Journal Article

X-ray-activated long persistent phosphors featuring strong UVC afterglow emissions

Jun-Ying, Zhang, Zhao, Qing, Li-Yan, Zhang, Zi-Jun, Yong, Wang, Xin, Li, Zhi-Yong, Ju-Ping, Ma, Yan-Min, Yang, Li-Rong, Zheng, Lu, Yue, Kuroiwa, Yoshihiro, Li, Hong, Moriyoshi, Chikako, Shao-Qiang, Guo, Hong-Tao, Sun, Li-Li, Hu

2018

Overview

Phosphors emitting visible and near-infrared persistent luminescence have been explored extensively owing to their unusual properties and commercial interest in their applications such as glow-in-the-dark paints, optical information storage, and in vivo bioimaging. However, no persistent phosphor that features emissions in the ultraviolet C range (200–280 nm) has been known to exist so far. Here, we demonstrate a strategy for creating a new generation of persistent phosphor that exhibits strong ultraviolet C emission with an initial power density over 10 milliwatts per square meter and an afterglow of more than 2 h. Experimental characterizations coupled with first-principles calculations have revealed that structural defects associated with oxygen introduction-induced anion vacancies in fluoride elpasolite can function as electron traps, which capture and store a large number of electrons triggered by X-ray irradiation. Notably, we show that the ultraviolet C afterglow intensity of the yielded phosphor is sufficiently strong for sterilization. Our discovery of this ultraviolet C afterglow opens up new avenues for research on persistent phosphors, and it offers new perspectives on their applications in terms of sterilization, disinfection, drug release, cancer treatment, anti-counterfeiting, and beyond.

• Publisher: Springer Nature B.V
• Subject: Cancer / Disinfection / Information storage / Sterilization