摘要
Lanthanide-based luminescent anti-counterfeiting materials are widely used in various kinds of products.However,the emission color of traditional lanthanide-based luminescent materials usually remains nearly unaltered upon different excitation lights,which may only work for single-level anti-counterfeiting.Herein,the NaYbF4∶2%Er@NaYF4 core/shell nanoplates (NPs) with "chameleon-like" optical behavior are developed.These NPs display single-band red or green downshifting (DS) emission upon excitation at 377 or 490 nm,respectively.Upon 980 nm excitation,the color of upconversion (UC) emission can be finely tuned from green to yellow,and to red with increasing the excitation power density from 0.1 to 4.0 W/cm^2.The proposed materials readily integrate the advantages of excitation wavelength-dependent DS single-band emissions and sensitive excitation power-dependent UC multicolor emissions in one and the same material,which has never been reported before.Particularly,the proposed NPs exhibit excellent performance as security labels on trademark tag and security ink on painting,thus revealing the great potential of these lanthanide-doped fluoride NPs in multilevel anti-counterfeiting applications.
基金
the National Natural Foundation of China (NSFC)(Nos.21771185,51672272,21650110462,and U1805252)
the Strategic Priority Research Program of the CAS (No.XDB20000000)
the CAS/SAFEA International Partnership Program for Creative Research Teams
Natural Science Foundation of Fujian Province (No. 201710018).
作者简介
correspondence to:Datao Tu.dtt@fjirsm.ac.cn;correspondence to:Xueyuan Chen.xchen@fjirsm.ac.cn.
