Architectures and profiling of nanomaterials with ion beams

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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.