Vanadium oxides prepared by liquid injection MOCVD using vanadyl acetylacetonate

Atmospheric pressure liquid injection MOCVD was used for the deposition of vanadium oxide coatings using vanadyl acetylacetonate as precursor in methanol solution. The deposition was carried out on SiO₂-precoated glass using oxygen flow rates of 0, 0.02, 0.04, 0.06 and 0.08 L/min over the temperature range 375-450 °C. For growth at the highest temperatures studied, which gave the best results in terms of film crystallinity, the influence of oxygen flow rate on the degree of crystallinity, microstructure and morphology of the films was studied in detail. The films were characterized by X-ray diffraction, IR reflectance-transmittance, Raman microscopy and scanning electron microscopy. Results obtained demonstrate the thermochromic properties of vanadium oxide films at a switching temperature at 60 °C together with the fact that liquid injection MOCVD is an efficient method of producing vanadium dioxide using vanadyl acetylacetonate as precursor. The capability to control the microstructure and properties of VO₂ films grown on SiO₂-precoated glass by altering the process parameters can be significant for certain practical applications of thermochromic coatings, such as 'smart windows'.