ABSTRACT

Living plants have been found to produce bioelectricity by turning sunlight into electricity based on the photosynthesis theory. This technology has the potential to provide a continuous, clean energy supply without relying on traditional means of generating electricity. In this study, natural dyes was extracted from ubengba leaf (Canarium schweinfurthii), pumpkin leaf (Telfairia occidentalis), and turmeric leave (Curcuma longa) respectively, and were analyzed as a potential sensitizer for the development of dye sensitized solar cell. The optical characteristics of the extracted dyes were studied using UV-VIS spectrophotometer 1601 PC. The extracted dyes showed a broad range of absorption within the visible region between 340nm to 550nm wavelengths. Absorption peaks were found at 422nm wavelength for ubengba leaf, 37mm and 522nm wavelength for pumpkin leaf and 457nm wavelength for turmeric leaf The natural dyes showed good transmittances between 470nm to 800nm, hence complete visible spectrum is available for the dyes to absorb photon energy. The absorption and extinction coefficients of the dyes showed a wide range of absorption from 300nm to 550nm wavelength. Above 550nm wavelength, the absorption and extinction coefficient is almost zero indicating that dye absorbs very little light above 550nm wavelength. From tauc plot, the natural dye from pumpkin leaf showed a higher bandgap of 3.13 eV, while that of ubengba and turmeric showed bandgap of 2.48eV and 2.41eV.