白光LED用蓝绿色荧光粉Sr_(1-x)Ba_xAl_2O_4:Eu^(2+)的发光性质  

Luminescence Properties of Blue-green Phosphors Sr_(1-x)Ba_xAl_2O_4:Eu^(2+) for White LED

作　　者：杨志平[1] 周东站[1] 马淑媛[1] 于红伟[2] 刘玉峰[1] 李旭[1] 

机构地区：[1]河北大学物理科学与技术学院,河北保定071002 [2]河北大学电子信息工程学院,河北保定071002

出　　处：《发光学报》2011年第8期755-760,共6页Chinese Journal of Luminescence

基　　金：河北省自然科学基金(F2009000217)资助项目

摘　　要：采用高温固相法在还原气氛中合成Sr1-xBaxAl2O4∶Eu2+荧光材料。XRD显示,当钡掺杂量x<0.4时,对应样品主要为单斜SrAl2O4晶体结构;当x≥0.4时,对应样品主要为简单六方BaAl2O4晶体结构。在360nm激发下,样品的发射光谱随x的增加由单一的绿光发射(λmax=516 nm)逐渐转变为蓝绿光双发射(λmax1=441 nm,λmax2=486 nm)。在Eu2+摩尔分数为0.29%时,双发射峰强度最强;继续增加Eu2+浓度,将出现浓度猝灭。研究表明,Sr1-xBaxAl2O4∶Eu2+的浓度猝灭机理为电偶极-电偶极相互作用。Sr1-xBaxAl2O4∶Eu2＋ phosphors were synthesized in a reducing atmosphere by high temperature solid state method at 1 350 ℃.The patterns of XRD indicated that the crystal structure of the phosphors are the monoclinic phase of SrAl2O4 when x0.4 and the simple hexagonal phase of BaAl2O4 when x≥0.4 because of crystal lattice expands with Ba2＋ ion substitution for Sr2＋ ion.Photoluminescence experiments were carried out to study the luminescence properties of the phosphors excited under 360 nm.The results showed that emission spectra gradually changed from single green emission（λmax=516 nm） to blue-green dual-emission（λmax1= 441 nm,λmax2=486 nm） with the increase of x. When x was 0.5,there was a better property in Sr0.5Ba0.5Al2O4∶Eu2＋.From the relationship between the concentration of Eu2＋ ion and the intensities of emissions in Sr0.5Ba0.5Al2O4∶y%Eu2＋,we get that the maximum dual-emission intensity when y=0.29%.There exist a concentration quenching effect in Sr0.5Ba0.5Al2O4∶Eu2＋, and the study points out that the mechanism of concentration quenching effect is electric dipole-dipole interaction.

关 键 词：白光LED 荧光材料 SRAL2O4 浓度猝灭 

分 类 号：O482.31[理学—固体物理]