No‐Interference Reading for Optical Information Storage and Ultra‐Multiple Anti‐Counterfeiting Applications by Designing Targeted Recombination in Charge Carrier Trapping Phosphors

Abstract

Charge carrier trapping phosphors are one of the most fascinating candidates for next‐generation optical information storage technology and advanced anti‐counterfeiting applications. However, there is a challenge in that shallow traps can result in interference with the real‐time reading of optical information, and the anti‐counterfeiting level also needs to be further enhanced. Here, a novel quasi‐layer‐structured Ca3Ga4O9:Bi3+ phosphor is introduced to address this challenge, based on the targeted recombination phenomenon. This material shows turning electron‐trapping ability and obvious differences in photoluminescence, long persistent luminescence, and photo‐stimulated luminescence processes, which are beneficial in achieving information reading without interference and provide multiple anti‐counterfeiting. As a proof of concept, information reading without interference is experimentally achieved by choosing an appropriate filter and excitation wavelength, and multiple anti‐counterfeiting applications are demonstrated using a simple seal‐photocopy method. The results indicate that the targeted recombination strategy is very effective for achieving multifunctional applications of charge carrier trapping phosphors.

High-security-level multi-dimensional optical storage medium: nanostructured glass embedded with LiGa5O8: Mn2+ with photostimulated luminescence

“…The Quantex Corporation first evaluated its validity for ODS and extended the application to parallel Boolean logic operations and associative memory 23,24 . Recently, its prospect for ODS was demonstrated with the aid of bit-by-bit ultraviolet (UV)-/blue-laser encoding and global-scanned near-infrared (NIR)-laser decoding 21,[31][32][33] . Nevertheless, PSL materials are still not in consideration as an alternative to big data storage media due to their difficulties in achieving nanocrystallization-the light-matter interaction on the micrometre scale would result in a small writing/reading resolution to a great extent and thus limited storage capacity.…”

Facile synthesis of the desired red phosphor Li2Ca2Mg2Si2N6:Eu2+ for high CRI white LEDs and plant growth LED device

“…Thermal stability is of great importance affecting the luminescence performance, it is indispensable to evaluate the thermal quenching behavior and chromaticity stability of phosphor . The temperature‐dependent PL spectra of Li 2 Ca 2 Mg 2 Si 2 N 6 :1.0%Eu 2+ from room temperature (RT) to 473 K are depicted in Figure A‐B.…”

“…Thermal stability is of great importance affecting the luminescence performance, it is indispensable to evaluate the thermal quenching behavior and chromaticity stability of phosphor. 20,[26][27][28][29][30][31][32][33] The temperature-dependent PL spectra of Li 2 Ca 2 Mg 2 Si 2 N 6 :1.0%Eu 2+ from room temperature (RT) to 473 K are depicted in Figure 5A-B. With the temperature increasing, the emission intensity gradually decreases attributed to thermal quenching effect and the peak wavelength shows a slight blueshift.…”

Facile Synthesis of Mn4+-Activated Double Perovskite Germanate Phosphors with Near-Infrared Persistent Luminescence

“…TL measurements at temperatures in the range from 0 to 225 • C could be performed in a reliable way and the maximum 225 • C was fixed, and no higher temperature was applied in order to restrain the thermal quenching (TQ) effects. 6 ] are arranged alternately, sharing corner with one oxygen atom. This spatial arrangement of units in the La 2 MgGeO 6 double perovskite-type structure increases the distance between adjacent luminescent centers, improving the efficient NIR luminescence from the 2 E g → 4 A 2g emission process of Mn 4+ ions.…”

“…Persistent luminescence, also named long afterglow, is the optical phenomenon where light emission can persist for an appreciable time after the excitation source has been switched off. Materials with such self-sustained light emitting features are essential for a variety of applications in the fields of emergency lighting, anti-counterfeiting, night-vision signage, in vivo bio-imaging, and optical data storage [1][2][3][4][5][6]. The principles behind persistent luminescence of inorganic phosphors are related to traps and emitters.…”