光纤低损耗窗口拓展到1.26-1.68微米为海量光网络打开美好前景,相应光电材料和集成器件成为研究热点.在GaAs中掺入氮/铋形成稀氮/铋半导体,显著降低禁带宽度,保证带边不连续量、晶格常数等可调,却也引入深能级、界面态等不良影响,深入探究物理机制就成为关键.然而,由于传统表征技术局限,类稀氮低维结构界面激子行为与电子结构等关键特征参数并未能得到可靠研究..本项目利用特色红外光调制反射(PR)与调制光致发光(PL)光谱方法研究大变组分GaNAs/GaAs单量子阱,通过对PL光谱实验系统反射/透射式共生磁光测控功能拓展和磁光PL/变温PR分析,探究深能级和界面激子效应,掌握弱PL跃迁与氮组分关系及其随磁场演化,揭示峰位移动物理机制,获得电子结构与激子参数.从物理机制和材料参数两方面为类稀氮GaAs基半导体材料器件瓶颈性难题破解提供基础支持,提升光谱研究与保障水平.

The low-loss window of optical fiber extends to 1.26-1.68 microns and opens up a bright future for massive optical networks. Consequently, the corresponding optoelectronic materials and integrated devices have become research hotspots. Nitrogen/Bismuth is incorporated into GaAs to form a dilute nitride/bismide semiconductor, leading to significant reduction of band gap, ensuring the band-edge discontinuities and lattice constants be adjustable, while also introducing deep levels, interface states, and other adverse effects. The physical mechanism becomes the key, and it is also an important basis for understanding the properties of dilute nitrogen-like semiconductors. Unfortunately, critical characteristic parameters such as interfacial exciton behavior and electronic structure of dilute nitrogen low-dimensional structures have not been reliably studied, due to the limitations of traditional characterization techniques..The innovation of this project lies in the study of large-variable-component GaNAs/GaAs single quantum wells using our unique photoreflectance (PR) and infrared photoluminescence (PL) spectroscopy, the extension of the PL experimental system with the coexist of reflection- and transmission-mode magneto-optical condition, and the analysis by magneto-optical-PL and temperature-dependent PR. Assisted with magnetic exciton and effective-mass approximation simulation, the deep levels and interfacial excitonic effects of N will be explored, the relationship be investigated between the weak PL transitions and the nitrogen content as well as its evolution with magnetic field, the physical mechanisms of the peak shift be clarified, and the electronic structure and exciton parameters de determined. Basic support will be established from both the physical mechanism and the material parameters for the optimization of dilute-nitride GaAs-based semiconductor materials and devices.