Study On Preparation And Property Of Tungsten Oxide Films

Tungsten oxide film material is a important functional material. It is studied and applied extensively because of its electrochromic property, gasochromic property, photochromic property, electrochemistry, etc. Especially gasochromic property is applied to gas sensors extensively. In the text, the tungsten oxide films were prepared with sol-gel and reactive magnetron sputtering methods. Firstly, preparative methods and application of tungsten oxide films were summarized. Secondly, theory, technological process and progress of sol-gel method were introduced and analyzed, and theory, characteristic and important factors on reactive magnetron sputtering were presented in detail. At the same time, conception and merits of orthogonal experiment design were presented. At last, Peroxopolytungstic acid sol-gel and reactive magnetron sputtering methods were used to prepare tungsten oxide films after comparing many preparative methods of tungsten oxide film. Main reagents, main instrumentation, preparation work, test procedure and technological process of peroxopolytungstic acid sol-gel and reactive magnetron sputtering methods were presented in detail. Further more factor level charts of orthogonal test were listed. The tungsten oxide films by two methods were characterized by atomic force microscope, double-beam UV-VIS-NIR spectrophotometer and X-diffractometer. As results of AFM, molecular of sample by sol-gel has obvious tetrahedron and the molecular of sample by DC reactive magnetron sputtering tends to be planar structure, the film prepared by DC reactive magnetron sputtering is denser and evener than the film prepared by sol-gel. As results of transmittance, the transmittance of samples by two methods is similar, but for the samples by reactive magnetron sputtering, transmittance at different wavelength vary more obviously than that by sol-gel; transmittance doesn't change almost after annealing at 200℃,but transmittance decrease obviously after annealing above 300℃, and transmittance is lower when annealing temperature is higher. As results of x-diffractometer, film samples are amorphous state when annealing temperature is under 350℃; the samples change from amorphous state to crystalline state when annealing temperature is 350℃-400℃; film samples change from one crystalline system to two crystalline systems when annealing temperature is 450℃-500℃。Film samples by two methods are even and compact, and transmittance is high, which is important foundation of preparation of doped tungsten oxide films.