Interaction of vacancies with partial dislocations in silicon

The interaction of vacancies with 30 degrees and 90 degrees partial dislocations in silicon is examined. In particular, the structures and binding energies are calculated using hydrogen-terminated clusters and local density-functional theory. Moreover the electronic structure is determined using supercells containing dislocation dipoles. Vacancies are found to have binding energies of approximately 2.0 eV and 0.9 eV to 90 degrees and 30 degrees partials, respectively. The elastic strain field of the partials makes the fourfold vacancy reconstruct, which essentially clears the fundamental gap.