The introduction of vacancy-type point defects by Si doping of InN grown by plasma-assisted molecular beam epitaxy was studied using a mono-energetic positron beam. Using combined positron lifetime and Doppler broadening measurements, compensating In-vacancy (VIn) acceptors were identified. With increasing Si doping, increased formation of VIn was observed, up to a concentration of 7 x 1017/cm3 in the highest-doped sample (6.6 x 1020/cm3). Strong inhomogeneity of the defect profile, with a marked increase in the VIn concentration towards the layer/substrate interface was detected. Larger vacancy clusters containing several VIn were formed near to the interface.

In-Vacancies in Si-Doped InN. C.Rauch, F.Reurings, F.Tuomisto, T.D.Veal, C.F.McConville, H.Lu, W.J.Schaff, C.S.Gallinat, G.Koblmüller, J.S.Speck, W.Egger, B.Löwe, L.Ravelli, S.Sojak: Physica Status Solidi A, 2010, 207[5], 1083-6