Photoluminescence, thermoluminescence and radioluminescence properties of Sm3+/Cr 3+-doped Zn3Ga2Ge2O10 after sunlight and X-ray activation

Near-infrared (NIR) persistent phosphors have been explored extensively owing to their strong luminescence and long afterglow after being activated by sunlight or ambient light. However, developing new high-performance NIR persistent phosphors and expanding their applications in the field of X-ray luminescence remain significant challenges. Here, a series of Zn3Ga2Ge2O10 NIR persistent phosphors were prepared via a high-temperature solid-phase method. Among them, Zn3Ga2Ge2O10: Cr3+, Sm3+ phosphors can be excited by ultraviolet light, visible light or sunlight, or X-rays, and all show strong luminescence and long afterglow. Moreover, at the operating temperature of the LED, the luminous intensity of the sample under X-ray excitation is 1.3 times greater than that at room temperature, indicating good radioluminescence performance and high-temperature thermal stability. The NIR decay time excited by visible light exceeds that of Zn3Ga2Ge2O10: Cr and Zn3Ga2- Ge2O10: Cr, Pr. The descriptive mechanism of the afterglow phenomenon is introduced, and the depth and concentration of the afterglow trap are calculated according to the thermoluminescence curve. The linear range of the dose response is very wide, and the characteristic dose of the composite action model is 1583 Gy. This study shows that the codoping of Cr3+ and Sm3+ can provide an optimal strategy for the application of new NIR materials in lighting, night vision monitoring, solar energy utilization, in vivo bioimaging, and plant light sources and provides a good example for future research in X-ray detection and imaging.