Controllable synthesis of rutile TiO2 nanorod array, nanoflowers and microspheres directly on fluorine-doped tin oxide for dye-sensitised solar cells

TiO₂ films with different morphology directly grown on fluorine-doped tin oxide (FTO) substrate were prepared via a facile hydrothermal method. Rutile TiO₂ nanorod arrays, nanoflowers film and microspheres film were obtained by changing the volume ratios of HCl and CH₃COOH in solvent with other conditions unchanged, as confirmed by X-ray diffraction, scanning electron microscopy, transmission electron microscope (TEM) and high-resolution TEM. Dye-sensitised solar cell (DSSC) assembled with the TiO₂ microsphere films grown on FTO substrate as photoanode achieves an overall photoelectric conversion efficiency of 1.94% and a short-circuit current intensity of 5.12%mA cm^-2 owing to the rough surface, which is higher than those of nanorod array and nanoflower-based DSSCs. The photovoltaic performance of rutile TiO₂ film-based DSSCs is related to the morphology of the film.