Highly stable double-emission long afterglow phosphor for dynamic anti-counterfeiting

A highly stable single-excitation double-emission long afterglow phosphor is reported for use in dynamic anti-counterfeiting. The red phosphor ZnCaGa 2 O 4 :Cr 3+ was introduced into the pores of mesoporous silica nanoparticles (MSNs) by in situ polymerization, and the green phosphor SrAl 2 O 4 :Eu 2+ ,Dy 3+ , when embedded in silicon dioxide, provided a long-lasting waterproof afterglow. The anti-counterfeiting material emits red light under UV excitation at 254 nm and, on stopping the excitation, produces a long-lasting green afterglow. Traditional anti-counterfeiting methods often require the use of a variety of different excitation light sources to achieve different luminous effects, while this innovative material requires only one excitation light source to achieve red light and green afterglow, and greatly simplifies the preparation process of anti-counterfeiting materials. In addition, this material is highly stable and can maintain its luminescent properties for a long time under various environmental conditions and is not prone to fading or degradation. Single-excitation dual-emission long afterglow anti-counterfeiting materials can effectively prevent products from being counterfeited, and this study provides new ideas and methods for technological innovation in the field of anti-counterfeiting.