+G+L">Geoff L. Brennecka</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2001.00633v1-abstract-short" style="display: inline;"> Next generation telecommunication technologies would benefit from strong piezoelectric and ferroelectric response in materials that are compatible with nitride radio-frequency electronic devices. Ferroelectric oxides with perovskite structure have been used in sensors and actuators for half a century, and halide perovskites transformed photovoltaics research in the past decade, but neither of them… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.00633v1-abstract-full').style.display = 'inline'; document.getElementById('2001.00633v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.00633v1-abstract-full" style="display: none;"> Next generation telecommunication technologies would benefit from strong piezoelectric and ferroelectric response in materials that are compatible with nitride radio-frequency electronic devices. Ferroelectric oxides with perovskite structure have been used in sensors and actuators for half a century, and halide perovskites transformed photovoltaics research in the past decade, but neither of them is compatible with nitride semiconductors. Nitride perovskites, despite numerous computational predictions, have not been experimentally demonstrated and their properties remain unknown. Here we report the experimental realization of the first nitride perovskite: lanthanum tungsten nitride (LaWN3). Oxygen-free LaWN3 thin films in a polar perovskite structure are confirmed by spectroscopy, scattering, and microscopy techniques. Scanning probe measurements confirm a large piezoelectric response and strongly suggest ferroelectric behavior, making it the first stable nitride ferroelectric compound. These results should lead to integration of LaWN3 with nitride semiconductors for wireless telecommunication applications, while enabling synthesis of many other predicted nitride perovskites. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.00633v1-abstract-full').style.display = 'none'; document.getElementById('2001.00633v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1911.03368">arXiv:1911.03368</a> <span> [<a href="https://arxiv.org/pdf/1911.03368">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Oxygen Reduction Reaction and X-ray Photoelectron Spectroscopy of Sputtered Fe-N-C Films </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Xu%2C+Y">Yun Xu</a>, <a href="/search/cond-mat?searchtype=author&query=Dzara%2C+M+J">Michael J. Dzara</a>, <a href="/search/cond-mat?searchtype=author&query=Kabir%2C+S">Sadia Kabir</a>, <a href="/search/cond-mat?searchtype=author&query=Pylypenko%2C+S">Svitlana Pylypenko</a>, <a href="/search/cond-mat?searchtype=author&query=Neyerlin%2C+K">Kenneth Neyerlin</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1911.03368v1-abstract-short" style="display: inline;"> Electrocatalysts for the oxygen reduction reaction (ORR) based on complexes of iron and nitrogen in a carbon matrix (Fe-N-C) are a promising alternative to platinum group metal (PGM) based catalysts in polymer electrolyte membrane (PEM) fuel cells. Further improvements of Fe-N-C catalysts would benefit from model thin film studies of activity and stability of catalytic sites, but synthesis of Fe-N… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.03368v1-abstract-full').style.display = 'inline'; document.getElementById('1911.03368v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1911.03368v1-abstract-full" style="display: none;"> Electrocatalysts for the oxygen reduction reaction (ORR) based on complexes of iron and nitrogen in a carbon matrix (Fe-N-C) are a promising alternative to platinum group metal (PGM) based catalysts in polymer electrolyte membrane (PEM) fuel cells. Further improvements of Fe-N-C catalysts would benefit from model thin film studies of activity and stability of catalytic sites, but synthesis of Fe-N-C model thin films is challenging. Here we report on synthesis and characterization of Fe-N-C thin films produced by co-sputtering iron and carbon in a reactive nitrogen atmosphere onto removable glassy carbon rotating disk electrode (RDE) tips. Scanning electron microscopy (SEM) measurements indicate that the Fe-N-C films deposited at high temperature are smoother than the films annealed at high temperature. ORR activity measured on the thin Fe-N-C films is greater for both high-temperature samples than for the room-temperature sample. From the analysis of X-ray photoelectron spectroscopy (XPS) data, exposure of the films to high temperatures results in increased graphitization of the carbon with the Fe-N-C films, and increased relative amount of graphitic and hydrogenated nitrogen species. Overall the results of this study demonstrate the feasibility of a thin film model system approach for studying active sites in PGM-free catalysts. