The possibility was addressed that the hole concentration saturation which was observed in the p-type doping of this material was caused by the formation of complexes between the substitutional acceptor and charged native defects such as Se vacancies and Zn interstitials. A simple model for compensation was presented, in which the relevant parameters were computed from first principles. A large lattice relaxation which was associated with the Se vacancy and the corresponding complex lowered their formation energy significantly. However, the large binding energy of the acceptor-Zn-interstitial complex was expected to make it a more efficient compensator.

A.García, J.E.Northrup: Physical Review Letters, 1995, 74[7], 1131-4