Strontium substitution enhancing a novel Sm3+-doped barium gallate phosphor with bright and red long persistent luminescence

The blue/green long persistent phosphors (LPPs) have been commercially available, however, LPPs with red emission are relatively rare and there is still a strong desire for exploring excellent red LPPs. In this work, we developed a novel red LPP BaGa2O4: Sm3+ by solid-state reaction. Photoluminescence and long persistent luminescence (PersL) properties of this phosphor were investigated systematically. By studying the structural information of the BaGa2O4, a substitution strategy was implemented to enhance the PersL performance. The PersL properties are effectively improved due to the increasing concentration of traps caused by the substitution of Sr. With the help of the initial rise method, the existence of continuous and wide trap depth distribution in Ba0.94Sr0.06Ga2O4: 0.01Sm(3+) were revealed. In addition, the photostimulated luminescence was also investigated. Ultimately, a possible mechanism is discussed.