Growth and characterization of CuxS (x=1.0, 1.76, and 2.0) thin films grown by solution growth technique (SGT)

Thin films of Cu_xS (x=1.0, 1.76, and 2.0) were grown by solution growth technique (SGT). The deposition parameters such as pH of solution, deposition time, and deposition temperature were optimized. The deposited films were annealed in Ar atmosphere at 250 °C. The changes in structural and optical transport phenomenon of annealed films have been studied. The surface morphology and composition of films were studied by SEM micrographs and EDAX analysis, respectively, and the surface roughness was calculated by atomic force microscopy (AFM). The XRD study showed the polycrystalline nature of annealed film. The lattice parameters of different phases of the material were calculated from the XRD pattern. The absorption coefficient varies in the range of 1×10⁵-6×10⁵ cm⁻¹. The optical bandgaps of CuS, Cu_1.76S, and Cu₂S are 1.72, 2.11, and 2.48 eV, respectively.