Design of high-efficiency organic dyes for titania solar cells based on the chromophoric core of cyclopentadithiophene-benzothiadiazole

Based upon the chromophoric core of cyclopentadithiophene-benzothiadiazole, we have finely tailored a metal-free organic dye which displays power conversion efficiencies at various irradiances of the simulated air mass (AM) 1.5 sunlight of 11.5–12.8%, setting a new benchmark for organic dye-sensitized solar cells.