Abstract
Ar/O plasma irradiation is proposed for post-treatment of vanadium dioxide (VO₂) films. Oxidation and surface migration were observed in the VO₂ films following irradiation. This combined effect leads to an effective stoichiometry refinement and microstructure reconstruction in the interfacial area. A notable improvement in luminous transmittance and an enhancement in phase transition performance of the treated VO₂ films were achieved. Compared with that of as-deposited VO₂ films, the electrical phase transition amplitude of treated films increased more than two-fold. The relative improvement in luminous transmittance (380⁻780 nm) is 47.4% (from 25.1% to 37%) and the increase in solar transmittance is 66.9% (from 29.9% to 49.9%), which is comparable to or better than the previous work using anti-reflection (AR) coatings or doping methods. The interfacial boundary state proved to be crucial and Ar/O plasma irradiation offers an effective approach for further refinement of thermochromic VO₂ films.