Three-dimensional graphene network assisted high performance dye sensitized solar cells

Three-dimensional graphene networks (3DGN5) are prepared by chemical vapor deposition with the nickel foam rod as a template. Continuous structure of the 3DGN efficiently reduces inter-sheet junction contact resistance between the graphene sheets and makes the sample a great channel for carrier transport. The as-prepared 3DGN is added into the photoanode to boost the photovoltaic performance of dye sensitized solar cells (DSSCs). Even the amount of the 3DGN is as low as 0.2 wt%, the short-circuit current density and power conversion efficiency (eta) are obviously improved, which is due to the enhanced dye absorption amount and prolonged electron lifetime. Compared to that of pure P25 photoanode based DSSC, the eta increases 32.7% under AM-1.5G one sun light intensity when the 3DGN (1 wt %)-P25 photoanode is adopted (from 4.96% to 6.58%). After optimizing the thickness of the added 3DGN, the eta further increases to 6.87%. Moreover, DSSCs with the 3DGN based counter electrode are also fabricated, and a slight degradation (in eta) is obtained in comparing with that of employing a Pt counter electrode under identical conditions. (c) 2013 Elsevier B.V. All rights reserved.