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

Title: Optically induced metastability in Cu(In,Ga)Se 2

Abstract

Cu(In,Ga)Se 2 (CIGS) is presently the most efficient thin-film photovoltaic technology with efficiencies exceeding 22%. An important factor impacting the efficiency is metastability, where material changes occur over timescales of up to weeks during light exposure. A previously proposed (V Se -V Cu ) divacancy model presents a widely accepted explanation. We present experimental evidence for the optically induced metastability transition and expand the divacancy model with first-principles calculations. Using photoluminescence excitation spectroscopy, we identify a sub-bandgap optical transition that severely deteriorates the carrier lifetime. This is in accordance with the expanded divacancy model, which predicts that states below the conduction band are responsible for the metastability change. We determine the density–capture cross-section product of the induced lifetime-limiting states and evaluate their impact on device performance. The experimental and theoretical findings presented can allow assessment of metastability characteristics of leading thin-film photovoltaic technologies.

Authors:
 [1];  [1]; ORCiD logo [1];  [1]; ORCiD logo [1];  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
OSTI Identifier:
1407457
Report Number(s):
NREL/JA-5900-67677
Journal ID: ISSN 2045-2322
Grant/Contract Number:  
AC36-08GO28308
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 7; Journal ID: ISSN 2045-2322
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; photovoltaics; thin films; efficiency; metastability; solar cells

Citation Formats

Jensen, S. A., Kanevce, A., Mansfield, L. M., Glynn, S., Lany, S., and Kuciauskas, D. Optically induced metastability in Cu(In,Ga)Se2. United States: N. p., 2017. Web. doi:10.1038/s41598-017-14344-6.
Jensen, S. A., Kanevce, A., Mansfield, L. M., Glynn, S., Lany, S., & Kuciauskas, D. Optically induced metastability in Cu(In,Ga)Se2. United States. doi:10.1038/s41598-017-14344-6.
Jensen, S. A., Kanevce, A., Mansfield, L. M., Glynn, S., Lany, S., and Kuciauskas, D. Mon . "Optically induced metastability in Cu(In,Ga)Se2". United States. doi:10.1038/s41598-017-14344-6. https://www.osti.gov/servlets/purl/1407457.
@article{osti_1407457,
title = {Optically induced metastability in Cu(In,Ga)Se2},
author = {Jensen, S. A. and Kanevce, A. and Mansfield, L. M. and Glynn, S. and Lany, S. and Kuciauskas, D.},
abstractNote = {Cu(In,Ga)Se2 (CIGS) is presently the most efficient thin-film photovoltaic technology with efficiencies exceeding 22%. An important factor impacting the efficiency is metastability, where material changes occur over timescales of up to weeks during light exposure. A previously proposed (V Se -V Cu ) divacancy model presents a widely accepted explanation. We present experimental evidence for the optically induced metastability transition and expand the divacancy model with first-principles calculations. Using photoluminescence excitation spectroscopy, we identify a sub-bandgap optical transition that severely deteriorates the carrier lifetime. This is in accordance with the expanded divacancy model, which predicts that states below the conduction band are responsible for the metastability change. We determine the density–capture cross-section product of the induced lifetime-limiting states and evaluate their impact on device performance. The experimental and theoretical findings presented can allow assessment of metastability characteristics of leading thin-film photovoltaic technologies.},
doi = {10.1038/s41598-017-14344-6},
journal = {Scientific Reports},
issn = {2045-2322},
number = ,
volume = 7,
place = {United States},
year = {2017},
month = {10}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 3 works
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

Time dependent voltage in CuInSe/sub 2/ and CdTe solar cells
conference, January 1993

  • Sasala, R. A.; Sites, J. R.
  • Conference Record of the Twenty Third IEEE Photovoltaic Specialists Conference - 1993 (Cat. No.93CH3283-9)
  • DOI: 10.1109/PVSC.1993.347036

Optical functions of chalcopyrite CuGaxIn1-xSe2 alloys
journal, May 2002

  • Alonso, M. I.; Garriga, M.; Durante Rincón, C. A.
  • Applied Physics A: Materials Science & Processing, Vol. 74, Issue 5, p. 659-664
  • DOI: 10.1007/s003390100931

