Tungsten-doped vanadium oxides prepared by direct liquid injection MOCVD

This paper examines the effect of doping on vanadium(IV) oxide (VO2 (M)) coatings on glass, using atmospheric-pressure, direct liquid injection metal-organic (DLI-MO)CVD, which potentially may find application as part of smart glazing units. It is found that tungsten-doped VO2 (M) deposited on commercial SiO2-precoated glass using a 0.1 M solution of vanadyl(IV) acetylacetonate (VO(acac)(2)) and tungsten (VI) ethoxide (W(OC2H5)(5)) in methanol shows a reduction in thermochromic transition temperature (T-c) from 60 degrees C in VO2 (M) to 35 degrees C in V0.98W0.02O2. This finding is discussed in terms of various atomic percentages of tungsten and oxygen flow rates. The crystallinity, composition, morphology, optical properties, uniformity, and oxidation phase of the films are evaluated by X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), scanning electron microscopy (SEM), IR reflectance-transmittance, and Raman spectroscopy, respectively. The relationship between dopant concentration and T-c in the most applicable range for solar window coatings is refined by formation of a single-phase film and precise determination of these parameters.