In-situ ultra-thin porous poly(vinylidene fluoride-co-hexafluoropropylene) P(VDF-HFP) membranes were prepared by a phase inversion method on TiO(2) electrodes coated with Ru N-719 dye. These membranes were then soaked in the organic liquid electrolyte to form the in-situ ultra-thin porous P(VDF-HFP) membrane electrolytes. Dye-sensitized solar cell (DSC) using the membrane electrolyte exhibited an open-circuit voltage (V(oc)) of 0.751 V, a short-circuit current (J(sc)) of 16.260 mA cm(-2) and a fill factor (FF) of 0.684 under an incident light intensity of 1000 W m(-2) yielding an energy conversion efficiency (eta) of 8.35%. The V(oc), FF and eta of the solar cell using the membrane electrolyte increased by about 5.8%, 2.2% and 5.7%, respectively, when compared with the corresponding values of a cell using liquid electrolyte. However, the J(sc) decreased by about 2.1%. (C) 2008 Elsevier B.V. All rights reserved.