Preparation and performance of fast-response ITO/Li-NiO/Li-WO3/ITO all-solid-state electrochromic devices by evaporation method

In this study, all-solid-state electrochromic device (ECD) with a novel four-layered structure of glass/ITO/Li-NiO/Li-WO3/ITO was prepared by e-beam and resistive heating evaporation. Tungsten oxide (WO3), nickel oxide (NiO) and indium tin oxide (ITO) were used as electrochromic layer, complementary layer and electrode layer, respectively. Lithium was used as electrolyte ion and evaporated on the complementary layer directly, replacing the normally used independent electrolyte layer. Since the lithium ions can transfer between WO3 and NiO layer directly during the electrochromic process, the ECD shows a fast response speed with coloring and bleaching time of 8.6 s and 1.7 s, respectively, due to the reduction of the overall resistance of the device. The unique structure of ECD may further advance the development in the practical applications. (C) 2020 Elsevier B.V. All rights reserved.