Thermal-responsive multicolor emission of single NaGdF4:Yb/Ce/Ho upconversion nanocrystals for anticounterfeiting application

Nanophotonics

Hu Yanqing¹  Jiang Jianqing¹  Shao Qiyue¹  Deng Xinyi¹ 

[1] School of Materials Science and Engineering, Jiangsu Key Laboratory for Advanced Metallic Materials, Southeast University, Nanjing, 211189, PR China;

关键词: anticounterfeiting;    luminescence;    nanocrystals;    quenching;    upconversion;   

DOI  :  10.1515/nanoph-2020-0136

来源: DOAJ

【 摘 要 】

This study presents a novel and high-level anticounterfeiting strategy based on Ce/Yb/Ho triply-doped NaGdF4 nanocrystals with temperature-responsive multicolor emission. A critical factor leading to the multicolor emission is confirmed by comparing the luminescence thermal behaviors of nanocrystals in various atmospheres. Through analyzing the temperature-dependent lifetimes of Yb3+ ions in air, we demonstrate that thermally-induced multicolor emission mainly originates from the gradually-attenuated H2O quenching effect. Because the cross-relaxations between Ce3+ and Ho3+ ions and the nonradiative transitions of Yb3+ ions create plenty of phonon heat, the multicolor emission of nanocrystals can be achieved under 975 nm excitation at a relatively low power density. This recognition method is efficient and convenient for security authentication. The as-synthesized core nanocrystals can be directly used to fabricate anticounterfeiting ink without further processing (e.g. core/shell or hybrid). Therefore, the small-sized β-NaGdF4:Yb/Ce/Ho nanocrystals are promising candidate for security application.

【 授权许可】

Unknown