BaMgSiO4-based composites with photochromic and persistent luminescent behaviors for advanced anti-counterfeiting applications

Photochromic (PC) materials with persistent luminescent (PersL) behaviors show potential applications in advanced anti-counterfeiting and optical storage fields. However, it is difficult to simultaneously achieve PC and PersL properties in a single host, due to their different positions of defect energy levels between conduction band and valence band. In this work, a new strategy is proposed to obtain two features by constructing two-phase composites of photochromic BaMgSiO 4 :Eu 2+ and long afterglow Sr 2 MgSi 2 O 7 :Eu 2+ /Dy 3+ materials. The optimized composite sample not only exhibited the reversible white-purple color change by alternating 365 nm and 520 nm light irradiation, but also showed the blue afterglow luminescence for more than 20 min. The designed anti-counterfeiting component based on the composite sample provides a higher-level security anti-counterfeiting than conventional PC materials. These results may facilitate more innovative designs for future dynamic anti-counterfeiting and optical storage applications.