450 nm Photon‐Pumped Ultraviolet‐C Luminescence for Multifunctional Applications

Abstract With the implementation of the Minamata Convention on Mercury, there is an urgent need to find a new way to generate ultraviolet‐C (UVC) light to replace mercury lamp. Upconversion phosphors have the potential to generate UVC light as they are able to convert low energy photons into high energy emissions. Here a new Sr 2 SiO 4 :Pr 3+ phosphor is reported that could emit UVC light under excitation of a commonly used 450 nm laser diode, a cheap blue light‐emitting diode (LED) with central emitting wavelength at 450 nm, and even sunlight. Moreover, the potential applications of the UVC light of Sr 2 SiO 4 :Pr 3+ phosphor upon excitation at 450 nm are demonstrated in several different situations, including static marking and dynamic tracking. Demonstration of the unique advantage of photon‐upconverted UVC emission of Sr 2 SiO 4 :Pr 3+ in the application of sterilization is mainly focused, especially when the deep ultraviolet (DUV) LED cannot work adequately. This work opens a new route for generating UVC light and expands the applications of photon‐upconverted UVC emission, which is expected to be an indispensable supplement to the deep ultraviolet LED.