A straightforward approach for high-end anti-counterfeiting applications based on NIR laser-driven lanthanide doped luminescent glasses

Abstract

Emission color tuning of Ho3+/Tm3+/Yb3+ doped glass patterns via focusing and defocusing the laser beam.

Dual-color dynamic anti-counterfeiting labels with persistent emission after visible excitation allowing smartphone authentication

“…This level is widely used in certificates and currencies, although relatively susceptible to counterfeit reproduction 7 . The single-level luminescence anti-counterfeiting can use down-shifting (DS) photoluminescence 8 , 9 up-conversion (UC) photoluminescence 10 – 12 , chemiluminescence 13 , or mechanoluminescence 14 – 16 features of phosphor materials. Dual-level luminescence-based anti-counterfeiting tags extend upon the single-level tags in that the observable covert and overt features are parameterized and quantified in terms of both the stimuli and the observed stimuli responses.…”

Recyclability of CsPbBr3 quantum dot glass nanocomposites for their long-standing use in white LEDs

“…Decay profiles are obtained under excitation of a 450 nm picosecond laser having a 81.7 ps pulse width (model: Edinburgh instruments EPL-450) via a time-correlated single photon counting (TCSPC) technique. The recorded decay curves are fitted using a bi-exponential equation according to the following formula: 32 where, I ( t ) is defined as the emission intensity, A 1 and A 2 are the decay constants and τ 1 and τ 2 are the luminescence lifetime values. The average lifetime values are calculated through the following equation: 33 …”

Chiral Luminescent Liquid Crystal with Multi‐State‐Reversibility: Breakthrough in Advanced Anti‐Counterfeiting Materials

“…The development of anti-counterfeiting materials has attracted particular attention in order to prevent the increasing counterfeits on the current market, including brands, luxury items, banknotes, tickets, and certificates. [1][2][3][4][5][6][7][8][9] In the past few decades, a DOI: 10.1002/advs.202201565 wide variety of security and anticounterfeiting technologies have been developed, including thermal, [10][11][12][13] magnetic, [14] light, [15][16][17] and mechanical responses. [18,19] Therein, the single-mode (photoluminescence or reflective color) with single-state (only one reflective color or fluorescence) is the most widely used, possessing the advantages of a broad range of materials sources, easy operation, and observation.…”