Ab initio investigations on the dislocation core properties in zinc-blende semiconductors

Using total energy ab initio methods, we investigated the core properties of partial dislocations in GaAs. The calculations were based on the density functional theory and the pseudopotential model. We addressed the microscopic structure of the 30°-partial and the 90°-partial dislocations. In the case of a 90° partial, the double-period reconstruction is energetically more favourable than the single-period reconstruction. Our results also indicate a substantial lowering in the formation energy of an intrinsic antisite defect in a dislocation core as compared to the defect in crystalline GaAs.