Valence-band lineups at highly strained SiInP, GeInAs, and SiGe interfaces

Abstract

This paper reports a theoretical study on the valence-band lineups at highly strained SiInP, GeInAs and SiGe interfaces by combining average bond energy theory and deformation potential method. The effect of the shallow d-orbitals in In-atom on the valence-band lineup is investigated. Three typical strain conditions are calculated for each interface system. The dependence of the lineups on the strain condition are demonstrated quantitatively. It is found that the offset between the average energies of valence-band maximum is affected little by the elastic strain for the three interface systems, however, those between the topmost valence-band states (ΔE v ) is closely related to the strain condition. The change regions of ΔE v are −0.39∼−1.23eV, −0.49∼−1.32eV and 0.22∼0.74eV for SiInP, GeInAs and SiGe systems, respectively. It is demonstrated that this strong dependence is due to the uniaxial component of the strain and its interaction with the spin-orbit splitting. Our results for SiGe system are in good agreement with the data given by x-ray photoemission measurement and supercell selfconsistent calculations by ab initio pseudopotential methods. Our results for Ge InP system are consistent with the experimental data of synchrotron radiation photoemission.