Highly Efficient Solid‐State Dye‐Sensitized TiO₂ Solar Cells Using Donor‐Antenna Dyes Capable of Multistep Charge‐Transfer Cascades

Novel ruthenium dyes with electron- donor antenna groups (triphenyl amine and tetraphenylbenzidine) are developed and applied in solid-state dye- sensitized solar cells. The higher absorption arising from extended conjugation in these dyes leads to efficient light harvesting, which in turn results in higher short-circuit currents; multistep charge-transfer cascades take place, very similar to the photosynthetic cascade process (see figure).