Luminescent Properties of Li+doped Sr_2MgSi_2O_7∶Eu~(2+),Dy~(3+) Phosphors
XIAO Ling;ZHOU Jian;LIU Gui-zhen;State Key Laboratory of Advanced Technology for Materials Synthesis and Procesing,Wuhan University of Technology;
Sr_2MgSi_2O_7∶Eu~(2+),Dy~(3+)and Sr_2MgSi_2O_7∶Eu~(2+),Dy~(3+),Li+phosphors were prepared by conventional solid state reaction method,and the influence of Li+doping on the luminescent properties of Sr_2MgSi_2O_7∶Eu~(2+),Dy~(3+) phosphors was studied. The samples were characterized by X-ray diffraction( XRD),scanning electron microscope( SEM),photoluminescence( PL),decay curves,and thermoluminescence( TL). The results indicate that the incorporation of Li+ions has no influence on the position of the emission peak which is determined by 4f~7→4f~65d~1of Eu~(2+),while it has relationships with the intensity of the emission and the afterglow. The highest phosphorescent intensity was observed with 2. 5% of Li+,and compared with the undoped sample,the phosphorescent intensity and the decay constant were increased by 1. 5 and 1. 6 times,respectively. By the characteristic of TL measurement,the number and the depth of trap level were analyzed. The doping of Li+can increase the number of oxygen vacancies and increase the trap depth,so as to improve the afterglow properties of phosphor.