Pomegranate leaves and mulberry fruit as natural sensitizers for dye-sensitized solar cells

Abstract

This study employs chlorophyll extract from pomegranate leaf and anthocyanin extract from mulberry fruit as the natural dyes for a dye-sensitized solar cell (DSSC). A self-developed nanofluid synthesis system is employed to prepare TiO 2 nanofluid with an average particle size of 25 nm. Electrophoresis deposition was performed to deposit TiO 2 nanoparticles on the indium tin oxide (ITO) conductive glass, forming a TiO 2 thin film with the thickness of 11 μm. Furthermore, this TiO 2 thin film was sintered at 450 °C to enhance the thin film compactness. Sputtering was used to prepare counter electrode by depositing Pt thin film on FTO glass at a thickness of 20 nm. The electrodes, electrolyte ( I 3 - ), and dyes were assembled into a cell module and illuminated by a light source simulating AM 1.5 with a light strength of 100 mW/cm 2 to measure the photoelectric conversion efficiency of the prepared DSSCs. According to experimental results, the conversion efficiency of the DSSCs prepared by chlorophyll dyes from pomegranate leaf extract is 0.597%, with open-circuit voltage ( V OC ) of 0.56 V, short-circuit current density ( J SC ) of 2.05 mA/cm 2, and fill factor (FF) of 0.52. The conversion efficiency of the DSSCs prepared by anthocyanin dyes from mulberry extract is 0.548%, with V OC of 0.555 V and J SC of 1.89 mA/cm 2 and FF of 0.53. The conversion efficiency is 0.722% for chlorophyll and anthocyanin as the dye mixture, with V OC of 0.53 V, J SC of 2.8 mA/cm 2, and FF of 0.49.