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.03368v1-abstract-full').style.display = 'none'; document.getElementById('1911.03368v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 8 November, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1910.08153">arXiv:1910.08153</a> <span> [<a href="https://arxiv.org/pdf/1910.08153">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1021/acs.chemrev.9b00600">10.1021/acs.chemrev.9b00600 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Wide band gap chalcogenide semiconductors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Woods-Robinson%2C+R">Rachel Woods-Robinson</a>, <a href="/search/cond-mat?searchtype=author&query=Han%2C+Y">Yanbing Han</a>, <a href="/search/cond-mat?searchtype=author&query=Zhang%2C+H">Hanyu Zhang</a>, <a href="/search/cond-mat?searchtype=author&query=Ablekim%2C+T">Tursun Ablekim</a>, <a href="/search/cond-mat?searchtype=author&query=Khan%2C+I">Imran Khan</a>, <a href="/search/cond-mat?searchtype=author&query=Persson%2C+K">Kristin Persson</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1910.08153v3-abstract-short" style="display: inline;"> Wide band gap semiconductors are essential for today's electronic devices and energy applications due to their high optical transparency, as well as controllable carrier concentration and electrical conductivity. There are many categories of materials that can be defined as wide band gap semiconductors. The most intensively investigated are transparent conductive oxides (TCOs) such as ITO and IGZO… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.08153v3-abstract-full').style.display = 'inline'; document.getElementById('1910.08153v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1910.08153v3-abstract-full" style="display: none;"> Wide band gap semiconductors are essential for today's electronic devices and energy applications due to their high optical transparency, as well as controllable carrier concentration and electrical conductivity. There are many categories of materials that can be defined as wide band gap semiconductors. The most intensively investigated are transparent conductive oxides (TCOs) such as ITO and IGZO used in displays, carbides and nitrides used in power electronics, as well as emerging halides (e.g. CuI) and 2D electronic materials used in various optoelectronic devices. Chalcogen-based (S, Se, Te) wide band gap semiconductors are less heavily investigated but stand out due to their propensity for p-type doping, high mobilities, high valence band positions (i.e. low ionization potentials), and broad applications in electronic devices such as CdTe solar cells. This manuscript provides a review of wide band gap chalcogenide semiconductors. First, we outline general materials design parameters of high performing transparent conductors. We proceed to summarize progress in wide band gap (Eg > 2 eV) chalcogenide materials, such as II-VI MCh binaries, CuMCh2 chalcopyrites, Cu3MCh4 sulvanites, mixed anion layered CuMCh(O,F), and 2D materials, among others, and discuss computational predictions of potential new candidates in this family, highlighting their optical and electrical properties. We finally review applications of chalcogenide wide band gap semiconductors, e.g. photovoltaic and photoelectrochemical solar cells, transparent transistors, and diodes, that employ wide band gap chalcogenides as either an active or passive layer. By examining, categorizing, and discussing prospective directions in wide band gap chalcogenides, this review aims to inspire continued research on this emerging class of transparent conductors and to enable future innovations for optoelectronic devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1910.08153v3-abstract-full').style.display = 'none'; document.getElementById('1910.08153v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 6 February, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 October, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1908.08287">arXiv:1908.08287</a> <span> [<a href="https://arxiv.org/pdf/1908.08287">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1674-1056/ab5d05">10.1088/1674-1056/ab5d05 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> High-throughput fabrication and semi-automated characterization of oxide thin film transistors </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Han%2C+Y">Yanbing Han</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S">Sage Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Zhang%2C+Q">Qun Zhang</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1908.08287v1-abstract-short" style="display: inline;"> High throughput experimental methods are known to accelerate the rate of research, development, and deployment of electronic materials. For example, thin films with lateral gradients in composition, thickness, or other parameters have been