A short review and comparison was presented of results obtained in positron annihilation spectroscopy studies of vacancy defects in AlN, GaN and InN. The combination of positron lifetime and Doppler broadening techniques with theoretical calculations had provided the means to deduce both the identities and the concentrations of the vacancies in these materials, while performing measurements as a function of temperature had given information on the charge states of the detected defects. The III-sublattice vacancies were common defects in all the III-nitrides, and they compensate donors either by forming vacancy-impurity complexes or by providing deep states for electrons. In some cases, N vacancies had also been observed.

Vacancy Defects in III-Nitrides: What Does Positron Annihilation Spectroscopy Reveal? F.Tuomisto: Journal of Physics - Conference Series, 2011, 265[1], 012003