高注入下GaN基紫光激光器的载流子输运及复合机制研究

项目名称： 高注入下GaN基紫光激光器的载流子输运及复合机制研究

项目编号： No.61474110

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： 刘宗顺

作者单位： 中国科学院半导体研究所

项目金额： 85万元

中文摘要： GaN基紫光激光器在高密度光存储、生化探测、材料加工等民用领域和在导弹近炸引信等国防领域均具有重要的应用前景，这些应用要求GaN基激光器在高注入状态下具有低阈值电压和高输出功率。本课题从GaN基激光器在紫光波段对应的量子阱较浅、限制作用较弱、阱中的载流子容易逸出并形成泄漏电流的特点出发，深入研究不同的注入水平下的载流子传输、复合和泄漏机制，包括多层耦合复杂量子阱结构对载流子限制作用的增强机制、高注入下激光器有源区内载流子的泄漏途径和调控手段、过量Mg掺杂在p-GaN中形成的深能级缺陷带和不同掺杂浓度下载流子在P型欧姆接触区域的输运过程等，通过对激光器的多量子阱有源区、电子阻挡层和P型掺杂区域的能带结构设计，以理论模拟和实验验证的方式实现对高注入状态下载流子分布和复合过程的功能调控，从而为实现低阈值电压、高输出功率的GaN基大功率紫光激光器提供理论基础和调控手段。

中文关键词： 高注入；氮化镓；激光器；紫光

英文摘要： GaN-based violet laser diodes have potential applications in the social and defense fields of high-density optical storage, biochemical detection, material process and missile proximity fuse. These applications demand low threshold voltage and high output light power of GaN-based laser diodes under high current density injection. Based on the characteristics of GaN-based laser diodes with emission wavelength in the violet region, such as the shallow quantum well, weak quantum-confinement and relatively greater probability to escape from the quantum wells and leak out, this proposal concentrate on the various mechanisms of carrier transport, recombination and leakage under different injection levels. The multi-coupled complex quantum wells are exploited to enhance the quantum confinement effect. The different leakage pathways of carriers in the multi-quantum well active region of laser diodes and corresponding adjustment methods are studied under high injection levels. Excess Mg atoms are doped in the p-GaN region to form deep-level defect and its related promoting effect to the transport processes of carriers across the p-doped region are theoretically investigated. The band structure of multi-quantum wells, AlGaN electron blocking layer and p-doped contact region are theoretically designed to optimize the carrier distribution and recombination under high injection levels. These theoretical and experimental results should benefit the development of GaN-based violet laser diodes with low threshold voltage and high output light power.

英文关键词： high injection levels;GaN;laser diodes;violet