used alongside spatially-resolved characterization to assess how various physical factors affect material properties under varying measurement conditions. Simil… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1908.08287v1-abstract-full').style.display = 'inline'; document.getElementById('1908.08287v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1908.08287v1-abstract-full" style="display: none;"> High throughput experimental methods are known to accelerate the rate of research, development, and deployment of electronic materials. For example, thin films with lateral gradients in composition, thickness, or other parameters have been used alongside spatially-resolved characterization to assess how various physical factors affect material properties under varying measurement conditions. Similarly, multi-layer electronic devices that contain such graded thin films as one or more of their layers can also be characterized spatially in order to optimize the performance. In this work, we apply these high throughput experimental methods to thin film transistors (TFTs), demonstrating combinatorial device fabrication and semi-automated characterization using sputtered Indium-Gallium-Zinc-Oxide (IGZO) TFTs as a case study. We show that both extrinsic and intrinsic types of device gradients can be generated in a TFT library, such as channel thickness and length, channel cation compositions, and oxygen atmosphere during deposition. We also present a semi-automated method to measure the 44 devices fabricated on a 50x50mm substrate that can help to identify properly functioning TFTs in the library and finish the measurement in a short time. Finally, we propose a fully automated characterization system for similar TFT libraries, which can be coupled with high throughput data analysis. These results demonstrate that high throughput methods can accelerate the investigation of TFTs and other electronic devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1908.08287v1-abstract-full').style.display = 'none'; document.getElementById('1908.08287v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 August, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 8 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1905.10426">arXiv:1905.10426</a> <span> [<a href="https://arxiv.org/pdf/1905.10426">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Thin film synthesis of semiconductors in the Mg-Sb-N materials system </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Heinselman%2C+K+N">Karen N. Heinselman</a>, <a href="/search/cond-mat?searchtype=author&query=Lany%2C+S">Stephan Lany</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+J+D">John D. Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Talley%2C+K+R">Kevin R. Talley</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1905.10426v2-abstract-short" style="display: inline;"> Nitrides feature many interesting properties, such as a wide range of bandgaps suitable for optoelectronic devices including light-emitting diodes (LEDs), and piezoelectric response used in microelectromechanical systems (MEMS). Nitrides are also significantly underexplored compared to oxides and other chemistries, with many being thermochemically metastable, sparking interest from a basic science… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.10426v2-abstract-full').style.display = 'inline'; document.getElementById('1905.10426v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1905.10426v2-abstract-full" style="display: none;"> Nitrides feature many interesting properties, such as a wide range of bandgaps suitable for optoelectronic devices including light-emitting diodes (LEDs), and piezoelectric response used in microelectromechanical systems (MEMS). Nitrides are also significantly underexplored compared to oxides and other chemistries, with many being thermochemically metastable, sparking interest from a basic science point of view. This paper reports on experimental and computational exploration of the Mg-Sb-N material system, featuring both metastable materials and interesting semiconducting properties. Using sputter deposition, we discovered a new Mg2SbN3 nitride with a wurtzite-derived crystal structure and synthesized the antimonide-nitride Mg3SbN with an antiperovskite crystal structure for the first time in thin film form. Theoretical calculations indicate that Mg2SbN3 is metastable and has properties relevant to LEDs and MEMS, whereas Mg3SbN has a large dielectric constant (28蔚_0) and low hole effective masses (0.9m_0), of interest for photovoltaic solar cell absorbers. The experimental solar-matched 1.3 eV optical absorption onset of the Mg3SbN antiperovskite agrees with the theoretical prediction (1.3 eV direct, 1.1 eV indirect), and with the measurements of room-temperature near-bandgap photoluminescence. These results make an important contribution towards understanding