Performance of fruit extract of Melastoma malabathricum L. as sensitizer in DSSCs

Dye-sensitized solar cells (DSSCs) with fruit extracts, of Melastoma malabathricum L. as sensitizer, were fabricated. The fruit dye was extracted in two different solvents; de-ionized water (MMD) and ethanol (MME). The dye was subjected to UV-Vis and DSC studies. UV-Vis studies show absorption of light for a wider range of wavelength for MMD as compared to MME. Both MMD and MME were found to be stable till 121°C, as shown by DSC studies, beyond which MME showed unstable behavior. FTIR spectra of MMD and MME along with dye adsorbed TiO2 were recorded. MMD showed better adsorption with TiO2 than with MME. Voc, Jsc and efficiencies of the MMD sensitized solar cells were obtained in the ranges 420-430 mV, 1.25-1.50 mA cm(-2) and 1.11-1.37% respectively, while for MME sensitized solar cells they were in the ranges 370-380 mV, 0.63-0.87 mA cm(-2) and 0.41-0.72% respectively. Preliminary investigation on stability of DSSCs which were fabricated using both the extracts revealed sharp drop in efficiency of DSSC with MME in comparison to DSSC with MMD as sensitizer.