Dual-Mode, Color-Tunable, Lanthanide-Doped Core–Shell Nanoarchitectures for Anti-Counterfeiting Inks and Latent Fingerprint Recognition

Abstract

With the rapid development of information in modern society, the research and development of advanced anti-counterfeiting technology is becoming more and more important to protect the security and comprehensiveness of information. Therefore, fluorescent ink as an anti-counterfeiting technology and fingerprint recognition technology as a ″human information identification card″ has attracted the attention of many research groups. Herein, dual-mode (upconversion and downconversion) lanthanide-doped luminescent nanoarchitectures were developed using Y 2 O 3 :Er 3+ ,Yb 3+ nanoparticles as a core and layered lanthanide hydroxides nanomaterials as a shell. Under the irradiation of 980 nm near-infrared light, the nanoarchitectures emitted a bright upconverted red light emission. Meanwhile, under the irradiation of 254 nm UV light, the nanoarchitectures can directly emit multicolor luminescence (from green to yellow-green, yellow, orange, and red) by changing the suitable ratios of Tb 3+ / Eu 3+ ions. The information can only be extracted when the irradiation of two kinds of excitation light sources existed at the same time, which can improve the difficulty of illegal imitation and enhance the level of anti-counterfeiting. Furthermore, these luminescent nanoarchitectures were investigated for visual latent fingerprint recognition on various substrates with high definition, high sensitivity, and high antiinterference. These results indicated that the nanoarchitectures reported in this study may have great application prospects in information security and identity recognition.

Multimodal Luminescent Yb3+/Er3+/Bi3+‐Doped Perovskite Single Crystals for X‐ray Detection and Anti‐Counterfeiting

“…Presently, the realization of concurrent upconversion (UC) and DS have been successfully utilized in anti‐counterfeiting based on the lanthanide‐based dopants. [ 6–9 ] The Eu‐doped down‐shift luminescent materials have been applied in the Euro banknotes, which enables the visible photoluminescence (PL) based on UV lamp excitation. Meanwhile, the Bank of China also introduced the Yb/Er‐doped UC phosphors in the banknotes as the counterfeiting technique, which emits the yellow UC luminescence by the irradiation of 980 nm laser.…”

Luminescence anti‐counterfeiting: From elementary to advanced

“…Compared with single‐level luminescence anti‐counterfeiting, double‐level luminescence anti‐counterfeiting is a more advanced luminescence anti‐counterfeiting mode, in which the anti‐counterfeiting labels will change twice under the regulation of external stimuli and luminescence lifetime, substantially promoting anti‐counterfeiting level. Based on the category of regulation factors, the double‐level luminescence anti‐counterfeiting can be divided into three types: (1) regulated by excitation light; [ 17,37–44 ] (2) co‐regulated by excitation light and luminescence lifetime; [ 45–58 ] (3) co‐regulated by excitation light and other factors (e.g., heat, chemical reagents, and mechanical force). [ 59–61 ]…”

Aerosol synthesis of TiO2:Er3+/Yb3+ submicron-sized spherical particles and upconversion optimization for application as anti-counterfeiting materials

“…[10][11][12] In particular, the security technology using UC properties of rare earth doped materials can be distinguished from the existing anti-counterfeiting technology using UV-based DC materials and can be used as a new security technology. [13][14][15] Red, green and blue up-conversion can be achieved in a variety of matrixes using Er 3+ , Ho 3+ and Tm 3+ as activators and Yb 3+ as deactivators. [16][17][18] The most commonly used host material is a uorine compound such as NaYF 4 .…”