Effect of vacuum ultraviolet light illumination on the crystallization of sol–gel-derived titanium dioxide precursor films

Crystallization behavior of sol–gel-based TiO2 precursor films by vacuum ultraviolet (VUV) light illumination was investigated. VUV light illumination induces densification of films. This reaction accompanies the removal of organic compounds and OH groups with increasing apparent coordination number of titanium in the film from five to six. This structure change enhances film crystallization; polycrystalline anatase films were obtained by post annealing at 300 °C. Crystallization behavior suggested that proper balance of densification and removal of organic compounds are important tasks for further lowering crystallization temperature.