The application of a three dimensional CNT-sponge as the counter electrode for dye-sensitized solar cells

A sponge-like three dimensional carbon nanotube (CNT) framework has been applied as the counter electrode for a dye-sensitized solar cell (DSC). The CNT-sponge shows high catalytic activity to the counter electrode reduction reactions of I−/I3− redox couple and a photoelectric conversion efficiency of 6.21% has been achieved. Compared with previous carbon-based counter electrode materials for DSCs, the CNT sponge retains highly flexibility and good mechanical strength. Its soft structure makes it possible to directly transfer it onto a substrate to make DSC devices.