Photovoltaic study of nanocrystalline TiO₂ film modified with dye molecules

The nanocrystalline TiO₂ film is modified simultaneously with porphyrin dye molecules and phthalocyanine dye molecules by chemical adsorption. Since porphyrin and phthalocyanine dye have different absorption character in the visible range, the TiO₂ electrode sensitized by a combination of porphyrin and phthalocyanine dye molecules not only obtains a better spectral match to the solar spectrum, but also the photoresponse of the electrode is extended to cover most of the visible range. This kind of electrode exhibits a significant improvement of energy conversion efficiency.