semiconductor properties and chemical trends in the Mg-Sb-N materials system, paving the way to future practical applications of these novel materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.10426v2-abstract-full').style.display = 'none'; document.getElementById('1905.10426v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">25 page paper (double spaced) with 8 figures, 33 pages with SI</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1904.07989">arXiv:1904.07989</a> <span> [<a href="https://arxiv.org/pdf/1904.07989">pdf</a>, <a href="https://arxiv.org/format/1904.07989">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computational Physics">physics.comp-ph</span> </div> </div> <p class="title is-5 mathjax"> COMBIgor: data analysis package for combinatorial materials science </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Talley%2C+K+R">Kevin R. Talley</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S+R">Sage R. Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Melamed%2C+C+L">Celeste L. Melamed</a>, <a href="/search/cond-mat?searchtype=author&query=Papac%2C+M+C">Meagan C. Papac</a>, <a href="/search/cond-mat?searchtype=author&query=Heinselman%2C+K">Karen Heinselman</a>, <a href="/search/cond-mat?searchtype=author&query=Khan%2C+I">Imran Khan</a>, <a href="/search/cond-mat?searchtype=author&query=Roberts%2C+D+M">Dennice M. Roberts</a>, <a href="/search/cond-mat?searchtype=author&query=Jacobson%2C+V">Valerie Jacobson</a>, <a href="/search/cond-mat?searchtype=author&query=Mis%2C+A">Allison Mis</a>, <a href="/search/cond-mat?searchtype=author&query=Brennecka%2C+G+L">Geoff L. Brennecka</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+J+D">John D. Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1904.07989v2-abstract-short" style="display: inline;"> Combinatorial experiments involve synthesis of sample libraries with lateral composition gradients requiring spatially-resolved characterization of structure and properties. Due to maturation of combinatorial methods and their successful application in many fields, the modern combinatorial laboratory produces diverse and complex data sets requiring advanced analysis and visualization techniques. I… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.07989v2-abstract-full').style.display = 'inline'; document.getElementById('1904.07989v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1904.07989v2-abstract-full" style="display: none;"> Combinatorial experiments involve synthesis of sample libraries with lateral composition gradients requiring spatially-resolved characterization of structure and properties. Due to maturation of combinatorial methods and their successful application in many fields, the modern combinatorial laboratory produces diverse and complex data sets requiring advanced analysis and visualization techniques. In order to utilize these large data sets to uncover new knowledge, the combinatorial scientist must engage in data science. For data science tasks, most laboratories adopt common-purpose data management and visualization software. However, processing and cross-correlating data from various measurement tools is no small task for such generic programs. Here we describe COMBIgor, a purpose-built open-source software package written in the commercial Igor Pro environment, designed to offer a systematic approach to loading, storing, processing, and visualizing combinatorial data sets. It includes (1) methods for loading and storing data sets from combinatorial libraries, (2) routines for streamlined data processing, and (3) data analysis and visualization features to construct figures. Most importantly, COMBIgor is designed to be easily customized by a laboratory, group, or individual in order to integrate additional instruments and data-processing algorithms. Utilizing the capabilities of COMBIgor can significantly reduce the burden of data management on the combinatorial scientist. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1904.07989v2-abstract-full').style.display = 'none'; document.getElementById('1904.07989v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 April, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1810.05668">arXiv:1810.05668</a> <span> [<a href="https://arxiv.org/pdf/1810.05668">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1073/pnas.1904926116">10.1073/pnas.1904926116 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ternary Nitride Semiconductors in the Rocksalt Crystal Structure </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S+R">Sage R. Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Holder%2C+A">Aaron Holder</a>, <a href="/search/cond-mat?searchtype=author&query=Sun%2C+W">Wenhao Sun</a>, <a href="/search/cond-mat?searchtype=author&query=Melamed%2C+C+L">Celeste L. Melamed</a>, <a href="/search/cond-mat?searchtype=author&query=Woods-Robinson%2C+R">Rachel Woods-Robinson</a>, <a href="/search/cond-mat?searchtype=author&query=Mangum%2C+J">John Mangum</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+J">John Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Tumas%2C+W">William Tumas</a>, <a href="/search/cond-mat?searchtype=author&query=Gorman%2C+B">Brian Gorman</a>, <a href="/search/cond-mat?searchtype=author&query=Tamboli%2C+A">Adele Tamboli</a>, <a href="/search/cond-mat?searchtype=author&query=Ceder%2C+G">Gerbrand Ceder</a>, <a href="/search/cond-mat?searchtype=author&query=Lany%2C+S">Stephan Lany</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1810.05668v1-abstract-short" style="display: inline;"> Inorganic nitrides with wurtzite crystal structures are well-known semiconductors used in optoelectronic devices. In contrast, rocksalt-based nitrides are known for their metallic and refractory properties. Breaking this dichotomy, here we report on ternary nitride semiconductors with rocksalt crystal structures, remarkable optoelectronic properties, and the general chemical formula Mg$_{x}$TM… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.05668v1-abstract-full').style.display = 'inline'; document.getElementById('1810.05668v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1810.05668v1-abstract-full" style="display: none;"> Inorganic nitrides with wurtzite crystal structures are well-known semiconductors used in optoelectronic devices. In contrast, rocksalt-based nitrides are known for their metallic and refractory properties. Breaking this dichotomy, here we report on ternary nitride semiconductors with rocksalt crystal structures, remarkable optoelectronic properties, and the general chemical formula Mg$_{x}$TM$_{1-x}$N (TM=Ti, Zr, Hf, Nb). These compounds form over a broad metal composition range and our experiments show that Mg-rich compositions are nondegenerate semiconductors with visible-range optical absorption onsets (1.8-2.1 eV). Lattice parameters are compatible with growth on a variety of substrates, and epitaxially grown MgZrN$_{2}$ exhibits remarkable electron mobilities approaching 100 cm$^{2}$V$^{-1}$s$^{-1}$. Ab initio calculations reveal that these compounds have disorder-tunable optical properties, large dielectric constants and low carrier effective masses that are insensitive to disorder. Overall, these experimental and theoretical results highlight Mg$_{G-3}$TMN$_{G-2}$ rocksalts as a new class of semiconductor materials with promising properties for optoelectronic applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1810.05668v1-abstract-full').style.display = 'none'; document.getElementById('1810.05668v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 October, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2018. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1809.09202">arXiv:1809.09202</a> <span> [<a href="https://arxiv.org/pdf/1809.09202">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41563-019-0396-2">10.1038/s41563-019-0396-2 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A Map of the Inorganic Ternary Metal Nitrides </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Sun%2C+W">Wenhao Sun</a>, <a href="/search/cond-mat?searchtype=author&query=Bartel%2C+C">Christopher Bartel</a>, <a href="/search/cond-mat?searchtype=author&query=Arca%2C+E">Elisabetta Arca</a>, <a href="/search/cond-mat?searchtype=author&query=Bauers%2C+S">Sage Bauers</a>, <a href="/search/cond-mat?searchtype=author&query=Matthews%2C+B">Bethany Matthews</a>, <a href="/search/cond-mat?searchtype=author&query=Orva%C3%B1anos%2C+B">Bernardo Orva帽anos</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+B">Bor-Rong Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Toney%2C+M+F">Michael F. Toney</a>, <a href="/search/cond-mat?searchtype=author&query=Schelhas%2C+L+T">Laura T. Schelhas</a>, <a href="/search/cond-mat?searchtype=author&query=Tumas%2C+W">William Tumas</a>, <a href="/search/cond-mat?searchtype=author&query=Tate%2C+J">Janet Tate</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Lany%2C+S">Stephan Lany</a>, <a href="/search/cond-mat?searchtype=author&query=Holder%2C+A">Aaron Holder</a>, <a href="/search/cond-mat?searchtype=author&query=Ceder%2C+G">Gerbrand Ceder</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1809.09202v1-abstract-short" style="display: inline;"> Exploratory synthesis in novel chemical spaces is the essence of solid-state chemistry. However, uncharted chemical spaces can be difficult to navigate, especially when materials synthesis is challenging. Nitrides represent one such space, where stringent synthesis constraints have limited the exploration of this important class of functional materials. Here, we employ a suite of computational mat… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.09202v1-abstract-full').style.display = 