Abstract: CuInS2 (CIS) thin films with sufficient sulfur content and good morphology are hard to be grown by the present electrodeposition technique. In order to deal with the problem, CuInS precursor thin films are prepared on ITO glass by the onestep electrodeposition technique in the electrolyte with SiO2 sol. The electrolytic bath used for the preparation of the thin films consists of metal salts, sodium thiosulfate (〖JP2〗Na2S2O3〖JP〗) and various concentrations of SiO2 sol. Then the CuInS precursor thin films are annealed in airatmosphere to ensure adequate crystallization of the CuInS2 thin films. Samples are characterized using Xray diffraction(XRD), scanning electron microscopy(SEM),energy dipersive spectroscopy(EDS) and open potential. It is found that films with higher crystallinity are achieved when the concentration of SiO2 sol is 4 mL/L. Besides, the morphology, composition, and photoresponse performance are improved by adding SiO2 sol in the electrolyte. The result of the investigation indicates that the performance of the CIS thin films can be improved by adding SiO2 sol in the electrolyte, especially when the concentration of the SiO2 is 4 mL/L.

Key words: thin films, CuInS2, SiO2 sol, electrodeposition, photoresponse performance