Preliminary Study of Effective Copper Indium Sulfide (CuInS2) Quantum Dots as Photo-sensitizer in Solar Cell

Recent studies showed that quantum dots (QDs) materials such as cadmium (Cd) and lead (Pb) are commonly used as sensitizer in solar cell applications. This is mainly because they have high potential in light harvesting. However, these materials are highly toxicity and very harmful to the environment. Therefore, current investigation reports the performance of quantum dots sensitized solar cells (QDSSCs) based on non-toxicity CuInS₂ QDs by using solvothermal process. TiO₂ paste were deposited by doctor blade method on transparent conducting fluorine doped tin oxide (FTO) glass substrates. The CuInS₂ nano sized QDs were controlled by different solvothermal reaction times of 2 hours, 4 hours, 6 hours and 8 hours. In this study, the morphology, structural and optical properties of prepared TiO₂/CuInS₂ QDs thin films were investigated by using Transmission Electron Microscope (TEM), Atomic Force Microscope (AFM), X-ray Diffraction (XRD) and Ultra-Violet-Visible Near Infrared Spectrophotometer (UV-Vis). The diameter of CuInS₂ QDs was found to be increased from 3.19 nm to 8.67 nm with longer reaction time. Results showed that CuInS₂ QDs with longer reaction time produced higher conversion efficiency. Based on the experiment done, CuInS₂ QDs with 8 hours reaction time produced the best power conversion efficiency; 0.035 %. Regarding the considerable efficiencies obtained, pointed out that CuInS₂ QDs can be introduced as an effective photosensitizer for making efficient QDSSCs devices.