Development of group-III- nitride-based nanostruchue-embedded phosphor particles

III族氮化物基纳米结构嵌入荧光粉颗粒的开发

基本信息

批准号：
17360138
负责人：
HARA Kazuhiko
金额：
$ 8.29万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

项目摘要

In contrast to the conventional powder phosphors consisting of particles with a uniform material composition, GaN-based nanostructure-embedded particles, which consist of GaN quantum dots or quantum wells in the AlN matrix, has been proposed to have higher luminescence efficiencies owing to the carrier confinement effect. As a fundamental technique to fabricate such particles, the following three processes have been demonstrated by using the vapor phase method.(1) The AlN particles were first formed by a reaction of vaporized Al and N_2 gas at temperatures (T_1) from 1100 to 1250℃ in the first reactor. Although the sample prepared at 1100℃ is a mixture of AlN particles and unreacted Al, those prepared at T_1 higher than 1150℃ are a single phase AlN. It was found that the reaction temperature of 1200℃ is favorable from a viewpoint of producing the high quality AlN particles.(2) At the second step, GaN was grown on the AlN core particles by a reaction of GaCl and NH_3 at 1000℃ in the second reactor. It can be seen that the particle diameter was increased from 0.1-0.2 μm for the AlN core. Thus fabricated GaN/AlN bilayer particles showed cathodoluminescence dominated by the band edge emission of GaN, indicating a high crystalline quality of the overgrown GaN.(3) AlN was deposited on the surface of GaN particles by a reaction of AlCl_3 and NH_3 in the downstream part of the second reactor. AlN-coated particle showed photoluminescence (PL) dominated by the band edge emission of GaN. The dependence of AlCl_3 supply rate on the PL property suggests the effects of surface barrier to the excited carriers and passivation to surface defects.

与由具有均匀材料组成的颗粒组成的常规粉末磷相反，基于GAN的纳米结构所包含的颗粒，该颗粒由ALN基质中的Gan量子点或量子孔组成，它已被提议具有较高的发光效率。作为制造此类颗粒的基本技术，通过使用蒸气相法证明了以下三个过程。（1）在第一个反应堆中，ALN颗粒在温度为1100至1250℃时首先是通过温度从1100到1250的蒸发Al和N_2气体反应形成的ALN颗粒。尽管在1100℃处制备的样品是Aln颗粒和未反应的Al的混合物，但在T_1高于1150℃的T_1中制备的样品是单相ALN。发现从产生高质量ALN颗粒的角度来看，1200℃的反应温度是有利的。（2）在第二步中，在第二个反应堆中通过GACL和NH_3的反应在ALN核心颗粒上生长了GAN。可以看出，对于ALN核心，颗粒直径从0.1-0.2μm增加。制造的gan/aln双层颗粒显示了以gan的带边缘发射为主的阴极发光，表明在第二反应器的下游部分中，Alcl_3和nh_3的反应将Aln的高晶体质量沉积在GAN颗粒表面上。 Aln包涂的粒子显示的光量（PL）以GAN的带缘发射为主。 ALCL_3供应率对PL特性的依赖性表明表面屏障对激发载体的影响以及对表面缺陷的钝化。