Substrate Rotation Chemical Bath Deposition of Cadmium Sulfide Buffer Layers for Thin Film Solar Cell Application

Abstract

A method for deposition of cadmium sulfide (CdS) buffer layer thin films on fluorine-doped tin oxide (FTO) glass, by chemical bath deposition (CBD), has been modified. For achieving relatively uniform and pin-hole-free CdS films, substrate rotation, concentration of CdS salts, and deposition time were optimized. The deposited films were characterized by UV-Vis-NIR spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscopy (AFM). Band gap of ~ 2.4 eV was measured by UV-Vis-NIR spectroscopy, CdS phase was confirmed by XRD, and film uniformity and roughness ( ~ 15–20 nm) were measured by SEM and AFM, respectively.