'inline'; document.getElementById('1809.09202v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1809.09202v1-abstract-full" style="display: none;"> Exploratory synthesis in novel chemical spaces is the essence of solid-state chemistry. However, uncharted chemical spaces can be difficult to navigate, especially when materials synthesis is challenging. Nitrides represent one such space, where stringent synthesis constraints have limited the exploration of this important class of functional materials. Here, we employ a suite of computational materials discovery and informatics tools to construct a large stability map of the inorganic ternary metal nitrides. Our map clusters the ternary nitrides into chemical families with distinct stability and metastability, and highlights hundreds of promising new ternary nitride spaces for experimental investigation--from which we experimentally realized 7 new Zn- and Mg-based ternary nitrides. By extracting the mixed metallicity, ionicity, and covalency of solid-state bonding from the DFT-computed electron density, we reveal the complex interplay between chemistry, composition, and electronic structure in governing large-scale stability trends in ternary nitride materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1809.09202v1-abstract-full').style.display = 'none'; document.getElementById('1809.09202v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 September, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2018. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1708.00490">arXiv:1708.00490</a> <span> [<a href="https://arxiv.org/pdf/1708.00490">pdf</a>, <a href="https://arxiv.org/format/1708.00490">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevApplied.9.034026">10.1103/PhysRevApplied.9.034026 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Enhanced piezoelectric response of AlN via CrN alloying </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Manna%2C+S">Sukriti Manna</a>, <a href="/search/cond-mat?searchtype=author&query=Talley%2C+K+R">Kevin R. Talley</a>, <a href="/search/cond-mat?searchtype=author&query=Gorai%2C+P">Prashun Gorai</a>, <a href="/search/cond-mat?searchtype=author&query=Mangum%2C+J">John Mangum</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a>, <a href="/search/cond-mat?searchtype=author&query=Brennecka%2C+G+L">Geoff L. Brennecka</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovi%C4%87%2C+V">Vladan Stevanovi膰</a>, <a href="/search/cond-mat?searchtype=author&query=Ciobanu%2C+C+V">Cristian V. Ciobanu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1708.00490v5-abstract-short" style="display: inline;"> Since AlN has emerged as an important piezoelectric material for a wide variety of applications, efforts have been made to increase its piezoelectric response via alloying with transition metals that can substitute for Al in the wurtzite lattice. Herein, we report density functional theory calculations of structure and properties of the Cr-AlN system for Cr concentrations ranging past the wurtzite… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1708.00490v5-abstract-full').style.display = 'inline'; document.getElementById('1708.00490v5-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1708.00490v5-abstract-full" style="display: none;"> Since AlN has emerged as an important piezoelectric material for a wide variety of applications, efforts have been made to increase its piezoelectric response via alloying with transition metals that can substitute for Al in the wurtzite lattice. Herein, we report density functional theory calculations of structure and properties of the Cr-AlN system for Cr concentrations ranging past the wurtzite-rocksalt transition point. By studying the different contributions to the longitudinal piezoelectric coefficient, we propose that the physical origin of the enhanced piezoelectricity in Cr$_x$Al$_{1-x}$N alloys is the increase of the internal parameter $u$ of the wurtzite structure upon substitution of Al with the larger Cr ions. Among a set of wurtzite-structured materials, we have found that Cr-AlN has the most sensitive piezoelectric coefficient with respect to alloying concentration. Based on these results, we propose that Cr-AlN is a viable piezoelectric material whose properties can be tuned via Cr composition; we support this proposal by combinatorial synthesis experiments, which show that Cr can be incorporated in the AlN lattice up to 30\% before a detectable transition to rocksalt occurs. At this Cr content, the piezoelectric modulus $d_{33}$ is approximately four times larger than that of pure AlN. This finding, combined with the relative ease of synthesis, may propel Cr-AlN as the prime piezoelectric material for applications such as resonators and acoustic wave generators. