High efficiency dye-sensitized nanocrystalline solar cells based on sputter deposited Ti oxide films

Nanocrystalline solar cells were made by incorporation of cis-dithiocyanato-bis(2,2′-bipyridyl-4,4′-dicarboxylate) ruthenium (II) into sputter deposited titanium oxide films. After a pyridine treatment, it was possible to achieve a photoelectric conversion efficiency as high as 7% for a solar intensity of 100 W/m2 – almost the same as for conventional nanocrystalline cells with colloidally prepared titanium oxide. Transmission electron microscopy indicated a parallel penniform microstructure, and secondary ion mass spectroscopy showed that the dye incorporation was uniform except in the bottom parts of the sputtered films where a decreased porosity seems to limit the penetration of the dye.