Perovskite-Based Nanostructures for Fluorescence Afterglow Anticounterfeiting

Abstract

Advanced fluorescence anti-counterfeiting technology has attracted the attention of researchers and encourages people to develop more materials with more colors and functions. Here, in order to achieve a full-band afterglow in the visible light region, we designed a composite CsPbI3-CsPbBr3/Sr2MgSi2O7:Eu2+,Dy3+@SiO2, which is composed of nanoscale all-inorganic cesium lead perovskite quantum dots (PQDs) and long-afterglow luminescent materials Sr2MgSi2O7:Eu2+,Dy3+ (SMS). SMS is used to store light energy, and PQDs are used to control afterglow emission colors; through their energy transfer, the afterglow colors can be adjusted in the visible region. SiO2 is used as the coating material to improve the temporary stability of the nanocomposite. The composite mixed with oleic acid (OA) can be used as a dye, which exhibits different emitting colors and afterglow colors under different excitation environments. This research provided an idea for using long-afterglow luminescent materials and PQDs in the field of fluorescence anti-counterfeiting by double anti-counterfeiting of fluorescence and afterglow.

Photorewriting, Time-Resolved Encryption, and Unclonable Anticounterfeiting with Artificial Intelligence Authentication via a Reversible Photoswitchable System

“…In the digital age, information can be disseminated through a wide variety of means, including printed material, radio, television, and the Internet. − However, easy access to information through multiple channels has also led to the common occurrence of confidential and secure information, such as passports, bank checks, and ID cards, being forged or leaked, posing significant property and security risks to individuals, companies, and even governments. − From the recognition of the necessity for diverse anticounterfeiting labels, it is noted that the majority of these labels are static and susceptible to replication. With inspiration from the color-changing mechanisms observed in nature, the development of anticounterfeiting labels with dynamic color-changing capabilities proves effective in mitigating issues related to replication. − Consequently, researchers have created a range of anticounterfeiting materials with various stimulus-responsive properties, all of which are inspired by these distinctive qualities. − Among them, optical materials are advantageous because to their simple processing, high yield, and exact design. ,− However, because most optical materials rely on static characteristics or signals and particular security features are easily replicated, they offer minimal security. − Considering this, organic multistimulus-responsive luminescence materials would be promising candidates. − As a result of the fact that they exhibit color and fluorescence change behavior in response to stimuli as well as a controllable structure and function, responsive materials have important applications in the field of anticounterfeiting and information encryption. In recent years, a variety of stimuli-sensitive materials have been developed for mixed combinations of light, − temperature, pH, electricity, ions, mechanical forces, and other stimuli …”

Coating Red Phosphor on Green Luminescent Material for Multi-Mode Luminescence and Advanced Anti-Counterfeit Applications

“…Long afterglow luminescent materials are a type of light-storage luminescent material with a unique characteristic. They can slowly release energy in the form of light after the light source is turned off [13]. This slow release can generally last for hours or even days.…”