Triple‐Responsive Visible‐To‐Ultraviolet‐C Upconverted Photons for Multifunctional Applications

Abstract Optically upconverted materials that are capable of converting long‐wavelength low‐energy photons into short‐wavelength high‐energy light have found their applications over a broad spectrum of fields, like light‐emitting diodes (LEDs), displays, bio‐detection, etc. Despite the great advances in exploring the conventional near‐infrared‐to‐visible or even near‐infrared‐to‐ ultraviolet upconverted materials, the visible‐to‐ultraviolet‐C counterparts are far from being desired. Here, a new triple‐responsive material is introduced, i.e., Pr 3+ ‐doped Li 2 SrGeO 4 . It has the ability to absorb the visible photons at ≈450 nm from LEDs, laser diodes (LDs), and even sunlight and emit the ultraviolet‐C (UVC) light covering the 240–280 nm wavelength range. Considering the unique characteristics of the UVC photon, the promising applications of the material are further demonstrated in several scenarios, including static/dynamic labeling under the excitation of a 450 nm LED, information encryption under excitation of sunlight, and sterilization under excitation of a 450 nm LD. The work enriches the library of optically upconverted visible‐to‐UVC materials and widens the application scenarios of these materials.