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Title: Long carrier lifetimes in large-grain polycrystalline CdTe without CdCl{sub 2}

Abstract

For decades, polycrystalline CdTe thin films for solar applications have been restricted to grain sizes of microns or less whereas other semiconductors such as silicon and perovskites have produced devices with grains ranging from less than a micron to more than 1 mm. Because the lifetimes in as-deposited polycrystalline CdTe films are typically limited to less than a few hundred picoseconds, a CdCl{sub 2} treatment is generally used to improve the lifetime; but this treatment may limit the achievable hole density by compensation. Here, we establish methods to produce CdTe films with grain sizes ranging from hundreds of nanometers to several hundred microns by close-spaced sublimation at industrial manufacturing growth rates. Two-photon excitation photoluminescence spectroscopy shows a positive correlation of lifetime with grain size. Large-grain, as-deposited CdTe exhibits lifetimes exceeding 10 ns without Cl, S, O, or Cu. This uncompensated material allows dopants such as P to achieve a hole density of 10{sup 16 }cm{sup −3}, which is an order of magnitude higher than standard CdCl{sub 2}-treated devices, without compromising the lifetime.

Authors:
; ; ; ; ; ; ; ; ;  [1]
  1. National Renewable Energy Laboratory, 15013 Denver West Pkwy. Golden, Colorado 80401 (United States)
Publication Date:
OSTI Identifier:
22590667
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 108; Journal Issue: 26; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CADMIUM CHLORIDES; CADMIUM TELLURIDES; CARRIER LIFETIME; DOPED MATERIALS; EXCITATION; GRAIN SIZE; HOLES; PEROVSKITES; PHOTOLUMINESCENCE; POLYCRYSTALS; SEMICONDUCTOR MATERIALS; SPECTROSCOPY; SUBLIMATION; THIN FILMS

Citation Formats

Jensen, S. A., E-mail: Soren.Jensen@nrel.gov, E-mail: Wyatt.Metzger@nrel.gov, Burst, J. M., Duenow, J. N., Guthrey, H. L., Moseley, J., Moutinho, H. R., Johnston, S. W., Kanevce, A., Al-Jassim, M. M., and Metzger, W. K., E-mail: Soren.Jensen@nrel.gov, E-mail: Wyatt.Metzger@nrel.gov. Long carrier lifetimes in large-grain polycrystalline CdTe without CdCl{sub 2}. United States: N. p., 2016. Web. doi:10.1063/1.4954904.
Jensen, S. A., E-mail: Soren.Jensen@nrel.gov, E-mail: Wyatt.Metzger@nrel.gov, Burst, J. M., Duenow, J. N., Guthrey, H. L., Moseley, J., Moutinho, H. R., Johnston, S. W., Kanevce, A., Al-Jassim, M. M., & Metzger, W. K., E-mail: Soren.Jensen@nrel.gov, E-mail: Wyatt.Metzger@nrel.gov. Long carrier lifetimes in large-grain polycrystalline CdTe without CdCl{sub 2}. United States. doi:10.1063/1.4954904.
Jensen, S. A., E-mail: Soren.Jensen@nrel.gov, E-mail: Wyatt.Metzger@nrel.gov, Burst, J. M., Duenow, J. N., Guthrey, H. L., Moseley, J., Moutinho, H. R., Johnston, S. W., Kanevce, A., Al-Jassim, M. M., and Metzger, W. K., E-mail: Soren.Jensen@nrel.gov, E-mail: Wyatt.Metzger@nrel.gov. Mon . "Long carrier lifetimes in large-grain polycrystalline CdTe without CdCl{sub 2}". United States. doi:10.1063/1.4954904.
@article{osti_22590667,
title = {Long carrier lifetimes in large-grain polycrystalline CdTe without CdCl{sub 2}},
author = {Jensen, S. A., E-mail: Soren.Jensen@nrel.gov, E-mail: Wyatt.Metzger@nrel.gov and Burst, J. M. and Duenow, J. N. and Guthrey, H. L. and Moseley, J. and Moutinho, H. R. and Johnston, S. W. and Kanevce, A. and Al-Jassim, M. M. and Metzger, W. K., E-mail: Soren.Jensen@nrel.gov, E-mail: Wyatt.Metzger@nrel.gov},
abstractNote = {For decades, polycrystalline CdTe thin films for solar applications have been restricted to grain sizes of microns or less whereas other semiconductors such as silicon and perovskites have produced devices with grains ranging from less than a micron to more than 1 mm. Because the lifetimes in as-deposited polycrystalline CdTe films are typically limited to less than a few hundred picoseconds, a CdCl{sub 2} treatment is generally used to improve the lifetime; but this treatment may limit the achievable hole density by compensation. Here, we establish methods to produce CdTe films with grain sizes ranging from hundreds of nanometers to several hundred microns by close-spaced sublimation at industrial manufacturing growth rates. Two-photon excitation photoluminescence spectroscopy shows a positive correlation of lifetime with grain size. Large-grain, as-deposited CdTe exhibits lifetimes exceeding 10 ns without Cl, S, O, or Cu. This uncompensated material allows dopants such as P to achieve a hole density of 10{sup 16 }cm{sup −3}, which is an order of magnitude higher than standard CdCl{sub 2}-treated devices, without compromising the lifetime.},
doi = {10.1063/1.4954904},
journal = {Applied Physics Letters},
number = 26,
volume = 108,
place = {United States},
year = {Mon Jun 27 00:00:00 EDT 2016},
month = {Mon Jun 27 00:00:00 EDT 2016}
}