Investigation of the stability and charge states of vacancy in clusters Si_29 and Si_38

Abstract

Stability and charge states of vacancy in Si_29 and Si_38 clusters have been calculated by non-conventional tight-binding method and molecular dynamics. Based on the theoretical calculations, it was shown that the vacancy in pure dimerized clusters is unstable, while in hydrogenated Si_29H_24 and Si_38H_30 clusters it is stable, but leads to a distortion of its central part with the transition of symmetry from Td to C_3v and a change in the forbidden gap. The charges of cluster atoms in the presence of a vacancy are distributed so that all silicon atoms acquire a stable negative charge, which occurs due to the outflow of electrons of the central atom to the neighboring spheres.

Keywords

• silicon nanoclusters
• charge
• vacancy
• non-conventional tight-binding method
• molecular dynamics