InGaN基蓝绿光LED外延材料与器件的研究

项目名称： InGaN基蓝绿光LED外延材料与器件的研究

项目编号： No.61475110

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 李学敏

作者单位： 太原理工大学

项目金额： 80万元

中文摘要： 蓝、绿光LED有源区的InGaN/GaN量子阱中，GaN与衬底间存在着较大的晶格失配及热失配，阻碍了蓝、绿光LED发光效率提高。本项目以减小有源区中的压电极化场和位错密度从而提高发光效率为目标，提出用InGaN代替目前GaN基LED结构中普遍使用的GaN形核层和非故意掺杂层，并生长以InxGa1-xN/InyGa1-yN量子阱充当有源区的蓝、绿光LED结构，研究：1）InGaN形核层和非故意掺杂InGaN层的位错生成、发展机制；2）高晶体质量和高电导率的n-InGaN和p-InGaN层的生长和掺杂机理；3）以InxGa1-xN/InyGa1-yN为有源区的蓝、绿光LED的设计、生长；4）InxGa1-xN/InyGa1-yN为有源区蓝、绿光LED的发光性质和效率骤降效应与其In组分、微结构的关系。本项目有助于理解以InGaN代替蓝、绿光LED中GaN层后LED的生长过程和发光机制。

中文关键词： 发光二极管；InGaN；压电极化；发光效率；蓝绿光

英文摘要： A large lattice mismatch and thermal expansion coefficient mismatch exsit between GaN and the substrate in blue and green LEDs using InGaN/GaN quantum wells as active regions. This challenge leads to the presence of the larger LED piezoelectric polarization fields and a large number of defects and dislocations, limiting the luminous efficiency. This project suggests replacing GaN with InGaN as nucleation layer and unintentionally doped layer in GaN-based blue and green LED structure to reduce the piezoelectric polarization field and the dislocation density in these two and subsequent layers, and thus improve the luminous efficiency. Furthermore, we propose to use InxGa1-xN/InyGa1-yN multiple quantum well (MQW) as active region of blue and green LED structure. This project combines means of SEM, XRD, TEM, EL, PL, Hall measurement to study : 1) the mechanism of dislocation generation and development in InGaN nucleation layer and unintentionally doped InGaN layer; 2 ) the mechanism of growth and doping of n-InGaN and p-InGaN layer, and growth condition of n-InGaN and p-InGaN layer with high quality and high conductivity ; 3) design and growth of InxGa1-xN/InyGa1-yN layer as the active region of the blue and green LED; 4) The effect of In-component and micro structure on luminous efficiency and efficiency droop of droop of blue/green LED with acitve region of InxGa1-xN/InyGa1-yN MQW. This program will help to understand basic process and luminous of the blue/green LED structures in which GaN layers in traditional blue/green LED structures are replaced with InGaN, as well it will provide experimental and theorical data for the study of light efficiency enhancement of blue/green LEDs.

英文关键词： LED;InGaN;piezoelectric polarization;luminous efficiency;blue and green light