Existence of electrochromic reversibility at the 1000th cyclic voltammetry for spin coating WO₃ film

The precursor solutions prepared using sol-gel method are used for the synthesis of WO₃ films by spin coating method. The onset of the crystalline phase of WO₃ occurs at 400 °C and it becomes completely crystalline at 500 °C. However, the amorphous film shows an excellent transmittance modulation effect on the visible light than that of crystalline film. The film shows electrochemical reversibility up to 1000th cycle voltammetry and excellent electrochromic behavior. The electrochromic properties of WO₃ film deteriorate after annealing of the crystalline film but their chemical stability is better than the amorphous films. The crystalline film decays very slowly after electrochemical cycles. The electrochromic activity of the studied film indicates that the film has the potential to be used for smart window applications.