Er^(3+)/Tm^(3+)分区掺杂结构的比率型光子上转换低温探针

Ratiometric Photon-upconversion Cryometer Based on Er^(3+)/Tm^(3+)Partition Doped Nanostructure

利用溶剂热法制备了六角相NaYF_(4)∶20%Yb,2%Er@NaYF_(4)@NaYbF_(4)∶0.5%Tm@NaYF_(4)多层核壳结构稀土掺杂上转换纳米粒子,研究其在低温场(10~295 K)及980 nm激发下分别来自于Er^(3+)的绿色与红色以及Tm^(3+)的蓝色发光的上转换发光性质。结果显示,绿光强度随温度升高呈现出先增后降的变化趋势,而蓝光强度随温度升高呈现热衰减的趋势。本工作利用发光强度比的测温方法实现了精准的温度测量,相对灵敏度可达3.2%·K^(-1)。并通过改变外层发光壳层的厚度调节发光强度比,进一步应用于低温场光学防伪。

Hexagonal phase NaYF_(4)∶20%Yb,2%Er@NaYF_(4)@NaYbF_(4)∶0.5%Tm@NaYF_(4) lanthanide-doped nano⁃particles with the core@multishell structure were synthesized by solvothermal method.The upconversion luminescence(UCL)properties of the materials at temperature from 10 K to 295 K were studied under 980 nm excitation.Green and red UCL from Er^(3+)and blue UCL from Tm^(3+)were observed in the visible light range.The luminescence intensity of green UCL first increased and then decreased,while the luminescence intensity of blue light showed a thermal attenuation trend with the temperature increase.The method of temperature-dependent luminescence intensity ratio(LIR)can be used in accurate temperature measurement,and the relative sensitivity is up to 3.2%·K^(-1).With various thicknesses of the outer luminescent shell,the different tendencies of LIR can be realized,which can be applied to cryogenic field anticounterfeiting.