Photo-performance characteristics of Baphia nitida and rosella dye sensitized solar cell

Abstract

The photoelectric effect of four different natural dyes on Dye sensitized solar cell (DSSC) was studied. Baphia nitida dye extracted with an alkali medium, rosella dye extracted with an aqueous and solvent medium and cocktail of baphia nitida and rosella dye were used respectively in the fabrication of Dye sensitized solar cell. The effect of dye Light Harvesting Efficiency (LHE), dye pH, and energy band gap (E) were also studied. From the result, it was observed that Rosella dye extracted with water and ethanol has peaks at 530 nm and 550 nm respectively, while baphia nitida dye extract has its wavelength of maximum absorbance at 540 nm. The mixed dye however had peaks at 450 nm and 470 nm. FTIR spectra of baphia nitida dye and rosella dye showed that both dyes contain hydroxyl and carboxyl groups. DSSC of Rosella dye extract with pH of 2 and E 2.35 eV performed better (efficiency 0.42 %) than DSSC of Rosella with pH of 3.4 and E 2.26 eV (efficiency 0.24 %). The DSSC fabricated with Baphia nitida dye extract (pH 12 and E 2.3 eV) with efficiency 0.58 %, fill factor 0.72 and Voc 0.530 V performed better than all the cells studied. Cell performance of the mixed dye was the least of all the dyes with efficiency 0.074 %, fill factor 0.18, Voc 0.341 V, pH 9 and E 2.59 eV.