First-principles calculations on atomic and electronic structures of misfit dislocations in InAs/GaAs(1 1 0) and GaAs/InAs(1 1 0) heteroepitaxies

We investigated the atomic and electronic structures of the misfit dislocations of InAs/GaAs(1 1 0) and GaAs/InAs(1 1 0) heterointerfaces by first-principles calculations and scanning tunneling microscopy tSTM). The calculated results show that the core confined at the InAs/GaAs(1 1 0) heterointerface has five-fold coordinated In atoms. The surface just above the dislocation line was depressed and the calculated vertical displacement was about 0.52 angstroms when the InAs epilayer thickness is 4 ML, which is in good agreement with the STM observations. In the GaAs/InAs heteroepitaxy, core structures drastically change with the increase of GaAs epilayer thickness.