Design, Synthesis, and Characterization of a Novel Blue-Green Long Afterglow BaYAlO:Eu, Nd Phosphor and Its Anti-Counterfeiting Application.

Herein, a series of novel long afterglow nanophosphors BaYAlO:Eu, Nd was synthesized by the combustion method. The investigation encompassed the characterization of X-ray diffraction, morphology, chemical valence, elemental composition, and photoluminescence behavior of BaYAlO:Eu+ and BaYAlO:Eu, Nd nanoparticles. Under 365 nm excitation, BaYAlO:Eu and BaYAlO:Eu, Nd show emission bands centered at 497 nm and 492 nm, which are attributed to the 4f5d→4f transition of Eu ions. The optimal samples of BaYAlO:0.03Eu and BaYAlO:0.03Eu, 0.02Nd have average fluorescence lifetimes of 850 ns and 1149 ns, respectively. The co-doping of Nd+ ions as the trap centers produced long afterglow luminescence properties, and the afterglow time could reach up to 8 min. Furthermore, the fluorescent powder can be mixed with polyacrylic acid to prepare anti-counterfeiting inks; a clover pattern and snowflake pattern have been successfully printed using screen printing technology, proving its potential application in the field of anti-counterfeiting.