GaAs基半导体激光器具有优异的光电特性，在光通信、材料加工及国防等领域中有着重要的应用。针对其阈值电流高、转化效率低等关键性问题，基于能带理论，本项目在有源区中引入了一种脊型量子阱/量子点复合结构，但其界面结构是影响器件性能的关键因素之一。本项目围绕复合结构调控的关键问题展开以下研究：1）理论设计和生长量子阱/量子点复合结构的GaAs基外延材料；2）亚埃水平级研究材料复合结构及界面原子生长动力学行为及界面形成演变机制，掌握原子排布及迁移规律，实现复合结构的可控生长；3）研究界面结构及其成分与载流子输运性能之间的关系，阐明复合结构及其界面结构对器件性能的影响规律，为制备高功率、低阈值以及高光谱特性的GaAs基半导体激光器的研究提供新思路和理论基础。

GaAs based semiconductor laser has excellent photoelectric properties and has important applications in the field of optical communication, material processing and national defense. For its high threshold current, low conversion efficiency and key issues, we introduced a ridge in the active area type/quantum dot composite quantum well structure based on band theory. However, the interface structure is one of the key factors which have influence on the device performance. This project focuses on the key issues of the control of the composite structure as follows: 1) Quantum well/dot composite structure epitaxial material is theoretically designed and grown. 2) Material composite structure and its atomic growth dynamics behavior and interface form evolution mechanism are studied at the sub-angstrom level. Atomic arrangement and migration rule are mastered in order to realize the controllable growth of composite structure; 3) The relationship between structure and composition of interface and carrier transport properties is studied. The influence of composite and interface structures on the device performance is elucidated. The research of GaAs semiconductor laser provides new ideas and theories for obtaining high power, low threshold, and high spectral characteristics.