Recent Studies of Defects in Persistent Luminescent Materials

Persistent luminescent (PersL) materials, which continue emitting light after the excitation is ceased, have garnered significant attention for diverse applications. As trap centers, defects play a central role in enabling and modulating PersL by capturing and storing charge carriers (electrons or holes) during excitation. The type, depth, distribution, and density of these traps govern the release features and dynamics of charge carriers, and consequently dictate the wavelength, intensity, and duration of PersL. Despite extensive research on PersL, a comprehensive review specifically focusing on the role of defects is lacking. Herein, we provide an overview of the composition and mechanisms of PersL, followed by systematic explorations on the types of defects, common characterization methods, their impact on PersL performance, and defect engineering strategies for PersL optimization. After highlighting defect-guided design of persistent luminescent nanoparticles (PLNPs), advances in first-principles modeling of defects, and representative applications of PersL materials are summarized. We end with discussing current challenges and perspectives on defect control strategies toward high-performance PersL systems.