摘要
以MgMoO_4为基质,Eu^(3+)为激活剂,NH_4Cl为助熔剂,采用高温固相法合成白光LED用MgMoO_4:Eu^(3+)红色荧光粉。通过差示扫描量热与热重分析(DSC/TG)研究合成荧光粉的最佳温度,利用X射线衍射仪(XRD)、扫描电镜(SEM)和傅里叶红外光谱仪(FT-IR)研究荧光粉的结构,并用荧光光谱仪对荧光粉的发光效果进行检测。结果表明:用NH_4Cl作为助熔剂,合成MgMoO_4:Eu^(3+)荧光粉的最佳温度为900℃。添加NH_4Cl后,MgMoO_4:Eu^(3+)荧光粉的结构得到优化,颗粒呈椭球形,粒径约为0.5~1μm。395 nm和465 nm波长激发的发射光谱由一系列尖峰组成,分别位于592 nm(~5D_0→~7F_1),615 nm(~5D_0→~7F_2)和699 nm(~5D_0→~7F_4)处,其中615 nm处的发射峰强度最大,属于Eu^(3+)的超灵敏电偶极跃迁。添加NH_4Cl可明显提高MgMoO_4:Eu^(3+)荧光粉的激发与发射峰的强度,最佳添加量(n(NH_4Cl)/n(MgO))为1%,此时发射光谱的强度是未添加NH_4Cl时的7倍左右,395 nm激发的发射光谱对应的最佳Eu^(3+)浓度为0.1,465 nm激发的发射光谱对应的最佳Eu^(3+)浓度为0.15。
The MgMoO4：Eu^3＋ red phosphors used in white light LED were synthesized by the high temperature solid-state reaction method using MgMoO4 as matrix, Eu^3＋ as activator and NH4C1 as flux. The optimum temperature for the synthesis of phosphor powder was studied by a thermogravimetric analyzer （DSC-TG）. The intemal structures and surface topographies were tested by X-ray diffraction （XRD）, scanning electron microscope （SEM） and Fourier Transform Infrared spectrometer （FT-IR）. The luminescence of the crystal was detected by fluorescence spectrometer. The results show that, the optimum synthesis temperature of MgMoO4：Eu^3＋ red phosphors is 900℃ using NH4Cl as flux. With the addition of NH4Cl adding, the structure of the synthetic product is optimized, while the particles are ellipsoid and the size is about 0.5-1μm. The emission spectrum is composed of a series of peaks at 592 um （SD0→7F1）, 615 nm（SD0→7F2） and 699 nm（SD0→7F4）. The largest emission peak is located at 615 nm, which belongs to super sensitive electric dipole transition of Eu3＋. The addition of NHaCI can significantly enhance the excitation and emission peak intensity of MgMoO4：Eu3＋ red phosphor, and the best amount （n（NH4Cl）/n（MgO））is 1%, at which the emission spectrum intensity is about 7 times of that of phosphor with NH4Cl. The best content of Eu^3＋is 0.1 for the emission spectra excited for 395 nm and 0.15 to that excited at 465 nm.
作者
朱德生
姜锋
ZHU Desheng JIANG Feng(School of Materials Science and Engineering, Central South University, Changsha 410083, China Light Alloy Research Institute, Central South University, Changsha 410083, China School of Physics and Optoelectronic Engineering, Yangtze University, Jingzhou 434025, China)
出处
《粉末冶金材料科学与工程》
北大核心
2017年第3期414-421,共8页
Materials Science and Engineering of Powder Metallurgy
基金
长沙市科技重大专项(K080105-11)
国家自然科学基金资助项目(11304023)
