Near-Infrared-Excitable Organic Ultralong Phosphorescence through Multiphoton Absorption

摘要

Organic ultralong room-temperature phosphorescence(OURTP)with a long-lived triplet excited state up to several seconds has triggered widespread research interests,but most OURTP materials are excited by only ultraviolet(UV)or blue light owing to their unique stabilized triplet-and solid-state emission feature.Here,we demonstrate that near-infrared-(NIR-)excitable OURTP molecules can be rationally designed by implanting intra/intermolecular charge transfer(CT)characteristics into Haggregation to stimulate the efficient nonlinear multiphoton absorption(MPA).The resultant upconverted MPA-OURTP show ultralong lifetimes over 0.42 s and a phosphorescence quantum yield of~37%under both UV and NIR light irradiation.Empowered by the extraordinary MPA-OURTP,novel applications including two-photon bioimaging,visual laser power detection and excitation,and lifetime multiplexing encryption devices were successfully realized.These discoveries illustrate not only a delicate design map for the construction of NIR-excitable OURTP materials but also insightful guidance for exploring OURTP-based nonlinear optoelectronic properties and applications.