Enhancing solar energy harvesting through TiO2-Fe2O3 composite photoanodes sensitized with natural dyes in photovoltaic cells

Abstract This study investigated the enhancement of photovoltaic efficiency of dye-sensitized solar cells (DSSCs) through titanium dioxide (TiO 2 ) anodes composite with iron oxide (Fe 2 O 3 ). TiO 2 with Fe 2 O 3 at different weight percentages (0–30 wt%) were employed as photoanodes in DSSCs, prepared via mechanical mixing. Natural dyes extracted from Chrysanthemum violet and Alstroemeria flower petals were used as sensitizers, with platinum (Pt) cathode being employed to facilitate the photocatalytic process. The electronic excitation and molecule vibration characteristics of the dye molecules were investigated by UV-Vis and FTIR spectroscopy, respectively. For the analysis of the photovoltaic parameters, electrochemical characterizations were performed. The performances of the Chrysanthemum violet dye-sensitized cells with 10%, 20%, and 30% composite were 3.24%, 5.25%, and 4.15%, respectively, compared to 1.35% for the mere TiO 2 cells. Similarly, the photovoltaic conversion yields of the Alstroemeria dye-sensitized cells were 3.54%, 6.33%, and 5.74%, while the mere TiO 2 cells showed 1.74%. In both cases, composite with 20% Fe 2 O 3 resulted in the highest efficiency. The findings indicate that this doping technique substantially improves the performance of DSSCs, reaching up to four times the efficiency compared to the mere TiO 2 cells. These results are promising and reinforce the potential of DSSCs in sustainable electricity production.