Zr^4+取代对Ba(Mg1/3Nb2/3)O3:Eu^3+荧光粉结构和荧光特性的影响

Effect of Zr^4+ Substitution on Structure and Luminescence Properties of Ba(MgNb)O:Eu^3+ Phosphors

采用固相法制备了不同Zr^4+取代量的(Ba0.97Eu0.03)(Mg(1-x)/3Nb2(1-x)/3Zrx)O3荧光粉,研究了Zr^4+取代量对荧光粉的晶体结构以及荧光特性的影响规律。随着Zr^4+取代量的增加,当x=0.05时,体系发生了从六方相到立方相的转变,发光行为有所减弱;当x>0.05时,体系为立方相,Zr^4+的引入使BO6八面体扭转程度增强,能级简并消除,B—O成键范围变大,基质对近紫外光区域的光吸收增强,来源于基质的电荷迁移带强度增加,增强了对Eu^3+的敏化作用,使稀土Eu^3+在近紫外与蓝光区域的激发与发射均得到增强。Zr^4+取代后,荧光粉的色坐标由从(0.658,0.342)移动到(0.642,0.358),是一种适用于近紫外(395 nm) LED芯片激发的红色荧光粉。

(Ba0.97Eu0.03)(Mg(1-x)/3Nb2(1-x)/3Zrx)O3 phosphors were prepared via a solid-state route.The crystal structure and luminescent properties were investigated.A phase structure transformation from hexagonal to cubic occurs as Zr^4+content (x)increases to 0.05,thus weakening the luminescence properties.When x>0.05,the crystal structure is cubic.The introduction of Zr^4+into the phosphor increases the tilting of BO6 octahedron,which makes the energy level split and broadens the bonding energy range of B—O bond,thus enhancing the absorption of near ultraviolet (NUV) light and increasing the intensity of charge transfer band(CTB).The CTB intensity increases the sensitization effect of the host on Eu^3+and improves the luminescent properties in NUV and blue light regions.The chromaticity coordinate of the phosphor shifts from (0.658,0.342) to (0.642,0.358) due to Zr^4+substitution,indicating its potential application in the excitation of NUV (395 nm) LED chips.