An Advanced Tunable Multimodal Luminescent La₄GeO₈: Eu²⁺, Er³⁺ Phosphor for Multicolor Anticounterfeiting

Abstract

The development of advanced luminescent materials is of great importance to the anticounterfeiting application and still confronts with lots of challenges. At present, most anticounterfeiting luminescent materials are based on a monotonous photoluminescence model, which is easily faked by substitutes. Therefore, in this work, a multimodal La4GeO8: Eu2+, Er3+ material is reported, which can emit red, purple, baby blue, and green light under the increased excitation wavelength from 250 to 380 nm. Meanwhile, the phosphor also shows green upconversion luminescence under the NIR (980 and 808 nm) laser irradiation. Moreover, the phosphor features excellent stability and humidity resistance against harsh conditions. Based on the integrated feature, a functional anticounterfeiting application is designed. Results demonstrate that the multimodal luminescent feature can be easily detected by using a portable ultraviolet lamp or NIR (808 or 980 nm) laser. The unique characteristic will be complicated to counterfeit and show high‐level security in the field of advanced anticounterfeiting.

Lanthanide-doped heterostructured nanocomposites toward advanced optical anti-counterfeiting and information storage

“…Figure 2a displays a model that illustrates the energy transfer processes of Eu 2+ to Eu 3+ and the characteristic f–f transition emission of Eu 3+ in the nanocomposite. The emission of Eu 2+ and Eu 3+ will be competing under UV light irradiation when Eu 2+ and Eu 3+ coexist in the nanocomposites 43 , 44 . As presented in Fig.…”

A multicolor-switchable fluorescent lanthanide MOFs triggered by anti-cancer drugs: multifunctional platform for anti-cancer drug sensing and information anticounterfeiting

“…Anticounterfeiting techniques exhibit great potential in security fields ranging from economy, military, and politics because counterfeiting has serious threats to the safety of these fields. 13 It is worth mentioning that anticounterfeiting technologies based on fluorescence have been widely used and seen as the best candidate in various encoding fields, benefiting from its unique visual effect. 14 Optical anticounterfeiting security labels based on various types of materials, such as luminescent quantum dots, metal–organic frameworks, and up-converting nanocrystals have been reported.…”

Photoluminescence and Energy Transfer in Double- and Triple-Lanthanide-Doped YVO4 Nanoparticles

“…First, they are characterized by the stability of the physical and chemical behavior over a wide temperature range, biocompatibility, and mechanical hardness. The combination of these properties makes them promising candidates for a wide range of applications in mechanical engineering [ 14 , 15 , 16 ], medicine [ 17 , 18 ], sensing technology [ 19 , 20 ], anticounterfeiting [ 21 , 22 ], and others [ 23 , 24 ].…”