Structural and infrared-emission properties of W ion-implanted VO₂ films

Vanadium dioxide (VO₂), a typical metal insulator transition material, potentially has wide applications in functional materials due to a change in property before and after phase transition．But such applications are limited by the phase transition temperature of 68.0 ℃．In this work, monoclinic VO₂ prepared on SiO₂/Si substrate was doped with low doses of W ions after ion implantation, before the films were annealed．Crystal structure of VO₂ films was damaged by W ion implantation at 1×10¹⁵ ions/cm²．After annealing at 400 ℃, monoclinic crystal structure of the film was partially recovered．After annealing, phase transition temperature of VO₂ thin films decreased by 8.9 ℃ with doping of 0.12%, the change rate being 74.2 ℃．Infrared emissivity was reduced to 0.46-0.35．Infrared emissivity in low temperature region was 0.14 lower than the original VO₂ film．These changes greatly improved infrared stealth performance of the film in low temperature region．