Concentrating yellow and red gambier fruit (Uncaria) in isopropyl alcohol to improve the performance of dye-sensitised solar cells

Abstract

The organic dyes used in dye-sensitised solar cells (DSSCs) possess a low efficiency, leading to problems in the development of more efficient and cheaper DSSCs. In this work, we analysed the effect of the concentrations of organic dye from yellow and red gambier (Uncaria) fruits. The concentrations were prepared with isopropyl alcohol at concentrations of 30, 50 and 70%, respectively. Titanium oxide (TiO2) is a semiconductor which was used in this work by utilising the method of the doctor blade, and indium tin oxide (ITO) was used as the conductive glass. The counter electrode and electrolyte were fabricated by burning candle and mixing KI + I2, respectively. The characteristic spectra of UV-Vis and FTIR were used to analyse the gambier fruit. We obtained that the tannins from red and yellow gambier fruit extract are highly potential to apply as a sensitiser in DSSCs. Furthermore, the measurement of current and voltage was employed under sun irradiation. We obtained that the highest efficiencies were 0.819924 % and 1.747999 % for red and yellow extract, respectively. It indicates that the concentration of the organic dye could improve the performance of DSSCs.