Alkoxide Method Preparing Tungsten Trioxide Thin Film

Tungsten trioxide thin films has optical properties, electrical properties, magnetic properties, chemical properties, mechanical properties, thermal properties, etc., it has a variety of properties and thus be applied in many fields, for example, it is used as electrical film, optical film, hard film corrosion film, lubricating film, decorative film, packaging film. Among the many film material, tungsten trioxide thin films have good electrochemical performance, so it has been widely used, such as discoloration smart windows, gas sensors, pH meter and so on. At the present, many researchers have studied tungsten trioxide thin film material, especially the photochromic electricity and electrochemical properties.

Preparation steps:
1. Putting the base W into the alkoxide solution in dry N₂ atmosphere, pulling out of the base by the electric;
2. Drying and removing excess organic solvent in an atmosphere of dry nitrogen coating, the process should be about 30min;
3. Ensuring sufficient hydrolysis to form gel films in humidity atmosphere of 30%, so that W-OR (organic material) can become into W-OH and R-OH (finally evaporated), this process can keep1h;
4. Heating the thin film, the treatment consists of two processes: the first step is heating it at 200 ℃, keeping it 30min; the second step is heating it at 430 ℃ , and removing the residual organic solvent, so as to form thin film of tungsten trioxide.

The study shows that tungsten trioxide thin film density is lower than the material density (7.16g / cm³), it is 0.57 before the heat treatment, and it becomes 0.64 after annealing at 180 ℃, which leads tungsten trioxide thin film to form microcrystalline structure.