Bimodal mesoporous, anatase TiO2 microspheres with particle sizes ranging from 0.3 to 2 mu m were synthesized using a facile solvothermal method. The photovoltaic performance of TiO2 microspheres in dye-sensitized solar cells (DSSCs) using a solid state electrolyte was investigated. The solid state electrolyte DSSC device based on the TiO2 microspheres exhibits an energy conversion efficiency of 4.2%, which is greater than that of commercial P25 TiO2 (3.6%). The higher photocurrent density was primarily achieved as a result of the greater specific surface area and pore size, which resulted in an increase in the dye uptake of the TiO2 microspheres and easy transport of solid electrolyte through mesopores. In addition, the greater electron lifetime and superior light scattering ability also enhanced the photovoltaic performance of the TiO2 microsphere-based, solid state DSSCs. (C) 2012 Elsevier Ltd. All rights reserved.