Using a self-consistent perturbation theory developed in the first two papers of this series we have calculated the deformation potentials for a general strain for points of high symmetry ($\Gamma$, $X$, and $L$) in the conduction and valence bands of Si. We compare our calculated results with experimental values for (1) hydrostatic-pressure dependence of various energy gaps, (2) uniaxial-strain dependence of the splitting of the fourfold degenerate level at the top of the valence band, and (3) uniaxial strain dependence of the splitting of the degeneracy between equivalent valleys at the bottom of the conduction band. The agreement between theory and experiment ranges from fair to good.

• Received 25 June 1963

DOI:https://doi.org/10.1103/PhysRev.132.1080