白光LED用Ca_8Mg(SiO_4)_4Cl_2:Eu^(2+),Dy^(3+)发光粉的发光性能  

Luminescent Properties of Ca_8Mg(SiO_4)_4Cl_2:Eu^(2+),Dy^(2+) Phosphor for White LED

作　　者：沈超[1] 邵起越[1] 韩学林[1] 董岩[1] 蒋建清[1] 

机构地区：[1]东南大学材料科学与工程学院江苏省先进金属材料高技术重点实验室,江苏南京211189

出　　处：《发光学报》2010年第1期44-48,共5页Chinese Journal of Luminescence

基　　金：教育部重大项目培育基金(707029);江苏省自然科学基金(BK2008317)资助项目

摘　　要：采用高温固相法合成了白光LED用Ca8Mg(SiO4)4Cl2:Eu和Ca8Mg(SiO4)4Cl2:Eu,Dy绿色发光粉。研究发现:共掺Dy可以明显地提高Ca8Mg(SiO4)4Cl2:Eu发光粉的发光性能,表明Dy3+和Eu2+之间存在着能量传递过程。当Dy3+的最佳掺杂摩尔分数为0.02时,发光粉505nm处绿光发射的强度约提高12%。通过对Dy3+和Eu2+光谱特性的分析,Dy3+和Eu2+之间的能量传递机制可归因于无辐射交叉弛豫。Calcium magnesium chlorosilicate [Ca8Mg（SiO4）4C12] doped with Eu2＋ can be used as a kind of green phosphor for white-light LED because of its effective excitation under NUV light source and bright green emission. However, according to the current research, the relative brightness of this green phosphor had to be improved. In this paper, calcium magnesium chlorosilicate [ Ca8Mg（SiO4 ）4O2 ] green phosphors, doped with Eu2＋ or co-doped with Eu2＋ and Dy3＋ , were synthesized by high-temperature solid-state reaction in reducing atmosphere. The luminescent properties of these phosphors, as well as the interaction mechanism between Dy3＋ and Eu2＋ , were investigated. The significant enhancement of CasMg（ SiO4 ）4C12： Eu2＋ green emission was obtained by co-doping with Dy3＋ , and the 505 nm emission intensity of Eu2＋ is increased by 12% with an optimum Dy3＋ content of 0.02. Funthermore, the concentration quenching process was also discovered, and the luminescent intensity of CasMg （SiO4）4C12： Eu2＋, Dy2＋ phosphor decreases with further increasing the concentration of Dy3＋. In this paper, It is suggested to be an energy transfer process between Dy3＋ and Eu2＋on the basis of spectral characteristics of Dy3＋ and Eu2＋. On account of the relatively low intensity of Dy3＋ 4f4f emission, the energy transfer could be radiation reabsorption process. On the other hand, the energy transfer mechanism might be ascribed to resonant transfer process, for the radiative lifetime of the 4f-4f forbid- den electric-dipole transition of Dy3＋ is much longer than that of the 5d-4f transitions of Eu2＋ . Thus, the most likely energy transfer mechanism between Dy3＋ and Eu2＋ can be attributed to nonradiative cross relaxation process.

关 键 词：白光LED Ca8Mg(SiO4)4Cl2:Eu2+ Dy3+ 发光性能 能量传递 

分 类 号：O482.31[理学—固体物理]