Li~+掺杂Sr_2MgSi_2O_7∶Eu~(2+),Dy~(3+)长余辉材料的发光性能

采用高温固相法制备Li+掺杂Sr2Mg Si2O7∶Eu2+,Dy3+长余辉材料,对样品进行X射线衍射、扫描电镜、激发光谱、发射光谱、余辉衰减曲线和热释光曲线表征,研究了Li+掺杂对Sr2Mg Si2O7∶Eu2+,Dy3+发光性能的影响。实验结果表明:Li+掺杂对样品激发光谱和发射光谱的峰形、峰位基本没有影响,但是能改善样品的余辉性能。与未掺杂Li+的样品比较,Li+掺杂摩尔分数为2.5%样品的初始发光强度提高了1.5倍,余辉衰减常数提高了1.6倍。通过热释光曲线表征分析陷阱数量并计算了陷阱深度,分析表明,掺杂Li+能增加基质中氧空位的数量,适量增加陷阱深度,从而提高材料的发光性能。

Luminescent Properties of Li+ doped Sr2MgSi2O7∶Eu2+,Dy3+ Phosphors

Sr2MgSi2O7∶Eu2+,Dy3+and Sr2MgSi2O7∶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 Sr2MgSi2O7∶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1 of 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.