The catalytic effects of graphene oxide (GO) films were investigated for dye-sensitized solar cell (DSSC). The GO film consisted of a networked structure of two phases of GO with intercalated H(2)O and exfoliated GO. A maximum solar power conversion efficiency (eta) of 2.30% was obtained for the ultrathin GO film. This eta is higher than that of other reported types of DSSCs (0.84%) and organic solar cells (1.1%) with graphene electrodes. The catalytic effect of the GO film is attributed to the good ion permeability along the interlayer hydrophilic spaces; the electrons present in these spaces on the exfoliated GO were supplied to the iodide ions. (C) 2011 Elsevier B.V. All rights reserved.