Reactive Magnetron Sputtering Doped Tungsten Vanadium Oxide Thin Films

VO₂ thin film is being widely studied as its thermal phase transition characteristic. At 68℃,its structure changes from low-temperature semiconductor to high-temperature metallic,because of which its resistivity and infrared transmittance vary at very large scale.The phase transition temperature needs to be lower to room temperature for applications,such as smart window,infrared detector and etc.Dopant can reduce the phase transition temperature effectually.At present VO₂ thin films are mainly produced by reactive magnetron sputtering. It is very hard to get phase-singled VO₂ thin films because VO₂ is not the highest valance of vanadium oxide,but V₂O₅ films are very easy to get.We can get VO₂ films by annealing V₂O₅ films.We focus on researching the Po₂,sputtering power, sputtering time and substrate on the phases of the films by orthogonal test.After optimizing,phase-singled V₂O₅ film is produced under the power of 150W and the Po₂ more than 15%.We deposited tungsten-doped vanadium oxide films,then researched annealing temperature,annealing time.etc on the phases and morphology of films.As a result, films on SiO₂ glass can become to mainly VO₂ under the temperature of 500℃for 2 hours;and films on float glass will become to mainly VO₂ under the temperature of 500℃for 4 hours or under the temperature of 600℃for 2 hours.On the basis of the former experiment,we refer to the infection of tungsten-doped. We find that films with tungsten-doped become non-crystalline and after annealing under 500℃for 2 hours VO₂ diffraction peaks are less than films without tungsten-doped.After tungsten-doped,the visible light transmittance increases clearly,but the infrared transmittance reduces a little.