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1708.00490v5-abstract-full').style.display = 'none'; document.getElementById('1708.00490v5-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 9 March, 2018; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 August, 2017; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2017. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Submitted to Physical Review Applied</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Applied 9, 034026 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1601.04647">arXiv:1601.04647</a> <span> [<a href="https://arxiv.org/pdf/1601.04647">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computational Physics">physics.comp-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/1.4945561">10.1063/1.4945561 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Synthesis of a mixed-valent tin nitride and considerations of its possible crystal structures </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Caskey%2C+C+M">Christopher M. Caskey</a>, <a href="/search/cond-mat?searchtype=author&query=Holder%2C+A">Aaron Holder</a>, <a href="/search/cond-mat?searchtype=author&query=Shulda%2C+S">Sarah Shulda</a>, <a href="/search/cond-mat?searchtype=author&query=Christensen%2C+S">Steve Christensen</a>, <a href="/search/cond-mat?searchtype=author&query=Diercks%2C+D">David Diercks</a>, <a href="/search/cond-mat?searchtype=author&query=Schwartz%2C+C+P">Craig P. Schwartz</a>, <a href="/search/cond-mat?searchtype=author&query=Biagioni%2C+D">David Biagioni</a>, <a href="/search/cond-mat?searchtype=author&query=Nordlund%2C+D">Dennis Nordlund</a>, <a href="/search/cond-mat?searchtype=author&query=Kukliansky%2C+A">Alon Kukliansky</a>, <a href="/search/cond-mat?searchtype=author&query=Natan%2C+A">Amir Natan</a>, <a href="/search/cond-mat?searchtype=author&query=Prendergast%2C+D">David Prendergast</a>, <a href="/search/cond-mat?searchtype=author&query=Orvananos%2C+B">Bernardo Orvananos</a>, <a href="/search/cond-mat?searchtype=author&query=Sun%2C+W">Wenhao Sun</a>, <a href="/search/cond-mat?searchtype=author&query=Zhang%2C+X">Xiuwen Zhang</a>, <a href="/search/cond-mat?searchtype=author&query=Ceder%2C+G">Gerbrand Ceder</a>, <a href="/search/cond-mat?searchtype=author&query=Tumas%2C+W">William Tumas</a>, <a href="/search/cond-mat?searchtype=author&query=Ginley%2C+D+S">David S. Ginley</a>, <a href="/search/cond-mat?searchtype=author&query=Perkins%2C+J+D">John D. Perkins</a>, <a href="/search/cond-mat?searchtype=author&query=Stevanovic%2C+V">Vladan Stevanovic</a>, <a href="/search/cond-mat?searchtype=author&query=Pylypenko%2C+S">Svitlana Pylypenko</a>, <a href="/search/cond-mat?searchtype=author&query=Lany%2C+S">Stephan Lany</a>, <a href="/search/cond-mat?searchtype=author&query=Richards%2C+R+M">Ryan M. Richards</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1601.04647v1-abstract-short" style="display: inline;"> Recent advances in theoretical structure prediction methods and high-throughput computational techniques are revolutionizing experimental discovery of the thermodynamically stable inorganic materials. Metastable materials represent a new frontier for studies, since even simple binary non ground state compounds of common elements may be awaiting discovery. However, there are significant research ch… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1601.04647v1-abstract-full').style.display = 'inline'; document.getElementById('1601.04647v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1601.04647v1-abstract-full" style="display: none;"> Recent advances in theoretical structure prediction methods and high-throughput computational techniques are revolutionizing experimental discovery of the thermodynamically stable inorganic materials. Metastable materials represent a new frontier for studies, since even simple binary non ground state compounds of common elements may be awaiting discovery. However, there are significant research challenges related to non-equilibrium thin film synthesis and crystal structure predictions, such as small strained crystals in the experimental samples and energy minimization based theoretical algorithms. Here we report on experimental synthesis and characterization, as well as theoretical first-principles calculations of a previously unreported mixed-valent binary tin nitride. Thin film experiments indicate that this novel material is N-deficient SnN with tin in the mixed II/IV valence state and a small low-symmetry unit cell. Theoretical calculations suggest that the most likely crystal structure has the space group 2 (SG2) related to the distorted delafossite (SG166), which is nearly 0.1 eV/atom above the ground state SnN polymorph. This observation is rationalized by the structural similarity of the SnN distorted delafossite to the chemically related Sn3N4 spinel compound, which provides a fresh scientific insight into the reasons for growth of polymorphs of the metastable material. In addition to reporting on the discovery of the simple binary SnN compound, this paper illustrates a possible way of combining a wide range of advanced characterization techniques with the first-principle property calculation methods, to elucidate the most likely crystal structure of the previously unreported metastable materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1601.04647v1-abstract-full').style.display = 'none'; document.getElementById('1601.04647v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 January, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2016. