Hydrogen in Zinc Oxide and Related Materials

技术：提出的工作将实验研究氧化锌（ZnO）半导体，作为光电应用的材料再次引起人们的兴趣。虽然ZnO具有许多固有的优点，但缺乏对掺杂物和缺陷的控制是实现实用化器件的障碍。广泛应用所必需的可靠的p型电导率一直难以捉摸。一个关键的挑战是在引入受体的同时又不被补偿供体搞得不知所措。氢在ZnO的受体掺杂和无意的n型电导率中起着核心作用。提出的工作将集中在氧化锌和相关材料中不同形式的氢。具体来说，间隙给氢体、取代给氢体、受体-氢配合物和空位-氢配合物将通过一系列实验技术进行研究。在这个更新提案中，研究将从ZnO扩展到其他氧化物晶体，包括氧化锡和钛酸锶。提出的工作将阐明透明导电氧化物中n型导电性的起源，这是一个具有技术后果的开放问题。该项目的总体目标是研究氢在ZnO和其他氧化物晶体中的行为。研究目标将促进对半导体中氢的基本理解。通过将研究扩展到氧化物晶体，PI将研究在不同材料系统中普遍行为的可能性。最“高风险”的目标是实现p型ZnO。ZnO中可靠的p型导电性将是变革性的，开辟了一系列新的应用。这个更新项目建立在PI研究小组的重要工作基础上，这些工作产生了高影响力的出版物、受邀演讲、博士论文和本科生研究经历。非技术：该项目涉及与技术相关的材料科学专题领域的基础研究问题，并有望为跨学科领域的研究生和本科生培训提供独特的机会。预期这一研究项目还将通过培训这一研究领域的科学家，通过出版物广泛传播这一研究结果，产生更广泛的影响。拟议的教育活动也将使从小学到博士的一系列学生受益。结合本提案的研究部分，教育和推广活动将鼓励来自不同背景的学生进入与材料科学和固态物理相关的领域。

Technical: The proposed work will experimentally study Zinc oxide (ZnO) semiconductor that has attracted resurgent interest as a material for optoelectronic applications. While ZnO has many inherent advantages, the lack of control over dopants and defects presents an obstacle to the realization of practical devices. Reliable p-type conductivity, necessary for widespread applications, has been elusive. A key challenge is to introduce acceptors without being overwhelmed by compensating donors. Hydrogen plays a central role in acceptor doping of ZnO as well as unintentional n-type conductivity. The proposed work will focus on different forms of hydrogen in ZnO and related materials. Specifically, interstitial hydrogen donors, substitutional hydrogen donors, acceptor-hydrogen complexes, and vacancy-hydrogen complexes will be investigated with a range of experimental techniques. In this renewal proposal, research will be extended from ZnO to other oxide crystals, including tin oxide and strontium titanate. The proposed work will shed light on the origins of n-type conductivity in transparent conducting oxides, an open question with technological ramifications. The overall goal of the project is to investigate the behavior of hydrogen in ZnO and other oxide crystals. The research goals will promote a fundamental understanding of hydrogen in semiconductors. By extending the research to oxide crystals, the PI will investigate the possibility of universal behavior across different materials systems. The most "high-risk" goal is the achievement of p-type ZnO. Reliable p-type conductivity in ZnO would be transformative, opening up a range of novel applications. This renewal project builds on significant work by the PI's research group that resulted in high-impact publications, invited talks, Ph.D. dissertations, and undergraduate research experiences. Non-technical: The project addresses basic research issues in a topical area of materials science with technological relevance, and is expected to provide unique opportunities for graduate and undergraduate training in an interdisciplinary field. This research project is also expected to have broader impacts through the training of scientists in this research field, through the wide dissemination of the findings of this research through publications. The proposed educational activities will also benefit a range of students from elementary to Ph.D. In conjunction with the research part of this proposal, educational and outreach activities will encourage students from diverse backgrounds to enter fields related to materials science and solid-state physics.