Boosting Solar Cell Efficiency: Enhancing Dye-Sensitized Solar Cell Performance with Carbon Quantum Dots and Titanium Dioxide Nanostructures from Sri Lankan Ilmenite

In dye-sensitized solar cells (DSSCs), the performance of commercially available TiO2 (P25, Degussa) is restricted by a low surface area and insufficient particle connectivity, resulting in hindered optoelectronic performance. This study presents an environmentally friendly and sustainable method for synthesizing TiO2 nanoparticles (NPs) using Sri Lankan ilmenite as a raw material. Additionally, carbon quantum dots (CQDs) are synthesized from coconut shells through a one-step hydrothermal carbonization process, providing a green synthesis process for these carbon-based nanomaterials. The study focuses on the performance of CQD-integrated DSSCs, where the photoelectrode is composed of TiO2 NPs. Photovoltaic properties of ruthenium-based DSSCs were evaluated under standard illumination conditions (100 mW cm–2). The results reveal that the integration of anatase TiO2 NPs and CQDs significantly improves particle connectivity within the photoelectrode, thereby enhancing the efficiency of CQD-based DSSCs up to 7.45 from 4.59% due to the increased surface area and connectivity within the films.