Triple-Modal Anti-Counterfeiting Based on CsPbBr₃ Perovskite Quantum Dot/CaAl₂O₄:Eu²⁺, Nd³⁺ Composites with Dual Fluorescence Properties

Abstract

Advanced fluorescent anticounterfeiting technology has received widespread attention due to the lack of sufficient security of traditional anti-counterfeiting. Hence, there is a great challenge to continuously develop multi-level anti-counterfeiting technology with higher security. Here, we develop a desired fluorescent anticounterfeiting technology based on CsPbBr 3 perovskite quantum dots (PQDs) and CaAl 2 O 4 :Eu 2+ , Nd 3+ composites with persistent luminescence properties. CsPbBr 3 PQDs can be formed on the surface of the CaAl 2 O 4 host and exhibit an average diameter of around 3.5 nm. The photoluminescence (PL) intensity of CsPbBr 3 PQDs/CaAl 2 O 4 composites is greatly enhanced to 125 times compared to that of pure CsPbBr 3 PQDs, and the desired narrow FWHM of 19 nm is achieved under near-ultraviolet irradiation. Furthermore, highly stable CsPbBr 3 PQDs/CaAl 2 O 4 :Eu 2+ , Nd 3+ composites with triple-modal (UV, IR, and thermal) fluorescent anti-counterfeiting characteristics were developed and used in fabricating anti-counterfeiting labels through screen-printing technology. The results open up a pathway to enhance the photoluminescence properties and stability of perovskite quantum dots for the advanced fluorescent anticounterfeiting application.

Expanding the Emission of CsPbBr3 Nanocrystals in the Blue Region

“…On the other hand, the Eu 2+ -doped CsPbBr 3 NCs show two emission peaks with the same excitation wavelength used for the undoped CsPbBr 3 . These emission peaks appear in the green region at 498 nm and and in the blue region at 442 nm . The fwhm values are 20 and 13 nm for the green and blue emission, respectively.…”

Insight into the Water-Triggered Conversion of Cs4PbBr6/Mesoporous Silica-Based Nanocomposites: In Situ Formation, Water Responsiveness, and Multistage Anticounterfeiting

“…Wang et al designed a multilevel anticounterfeiting system by using CsPbBr 3 PQDs/ CaAl 2 O 4 Eu 2+ ,Nd 3+ composites via a screen-printing strategy and designed a unique dual-color (blue/green) emission. 21 waterproof directly written ink. 22 Among the diversified perovskite materials, zero-dimensional Cs 4 PbX 6 NCs exhibit extensive demand.…”

“…Their simple preparation process, − low cost, controllable quantum morphology, − extremely high fluorescence quantum efficiency, adjustable fluorescence wavelength (400–700 nm), and a narrow half-peak width (12–42 nm) − make the perovskite an excellent candidate for anticounterfeiting fluorescent inks. Wang et al designed a multilevel anticounterfeiting system by using CsPbBr 3 PQDs/CaAl 2 O 4 Eu 2+ ,Nd 3+ composites via a screen-printing strategy and designed a unique dual-color (blue/green) emission . Shi et al proposed a one-pot method for synthesizing CsPbBr 3 /CsPb 2 Br 5 material and transformed CsPbBr 3 NCs to CsPbBr 3/ CsPb 2 Br 5 by adjusting the reaction time, yielding a waterproof directly written ink …”