Proton‐Transfer Electrochromic Devices Capable of Red‐To‐Green Switching and Near‐Infrared Modulation for Camouflage Applications

Organic electrochromic materials offer significant potential for dynamic optical regulation in both the visible and near‐infrared regions, particularly for applications in intelligent camouflage and thermal management. Guided by the proton‐coupled electron transfer (PCET) mechanism, this study designed a pH‐responsive electrochromic system. The system utilizes p‐benzoquinone as an electrochemical base generator and a perylene diimide (PDI) derivative as a base‐responsive dye, constructing a reversible red‐to‐green switching electrochromic device with remarkable near‐infrared modulation capability. To address the poor film‐forming ability of the dye, polymethyl methacrylate (PMMA) was introduced to optimize the film‐forming process, and the mass ratio and electrochromic layer thickness were optimized. The resulting device achieved an absorbance modulation (ΔAbs.) of 0.84 at 778 nm, and a coloration efficiency of 143 cm 2 C −1 . Crucially, it retained over 90% of its initial performance after 2000 cycles. This study provides a viable material strategy for developing organic electrochromic devices with high stability and efficient near‐infrared modulation.