Multilevel Static–Dynamic Anticounterfeiting Based on Stimuli-Responsive Luminescence in a Niobate Structure

Abstract

Anticounterfeiting is a highly required technique to protect the product and the consumer rights in the modern society. The conventional luminescent anticounterfeiting is based on downconversion luminescence excited by an ultraviolet light, which is easy to be faked. In this work, we realized six luminescent modes in a niobate-based structure (LiNbO3:RE3+, RE3+ = Pr3+, Tm3+, Er3+, Yb3+), in which photostimulated luminescence of LiNbO3:Pr3+, and upconversion luminescence color evolution of LiNbO3:Er3+ were first presented. Based on the above luminescent modes of LiNbO3:RE3+, multilevel anticounterfeiting devices were developed. By employing mechanoluminescence and persistent luminescence, we achieved dual-mode anticounterfeiting that could display the luminescent patterns without any direct irradiation. In addition, another dual-mode anticounterfeiting based on photostimulated luminescence and upconversion luminescence excited by a near-infrared light was realized, which could display the anticounterfeiting patterns in both static and dynamic states. To obtain an even higher anticounterfeiting level, downconversion luminescence, thermoluminescence, photostimulated luminescence, and upconversion luminescence were simultaneously applied in a food trademark. This four-mode anticounterfeiting trademark could not only show a static–dynamic luminescence that is hard to be faked but also allow consumers to distinguish the food freshness. The presented multilevel anticounterfeiting strategies could be employed to resolve the counterfeit issues in various fields.

Luminescence in Manganese (II)-Doped SrZn2S2O Crystals From Multiple Energy Conversion

“…While pursuing its state-of-the-art materials by realizing one mode of energy transformation, one single material that could efficiently transform multiple types of energy to light emission has entered people's vision. These materials may bring to life many new appealing applications in the interdisciplinary fields (Singh et al, 2011 ; Liu et al, 2018 ; Xu et al, 2018 ; Zhang et al, 2018b , 2020 ; Jiang et al, 2019 ; Sang et al, 2019 ).…”

Luminescence anti‐counterfeiting: From elementary to advanced

“…DC photoluminescence anti‐counterfeiting is realized by absorbing one high‐energy photon and releasing one low‐energy photon. [ 35 ] At present, the materials used in single‐level DC photoluminescence anti‐counterfeiting include organic luminogens, [ 19 ] graphene quantum dots, [ 21 ] Ln‐carbon quantum dots, [ 22 ] cellulose nanofibrils/CdTe quantum dots, [ 23 ] carbon and oxygen co‐doped hexagonal boron nitride, [ 24 ] nitrogen‐doped carbon dots, [ 25 ] carbon dots/Ln‐MOFs hybrids, [ 26 ] Ln‐metal organic frameworks (Ln‐MOFs), [ 29 ] Tb 3+ /Eu 3+ ‐grafted melamine cyanurate, [ 31 ] and SrAl 2 O 4 :Eu 2+[ 36 ] . As shown in Figure 2A, Gao et al.…”

Optically Stimulated Luminescence Phosphors: Principles, Applications, and Prospects

“…The energy levels of defects in the bandgap close to the CB minimum and VB maximum are regarded as electron and hole traps. The big and small [ 191] Tb 3+ , Hf 4+ 544 442 - [ 192] LiCaPO 4 Ce 3+ 369 Blue LED 0.6, 0.9 [ 193] LiNbO 3 Pr 3+ 620 980 - [ 194] Ca 4 Ti 3 O 10 Pr 3+ , Y 3+ 612 980 0.9-0.98 [ 195] LiTaO 3 Bi 3+ 430 808/980 0.55-1.16 [ 196] ZrO 2 -480 808/980 - [ 197] SrMoO 4 --470 0.9-1.95 [ 198] BeO Na + , Tb 3+ , Gd 3+ -470 - [ 199] Na + , Dy 3+ , Er 3+ 250 470 - [ 200] LiMgPO Tm 3+ 460 energy differences between the defect energy level and CB/VB differ the deep and shallow traps. [205,206] Though the incorporation of an activator can affect the intrinsic traps or even cause new traps, an effective way is to properly codope with a different ion to introduce the traps intentionally.…”