Zhou Xinquan, Qiao Jianwei, Zhao Yifei, Han Kai, Xia Zhiguo
The State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, School of Materials Science and Technology, South China University of Technology, Guangzhou, 510641 China.
School of Physics and Optoelectronics, South China University of Technology, Guangzhou, 510641 China.
Sci China Mater. 2022;65(4):1103-1111. doi: 10.1007/s40843-021-1790-1. Epub 2021 Oct 15.
Perusing multimode luminescent materials capable of being activated by diverse excitation sources and realizing multi-responsive emission in a single system remains a challenge. Herein, we utilize a heterovalent substituting strategy to realize multimode deep-ultraviolet (UV) emission in the defect-rich host LiCaGeO (LCGO). Specifically, the Pr substitution in LCGO is beneficial to activating defect site reconstruction including the generation of cation defects and the decrease of oxygen vacancies. Regulation of different traps in LCGO:Pr presents persistent luminescence and photo-stimulated luminescence in a synergetic fashion. Moreover, the up-conversion luminescence appears with the aid of the 4 discrete energy levels of Pr ions, wherein incident visible light is partially converted into germicidal deep-UV radiation. The multi-responsive character enables LCGO:Pr to response to convenient light sources including X-ray tube, standard UV lamps, blue and near-infrared lasers. Thus, a dual-mode optical conversion strategy for inactivating bacteria is fabricated, and this multi-responsive deep-UV emitter offers new insights into developing UV light sources for sterilization applications. Heterovalent substituting in trap-mediated host lattice also provides a methodological basis for the construction of multi-mode luminescent materials.
寻找能够被多种激发源激活并在单一系统中实现多响应发射的多模发光材料仍然是一项挑战。在此，我们采用异价取代策略在富含缺陷的基质LiCaGeO（LCGO）中实现多模深紫外（UV）发射。具体而言，LCGO中的Pr取代有利于激活缺陷位点重构，包括阳离子缺陷的产生和氧空位的减少。对LCGO:Pr中不同陷阱的调控协同呈现出持续发光和光激发发光。此外，借助Pr离子的4个离散能级出现上转换发光，其中入射可见光部分转化为杀菌深紫外辐射。这种多响应特性使LCGO:Pr能够响应包括X射线管、标准紫外灯、蓝色和近红外激光在内的便捷光源。因此，构建了一种用于灭活细菌的双模光学转换策略，这种多响应深紫外发射体为开发用于杀菌应用的紫外光源提供了新的见解。陷阱介导的主体晶格中的异价取代也为构建多模发光材料提供了方法学基础。
