TiO2 thin films are an important component of dye-sensitized solar cells. For these solar cells, the TiO2 film must be sintered to achieve crystallization and good interparticle connections. Microwave processing may allow a reduction in the required temperature and time for this heat treatment. Therefore, microwave heating of nanocrystalline TiO2 has been investigated. No significant difference was found between microwave and conventional heating in the sintering of TiO2, but microwave heating promotes the phase transformation from anatase to rutile. Microwave heating improved the solar cell performance when a surface treatment of the TiO2 film with titanium isopropoxide was applied. (c) 2006 Elsevier B.V. All rights reserved.