A dynamic irradiation-responsive material for advanced anti-counterfeiting in dark and bright fields

Abstract

Anti-counterfeiting is an important issue in this time of information. However, the most significant shortcoming of the present luminescence anti-counterfeiting is that the luminescent color and body color of the anti-counterfeiting label will not change under irradiation, so it is easy to be counterfeited by substitutions. In this work, an interesting dynamic irradiation-responsive material CaZnGe₂O₆ : Pb²⁺ is developed. It is demonstrated that the CaZnGe₂O₆ : Pb²⁺ material shows dynamic photoluminescence in the dark field and dynamic photochromism in the bright field under irradiation. Consequently, the photoluminescent color and body color of the CaZnGe₂O₆ : Pb²⁺ powder could change dynamically under irradiation. Based on the unique irradiation-responsive features, a CaZnGe₂O₆ : Pb²⁺/PDMS film label is fabricated for anti-counterfeiting applications in both dark and bright fields, and it shows excellent application potential in advanced anti-counterfeiting.