Fe³⁺-activated magnetoplumbite persistent luminescence phosphor by modulating the oxygen vacancy

Broadband near-infrared (NIR) spectroscopy has gained significant attention due to its versatile application in various fields. In the realm of NIR phosphors, Fe³⁺ ion is an excellent activator known for its nontoxic and harmless nature. In this study, we prepared an Fe³⁺-activated SrGa₁₂O₁₉ (SGO) NIR phosphor and analyzed its phase and luminescence properties. Upon excitation at 326 nm, the SGO:Fe³⁺ phosphor exhibited a broadband emission in the range 700-1000 nm, peaking at 816 nm. The optical band gap of SGO:Fe³⁺ was evaluated. To enhance the long-lasting phosphorescence, an oxygen vacancy-rich SGO:Fe³⁺ (V_O-SGO:Fe³⁺) sample was prepared for activation. Interestingly, the increase in the oxygen-vacancy concentration indeed contributed to the activation of persistent luminescence of Fe³⁺ ions. The V_O-SGO:Fe³⁺ sample has a long duration and high charge storage capacity, allowing it to perform efficiently in various applications. This work provides the foundation for further design of Cr³⁺-free PersL phosphors with efficient NIR PersL.