Colorful Electrochromic Displays with High Visual Quality Based on Porous Metamaterials

Abstract

The introduction of metamaterials into electrochromic (EC) displays has recently inspired a great breakthrough in the EC field, as this can offer a variety of new attractive features, from a very wide gamut of colors to very fast switching times. However, such metamaterial‐based EC displays still face significant constraints when developing from single electrodes to full devices, because other supportive components in devices, such as counter electrodes and electrolytes, significantly affect light propagation and the subsequent perceived color quality in metamaterial‐based EC devices. Herein, a new, cost‐effective device design structured around a new type of porous metamaterial is reported to circumvent the critical problem in metamaterial‐based EC displays. Owing to its unique design, the metamaterial‐based EC device achieves good color quality with no drop in brightness or shift in color chromaticity when compared with a single electrode. Moreover, the porous‐metamaterial‐based EC device can exhibit non‐iridescence and be viewed from a wide range of angles (5°–85°) and has fast switching response (2.4 and 2.5 s for coloration and bleaching, respectively), excellent cycling performance (at least 2000 cycles), and extremely low power consumption (4.0 mW cm−2).

Coexistence of Electrochromism and Bipolar Nonvolatile Memory in a Single Viologen

“…It is noteworthy to mention that the color coordinates of ON and OFF states at the initial and final (after 1000 cycles) states have been changed slightly (for ON state (0.198, 0.262) to (0.177, 0.381) and for OFF state (0.381, 0.362) to (0.426, 0.335)) (Figure S11). We have calculated the color variation (Δ C ) between the initial and final stage, which can be described as the linear distance between the color coordinates in CIE 1931, given by normalΔ C = false( x 1 − x 2 false) 2 + false( y 1 − y 2 false) 2 where ( x 1 , y 1 ) and ( x 2 , y 2 ) are the color coordinates of the initial and final state, respectively. The color shifts for ON and OFF conditions are found to be 0.1 and 0.05, which indicates minimal degradation of devices after 1000 switching cycles.…”

Advances in multicolor electrochromic devices based on inorganic materials

“…However, the usage of expensive metals and liquid electrolytes hinders the device performance and wide-spread utilization. Therefore, Li et al 75 deposited W and WO 3 on a porous nylon-66 film to construct an F–P cavity, and placed the electrolytes and counter electrodes behind the porous nylon-66 film. The introduction of counter electrodes ITO and polyacrylate-based solid polymer electrolyte resulted in a typical device structure (consisting of the W/WO 3 bilayer and ITO counter electrode) can cause the peak reflectivity to decrease by 53.6%.…”

“…Up to now, although the F–P cavity multicolor EC technology has only been around for a few years, it has enabled EC devices to achieve wide color hues, high brightness and high purity. EC devices based on F–P cavity have shown good applications in camouflage, 77 visual energy storage and 78 display devices, 6,71–76 filters, 79 etc .…”

Multicolored inorganic electrochromic materials: status, challenge, and prospects

“…11c). 107 The synergistic effect of multiple scattering of light by distributed pores in the nylon-66 film and the interference of the F–P cavity not only achieved larger coverage of color gamut, but also solved the angle-dependent coloring of the glass/WO 3 /W structure. Compared with current commercial color electronic readers and previously reported devices, this new idea was better in terms of visible angle, color gamut, wavelength modulation amplitude, and power consumption (Fig.…”