Isotopically Controlled Semiconductor Nanowires and Nanomembranes

半导体纳米线和纳米膜是多用途的纳米材料，作为智能电子、光子、光电、热电和光伏系统的基石，引起了人们的极大兴趣。为了开发这些潜力，人们已经投入了大量的努力来了解和操纵它们的物理和化学性质。在这里，我们建议引入额外的复杂性来研究这些纳米级半导体系统，并通过使用富集的稳定同位素来控制它们的一些基本性质。控制块状半导体稳定同位素的相对比例和空间分布可以显著影响块状半导体的几种物理性质。在纳米线和纳米膜中探索这些同位素效应，为强调细微但重要的现象和原子过程创造了大量机会。在这项研究中，我们将主要关注硅，它有三种稳定的同位素28Si， 29Si和30Si。我们的目标是：(i)探测和控制硅纳米线和纳米膜中的声子和热输运；（二）研究金属催化外延纳米线的质量输运和原子混合。我们期望从这一首创的研究中获得的信息通过创建一个独特的平台来探索重要尺寸相关特性的起源和设计各种新型器件，对半导体的重要领域具有极其重要的价值。特别是，这项研究将为纳米级界面原子混合的物理机制以及纳米材料中的声子性质和热导提供见解。这些方面对于理解新兴的基于纳米线和纳米膜的纳米技术的基础是非常重要的。培养高素质的人才是我们研究计划的一个组成部分，因为参与这项研究的学生将获得外延生长，纳米制造和先进纳米级表征技术的深入知识。这为他们提供了更大的责任、创造力和自我指导的渠道，并为他们在加拿大大学、国家实验室和行业的研发事业做好了完美的准备。

Semiconductor nanowires and nanomembranes are versatile nanomaterials, which have sparked a surge of interest as building blocks for intelligent electronic, photonic, optoelectronic, thermoelectric, and photovoltaic systems. To exploit these potentialities, extensive efforts have been deployed to understand and manipulate their physical and chemical properties. Here, we propose to introduce an additional complexity to study these nanoscale semiconductor systems and to control some of their basic properties by using enriched stable isotopes. Several physical properties of bulk semiconductors can be significantly influenced by controlling the relative proportions and spatial distributions of their stable isotopes. Exploring these isotope effects in nanowires and nanomembranes creates a wealth of opportunities to highlight subtle but important phenomena and atomic processes. In this research, we will primarily focus on silicon, which has three stable isotopes 28Si, 29Si, and 30Si. Our objectives are: (i) to probe and control phonon and heat transport in silicon nanowires and nanomembranes; and (ii) to investigate mass transport and atomic mixing in metal-catalyzed epitaxial nanowires. We expect the information obtained from this first-of-a-kind research to be extremely valuable for the important fields of semiconductors by creating a unique platform to explore the origin of important size-related properties and design a variety of novel devices. Particularly, this research will provide insights into the physical mechanisms of atomic mixing at nanoscale interfaces as well as into phonon properties and thermal conductance in nanomaterials. These aspects are of compelling importance to understand the basics of the emerging nanowire- and nanomembrane-based nanotechnologies. Training of highly qualified personnel is an integral part of our research program as students involved in this research will acquire an in-depth knowledge of epitaxial growth, nanofabrication, and advanced nanoscale characterization techniques. This provides them with outlets for greater responsibility, creativity, and self-direction and prepares them perfectly for R&D careers in Canadian universities, national laboratories, and industries.