Functionalized graphene/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate as counter electrode catalyst for dye-sensitized solar cells

A (grapheme/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate) graphene/PEDOT:PSS composite film was electrodeposited on fluorine-doped tin oxide conductive substrate by one-step electrochemical polymerization method. The low-cost and platinum-free film was used as counter electrode in (dye-sensitized solar cell) DSSC. The cyclic voltammetry, electrochemical impedance spectroscopy and Tafel measurements indicate that the graphene/PEDOT:PSS composite film has low charge-transfer resistance on the electrolyte/electrode interface and high catalytic activity for the reduction of triiodide to iodide and. As a result, the DSSC based on the graphene/PEDOT:PSS counter electrode showed high power conversion efficiency of 7.86% under a simulated sunlight illumination of 100 mW cm−2 (AM 1.5), which is comparable with the performance of the DSSC based on Pt counter electrode (7.31%).