碱金属、稀土元素掺杂对LiEu(SiO2)(1/6)W2O8荧光粉发光性能的影响

Luminescence properties of LiEu(SiO_2)_(1/6)W_2O_8 phosphor doped with alkali metals and rare earths

采用超声波喷雾热解法制备了红色荧光粉(Li1-aAa)Eu(SiO2)1/6W2O8,Li(Eu1-bLnb)(SiO2)1/6W2O8(A=Na,K;Ln=La,Y,Gd)。通过扫描电镜、X射线衍射、激发和发射光谱对所制样品进行分析,选择合适的实验条件可制备出颗粒呈实心球形、结晶度好、表面光滑、没有团聚现象、发光强度较高、粒径平均1μm左右且分布较窄的荧光粉样品。该类红色荧光粉激发主峰位于396 nm,次激发峰位于465 nm,发射主峰位于615 nm。随着碱金属离子半径的增加(Li+<Na+<K+),(Li1aAa)Eu(SiO2)1/6W2O8(A=Na,K)系列荧光粉的发光强度呈下降趋势。稀土离子Y3+、La3+和Gd3+掺杂时,使该系列荧光粉的发光强度显著提高。该类荧光粉色纯度非常高,适用于紫光、蓝光芯片的白光LED制造。

Red phosphor （Li1-aAa）Eu（SiO2）1/6W2O8 and Li （Eu1-bLnb）（SiO2）1/6W2O8（A=Na, K; Ln=La, Y, Gd） particles were prepared by ultrasonic spray pyrolysis. The luminescence characteristics of the particles were investigated with SEM, X-ray diffraction, excitation spectra and emission spectra. The particles were spherical shape, around 1 μm in diameter with narrow size distribution. Aggregation between particles was not observed. The phosphor particles had very high emission intensity. The main excitation peak of the particles was a characteristic intra-configurational 4f-4f emissive transition of Eu^3＋（^7F0→^5L6） transition at 396nm. The main peak for the emission spectra was a transition ^5D0→^7F 2 of Eu^3＋ at 615nm. Emission intensity of （Li1-aAa）Eu（SiO2）1/6W2O8（A=Na, K）phosphor showed a decreasing trend with increasing radius of ions （Li^＋〈Na^＋〈K^＋）. Emission intensity of Li （Eu1-bLnb）（SiO2）1/6W2O8（Ln=La, Y, Gd） could be improved evidently when doped with Y^3＋, La^3＋ and Gd^3＋. The phosphor showed red emission with good color purity under 396nm and 465nm light excitation. The phosphor may be used for white-LED excitated by ultraviolet and blue chip.