Growth regulation of an easily crystallized organic long-persistent luminescence system with in situ anti-counterfeiting applications

Abstract

Organic long-persistent luminescence (OLPL) materials present significant promise in anti-counterfeiting and information encryption due to their straightforward preparation process and adjustable luminescence properties. In this study, we present a novel approach to the growth regulation of OLPL systems, focusing on an easily crystallizable doping system for in situ anti-counterfeiting applications. Utilizing p-TPD as the guest molecule and various host molecules, we synthesized doped crystals with uniform particle size and afterglow durations ranging from 2.0 s to 4.5 s. Furthermore, leveraging the unique host–guest pairing relationship and facile crystallization characteristics, we developed a “paper-ink” encryption strategy with in situ anti-counterfeiting capabilities. This innovative approach allows encrypted paper and paired ink to fully display encrypted information, while ordinary paper treated with the ink remains blank unless further processed with an information display reagent. Notably, the encrypted paper maintains its encryption effectiveness even when exposed to water. These advancements underscore the potential of organic-doped long afterglow materials in enhancing information security for secure communication and data protection.