Photovoltaic performance of TiO2 using natural sensitizer extracted from Phyllanthus Reticulatus

Abstract

Phyllanthus reticulatus, a natural sensitizer has been extracted from Karunelli fruit for the fabrication of TiO2 based DSSCs. The extracted dye shows the visible light optical absorption at a wavelength of around 520 nm. The presence of anthocyanin in the dye extract has been identified by the functional molecular groups such as intermolecular –OH bond, conjugate C=O stretching vibrations using FTIR. A commercial P25 TiO2 anatase powder has been employed for the fabrication of photoanode on fluorine doped tin oxide (FTO) substrate using Doctor-blade technique. The Platinum (Pt) counter electrode has been prepared using electron beam evaporation technique with a thickness of ~200 nm. To measure the photoconversion efficiency of the stacked DSSCs, the electrodes are assembled into a cell module and illuminated by a light source simulating AM 1.5 with a light intensity of 100 mW/cm2. The freshly prepared sensitizer (P. reticulatus pH ~5.5) exhibits the photo-conversion efficiency of 0.19%, while decreasing the pH of the sensitizer (pH ~1.0) enhances the photoconversion efficiency to six times (0.69%) higher than that of fresh one.