Modifying organic phenoxazine dyes for efficient dye-sensitized solar cells

Four org. dyes bearing the phenoxazine chromophore have been synthesized and applied in dye-sensitized solar cells (DSCs). The effect of different dye structures on the performance of the DSCs was investigated systematically with photophys., photovoltaic as well as photoelectrochem. methods. Due to the slow recombination process between injected electrons and electrolyte, the IB3 dye with two 2,4-dibutoxyphenyl units showed the best efficiency of 7.0% under 100 mW cm-2 light illumination in the liq. state-DSCs. Moreover, the phenoxazine dyes-based solid state-DSCs were fabricated for the first time. With the IB4 dye, a higher efficiency of 3.2% has been achieved under the same light intensity.