Investigation of long lifetimes in Cu(In,Ga)Se 2 by time-resolved photoluminescence
journal, September 2015

  • Maiberg, Matthias; Hölscher, Torsten; Zahedi-Azad, Setareh
  • Applied Physics Letters, Vol. 107, Issue 12
  • DOI: 10.1063/1.4931632

Solar cell efficiency tables (version 48): Solar cell efficiency tables (version 48)
journal, June 2016

  • Green, Martin A.; Emery, Keith; Hishikawa, Yoshihiro
  • Progress in Photovoltaics: Research and Applications, Vol. 24, Issue 7
  • DOI: 10.1002/pip.2788

Electronic properties of Cu(In,Ga)Se 2 heterojunction solar cells-recent achievements, current understanding, and future challenges
journal, August 1999

  • Rau, U.; Schock, H. W.
  • Applied Physics A: Materials Science & Processing, Vol. 69, Issue 2
  • DOI: 10.1007/s003390050984

Distinguishing metastable changes in bulk CIGS defect densities from interface effects
journal, May 2003


The electronic structure of chalcopyrites-bands, point defects and grain boundaries
journal, August 2010

  • Siebentritt, Susanne; Igalson, Malgorzata; Persson, Clas
  • Progress in Photovoltaics: Research and Applications, Vol. 18, Issue 6
  • DOI: 10.1002/pip.936

Na incorporation into Cu(In,Ga)Se2 for high-efficiency flexible solar cells on polymer foils
journal, April 2005

  • Rudmann, D.; Brémaud, D.; Zogg, H.
  • Journal of Applied Physics, Vol. 97, Issue 8
  • DOI: 10.1063/1.1857059

From ultrasoft pseudopotentials to the projector augmented-wave method
journal, January 1999


Fiber-fed time-resolved photoluminescence for reduced process feedback time on thin-film photovoltaics
journal, January 2015

  • Repins, I. L.; Egaas, B.; Mansfield, L. M.
  • Review of Scientific Instruments, Vol. 86, Issue 1
  • DOI: 10.1063/1.4905535

Effect of Ga content on defect states in CuIn 1−x Ga x Se 2 photovoltaic devices
journal, June 2002

  • Heath, J. T.; Cohen, J. D.; Shafarman, W. N.
  • Applied Physics Letters, Vol. 80, Issue 24
  • DOI: 10.1063/1.1485301

Progress toward 20% efficiency in Cu(In,Ga)Se2 polycrystalline thin-film solar cells
journal, July 1999


Band-structure calculations for the 3 d transition metal oxides in G W
journal, February 2013


Effects of heavy alkali elements in Cu(In,Ga)Se 2 solar cells with efficiencies up to 22.6%
journal, July 2016

  • Jackson, Philip; Wuerz, Roland; Hariskos, Dimitrios
  • physica status solidi (RRL) - Rapid Research Letters, Vol. 10, Issue 8
  • DOI: 10.1002/pssr.201600199

Light- and bias-induced metastabilities in Cu(In,Ga)Se[sub 2] based solar cells caused by the (V[sub Se]-V[sub Cu]) vacancy complex
journal, January 2006

  • Lany, Stephan; Zunger, Alex
  • Journal of Applied Physics, Vol. 100, Issue 11
  • DOI: 10.1063/1.2388256

A recombination analysis of Cu(In,Ga)Se2 solar cells with low and high Ga compositions
journal, May 2014

  • Li, Jian V.; Grover, Sachit; Contreras, Miguel A.
  • Solar Energy Materials and Solar Cells, Vol. 124, p. 143-149
  • DOI: 10.1016/j.solmat.2014.01.047

Optoelectronic Investigation of Sb-Doped Cu(In,Ga)Se 2
journal, November 2015

  • Mansfield, Lorelle M.; Kuciauskas, Darius; Dippo, Patricia
  • IEEE Journal of Photovoltaics, Vol. 5, Issue 6
  • DOI: 10.1109/JPHOTOV.2015.2470082

