M_(0.98)Al_2Si_2O_8:0.02Eu^(2+)(M=Ca,Sr,Ba)荧光粉发光性能的研究

Optical Properties of M_(0.98)Al_2Si_2O_8:0.02Eu^(2+)(M=Ca,Sr,Ba)

文中针对不同半径的阳离子对硅铝酸盐发光性能的影响展开研究,采用高温固相法在炭还原的条件下制备了M_(0.98)Al_2Si_2O_8:0.02Eu^(2+)(M=Ca,Sr,Ba))系列荧光粉,得到该系列样品都属于典型的Eu^(2+)的4f^65d^1-4f7(~8s_(7/2))的宽激发带和发射带,样品的发光中心分别位于438 nm(Ca)、422 nm(Sr)、371 nm(Ba),发蓝光。实验结果表明,发光强度随着离子半径的增加而减小,这是由于随着离子半径的增加晶场强度降低,而发光强度与晶场强度呈正相关。同时,发射光谱出现了蓝移的现象,这是由于晶场强度的不同,导致M_(0.98)Al_2Si_2O_8:0.02Eu^(2+)的5d下能级随着阳离子半径增加而降低。余辉性能同样随着阳离子半径的增加而减弱,这归结于不同碱金属离子与Eu^(2+)之间电势能差的不同。

In this paper,the effect of cations on the luminescent properties of aluminosilicates had been studied. M0.98Al2Si2O8：0.02Eu^2＋（M=Ca,Sr,Ba） was prepared by high temperature solid-state reaction under carbon reduction conditions. The obtained samples were all typical 4f^65d^1-4f^7（^8s7/2） transitions of Eu^2＋. Their luminescence centers were located at 438 nm（ Ca）,422 nm（ Sr） and 371 nm（ Ba）,respectively,and emitted blue light.The experimental results showed that the luminescence intensity decreased with the increase of the ion radius. The larger the ion radius,the lower the luminescence intensity due to the lower crystal field intensity,while the luminescence intensity was positively correlated with the crystal field strength. At the same time,a blue-shift phenomenon appeared due to the difference in the intensity of the crystal field,resulting in a decrease in the energy level at 5 d of M0.98Al2Si2O8：0.02Eu^2＋as the cation radius increased. Afterglow performance also decreased with increasing cation radius due to the difference in potential energy between different alkali ions and Eu^2＋.