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Title: Carrier providers or killers: The case of Cu defects in CdTe

Defects play important roles in semiconductors for optoelectronic applications. Common intuition is that defects with shallow levels act as carrier providers and defects with deep levels are carrier killers. Here, taking the Cu defects in CdTe as an example, we show that relatively shallow defects can play both roles. Using first-principles calculation methods combined with thermodynamic simulations, we study the dialectic effects of Cu-related defects on hole density and lifetime in bulk CdTe. Because CuCd can form a relatively shallow acceptor, we find that increased Cu incorporation into CdTe indeed can help achieve high hole density; however, too much Cu can cause significant non-radiative recombination. We discuss strategies to balance the contradictory effects of Cu defects based on the calculated impact of Cd chemical potential, copper defect concentrations, and annealing temperature on lifetime and hole density. Lastly, these findings advance the understanding of the potential complex defect behaviors of relatively shallow defect states in semiconductors.
Authors:
 [1] ;  [1] ; ORCiD logo [2]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Beijing Computational Science Research Center, Beijing (China)
Publication Date:
Report Number(s):
NREL/JA-5K00-69052
Journal ID: ISSN 0003-6951
Grant/Contract Number:
AC36-08GO28308
Type:
Accepted Manuscript
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 111; Journal Issue: 4; Journal ID: ISSN 0003-6951
Publisher:
American Institute of Physics (AIP)
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S); SunShot Initiative
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; metalloids; semiconductors; charge carriers; hole density; chemical potential
OSTI Identifier:
1375310
Alternate Identifier(s):
OSTI ID: 1372711

Yang, Ji -Hui, Metzger, Wyatt K., and Wei, Su -Huai. Carrier providers or killers: The case of Cu defects in CdTe. United States: N. p., Web. doi:10.1063/1.4986077.
Yang, Ji -Hui, Metzger, Wyatt K., & Wei, Su -Huai. Carrier providers or killers: The case of Cu defects in CdTe. United States. doi:10.1063/1.4986077.
Yang, Ji -Hui, Metzger, Wyatt K., and Wei, Su -Huai. 2017. "Carrier providers or killers: The case of Cu defects in CdTe". United States. doi:10.1063/1.4986077. https://www.osti.gov/servlets/purl/1375310.
@article{osti_1375310,
title = {Carrier providers or killers: The case of Cu defects in CdTe},
author = {Yang, Ji -Hui and Metzger, Wyatt K. and Wei, Su -Huai},
abstractNote = {Defects play important roles in semiconductors for optoelectronic applications. Common intuition is that defects with shallow levels act as carrier providers and defects with deep levels are carrier killers. Here, taking the Cu defects in CdTe as an example, we show that relatively shallow defects can play both roles. Using first-principles calculation methods combined with thermodynamic simulations, we study the dialectic effects of Cu-related defects on hole density and lifetime in bulk CdTe. Because CuCd can form a relatively shallow acceptor, we find that increased Cu incorporation into CdTe indeed can help achieve high hole density; however, too much Cu can cause significant non-radiative recombination. We discuss strategies to balance the contradictory effects of Cu defects based on the calculated impact of Cd chemical potential, copper defect concentrations, and annealing temperature on lifetime and hole density. Lastly, these findings advance the understanding of the potential complex defect behaviors of relatively shallow defect states in semiconductors.},
doi = {10.1063/1.4986077},
journal = {Applied Physics Letters},
number = 4,
volume = 111,
place = {United States},
year = {2017},
month = {7}
}

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