Electronic structure of strained layer [formula omitted] superlattices from tight binding theory

Abstract

The electronic structure of strained layer Si Ge xSi 1− x superlattices is calculated by means of the empirical tight binding method. Coherently strained Si Ge 0.5 Si 0.5 superlattices grown on Ge ySi 1−y(001) substrates are considered. The effect of strain (y), band offsets and layer thicknesses on superlattice bandstructures and wave functions is studied. A strain-induced type I — type II transition is obtained.