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

Nanocryst. 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 photoelec. conversion efficiency as high as 7% for a solar intensity of 100 W/m2 - almost the same as for conventional nanocryst. cells with colloidally prepd. 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.