Temperature-regulated evolution of carrier transport driving near-infrared persistent luminescence in Fe3+-activated olivine material

Near-infrared persistent luminescent (NIR PersL) materials, owing to the advantages of persistent emission and elimination of biological tissue autofluorescence, have garnered substantial research interest in bioimaging and biomedical fields. Nevertheless, high-performance NIR PersL materials remain scarce, which limits the applications of NIR PersL. Herein, we have developed a novel Fe 3+ -activated olivine-type PersL material, Li 2 ZnGeO 4 :Fe 3+ (LZGO:Fe 3+ ), which exhibits NIR PersL at around 770 nm. The representative sample LZGO:0.1%Fe 3+ has a duration exceeding 10 h after 254 nm light excitation. First-principles calculations demonstrate that Fe 3+ preferentially occupies Ge 4+ sites, and the main electron trap mediating the PersL is the oxygen vacancy. Additionally, by analyzing the temperature-dependent PersL decay curves across a wide temperature range (80–460 K), we have elucidated the relationship between electron transport processes and temperature, thereby refining the mechanistic framework of PersL under dynamic conditions. The potential applications of LZGO:Fe 3+ in bioimaging are explored and demonstrated. This work is anticipated to drive the research of NIR PersL materials toward versatile bioapplications.