High-performance dye-sensitized solar cells with nanomaterials as counter electrode

Abstract

High-performance dye-sensitized solar cells (DSCs) with nanocomposites as counter electrode are reported, since nanomaterials have high specific surface and could have high catalysis. Nanocomposites of carbon nanotubes (CNTs) and conducting PEDOT:PSS (PEDOT:PSS = poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)) were prepared by dispersing CNTs in aqueous solution of PEDOT:PSS. The dispersion is related to the π-π interaction between CNTs and conjugated PEDOT, which is stabilized by the excess PSS in water. Nanocomposite films of CNTs and PEDOT:PSS could be prepared by solution processing. They could have high transparency and high conductivity. Nanocomposite films prepared by drop casting at room temperature were used as the counter electrode of DSCs. The devices exhibited high photovoltaic performance with the energy conversion efficiency of 6.5%, short-circuit current of 15.5 mA cm -2 , open-circuit voltage of 0.66 V, and fill factor of 0.63 under AM1.5 sun light. This performance is close to the devices using conventional platinum as the counter electrode.