Low-cost coagulation treatment of dye sensitizer for improved time immersion of dye-sensitized solar cells (DSSC)

In this study, titanium dioxide, TiO2 photoelectrodes of dye sensitized solar cells, DSSCs were sensitized with natural blackberry molecule sensitizer, and the role of aluminium sulfate hydrate, Al2(SO4)3. H2O (alum) coagulation agent on the immersion time was successfully investigated. The time for immersing process of TiO2 photoelectrodes in the coagulated dye solution, CADS (treated) and bare dye solution, BDS (untreated) was varied, and the properties that contributed to the highest overall performances at the shortest immersion time were examined. The photoelectrodes were analyzed using Field Emission Scanning Electron Microscope, FESEM, Energy Dispersive X-Ray spectroscopy, EDXs, and X-ray diffraction, XRD methods, while the dye sensitizer properties were optically and chemically examined using UV-Vis Spectroscopy and Fourier Transform Infra-red Spectroscopy, FTIR measurements. Finally, current to voltage, I-V characteristics were used to evaluate the overall performance of DSSCs with varying duration immersion, and due to treatments. According to the findings, the 8-CADS cell had the highest efficiency at the shortest immersion duration, with around 0.49% compared to the 24-BDS cell, which achieved only 0.41% efficiency. This significant time reduction was due to the synergistic effect of alum as a multifunctional treatment agent, which increased the hydroxyl anchoring group, increased the acidification level, and the dye solution purification via coagulation effect, hence remarkably improving the dye adsorption. As a result of these integrated effects of coagulation treatment, the immersion time was reduced from 24 h to 8 h.