Characterization of Cu(In,Ga) (S,Se)2thin films prepared by sequential evaporation from ternary compounds

Abstract

Cu(In,Ga) (S,Se)2 thin films were fabricated by sequential evaporation from CuGaSe2, CuInSe2 and In2S3 compounds for photovoltaic device applications. From XRF analysis, the Cu:(In + Ga):(S + Se) atomic ratio in all thin films was approximately 1:1:2. As the [In2S3]/([CuGaSe2] + [CuInSe2]) mole ratio in the evaporating materials increased, the S/(S + Se) atomic ratio in the thin films increased from 0 to 0.16 determined by XRF and to 0.43 by EPMA. XRD studies demonstrated that the prepared thin films had a chalcopyrite Cu(In,Ga) (S,Se)2 structure and the preferred orientation to the 112 plane. The SEM images demonstrated that Cu(In,Ga) (S,Se)2 thin films had large and columnar grains. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)