ITO/Cu multilayer electrodes for high-brightness electrochromic displays

• Published in: eScience (Beijing) Vol. 2; no. 6; pp. 632 - 638
• Main Authors: Tang, Xueqing, Hu, Zishou, Wang, Zhen, Chen, Jian, Mu, Xinyang, Song, Ge, Sun, Peiyan, Wen, Zhengji, Hao, Jiaming, Cong, Shan, Zhao, Zhigang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2022; KeAi Communications Co. Ltd
• Subjects: Copper; Electrochromic; High brightness; Tungsten trioxide; Copper; Electrochromic; Tungsten trioxide; High brightness
• ISSN: 2667-1417; 2667-1417
• DOI: 10.1016/j.esci.2022.08.005

Fabry–Perot (F–P) nanocavity-type electrochromic devices with multicolor tunability have attracted significant interest in the past two years for their potential uses in a wide variety of applications, such as electronic display, military camouflage, and dynamic decoration. However, challenges such as insufficient brightness, lengthy switching times, and poor cycling stability have yet to be overcome. Herein, we demonstrate electrochromic electrodes based on ITO/Cu as both the current collector and the reflective layer, with WO3 as the electrochromic material, forming a unique three-layered structure. The constituted WO3/ITO/Cu films present a high brightness value of about 84% before coloration, and a decent brightness value of 48% after coloration at −0.8 ​V. Moreover, a fast switching time between different coloration states (tc ​= ​2.2 ​s; tb ​= ​1 ​s) is recorded, attributed to the extremely low sheet resistivity of the ITO/Cu current collector. The films also reveal excellent electrochemical cycling stability across 2000 cycles. [Display omitted] •WO3/ITO/Cu film is designed as electrochromic electrode producing a high pristine brightness of 84% and a decent brightness of 48% when colored at the rather high voltage of −0.8 ​V.•The high-brightness WO3/ITO/Cu electrochromic electrodes reveal excellent electrochemical cycling stability over 2000 cycles, benefiting from the ITO coverage of Cu layer against oxidation.•Due to the extremely low sheet resistivity of the ITO/Cu film (0.54 ​Ω/□), rapid switching between coloration (tc ​= ​2.2 ​s) and bleaching (tb ​= ​1 ​s) is achieved with WO3/ITO/Cu electrodes.