B离子对SiO2基质凝胶中Eu3+特征光谱的加强作用

使用正硅酸乙酯、硼酸和硝酸铝为前驱体，硝酸铕为掺杂剂，以溶胶-凝胶法制备了Eu单掺和Eu、B共掺的SiO2干凝胶，并成功地在钠钙玻璃上制备了光洁度很好的掺杂SiO₂多层薄膜.利用荧光光谱、红外光谱（IR）、X射线衍射（XRD）等技术研究了B离子、退火温度对样品发光性能的影响.荧光光谱显示发光体能产生很强的红色发光，经500℃以上退火处理，产生6条谱带，分别归属于Eu³⁺的⁵D₀→⁷F_J（J=0, 1, 2, 3, 4）的电子跃迁, ⁵D₀→⁷F₁的跃迁分裂为两个峰.实验结果表明，B离子的加入，由于在材料中形成了Si-O-B键，使Eu³⁺的配位环境的对称性降低，加强了Eu³⁺的红光发射.退火处理改变了材料的网络结构，降低了水和羟基的含量有助于提高发光强度，但退火温度太高（850℃），发生了荧光猝灭效应，源于稀土离子发生位置迁移形成的团簇.XRD测试结果显示材料是非晶态的.

Enhanced Emission From Eu3+;in B Ions Doped Sol-gel SiO2 Phosphors

Eu single doped and Eu,B co-doped SiO_2 xerogels and films were prepared by sol-gel process,using tetraethoxy silane,boric acid and aluminium nitrate as precursors,europium nitrate as the dopant.The influence of B ions and annealing temperature on luminescent properties of phosphors has been studied using fluorescence spectrum,X-ray diffraction and IR spectrum.The phosphors showed prominent luminescent in red.When heated up to 500℃,the emission spectrum showed six characteristic emission peaks,due to the electronic transition of ~5D_0→~7F_J(J=0,1,2,3,4)for Eu~(3+) respectively and the electronic transition of ~5D_0→~7F_1 was splited two peaks.When B ions were introduced to the Eu doped samples,the red Eu~(3+) emission was enhanced remarkably.This is because Si-O-B bonds were formed in the luminescent materials,and the symmetry of network was breached.Annealing changed the network structure and reduced the content of-OH and water,which benefits intensity of emission from Eu~(3+).The intensity of emission from