Application of mesoporous carbon to counter electrode for dye-sensitized solar cells

The mesoporous carbons were prepared by the carbonation of the triblock copolymer F127/phloroglucinol-formaldehyde composite self-assembled in an acid medium and employed as the catalyst for triiodide reduction in dye-sensitized solar cells (DSCs). The characteristics of mesoporous carbon were analyzed by scanning electron microscopy, transmission electron microscopy, N2 sorption measurement and X-ray diffraction. The mesoporous carbon with low crystallinity exhibited Brunauer–Emmett–Teller surface area of 400 m2 g−1, pore diameter of 6.8 nm and pore volume of 0.63 cm3 g−1. The photovoltaic performances of DSCs with mesoporous carbon counter electrode were improved by increasing the carbon loading on counter electrode due to the charge-transfer resistance of mesoporous carbon counter electrode decreasing with the increase of the carbon loading. However, further carbon loading increase has no obvious effect on the photovoltaic performance of DSCs with carbon electrode when carbon loading exceeds 300 μg cm−2. The overall conversion efficiency of 6.18% was obtained by DSCs composed of mesoporous carbon counter electrode with the carbon loading of 339 μg cm−2. This value is comparable to that of DSCs with conventional platinum counter electrode.