Electrical properties of chemically prepared nonstoichiometric CuIn(S,Se) sub(2) thin films

Polycrystalline thin films of copper indium sulphoselenide [CuIn(S,Se) sub(2)] were deposited on glass substrate by chemical bath deposition technique. The deposition parameters such as pH, temperature and time were optimized. A set of films having different elemental compositions was prepared by varying Cu/In ratio from 1.87-12.15. The films were characterized by X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDAX). The chemical composition of the CuIn(S,Se) sub(2) was found to be nonstoichiometric. The d.c. conductivities of the films were studied below and near room temperature. The thermo-electric power of the films was also measured and type of semiconductivity was ascertained.