A flexible carbon counter electrode for dye-sensitized solar cells

A pure carbon counter electrode (CE) for dye-sensitized solar cells (DSCs), has been fabricated using an industrial flexible graphite sheet as substrate and activated carbon as the catalytic material. The CE shows very low series resistance (Rs) and charge-transfer resistance (Rct) by combining the high conductivity of the flexible graphite with the high catalytic property of activated carbon. The Rs and Rct for the CE are respectively only a quarter and two-thirds of those for a platinized fluorine-doped tin oxide glass (Pt/FTO). DSCs with cell areas of 0.15 and 1 cm2 fabricated with this CE show higher solar-to-electricity conversion efficiencies. The respective values are 6.46% and 5%, compared with 6.37% and 2.91% for the Pt/FTO based devices.