Effect of natural dye extracting solvents on the performance of dye-sensitised solar cells

Abstract

Dye-sensitised solar cells (DSSCs) have attracted immense attention in photovoltaics research and development due to the low cost of fabrication, sustainability and use of abundant natural resources. Natural dyes were adapted to DSSCs as a sensitiser but unfortunately proved to have poor efficiency. Herein, we manufactured two organic dyes from yellow and red gambier fruits and treated both dyes with methanol and isopropyl alcohol. The photoanode and photocathode were prepared from TiO2, sensitiser and indium thin dioxide (ITO); and carbon and indium thin dioxide, respectively. An electrolyte was made by mixing potassium iodide and iodine. The doctor blade method was used to add the semiconductor to the surface of the conducting ITO. UV-Vis and FTIR spectroscopic measurements have been performed to determine the absorbance and functional groups in the gambier extracts. From the analysis of UV-Vis and FTIR spectra, and photovoltaic measurements made under solar irradiation, we found that the gambier extracts are dominated by tannin and flavonoids and that dyes using isopropyl alcohol as the solvent have higher efficiency than using methanol, respectively. This indicates that the gambier extracts and solvents might influence the performance of DSSCs.