CuInS₂ ternary films is a promising absorber material for thin film solar cells. It has recently attracted considerable attention due to its high photovoltaic conversion efficiency, and the opportunity to be synthesized by low-cost techniques. In this work CuInS₂ thin films have been deposited by chemical Spray pyrolysis onto glass substrate at ambient atmosphere without sulfurization.

The effect of the [Cu]/[In] ration, substrate temperature and the time of spray, on the structural, chemical stoichiometry, topographical, and optical properties of CIS thin films were investigated. EDS result demonstrated that stoichiometric CuInS₂ film can be adjusted [Cu]/[In] ration. Chalcopyrite structure of this film was confirmed by XRD analysis. The near stoichiometric CuInS₂ film has the optical band gap Eg of 1.45eV.