氮化镓发光二级管蓝光转换材料的合成和发光性质

合成了Ce3＋掺杂的稀土石榴石结构复合氧化物体系(Y1-xGdx)3Al5O12、(Y1-xLux)3Al5O12、(Y1-xLax)3Al5O12、(Y1-xYbx)3Al5O12和(Y1-xTbx)3Al5O12.重点研究了(Y1-xGdx)3Al5O12:Ce3＋和(Y1-xLux)3Al5O12:Ce3＋两个体系的晶体结构和发光性质.这些体系都具有立方石榴石结构.(Y1-xGdx)3Al5O12:Ce3＋体系随Gd取代Y,晶胞参数略有增加.荧光光谱的发射波长随Gd浓度增加发生红移,当x=0.5时发射波长达到最大值（560 nm）,并不再随Gd含量增加而变化. (Y1-xLux)3Al5O12:Ce3＋的晶胞参数随 Lu取代Y而减小,但均保持了立方石榴石结构.荧光光谱的发射波长随Lu3＋的增加向短波方向移动,Lu3Al5O12:Ce3＋的发射波长的峰值为520 nm,体系的蓝移量是20 nm.利用分离发光中心的位形坐标模型对波长的移动作了定性解释.这两个体系的发射波长的可调节特性,对改善与氮化镓发光二极管(LED)匹配的蓝光转换材料的色坐标、色温等显色性质具有重要意义.

Synthesis and Luminescence of Gallium Nitride LED Blue Light Conversion Materials

A series of rare earth complex oxides, i.e. (Y1-xGdx)3Al5O12 : Ce3＋, (Y1-xLux)3Al5O12:Ce3＋, (Y1-xLax)3Al5O12:Ce3＋, (Y1-xYbx)3Al5O12:Ce3＋and (Y1-xTbx)3Al5O12:Ce3＋, have been prepared, and their luminescent properties were studied. Particular attention was paid to (Y1-xGdx)3Al5O12:Ce3＋ and (Y1-xLux)3Al5O12:Ce3＋systems because of their promising luminescent properties. X-ray powder diffraction patterns show that both systems have garnet structure, and the lattice constants vary smoothly with the compositions. The emission spectra of Ce3＋ in both systems are a broad band located at about 540 nm. The emission transition shows a red shift in (Y1-xGdx)3Al5O12:Ce3＋ system, and a blue shift also observed in (Y1-xLux)3Al5O12:Ce3＋system. This phenomenon could be interpreted with the configuration coordination model. The shift of the emission spectra in these systems provides the new option to improve the performance of white LED device.