Self-Powered Rewritable Electrochromic Display based on WO_3-x Film with Mechanochemically Synthesized MoO_3–y Nanosheets

Abstract

Electrochromic displays with bistable color states provide a promising means toward transparent human−machine interfaces. However, the need for external power and the weak optical modulation in the visible light region of most electrochromic devices hinder their practical applications in displays. Here we prepare the MoO 3−y /WO 3−x films based on MoO 3−y nanosheets, which show a dark blue color that matches the response of the eye and meets visual comfort standards compared to pure WO 3−x film. By introducing the highly transparent Al 3+ ion hydrogel layer, a convenient electrochromic device driven by the internal chemical potential has been designed. The device based on the MoO 3−y /WO 3−x film exhibits a high optical modulation in the whole visible light range and can operate at self-powered mode with fast response speed and excellent cycle stability. Moreover, we develop an ionic writing board based on the MoO 3−y /WO 3−x film to surmount the fixed display information issue in conventional electrochromic displays. The ionic writing board exhibits excellent visual display quality and realizes arbitrary writing with a self-powered characteristic. This work provides a simple mechanochemical synthesis procedure of MoO 3−y nanosheets and an ingenious design of self-powered electrochromic devices, which will enable the development of next-generation high-performance electrochromic displays.

Self-Driven Infrared Electrochromic Device with Tunable Optical and Thermal Management

“…The switching speed of the device in this work was faster than those of the Al-based ECDs. 35,36 In addition, the device also performed other superior metrics including larger NIR modulation (ΔR = 21.2% at 1500 nm), higher open circuit potential (∼1.36 V), and better cycling performance compared with previously reported flexible IR-ECDs based on W 18 O 49 , polypyrrole, and Prussian blue (Table S2). The optical memory performance is also a crucial parameter for ECDs.…”

Colored electrolytes for electrochromic devices

“…Electrochromic devices, ECDs, are defined as systems that can reversibly change their optical properties in response to an applied voltage [1]. ECDs received growing interests in many applications such as smart windows, rearview mirrors and displays [2][3][4][5][6]. One main challenge of this research field is to achieve a large color palette to diversify its applications, especially for displays.…”

Towards two-dimensional color tunability of all-solid-state electrochromic devices using carbon dots

“…Electrochromic devices (ECDs) have attracted increased attention in smart windows, displays and color-tuneable optical elements because of their zero energy consumption when at various working states ( Ma et al, 2021 ; Kim et al, 2021 ; Cui et al, 2019 ; Seong et al, 2018 ; Park et al, 2017 ; Wu et al, 2021 ). Especially, multicolor electrochromic displays are one of the most versatile applications because they can retain their colored states without the need to supply electrical power.…”

“…Generally, traditional ECDs are composed of five layers, including transparent conductive layer, electrochromic layer, ionic conductor layer, ion storage layer and transparent conductive layer (Thakur et al, 2012). Most of the electrochromic layer and ion storage layer are transition metal oxides, and the color of transition metal oxides is relatively limited (Bueno et al, 2008;Ma et al, 2021;Tang et al, 2021). Consequently, it is a feasible strategy to design multi-color ECDs from the perspective of electrolyte layer (Périé et al, 2022;Chang et al, 2018;Kanazawa and Uemura, 2019;Chan et al, 2021).…”