THE INVESTIGATION OF OPTICAL PROPERTIES, STRUCTURAL PROPERTIES AND INFLUENCE OF THERMAL ANNEALING ON SEMICONDUCTING OXIDES IN QUANTUM DOT SENSITIZED SOLAR CELLS

This research investigates the optical properties, structural characteristics, and influence of thermal annealing on selected semiconducting oxides used in Quantum Dot–Sensitized Solar Cells (QDSSCs). Quantum dots, due to their tunable bandgap, strong quantum confinement effect, and ability to generate multiple excitons, offer a promising pathway for improving photovoltaic efficiency beyond conventional silicon solar cells. In this study, semiconductor oxides such as TiO₂ and ZnO were deposited on soda-lime glass substrates using screen printing, chemical deposition, and thermal annealing techniques. Natural dyes extracted through water–methanol solvent methods were used as sensitizers to enhance photon absorption across visible and near-infrared spectra. The prepared thin films were characterized using UV–Vis spectrophotometry, SEM, XRD, and electrical measurements to evaluate their absorbance, transmittance, bandgap energy, surface morphology, and charge transport properties. Thermal annealing was performed at controlled temperatures to examine its effects on crystallinity, particle distribution, optical response, and overall photovoltaic performance. The results are expected to reveal how annealing temperature and oxide composition influence exciton generation, dye–semiconductor interaction, and solar power conversion efficiency. This work contributes to the optimization of low-cost, environmentally friendly QDSSCs by identifying semiconducting oxides with superior optical and structural qualities suitable for high-performance next-generation solar energy devices.