Open circuit voltage (V-oc) and other photovoltaic parameters from fluorine tin oxide (FTO) P3OT/TiO2 Composite solar cells have been investigated in comparison with those from the indium tin oxide (ITO) devices with the same device structure and fabrication process. From the experimental results, the performance of FTO-based devices is better than that of ITO devices in terms of V-oc, short circuit current density (J(sc)), and power conversion efficiency. The origin of V-oc and the higher V-oc of FTO can be explained and estimated by metal-insulator-metal model with a non-ohmic cathode contact. (c) 2005 Elsevier B.V. All rights reserved.