Abstract
We present the formation and structure of vacancy clusters (Vn,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 V32 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<n<25) exhibit the trace of the high-symmetry V12 structure that exhibits four identical voidlike structural units surrounding a tetragonal core. In addition, our study reveals that the formation of thermodynamically favored FC clusters can be kinetically facile.
Original language | English |
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Article number | 245209 |
Journal | Physical Review B - Condensed Matter and Materials Physics |
Volume | 80 |
Issue number | 24 |
DOIs | |
State | Published - 14 Dec 2009 |