Manipulation of Photo‐Active Ultralong Organic Phosphorescence in Host‐Guest System

Abstract The photo‐active ultralong organic phosphorescence (UOP) materials can only emit UOP gradually under consistent UV irradiation, which is primarily attributed to internal quenching of triplet oxygen, yet manipulating the rate of the photo‐activating process is seldom reported. In addition, amorphous small‐molecule doping UOP material is rarely reported either. In this study, a series of host and guest materials are synthesized and doped into amorphous UOP doping systems. These doping systems demonstrated a tunable photo‐activating rate (4–6 seconds to reach a saturated state), and the amorphous structure realized the sensitive detection of oxygen. The results affirm that triplet oxygen plays a pivotal role in determining whether UOP can be emitted, and importantly, it is established that a crystalline structure in small‐molecular doping systems is not a necessary condition. Furthermore, polymer‐based UOP materials, manufactured through co‐doping with both host and guest, exhibited tunable photo‐activating rates (4–16 s) and lifetimes (226.38–462.78 ms). To expand the application, the UV‐curing resin‐based UOP materials are prepared via 3D‐printing technology. This innovative work introduces a new approach for applying UOP materials in the field of amorphous doping system, providing a guiding strategy for widespread applications in oxygen detecting, time‐resolved information display and dynamic multi‐dimensional anti‐counterfeiting.