Commendable Pr3+-activated Ba2Ga2GeO7 phosphor with high-brightness white long-persistent luminescence

Long-persistent phosphors can be used in diverse fields, such as emergency instruction, information storage and in vivo bioimaging. Currently, progress in research and development of white longpersistent phosphors is slow, although there is growing demand for applications in certain conditions. In this work, a novel white long-persistent phosphor Ba2Ga2GeO7: Pr3+ was synthesized and systematically investigated through its structural information, photoluminescence and phosphorescence properties. Under ultraviolet light excitation, this phosphor gives white emission containing greenish-blue and red components stemming from 3P0 and 1D2 multiplet electron transitions in the 4f level of Pr3+. The luminescent color of the phosphors is relatively stable at different temperatures and Pr3+ concentrations. Bright white afterglow can be observed by the naked eye in the dark for 3 hours after removal of the excitation source. Finally, a feasible afterglow mechanism of Ba2Ga2GeO7: Pr3+ with a trap-detrap scenario was proposed to clarify the generation of the white afterglow.