Dye-sensitized nanocrystalline titanium-oxide-based solar cells prepared by sputtering:: Influence of the substrate temperature during deposition

Nanocrystalline titanium oxide films were prepared by DC magnetron sputtering onto SnO2:F-coated glass substrates kept at temperatures in the 50 < tau(s) < 300 degrees C range. Dye sensitization in cis-dithiocyanato-bis(2,2'-bipyridyl-4,4'-dicarboxylate) ruthenium(II) yielded solar cells with a conversion efficiency eta. The dye incorporation was dependent upon tau(s), and an optimum value of eta = 1.7% was found with similar to 0.8-mu m-thick titanium oxide films prepared at 250 degrees C. The microstructure then displayed a well-defined parallel penniform pattern, and the luminous transmittance was 42%. The crystallite size was substantially enlarged at tau(s) > 250 degrees C, and eta showed an ensuing decrease.