<title>Quantum chemical simulation of silicon nanostructures</title>

1999

The point defects in silicon, their migration, geometry and electronic structure, as well as some models for nanowires, were studied. The ab initio Self Consistent Field Molecular Orbital method and the molecular cluster model were used. Hydrogen pseudoatoms were used to saturate dangling bonds of the cluster. The influence of the compression onto defect structure and properties was simulated by changing the bond length value. The silicon interstitial migration activation energy, calculated as the difference between the total energies of the cluster with interstitial in tetrahedral and hexagonal positions, is 4.21 eV, and it does not depend on local pressure. The influence of high pressure …

Structure of Oxygen and Silicon Interstitials in Silicon

1999

Structure and diffusion of oxygen and silicon interstitials in silicon

1999

Abstract Ab initio quantum chemical simulation of silicon interstitials and oxygen-related defects Oi, V–O2, and V–O4 in oxygen-containing silicon was performed using the embedded molecular cluster model. The defect geometry and electronic structure were studied. The migration activation energy for Oi defect was estimated as 2.73 eV at the atmospheric pressure, and 2.70, 2.68, and 1.92 eV for the lattice compressed by 0.25, 0.37, or 5.0 per cent, respectively. The activation energy of silicon interstitial is not changing with pressure. The molecular cluster used to simulate V–O4 defect with C2v symmetry was shown to have only slight deviation from D2d at atmospheric pressure, a strong devia…