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Title: Understanding and reducing deleterious defects in the metastable alloy GaAsBi

Abstract

Technological applications of novel metastable materials are frequently inhibited by abundant defects residing in these materials. Using first-principles methods, we investigate the defect thermodynamics and phase segregation in the technologically important metastable alloy GaAsBi. Our calculations predict defect energy levels in good agreement with those from numerous previous experiments and clarify the defect structures giving rise to these levels. We find that vacancies in some charge states become metastable or unstable with respect to antisite formation, and this instability is a general characteristic of zincblende semiconductors with small ionicity. The dominant point defects that degrade the electronic and optical performances are predicted to be As Ga, Bi Ga, As Ga+Bi As, Bi Ga+Bi As, V Ga and V Ga+Bi As, of which the first four and last two defects are minority-electron and minority-hole traps, respectively. V Ga is also observed to have a critical role in controlling metastable Bi supersaturation by mediating Bi diffusion and clustering. To reduce the influences of these deleterious defects, we suggest shifting the growth away from an As-rich condition and/or using hydrogen passivation to reduce the minority-carrier traps. In conclusion, we expect this work to aid in the applications of GaAsBi for novel electronic andmore » optoelectronic devices and to illuminate the control of deleterious defects in other metastable materials.« less

Authors:
 [1];  [1];  [2];  [1];  [3]; ORCiD logo [1]
  1. Univ. of Wisconsin, Madison, WI (United States). Dept. of Materials Science and Engineering
  2. Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemistry
  3. Univ. of Wisconsin, Madison, WI (United States). Dept. of Chemical and Biological Engineering
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1489252
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Accepted Manuscript
Journal Name:
NPG Asia Materials
Additional Journal Information:
Journal Volume: 9; Journal Issue: 1; Journal ID: ISSN 1884-4049
Publisher:
Nature Publishing Group Asia
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Luo, Guangfu, Yang, Shujiang, Jenness, Glen R., Song, Zhewen, Kuech, Thomas F., and Morgan, Dane. Understanding and reducing deleterious defects in the metastable alloy GaAsBi. United States: N. p., 2017. Web. doi:10.1038/am.2016.201.
Luo, Guangfu, Yang, Shujiang, Jenness, Glen R., Song, Zhewen, Kuech, Thomas F., & Morgan, Dane. Understanding and reducing deleterious defects in the metastable alloy GaAsBi. United States. doi:10.1038/am.2016.201.
Luo, Guangfu, Yang, Shujiang, Jenness, Glen R., Song, Zhewen, Kuech, Thomas F., and Morgan, Dane. Fri . "Understanding and reducing deleterious defects in the metastable alloy GaAsBi". United States. doi:10.1038/am.2016.201. https://www.osti.gov/servlets/purl/1489252.
@article{osti_1489252,
title = {Understanding and reducing deleterious defects in the metastable alloy GaAsBi},
author = {Luo, Guangfu and Yang, Shujiang and Jenness, Glen R. and Song, Zhewen and Kuech, Thomas F. and Morgan, Dane},
abstractNote = {Technological applications of novel metastable materials are frequently inhibited by abundant defects residing in these materials. Using first-principles methods, we investigate the defect thermodynamics and phase segregation in the technologically important metastable alloy GaAsBi. Our calculations predict defect energy levels in good agreement with those from numerous previous experiments and clarify the defect structures giving rise to these levels. We find that vacancies in some charge states become metastable or unstable with respect to antisite formation, and this instability is a general characteristic of zincblende semiconductors with small ionicity. The dominant point defects that degrade the electronic and optical performances are predicted to be AsGa, BiGa, AsGa+BiAs, BiGa+BiAs, VGa and VGa+BiAs, of which the first four and last two defects are minority-electron and minority-hole traps, respectively. VGa is also observed to have a critical role in controlling metastable Bi supersaturation by mediating Bi diffusion and clustering. To reduce the influences of these deleterious defects, we suggest shifting the growth away from an As-rich condition and/or using hydrogen passivation to reduce the minority-carrier traps. In conclusion, we expect this work to aid in the applications of GaAsBi for novel electronic and optoelectronic devices and to illuminate the control of deleterious defects in other metastable materials.},
doi = {10.1038/am.2016.201},
journal = {NPG Asia Materials},
number = 1,
volume = 9,
place = {United States},
year = {2017},
month = {1}
}

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Works referenced in this record:

Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set
journal, October 1996