Indium doping on the structural, surface and optical properties of CdS thin films prepared by ultrasonic spray pyrolysis method

CdS nanostructures are important and useful materials for photovoltaic applications. In this paper, pure CdS and In doped CdS (CdS:In) thin films were fabricated on soda lime glass substrate using ultrasonic spray pyrolysis (USP) method, to investigate the effect In concentration on the structural behavior, surface and optical properties of the CdS thin films by X-ray diffraction (XRD), Atomic Force Microscopy (AFM) and Ultraviolet–visible (Uv-vis) spectrophotometry. X-ray diffraction patterns of the pure and In doped CdS films indicated that pure CdS film had a mixed of cubic and hexagonal structure with polycrystalline nature while In doped CdS had a hexagonal structure with polycrystalline nature. Increasing the In doping ratio improve the (002) preferential orientation. The optical properties of the In-doped CdS and pure CdS films showed that the energy band gap of the In-doped CdS is a slightly lower than the energy band gap of the pure CdS film. The surface properties of the films showed that all thin films are compact and uniform.