Collaborative Research: Identifying and Controlling Conductivity Variations in Semiconductor Nanowires

1604931 / 1603904 PI：Shan，Jerry W.作者：Michael A.职务名称：合作研究：识别和控制半导体纳米线中的电导率变化半导体纳米线正在成为重要的纳米级构建块，用于能量收集、固态照明、传热、信息处理、化学检测甚至生物电子学等多种应用。这些纳米级材料在其结构和组成方面表现出显著的变化，这可能会限制其功能和特性。更好地理解和控制半导体纳米线合成中的批次间变化将使纳米线性能的精确调整能够产生电导率分布远窄于当前最先进水平的集合。该项目侧重于统计评估半导体纳米线电导率的变化，了解变化的根本原因，并开发最小化的方法，以实现商业应用。该研究项目涉及将新型高通量电取向光谱（EOS）与最先进的纳米线合成技术相结合。EOS是基于受到交流电场的液体悬浮纳米线的频率依赖性对准速率，每天可以测量约一千根纳米线的电导率，比现有的直接接触方法快数百倍。一个基本的化学纳米线生长的理解允许仔细控制的异质界面的过程，影响掺杂剂的掺入。初步数据证实，纳米线的电导率可以在一个系综内变化很大。拟议的工作将侧重于确定影响半导体纳米线电导率的关键工艺参数，以及开发减少电导率变化的新工艺。 将研究两类纳米线：（1）具有不同n和p特性的均匀掺杂的Si和Ge纳米线和（2）SiGe合金、核-壳和其他异质纳米线。 虽然Si和Ge纳米线是该项目的重点，但该方法预计将适用于广泛的其他材料（例如，III-V半导体、氧化物等）。该项目将涉及研究生的跨学科和跨大学培训，招募少数民族本科生在主要研究人员的实验室进行研究项目，课程开发活动以及旨在吸引K-12学生从事STEM职业的外联工作。

1604931 / 1603904 PIs: Shan, Jerry W. / Filler, Michael A. Title: Collaborative Research: Identifying and Controlling Conductivity Variations in Semiconductor NanowiresSemiconductor nanowires are emerging as important nanoscale building blocks for applications as diverse as energy harvesting, solid-state lighting, heat transfer, information processing, chemical detection, and even bioelectronics. These nanoscale materials exhibit significant variations in their structure and composition that can limit their function and properties. A better understanding and control of run-to-run variations in semiconductor nanowire synthesis will enable precise tuning of nanowire properties to yield ensembles with conductivity distributions far narrower than the current state-of-the-art. This project focuses on statistically assessing variations in the electrical conductivity of semiconductor nanowires, understanding the underlying causes for the variations, and developing methodologies that minimize the, in order to enable commercial applications. The research project involves coupling novel high-throughput electro-orientation spectroscopy (EOS) with state-of-the-art nanowire synthesis techniques. EOS is based on the frequency-dependent alignment rates of liquid-suspended nanowires subjected to an AC electric field and can measure the conductivity of about one thousand nanowires per day, hundreds of times faster than existing direct-contact approaches. A fundamental chemical understanding of nanowire growth allows for careful control of the hetero-interfacial processes that influence dopant incorporation. Preliminary data confirm that nanowire conductivity can vary considerably within an ensemble. The proposed work will focus on identifying the critical process parameters that affect electrical conductivity in semiconductor nanowires and on the development of new processes that reduce conductivity variations. Two classes of nanowires will be studied: (1) uniformly-doped Si and Ge nanowires of varying n and p character and (2) SiGe alloy, core-shell, and other heterogeneous nanowires. While Si and Ge nanowires are the focus of this project, the approach is expected to be applicable to a broad spectrum of other materials (e.g., III-V semiconductors, oxides, etc.). The project will involve cross-disciplinary and cross-university training of graduate students, recruiting of minority undergraduate students into pursuing research projects in the laboratories of the principal investigators, curriculum development activities, and an outreach effort aiming at engaging K-12 students into pursuing STEM careers.