Photo current enhancement of natural dye sensitized solar cell by optimizing dye extraction and its loading period

Energy conversion performance of natural dye sensitized solar cells (DSSC) mostly relies on sensitizer. The characteristics of sensitizer are governed by its extraction process parameters. So, this investigation attempts to describe the successful conversion of visible light into electrical energy by employing turmeric (Curcuma longa L.) as a sensitizer that is locally available at Dhaka, Bangladesh, through using dye source in different forms and optimizing some parameters such as dye extracting solvents, pH of solvent, dye loading period and dye adsorption% onto the TiO₂ film. Sensitizers were retrieved from raw and dry turmeric by employing various solvents. The optical absorption, functional anchoring group, surface morphology and elementary composition of the annealed pure nano-crystalline TiO₂ film and dye adsorbed TiO₂ film were investigated by using UV–vis spectroscopy, FTIR, SEM and EDS analysis. Effects of different dye extracting solvents on the optical energy gap were also recorded. Different photovoltaic parameters such as short circuit current density (J_SC), open circuit voltage (V_OC), fill factor (FF) and efficiency (η%) were assessed under 100 mW/cm² illumination. Dependency of cell efficiency on dye loading periods and dye adsorption% onto photo electrode were also analyzed.