Long persistent luminescence property of green emitting Sr3Ga4O9: Tb3+ phosphor for anti-counterfeiting application

In this work, a long persistent luminescent (LPL) material Sr 3 Ga 4 O 9 :Tb 3+ is synthesized via a high-temperature solid-state reaction. The crystal structure, luminescence properties, decay curves and thermoluminescence (TL) curves of Sr 3 Ga 4 O 9 :Tb 3+ are studied in detail. When the ultraviolet (UV) light source was turned off, Sr 3 Ga 4 O 9 :Tb 3+ phosphor exhibit typical LPL behavior for approximately 7.5 h. The obtained results indicated that the green long persistent emitting was similar to the photoluminescence (PL), originated form the typical 5 D 4 → 7 F 5 transition of Tb 3+ ions. We propose the persistent luminescence mechanism of Tb 3+ doped Sr 3 Ga 4 O 9 . Electrons in the conduction band and holes in the valence band form stable excitons, and it can play an important role in energy transfer. Based on the specific characteristics of the phosphor, a dual-mode luminescence image is fabricated for application in anti-counterfeiting. • Tb 3+ was introduced in Sr 3 Ga 4 O 9 to generate feasible trap structure. • Sr 3 Ga 4 O 9 :Tb 3+ has excellent LPL performance at different temperatures. • The prepared flexible anti-counterfeiting device has better security and confidentiality.