Towards a Fundamental Understanding of Hot-Carrier Transport across Materials Interfaces

技术描述：本研究的目的是发展对载流子跨材料界面传输的基本理解。不同材料之间的整流接口，如p-n结和金属-半导体触点，是现代数字逻辑和光电器件的基础。本研究提供了载流子衰减、平行动量守恒和界面带结构如何影响载流子输运的知识。科学目标是：i)测量界面带结构和平行动量守恒对载流子衰减的影响，ii)用纳米级分辨率局部绘制这些效应，以及iii)开发增强或抑制这些效应的定制材料界面。该技术方法包括在最先进的超高真空室中沉积薄膜，以及使用低温原位弹道电子发射显微镜测量载流子输运。非技术描述：该项目涉及具有高技术相关性的材料界面上载流子传输的基本领域。热载流子衰减、平行动量守恒和界面带结构是固体逻辑和光电子器件中载流子输运的基本方面。这些知识的进步使功能和效率的改进成为迫切需要的，以跟上对电子设备不断增长的需求。此外，还包括一个重要的外展和教育项目，为高中生提供研究经验，以及参与社区和K-12外展活动。此外，强化培训和发展研究生和本科生，包括来自代表性不足群体的学生，是该项目的重要组成部分。

Technical Description: The objective of this research is to develop a fundamental understanding of carrier transport across materials interfaces. Rectifying interfaces between different materials such as p-n junctions and metal-semiconductor contacts are the foundation of modern digital logic and optoelectronic devices. This research provides knowledge of how carrier attenuation, parallel momentum conservation, and interface band structure affect carrier transport. The scientific objectives are to: i) measure the effects of interface band structure and parallel momentum conservation upon carrier attenuation, ii) locally map these effects with nanoscale resolution, and iii) develop custom materials interfaces which enhance or suppress these effects. The technical approach consists of thin film deposition in a state-of-the-art ultrahigh vacuum chamber, and carrier transport measurements using low-temperature in-situ ballistic electron emission microscopy.Non-technical Description: The project addresses fundamental areas of charge carrier transport across materials interfaces that have high technological relevance. Hot-carrier attenuation, conservation of parallel momentum, and interface band structure are fundamental aspects of carrier transport in solid state logic and optoelectronic devices. Advancements in this knowledge enable improvements in functionality and efficiency that are critically needed to keep pace with the ever increasing demands placed upon electronic devices. In addition, a significant program in outreach and education is included that enables research experience for high-school students, as well as the participation in community and K-12 outreach events. Furthermore intensive training and development of graduate and undergraduate students, including those from underrepresented groups, is a significant part of the project.