Exploiting Enhanced Polarization from Optically-Pumped NMR of Semiconductors

*技术摘要*将光抽运电子与核磁共振检测相结合的一种新型光谱，称为OP核磁共振，正在开发并应用于一系列重要的直接能隙III-V半导体。OP核磁共振利用光学定向电子，这些电子耦合到周围的核自旋；然后可以观察到增强的核磁共振信号。与光学相关缺陷相关的缺陷位置和掺杂剂将被光谱识别。将探索极化转移方案，其中一个区域的信号增强通过核自旋扩散传播到其他区域，从而打开了OP核磁共振新应用的可能性。在这个项目中，理论和实验工作将与能带结构和自旋相关的光学跃迁的计算紧密结合，一个工业合作伙伴将帮助选择用于分析的异质结构设备。这项研究的附带好处将包括将这些方法应用于II-VI和IV族半导体的OP核磁共振现象模型。研究生将接受尖端光谱学技术方面的教育和培训，这使他们能够在包括激光、半导体设备、核磁共振/核磁共振光谱学在内的各种领域追求职业生涯，并积累化学、物理和工程方面的知识和经验。与工业伙伴合作的经验将是非常宝贵的，有助于帮助学生做出明智的职业选择，并为未来的研究机会提供联系。*非技术摘要*尖端光谱工具正在开发，将激光与核磁共振(或称核磁共振(一种与核磁共振在医学上使用的技术密切相关的技术)结合在一起，研究半导体。半导体材料具有巨大的经济和工业重要性，因为它们构成了电子元件和设备的基本构件。半导体是一种材料，它充当电子的“管道”，控制电子在材料内部的流动位置和方式，例如在计算机芯片或数码相机的像素中。通过将激光照射到半导体上，就产生了电子。了解这些光激发电子的行为对器件性能很重要，激光核磁共振技术被用来通过电子与周围环境的相互作用来监测电子自旋。在这个项目中，研究生将接受这些先进技术的教育和培训，使他们能够在各种领域(即激光、半导体设备、核磁共振/核磁共振光谱学)追求职业生涯，并积累化学、物理和工程方面的知识和经验。协作团队包括一个行业合作伙伴，从而为我们的学生提供真实世界的体验，并为该项目的高级(学术)人员提供更广泛的商业重点视角。

****Technical Abstract****A new type of spectroscopy combining optical-pumping of electrons with NMR detection, termed OPNMR, is being developed and applied to a series of important classes of direct-gap III-V semiconductors. OPNMR exploits the optically-oriented electrons, which couple to surrounding nuclear spins; enhanced NMR signals can then be observed. Defect sites and dopants related to optically-relevant defects will be spectroscopically identified. Polarization transfer schemes, whereby signal enhancements in one region travel via nuclear spin diffusion to other regions will be explored, opening up the possibility of new applications of OPNMR. Theory and experimental work will be closely coupled in this project with calculations of the bandstructure and spin-dependent optical transitions, and an industrial partner will assist in selection of heterostructure devices for analysis. Ancillary benefits of this research will include models of OPNMR phenomena for these methods to be applied to II-VI and Group IV semiconductors. Graduate students will be educated and trained in cutting-edge spectroscopy techniques, which enables them to pursue careers in a variety of areas including lasers, semiconductor devices, NMR/MRI spectroscopy, and it builds both knowledge and experience in chemistry, physics, and engineering. Experience working with an industrial partner will be invaluable to help students make informed career choices and to provide contacts for future research opportunities.****Non-technical Abstract****Cutting-edge spectroscopic tools are being developed that combine lasers with nuclear magnetic resonance, or NMR (a technique that is closely-related to MRI's used in medicine), to study semiconductors. Semiconductor materials are of enormous economic and industrial importance because these form the basic building blocks for electronic components and equipment. Semiconductors are a type of material that act as a "pipeline" for electrons, controlling where and how electrons flow inside the material, such as in computer chips or the pixels in digital cameras. By shining laser light onto the semiconductor, electrons are generated. Understanding how these photoexcited electrons behave is important to device performance, and the laser+NMR techniques are used to monitor the electron spins through their interactions with the surroundings. In this project, graduate students will be educated and trained in these advanced technologies, which enables them to pursue careers in a variety of areas (i.e., lasers, semiconductor devices, NMR/MRI spectroscopy), and it builds knowledge and experience in chemistry, physics, and engineering. The collaborative team includes an industrial partner thus offering real-world experience for our students, and a broader commercially-focused perspective to the senior (academic) personnel on this project.