Unclonable Perovskite Fluorescent Dots with Fingerprint Pattern for Multilevel Anticounterfeiting

Abstract

Anticounterfeiting techniques based on physical unclonable functions exhibit great potential in security protection of extensive commodities from daily necessities to high-end products. Herein, we propose a facile strategy to fabricate an unclonable super micro fingerprint (SMFP) array by introducing in situ grown perovskite crystals for multilevel anticounterfeiting labels. The unclonable features are formed on the basis of the differential transportation of a microscale perovskite precursor droplet during the inkjet printing process, coupled with random crystallization and Ostwald ripening of perovskite crystals originating from their ion crystal property. Furthermore, the unclonable patterns can be readily tailored by tuning in situ crystallization conditions of the perovskite. Three-dimensional height information on the perovskite patterns are introduced into a security label and further transformed into structural color, significantly enhancing the capacity of anticounterfeiting labels. The SMFPs are characterized with tunable multilevel anticounterfeiting properties, including macroscale patterns, microscale unclonable pattern, fluorescent two-dimensional pattens, and colorful three-dimensional information.

Unclonable Micro‐Texture with Clonable Micro‐Shape towards Rapid, Convenient, and Low‐Cost Fluorescent Anti‐Counterfeiting Labels

“…[24] Liu et al proposed a facile strategy to fabricate an unclonable super micro fingerprint array by introducing in situ grown perovskite crystals for multilevel anti-counterfeiting labels. [10] Yu et al demonstrated the potential applications of hydrochromic CsPbBr 3 NCs in anti-counterfeiting by using CsPbBr 3 NCs@ mesoporous silica nanospheres as the starting material. [25] In this paper, we introduce an unclonable anti-counterfeiting technique with high-throughput and low-cost preparation and convenient, rapid, and repeatable verification.…”

“…[5,6] Anti-counterfeiting labels with physical unclonable functions (PUF) are a feasible solution to the above shortcomings. Since the introduction of the PUF in 2002, [7] many anticounterfeiting labels with different PUF characteristics have been developed, such as unique bionic fingerprint pattern with random surface topography; [8][9][10] randomly distributed nanoparticle pattern, including flower-like patterns with random pinning points, [11] nanowires coated with fluorescent dyes in random positions, [12] etc. In addition, researchers have prepared many types of PUF anticounterfeiting labels with optical response.…”

In Situ Inkjet Printing Patterned Lead Halide Perovskite Quantum Dot Color Conversion Films by Using Cheap and Eco‐Friendly Aqueous Inks

“…Another is “non‐fluorescent” ink, which is produced by dissolving raw materials of PQDs in a solvent to form transparent precursor solutions. [ 27,28 ] After printing the ink on the substrate, in situ crystallization of patterned PQD CCFs occurs as the solvent evaporates. For instance, Li et al.…”

Luminescence anti‐counterfeiting: From elementary to advanced

“…[ 6–10 ] According to the previous reports, the global economic losses caused by counterfeiting may reach to 1.82 trillion USD in 2020. [ 11 ] Therefore, developing powerful anti‐counterfeiting technologies is highly demanded.…”