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

Title: The hunt for the third acceptor in CuInSe2 and Cu(In,Ga)Se2 absorber layers

Journal Article · · Journal of Physics. Condensed Matter

We show the model for intrinsic defects in Cu(In,Ga)Se2 semiconductor layers is still under debate for the full range between CuInSe2 and CuGaSe2. It is commonly agreed by theory and experiment, that there are at least one shallow donor and two shallow acceptors. Spatially resolved photoluminescence on CuGaSe2 previously revealed a third acceptor. In this study we show with the same method that the photoluminescence peak at 0.94 eV in CuInSe2, previously attributed to a third acceptor, is a phonon replica. However another pronounced peak at 0.9 eV is detected on polycrystalline CuInSe2 samples grown with high copper and selenium excess. Intensity and temperature dependent photoluminescence measurements reveal that this peak originates from a DA-transition from a shallow donor (<8 meV) into a shallow acceptor A3 (135 [Formula: see text] 10) meV. The DA3 transition has three distinct phonon replicas with 28 meV spectral spacing and a Huang Rhys factor of 0.75. Complementary admittance measurements are dominated by one main step with an activation energy of 125 meV which corresponds well with the found A3 defect. The same defect is also observed in Cu(In,Ga)Se2 samples with low gallium content. For [Ga]/([Ga] + [In])-ratios of up to 0.15 both methods show a concordant increase of the activation energy with increasing gallium content shifting the defect deeper into the bandgap. The indium vacancy νIn is discussed as a possible origin of the third acceptor level in CuInSe2 and νIII in Cu(In,Ga)Se2.

Research Organization:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Science (SC)
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
1582339
Journal Information:
Journal of Physics. Condensed Matter, Vol. 31, Issue 42; ISSN 0953-8984
Publisher:
IOP PublishingCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 13 works
Citation information provided by
Web of Science

References (43)

Why are kesterite solar cells not 20% efficient? journal May 2013
Acceptor activation energies in epitaxial CuGaSe2 grown by MOVPE journal May 2001
Radiative recombination in melt‐grown and Cd‐implanted CuInSe 2 journal February 1976
High‐efficiency CuIn x Ga 1− x Se 2 solar cells made from (In x ,Ga 1− x ) 2 Se 3 precursor films journal July 1994
Photoluminescence studies of CuInSe2: Identification of intrinsic defect levels journal August 1984
Characterization of CuIn(Ga)Se2 Thin Films journal July 1998
MOVPE of CuGaSe2 on GaAs in the presence of a CuxSe secondary phase journal January 2011
Do we really need another PL study of CuInSe2? journal August 2004
Self-compensation of intrinsic defects in the ternary semiconductor CuGaSe 2 journal January 2004
Reconciliation of luminescence and Hall measurements on the ternary semiconductor CuGaSe2 journal February 2005
Influence of secondary phase CuxSe on the optoelectronic quality of chalcopyrite thin films journal May 2011
Radiative recombination via intrinsic defects in CuxGaySe2 journal April 2001
Optical properties and characterization of CuInSe2 journal January 1986
Magneto-photoluminescence study of radiative recombination in CuInSe2 single crystals journal September 2003
First-Principles Modeling of Point Defects and Complexes in Thin-Film Solar-Cell Absorber CuInSe 2 journal February 2017
Interference effects in photoluminescence spectra of Cu 2 ZnSnS 4 and Cu(In,Ga)Se 2 thin films journal July 2015
Cu(In,Ga)Se 2 solar cells with improved current based on surface treated stoichiometric absorbers: Cu(In,Ga)Se 2 solar cells with improved current journal September 2016
Defect level identification in copper indium selenide (CuInSe2) from photoluminescence studies journal May 1990
Tutorial: Defects in semiconductors—Combining experiment and theory journal May 2016
Vaporization studies on elemental tellurium and selenium by Knudsen effusion mass spectrometry journal August 2014
Effects of heavy alkali elements in Cu(In,Ga)Se 2 solar cells with efficiencies up to 22.6% journal July 2016
Why do we make Cu(In,Ga)Se2 solar cells non-stoichiometric? journal December 2013
Deep recombination centers in C u 2 ZnSnS e 4 revealed by screened-exchange hybrid density functional theory journal November 2015
Potassium fluoride postdeposition treatment with etching step on both Cu-rich and Cu-poor CuInS e 2 thin film solar cells journal October 2018
Radiative recombination and shallow centers in CuInSe 2 journal August 1984
Challenge in Cu-rich CuInSe 2 thin film solar cells: Defect caused by etching journal May 2019
Correcting for interference effects in the photoluminescence of Cu(In,Ga)Se2 thin films journal February 2017
Revisiting radiative deep-level transitions in CuGaSe 2 by photoluminescence journal July 2016
Sharp Optical Emission from $\bf CuInSe_{2}$ Thin Films Grown by Molecular Beam Epitaxy journal April 1994
Vapour composition and critical constants of selenium journal June 1974
Native point defects in CuIn 1−x Ga x Se 2 : hybrid density functional calculations predict the origin of p- and n-type conductivity journal January 2014
Effects of heavy alkali elements in Cu(In,Ga)Se2 solar cells with efficiencies up to 22.6% text January 2016
Excitonic luminescence of Cu(In,Ga)Se2 journal June 2005
Local fluctuations of absorber properties of Cu(In,Ga)Se2 by sub-micron resolved PL towards “real life” conditions journal February 2009
Defect levels in the epitaxial and polycrystalline CuGaSe 2 by photocurrent and capacitance methods journal November 2011
Formation, migration, and clustering of point defects in CuInSe 2 from first principles journal August 2014
Intrinsic point defects in CuInSe 2 and CuGaSe 2 as seen via screened-exchange hybrid density functional theory journal June 2013
Photoluminescence of a High Quality CuInSe2 Single Crystal journal March 1998
Free and bound exciton emission in CuInSe2 and CuGaSe2 single crystals journal June 1998
Electronic defects in Cu ( In , Ga ) S e 2 : Towards a comprehensive model journal September 2019
Silicon Wafer Orientation Dependence of Metal Oxide Semiconductor Device Reliability journal January 1994
Characterization of CuIn(Ga)Se2 Thin Films journal May 1998
Native point defects in CuIn$_{1-x}$Ga$_x$Se$_{2}$: hybrid density functional calculations predict origin of p- and n-type conductivity text January 2014