Stillinger-Weber potentials which accurately described the elastic constants of CdTe and GaAs were developed. These potentials were then used to investigate the misfit dislocation structure at a CdTe(001)/GaAs(001) interface. On the basis of these calculated structures, simulated high-resolution transmission electron microscopic images were compared with experimentally observed images. It was found that, although the exact energetics of the interface were not provided by these potentials, dislocation stand-off was more strongly influenced by the Poisson expansion or by contraction of the individual materials. The best agreement between experimentally observed and simulated images was obtained when the dislocations occurred at the interface, with no stand-off. The calculated structures indicated that the misfit dislocation structure which was observed along the [110] direction was different, to that which was observed along the [1¯10] direction, if the initial monolayer of material (which was here thought to be Te) misfitted the substrate. This was attributed to the tetrahedral nature of the constituent materials, and was not directly related to the zincblende structure.

J.E.Angelo, M.J.Mills: Philosophical Magazine A, 1995, 72[3], 635-49