NMR Studies of Optically Active Impurities under In Situ Illumination

这是俄勒冈州立大学的一位高级教授获得的一个新奖项，该项目将利用核磁共振（NMR）的局部化学特性来研究半导体和绝缘体中光学活性杂质的微观特性。固体核磁共振技术将与原位照明相结合，以检查光学激发对电子结构和与特定杂质相关的局部原子排列的影响。特别注意的是双稳定杂质，如Ga或In在CdTe和其他II-VI化合物以及CdF2。光增强的寄主（113Cd， 125Te和19F）核自旋晶格松弛将被用作双稳杂质转化为常规有效质量供体的指标。杂质种核磁共振，特别是69Ga，将与原位照明结合使用，以寻找杂质基态结构重排的直接证据。杂质种NMR （69Ga和63Cu）也将用于研究荧光粉中活性中心的局部环境，如SrS（Cu，M）和ZnS（Mn, Ga）。目标是阐明对这些杂质的微观理解，这将有助于这类材料的工程设计，用于特定的电子和光学应用。建议的实验将提供博士和硕士研究生教育和本科生研究机会的场所；它们也将以项目和演示的形式被利用来丰富现代物理学和固体物理学的本科课程。控制特定杂质的引入对于确定技术上重要的电子和光学材料的性质是至关重要的。俄勒冈州立大学（Oregon State University）的一位资深教授获得了这一奖项，以表彰他对一类具有光学活性的杂质的研究。这些杂质在被照射时改变其原子尺度的性质，或在主体材料中受到光照或电流时发光。这些材料的应用包括用于平板显示器和光学数据存储的发光元件。核磁共振（NMR）是一种光谱学，可以揭示材料中特定化学元素环境的原子尺度细节。在这项研究中，核磁共振将用于探测照明对宿主原子环境的影响，比如CdTe或CdF2中的Cd，或这些材料和平板显示器正在开发的荧光粉中的杂质，如Ga。这项研究和相关研究的目标是达到微观理解的水平，这将有助于这类材料的工程设计，用于特定的电子和光学应用。建议的研究将整合到本科和研究生教育中。博士和论文研究将培养毕业生进入美国高科技行业。本科生将参与俄勒冈州立大学现代物理学和固态物理学正规课程的研究和充实（项目和示范）

This is a renewal award to a senior professor at Oregon State University for a project that will exploit the local, chemically specific properties of nuclear magnetic resonance (NMR) to investigate the microscopic properties of optically active impurities in semiconductors and insulators. Solid-state NMR techniques will be combined with in situ illumination to examine the effects of optical excitation on the electronic structure and local atomic arrangements associated with specific impurities. Particular attention will be given to bistable impurities such as Ga or In in CdTe and other II-VI compounds as well as CdF2. Optically enhanced host (113Cd, 125Te, and 19F) nuclear spin-lattice relaxation will be used as an indicator of conversion of the bistable impurities to conventional effective mass donors. Impurity species NMR, especially 69Ga, will be used in combination with in situ illumination to search for direct evidence of structural rearrangements in the impurity ground state. Impurity species NMR (69Ga and 63Cu) will also be used to study the local environments of active centers in phosphors such as SrS(Cu,M) and ZnS(Mn, Ga). The goal is to elucidate a microscopic understanding of these impurities that will facilitate the engineering of this class of material for specific electronic and optical applications. The proposed experiments will provide a venue for Ph.D. and M.S. graduate education and undergraduate research opportunities; they will also be exploited for enrichment of undergraduate courses in Modern Physics and Solid State Physics in the form of projects and demonstrations.%%%The controlled introduction of specific impurities is critical in determining the properties of technologically important electronic and optical materials. This renewal award to a senior professor at Oregon State University is for research that will focus on a class of impurities that are optically-active. Such impurities change their atomic-scale properties when illuminated or emit light when subject to illumination or electric currents in the host material. The applications of these materials include light emitting elements for flat panel displays and optical data storage. Nuclear magnetic resonance (NMR) is a spectroscopy that reveals atomic-scale details of the environments of specific chemical elements in a material. In this research, NMR will be used to probe the effects of illumination on host atom environments, say Cd in CdTe or CdF2, or impurities such as Ga in these materials and in phosphors being developed for flat panel displays. The goal of this and related research is to reach a level of microscopic understanding that will facilitate the engineering of this class of material for specific electronic and optical applications. The proposed research will be integrated into undergraduate and graduate education. Ph.D. and thesis research will train graduates for entry into U.S. high technology industry. Undergraduates will participate in undergraduate research and through enrichment (projects and demonstrations) of formal courses in Modern Physics and Solid State Physics at Oregon State University.***