Multi-leveled Static-dynamic Anticounterfeiting Based on the Stimuli-responsive Luminescence in A Niobate Structure.

Anticounterfeiting is a highly required technique to protect the product and the consumer rights in modern society. The conventional luminescent anticounterfeiting is based on down-conversion luminescence excited by an ultraviolet light, which is easy to be faked. In this work, we realized six luminescent modes in a niobate-based structure, (LiNbO3: RE3+, RE3+ = Pr3+, Tm3+, Er3+, Yb3+), in which the photo-stimulated luminescence of LiNbO3: Pr3+, persistent luminescence of Li0.99NbO3: Pr3+, and up-conversion luminescence color evolution of LiNbO3: Er3+ were first presented. Based on the above luminescent modes of LiNbO3: RE3+, multi-leveled anticounterfeiting devices were developed. By employing the mechanoluminescence and persistent luminescence, we achieved a dual-mode anticounterfeiting which could display the luminescent patterns without any direct irradiation. In addition, another dual-mode anticounterfeiting based on photo-stimulated luminescence and up-conversion luminescence excited by a near infrared light was realized, which could display the anticounterfeiting patterns in both static and dynamic states. To obtain an even higher anticounterfeiting level, the down-conversion luminescence, thermoluminescence, photo-stimulated luminescence and up-conversion luminescence were simultaneously applied in a food trademark. This four-mode anticounterfeiting trademark could not only show a static-dynamic luminescence that is hard to be faked, but also allow consumers to distinguish the food freshness. The presented multi-leveled anticounterfeiting strategies could be employed to resolve the counterfeit issues in various fields.