Tungsten Oxide Thin Film Recycling Times

For the different deposited tungsten oxide thin film under different parameters, make the experiment of recycling for the coloring state and fading state, by increasing the distance between electrodes, reducing the ion implantation amount during per unit of time, dilute electrolyte solution, lower the voltage and other measures to reduce the impact of electrolyte solution on the recycling times of thin film.

In the experiment, transmittance of thin film under fading state almost stays the same. The coloring state stays stable in the first five recycles, without annealing under room temperature, after five cycle times thin film will peel off. After 100 ° C annealing, the film can be recycled about 150 times, after 200 times it loses basic ability to change color; annealed at 200 degree Celsius it can be recycled for 300 times, it loses electrochromic property when exceeding 300 times.

Thin film lost electrochromic capacity during electrochromism process is because the coloring and fading cycles of experiment changes structure of thin film, the resistance increases, the injected ion and electron becomes stable structure in thin film which can not be extracted out of thin film at one time. It accumulated gradually, as a result, the ion diffusion path is blocked, the conductive layer and surface of conductive film is corroded by electrolytic solution, the transmission path is destroyed which together result in the lost of electrochromic capacity of thin film.