High-performance photoanode for dye sensitized solar cells with graphene modified two-layer construction

Graphene modified dye sensitized solar cells (DSSCs) show high photovoltaic performances due to the fast electron transport capacity and the large BET area of the additive. However, the corresponding research on how to further improve the properties of DSSCs by optimizing the adopted graphene is insufficient. In this study, reduced graphene oxide (RGO) nanosheets and three-dimensional graphene networks (3DG) are employed to build high performance photoanodes with a two-layer structure by taking full advantages of them, simultaneously. Residual functional groups of RGO support preconditions to construct an electron transport layer between conducting substrate and work layer of photoanode, which is beneficial to depress dark current on the interface. On the other hand, high integrity and continuity of 3DG provide a fast electrons transport network in the work layer, which suppresses the recombination of electron-hole pairs in the photoanode. After optimizing the structure of photoanode, the energy conversion efficiency reaches 8.87%. (C) 2015 Elsevier B.V. All rights reserved.