Ambient light stimulation enabling intense and long-lasting ultraviolet-C persistent luminescence from Pr3+-doped YBO3 in bright environments

Abstract

Photostimulated luminescence (PSL) materials have attracted considerable attention in many important fields, varying from radiation dosimetry and biomedical imaging to security encryption and optical data storage. Nevertheless, monochromatic light illumination is usually used as the stimulus source to realize the absolute separation between the PSL signal and the excitation light. Furthermore, a dark environment is considered necessary to get rid of the interference from polychromatic ambient light. Herein, we report a glow-in-the-daylight material, YBO₃:Pr³⁺, which can emit intense and long-lasting ultraviolet-C (UVC) persistent luminescence in a bright indoor lighting or outdoor sunlight environment after ceasing X-ray excitation. We note that although the YBO₃:Pr³⁺ phosphor shows very weak UVC afterglow in darkness, remarkable enhancement of UVC persistent luminescence can be observed in a bright ambient light environment. The UVC persistent luminescence peaking at 274 nm can last for more than 24 h under the illumination of 900 lux white LED light, and the UVC luminescence signal is free from the interference of the ambient light. This enhancement of UVC persistent luminescence is assigned to the continuous and efficient photostimulation of polychromatic ambient light, which has been confirmed by comprehensive spectroscopic investigations. The appealing glow-in-the-daylight phenomenon from the YBO₃:Pr³⁺ phosphor will not only lay the foundation to develop more UVC persistent phosphors suitable for working in a bright environment, it will also promote the widespread use of these storage phosphors across a broad range of applications such as microbial inactivation and optical tagging.