Formation and structure of vacancy defects in silicon: Combined Metropolis Monte Carlo, tight-binding molecular dynamics, and density functional theory calculations

摘要

We present the formation and structure of vacancy clusters (V_n, n≤48) in crystalline Si based on combined Metropolis Monte Carlo, tight-binding molecular dynamics, and density functional theory calculations. In this size regime, vacancy clusters are predicted to favor fourfold coordination by nullifying dangling bonds created by Si lattice-atom removal. Our results also highlight the identification of a stable high-symmetry V_(32) configuration that exhibits a complex but ordered tetrahedral core/shell shape. When n > 25, fourfold-coordinated (FC) clusters commonly show the core/shell figure while smaller FC clusters (10