Analysis on dye-sensitized solar cells based on Fe-doped TiO2 by intensity-modulated photocurrent spectroscopy and Mott–Schottky

The pure TiO2 and Fe salts [Fe(C2O4)3·5H2O]-doped TiO2 electrodes were prepared by the hydrothermal method. The pure TiO2 or Fe-doped TiO2 slurry was coated onto the fluorine-doped tin oxide glass substrate by the Doctor Blade method and then sintered at 450 °C. The Mott–Schottky plot indicates that the flat band potential of TiO2 was shifted positively after Fe-doped TiO2. The positive shift of the flat band potential improves the driving force of injected electrons from the LUMO of the dye to the conduction band of TiO2. This study shows that photovoltaic efficiency increased by 22.9% from 6.07% to 7.46% compared to pure TiO2, and the fill factors increased from 0.53 to 0.63.

Graphical abstractA possible model was made by doped-TiO2 for the bilayer structured electrode and dye adsorption in the mesopores.Figure optionsDownload full-size imageDownload as PowerPoint slide