Characterization of CuInS2 thin films prepared by one-step DC reactive sputtering

CuInS₂ thin films have been prepared by one-step DC reactive sputtering process. Full characterizations have been carried out by EDS, XRD, SEM, optical transmittance and electrical measurement. XRD and SEM analysis of the films show that the crystallinity and morphology could be improved by altering the composition of the films to stoichiometric. The band gaps of samples with different Cu/In ratio are in range of 1.45~1.47 eV, and the absorption coefficient of all films are about 10⁵ cm^-1. As the increasing of the Cu/In ratio, the mobility of the carriers increases slightly, while the resistivity decrease and mobility increases sharply when the Cu/In ratio approach to 1.0.