通过共价固定调控单重态-三重态能隙实现碳点热刺激响应动态余辉OA

Integrating stimuli-responsive luminescence with dynamic emission properties offers a powerful strategy to enhance information encryption through multi-level authentication systems.By rationally tuning the singlet-triplet energy gap(ΔEST)of a material,simultaneous activation of phosphorescence(Phos)and delayed fluorescence(DF)can be achieved,enabling programmable dynamic afterglow behavior.In this work,we report the first carbon dot(CD)-based thermoresponsive dynamic afterglow material,synthesized via in situ covalent immobilization of CDs within a cyanuric acid matrix.The resulting system demonstrates a thermally driven green-to-blue afterglow transition across a wide temperature range(273.15-423.15 K),exhibiting dual-mode thermochromic afterglow(TCA)and time-resolved afterglow(TRA)characteristics.Notably,a blue-to-green afterglow transition occurs above the threshold temperature of 348.15 K,where TRA dominates due to temperature-dependent exciton redistribution.This synergistic TCA-TRA interplay endows the material with unprecedented dynamic afterglow modulation capabilities.Structural and photophysical analyses confirm that covalent fixation reduces the ΔEST of CDs from 0.46 to 0.28 eV,as designed.This ΔEST engineering enables thermal control over the Phos/DF equilibrium,directly governing the observed dynamic emission.Finally,the potential applications of the prepared material in thermal monitoring and high-security information protection are also demonstrated.