Multicolor luminescence of hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) microcrystals with tunable morphology under 940 nm excitation for temperature-responsive anti-counterfeiting

作     者：Lingna Xu Hongyan Zheng Tao Pang Junwen Mao Lingna Xu;Hongyan Zheng;Tao Pang;Junwen Mao

作者机构：College of ScienceHuzhou UniversityHuzhou 313000China 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2022年第40卷第3期

页      面：406-414,I0002页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 08[工学] 0708[理学-地球物理学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 

基　　金：Project supported by the National Natural Science Foundation of China(11575059) Natural Science Foundation of Huzhou City(2018YZ08)。 

主　　题：Upconversion luminescence Color regulation Anti-counterfeiting Rare earths 

摘      要：In this study,the hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) microcrystals were synthesized controllably,and upconversion luminescence excited at 940 nm and its application in temperature-responsive anti-counterfeiting are reported.It is clarified that the Ln^(3+)(Ln=Y+Yb+Ho+Ce)density ratio of bottom plane to side plane in the unit cell can be regulated by Ce^(3+) doping.It is also proved that the energy transfer of Yb^(3+) to Ho^(3+) is responsible for the activation of Ho^(3+)under 940 nm excitation,while the cross relaxation between Ho^(3+)and Ce^(3+)participates in the redistribution of electron population of^(5)S_(2)/^(5)F_(4)and^(5)F_(5)levels.Both theory and experiment confirm that the intensity ratio of red to green emission(I_(R)/I_(G))as a function of temperature as an independent variable has good linear characteristics in the temperature range of 300-500 K.Due to the good responsiveness of multicolor luminescence to temperature,the hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) with tunable morphology is a promising candidate for advanced temperature-responsive upconversion anti-counterfeiting.Our results provide a new pathway for the controllable synthesis of hexagonal NaYF_(4)microcrystals as well as the regulation of upconversion luminescence that is excited by wavelengths other than 980 nm and its application in anti-counterfeiting.