探索半导体纳米线的奇特物理性质及可能应用

探索半导体纳米线的奇特物理性质及可能应用

报告人：俞大鹏教授

俞大鹏，男，1959年3月生。1993

年在法国南巴黎大学固体物理实验室

（Orsay）获博士学位。2000年获得

国家杰出青年科学基金，2002年获得

教育部长江学者特聘教授，是教育部长

江学者与创新计划“新型低维功能结构

与物理” 创新团队学术带头人。俞大鹏

教授的主要研究方向为准一维半导体纳

米结构与物理性质研究，是国际纳米线研究的创始人之一，在纳米线的制备、物理性质和器件效应研究方面做出的主要学术贡献包括: 发展了催化诱导与气相输运新方法、新技术规模制备硅纳米线，基本解决自下而上可控制备纳米线的核心难题；开拓了氧化物纳米线材料新领域；深入、系统地研究了纳米线的奇特物理性质和应用基础。俞大鹏教授共在国际核心专业刊物上发表360多篇论文，含国际顶级专业刊物论文Physical Review B/Letters（14）、 Applied Physics Letters/JAP（75）、Advanced Materials（11）、Nano Letters（7）等160余篇。相关论文被国内外其他同行累计引用超过10000次，H因子为54。以第一完成人获得了2004年度教育部提名自然科学一等奖、2007年获国家自然科学二等奖。担任Nano Research、《科学通讯》等国内外学术刊物编委，被邀请担任美国物理研究所（AIP）10 Year Review Committee Member （全球6名科学家）。

Exploring the Peculiar Physical Properties and Possible Applications of Semiconductor Nanowires

YU Dapeng

Nanowires have been a top-five focused research topics in physics, and stimulated intensive interests world-wide. This lecture composes of two major parts.

Figure 1: (a). Mass-production of silicon nanowires from the bottom; (b). Strain modulation of the emission energy and electronic structures of semiconductor nanowires; (c). High field emission current density destined for planar display; (d). Flexible nanowire solar cells.

In the first part, I will give a brief summary of our pioneer and leading contributions to the world-wide nanowire research. (1). We are the pioneers to synthesize silicon nanowires from the bottom via a catalytic-directed growth of semiconductor nanowires, and enable the controllability in size, orientation, and superlattice/coreshell heterostructures of semiconductor nanowires. (2). We extended the concept of nanowire synthesis to a wide variety of metal oxide nanowires, leading to a world-wide following up of the breakthrough. (3). It is further demonstrated that the physical properties of the semiconductor nanowires can be modified/ via chemical doping, tuned by magnetic and strain fields, resulting in the nanowire p-n heterojunctions, diluted magnetic semiconductors, and strain sensors. (4).We are the first to provide the experimental evidence of quantum confinement effect in silicon nanowires. It is showed that the spin current of a single magnetite nanowire can be tuned via magnetic field (spin filter), and the thermal spin transfer torque effect was

also evidenced in a nanowire spin-valve. (5). We are the few pioneers to explore the field emission properties of nanowire arrays, thanks to the sharp tiny tips of the nanowires showing abnormal large field enhancement factor. The possible applications of the nanowire networks in high efficiency flexible solar cells are also demonstrated. Above pioneer work has lead to a total reference/citations >10,000 times by colleagues world-wide, and an H index of 54.

In the main second part, I will extend to show the advantage of both high spatial and energy resolution cathodoluminescence (CL) in characterization of the fine structures of the nanomaterials. In particularly, I will demonstrate that the high special resolution of the CL at ~ 5.5 K enable us to address the significant strain modulation of the optical emission and electronic structures of semiconductor nano/micro wires. In contrast, the high energy resolution of the CL makes it possible to “see” directly the resonant SPP modes that are confined to the metal nanocavity.