Upconverted persistent luminescent Zn3Ga2SnO8: Cr3+, Yb3+, Er3+ phosphor for composite anti-counterfeiting ink

Herein, a novel colorless anti-counterfeiting luminous ink composite material, to the best of our knowledge, was prepared by incorporating upconverted persistent luminescent Zn3Ga2SnO8:1%Cr3+, 5%Yb3+, 0.5%Er3+ (ZGSO: Cr,Yb,Er) phosphors into a resin solution, followed by stirring. Owing to its small particle size and uniform distribution, ZGSO: Cr, Yb, Er exhibits long-lasting, persistent near-infrared emission at 696 nm following the stoppage of excitation by a 274 nm ultraviolet light and a 980 nm excitation. ZGSO: Cr, Yb, Er composites were prepared and exhibited characteristic peaks corresponding to upconversion and an afterglow curve following excitation at 980 nm. With various special luminescent modes, sharp emission peaks, and emission intensity varying over time, the emission light of composite ink is easy to detect and not easily confused. Furthermore, the prepared composite ink can be calligraphic, visualized, and observable, and has good light-emitting performance following UV excitation. Our work provides a meaningful way to fabricate multifunctional anti-counterfeiting luminous ink composites with an intense persistent luminescence for use in anti-counterfeiting signs, inspection imaging, and other complex industrial applications.