The present work demonstrates the usefulness of nickel oxide as a hole transporting material in solid state dye-sensitized solar cells (SSDSSCs). We report on the photovoltaic performances of sensitized TiO2/NiO heterojunctions, and demonstrate that the TiO2 film thickness and morphology, as well as NiO film thickness, have significant effects on the photovoltaic behaviour of TiO2/NiO SSDSSC. Under 1 sun AM1.5G simulated illumination, the SSDSSCs demonstrated best photovoltaic performance with a short circuit photocurrent density, open circuit voltage, fill factor and efficiency of 0.91 mA cm(-2), 780 mV, 40% and 0.3%, respectively. This study draws attention to the feasibility of enhancing the photovoltaic performance in SSDSSC devices through development of appropriately designed sensitized TiO2/NiO heterojunctions. (C) 2010 Elsevier B.V. All rights reserved.