Identification of the Nitrogen Split Interstitial
Abstract
Combining electron paramagnetic resonance, density functional theory, and positron annihilation spectroscopy (PAS), we identify the nitrogen interstitial defect in GaN. The isolated interstitial is unstable and transforms into a split interstitial configuration (N-N)N. It is generated by particle irradiation with an introduction rate of a primary defect, pins the Fermi level at EC-1.0 eV for high fluences, and anneals out at 400 °C. The associated defect, the nitrogen vacancy, is observed by PAS only in the initial stage of irradiation.