Understanding the Atomic Structure and Electronic Properties of Zinc Oxide Interfaces

技术.本计画针对未掺杂与掺杂氧化锌薄膜中缺陷（位错与掺杂物）、薄膜/基板界面与p-n接面之结构、组成、化学键结与电子性质。具体任务是：（1）ZnO薄膜的生长与表征，不同类型掺杂和p-n结的ZnO薄膜的生长与表征，界面结构与电子性质的原子尺度表征，利用TEM/STEM保持器结合高分辨透射电镜（HRTEM）和电子能量损失谱（EELS）原位研究晶体缺陷和界面的稳定性及其对外加电场的响应。要研究的晶体缺陷和界面包括掺杂剂、位错、晶界、膜/衬底界面和p-n结。将利用具有球形像差校正的冷场发射枪的TEM进行这些研究;它为成像提供亚微米分辨率，并为电子能量损失谱提供能量扩展为0.3 eV的非常明亮的电子探针。将强调缺陷和界面的原子结构和纳米级电子特性的广泛表征。基于这些结果的理解有望允许随后开发p型ZnO材料，用于电子和光学器件-检测器，发光体，透明薄FET或基于自旋的器件。非技术性。该项目解决了具有技术相关性的电子/光子材料科学主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经验纳入这项研究。研究生和本科生都将参与跨学科研究目标解决方案的多个步骤。PI将通过美国宇航局的夏季高中学徒研究计划，每年夏天为密歇根大学的天才女性和少数民族K-12学生举办实践研讨会（材料的微观世界）。这种跨学科的教育将为学生提供一个独特的视角，预计将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.