skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Impact of extended defects on recombination in CdTe heterostructures grown by molecular beam epitaxy

Abstract

Heterostructures with CdTe and CdTe 1-xSex (x ~ 0.01) absorbers between two wider-band-gap Cd1-xMgxTe barriers (x ~ 0.25-0.3) were grown by molecular beam epitaxy to study carrier generation and recombination in bulk materials with passivated interfaces. Using a combination of confocal photoluminescence (PL), time-resolved PL, and low-temperature PL emission spectroscopy, two extended defect types were identified and the impact of these defects on charge-carrier recombination was analyzed. The dominant defects identified by confocal PL were dislocations in samples grown on (211)B CdTe substrates and crystallographic twinning-related defects in samples on (100)-oriented InSb substrates. Low-temperature PL shows that twin-related defects have a zero-phonon energy of 1.460 eV and a Huang-Rhys factor of 1.50, while dislocation-dominated samples have a 1.473-eV zero-phonon energy and a Huang-Rhys factor of 1.22. The charge carrier diffusion length near both types of defects is ~6 um, suggesting that recombination is limited by diffusion dynamics. For heterostructures with a low concentration of extended defects, the bulk lifetime was determined to be 2.2 us with an interface recombination velocity of 160 cm/s and an estimated radiative lifetime of 91 us.

Authors:
 [1]; ORCiD logo [2];  [3];  [2];  [3]; ORCiD logo [3]; ORCiD logo [3];  [3]; ORCiD logo [3];  [3];  [2]; ORCiD logo [3]
  1. Department of Physics, Colorado State University, Fort Collins, Colorado 80523, USA; National Renewable Energy Laboratory, Golden, Colorado 80401, USA
  2. National Renewable Energy Laboratory, Golden, Colorado 80401, USA
  3. Materials Science, Engineering and Commercialization Program, Texas State University, San Marcos, Texas 78666, USA
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:
1326171
Report Number(s):
NREL/JA-5K00-67149
Journal ID: ISSN 0003-6951
DOE Contract Number:  
AC36-08GO28308
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 9
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; photoluminescence; epitaxy; II-VI semiconductors; diffusion; III-V semiconductors

Citation Formats

Zaunbrecher, Katherine N., Kuciauskas, Darius, Swartz, Craig H., Dippo, Pat, Edirisooriya, Madhavie, Ogedengbe, Olanrewaju S., Sohal, Sandeep, Hancock, Bobby L., LeBlanc, Elizabeth G., Jayathilaka, Pathiraja A. R. D., Barnes, Teresa M., and Myers, Thomas H. Impact of extended defects on recombination in CdTe heterostructures grown by molecular beam epitaxy. United States: N. p., 2016. Web. doi:10.1063/1.4961989.
Zaunbrecher, Katherine N., Kuciauskas, Darius, Swartz, Craig H., Dippo, Pat, Edirisooriya, Madhavie, Ogedengbe, Olanrewaju S., Sohal, Sandeep, Hancock, Bobby L., LeBlanc, Elizabeth G., Jayathilaka, Pathiraja A. R. D., Barnes, Teresa M., & Myers, Thomas H. Impact of extended defects on recombination in CdTe heterostructures grown by molecular beam epitaxy. United States. doi:10.1063/1.4961989.
Zaunbrecher, Katherine N., Kuciauskas, Darius, Swartz, Craig H., Dippo, Pat, Edirisooriya, Madhavie, Ogedengbe, Olanrewaju S., Sohal, Sandeep, Hancock, Bobby L., LeBlanc, Elizabeth G., Jayathilaka, Pathiraja A. R. D., Barnes, Teresa M., and Myers, Thomas H. Mon . "Impact of extended defects on recombination in CdTe heterostructures grown by molecular beam epitaxy". United States. doi:10.1063/1.4961989.
@article{osti_1326171,
title = {Impact of extended defects on recombination in CdTe heterostructures grown by molecular beam epitaxy},
author = {Zaunbrecher, Katherine N. and Kuciauskas, Darius and Swartz, Craig H. and Dippo, Pat and Edirisooriya, Madhavie and Ogedengbe, Olanrewaju S. and Sohal, Sandeep and Hancock, Bobby L. and LeBlanc, Elizabeth G. and Jayathilaka, Pathiraja A. R. D. and Barnes, Teresa M. and Myers, Thomas H.},
abstractNote = {Heterostructures with CdTe and CdTe 1-xSex (x ~ 0.01) absorbers between two wider-band-gap Cd1-xMgxTe barriers (x ~ 0.25-0.3) were grown by molecular beam epitaxy to study carrier generation and recombination in bulk materials with passivated interfaces. Using a combination of confocal photoluminescence (PL), time-resolved PL, and low-temperature PL emission spectroscopy, two extended defect types were identified and the impact of these defects on charge-carrier recombination was analyzed. The dominant defects identified by confocal PL were dislocations in samples grown on (211)B CdTe substrates and crystallographic twinning-related defects in samples on (100)-oriented InSb substrates. Low-temperature PL shows that twin-related defects have a zero-phonon energy of 1.460 eV and a Huang-Rhys factor of 1.50, while dislocation-dominated samples have a 1.473-eV zero-phonon energy and a Huang-Rhys factor of 1.22. The charge carrier diffusion length near both types of defects is ~6 um, suggesting that recombination is limited by diffusion dynamics. For heterostructures with a low concentration of extended defects, the bulk lifetime was determined to be 2.2 us with an interface recombination velocity of 160 cm/s and an estimated radiative lifetime of 91 us.},
doi = {10.1063/1.4961989},
journal = {Applied Physics Letters},
number = 9,
volume = 109,
place = {United States},
year = {Mon Aug 29 00:00:00 EDT 2016},
month = {Mon Aug 29 00:00:00 EDT 2016}
}