Optimizing sensitizer concentration from senna tora leaves for enhanced interfacial interactions in dye-sensitized solar cells

A novel approach is adopted for the determination of the optimum concentration of natural dye powder extracted from the leaves of Senna Tora in the solvent ethanol and soak the TiO2 coated FTO substrate to be used as photoanode of dye sensitized solar cell (DSSC). Various concentration (0.5 g/15 ml, 0.75 g/15 ml, 1 g/15 ml and 1.5 g/15 ml) of the dye powder in ethanol is subjected for UV-Visible, FTIR and PL Spectroscopic studies. Solar cells are fabricated with the sensitizer in Photoanode, I-/I-3- electrolyte and counter electrode of graphite coated FTO are subjected for JV characterization to determine the best concentration of dye to give good photoconversion efficiency. From the study, it is found that, among the four concentrations of the dye in ethanol for the extraction of the dye, 1.5 g in 15 ml of ethanol has shown higher efficiency of 2.29 % with fill factor, short circuit current density and open circuit voltage of 0.84, 2.64 mA/cm(2) and 1.03 V.