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Band Alignments of Ternary Wurtzite and Zincblende III-Nitrides Investigated by Hybrid Density Functional Theory
[Image: see text] Band gaps and electron affinities of binary and ternary, wurtzite (wz-) and zincblende (zb-) III-nitrides are investigated using a unified hybrid density functional theory, and band offsets between wz- and zb- alloys are calculated using Anderson’s electron affinity model. A conduc...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2020
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7057329/ https://www.ncbi.nlm.nih.gov/pubmed/32149218 http://dx.doi.org/10.1021/acsomega.9b03353 |
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author | Tsai, Yi-Chia Bayram, Can |
author_facet | Tsai, Yi-Chia Bayram, Can |
author_sort | Tsai, Yi-Chia |
collection | PubMed |
description | [Image: see text] Band gaps and electron affinities of binary and ternary, wurtzite (wz-) and zincblende (zb-) III-nitrides are investigated using a unified hybrid density functional theory, and band offsets between wz- and zb- alloys are calculated using Anderson’s electron affinity model. A conduction (and valence) band offset of 1.85 (0.89) eV has been calculated for zb-GaN/InN heterojunctions, which is 0.25 eV larger (and 0.26 eV smaller) than that of the wz- counterpart. Such polarization-free zb-GaN/InGaN/GaN quantum well structures with large conduction band offsets have the potential to suppress electron leakage current and quantum-confined Stark effects (QCSEs). Contrarily, the conduction (and valence) band offset of zb-AlN/GaN heterojunctions is calculated to be 1.32 (0.43) eV, which is 1.15 eV smaller (and 0.13 eV larger) than that of the wz- case. The significant reduction in zb-AlN/GaN band offsets is ascribed to the smaller and indirect band gap of zb-AlN—the direct-to-indirect crossover point in zb-Al(X)Ga(1–X)N is when X ∼ 65%. The small band gap of the zb-AlN barrier and the small conduction band offsets imply that electrons can be injected into zb-AlN/GaN/AlN quantum well heterostructures with small bias and less energy loss when captured by the quantum wells, respectively, i.e., loss as heat is reduced. The band gap of ternary III-nitrides does not linearly depend on alloy compositions, implying a nonlinear dependence of band offsets on compositions. As a result, the large bowing of the conduction band offset is identified and ascribed to the cation-like behavior of the conduction band minimum, while the linear dependence of the valence band offset on compositions is attributed to the anion-like character of the valence band maximum. |
format | Online Article Text |
id | pubmed-7057329 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-70573292020-03-06 Band Alignments of Ternary Wurtzite and Zincblende III-Nitrides Investigated by Hybrid Density Functional Theory Tsai, Yi-Chia Bayram, Can ACS Omega [Image: see text] Band gaps and electron affinities of binary and ternary, wurtzite (wz-) and zincblende (zb-) III-nitrides are investigated using a unified hybrid density functional theory, and band offsets between wz- and zb- alloys are calculated using Anderson’s electron affinity model. A conduction (and valence) band offset of 1.85 (0.89) eV has been calculated for zb-GaN/InN heterojunctions, which is 0.25 eV larger (and 0.26 eV smaller) than that of the wz- counterpart. Such polarization-free zb-GaN/InGaN/GaN quantum well structures with large conduction band offsets have the potential to suppress electron leakage current and quantum-confined Stark effects (QCSEs). Contrarily, the conduction (and valence) band offset of zb-AlN/GaN heterojunctions is calculated to be 1.32 (0.43) eV, which is 1.15 eV smaller (and 0.13 eV larger) than that of the wz- case. The significant reduction in zb-AlN/GaN band offsets is ascribed to the smaller and indirect band gap of zb-AlN—the direct-to-indirect crossover point in zb-Al(X)Ga(1–X)N is when X ∼ 65%. The small band gap of the zb-AlN barrier and the small conduction band offsets imply that electrons can be injected into zb-AlN/GaN/AlN quantum well heterostructures with small bias and less energy loss when captured by the quantum wells, respectively, i.e., loss as heat is reduced. The band gap of ternary III-nitrides does not linearly depend on alloy compositions, implying a nonlinear dependence of band offsets on compositions. As a result, the large bowing of the conduction band offset is identified and ascribed to the cation-like behavior of the conduction band minimum, while the linear dependence of the valence band offset on compositions is attributed to the anion-like character of the valence band maximum. American Chemical Society 2020-01-30 /pmc/articles/PMC7057329/ /pubmed/32149218 http://dx.doi.org/10.1021/acsomega.9b03353 Text en Copyright © 2020 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes. |
spellingShingle | Tsai, Yi-Chia Bayram, Can Band Alignments of Ternary Wurtzite and Zincblende III-Nitrides Investigated by Hybrid Density Functional Theory |
title | Band Alignments of Ternary Wurtzite and Zincblende
III-Nitrides Investigated by Hybrid Density Functional Theory |
title_full | Band Alignments of Ternary Wurtzite and Zincblende
III-Nitrides Investigated by Hybrid Density Functional Theory |
title_fullStr | Band Alignments of Ternary Wurtzite and Zincblende
III-Nitrides Investigated by Hybrid Density Functional Theory |
title_full_unstemmed | Band Alignments of Ternary Wurtzite and Zincblende
III-Nitrides Investigated by Hybrid Density Functional Theory |
title_short | Band Alignments of Ternary Wurtzite and Zincblende
III-Nitrides Investigated by Hybrid Density Functional Theory |
title_sort | band alignments of ternary wurtzite and zincblende
iii-nitrides investigated by hybrid density functional theory |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7057329/ https://www.ncbi.nlm.nih.gov/pubmed/32149218 http://dx.doi.org/10.1021/acsomega.9b03353 |
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