Ultrahigh‐Temperature Afterglow of Organic Materials via Traps Engineering

Abstract Organic materials with high‐temperature afterglow are critical for extreme‐environment applications but suffer from severe thermal quenching. In this paper, A trap engineering strategy to achieve ultrahigh‐temperature is proposed that afterglows even at 300 °C by integrating 2,2′‐biquinoline (BQ) emitters into a boronic acid (BA) matrix (BQ@BA). The BQ@BA system exhibits dual afterglow emissions at 480 and 600 nm, with the 480 nm emission dominating at elevated temperatures. The thermal compensation effect from the oxygen vacancies synergizes with temperature‐activated reverse intersystem crossing (RISC) to enable stable 480 nm delayed emission under extreme thermal conditions. Additionally, the trapping depths can be flexible modulated, successfully endowing the changes of the thermochromic afterglow behaviors. Finally, leveraging the temperature‐dependent spectral evolution of BQ@BA, A dynamic information encryption and anti‐counterfeiting prototypes is developed which, respond to thermal stimuli, showcasing their adaptability in harsh environments. This work provides a breakthrough in designing organic afterglow materials for high‐temperature applications and advances their practical deployment in advanced optical technologies.