Quasi solid state dye-sensitized solar cells with modified TiO2 photoelectrodes and triphenylamine-based dye

Quasi solid state dye-sensitized solar cells (DSSCs) have been fabricated with organic sol or TiCl4 modified TiO2 and porous TiO2 photoanode and a triphenylamine-based dye (TPAR3) used as photosensitizer. Dark current measurements suggested that both modified TiO2 photoelectrodes had significantly reduced the recombination rate of photoelectrons due to the reduced bare FTO surface in comparison to porous photoelectrode. The DSSC based on modified TiO2 photoelectrodes showed improved photovoltaic parameters compared to the porous TiO2 photoelectrode. The overall power conversion efficiency (PCE) is 3.27%, 4.73% and 6.8% for porous, TiCl4 modified and sol modified TiO2 photoelectrodes, respectively. The improved PCE with modified TiO2 electrodes was attributed to the formation of a compact layer. This effectively improves adherence of TiO2 to FTO surface, providing a larger TiO2/FTO contact area and reducing the electron recombination by blocking the direct contact between redox electrolyte and the conductive FTO surface and enhances the electron collection efficiency.