Improvement of efficiency of Dye Sensitized Solar Cells by optimizing the combination ratio of Natural Red and Yellow dyes

Abstract To improve the efficiency of dye-sensitized solar cells (DSSCs),light absorption properties of organic dye must be tuned to have a maximum response throughout visible and near infra-red spectrum. This work is focused on the study of DSSC based on the combination of red (Red spinach) and yellow (Turmeric) natural dyes used as sensitizers for semiconductor TiO2 as electron conductor in order to improve the efficiency.Combination of natural dye with optimized choice of the agents indicated improved photovoltaic impacts contrasted with single individual dye sensitization and increased the absorption of solar light and allowed utilization of the photon energy more efficiently.Power conversion efficiency (η %) of natural yellow dye extracted from turmeric (Curcuma longa) was obtained 0.378% and for natural red dye extracted from red spinach (Amaranthusdubius) was 0.134%.The maximum open circuit voltage (VOC = 499.3 mV) and the short circuit current-density (JSC = 4.264 mA cm−2) were obtained from DSSC sensitized by the optimum combination of 60% yellow (Turmeric) and 40% red (Red Spinach) and corresponding maximum efficiency (η %) was reached 1.078%. Thus efficiency with combined dyes is about 2.85 and 8.04 times higher than that of the efficiency of individual single yellow and red dyes, respectively.