Development of dye-sensitized solar cell based on combination of natural dyes extracted from Malabar spinach and red spinach

Herein, natural green and red dyes have been extracted from Malabar spinach (Basella alba) and red spinach (Amaranthus dubius), respectively, and were used as a sensitizer source for TiO2 photoanode based dye sensitized solar cell (DSSC). The cell efficiency of the developed DSSC sensitized with single individual green and red dyes were obtained, 0.466% and 0.531%, respectively. To improve the cell efficiency of natural dye-based DSSC, natural green and red dyes have been combined at 5 different volume ratios, to find the optimum combination of dyes. From the UV-Vis absorption spectrum, the combination of dyes showed cumulative absorption properties of both single individual dyes. DSSC co-sensitized with the optimum combination of dyes (20% green + 80% red) exhibited the best performance of open circuit voltage of 385 mV, short circuit current of 4.273 mA, fill factor of 0.515 and the highest cell efficiency of 0.847% under 100 mW/cm(2) illumination at AM 1.5G condition. The optimised cell efficiency was found 0.847% which is almost 1.82 and 1.6 times higher than that of the single individual green and red dye-sensitized DSSC's cell efficiency.