A one pot hydrothermal stimulated CdS-reduced graphene oxide (CdS/rGO) hybrid nanocomposite for high performance photovoltaic applications

The development of high performance and cost-effective counter electrode (CE) is a persistent objective in order to convey the quantum dot sensitized solar cell (QDSSC) from laboratories to markets benches. In this study, we fabricate a novel CdS/reduced graphene oxide hybrid composite by a one step hydrothermal method using cadmium nitrate, thiourea and graphite as raw materials. Prior to the photovoltaic study the structural, morphological and optical properties of the samples were analyzed by using X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Raman, UV–Vis diffuse reflectance spectra (DRS) and Photoluminescence spectra analysis. XRD and FESEM results exhibit that cubic structure with spherical shaped morphology of CdS and particles are well dispersed on the graphene nanosheets. The surface area and pore size of CdS/rGO composite was analyzed by using N₂ absorption–desorption measurements and found to be 127 m²/g and 13.51 nm respectively, which is higher than that of bare CdS (73 m²/g; 28.23 nm). We further construct the flexible photoelectrodes bys using CdS and rGO and studied the photovoltaic performance. Photovoltaic parameters, such as short-circuit photocurrent density, open circuit voltage, fill factor and conversion efficiency were found to be 9.7 mA/cm², 0.91 V, 68.0% and 12.5% respectively, for CdS/rGO photoelectrode.