【作者】 陈震旻；

【导师】 何大伟；

【作者基本信息】 北京交通大学 ， 光学， 2010， 硕士

【摘要】 硅酸盐基质具有良好的化学稳定性和热稳定性,长期以来人们都重视对硅酸盐基质荧光粉的研究和开发。单一基质白光荧光粉因具有流明效率高、色彩还原性好等特点,所以对其研究的意义重大。本文主要采用高温固相法,合成了M2SiO4:Dy3+,Eu3+(M=Mg, Ca)系列LED用荧光粉,并对样品相应结构特性和近紫外光激发下的发光特性进行了研究。系列样品M2SiO4:Dy3+,Eu3+(M=Mg, Ca)的X射线粉末衍射数据与JCPDS标准卡片符合得很好,这表明我们合成的材料是碱土金属硅酸盐,属于正硅酸盐体系。在对掺Dy3+荧光粉的光谱分析可知,样品的吸收峰位于325nm、350nm、365nm和386nm附近,分别对应Dy3+离子6H15/2→6P3/2,6H15/2→6P7/2,6H15/2→6P5/2,6H15／2→4M21/2的跃迁。其用386nm紫外光激发,在位于480nm、492nm、575nm附近出现发射峰,分别对应于Dy3+离子4F9／2→6H15／2的跃迁,579nm对应于Dy3+离子4F9／2→6H13／2的发射跃迁。制备了Dy3+,Eu3+共掺杂样品,对其的光谱分析表明,明显增加了红光区发射此外还有橙色光590nm、红色光616nm、653nm、704nm处的发射,以上均为Eu3+的5D0→7FJ(J=1,2,3,4)能级的跃迁发射。稀土Eu3+离子的加入对样品发光所对应色坐标及色温影响较大。合成并分析了二元系碱土金属阳离子样品(MgxCa1-x) 2SiO4:Dy3+,Eu3+的紫外光谱特性,研究了碱土离子比例不同对光谱及色坐标的影响。本论文中图23幅,表8个,参考文献45篇。更多还原

【Abstract】 Silicate matrix has good chemical stability and thermal stability. People have focused a lot of attention on the research and development of silicate phosphor matrix for a long time. Due to the high lumens efficiency, good color reproduction characteristics of single matrix white phosphor, the research on it has great significance.In this paper, series samples of white LED phosphor M2SiO4:Dy3+, Eu3+(M= Mg, Ca) have been synthesized by high temperature solid state, and the corresponding structure characteristics and near-UV excited luminescent properties of the samples were studied.The X-ray powder diffraction data of series samples M2SiO4: Dy3+,Eu3+(M= Mg, Ca) have good agreement with JCPDS standard card, which shows that the synthetic material is alkaline earth metal silicate, belonged to silicate system.The excitation spectra of Ca2SiO4:Dy3+ show strong absorption near 325nm,350nm, 365nm and 386nm due to H15/2→6P3/2,6H15/2→6P7/2,6H15/2→6P5/2,6H15/2→4M21/2 transition of Dy3+. The emission light is at about 480nm、492nm、575nm under 386nm UV excitation. The emission at 482nm and 492nm (Blue) attribute to the 4F9/2→6H15/2 transition and 579nm (Yellow) attributes to the 4F9/2→6H13/2 transition.Series samples of co-doped Dy3+, Eu3+ M2SiO4 (M=Mg, Ca) have been synthesized. The spectra show that in addition to Dy3+ emission bands in blue and yellow of the characteristic peak, there are four other peaks at orange area 590nm, red area 616nm,653nm,704nm due to the Eu3+ in the 5D0→7FJ(J=1,2,3,4). Red light district of emission has been enhanced. The doped rare earth ions Eu3+ luminescence of samples has great impact in color coordinates (CIE) and color temperature.Still we prepared (MgxCa1-x)2SiO4: Dy3+,Eu3+ phosphors and analyzed under UV excitation. Different ratios of alkaline earth ions in the sample affect the spectrum and the color coordinates (CIE).There are 23 figures,8 tables and 45 references in this paper.更多还原