Photoelectron Emission at Diamond-Liquid Interfaces

金刚石-液体界面处的光电子发射

• 批准号: 1207281
• 负责人: Robert Hamers
• 金额: $ 47万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1207281&HistoricalAwards=false
• 关键词: Photoelectron; Emission; Diamond; Liquid; Interfaces

TECHNICAL SUMMARYDiamond has an unusual property known as negative electron affinity (NEA) that allows it to act as a solid-state source of electrons when illuminated with ultraviolet light. The combination of diamond's NEA with its outstanding chemical stability allows it to be used as a solid-state source of electrons operating under non-vacuum conditions, even able to directly inject electrons into liquids. The proposed research supported by the Solid State and Materials Chemistry Program, will investigate the factors controlling the efficiency of electron emission into liquids such as water and tetrahydrofuran. Research efforts will focus on understanding the materials factors that control the electron emission process and identifying conditions that will increase electron emission with a broader spectrum of excitation wavelengths and on enhancing the stability of NEA. Methods to be explored include doping with phosphorus or nitrogen, and manipulation of the electrochemical double-layer at the diamond-electrolyte interface. These measurements will provide fundamental new insights into factors that control the efficiency and stability of photoelectron emission under non-vacuum conditions. This research could enable new technological applications in several fields of science and technology such as improved field-emitter displays and enable new types of chemical transformations in liquids. The project will support training and mentoring of students, including undergraduates and high school students, and efforts to engage with state legislators and other decision-makers to inform about the societal impact of scientific research. NON-TECHNICAL SUMMARYThe emission of electrons from solid materials underlies many existing technologies such as computer displays. Most materials require high temperature and high vacuum conditions in order to emit electrons and therefore cannot be used in water and other liquids. However, diamond, even when used as inexpensive thin films and/or commercial-grade diamond powder, has the unusual ability to emit electrons into liquids at room temperature when illuminated with ultraviolet light, although with relatively low efficiency. This project will explore several different approaches to improving the ability of diamond to emit electrons into liquids. If this work is successful it could lead to improved computer display technologies and to new, energy-efficienct ways to initiate important chemical reactions, including transformation of inexpensive starting materials into more useful products, such as liquid fuels. The project will support training and mentoring of students, including undergraduates and high school students, and efforts to engage with state legislators and other decision-makers to inform about the societal impact of scientific research.

技术摘要钻石具有一种称为负电子亲和力 (NEA) 的不寻常特性，使其在受到紫外线照射时可以充当固态电子源。金刚石的 NEA 与其出色的化学稳定性相结合，使其可以用作非真空条件下运行的固态电子源，甚至能够将电子直接注入液体中。拟议的研究由固态和材料化学计划支持，将研究控制电子发射到水和四氢呋喃等液体中的效率的因素。 研究工作将集中于了解控制电子发射过程的材料因素，确定通过更宽的激发波长谱增加电子发射的条件，以及增强 NEA 的稳定性。待探索的方法包括掺杂磷或氮，以及操纵金刚石-电解质界面处的电化学双层。这些测量将为非真空条件下控制光电子发射效率和稳定性的因素提供基本的新见解。这项研究可以在多个科学技术领域实现新技术应用，例如改进的场发射器显示器，并实现液体中新型化学转化。该项目将支持对学生（包括本科生和高中生）的培训和指导，并努力与州立法者和其他决策者合作，以了解科学研究的社会影响。非技术概要固体材料的电子发射是许多现有技术（例如计算机显示器）的基础。大多数材料需要高温和高真空条件才能发射电子，因此不能在水和其他液体中使用。然而，即使当用作廉价薄膜和/或商业级金刚石粉末时，金刚石也具有在紫外光照射下在室温下将电子发射到液体中的不寻常的能力，尽管效率相对较低。该项目将探索几种不同的方法来提高金刚石向液体发射电子的能力。如果这项工作成功，它可能会改进计算机显示技术，并带来新的、节能的方法来引发重要的化学反应，包括将廉价的起始材料转化为更有用的产品，例如液体燃料。该项目将支持对学生（包括本科生和高中生）的培训和指导，并努力与州立法者和其他决策者合作，以了解科学研究的社会影响。