Broadband Excitation from X‐Ray to UV for Afterglow Emission in Monodisperse Lanthanide‐Doped Nanoengineered Molecular Nanotransducers

Abstract

Abstract The rational design of uniform afterglow nanoparticles (NPs) is critical for applications such as bioimaging and information storage. However, excitation of afterglow NPs remains largely limited to either X‐ray or UV light. Integrating both X‐ray‐ and UV‐responsive afterglow components into a single NP platform remains a major challenge. Here, a broadband excitation strategy (X‐ray to UV) is reported for afterglow emission using lanthanide‐doped nanoengineered molecular nanotransducers. A 4‐phenylpyridine (4‐PP)‐doped SiO 2 shell is grown on NaLuF 4 :Tb(15 mol%)@NaYF 4 NPs. The SiO 2 shell is first coated onto the core, then functionalized via hydrothermal reaction with 4‐PP. Hydrogen bonding and physical interactions between 4‐PP and the SiO 2 matrix enable blue afterglow emission at 472 nm with a 2.41 s lifetime under 290 nm excitation. Under X‐ray excitation, high‐energy photons induce defect formation in the NaLuF 4 :Tb 3+ core, where stored energy is transferred to Tb 3+ ions, producing green afterglow with a persistence time exceeding 600 s. This dual‐mode excitation expands the operational versatility of afterglow materials. This approach demonstrates a promising strategy for integrating multiple optically active components into a single core–shell NP structure, offering tunable and extended afterglow performance for advanced optoelectronic and imaging applications.