Multicolor luminescence and triple-mode emission of simple CaTiO₃:Pr³⁺,Er³⁺particles for advanced anti-counterfeiting

Abstract

The multilevel anticounterfeiting QR code readily integrates the advantages of excitation wavelength-dependent PL emissions, a strong red afterglow and sensitive excitation power-dependent UCL emissions in one overall device.

Luminescent Erbium‐Doped Silicon Thin Films for Advanced Anti‐Counterfeit Labels

“…Such techniques can be based on radio frequency identification technology, [5] visible watermarks, [6] graphical barcodes, [7] holograms, [8] laser-written polymer features in liquid crystal devices, [9] images based on structural colors, [10,11] or photonic crystals, [12] etc. In addition, advanced anti-counterfeiting strategies based on information encoding through design of polymer-based molecular barcodes, [13] DNA, [14] invisible fluorescent "peptide coding" taggants, [15] physical unclonable functions utilizing fluorescence from quantum dots, [16] dyes, [17] or proteins, [18] far-field scattering of plasmonic nanomaterials, [19] multicolor luminescence of perovskite particles, [20] luminescent oxygen-sensitive ink, [21] or enhanced Raman scattering [22] as well as many other concepts are actively developed. Among all types of materials applied for security labels, luminescent ones attract especial interest.…”

An anticounterfeiting technology combining an InP nanoparticle ink and a versatile optical device for authentication

“…The amount of fluorescent material is the key factor to formulate ink. Generally, a high amount (5-25%) of fluorescent material was required to formulate ink 20,31,66,67 . However, significantly low…”

“…However, as these 5 materials often exhibit monochromatic emissions that are easy to imitate, these security inks offer a low level of protection against counterfeiting. In recent years, luminescent inks made of rareearth materials attract great attention due to their fast response time, high brightness, and efficiency [31][32][33][34] . However, rare-earth materials-based security inks severely limit scaled-up production due to high cost.…”

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

“…[ 4–6 ] Among them, the photochromic anticounterfeiting strategy has attracted extensive attention due to its advantages such as good concealment, difficult imitation, bright colors, and low cost. [ 7–10 ] As an anticounterfeiting material, excellent optical properties, good chemical stability, and humidity resistance are urgently needed to develop.…”