Shell DFT-1/2 method towards engineering accuracy for semiconductors: GGA versus LDA

Fuente: arXiv
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Main Authors: Cui, Hanli, Yang, Shengxin, Yuan, Jun-Hui, Li, Li-Heng, Ye, Fan, Huang, Jinhai, Xue, Kan-Hao, Miao, Xiangshui
Format: Preprint
Published: 2022
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author Cui, Hanli
Yang, Shengxin
Yuan, Jun-Hui
Li, Li-Heng
Ye, Fan
Huang, Jinhai
Xue, Kan-Hao
Miao, Xiangshui
author_facet Cui, Hanli
Yang, Shengxin
Yuan, Jun-Hui
Li, Li-Heng
Ye, Fan
Huang, Jinhai
Xue, Kan-Hao
Miao, Xiangshui
contents The Kohn-Sham gaps of density functional theory (DFT) obtained in terms of local density approximation (LDA) or generalized gradient approximation (GGA) cannot be directly linked to the fundamental gaps of semiconductors, but in engineering there is a strong demand to match them through certain rectification methods. Shell DFT-1/2 (shDFT-1/2), as a variant of DFT-1/2, is a potential candidate to yield much improved band gaps for covalent semiconductors, but its accuracy depends on the LDA/GGA ground state, including optimized lattice parameters, basic Kohn-Sham gap before self-energy correction and the amount of self-energy correction that is specific to the exchange-correlation (XC) functional. In this work, we test the LDA/GGA as well as shDFT-1/2 results of six technically important covalent semiconductors Si, Ge, GaN, GaP, GaAs and GaSb, with an additional ionic insulator LiF for comparison. The impact of XC flavor (LDA, PBEsol, PBE and RPBE), either directly on the gap value, or indirectly through the optimized lattice constant, is examined comprehensively. Moreover, we test the impact of XC flavor on LDA/GGA and shDFT-1/2 gaps under the condition of fixed experimental lattice constants. In-depth analysis reveals the rule of reaching the best accuracy in calculating the electronic band structures of typical covalent semiconductors. Relevant parameters like lattice constant, self-consistency in shDFT-1/2 runs, as well as the exchange enhancement factor of GGA, are discussed in details.
format Preprint
id arxiv_https___arxiv_org_abs_2203_16020
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Shell DFT-1/2 method towards engineering accuracy for semiconductors: GGA versus LDA
Cui, Hanli
Yang, Shengxin
Yuan, Jun-Hui
Li, Li-Heng
Ye, Fan
Huang, Jinhai
Xue, Kan-Hao
Miao, Xiangshui
Materials Science
Computational Physics
The Kohn-Sham gaps of density functional theory (DFT) obtained in terms of local density approximation (LDA) or generalized gradient approximation (GGA) cannot be directly linked to the fundamental gaps of semiconductors, but in engineering there is a strong demand to match them through certain rectification methods. Shell DFT-1/2 (shDFT-1/2), as a variant of DFT-1/2, is a potential candidate to yield much improved band gaps for covalent semiconductors, but its accuracy depends on the LDA/GGA ground state, including optimized lattice parameters, basic Kohn-Sham gap before self-energy correction and the amount of self-energy correction that is specific to the exchange-correlation (XC) functional. In this work, we test the LDA/GGA as well as shDFT-1/2 results of six technically important covalent semiconductors Si, Ge, GaN, GaP, GaAs and GaSb, with an additional ionic insulator LiF for comparison. The impact of XC flavor (LDA, PBEsol, PBE and RPBE), either directly on the gap value, or indirectly through the optimized lattice constant, is examined comprehensively. Moreover, we test the impact of XC flavor on LDA/GGA and shDFT-1/2 gaps under the condition of fixed experimental lattice constants. In-depth analysis reveals the rule of reaching the best accuracy in calculating the electronic band structures of typical covalent semiconductors. Relevant parameters like lattice constant, self-consistency in shDFT-1/2 runs, as well as the exchange enhancement factor of GGA, are discussed in details.
title Shell DFT-1/2 method towards engineering accuracy for semiconductors: GGA versus LDA
topic Materials Science
Computational Physics
url https://arxiv.org/abs/2203.16020