TY - JOUR N2 - Thin film solar cells based on multinary compound Cu(In,Ga)Se2 show record photovoltaic conversion efficiency approaching 20%. Investigation on defect physics in this compound is crucial for making further progress in the technology. In this work we present the results on photocapacitance (PC) and deep level optical spectroscopy (DLOS) for two types of cells – high efficiency Cu(In,Ga)Se2 cell with about 20% of gallium and pure gallium CuGaSe2 device. We show that PC and DLOS, employed as the techniques complimentary to deep level transient spectroscopy DLTS and admittance spectroscopy, are useful methods in providing information on defect levels in solar cells. In particular they are helpful in diffierentiating between levels belonging to the bulk of absorber and to the interface states. We tentatively assign some of the observed deep levels to InCu or GaCu antisites and Cu interstitials. L1 - http://www.journals.pan.pl/Content/111763/PDF-MASTER/(53-2)157.pdf L2 - http://www.journals.pan.pl/Content/111763 PY - 2005 IS - No 2 EP - 161 KW - solar cells KW - CIGS KW - photocapacitance KW - deep levels A1 - Igalson, M. A1 - Urbaniak, A. VL - vol. 53 DA - 2005 T1 - Defect states in the CIGS solar cells by photocapacitance and deep level optical spectroscopy SP - 157 UR - http://www.journals.pan.pl/dlibra/publication/edition/111763 T2 - Bulletin of the Polish Academy of Sciences Technical Sciences ER -