JIA Hongshuai, ZHU Qi, SUN Xudong
(School of Materials Science and Engineering, Northeastern University, Shenyang 110819, Liaoning, China)
Abstract: Near-infrared (NIR) persistent luminescence phosphors, ZnGa2O4:0.005Cr3+,xLi+, were synthesized by using ahigh-temperature solid state reaction method. The phosphors were characterized by using XRD, SEM, TEM, Uv-Vis, PL/PLE,PLE/PL, in order to examine the influence of Li+ on their microstructure and properties. The phosphors output NIR afterlow(2E→4A2 transition of Cr3+) upon UV or visble excitation. Incorporation of Li+enhanced the efficiency of visible light excitation, thus lading to an enhancement in NIR emission. As the x value was increased from 0 to 0.07, the excitation intensities of 407 nm and 555 nm were increased by 114% and 120%, respectively. The type and concentration of traps of ZnGa2O4:Cr3+ were significantly dependent on the incorporation of Li+. The sample with x=0.07 had a high concentration of deep traps and thus exhibited high-intensity afterglow through recycle heating, indicating potential application in optical information storage.
Key words: near-infrared persistent luminescence; persistent luminescence; trap