Study of graphene nanoflake as counter electrode in dye sensitized solar cells

Graphene nanoflake (GNF) films have been fabricated on a fluorine doped tin oxide (FTO) glass using a doctor blade method and thermally annealed in air and argon ambient at various temperatures. The GNF/FTO thin films were employed as a counter electrode for dye sensitized solar cells (DSSCs). Results showed the GNF/FTO film could enhance the power conversion efficiency (PCE) of DSSC devices more effectively when annealed in argon ambient rather than in air and at annealing temperatures higher than 380 degrees C. The PCE enhancement was mainly due to the lowered oxygen concentration in the film and the elevated electrical conductance. A PCE of 6.08% or 88% of that with a Pt counter electrode has been achieved for DSSCs with a GNF counter electrode, suggesting that GNF is a highly potential candidate to replace Pt catalyst. (C) 2016 Elsevier B.V. All rights reserved.