A Novel Near-Infrared Emitting Sr₂LuSbO₆:Fe³⁺ Phosphor with Persistent Luminescence Performance

The near-infrared (NIR) persistent luminescence (PersL) materials have attracted widespread attention owing to the unique self-sustained light with good penetrability. Currently, most of the reported NIR PersL materials are activated by Cr3+. Considering the potential toxicity of chromium ions, there is an urgent requirement to explore the Cr3+-free NIR phosphors. Herein, a novel NIR phosphor Sr2LuSbO6:Fe3+ (SLSO:Fe3+) is prepared and its luminescence properties are systematically studied. The Fe3+-activated Sr2LuSbO6 exhibits a long-wavelength NIR emission band centered at 890 nm with a 110 nm full-width at half maximum (FWHM), and its PersL can last over 18 h. The phosphor shows excellent PersL stability even after being dispersed in solutions of different environments for 7 days. Furthermore, the PersL emitted by the phosphor can penetrate the 2 cm thickness beef, evidencing its good NIR PersL penetration property. This work provides a novel NIR PersL materials based on Fe3+ luminescence for technological applications and also contributes to accelerate the development of new-generation Fe3+-doped NIR PersL phosphor toward versatile applications.