Dynamic behaviors of inorganic all-solid-state electrochromic device: Role of potential

Applied potential plays a significant role in the properties of electrochromic devices (ECDs), for example, cyclic property, optical modulation, and response rate. In this study, inorganic all-solid-state ECDs with the multilayer structure of Glass/ITO/NiOx/Ta2O5/LiNbO3/Ta2O5/WO3/ITO were prepared by magnetron sputtering. The potential dependence of charges dynamic behaviors in the ECDs were analyzed on the basis of cyclic voltammograms (CVs), chronoamperograms (CAs), multi-potential steps, and in-situ optical transmittance at 550 nm. Results demonstrated that the trapping of Li+ ions in NiOx layer and in WO3 layer were responsible for the degradation of electrochromic properties of the ECDs operated at different potential ranges. Besides, the dynamic behavior of Li+ ions in WO3 layer, acting as the primary electrochromic layer in the ECDs, had a crucial influence on the response characteristics of the ECDs. Excellent optical memory effects at randomly electrochromic extent were observed and the corresponding open-circuit potential was relevant to the chemical potential of the ECDs.