Persistent photoconductivity in Cu(In,Ga)Se2 heterojunctions and thin films prepared by sequential deposition
journal, July 1998

  • Rau, U.; Schmitt, M.; Parisi, J.
  • Applied Physics Letters, Vol. 73, Issue 2
  • DOI: 10.1063/1.121762

A model for the open circuit voltage relaxation in Cu(In,Ga)Se 2 heterojunction solar cells
journal, October 1999

  • Meyer, Th.; Schmidt, M.; Engelhardt, F.
  • The European Physical Journal Applied Physics, Vol. 8, Issue 1
  • DOI: 10.1051/epjap:1999228

Investigation of deep-level defects in Cu(In,Ga)Se 2 thin films by a steady-state photocapacitance method
journal, October 2014

  • Hu, Xiaobo; Sakurai, Takeaki; Yamada, Akimasa
  • Journal of Applied Physics, Vol. 116, Issue 16
  • DOI: 10.1063/1.4899321

Anisotropic hole-mass tensor of CuIn1−xGax(S,Se)2: Presence of free carriers narrows the energy gap
journal, August 2008


Photoconductivity of p-type CuInSe2
journal, October 1993


Optimization of CBD CdS process in high-efficiency Cu(In,Ga)Se2-based solar cells
journal, February 2002


Many-body G W calculation of the oxygen vacancy in ZnO
journal, March 2010


Effect of light soaking on the electro- and photoluminescence of Cu(In,Ga)Se 2 solar cells
journal, October 2013

  • Müller, T. C. M.; Tran, T. M. H.; Pieters, B. E.
  • Applied Physics Letters, Vol. 103, Issue 18
  • DOI: 10.1063/1.4827260

Long lifetimes in high-efficiency Cu(In,Ga)Se2 solar cells
journal, July 2008

  • Metzger, Wyatt K.; Repins, Ingrid L.; Contreras, Miguel A.
  • Applied Physics Letters, Vol. 93, Issue 2
  • DOI: 10.1063/1.2957983

Intrinsic point defects in CuInSe 2 and CuGaSe 2 as seen via screened-exchange hybrid density functional theory
journal, June 2013


Implementation and performance of the frequency-dependent G W method within the PAW framework
journal, July 2006


Bulk and metastable defects in CuIn1−xGaxSe2 thin films using drive-level capacitance profiling
journal, February 2004

  • Heath, Jennifer T.; Cohen, J. David; Shafarman, William N.
  • Journal of Applied Physics, Vol. 95, Issue 3
  • DOI: 10.1063/1.1633982

Beneficial effect of post-deposition treatment in high-efficiency Cu(In,Ga)Se2 solar cells through reduced potential fluctuations
journal, August 2016

  • Jensen, S. A.; Glynn, S.; Kanevce, A.
  • Journal of Applied Physics, Vol. 120, Issue 6
  • DOI: 10.1063/1.4960344

Optical-fiber-based, time-resolved photoluminescence spectrometer for thin-film absorber characterization and analysis of TRPL data for CdS/CdTe interface
conference, June 2012

  • Kuciauskas, Darius; Duenow, Joel N.; Kanevce, Ana
  • 2012 IEEE 38th Photovoltaic Specialists Conference (PVSC), 2012 38th IEEE Photovoltaic Specialists Conference
  • DOI: 10.1109/PVSC.2012.6317927

    Works referencing / citing this record:

    Large metastability in Cu (In,Ga)Se 2 devices: The importance of buffer properties
    journal, June 2019

    • Repins, Ingrid; Glynn, Stephen; Silverman, Timothy J.
    • Progress in Photovoltaics: Research and Applications, Vol. 27, Issue 9
    • DOI: 10.1002/pip.3145

    Large metastability in Cu (In,Ga)Se 2 devices: The importance of buffer properties
    journal, June 2019

    • Repins, Ingrid; Glynn, Stephen; Silverman, Timothy J.
    • Progress in Photovoltaics: Research and Applications, Vol. 27, Issue 9
    • DOI: 10.1002/pip.3145