Premium
Defects in Cu(In, Ga) Se 2 semiconductors and their role in the device performance of thin‐film solar cells
Author(s) -
Burgelman M.,
Engelhardt F.,
Guillemoles J. F.,
Herberholz R.,
Igalson M.,
Klenk R.,
Lampert M.,
Meyer T.,
Nadenau V.,
Niemegeers A.,
Parisi J.,
Rau U.,
Schock H. W.,
Schmitt M.,
Seifert O.,
Walter T.,
Zott S.
Publication year - 1997
Publication title -
progress in photovoltaics: research and applications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.286
H-Index - 131
eISSN - 1099-159X
pISSN - 1062-7995
DOI - 10.1002/(sici)1099-159x(199703/04)5:2<121::aid-pip159>3.0.co;2-4
Subject(s) - chalcopyrite , thin film , materials science , semiconductor , photoluminescence , solar cell , copper indium gallium selenide solar cells , spectroscopy , band gap , optoelectronics , impurity , acceptor , characterization (materials science) , crystallographic defect , analytical chemistry (journal) , condensed matter physics , copper , chemistry , nanotechnology , physics , metallurgy , organic chemistry , quantum mechanics , chromatography
This contribution is a summary of an international, interdisciplinary workshop dedicated to defects in chalcopyrite semiconductors and their relation to the device characteristics of thin‐film solar cells, held on 3–5 June 1996 in Oberstdorf, Germany. Results of different characterization methods were brought together to identify common observations. The comparison of results from electrical defect spectroscopy and luminescence investigations confirmed the presence of energetic distributions of defects throughout the bandgap of chalcopyrite thin films. Electrical defect spectroscopy detects a defect about 280 meV above the valence band edge of Cu(In, Ga)Se 2 regardless of the preparation conditions of the sample. In a solar cell the density of this defect depends on the operation conditions. This observation might be related to the migration of copper in an electric field, which occurs even at room temperature. Other defects appear to be related to processing or impurities. Photoluminescence decay measurements yield time constants of several nanoseconds under low injection conditions. Modelling of the current–voltage characteristics of Cu(In, Ga)Se 2 ‐based thin‐film cells suggests that compensating acceptor states in the CdS or at the heterointerface are responsible for the frequently observed cross‐overs between the dark and illuminated curves.© 1997 John Wiley & Sons, Ltd.