白光LED用石榴石相氮氧化物荧光粉的制备及表征

Preparation and characterization of garnet phase oxynitride fluorescent powder for white light LED

为提高白光LED的显色指数,降低色温,采用阳离子协同替换的方式,在YAG石榴石相中引入N^(3-)的方式,合成一种新型可被蓝光LED激发的石榴石相结构的氮氧化物荧光粉。利用高温固相法合成了Ce^(3+)掺杂的Y_(2.94-x)Zr_xAl_(5-y)Si_yO_(12-z)Nz∶0.06Ce^(3+)(YZASON∶0.06Ce^(3+))(x=y=0.5、x=1,y=0.5、x=y=1)荧光粉,采用XRD、荧光光谱仪等表征手段对所制备的荧光粉的晶体结构与发光性能进行表征;并考察了原料投料量和助熔剂种类等对共生相的影响。结果表明,所制得的荧光粉是石榴石相和Zr_(0.72)Y_(0.28)O_(1.862)共生相的两相结构,并几乎不受原料投料量和助熔剂种类变化的影响;发射光谱相对于YAG∶Ce^(3+)荧光粉有明显的红移,最大红移量26 nm左右;热猝灭较小;在色坐标上相对于在黄绿光区域和色温较高的YAG∶Ce^(3+)荧光粉,能够表现出黄光且色温也较低(CCT<6 000 K)。

In order to improve the color rendering index and reduce the color temperature of white LED,a novel oxynitride fluorescent powder that presents a structure of garnet phase and can be motivated by blue LED is prepared by incorporating N^（3-）into YAG garnet phase via the cooperative substitution of ions. The Ce^3＋doped,white emitting Y（2.94-x）ZrxAl（5-y）SiyO（12-z）Nz∶0.06 Ce^3＋（ YZASON ∶0. 06 Ce^3＋）（ x=y= 0. 5; x= 1,y= 0. 5; x = y = 1） oxynitride fluorescent powder is synthesized via high temperature solid phase reaction method.X-ray diffraction（ XRD） and fluorescence spectrometer are used to characterize the crystal structure and luminescence properties of the synthesized fluorescent powder. The influences of the addition amount of raw materials and the varieties of fluxing agent on the symbiotic phases of sample are investigated.The results show that the obtained fluorescent powder is composed of two phases including YAG garnet phase and Zr（0. 72） Y（0. 28） O（1. 862） symbiotic phase,which is hardly affected by changes of either addition amount of raw material or varieties of fluxing agent.The emission spectrum shows obvious red shift compared with YAG ∶ Ce^3＋fluorescent powder and the maximum red shift amount is about 26 nm.The thermal quenching effect of the obtained fluorescent powder is smaller.It exhibits yellow light and lower color temperature（ CCT 〈6 000 K） compared with the YAG ∶ Ce^3＋ fluorescent powder which locates at yellow-green light emission range on the color coordinate and exhibits a higher color temperature.