Architectures and profiling of nanomaterials with ion beams

由于受限粒子中的量子效应，物质的基本性质发生了巨大的变化。这是纳米科学的基础，也是生产先进材料和设备的基石。对这些改进材料和器件的追求在很大程度上依赖于现有的和新的方法，在原子尺度上改变它们的结构、组成和关键特性。在我们的小组中，我们专注于深入了解复杂材料及其界面的原子尺度行为。我们采用离子束注入和分子束外延（MBE）等先进的纳米材料生长方法。我们依靠亚纳米深度分辨率（如介质能量离子散射，MEIS）和原子横向分辨率的表面和界面表征来建立我们对表面和界面过程的基本理解。我们使用这些知识作为理解设备性能的基础。提出的研究计划可分为两个相互关联的主题：***主题1：宽波长光学器件的量子半导体结构。我们将探索在各种介电材料（氧化物，氮化物和碳化物）中离子注入Si和Ge制成的半导体量子点（QDs）。主要目的是探索这些体系的基本物理性质，如量子点的成核和生长，以及使用各种光谱工具的载流子的辐射和非辐射重组。特别的努力将给予界面的理论建模，界面上的缺陷形成，以及使用已建立的和新的模型对输运性质的描述。了解这些问题，并将结果与光致发光产率和电荷输运等光学和电学性质相关联，将大大提高对发光器件的基本理解。我们的团队已经取得了变革性的突破，使用MBE生长水平外延硅线，用于增强光转换和宽带太阳能电池。我们将集成我们的Si/Ge线作为高效光电活性材料。主题2：高分辨率离子深度剖面。目标是开发离子束分析的新方法，并对超薄薄膜和纳米颗粒进行高分辨率分析，重点关注界面，并开发光子学和锂电池材料的界面结构的综合模型。离子束方法将与x射线光发射、吸收近边结构和中子深度剖面协同应用，以检查金属和其他系统中被动氧化物的扩散机制，包括原位研究。***我的研究项目提供了在加拿大独一无二的离子束分析研究。我将在一个仪器密集和跨学科的研究环境中培养未来的科学家在技术重要领域。

The fundamental properties of matter change dramatically due to quantum effects in confined particles. This is the foundation of nanoscience and a cornerstone for the production of advanced materials and devices. The pursuit of these improved materials and devices strongly depends on existing and new methods of changing their architecture, composition and key properties at the atomic scale. In our group we focus on gaining insights into the atomic-scale behavior of complex materials and their interfaces. We employ advanced methods of nanomaterials growth, such as ion beam implantation and molecular beam epitaxy (MBE). We rely on surface and interface characterization with sub-nanometer depth resolution (such as medium energy ion scattering, MEIS), and the atomic lateral resolution to build our fundamental understanding of processes at the surfaces and interface. We use this knowledge as a foundation for understanding device performance. The proposed research program may be divided into two interconnected themes:***Theme 1: Quantum semiconductor structures for broad-range wavelength optical devices. We will explore semiconductor quantum dots (QDs) made of ion-implanted Si and Ge in various dielectric materials (oxides, nitrides and carbides). The key objective is to explore the basic physical properties of these systems, such as the nucleation and growth of QDs, and radiative and non-radiative recombination of carriers using various spectroscopic tools. Special effort will be given to the theoretical modelling of interfaces, defect formation at the interfaces, and the description of the transport properties using established and new models. Understanding these issues and correlating the results to optical and electrical properties such as the photoluminescent yield and charge transport will greatly improve the basic understanding of light-emitting devices. Our group has had a transformative breakthrough growing horizontal epitaxial Si wires using MBE for enhanced photoconversion and broad-band solar cells. We will integrate our Si/Ge wires as efficient optoelectronic active materials.***Theme 2: High resolution ion depth profiling. The objectives are to develop new methods of ion beam analysis, and to perform high-resolution profiling of ultra-thin films and nanoparticles with a focus on the interfaces and to develop a comprehensive model of interface structures for photonics and lithium battery materials. Ion beam methods will be applied in synergy with x-ray photoemission, absorption near edge structure and neutron depth profiling to examine the mechanism of diffusion in passive oxides on metals, and other systems, including in situ studies.***My research program offers research in ion beam analysis that is unique in Canada. I will train future scientists in an instrument-intense and interdisciplinary research environment in technologically-significant areas.