تهمینه جلالی

Natural dyes have made dye-sensitized solar cells (DSSCs) a promising technology due to their biodegradability, affordability, fabrication simplicity, and cost-effectiveness. This study used the response surface method to determine the best anthocyanin extraction conditions from black plum (Syzygium cumini) fruits. Anthocyanins from several plants have been isolated for photovoltaics. However, anthocyanins from Syzygium cumini differ from other sources due to their wider spectrum coverage, greater light-harvesting efficiency, chemical resistance, and sustainability. The experimental parameters considered for optimization included pH, extraction time, temperature, and solvent type. The analysis of variance (ANOVA) showed that pH and solvent type significantly affect the extraction of anthocyanin dye among the selected variables, with a p-value < 0.05. The model was able to accurately predict the maximal extraction yield of anthocyanin from black plum with a relative error of 0.59 %, as indicated by the experimental data. The extracted dyes were characterized regarding their size distribution, surface charge characteristics, and energy states. The results showed that the extracted dyes possessed an average diameter of 0.3 nm and a zeta potential of ±5 mV, signifying adequate colloidal stability for adsorption onto the TiO2 surface. On the other hand, the experiments showed that the anatase TiO2 paste with a mean size of 21.88 nm, a porosity of 0.49, and a pore size of 13.24 nm was a good candidate for dye adsorption. The impact of electrolyte conductivity on the cells efficiency was assessed by injecting iodide/triiodide at various concentrations into the cells. The photovoltaic experiments demonstrated that increasing the electrolyte conductivity from 15.96 to 26.3 mS/cm increased the efficiency and short-circuit current of the DSSC by 78% and 44.5%, respectively. However, as the electrolyte conductivity increased further, efficiency and short-circuit current decreas