Nature‐Inspired Flexible Electrochromic and Electrofluorochromic Displays: A Dual Bistable Multicolor System Based on Proton‐Coupled Electron Transfer of Leuco Dyes

Abstract Bistable electrochromic displays offer great potential due to their ability to maintain both colored and colorless states while minimizing power consumption and saving energy. In this research, the electrochromic properties of organic small molecular leuco dyes are explored. Various displays are fabricated using crystal violet lactone, cresol red, fluorescein, and rhodamine b derivatives, based on the proton‐coupled electron transfer mechanism. Considering the switching time and bistability, prototype devices such as anti‐counterfeiting displays, gate displays, e‐papers, multi‐color displays, colorful displays, and nature‐inspired flexible displays are developed. Electrochromic devices based on bond cleavage/formation of leuco dyes exhibit outstanding color efficiency (min: 206 cm 2 c −1 , max: 1163 cm 2 c −1 ), rapid switching (min: 0.1 s, max: dynamic responsivity), dual outputs (color and emission), and reversibility (150–200 cycles). The nature‐inspired flexible displays with strong electrochromic color memory and multicolor responsiveness offer new possibilities for utilizing organic leuco dyes in the design and fabrication of electrochromic devices.