Hierarchical vertically oriented graphene as a catalytic counter electrode in dye-sensitized solar cellsElectronic supplementary information (ESI) available: Experimental methods, dummy cell configuration, equivalent circuit, and solar cell photovoltaic parameters. See DOI: 10.1039/c2ta00380e

Vertically oriented graphene (VG) nanosheets are synthesized for counter electrodes (CEs) of dye-sensitized solar cells (DSSCs). The VG electrode exhibits charge transfer resistance about 1% of the Pt electrode and improves power conversion efficiency of DSSCs from 4.68% (for Pt CEs) to 5.36%.