Effect of hydrocarbon chain length of amphiphilic ruthenium dyes on solid-state dye-sensitized photovoltaics.

We studied the influence of the hydrophobic hydrocarbon chain length of amphiphilic ruthenium dyes on the device performance in solid-state dye-sensitized solar cells. We found that the dyes with longer hydrocarbon chains gave higher efficiency values when used as a sensitizer in solid-state dye-sensitized solar cells. With increasing chain length, we observed higher currents and open-circuit voltages up to a limiting chain length. We attribute this improvement to the expected larger distance between TiO2 and the hole conductor, which seems to suppress recombination effectively.