Electronic band structure calculations for biaxially strained Si, Ge, and III–V semiconductors

Electronic band structure and effective masses for relaxed and biaxially strained Si, Ge, III–V compound semiconductors (GaAs, GaSb, InAs, InSb, InP) and their alloys (InxGa1−xAs, InxGa1−xSb) on different interface orientations, (001), (110), and (111), are calculated using nonlocal empirical pseudopotential with spin-orbit interaction. Local and nonlocal pseudopotential parameters are obtained by fitting transport-relevant quantities, such as band gap and deformation potentials, to available experimental data. A cubic-spline interpolation is used to extend local form factors to arbitrary q and to obtain correct workfunctions. The nonlocal and spin-orbit terms are linearly interpolated between anions and cations for III–V semiconductors. The virtual crystal approximation is employed for the InxGa1−xAs and InxGa1−xSb alloys and deformation potentials are determined using linear deformation-potential theory. Band gap bowing parameters are extracted using least-square fitting for relaxed alloys and for strained InxGa1−xAs on (001), (110), and (111) InP. The dependence on biaxial strain of the electron and hole effective masses at the symmetry points Γ, X, and L exhibits a continuous variation at Γ and L but sudden changes appear at Δ minima caused by the flatness of the dispersion along the Δ line near the minimum.