Effect of sulfurization temperature on the properties of CuIn(S,Se)2 thin films fabricated from electrodeposited CuInSe2 precursors

This paper reports the analysis of S diffusion into electrodeposited CuInSe2 (CISe) precursors during post-sulfurization treatment at different sulfurization temperatures. The morphology, composition, structure and optical properties of CuIn(S,Se)2(CISSe) films were characterized by SEM, EDS, XRD, Raman scattering and UV-Vis-NIR spectrophotometer. It was found that high sulfurization temperatures can facilitate the incorporation of sulfur into the precursor film and improve the crystalline properties of the sulfurized films. The best sample is the one prepared by sulfurization at 500 °C.Itexhibitsrelatively homogeneous CuIn(SxSe1-x)2 phase structure. In addition, we observed a sulfur concentration difference between top part and bottom part of the sulfurized films. All these films exhibit high transmission and their optical band gapsincrease with the increase of annealing temperature.