The Electrochromaticity Properties Of WO₃ Thin Films Deposited By Reactive Magnetron Sputtering

WO3 is probably the most promising one of various electrochromaticity materials due to its excellent electrochromaticity properties. It can be applied in many fields such as large display devices, smart windows, and windshields; etc.In this thesis, WO3 is taken as the study object, and the purpose of this study is to investigate the effects of sputtering conditions, such as the deposit speed, film structures and electrochromaticity properties. WO3 films were deposited by reactive magnetron sputtering. Amorphous WO3 films and TiO2-surface modified WO3 films were prepared by using pure tungsten and pure titanium targets, on the ITO-Glass. X-ray Diffraction (XRD), Atomic Force Microscope (AFM), Spectrophotometer and Electrochemistry were used to characterize the structure and Li+ electrochromaticity properties.The result shows that it is available to deposit WO3 films by reactive magnetron sputtering. The as-deposited films prepared at room temperature or annealed at temperature below 300℃are amorphous. The margin transmission in the colored and the bleached states can reach to 61.42% with good Li+ electrochromaticity properties. For the amorphous WO3 films, Li+ diffusivity can reach to 2.18×10-10cm2·s-1,in the colored state, and 0.63×10-10 cm2·s-1 in the bleached state with good Li+ diffusion. Along with the increase of annealing temperature, the structure of the films will be changed to crystalline, but the Li+ electrochromaticity properties will be a little bit bad. The voltage of electrochromaticity can't be too high to destroy WO3 films. The best value is 3.5v. TiO2-surface modified WO3 films can get the waterproof capability, but the electrochromaticity properties will decrease.