Perturbed angular correlation measurements in Indium implanted GaN and AlN have shown that after annealing up to 50% of the In probes occupy relatively undisturbed substitutional group III sites at 293K while the remaining fraction traps a nearest neighbour point defect. Above 293K this fraction decreased strongly until, at 1100K, all In probes were found in undisturbed substitutional sites. The effect was completely reversible. A model involving an Indium–nitrogen vacancy complex was suggested to explain this behaviour. Possibly this complex could act as radiative recombination center or as seed for phase segregation during growth.

Stable In-Defect Complexes in GaN and AlN. J.Schmitz, J.Niederhausen, J.Penner, K.Lorenz, E.Alves, R.Vianden: Physica B, 2009, 404[23-24], 4866-9