UV-Vis-NIR broadband-photostimulated luminescence of LiTaO3:Bi3+ long-persistent phosphor and the optical storage properties

Trap depth is an important factor in the design of long-persistent (LPL) or photostimulated luminescence (PSL) materials, lithium tantalate is a promising matrix with abundant defect traps owing to the volatile lithium. The new long-persistent luminescence material LiTaO3:Bi3+ exhibits intense indigo blue photoluminescence (PL) and long-persistent luminescence with the maximum peak located at 430 nm, which is ascribed to the P-3(1)-> S-1(0) , transition of Bi3+, while the decay rate of afterglow increases when the concentration of Bi(3+)dopant improves. Under near-infrared (NIR) stimulation, the synthetic phosphor shows bright indigo blue photostimulated luminescence, but the UV-Vis stimulation light can quench afterglow rapidly due to its efficient photostimulation effect related to the distribution and depth of defect traps in matrix crystal. By means of photostimulated luminescence spectra, thermoluminescence (FL) curves and X-ray photoelectron spectroscopy (XPS), the impact of antisite-tantalum defect traps on luminescence property is characterized. The findings give insight into the mechanism of photostimulated luminescence and expand the application field of long-persistent luminescence materials in optical information storage.