Variation of carboxylate-functionalized cyanine dyes to produce efficient spectral sensitization of nanocrystalline solar cells

The sensitizing properties of cyanine dyes in dye-sensitized nanocrystallin e TiO2 solar cells are shown to be controlled by the character of the carbo xyl functions used to attach the molecules to the surface. These tether fun ctions affect the degree of aggregation of the subject cyanine dyes attache d to TiO2 as well as the short circuit photocurrents they produce in these solar cells. Use of two carbons, acetic acid linkages, on the dye results i n performance in a sensitized solar cell comparable with a control rutheniu m complex, in contrast to the greatly diminished performance of dyes with l onger, methylbenzoic acid linkages. (C) 2000 Elsevier Science Ltd. All righ ts reserved.