Ultralong and Thermally Enhanced Persistent Luminescence in Printable Recycled Polymers for Advanced Thermal Imaging

Abstract

Abstract Achieving long persistent luminescence (LPL) in fully organic materials with both hour‐level duration and high thermal stability remains a fundamental challenge attributable to rapid exciton quenching and poor resistance to thermal disturbances. Herein, a trap engineering strategy is reported based on rigidified triphenylamine derivatives and boronic ester functionalization embedded in recycled poly(ethylene terephthalate) (PET), enabling the first fully organic polymer‐based LPL system that exhibits simultaneously ultralong LPL and exceptional thermal robustness. Molecular conformation locking and optimized donor–acceptor charge transfer lead to deep trap states (≈1.03 eV), resulting in ambient LPL lifetimes exceeding 12 h. Remarkably, the luminescence is thermally enhanced by over 56 times at 500 K, rivaling high‐performance inorganic phosphors. In addition, 980 nm near‐infrared photo excitation further amplifies the emission, showcasing strong photo‐stimulated luminescence capability. Taking advantage of PET's processability, 3D‐printed luminescent structures are fabricated that retain LPL functionality and enable spatially resolved thermal sensing and real‐time damage detection. This work not only introduces a sustainable and scalable platform for advanced thermal imaging and optoelectronics, but also sets a new benchmark in the design of heat‐resistant organic LPL materials, bridging the gap between high‐performance functionality and environmental compatibility.