Realizing Simultaneous UV and Visible Persistent Luminescence by Defect Engineering

Multiband persistent luminescent materials offer distinctive opportunities for advanced optical information technologies by enabling time-resolved and spectrally encoded signal expression. However, most multiband persistent luminescent systems reported so far are restricted to the visible and near-infrared regions, while the incorporation of ultraviolet (UV) afterglow remains highly challenging despite its intrinsic advantages in concealment and background-free readout. In this work, a defect-assisted dopant engineering strategy is developed by introducing Gd³⁺ into CaF₂/Tb³⁺, enabling the simultaneous generation of UV and visible persistent luminescence within a single wide-bandgap fluoride host. Further investigations reveal that Gd³⁺ codoping induces abundant vacancy-related traps with suitable depth, which effectively facilitate charge storage and controlled release, while simultaneously acting as UV emission centers coupled with Tb³⁺-based visible emission. As a result, stable UV-visible dual-band afterglow is achieved, in which Gd³⁺-related UV emission and Tb³⁺-based visible emission coexist and can be selectively accessed for multichannel optical information storage and anticounterfeiting applications. More importantly, this work provides a feasible design strategy for incorporating UV emission into persistent luminescent systems, which is expected to promote the development of multiband long-lasting emissive materials spanning UV to near-infrared spectral regions.