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Title: Experimental and theoretical comparison of Sb, As, and P diffusion mechanisms and doping in CdTe

Abstract

Fundamental material doping challenges have limited CdTe electro-optical applications. In this work, the As atomistic diffusion mechanisms in CdTe are examined by spatially resolving dopant incorporation in both single-crystalline and polycrystalline CdTe over a range of experimental conditions. Density-functional theory calculations predict experimental activation energies and indicate As diffuses slowly through the Te sublattice and quickly along GBs similar to Sb. Because of its atomic size and associated defect chemistry, As does not have a fast interstitial diffusion component similar to P. Experiments to incorporate and activate P, As, and Sb in polycrystalline CdTe are conducted to examine if ex-situ Group V doping can overcome historic polycrystalline doping limits. The distinct P, As, and Sb diffusion characteristics create different strategies for increasing hole density. Because fast interstitial diffusion is prominent for P, less aggressive diffusion conditions followed by Cd overpressure to relocate the Group V element to the Te lattice site is effective. For larger atoms, slower diffusion through the Te sublattice requires more aggressive diffusion, however further activation is not always necessary. Based on the new physical understanding, we have obtained greater than 10^16 cm^-3 hole density in polycrystalline CdTe films by As and P diffusion.

Authors:
ORCiD logo; ; ; ; ; ; ; ;
Publication Date:
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)
OSTI Identifier:
1417286
Report Number(s):
NREL/JA-5K00-68501
Journal ID: ISSN 0022-3727
DOE Contract Number:
AC36-08GO28308
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physics. D, Applied Physics
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CdTe; diffusion; doping; DFT

Citation Formats

Colegrove, Eric, Yang, Ji-Hui, Harvey, Steven P., Young, Matthew, Burst, James M., Duenow, Joel N., Albin, David S., Wei, Su-Huai, and Metzger, Wyatt. Experimental and theoretical comparison of Sb, As, and P diffusion mechanisms and doping in CdTe. United States: N. p., 2018. Web. doi:10.1088/1361-6463/aaa67e.
Colegrove, Eric, Yang, Ji-Hui, Harvey, Steven P., Young, Matthew, Burst, James M., Duenow, Joel N., Albin, David S., Wei, Su-Huai, & Metzger, Wyatt. Experimental and theoretical comparison of Sb, As, and P diffusion mechanisms and doping in CdTe. United States. doi:10.1088/1361-6463/aaa67e.
Colegrove, Eric, Yang, Ji-Hui, Harvey, Steven P., Young, Matthew, Burst, James M., Duenow, Joel N., Albin, David S., Wei, Su-Huai, and Metzger, Wyatt. 2018. "Experimental and theoretical comparison of Sb, As, and P diffusion mechanisms and doping in CdTe". United States. doi:10.1088/1361-6463/aaa67e.
@article{osti_1417286,
title = {Experimental and theoretical comparison of Sb, As, and P diffusion mechanisms and doping in CdTe},
author = {Colegrove, Eric and Yang, Ji-Hui and Harvey, Steven P. and Young, Matthew and Burst, James M. and Duenow, Joel N. and Albin, David S. and Wei, Su-Huai and Metzger, Wyatt},
abstractNote = {Fundamental material doping challenges have limited CdTe electro-optical applications. In this work, the As atomistic diffusion mechanisms in CdTe are examined by spatially resolving dopant incorporation in both single-crystalline and polycrystalline CdTe over a range of experimental conditions. Density-functional theory calculations predict experimental activation energies and indicate As diffuses slowly through the Te sublattice and quickly along GBs similar to Sb. Because of its atomic size and associated defect chemistry, As does not have a fast interstitial diffusion component similar to P. Experiments to incorporate and activate P, As, and Sb in polycrystalline CdTe are conducted to examine if ex-situ Group V doping can overcome historic polycrystalline doping limits. The distinct P, As, and Sb diffusion characteristics create different strategies for increasing hole density. Because fast interstitial diffusion is prominent for P, less aggressive diffusion conditions followed by Cd overpressure to relocate the Group V element to the Te lattice site is effective. For larger atoms, slower diffusion through the Te sublattice requires more aggressive diffusion, however further activation is not always necessary. Based on the new physical understanding, we have obtained greater than 10^16 cm^-3 hole density in polycrystalline CdTe films by As and P diffusion.},
doi = {10.1088/1361-6463/aaa67e},
journal = {Journal of Physics. D, Applied Physics},
number = ,
volume = ,
place = {United States},
year = 2018,
month = 1
}
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