Ultrafast All‐Solid‐State Electrochromic Devices for Multicolor Displays

ABSTRACT All‐solid‐state electrochromic devices (ASSECDs) hold tremendous potential for emerging display technologies. However, achieving sufficiently fast switching for modern display applications remains a significant challenge. Herein, we report an interfacial engineering strategy that synergistically optimizes both electron transfer and ion compensation processes to realize ultrafast‐response ASSECDs. Through surface immobilization of rationally designed dual‐chromophore extended viologen derivative 2BTB‐2POH on TiO 2 ‐modified electrodes combined with a succinonitrile‐based solid‐state electrolyte, the device achieves unprecedented response times of 0.16 s for coloration and 0.40 s for bleaching, representing the fastest switching speeds reported to date for all‐solid‐state electrochromic systems. Furthermore, the device demonstrates a high optical contrast (Δ T = 65.1%), an exceptionally high coloration efficiency (708.9 cm 2 /C), and robust cycling stability (>10,000 cycles with 91.1% retention). By rationally tuning the chromophore structure of viologens ( 2BBAr‐2POH and 2BTD‐2POH ), we extend this strategy to multicolor systems covering a red‐green‐blue (RGB) primary‐color demonstration, and successfully fabricate patterned display prototypes with dynamic display demonstrations. This work establishes a viable pathway toward high‐performance ASSECDs for next‐generation display applications.