CuInS2 thin films obtained by solid-state sulfurization

CuInS2 thin films were prepared by sulfurization of Cu–In precursor films through magnetron sputtering. The obtained films were characterized using X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), UV–vis spectrophotometer and Hall Effect measurement. The results showed that the precursors films obtained at a sputtering power of 15 W were more dense and smooth. The CuInS2 thin films sulfurized at 450 °C for 20 min demonstrated a typical chalcopyrite structure, with preferred orientation along the (112) plane and possessing 1.48 eV direct band gap. The study also illustrated that the composition of thin films almost kept stable while the film formation conditions changed, like sulfurization temperature and time, etc. The value of the direct band gap would increase with sulfurization temperature heating up.