Photovoltaic performance of quasi-solid state dye sensitized solar cells based on perylene dye and modified TiO2 photo-electrode

The influence of compact layer of TiO2 between FTO and nano-porous TiO2 on the charge transport and photovoltaic properties of quasi-solid state dye sensitized solar cells with polymer gel electrolyte and perylene derivative dye as sensitizer was investigated. The PEDOT:PSS/graphite/FTO was used as counter electrodes for present investigation. The modification of photo-electrode significantly improve the power conversion efficiency (2.94%) of the solar cells attributed to the higher electron lifetime and reduction in recombination processes as indicated by the electro-chemical impedance spectra of the solar cell. The compact layer provide a large TiO2/FTO contact area, reduce the electron recombination by blocking the direct contact with the redox couple in the electrolyte and efficient collection of electrons by FTO electrode. Finally, the incorporation of TiO2 nano-particle in the polymer electrolyte further improves the power conversion efficiency (3.2%) of the device attributed to the improved ion transport.