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

技术：该项目是在纳米尺度上研究金属与半导体纳米线和薄膜的接触。要研究的系统包括(1)金属与半导体纳米线的接触，(2)金属/复合氧化物/半导体结中先进氧化物薄膜的金属接触，以及(3)金属/有机单层/半导体结中金属与有机膜的接触。在电子器件中，接触对电荷和自旋的注入是至关重要的，但在这些新兴材料中，能带排列和微观输运过程仍然知之甚少。该项目使用弹道电子发射显微镜(BEEM)、内光电子能谱和三维静电模型，目的是对这些重要课题有一个定量的了解。该项目的重点是金属与半导体纳米线的接触。肖特基势垒与纳米线的接触都是端对上的？而更传统的方面呢？将使用BEEM研究接触几何，以确定纳米线能带与金属费米能量(即肖特基势垒高度)的对准如何取决于纳米线直径、金属功函数和纳米线周围的静电环境。非技术性：该项目解决了材料科学中具有高度技术相关性的热门领域的基础研究问题，并有望提供对半导体材料金属接触的新的科学理解，这一知识对于未来基于纳米线的电子器件的发展至关重要。该项目为研究生和本科生提供高度跨学科和协作的培训，并为仅限本科生的院校的学生和教职员工提供更多的研究机会。PI将继续积极参与课程开发，将实验室实验、小组工作和问题解决更好地整合到物理入门课程、科学推广、教师指导和旨在向中学生提供纳米技术信息和建议的推广活动中。

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.