Abstract
We investigate the physics of the core reconstruction and associated structural excitations (reconstruction defects and kinks) of dislocations in silicon, using a linear-scaling density-matrix technique. The two predominant dislocations (the and partials) are examined, focusing for the case on the single-period core reconstruction. In both cases, we observe strongly reconstructed bonds at the dislocation cores, as suggested in previous studies. As a consequence, relatively low formation energies and high migration barriers are generally associated with reconstructed (dangling-bond-free) kinks. Complexes formed of a kink plus a reconstruction defect are found to be strongly bound in the partial, while the opposite is true in the case of partial, where such complexes are found to be only marginally stable at zero temperature with very low dissociation barriers. For the partial, our calculated formation energies and migration barriers of kinks are seen to compare favorably with experiment. Our results for the kink energies on the partial are consistent with a recently proposed alternative double-period structure for the core of this dislocation.
- Received 16 July 1997
DOI:https://doi.org/10.1103/PhysRevB.57.10388
©1998 American Physical Society