白光LED蓝光转换材料的发光特性研究

Luminescence Properties of White LED Blue Light Conversion Materials

用稀土氧化物作为原料，通过高能球磨与反应烧结的方法，在1300℃合成了高纯度的铈激活和铈、钆共激活的钇铝石榴石蓝光转换材料，采用X射线衍射分析了产物的晶体结构，采用发射光谱和激发光谱研究了基质中Ce^3＋的发光特性以及Gd件对它的影响。结果表明，产物为立方晶系的钇铝石榴石晶体，可以被蓝光有效激发，通过调整掺杂离子的摩尔浓度，荧光粉的发射波长可覆盖530-560nm的黄绿光范围。利用荧光粉转换法制备了白光LED（1ightemittingdiode，发光二极管），在工作电流为20mA、工作电压为3．5V的条件下，所制备的白光LED色坐标x=0．310，y=0．323，光效26．131m·W^-1，显色指数81．8，色温6605K。

Using rare earth oxides as raw materials, yttrium aluminum garnets activated by cerium and gadolinium ions were prepared by high energy ball milling and solid-state reaction at 1 300 ℃. The crystal structures of the products were studied by XRD, and the luminescence characteristics of Ce ion and the influence of Gd ion were studied by emission and excitation spectra. The results indicated that the products were yttrium aluminum garnet crystals of cubic system, and they were excited by blue light chips effectively. The emission peak of phosphors could change among 530-560 nm by adjusting the mole density of doping ions. The red shift of emission spectra could be interpreted with the configuration coordination figure White LEDs were fabricated by phosphor conversion. When electric current is 20 mA, and the working voltage is 3.5 V, the white light LED chromaticity coordinates are x=0. 310 and y=0. 323, the lumen efficiency is 26. 131 m · W-t, the color rendering index is 81.8, and the color temperature is 6 605 K.