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

Abstract

Amorphous tungsten doped vanadium dioxide coatings were grown on SnO 2-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 N 2 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 N 2 flow rate through the tungsten precursor's bubbler, showed the greatest reduction in transition temperature from 65.5 in granular VO 2 to 44 o C in worm-like V 0.985 W 0.015 O 2 structures approaching that required for commercial use as a smart window coating.

Thin Films for Advanced Glazing Applications

“…These show promise as routes to lowering the thermochromic transition temperature without the deleterious effect of metal doping [207]. Work by Greek researchers has demonstrated that amorphous VO 2 still exhibits thermochromic properties although it is noted that the transition width and gradient of such films are wide and sloping and therefore suboptimal for use in energy saving systems [208].…”

Interdependence of Structure, Morphology, and Phase Transitions in CVD Grown VO2 and V2O3 Nanostructures

“…The synthesis of VO2 (M1) films by aerosol-assisted and atmospheric pressure CVD has been extensively investigated mainly due to their easy 3 scalability, lower restriction on volatility of the precursors and easy introduction of dopants in films. [28][29][30] Nevertheless, the deposition of monoclinic VO2 (M1) is only possible in a narrow temperature window around 550 °C and usually only a limited control over surface morphology has been observed. [26,31] Nanostructured surface morphologies play an important role in the thermochromic performance of VO2 films in terms of phase transition temperature and visible light transmission.…”

Advancements, Challenges and Prospects of Chemical Vapour Pressure at Atmospheric Pressure on Vanadium Dioxide Structures

“…More than ten kinds of crystalline phases of VO 2 have been reported elsewhere, whereas some examples are monoclinic VO 2 (M), tetragonal VO 2 (R) and several metastable forms of VO 2 (A), VO 2 (B) and VO 2 (C) [ 4 ]. Among these phases, only the rutile VO 2 (R/M) phase undergoes a fully reversible metal insulator transition at a critical temperature (T c ) [ 1 ], where an abrupt alteration in optical and electronic properties is observed making it ideal for optoelectronic switches [ 5 ], memristors [ 6 ], artificial neuron networks [ 7 , 8 ] and intelligent window coatings [ 9 , 10 ].…”