Studying novel materials using synchrotron-based spectroscopy and density functional calculations

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The outer and less strongly bound electrons of matter are responsible for most material properties including color, chemical bonding, atomic and electronic structure, magnetism, band gap, electrical and heat conductivity, and even super-conductivity. Having the means to measure, model, and understand the outer electrons of a material is the key to understanding and tailoring important physical properties. This research will employ synchrotron-based soft X-ray spectroscopy at the group's own endstation at the Canadian Light Source to answer key questions concerning the structure of new materials in three areas of focus: 1. The role of vacancies in spinelectronic and other materials for new storage devices and high performance computing: Vacancies are important in condensed matter physics but notoriously difficult to detect. We have pioneered a method that allows studying vacancies. We specifically study their role in new ferromagnetic semiconductors for applications that use the electron spin and charge to store information. If realized on a large scale, spintronics will revolutionize computing capabilities by allowing faster processing speed, higher storage density and less energy consumption. 2. New materials for LED lighting applications: We focus on the detailed characterization and development of the electronic structures of a series of next-generation, rare earth-doped, nitride phosphors. These narrow-band-emitting, high-efficiency phosphors have demonstrated outstanding potential for use in phosphor-converted light emitting diodes (pc-LEDs), a technology poised to replace traditional incandescent lights. They are expected to lead to an outstanding reduction of 15% in global energy consumption with substantially greater long-term reductions. This reduction in energy consumption will be driven by the development of new high-efficiency phosphors. 3. Low dimensional materials: The first goal of this project is to elucidate basic physical and electronic properties of one dimensional, linear carbon chains, as well as how the choice of substrate, carbon chain length and introduction of dopants affects the electronic properties. In the extension to two-dimensional materials, we will study single layered materials phosphorene and borophene in an attempt to establish freestanding monolayers that have unique properties in terms of strength and charge mobility that are of fundamental interest and applicable in many areas. Overall, the comparison of our synchrotron measurements with our state-of-the-art theoretical calculations will provide very detailed insight and facilitate the design of new materials with tailored electronic, optical, magnetic, and chemical properties for use in lighting applications with much less energy consumption and electronics applications for faster and more energy efficient computing allowing handling of larger data sets.