The present work reports high power conversion efficiency quantum dot sensitized solar cells (QDSSCs) based on Ca-doped CuS counter electrodes (CEs) with TiO₂/CdS/CdSe/ZnS photoanodes and a polysulfide electrolyte. Ca-doped CuS thin film was prepared on fluorinedoped tin oxide (FTO) glass surfaces via widely adopted chemical bath deposition (CBD) method. The surface studies of Ca-doped CuS CEs shows that the particles are uniformly distributed with high crystal linity structure. EDAX analysis results indicates that Cu, S, and Ca ions successfully deposited on the surface of FTO plate. All the experimental results indicate that 20% Ca-doped CuS CE based QDSSCs exhibit high power conversion efficiency (η) of 4.92%.