Long persistent luminescence and photostimulated luminescence in Y3GaO6:Pr3+ phosphor

Long persistent luminescence (LPL) phosphors have a wide range of potential applications, including multi-color anticounterfeiting and long-term continuous detection of short-wavelength ultra-violet (UV) radiation. However, developing a stable carrier container that can provide ultra-long carrier storage for activators and visible multi-color LPL is a challenging task. In this work, we presented a series of Pr3+-doped Y3GaO6 (YGO) LPL phosphors that take full advantage of the synergistic relationship between the host lattice, emitters, and carrier traps. The host provides a suitable lattice site for rare-earth Pr3+ and offers a broad band gap of 5.69 eV to hold traps with depths ranging from 1.01 to 2.17 eV. We observed LPL that was visible to the naked eye for 6 h after excitation, and strong thermoluminescence (TL) spectra could be detected after the phosphor was placed in darkness for 20 days at room temperature. Additionally, we observed photostimulated luminescence under 980 nm and 808 nm laser irradiation with a power density of 5 W cm-2, indicating that low-energy excitation not only leads to LPL but also accelerates the elimination of previously stored carriers. After investigating the crystal structure and possible defects generated in the materials, we proposed a mechanism for LPL. Our findings demonstrate the potential of Pr3+-doped YGO LPL phosphors for a range of applications, such as multi-color anticounterfeiting and long-term continuous detection of short-wavelength UV radiation.