Electronic structure and hyperfine interactions for deep donors and vacancies in II-VI compound semiconductors

We present ab initio total-energy calculations for group-IV donors, vacancies and cation self-interstitials in cubic II-VI compound semiconductors. The calculations have been performed using the linear muffin-tin orbital method in the atomic-sphere approximation, with a particular emphasis on hyperfine and ligand hyperfine interactions. Our theoretical hyperfine interaction results for paramagnetic point defect states which transform. according to the A(1) irreducible representation agree fairly well with the results obtained experimentally by electron paramagnetic resonance. There are two marked exceptions, the selenium vacancy in ZnSe and the tellurium vacancy in CdTe, for which there is an order of magnitude discrepancy. We conclude that the identification of these defects must be highly questionable.