Enhancement of the Persistent Luminescence of SrAl ₂ O ₄ :Eu, Dy Ceramics Through Incorporation of Ag and Au Nanoparticles

Persistent luminescent materials are essential for advancing energy‐efficient lighting, bioimaging, and sensing technologies. However, improving their optical performance remains a key challenge. Here, the integrating of Ag and Au plasmonic nanoparticles (NPs) on the surface of consolidated SrAl 2 O 4 :Eu 2+ ,Dy 3+ ceramics enhances both photoluminescence intensity and the persistent afterglow through increasing the light concentration and charge transfer between the NPs and the luminescent matrix. The ceramics are sintered via hot isostatic pressing, achieving >99% theoretical density with controlled surface roughness optimized for nanoparticle deposition. Functionalization of plasmonic nanostructures is achieved through solid‐state dewetting of thin metallic films followed by thermal annealing. This process generates discrete NPs with strong localized surface plasmon resonances. Finite element simulations reveal a hole‐sphere‐like growth for plasmonic NPs after the solid‐state dewetting process, as well as a stronger local electric field enhancement around NPs at the excitation wavelength, correlating with experimental results. This work demonstrates an effective route for tailoring long‐persistent phosphors and offers new perspectives for the design of advanced optoelectronic materials.