Acceptor ground states in nearly cubic semiconductors

The splitting of acceptor ground states and their energy shift under the influence of uniaxial stress or noncubic crystal fields are calculated on the basis of a spherical or cubic valence band structure with large spin‐orbit splitting. The knowledge of the band parameters and the perturbation induced valence band splitting is sufficient to estimate the energies of the ground and first excited acceptor states. The experimental determination of the deformation potentials of three shallow acceptors in GaAs as well as the quadratic dependence of the acceptor ground states on the uniaxial stress provide a direct check of the calculations.