Zero‐Dimensional Zn‐Based Halides with Ultra‐Long Room‐Temperature Phosphorescence for Time‐Resolved Anti‐Counterfeiting

Abstract

Though fluorescence‐tag‐based anti‐counterfeiting technology has distinguished itself with cost‐effective features and huge information loading capacity, the clonable decryption process of spatial‐resolved anti‐counterfeiting cannot meet the requirements for high‐security‐level anti‐counterfeiting. Herein, we demonstrate a spatial‐time‐dual‐resolved anti‐counterfeiting system based on new organic–inorganic hybrid halides BAPPZn2(ClyBr1−y)8 (BAPP=1,4‐bis(3‐ammoniopropyl)piperazinium, y=0–1) with ultra‐long room‐temperature phosphorescence (RTP). Remarkably, the afterglow lifetime can be facilely tuned by regulating the halide‐induced heavy‐atom effect and can be identified by the naked eyes or with the help of a simple machine vision system. Therefore, the short‐lived unicolor fluorescence and lasting‐time‐tunable RTP provide the prerequisites for unicolor‐time‐resolved anti‐counterfeiting, which lowers the decryption‐device requirements and further provides the design strategy of advanced portable anti‐counterfeiting technology.

Reversible human-temperature-responsive luminescence switching in a Mn(ii)-based metal halide

“…Stimuli-responsive luminescent materials, with a specific response to external stimuli such as light, 1 pressure, 2 solvent molecules, 3 and heat, 4,5 have attracted extensive research interest and have shown wide application potentials in information storage, [6][7][8] chemical sensing, [9][10][11] and anti-counterfeiting. [12][13][14][15] In particular, thermosensitive materials are praised for their simple heating device requirement, highlighting their applications in thermal imaging, and thermometers. However, the thermal-response temperatures of previously reported thermosensitive materials are either below the refrigeration temperature or much higher than room temperature (RT).…”

Metal-Halide Coordination Polymers with Excitation Wavelength- and Time-Dependent Ultralong Room-Temperature Phosphorescence

“…As a comparison, the delayed spectrum for the pristine bpp in Figure S5 shows a weak emission at 490 nm. It has been reported that halogen atoms can lead to a bathochromic shift, reduction of lifetime, and enhancement of quantum efficiency of phosphorescence. ,, Therefore, the emission at around 490 nm can be assigned to the emission of bpp, while the emission >490 nm is related to the interaction of bpp with halogen atoms. Recalling some previous work, compounds containing X...π interactions have shown excitation wavelength-dependent photoemission.…”

“…As another well-known class of heavy atoms, halogens with high nuclear charge can enhance the probability of spin-orbital coupling (SOC) and increase the probability of S n → T n system crossing. The enhancement of distribution density of the T 1 state is beneficial to the generation of RTP with high quantum yield. − …”

Recent advances in room temperature phosphorescence materials: design strategies, internal mechanisms and intelligent optical applications

“…5f). 59 Liu et al designed and fabricated a 0-D OIHMH material, (Ph 4 P) 2 Cd 2 X 6 (X = Cl and Br) with green RTPs. (Ph 4 P) 2 Cd 2 Br 6 exhibited excellent thermal-quenching-resistant properties of RTP efficiency (62.79%) and lifetime (37.85 ms) in the range of 100 to 320 K, which is rare for OIHMHs.…”

“…(e) The phosphorescence mapping of BAPPZn 2 Cl 8 . (f) The time-resolved encryption and decryption process 59. Copyright 2018, Wiley-VCH Verlag GmbH & Co. KGaA.…”