Understanding the Atomic Structure and Electronic Properties of Zinc Oxide Interfaces

技术上的。该项目研究了未掺杂和掺杂的氧化锌薄膜中缺陷(位错和掺杂剂)、薄膜/衬底界面和p-n结的结构、成分、化学键和电子性质。具体任务是：(1)不同类型掺杂和p-n结的氧化锌薄膜的生长和表征；(2)界面结构和电子性质的原子尺度表征；(3)使用扫描隧道显微镜/透射电子显微镜结合高分辨透射电子显微镜和电子发射光谱技术，原位研究晶体缺陷和界面对外加电场的稳定性和响应。需要研究的晶体缺陷和界面包括掺杂、位错、晶界、薄膜/衬底界面和p-n结。具有球差校正的冷场发射枪的透射电子显微镜将用于这些研究；它将为成像提供亚分辨率，并为电子能量损失谱提供一个能量分布为0.3 eV的非常明亮的电子探针。重点是对缺陷和界面的原子结构和纳米级电子性质的广泛表征。基于这些结果的理解有望为后续开发p型氧化锌材料提供支持，这些材料适用于电子和光学设备--探测器、光发射器、透明薄膜FET或自旋基设备。非技术性。该项目涉及具有技术相关性的电子/光子材料科学专题领域的基础研究问题。该项目包括为学生提供多方面的教育机会。本科生将通过高级论文和REU经验被纳入到这项研究中。研究生和本科生都将参与解决跨学科研究目标的多个步骤。PI将通过NASA的暑期高中学徒研究计划，每年夏天在密歇根大学为有天赋的女性和K-12少数族裔学生举办动手研讨会(微观材料世界)。这种跨学科的教育将为学生提供一个独特的视角，有助于促进他们对工业和学术研究的兴趣。

Technical. This project addresses structure, composition, chemical bonding, and electronic properties of defects (dislocations and dopants), film/substrate interfaces, and p-n junctions in un-doped and doped ZnO films. Specific tasks are: (1) growth and characterization of ZnO thin films with different types of dopants and p-n junctions; (2) atomic-scale characterization of structure and electronic properties of interfaces; (3) in situ study of the stability and response of crystal defects and interfaces to applied electric field using an STM/TEM holder for TEM/STEM in combination with HRTEM and EELS. The crystal defects and interfaces to be studied include dopants, dislocations, grain boundaries, film/substrate interfaces, and p-n junctions. A TEM with spherical aberration-corrected cold field emission gun will be utilized for these studies; it provides sub-Å resolution for imaging and a very bright electron probe with an energy spread of 0.3 eV for electron energy-loss spectroscopy. Extensive characterization of the atomic structure and nanoscale electronic properties of defects and interfaces will be emphasized. Understanding based on these results is expected to allow subsequent development of p-type ZnO material, desirable for electronic and optical devices--detectors, light-emitters, transparent thin FETs or spin-based devices. Non-Technical. The project addresses fundamental research issues in a topical area of electronic/photonic materials science having technological relevance. The project includes multifac-eted educational opportunities for students. Undergraduates will be incorporated into this re-search via senior theses and REU experiences. Both graduate and undergraduate students will become involved in multiple steps of the solution of interdisciplinary research objectives. The PI will run hands-on workshops (Microscopic World of Materials) each summer for gifted female and minority K-12 students at the University of Michigan through NASA's Summer High School Apprenticeship Research Program. This interdisciplinary education will provide students with a unique perspective expected to be helpful toward furthering their interest in industry and academic research.