Density-functional theory calculations on H defects in Si

Abstract

We use first principles calculations and elasticity theory to study hydrogen aggregation in silicon. We discuss possible structures of small hydrogen complexes containing 4–12 H atoms and demonstrate that the lowest-energy structure is the hydrogenated glide dislocation loop. We employ elasticity theory of dislocation interaction to show that the dislocation loop is likely to grow in one dimension forming the dislocation dipole. Extending the study to larger numbers of H, we show that the hydrogenated glide dislocation dipole is favoured for H aggregates infinite in one dimension. We discuss the route for its expansion leading to the formation of two-dimensional H aggregates or platelets.