白光LED用新型红色荧光粉Li_2SrSiO_4:Eu^(3+)的合成及性质  

Synthesis and Properties of Novel Red-emitting Phosphor Li_2SrSiO_4:Eu^(3+) for White LED

作　　者：翟永清[1] 王欣[1] 冯仕华[1] 刘毅兰[1] 游志江[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：《材料工程》2011年第3期24-27,共4页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(20675023)

摘　　要：以金属硝酸盐为原料,正硅酸乙酯为硅源,采用凝胶-燃烧法合成了新型红色荧光粉Li2SrSiO4:Eu3+,用红外分光光度计、X射线粉末衍射仪、荧光分光光度计等手段研究了该荧光粉的形成过程、结构及发光性能。结果表明:凝胶燃烧所得前驱物在700℃焙烧3h即得目标产物Li2SrSiO4:Eu3+,其晶体结构属六方晶系,空间群为P3121,晶胞参数:a=0.5012nm,c=1.2360nm;激发光谱为一宽带,最大激发峰位于396nm处;最强的发射峰位于618nm处,是典型的Eu3+的5D0→7F2跃迁导致的;当Eu3+掺杂摩尔分数x在0.04~0.24的范围内时,随Eu3+浓度的增加,发光强度逐渐增强,无浓度猝灭现象发生。由于该荧光粉能够有效吸收396nm附近的近紫外光,因此适合做350~410nm InGaN管芯激发的白光发光二极管用高亮度红色荧光粉。A novel red-emitting phosphor Li2SrSiO4：Eu3＋ was synthesized by gel-combustion method,using the metal nitrates as raw materials,and tetraethoxysilane as silica source.The formation process,structure and luminescence properties of as-synthesized Li2SrSiO4：Eu3＋ were investigated by FI-IR,XRD and fluorescence spectrophotometer respectively.The results show that the goal product Li2SrSiO4：Eu3＋ can be obtained after the precursor obtained from the combustion of dry gel was calcined at 700℃ for 3h.The as-synthesized sample has hexagonal crystal structure and P3121 space group,and unit cell parameter is a=0.5012nm,c=1.2360nm.The excitation spectrum shows a broad band,and the strongest excitation peak is at 396 nm.The strongest emission peak is at 618 nm,which is ascribed to 5D0→7F2 characteristic transition of Eu3＋.When the mole fraction x of doped Eu3＋ is in the range of 0.04-0.24,the luminescence intensity of the sample increases gradually with the the increase of Eu3＋ concentration.It is interesting that no concentration quenching occurs.The synthesized phosphor can absorb near-UV light around 396nm effectively,so it is a suitable red-emitting phosphor for white light-emitting diodes excited by 350-410nm InGaN chip.

关 键 词：Li2SrSiO4:Eu3+ 红色荧光粉 白光发光二极管 凝胶-燃烧法 

分 类 号：TH117.3[机械工程—机械设计及理论]