Group-Theoretical Study of Double Acceptors in Semiconductors under Uniaxial Stress

We have made a study of the energy splittings, selection rules, and relative intensities of the optical transitions associated with neutral group-II acceptors in group-IV semiconductors under uniaxial stress. The exact discussion is simplified by describing the double acceptor in a self-consistent-field approximation. Our treatment is applied to the analysis of experimental results for neutral zinc in germanium under uniaxial stress parallel to the directions $〈100〉$ and $〈111〉$. A comparison with the experimental work of Jones and Fisher permits us to determine the level ordering under stress. The relative intensities of the stress-induced $D$ lines can be fitted, in this approximation, with only two real parameters.