CuInS2 films using repeated chemical spray pyrolysis

CuInS2 films of thickness 1.17 mum were deposited onto glass substrates using repeated spraying technique without any pinholes on the samples. It has been shown that the structure, optical and electrical properties depend on the [Cu]/[In] ratio taken in the solution. Studies using X-ray Diffraction, X-ray Photoelectron Spectroscopy (XPS), Energy Dispersive X-ray Analysis (EDX), optical absorption, photosensitivity and conductivity measurements proved this. Moreover, XPS depth-profiling revealed that there is no oxygen present in the bulk of the film; even though it was prepared using repeated spraying. Oxygen was present only in few atomic layers at the surface of the film and near the substrate-film interface. Use of Cu-rich initial solution resulted in better crystallinity as well as conductivity. EDX measurements showed that [Cu]/[In] ratio in the film is slightly less than that taken in the solution. Photosensitivity of the samples decreased with increase in [Cu]/[In] ratio. (C) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.