Characterization of CuInS 2 thin films prepared by sulfurization of Cu-In precursor

Abstract

CuInS 2 thin films were prepared by sulfurization of Cu-In precursors. The influences of the deposition sequence of Cu and In layers, such as Cu/In, Cu/In/In, and In/Cu/In, on structure, topography, and optical properties of CuInS 2 thin films were investigated. X-ray diffraction results show that the deposition sequence of Cu and In layers affects the crystalline quality of CuInS 2 films. Atomic force microstructure images reveal that the grain size and surface roughness are related to the deposition sequence used. When the deposition sequence of precursor is In/Cu/In, the CuInS 2 thin films show a single-phase chalcopyrite structure with (112) preferred orientation. The surface morphology of CIS films is uniform and compacted. The absorption coefficient is larger than 10 4 cm −1 with optical band gap E g close to 1.4 eV.