Preparation and characterization of NaYF_4:Er^(3+),Tm^(3+)@NaYF_4:Ce^(3+),Tb^(3+) microcrystals with dual-mode emissions at the single-particle level  

作　　者：Xianfu Jiao Weihao Ye Qiying Huang Jie Luo Linliang Yu Xiaotang Liu 

机构地区：[1]Guangdong Engineering Technology Research Center for Optical Agriculture,College of Materials and Energy,South China Agricultural University,Guangzhou 510642,China

出　　处：《Journal of Rare Earths》2020年第7期697-704,I0001,共9页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (21271074,51372091);the Teamwork Projects funded by the Guangdong Natural Science Foundation (S2013030012842);Guangdong Provincial Science&Technology Project (2015B090903074);Guangzhou Science&Technology Project (201605030005)。

摘　　要：Under hydrothermal environment,we synthesized lanthanide ions doped sodium yttrium fluoride(NaYF4:Er,Tm@NaYF4:Ce,Tb) luminescent microcrystals via an epitaxial growth technique.The structure and morphology of these microcrystals were examined by SEM,TEM,EDS and XRD measurements.These particles show dual-mode emissions with red upconversion(UC) and green down conversion(DC) as single particles level.The mean length and diameter of these microparticles increase from 0.43 to2.26 μm and from 1.33 to 1.86 μm,respectively.Most interestingly,the photoluminescence properties of NaYF4:Er,Tm@NaYF4:Ce,Tb phosphor crystals are highly dependent on the crystallite size.The microcrystals fluoresce emit dual-mode emissions when they are solid or dispersed in solvents.Benefiting its intensive fluorescence and uniform morphology,these materials hold great potential for security and anti-counterfeiting applications.

关 键 词：NaYF4 microcrystals Dual-mode fluorescence materials Single-particles CORE-SHELL HYDROTHERMAL Rare earths 

分 类 号：TB34[一般工业技术—材料科学与工程]