Hydrogen in Crystalline Semiconductors

技术：该实验研究计划的目标是对电子技术中重要的半导体基质材料中的氢杂质及其性质有一个基本的了解。 轻氢原子的振动光谱已被证明是含氢缺陷的微观结构和性质的强有力的探针，并且是本项目中使用的主要方法。 最近的进展使得以下实验具有吸引力：（i）已经发现氢增加稀III-N-V合金的带隙。 振动光谱提供了有关导致这种效应的缺陷的结构以及它们所含氢原子数量的信息。 (ii)氢在硅中形成间隙分子，其旋转振动特性最近被破译。 红外光谱用于探测间隙氢分子的邻-对位跃迁。 (iii)已经发现H对半导体氧化物如ZnO的导电性具有强烈的影响。 利用低温氢离子注入ZnO的振动光谱研究了ZnO中孤立氢缺陷的性质。 研究生和本科生进行半导体中杂质的实验，这是本研究计划的重点。 学生学习半导体的物理学，材料的光学特性和晶体缺陷。 非技术性：了解半导体中的氢杂质对电子技术至关重要。 氢很容易被有意或无意地引入半导体。 氢一旦存在，就会改变半导体材料的电学性质和电子器件的性能。 实验研究的微观结构和基本性质的缺陷“分子”在半导体中含有氢是这个研究计划的重点。 感兴趣的半导体材料包括对集成电路和太阳能电池重要的Si，以及对发光器件重要的化合物半导体。 我们将研究扩展到半导体技术的相关领域。 例如，已经开发了一种通过工业上用于提高太阳能电池效率的方法来检测引入到Si中的低浓度氢的方法，并用于研究制造工艺。 这个半导体中氢的研究计划为本科生和研究生提供了一个很好的机会，可以为影响电子技术的物理问题做出重要贡献，通常与美国和国外的领先科学家合作。

Technical:The goal of this experimental research program is a fundamental understanding of the hydrogen impurity and its properties in semiconductor host materials that are important in electronics technology. Vibrational spectroscopy of the light hydrogen atom has proved to be a powerful probe of the microscopic structure and properties of hydrogen-containing defects and is the principal method used in this project. Recent advances make the following experiments attractive: (i) Hydrogen has been found to increase the band gap of dilute III-N-V alloys. Vibrational spectroscopy provides information about the structures of the defects causing this effect and the number of hydrogen atoms they contain. (ii) Hydrogen forms interstitial molecules in Si whose rotational-vibrational properties have recently been deciphered. Infrared spectroscopy is used to probe the ortho-para transition of the interstitial hydrogen molecule. (iii) H has been found to have a strong effect on the conductivity of semiconducting oxides like ZnO. Vibrational spectroscopy of H implanted into ZnO at cryogenic temperature investigates the properties of the fundamental isolated hydrogen defect. Graduate and undergraduate students conduct the experiments on impurities in semiconductors that are the focus of this research program. Students learn about the physics of semiconductors, the optical properties of materials, and crystal defects. This experience provides an excellent foundation for careers in science and engineering.Non-technical:An understanding of the hydrogen impurity in semiconductors is vital in electronics technology. Hydrogen is introduced easily into semiconductors, either intentionally or unintentionally. Once present, hydrogen modifies the electrical properties of semiconductor materials and the behavior of electronic devices. Experimental studies of the microscopic structures and fundamental properties of defect "molecules" in semiconductors that contain hydrogen are the focus of this research program. The semiconductor materials that are of interest include Si, which is important for integrated circuits and solar cells, and compound semiconductors, which are important for light-emitting devices. We extend our research to relevant areas of semiconductor technology. For example, a method to detect the small concentration of hydrogen introduced into Si by methods used by industry to improve the efficiencies of solar cells has been developed and used to study manufacturing processes. This research program on hydrogen in semiconductors provides an excellent opportunity for undergraduate and graduate students to make important contributions to problems in physics that have an impact on electronics technology, often in collaboration with leading scientists in the U.S. and abroad.