YAG:Ce纳米荧光粉发光的温度依赖特性

Temperature Dependence of Luminescence and Decay Time of YAG:Ce Nanophosphor

用沉淀法制备了YAG:Ce纳米荧光粉.用X射线粉末衍射仪(XRD)、扫描电子显微镜(SEM)对粉体煅烧过程的相变和形貌进行了表征.研究了80～400K范围内,YAG:Ce纳米荧光粉发光和衰减的温度依赖特性.结果表明,前躯体由纳米颗粒组成.900℃煅烧时,粉体由非晶态直接转变为YAG相.YAG:Ce的发光强度随温度的升高而减弱.YAG:Ce纳米荧光粉的衰减包含两个指数项,长时间项反映了体相Ce^(3+)的荧光衰减,随着温度的升高不断减小.短时间项反映了表面Ce^(3+)的荧光衰减,随着温度的升高呈下降趋势,由于受到表面效应的影响,中间出现小幅的阶跃.

Ce-doped Y3Al5O12 （YAG：Ce） nanophosphor was synthesized by the co-precipitation method X-ray powder diffraction （XRD）, Scanning electron microscope （SEM） were used to characterize the powders. The temperature dependences of luminescence and decay time of YAG：Ce nanophosphor were investigated in the temperature range of 80 -400K. The luminescence intensity decreases with the in- crease of temperature, which is caused by the increase of the non-radiative relaxation rate. The decay of YAG：Ce contains two exponential terms, the long component presents decay of Ce^3＋ in the body, the short component reflects decay of Ce^3＋ on the surface. The long component decreases with the increase of temperature, while the short component shows intricate behavior, which results from effect of surface.