Positron annihilation spectroscopy was used to study the effect of various growth conditions upon vacancy formation in In-polar InN grown by plasma-assisted molecular beam epitaxy. It was found that the stoichiometric conditions had little effect upon the In vacancy concentration in the thin films. On the other hand, the optimization of the GaN buffer used for initiating InN growth led to a lower In vacancy concentration. This indicated that the structural quality of the material dictated the In vacancy formation in InN, while the thermodynamic and kinetic effects have a less important role, contrary to what was observed in, e.g., GaN.

Vacancy Defects Probed with Positron Annihilation Spectroscopy in In-Polar InN Grown by Plasma-Assisted Molecular Beam Epitaxy - Effects of Growth Conditions. F.Reurings, F.Tuomisto, C.S.Gallinat, G.Koblmüller, J.S.Speck: Physica Status Solidi C, 2009, 6[S2], S401-4