Formation of CuInSe2 by the selenization of sputtered Cu/In layers

Single layers of Cu and In were deposited onto Mo coated glass substrates by radio frequency sputtering. The Cu11In9 phase has been found to be the majority phase in these precursors. The selenization of the sputtered layers has been achieved by depositing a 1 mu m Se layer onto the precursor by thermal evaporation followed by an annealing in vacuum. Samples were annealed at different temperatures varying between 100-600 degrees C at intervals of 50 degrees C. The chalcopyrite structured ternary phase of CulnSe(2) with a significant amount of preferential orientation in the (112) direction was obtained in samples annealed at 400 degrees C or above. Morphological, compositional and structural analyses of the samples annealed at different temperatures were performed using a variety of complementary techniques. The results were analysed to explain the growth of CulnSe(2) on the selenization of sputtered Cu-ln precursors. The occurrence of various binary phases of Cu-ln, Cu-Se and In-Se in different annealing temperature ranges has also been investigated. The phenomenon of volume expansion in CulnSe(2) on selenization has been found to manifest itself as a shift in the characteristic (110) X-ray diffraction peak of Mo.