Size-dependent photovoltaic performance of cadmium sulfide (CdS) quantum dots for solar cell applications

CdS quantum dots (QDs) with different size ranging from 3.05 to 9.07 nm were successfully deposited on spin coated mesoporous TiO2 (Degussa-P25) nanostructures by successive ionic layer adsorption and reaction (SILAR) method by varying the deposition cycle (CdS 9, 12, 15 and 18 SILAR cycles). The structural, morphological and optical properties were tested for the prepared TiO2/CdS QDs. The highest optical absorption in the visible region range of 550 nm was observed for 15 cycles CdS QDs deposited by SILAR method. Under illumination of 100 mW/cm2, the maximum photovoltaic conversion efficiency of 1.8% was obtained for 15 cycles deposited CdS QDs by SILAR method. The corresponding photovoltaic parameters such as short circuit current density (Jsc), open circuit voltage (Voc) and fill factor (FF) were 3.81 mA/cm2, 0.76 V and 61.9% respectively.