Electrically active centers in partial dislocations in semiconductors

We carried out a theoretical investigation on the properties of antiphase defects, or core reconstruction defects, in a 30degrees partial dislocation in Si and GaAs. The calculations were performed using ab initio total energy methods, based on the density functional theory. From the results on formation energies of these reconstruction defects, we predict that the concentration of dislocation-related electrically active centers should be considerably larger in GaAs than in Si. We also find that an antiphase defect in silicon may exist in positive, neutral, or negative charge states, with a Mott-Hubbard potential of 0.30 eV. (C) 2001 Elsevier Science B.V. All rights reserved.