A novel film fabrication technique, i.e. electrostatic sol-spray deposition (ESSD), has been used in this study to prepare TiO2 thin films of various surface morphologies and crystalline structures. Scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and UV/Vis absorption spectroscopy were employed to characterize the as-deposited and annealed TiO2 thin films. It has been found that silicon dopant can increase the anatase-to-rutile phase transformation temperature up to about 1050°C. Two possible mechanisms are proposed to explain the phase stabilisation effect, i.e. reduction of the oxygen vacancy concentration by dissolution of SiO2 in the TiO2 lattice and segregation of a SiO2 second phase. The energy bandgap of amorphous SiO2 doped TiO2 films decreases with increasing annealing temperature.