Valence-band parameters and hole mobility of Ge-Si alloys-theory

Abstract

Using the Lawaetz method the authors have estimated the k.p band parameters and determined the band structure near the valence-band edge of the Ge-Si alloy system. They have also obtained the coupling constants between holes and phonons by Wiley's method. Using these two kinds of parameters they have calculated the time for relaxation of holes due to the lattice scattering, where they have taken into account the nonpolar optical phonon, the impurity scattering due to ionised and neutral centres and also the alloy scattering. The intervalence-band interactions are shown to produce the complicated temperature dependence of the hole mobility.