Atmospheric Pressure Chemical Vapor Deposition Of Amorphous Tungsten Doped Vanadium Dioxide For smart Window Applications

Amorphous tungsten doped vanadium dioxide coatings were grown on SnO2-precoated glass substrates using the atmospheric pressure chemical vapor deposition of vanadium (V) triisopropoxide and tungsten (VI) isopropoxide at 450 o C without an oxygen source. The effect of N2 flow rate through the tungsten's precursor bubbler was examined keeping the respective flow rate through the vanadium's precursor bubbler at 4 L min -1 for a growth period of 30 min. They were characterized by x-ray diffraction, Raman and x-ray photoelectron spectroscopy, field-emission scanning electron microscopy and UV-vis/IR transmittance. The samples grown using 0.4 L min -1 N2 flow rate through the tungsten precursor's bubbler, showed the greatest reduction in transition temperature from 65.5 in granular VO2 to 44 o C in worm-like V0.985W0.015O2 structures approaching that required for commercial use as a smart window coating.