Mechanical and electronic properties of nanoscale semiconductors studied by density functional TB and path probability methods

Abstract

The atomistic properties of semiconductor heterostructures and quantum does including misfit dislocations are studied using the density-functional tight-binding (TB) method. Atomic structures of misfit dislocations both edge type 1/2 <110> (001) and 60° dislocations in the semiconductor heterostructures, like Si-Ge, GaAs/Si, InP/GaAs and ZnSe/GaAs (001) systems are calculated by using order of N[O(N)] method. The path probability method (PPM) is used to study the influence of the interface disorder on the atomistic properties of the semiconductor heterostructures. The critical layer thickness he for the generation of misfit dislocations has been calculated both for the sharp and diffuse (interface mixing) interfaces. The plastic stress relaxation, especially the role of misfit dislocations with respect to their nucleation and propagation behavior is also studied within the framework of the present theoretical methods.