CaGd2（MoO4）4:Sm3+,La3+荧光粉的制备及发光性能研究

Synthesis and Photoluminescence Properties of CaGd2（MoO4）4:Sm3+,La3+ Phosphors

采用高温固相法合成了CaGd2-x(MoO4)4:x Sm^3+(x=0. 1、0. 3、0. 5、0. 7、0. 9)橙红色荧光粉。研究了样品的X射线衍射谱(XRD)、激发光谱和发射光谱。从XRD图谱测试结果表明,在900℃下烧结6 h后得到的样品为纯Ca MnO4晶相,样品CaGd2(MoO4)4:Sm^3+的激发光谱由两部分组成:一部分(250~340) nm为属于O2^--M6O+的电荷迁移带;另一部分(350~450) nm的系列线状峰是Sm3+的f-f跃迁特征激发峰。样品在405 nm(6H5/2→4F7/2)下激发得到的发射光谱,其主发射峰位于646 nm(6G5/2→6H7/2)处。当Sm3+掺杂浓度高于2%时,样品CaGd2-x(MoO4)4:x Sm^3+发生浓度猝灭现象,该现象是由于离子间的能量传递。在CaGd1. 5(MoO4)4:0. 5Sm^3+样品中掺入一定浓度La^3+,掺入La^3+并没有改变CaGd2(MoO4)4:Sm^3+光谱峰的形状和位置,当y=0. 8时,荧光粉的发光强度最好。通过测量计算GIE在405 nm激发下的色坐标,显示色坐标均在橙红色区域移动,表明荧光粉的光色性较好。

CaGd2-x( MoO4)4: x Sm^3+( x = 0. 1,0. 3,0. 5,0. 7,0. 9) orange-red phosphor was synthesized by high temperature solid state method. The crystal structure and luminescence properties of the samples were characterized by means of X-ray diffraction and photoluminescence spectra. The results show that the synthesized samples were pure Ca MoO4 crystal phase when the calcination temperature at 900 ℃ for 6 h. The excitation spectrum consists of two parts: the intense broad band from 250 nm to 340 nm,and the other includes several sharp lines from 350 nm to 450 nm. The former board band is attributed to charge transfer( C-T) transition of O2-Mo6^+,while the sharp peaks are assigned to intra-configurational f-f transitions of Sm3^+. Under the excitation spectrum of 405 nm(6 H5/2→4 F7/2),the emission spectra of the CaGd2-x( MoO4)4:x Sm3+phosphors the stronger peak appear at 646 nm(6 G5/2→6 H7/2) as red emission. The sample CaGd2-x( MoO4)4: x Sm3+happens concentration quenching when the concentration of Sm3+is 2%. Analysis show that the concentration quenching mechanism is the energy transition among the nearest neighbor between ions. After adding a certain concentration of La3+into CaGd1. 5( MoO4)4: 0. 5 Sm^3+,the incorporation of La^3+in CaGd2( MoO4)4: Sm3+fluorescence can’t change the shape and position,when the y for La^3+is 0. 8,the samples fluorescence powder have the best luminous intensity. By measuring and calculating the color coordinates of GIE under 405 nm excitation,the display color coordinates all move in the orange-red region,indicating that the phosphor has a good photochromatic.