微波场作用下La_2O_2S∶Eu荧光粉的快速合成及其发光特性  

Synthesis of La_2O_2S∶Eu Phosphor by Microwave Radiation Method and Its Luminescent Properties

作　　者：翟永清[1] 刘元红[1] 张少阳[1] 

机构地区：[1]河北大学化学与环境科学学院,河北保定071002

出　　处：《发光学报》2006年第6期905-909,共5页Chinese Journal of Luminescence

基　　金：河北省教育厅博士基金(B2004205);河北大学研究基金(Y2004024)资助项目

摘　　要：采用微波法快速合成了La2O2S：Eu红色荧光粉，用X射线粉末衍射（XRD）、扫描电镜（SEM）、荧光光谱等对合成产物进行了分析和表征。结果表明：材料的晶体结构为六方晶系，与纯La2O2S的结构相同。颗粒的形状不规则，分散性较好，尺寸在2μm左右。La2O2S：Eu的激发光谱主要是位于200—450nm范围内的宽带，此宽带激发来源于Eu^3＋的电荷转移态的吸收跃迁。在472nm左右出现一弱的尖锐的吸收峰，属于Eu^3＋的4f→4f跃迁吸收。发射光谱是由512，539，556，583，596，617，627nm的一系列窄带发射峰组成。这些发射峰归属于Eu^3＋从^5DJ（J=0，1，2）到^7FJ（J=0，1，2，3，4）的能级跃迁。随着Eu摩尔分数从2％增加到10％，主激发峰从348nm移动到365nm，移动了17nm；位于蓝绿区的发射峰逐渐减弱，627nm处的红光发射明显增强，当Eu的摩尔分数为8％时发光强度达到最大，继续增加Eu的浓度发光强度反而降低。Rare earth oxysulfide phosphor is a class of important luminescent materials. Because of their excellent properties, they have been applied extensively in fluorescent materials, X-ray phosphors, long afterglow phosphors, upconversion materials, and so on. So, rare earth oxysulfide phosphors are drawing more and more attention in recent years. Rare earth oxysulfide phosphors are usually produced by traditional solidstate reactions. In solid-state reactions, high reaction temperature, long heating time, and a special protective atmosphere are required to obtain a pure crystal phase. Therefore, producing agglomerated particles of irregular shape by solid-state reactions is unavoidable. Another disadvantage is the destruction of phosphor material during grounding and milling. The destruction results in the greatly decreasing of luminescence efficiency of the phosphors. In our present work, La202S： Eu, a red-emitting phosphor was rapidly synthesized by microwave radiation method for the first time. The synthesized phosphors were investigated respectively by XRD, SEM and fluorescence spectroscopy. The results show that La2O2S：Eu phosphors possess hexagonal crystal structure, which is similar to that of pure La2O2S. The particles of La2O2S：Eu phosphors are unregular in shape, dispersing well. The mean particle size is about 2 μm. The excitation spectrum of La2O2S：Eu is a wide band in the range of 200 - 450 nm. It results from the charge transfer states of Eu^3＋ ions （Eu^3＋ -O^2- , Eu^3 ＋ -S^2- ）. A narrow peak at 472 nm can been found in the excitation spectrum attributed to the f-f transition absorption of Eu^3＋ ions. The emission spectrum shows that La2O2S：Eu has a series of narrow emission peaks located at 512,539,556,583,596,617 and 627 nm. These emission peaks are attributed to Eu^3＋ ions transition from SDJ（J = 0, 1, 2） to ^7FJ （J = 0, 1, 2, 3, 4）. All the emission peaks are ascribed as follows, 617 nm and 627 nm （ ^5D0→^7F2 ）, 596 nm （ ^5D0→^7F1 ）, 583 nm （ ^5D0→^7

关 键 词：La2O2S:Eu 微波法 激发光谱 发射 光谱 

分 类 号：O482.31[理学—固体物理]