(103a) Graphene Aerogel-Based Counter Electrodes for Dye- Sensitized Solar Cells

Graphene aerogels were prepared following an organic sol-gel process developed by Worsley et al. [Ref. 1] with some minor modifications. Under preferred reaction conditions, the graphene aerogels obtained were with a high specific surface area of 814 m²/g and a high electric conductivity of 850 S/m, and were applied as a counter electrode material for dye-sensitized solar cells. The performance of the graphene aerogel in dye sensitized solar cells was found to be dependent on its film thickness, with thicker films offering more surface areas for the involved catalytic reaction but at the same time increasing the charge transport resistance. At a graphene aerogel film thickness of 4.9 μm, a power conversion efficiency of 96% of that achieved with the Pt counter electrode based DSSC was obtained. In addition, a thinner graphene aerogel film of 1.7 μm, when loaded with Pt of 1 mole% through a light reduction procedure, achieved a power conversion efficiency of 98% of that obtained with the Pt counter electrode based DSSC. The excellent performances of the graphene aerogel-based counter electrodes were manifested with electrochemical impedance analyses and cyclic voltammetry catalytic activity analyses.

Ref. 1: M.A. Worsley, P.J. Pauzauskie, T.Y. Olson, J. Biener, J.H. Satcher, Jr., T.F. Baumann, J. Am. Chem. Soc., 132, 14067 (2010).