半导体激光器具有成本低、体积小、寿命长等优点，正在兴起的激光显示技术迫切需要高性能的GaN基绿光激光器。绿光InGaN量子阱有源区是GaN基绿光激光器的核心结构，它的晶体质量和光学性质直接决定了器件性能。绿光InGaN量子阱生长温度低、晶格失配大，InGaN量子阱的界面易形成trench缺陷，是限制GaN基绿光激光器效率提升的瓶颈之一。目前关于trench缺陷的研究还很少。我们此前的研究表明trench缺陷的形成与In组分偏析有密切关联，但其微观形成机制还有待研究。本项目拟深入研究GaN基绿光激光器InGaN量子阱有源区trench缺陷的微观结构与形成机理，研究绿光InGaN量子阱的MOCVD生长动力学和热力学，探索抑制InGaN量子阱中trench缺陷形成的外延生长技术，实现高发光效率、低非均匀展宽的绿光InGaN量子阱，为研制高效率的GaN基绿光激光器奠定基础。

Semiconductor laser diodes (LDs) have been widely used in the field of laser-based displays, because of its low-cost, small size, and long lifetime. High-performance GaN-based green LDs are desirable for laser-based displays. The epitaxial growth of InGaN quantum well (QW) active region with high efficiency and narrow full-width-half-maximums (FWHMs) is a key point to realize LDs with good performances. However, InGaN QW emitting in the green spectrum range, which needs to be grown at low temperature with large mismatch, usually shows high density of trench defects in the interface, which is one of the limitation to improve the performance of GaN-based green LDs. Few studies on trench defects have been reported. Our previous results showed that the formation of trench defects is closely related with In segregation, but the formation mechanism needs further study. In this proposal, we propose to study in details the microstructure and the formation mechanism of trench defects in green InGaN QW. We will also study the dynamics and thermodynamics of MOCVD growth of green InGaN QW, in order to develop new epitaxial growth method to suppress the formation of trench defects. Based on these studies, green InGaN QW with high efficiency and better uniformity will be obtained, and thus the performance of GaN-based green LDs will be improved.