Synergistic role of aluminium sulphate flocculation agent as bi-functional dye additive for Dye-Sensitized Solar Cell (DSSC)

Abstract

In this study, an organic dye sensitizer derived from blackberry fruits was employed, and the influence of aluminium sulphate, Al2(SO4)3·H2O (alum) as a bi-functional (acidification and flocculation) additive in DSSC was investigated. The alum treated dye solution, ATD, was created by adding 0.1 g alum to the dye solution prior to the immersion operation. As reference, an untreated dye solution, UD, was created for comparative purposes. The TiO2 photoelectrodes were characterized through FESEM, EDXs, and XRD techniques, while the dye properties were investigated using UV-Vis and FTIR. Finally, I-V characteristic, IPCE and EIS measurements were used to assess the overall performances of DSSCs. Based on the findings, the photocurrent-voltage conversion efficiency of the ATD, and the non-treated (UD) dye sensitised DSSCs were found to be 0.64 ± 0.02% and 0.44 ± 0.02%, respectively. The role of alum in regulating the acidity of the blackberry dye solution in the ATD photoelectrode mimics the acid treatment process on TiO2 nanoparticles. Furthermore, the purification process of natural dye solution by the flocculation reaction of crude impurities (sugar, protein, etc.) purifies the dye solution even further. The ATD DSSC outperformed the UD by 45.50 ± 0.02% as a result of these combined effects.