Nanometer-Scale Studies of Contacts to Nanowires, Advanced Oxide Films, and Molecular Layers

技术：该项目旨在研究纳米尺度下金属与半导体纳米线和薄膜的接触。待研究的系统包括（1）半导体纳米线的金属接触，（2）金属/复合氧化物/半导体结中的高级氧化物膜的金属接触，以及（3）金属/有机单层/半导体结中的有机膜的金属接触。接触对于电子器件中电荷和自旋的注入至关重要，但在这些新兴材料中，人们对能带排列和微观输运过程仍然知之甚少。弹道电子发射显微镜（BEEM），内部光电子能谱和三维静电建模在这个项目中使用，旨在获得这些重要的主题的定量了解。该项目的重点是半导体纳米线的金属接触。肖特基势垒接触纳米线在这两个？端对端和更传统的？侧？将使用BEEM研究接触几何形状，以便确定纳米线能带如何对准金属费米能（即，肖特基势垒高度）取决于纳米线直径、金属功函数以及纳米线周围的静电环境。该项目解决了具有高技术相关性的材料科学专题领域的基础研究问题，预计将为半导体材料的金属接触提供新的科学认识，这是开发未来基于MEMS的电子设备所迫切需要的知识。该项目为研究生和本科生提供了高度跨学科和协作的培训，并为学生和来自本科院校的教师提供了更好的研究机会。PI将继续积极参与课程开发，以更好地将实验室实验，小组工作和解决问题纳入物理学入门课程，科学推广，教师指导和旨在向中学生提供有关纳米技术的信息和建议的推广活动。

Technical: This project is to study metal contacts to semiconductor nanowires and thin films at the nanometer scale. The systems to be investigated include (1) metal contacts to semiconductor nanowires, (2) metal contacts to advanced oxide films in metal/complex oxide/semiconductor junctions, and (3) metal contacts to organic films in metal/organic-monolayer/semiconductor junctions. Contacts are critical for injection of charge and spin in electronic devices, but in these emerging materials the energy band alignments and microscopic transport process are still poorly understood. Ballistic electron emission microscopy (BEEM), internal photoemission spectroscopy, and three-dimensional electrostatic modeling are used in this project, aiming to obtain a quantitative understanding of these important topics. The emphasis of the project is on metal contacts to semiconductor nanowires. Schottky barrier contacts to nanowires in both the ?end-on? and the more conventional ?side? contact geometries will be studied using BEEM, in order to determine how the nanowire energy band alignment to the metal Fermi energy (i.e., the Schottky barrier height) depends on the nanowire diameter, on the metal work function, and on the electrostatic environment around the nanowires.Non-technical: The project addresses basic research issues in a topical area of materials science with high technological relevance, and is expected to provide new scientific understanding of metal contacts to semiconductor materials, a knowledge that is critically needed for the development of nanowire-based electronic devices of the future. This project provides highly interdisciplinary and collaborative training for graduate and undergraduate students and enhanced research opportunities for students and a faculty member from an undergraduate-only institution. The PI will continue active involvement with curriculum development to better integrate laboratory experiments, group work and problem solving into introductory physics courses, science outreach, teacher mentoring, and outreach activities aimed at providing information and advise about nanotechnology to middle school students.