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Title: Self-compensation in arsenic doping of CdTe

Efficient p-type doping in CdTe has remained a critical challenge for decades, limiting the performance of CdTe-based semiconductor devices. Arsenic is a promising p-type dopant; however, reproducible doping with high concentration is difficult and carrier lifetime is low. We systematically studied defect structures in As-doped CdTe using high-purity single crystal wafers to investigate the mechanisms that limit p-type doping. Two As-doped CdTe with varying acceptor density and two undoped CdTe were grown in Cd-rich and Te-rich environments. The defect structures were investigated by thermoelectric-effect spectroscopy (TEES), and first-principles calculations were used for identifying and assigning the experimentally observed defects. Measurements revealed activation of As is very low in both As-doped samples with very short lifetimes indicating strong compensation and the presence of significant carrier trapping defects. Defect studies suggest two acceptors and one donor level were introduced by As doping with activation energies at ~88 meV, ~293 meV and ~377 meV. In particular, the peak shown at ~162 K in the TEES spectra is very prominent in both As-doped samples, indicating a signature of AX-center donors. In conclusion, the AX-centers are believed to be responsible for most of the compensation because of their low formation energy and very prominent peakmore » intensity in TEES spectra.« less
Authors:
ORCiD logo [1] ;  [2] ;  [3] ;  [4] ;  [4] ;  [4] ;  [4] ;  [5] ; ORCiD logo [2]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States); Washington State Univ., Pullman, WA (United States)
  2. Washington State Univ., Pullman, WA (United States)
  3. Soochow Univ., Suzhou (China)
  4. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  5. Beijing Computational Science Research Center, Beijing (China)
Publication Date:
Report Number(s):
NREL/JA-5K00-68633
Journal ID: ISSN 2045-2322
Grant/Contract Number:
AC36-08GO28308
Type:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 7; Journal Issue: 1; Journal ID: ISSN 2045-2322
Publisher:
Nature Publishing Group
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)
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; doping; CdTe; compensation; arsenic
OSTI Identifier:
1372626