Effect of Lithium on Structural and Optical Properties of Nanostructured CuS Thin Films

In this study, the chemical bath deposition (CBD) strategy was applied for preparation of pure and Lithium-doped copper sulfide (CuS) thin film on glass. The CuCl2.2H2O, as a copper source and thiourea as a sulfur source were used. The structural, topographical, and optical properties of products were characterized via powder X-ray diffraction (XRD), atomic force microscopy (AFM), and UV-Vis spectroscopy. Results showed that the crystalline size is increased via Lithium doping, though the strain (%) parameter decrease from 30.39 to 27.47. Obtained results revealed that doing of lithium has a significant effect on the optical properties of prepared CuS-based thin films. The optical properties of samples was investigated through band gap calculation. The bands gap were calculated 2.4, 2.5, and 2.6 eV for CuS:3% Li, CuS:1% Li and pure CuS thin films respectively. Based on attractive properties of prepared thin films, Lithium-doped CuS thin film has potential application in optoelectronic fields.