Green Fabrication of Dye-Sensitized Solar Cells Using TiO2 and Four Natural Leaf Dye Extracts

Abstract

Different natural dye extracts were prepared and used as sensitizers in the fabrication of dye-sensitized solar cells (DSSCs). A dense TiO₂ blocking layer was deposited by spray pyrolysis and characterized by profilometry, while a mesoporous TiO₂ layer was subsequently deposited by screen printing. DSSCs sensitized with extracts from Dacryodes edulis, Mimosa pudica, Delonix regia, and Xanthosoma sagittifolium were fabricated and characterized under an illumination intensity of 100 mW/cm². The short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), and conversion efficiency (η) were determined. Delonix regia exhibited the highest conversion efficiency of 0.0555%, with Jsc = 0.196 mA/cm², Voc = 0.483 V, and FF = 0.586. Dacryodes edulis, Mimosa pudica, and Xanthosoma sagittifolium recorded efficiencies of 0.0106%, 0.0044%, and 0.0113%, respectively. The results demonstrate measurable photovoltaic responses from all four natural dye extracts, with Delonix regia producing the highest response under the experimental conditions. However, the relatively low conversion efficiencies indicate the need for further optimization of dye extraction, sensitization, TiO₂ film characteristics, and cell fabrication conditions.