Design, Synthesis, and Characterization of a Novel Blue-Green Long Afterglow BaYAl(3)O(7):Eu(2)(+), Nd(3)(+) Phosphor and Its Anti-Counterfeiting Application

Herein, a series of novel long afterglow nanophosphors BaYAl(3)O(7):Eu(2)(+), Nd(3)(+) was synthesized by the combustion method. The investigation encompassed the characterization of X-ray diffraction, morphology, chemical valence, elemental composition, and photoluminescence behavior of BaYAl(3)O(7):Eu(2)+ and BaYAl(3)O(7):Eu(2)(+), Nd(3)(+) nanoparticles. Under 365 nm excitation, BaYAl(3)O(7):Eu(2)(+) and BaYAl(3)O(7):Eu(2)(+), Nd(3)(+) show emission bands centered at 497 nm and 492 nm, which are attributed to the 4f(6)5d→4f(7) transition of Eu(2)(+) ions. The optimal samples of BaYAl(3)O(7):0.03Eu(2)(+) and BaYAl(3)O(7):0.03Eu(2)(+), 0.02Nd(3)(+) have average fluorescence lifetimes of 850 ns and 1149 ns, respectively. The co-doping of Nd(3)+ 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.