physics_175_2

Physics Colloquium - March 28, 2013

Shedding light on the structural and electronic properties of SiC nanostructures

Abstract: Bulk SiC exhibits robust electrical, thermal, and mechanical properties. It possesses high strength, high thermal conductivity, stability at high temperature, high resistance to shocks, low thermal expansion, high refractive index, wide (tunable) bandgap and chemical inertness. Because of its outstanding physical properties, bulk SiC has now become one of the most promising materials for power electronics, heterogeneous catalyst supports, hard materials, and biomaterials. It is of interest, therefore, to understand how these properties would be modified in SiC nanostructures. Furthermore, bulk SiC manifests in many polymorphic forms due to different stacking arrangements of Si/C bilayers in cubic zinc-blended and the hexagonal wurtzite structures along the c-axis and the <0001> -direction, respectively. It is, therefore, natural to ask the question: “how will such polymorphism manifest itself in quasi-one and two-dimensional structures of SiC?” With this in mind, we have systematically investigated the SiC nanostructure from energetic considerations, bonding nature, stacking arrangements, etc. employing quantum mechanics based simulation approaches. In this talk, I will present and discuss our the results including (i) the sp2 bonding nature in the graphitic-like and tubular Silicon Carbides, (ii) the morphology, stability, and the electronic properties of SiC nanowires, and (iii) the formation of the bucky-diamond structure of SiC clusters.

Professor Ming Yu
Department of Physics
University of Louisville