A novel wet process for the preparation of vanadium dioxide thin film

Thin films of vanadium oxide have been prepared from an aqueous solution system of (V2O5-HF aq.) with the addition of aluminium metal by a novel wet-preparation process which is called liquid-phase deposition (LPD). From X-ray diffraction measurements, the as-deposited film was found to be amorphous and it was then crystallized to V2O5 by calcination at 400 degrees C under an air flow. In contrast, the monoclinic VO2 phase was obtained when the deposited film was calcined under a nitrogen atmosphere. The deposited film showed excellent adherence to the substrate and was characterized by a homogeneous flat surface. The deposited VO2 film exhibited a reversible semiconductor-metal phase transition around 70 degrees C and its transition behaviour depended on the way in which the film was prepared.