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Title: Recombination in Low-Bandgap InGaAs

Abstract

We review our investigation of recombination in In{sub x}Ga{sub 1-x}As with indium concentrations ranging between x=0.53 (i.e., lattice-matched to InP) and x=0.78. External radiative efficiency measurements were used to study how defect-related and Auger mechanisms compete with radiative recombination. The results indicated that deep mid-gap levels facilitate defect-related recombination in lattice-matched InGaAs while shallower levels play a more important role in the indium-rich alloys. Subsequent sub-bandgap photoluminescence measurements confirmed the presence of deep levels in the lattice-matched InGaAs. The superlinear excitation dependence of the sub-gap emission led to a defect-related deep-donor/shallow-acceptor pair model. Recent cathodoluminescence measurements of the subgap transitions show no spatial contrast, supporting the assignment of this mechanism to evenly distributed point defects. We hypothesize that the deep states observed in lattice-matched InGaAs are related to imperfections in the incorporation of indium or gallium, which become less likely as the indium concentration is increased.

Authors:
;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
943983
DOE Contract Number:
AC36-99-GO10337
Resource Type:
Conference
Resource Relation:
Conference: [Proceedings] 2006 IEEE 4th World Conference on Photovoltaic Energy Conversion (WCPEC-4), 7-12 May 2006, Waikoloa, Hawaii
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; ALLOYS; CATHODOLUMINESCENCE; DEFECTS; EFFICIENCY; ENERGY CONVERSION; EXCITATION; GALLIUM; INDIUM; PHOTOLUMINESCENCE; POINT DEFECTS; RECOMBINATION; Solar Energy - Photovoltaics

Citation Formats

Gfroerer, T. H., and Wanlass, M. W.. Recombination in Low-Bandgap InGaAs. United States: N. p., 2006. Web. doi:10.1109/WCPEC.2006.279572.
Gfroerer, T. H., & Wanlass, M. W.. Recombination in Low-Bandgap InGaAs. United States. doi:10.1109/WCPEC.2006.279572.
Gfroerer, T. H., and Wanlass, M. W.. Sun . "Recombination in Low-Bandgap InGaAs". United States. doi:10.1109/WCPEC.2006.279572.
@article{osti_943983,
title = {Recombination in Low-Bandgap InGaAs},
author = {Gfroerer, T. H. and Wanlass, M. W.},
abstractNote = {We review our investigation of recombination in In{sub x}Ga{sub 1-x}As with indium concentrations ranging between x=0.53 (i.e., lattice-matched to InP) and x=0.78. External radiative efficiency measurements were used to study how defect-related and Auger mechanisms compete with radiative recombination. The results indicated that deep mid-gap levels facilitate defect-related recombination in lattice-matched InGaAs while shallower levels play a more important role in the indium-rich alloys. Subsequent sub-bandgap photoluminescence measurements confirmed the presence of deep levels in the lattice-matched InGaAs. The superlinear excitation dependence of the sub-gap emission led to a defect-related deep-donor/shallow-acceptor pair model. Recent cathodoluminescence measurements of the subgap transitions show no spatial contrast, supporting the assignment of this mechanism to evenly distributed point defects. We hypothesize that the deep states observed in lattice-matched InGaAs are related to imperfections in the incorporation of indium or gallium, which become less likely as the indium concentration is increased.},
doi = {10.1109/WCPEC.2006.279572},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}

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