Molecular beam epitaxial growth of terahertz quantum cascade lasers

太赫兹量子级联激光器的分子束外延生长

• 批准号: 2883727
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2883727
• 关键词: Molecular; beam; epitaxial; growth; terahertz

This project will focus on the molecular beam epitaxial (MBE) growth of GaAs-AlGaAs terahertz-frequency (THz) quantum cascade lasers (QCLs). Despite the many applications that would benefit from such a high-power THz source, ranging from high bandwidth communications and satellite sensing through to non-destructive testing in the manufacturing sector, currently all THz QCLs need to operate at cryogenic temperatures, which limits their exploitation. The project will make a step change in the take-up of THz technologies, working in collaboration with international partners and industry, by demonstrating Peltier-cooled THz QCL operation with high output powers, and the first-ever room temperature THz QCL. During the project, the candidate will become an expert in the growth of semiconductor structures by MBE, as well as gaining extensive experience in device modelling, device fabrication, and electrical and optical characterisation of lasers. They will use MBE techniques to grow THz QCLs, each of which has more than 1000 separate layers, patterned with atomic monolayer precision. They will perform systematic comparisons between different heterostructure designs, including investigating the effect of barrier height and doping on performance, as well as optimising the growth conditions such as substrate temperature, and III/V flux ratios. The project will be underpinned by detailed growth characterisation using techniques such as in situ flux measurements and optical pyrometry, as well as ex situ X-ray diffraction. This will ensure long-term reproducibility between different wafer growths. All material will be processed into lasers using the nanotechnology cleanroom in the University's new Bragg Centre for Materials Research before being testing electrically and optically in the School's terahertz laboratories. Results will be compared with simulations to enable optimisation of performance of lasers operating between 2 THz and 5 THz.

该项目将集中于GAAS-Algaas Terahertz频率（THZ）量子级联激光器（QCLS）的分子束外延（MBE）生长。尽管有许多高功率THZ来源受益的应用，从高带宽通信和卫星传感到制造业中的非破坏性测试，目前，目前所有THZ QCL都需要在低温温度下运行，从而限制了其剥削。该项目将通过展示具有高输出功率的Peltier-Cool thz QCL操作和有史以来第一个室温THZ QCL的Peltier-Clier-Clt THZ QCL操作，从而改变THZ Technologies的采用，与国际合作伙伴和行业合作。在项目期间，候选人将成为MBE的半导体结构增长的专家，并在设备建模，设备制造以及激光器的电气和光学表征方面获得丰富的经验。 他们将使用MBE技术来生长Thz QCL，每个QCL具有1000多个单独的层，并具有原子单层精度。他们将在不同的异质结构设计之间进行系统的比较，包括研究屏障高度和掺杂对性能的影响，以及优化诸如底物温度和III/V频率之类的生长条件。该项目将使用诸如原位通量测量和光学上的诸如原位通量测量以及Ex X射线衍射的技术来支持该项目的基础。这将确保不同晶片生长之间的长期可重复性。所有材料都将使用大学新布拉格材料研究中心的纳米技术清洁室处理为激光器，然后在学校的Terahertz实验室进行电和光学测试。结果将与模拟进行比较，以优化2 THz和5 THz之间的激光器的性能。