Impact of Various Solvents on Extraction of Anthocyanins from Blueberry for Use in Dye-sensitized Solar Cells

Abstract

We extracted anthocyanins from a natural dye source, blueberry, by a solvent extraction method for use as sensitizers in the fabrication of dye-sensitized solar cells (DSSCs). In the extraction of anthocyanins, we used solvents such as acetonitrile, tert-butanol, ethanol, and acetone, and their effects on the performance of DSSCs were examined. Currently, the available commercial-grade titanium dioxide (TiO2) powder is composed of 80 mol% rutile and 20 mol% anatase phases. In the preparation of the photoanode, the TiO2 powder was applied by a doctor blade technique. The prepared photoanodes were immersed in the extracted anthocyanin dye and exposed for different durations while being shielded from light throughout the process. To prepare electrodes, a platinum film approximately 1 nm thick was sputter-coated onto an indium tin oxide (ITO) glass substrate. Finally, the coated photoanodes were sealed with the electrode by dye-soaking. To evaluate the performance of the fabricated DSSCs, the incident photon-toelectron conversion efficiency (IPCE) was measured by ultraviolet-visible spectroscopy (UV- VIS) and a solar simulator. The results showed that DSSCs with the dye extracted from blueberry in tert-butanol for 12 h showed the best efficiency. In this study, tert-butanol was the best extraction solvent for the fabrication of DSSCs with anthocyanins extracted from blueberry with an efficiency of 0.45% and a fill factor of 68.20%. Further study is required to find a more appropriate solvent and extraction method, while the result of this study proved that the use of a dye from a natural dye source such as blueberry in solar cell technology is promising.