Ultrafast All-Solid-State Electrochromic Devices for Multicolor Displays.

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 TiO2-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 (ΔT = 65.1%), an exceptionally high coloration efficiency (708.9 cm2/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.