Preparation and characterization of copper indium disulfide films by facile chemical method

A convenient and low cost technology was employed to prepare copper indium disulfide thin films, which can be analogous to other chalcogenides. The designed precursor solutions with Cu/In ratio at 1.5:1, 1:1, and 1:1.5, respectively, were prepared and coated on the glass substrate by dip-withdrawing method. The thin films were characterized by XRD, SEM, UV–Vis–NIR spectrophotometer, NKD-7000W spectrophotometer, Raman microscope and wavelength dispersive XRF spectrometer. As a result, chalcopyrite-type CuInS2 is the dominant phase in final products. CuxS is also obtained as a minor phase composition. The as-prepared CuInS2 films are of high absorption coefficient of 2.65 × 105 cm−1 at 400 nm and 1.7 × 105 cm−1 at 600 nm. The calculated band gap values are 1.28–1.62 eV, according with the theoretical band gap of CuInS2.