New chromophores were explored for use in dye-sensitized solar cells. The a
ttachment of various di-carboxylated cyanine dyes to nanocrystalline TiO2 w
as examined spectroscopically and through their performance in a sensitized
solar cell. It was found that aggregated forms of these cyanine dyes sensi
tized with an efficiency equal to that of the monomer form and that combina
tions of cyanine dyes could be used to sensitize solar cells over the entir
e visible spectrum. With the high extinction coefficients of the organic dy
es, short circuit photocurrents for these cyanine-sensitized systems was ma
ximized at a 4 mum thickness of the nanocrystalline TiO2. Short circuit pho
tocurrents for these 4 um solar cells were found to exceed that of rutheniu
m coordination complexes.