Several complementary investigation techniques like BET, SEM, Raman and XRD were used to follow the influence of the reactants molar ratio and thermal treatment on the TiO2 aerogel structures. In order to optimize the morphology and to achieve a desired functionality as potential photovoltaic devices the parameters employed for sample preparation were correlated with their structural properties. Firstly, the TiO2 aerogel sample with the highest surface area and anatase structure was identified. Further investigations of this untreated as well as heat-treated aerogel (300-600 degrees C) were performed and useful relationships between the morphology acquired from XRD data and structural properties obtained from Raman spectra were found. TiO2 aerogel thin films have been successfully deposited on a glass substrate and annealed at 500 degrees C. The obtained results made possible the dimensional characterization of the TiO2 aerogel crystallites, which form a thin film, by simple measuring of a Raman spectrum. (c) 2005 Elsevier B.V. All rights reserved.