Free energy molecular dynamics simulations of pulsed-laser-irradiated Si O2: Si-Si bond formation in a matrix of Si O2

Abstract

Recent experiments have shown that pure Si structures in a matrix of Si O2 can be formed by electron excitation techniques, with appealing applications in nanotechnology. Our ab initio simulations provide an insight into the underlying mechanism, showing that electron excitations weaken Si-O bonds in Si O2, dislodge O atoms and allow Si dangling bonds to reconstruct in stable Si-Si structures below the melting temperature. Differences in diffusivity of O (fast) and Si (slow) are shown to play a decisive role in the process. © 2005 American Institute of Physics.