High-Temperature Resistance Photoluminescence Carbonized Polymer Dots Through Equilibrium Bi-Confinement Effects

Carbon dots are emerging luminescent nanomaterials that have drawn considerable attention due to their abundance, environmental friendliness, and customizable optical properties. However, their susceptibility to temperature-induced vibrational exciton changes and the tendency to thermal quenching of emission have hindered their practical applications. Here, a method is reported for achieving high-temperature photoluminescence carbonized polymer dots (CPDs) through a bi-confinement approach that involves a highly cross-linked polymer network and a rigid Al₂O₃ matrix. As the temperature increased from 303 to 500 K, the fluorescence and phosphorescence emission intensities of CPDs@Al₂O₃ remained virtually unchanged, with the emission duration exceeding 150 h at 500 K. Additionally, CPDs@Al₂O₃ composites with different degrees of carbonization exhibit dynamic excitation-dependent photoluminescence properties, which can be patterned for multiple information encryption application. This work provides a concept for designing stable and luminous CPDs under harsh conditions, thus expanding their potential application range.