Structural properties of SiC zinc-blende and wurtzite nanostructures: Atomistic tight-binding theory

The electronic structures of SiC nanostructures consisting of nanocrystals and nanorods are theoretically investigated by atomistic tight-binding model including sp(3)s orbitals, spin-orbit coupling and the first-nearest neighboring interaction. The excitonic energies and states are numerically computed by the configuration interaction (Cl) description of the coulomb and exchange effect. Based on this atomistic model, single-particle gaps, excitonic gaps, coulomb energies and exchange energies of SiC nanocrystals and nanorods are analyzed as a function of diameters and aspect ratios, respectively. The comparison of the results obtained from different structures (zinc-blende and wurtzite) is theoretically reported with the aim to address the importance of the geometric structures on these detailed computations. The simulation emphasizes that the calculations of the electronic structures are mainly sensitive with the shapes, dimensions and geometric structures. The numerical results summarize that the efficient manipulation of structural properties for SiC nanostructures is theoretically accomplished by changing shapes, sizes and geometric structures. Ultimately, the atomistic information of shapes, sizes and structures in the structural properties of SiC nanostructures will be considerably implemented to SiC-based applications. (C) 2015 Elsevier Ltd. All rights reserved.