图形化衬底上AlGaInAs量子点的MOCVD生长研究

VCSEL作为芯片级原子钟的核心部件，决定了芯片级原子钟系统的性能。然而在高温下，量子阱结构有源区的增益特性必然有所降低，这将导致VCSEL器件性能的下降，制约了芯片级原子钟的发展。因此，非常有必要开发具有高增益特性、低温度依赖的有源区结构用于实现高性能的VCSEL器件。. 本项目旨在利用“非对称效应”实现具有“polarization-dependent gain”特性的AlGaInAs量子点的MOCVD外延生长。利用图形化模板衬底实现量子点大小、位置、密度以及组份的精确可控；并研究图形衬底上量子点的成核机制、表面形貌演变等生长动力学特性；分析生长参数、图形结构与量子点质量及光学特性各向异性的关系；优化相关参数，最终实现高温时(80℃)，发光峰为795 nm、发光线性极化度>90%的AlGaInAs量子点；为实现低阈值、偏振稳定的芯片级原子钟用量子点VCSEL器件奠定基础。

As the core component of chip-scale atomic clock, if the performance of VCSEL is further improved, it will be greatly promote the development of chip-scale atomic clock performance. However, the gain characteristics of the quantum well structure inevitably reduced at high temperatures, which causes the quantum well based VCSEL device with lower light output power, higher threshold and power consumption. Therefore, it is necessary to develop a active region with higher gain characteristics and lower temperature dependence for VCSEL devices.. This project aims to realize a asymmetric AlGaInAs quantum dot (QD) with polarization-dependent gain characteristics. The size, location and density of (Al)GaAs QDs are precise control by using patterned substrates. The research focus on the relationship of the growth parameters and the emission anisotropic of QD. By varying the MOCVD growth parameters to achieve a asymmetric quantum dot with the emission peak at 795 nm and linear polarization degree of greater than 90%. Lay the foundation for quantum dot based VCSEL device.