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，其作为智能电子、光子、光电、热电和光伏系统的构建块引起了人们的极大兴趣。为了利用这些潜力，人们已经做出了广泛的努力来理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。通过控制稳定同位素的相对比例和空间分布，可以显著影响体半导体的几种物理性质。探索纳米线和纳米膜中的这些同位素效应为突出微妙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，它有三个稳定的同位素28 Si，29 Si和30 Si。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传输;以及（ii）研究金属催化的外延纳米线中的质量传输和原子混合。我们希望从这项首次研究中获得的信息对于半导体的重要领域来说是非常有价值的，通过创建一个独特的平台来探索重要的尺寸相关特性的起源并设计各种新颖的器件。特别是，这项研究将提供深入了解纳米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。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知识具有非常重要的意义。高素质人才的培训是我们的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，纳米纤维和先进的纳米表征技术的深入了解。这为他们提供了更大的责任感，创造力和自我指导的出口，并为他们在加拿大大学，国家实验室和行业的研发职业做好了充分的准备。

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.