Long-lasting ultraviolet-A persistent luminescence and photostimulated persistent luminescence in Bi3+-doped LiScGeO4 phosphor

Abstract

Persistent phosphors emitting in the ultraviolet (UV) spectral region have attracted great attention in recent years, owing to their promising potential in many advanced applications ranging from photocatalysis to phototherapy. Here, we report the development of a novel UVA emissive persistent phosphor by doping Bi³⁺ into a LiScGeO₄ host. The LiScGeO₄:Bi³⁺ persistent phosphor can be effectively charged using a standard 254 nm UV lamp and emits intense, long-lasting persistent luminescence peaking at 365 nm for longer than 120 h. Besides, the UVA persistent luminescence from the pre-irradiated LiScGeO₄:Bi³⁺ phosphor can be repeatedly rejuvenated by short-time photostimulation with low-energy white, red and near-infrared (NIR) light. The long-lasting UVA afterglow, together with the photostimulated persistent luminescence (PSPL) capability, makes the LiScGeO₄:Bi³⁺ phosphor an important element of persistent luminescence materials in the UVA spectral region. This UVA persistent phosphor is expected to find exciting applications in the fields of medical therapy and environmental research.