Natural dye induced generation of photovoltage using dye sensitized solar cell and photogalvanic cell
摘要
This study compares dye-sensitized solar cells (DSSCs) and photogalvanic cells (PGCs) using natural extracts of Chenopodium album (CA) leaves and Capparis decidua (CD) flowers as photosensitizers. Light-harvesting efficiency and solvent-dependent pigment solubilization were investigated using the UV-Vis spectral characterization in ethanol, dimethy-sulfoxide (DMSO) and isopropyl alcohol (IPA). DSSCs with mesoporous TiO₂ photoanodes, iodide/triiodide redox electrolytes, and platinum counter electrodes continuously outperformed PGCs in terms of performance. DMSO-based DSSCs sensitized with Capparis decidua achieved the highest efficiency (1.490 ± 0.006%), followed by IPA (1.257 ± 0.020%) and ethanol (1.014 ± 0.046%). comparative I-V analysis showed that CD dye performed better than CA in both systems, achieving higher open-circuit voltage, short-circuit current, fill factor, and overall efficiency (η = 1.490% in DSSCs, 0.8902% in PGCs). A mixed dye system (CA + CD) was tested only in DSSCs to improve performance. This system exhibited the highest efficiency (η = 1.703 ± 0.009%) in DMSO. The improved performance is attributed to enhanced light absorption and efficient electron injection from the dye molecules into the TiO₂ conduction band. Although mixed-dye systems can potentially improve light harvesting through complementary absorption, the present work primarily focuses on evaluating the photovoltaic performance of natural dyes. These results demonstrate that plant-derived dyes can serve as environmentally friendly and low-cost sensitizers for sustainable solar energy applications.