Room-Temperature White Persistent Luminescence from Dy3+-Doped LaAlO3 Nanophosphors

Abstract Achieving room temperature white persistent luminescence (PersL) remains challenging because most persistent phosphors exhibit monochromatic afterglow and rely on limited activators such as Eu2+ or Cr3+. Although Dy3+ ions can intrinsically produce white light through balanced blue (4F9/2 → 6H15/2) and yellow (4F9/2 → 6H13/2) emissions, they rarely show PersL in the LaAlO3 host due to the absence of suitable trap states capable of releasing charge carriers at ambient conditions. The difficulty is further amplified in nanophosphors, where a high surface-to-volume ratio introduces nonradiative surface defects that quench trapped carriers and suppress afterglow. Here, we demonstrate room temperature white PersL in Dy3+-doped LaAlO3 nanophosphors synthesized via a combined coprecipitation with molten salt synthesis route for the first time. This strategy enhances crystallinity while engineering a broad distribution of intrinsic shallow, intermediate, and deep traps that efficiently store and gradually release charge carriers, overcoming surface-related quenching. The optimized phosphor exhibits stable white afterglow lasting over 10 min at room temperature. Beyond PersL, the material also shows optically stimulated luminescence, thermally stimulated luminescence, and X-ray–activated PersL, confirming multimodal excitation capability. The coexistence of white afterglow and multistimuli responsiveness in Dy3+-activated perovskite nanophosphors establishes it as a promising platform for flicker-free solid-state lighting, radiation dosimetry, optical data storage, and anticounterfeiting applications.