Enhancement of Photovoltaic Performance in Dye-Sensitized Solar Cells with the Spin-Coated TiO2 Blocking Layer

The TiO2 thin film layers were introduced with the spin-coating method between FTO electrode and TiO2 photoanode in dye sensitized solar cell (DSSC) to prevent electron back migration from the FTO electrode to electrolyte. The DSSC containg different thickness of TiO2 thin film (10 similar to 30, 40 similar to 60 and 120 similar to 150 nm) were prepared and photovoltaic performances were analysed with I-V curves and electrochemical impedance spectroscopy. The maximum cell performance was observed in DSSC with 10 similar to 30 nm of TiO2 thin film thickness (11.92 mA/cm(2), 0.74 V, 64%, and 5.62%) to compare with that of pristine DSSC (11.09 mA/cm(2), 0.65 V, 62%, and 4.43%). The variation of photoelectric conversion efficiency of the DSSCs with different TiO2 thin film thickness was discussed with the analysis of crystallographic and microstructural properties of TiO2 thin films.