Laser joining and assembly of nanowires: processing, structure, properties and performance

这项研究计划将研究激光连接和组装纳米线的基础和工程问题，结合实验和数值模拟方法。我们的目标是，基于我们以前的工作激光连接的纳米粒子和纳米线，建立激光和其他工艺参数之间的基本关系，冶金特性的半导体纳米线和金属电极/基板，界面结构，和电接触特性和性能的不同接头的选择纳米线为基础的电子元件和设备。* 有三个具体目标，即：(1)研究了纳米线激光连接过程中工艺参数与接头形成的关系，（2）研究激光加工参数对界面结构的影响，包括界面处的晶体取向关系和电接触特性;以及（3）构建基于纳米线的电子器件原型，并探索其与界面结构和电接触性质相关的电性能，以及研究金属-半导体界面处的载流子输运机制。* 该计划将涵盖氧化物半导体纳米线，如TiO 2，ZnO和CuO，以及金属电极，如Au，Ag和Ti。初始处理参数将包括激光能量密度、脉冲持续时间、光斑尺寸等。先进的分析设备，如透射电子显微镜和X射线光电子发射显微镜，将用于详细研究界面处的冶金缺陷和晶体取向关系，欧姆接触的接触电阻和肖特基接触的能量势垒高度等电性能将被研究为界面结构将研究功能原型组件和器件（如场效应晶体管和忆阻器）的电气性能。数值模拟的实例包括热历史的有限元分析和界面结构的分子动力学模拟。* 该计划的成功执行不仅将提供有价值的基本见解，如激光-纳米线相互作用，而且还将开发纳米器件激光精密组装的专有技术。该计划还将培养13名高素质人才（HQP），其中包括6名博士和硕士生，4名本科工读生和3名博士后研究员，他们在材料科学与工程，激光加工和纳米器件开发领域具有尖端知识和技能。加拿大未来的竞争力也将通过他们未来在加拿大学术界、工业界和研究机构的地位得到加强。

This proposed research program will study both fundamental and engineering issues in laser joining and assembly of nanowires, with combined experimental and numerical modeling methods. The goal is to, based on our previous work on laser joining of nanoparticles and nanowires, establish fundamental relationships between laser and other processing parameters, metallurgical characteristics of dissimilar joints of semiconductor nanowires and metal electrodes/substrates, interfacial structure, and electrical contact properties and performance of selected nanowire based electronic components and devices. *** There are three specific objectives, i.e., (1) to study relationships between processing parameters and joint formation in laser joining of nanowires, based on quantitative (or semi-quantitative) thermal history at interfacial regions; (2) to investigate the effect of laser processing parameters on interfacial structures, including crystallographic orientation relations at the interface, and electrical contact properties; and (3) to build prototype nanowire based electronic devices and explore their electrical performance as related to interfacial structure and electrical contact properties, and study the carrier transport mechanisms at the metal-semiconductor interfaces. *** The program will cover oxide semiconductor nanowires, such as TiO2, ZnO and CuO, and metal electrodes such as Au, Ag and Ti. Initial processing parameters will include laser fluences, pulse duration, spot size, etc. Advanced analytical equipment such as transmission electron microscopy and X-ray photoelectron emission microscopy will be used for detailed study of metallurgical defects and crystal orientation relations at interfaces, etc. Electrical properties such as contact resistance of Ohmic contacts and energy barrier height of Schottky contacts will be studied as functions of interfacial structures. Electrical performance of functional prototype components and devices such as field effect transistor and memristor will be investigated. The examples of numerical modeling include finite element analysis of thermal history and molecular dynamic simulation of interfacial structures. *** The successful execution of this program will not only provide valuable fundamental insights such as laser-nanowire interactions, but also develop know-how technologies in laser precision assembly of nanoscale devices. This program will also train 13 highly qualified personnel (HQP), including six doctoral and master's students, four undergraduate work-term students and three post-doctoral fellows with cutting edge knowledge and skills in the fields of materials science and engineering, laser processing and nanoscale device development. Canada's future competitiveness will also be enhanced through their future positions in Canadian academia, industries and research institutes.