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1601.03362">arXiv:1601.03362</a> <span> [<a href="https://arxiv.org/pdf/1601.03362">pdf</a>, <a href="https://arxiv.org/format/1601.03362">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/1.4948244">10.1063/1.4948244 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Understanding and Control of Bipolar Doping in Copper Nitride </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Fioretti%2C+A+N">Angela N Fioretti</a>, <a href="/search/cond-mat?searchtype=author&query=Schwartz%2C+C+P">Craig P Schwartz</a>, <a href="/search/cond-mat?searchtype=author&query=Vinson%2C+J">John Vinson</a>, <a href="/search/cond-mat?searchtype=author&query=Nordlund%2C+D">Dennis Nordlund</a>, <a href="/search/cond-mat?searchtype=author&query=Prendergast%2C+D">David Prendergast</a>, <a href="/search/cond-mat?searchtype=author&query=Tamboli%2C+A+C">Adele C Tamboli</a>, <a href="/search/cond-mat?searchtype=author&query=Caskey%2C+C+M">Christopher M Caskey</a>, <a href="/search/cond-mat?searchtype=author&query=Tuomisto%2C+F">Filip Tuomisto</a>, <a href="/search/cond-mat?searchtype=author&query=Linez%2C+F">Florence Linez</a>, <a href="/search/cond-mat?searchtype=author&query=Christensen%2C+S+T">Steven T Christensen</a>, <a href="/search/cond-mat?searchtype=author&query=Toberer%2C+E+S">Eric S Toberer</a>, <a href="/search/cond-mat?searchtype=author&query=Lany%2C+S">Stephan Lany</a>, <a href="/search/cond-mat?searchtype=author&query=Zakutayev%2C+A">Andriy Zakutayev</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1601.03362v1-abstract-short" style="display: inline;"> Semiconductor materials that can be doped both n-type and p-type are desirable for diode-based applications and transistor technology. Copper nitride (Cu3N) is a metastable semiconductor with a solar-relevant bandgap that has been reported to exhibit bipolar doping behavior. However, deeper understanding and better control of the mechanism behind this behavior in Cu3N is currently lacking in the l… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1601.03362v1-abstract-full').style.display = 'inline'; document.getElementById('1601.03362v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1601.03362v1-abstract-full" style="display: none;"> Semiconductor materials that can be doped both n-type and p-type are desirable for diode-based applications and transistor technology. Copper nitride (Cu3N) is a metastable semiconductor with a solar-relevant bandgap that has been reported to exhibit bipolar doping behavior. However, deeper understanding and better control of the mechanism behind this behavior in Cu3N is currently lacking in the literature. In this work, we use combinatorial growth with a temperature gradient to demonstrate both conduction types of phase-pure, sputter-deposited Cu3N thin films. Room temperature Hall effect and Seebeck effect measurements show n-type Cu3N with 10^17 electrons/cm^3 for low growth temperature (~35 degrees C) and p-type with 10^15-10^16 holes/cm^3 for elevated growth temperatures (50-120 degrees C). Mobility for both types of Cu3N was ~0.1-1 cm^2/Vs. Additionally, temperature- dependent Hall effect measurements indicate that ionized defects are an important scattering mechanism in p-type films. By combining X-ray absorption spectroscopy and first-principles defect theory, we determined that V_Cu defects form preferentially in p-type Cu3N while Cu_i defects form preferentially in n-type Cu3N. Based on these theoretical and experimental results, we propose a kinetic defect formation mechanism for bipolar doping in Cu3N, that is also supported by positron annihilation experiments. Overall, the results of this work highlight the importance of kinetic processes in the defect physics of metastable materials, and provide a framework that can be applied when considering the properties of such materials in general. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1601.03362v1-abstract-full').style.display = 'none'; document.getElementById('1601.03362v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 13 January, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2016. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 8 figures, accepted manuscript</span> </p> </li> </ol> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" 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