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Title: Review on first-principles study of defect properties of CdTe as a solar cell absorber

Abstract

CdTe is one of the leading materials for high-efficiency, low-cost, and thin-film solar cells. In this work, we review the recent first-principles study of defect properties of CdTe and present that: (1) When only intrinsic defects are present, p-type doping in CdTe is weak and the hole density is low due to the relatively deep acceptor levels of Cd vacancy. (2) When only intrinsic defects present, the dominant non-radiative recombination center in p-type CdTe is Te-2+/Cd, which limits the carrier lifetime to be around 200 ns. (3) Extrinsic p-type doping in CdTe by replacing Te with group V elements generally will be limited by the formation of AX centers. This could be overcome through a non-equilibrium cooling process and the hole density can achieve 10^17 cm-3. However, the long-term stability will be a challenging issue. (4) Extrinsic p-type doping by replacing Cd with alkaline group I elements is limited by alkaline interstitials and a non-equilibrium cooling process can efficiently enhance the hole density to the order of 10^17 cm-3. (5) Cu and Cl treatments are discussed. In bulk CdTe, Cu can enhance p-type doping, but Cl is found to be unsuitable for this. Both Cu and Cl show segregation atmore » grain boundaries, especially at those with Te-Te wrong bonds. (6) External impurities are usually incorporated by diffusion. Therefore, the diffusion processes in CdTe are investigated. We find that cation interstitial (Nai, Cui) diffusion follows relatively simple diffusion paths, but anion diffusion (Cli, Pi) follows more complicated paths due to the degenerated defect wavefunctions.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1296604
Report Number(s):
NREL/JA-5K00-66955
Journal ID: ISSN 0268-1242
DOE Contract Number:
AC36-08GO28308
Resource Type:
Journal Article
Resource Relation:
Journal Name: Semiconductor Science and Technology; Journal Volume: 31; Journal Issue: 8
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; defect control; CdTe; solar cell

Citation Formats

Yang, Ji-Hui, Yin, Wan-Jian, Park, Ji-Sang, Ma, Jie, and Wei, Su-Huai. Review on first-principles study of defect properties of CdTe as a solar cell absorber. United States: N. p., 2016. Web. doi:10.1088/0268-1242/31/8/083002.
Yang, Ji-Hui, Yin, Wan-Jian, Park, Ji-Sang, Ma, Jie, & Wei, Su-Huai. Review on first-principles study of defect properties of CdTe as a solar cell absorber. United States. doi:10.1088/0268-1242/31/8/083002.
Yang, Ji-Hui, Yin, Wan-Jian, Park, Ji-Sang, Ma, Jie, and Wei, Su-Huai. 2016. "Review on first-principles study of defect properties of CdTe as a solar cell absorber". United States. doi:10.1088/0268-1242/31/8/083002.
@article{osti_1296604,
title = {Review on first-principles study of defect properties of CdTe as a solar cell absorber},
author = {Yang, Ji-Hui and Yin, Wan-Jian and Park, Ji-Sang and Ma, Jie and Wei, Su-Huai},
abstractNote = {CdTe is one of the leading materials for high-efficiency, low-cost, and thin-film solar cells. In this work, we review the recent first-principles study of defect properties of CdTe and present that: (1) When only intrinsic defects are present, p-type doping in CdTe is weak and the hole density is low due to the relatively deep acceptor levels of Cd vacancy. (2) When only intrinsic defects present, the dominant non-radiative recombination center in p-type CdTe is Te-2+/Cd, which limits the carrier lifetime to be around 200 ns. (3) Extrinsic p-type doping in CdTe by replacing Te with group V elements generally will be limited by the formation of AX centers. This could be overcome through a non-equilibrium cooling process and the hole density can achieve 10^17 cm-3. However, the long-term stability will be a challenging issue. (4) Extrinsic p-type doping by replacing Cd with alkaline group I elements is limited by alkaline interstitials and a non-equilibrium cooling process can efficiently enhance the hole density to the order of 10^17 cm-3. (5) Cu and Cl treatments are discussed. In bulk CdTe, Cu can enhance p-type doping, but Cl is found to be unsuitable for this. Both Cu and Cl show segregation at grain boundaries, especially at those with Te-Te wrong bonds. (6) External impurities are usually incorporated by diffusion. Therefore, the diffusion processes in CdTe are investigated. We find that cation interstitial (Nai, Cui) diffusion follows relatively simple diffusion paths, but anion diffusion (Cli, Pi) follows more complicated paths due to the degenerated defect wavefunctions.},
doi = {10.1088/0268-1242/31/8/083002},
journal = {Semiconductor Science and Technology},
number = 8,
volume = 31,
place = {United States},
year = 2016,
month = 7
}
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