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.

与由具有均匀材料成分的颗粒组成的传统粉末荧光粉相比，由 AlN 基质中的 GaN 量子点或量子阱组成的 GaN 基纳米结构嵌入颗粒由于载流子而具有更高的发光效率作为制备这种颗粒的基本技术，气相法已经证明了以下三个过程：(1)首先通过汽化的Al和N_2气体在100℃下反应形成AlN颗粒。虽然在1100℃下制备的样品是AlN颗粒和未反应的Al的混合物，但在T_1高于1150℃时制备的样品是单相AlN。从生产高质量AlN颗粒的角度来看，1200℃的反应温度是有利的。(2)在第二步中，通过以下方式在AlN核颗粒上生长GaN： GaCl和NH_3在第二个反应器中在1000℃下反应可以看出，AlN核的颗粒直径从0.1μm增加到0.2μm，由此制备的GaN/AlN双层颗粒表现出以带边发射为主的阴极发光。 GaN，表明过度生长的 GaN 具有高结晶质量。(3) 通过 AlCl_3 和 GaN 的反应，在 GaN 颗粒表面沉积了 AlN。第二反应器下游部分的 NH_3 表现出由 GaN 的带边发射主导的光致发光 (PL)。AlCl_3 供给速率对 PL 特性的依赖性表明表面势垒对激发载流子和钝化的影响。到表面缺陷。