The N-pair O defect was studied by means of the infra-red absorption spectroscopy of samples that had been implanted with various combinations of 14N, 15N, 16O and 17O. The results provided evidence of the involvement of N and O in the defect, and showed that the impurity atoms which comprised the defects were only weakly coupled. First-principles calculations of various models for the N-pair O defect were performed and were compared with experimental data. On the basis of these results, a model was proposed which consisted of a bridging O atom that was adjacent to the N pair.

F.B.Rasmussen, S.Oberg, R.Jones, C.Ewels, J.Goss, J.Miro, P.Deak: Materials Science and Engineering B, 1996, 36[1-3], 91-5