Defects observed by optical detection of electron paramagnetic resonance in electron-irradiatedp-type GaN

This is the authors' abstract. We don't add key points for this paper.

Irradiation of p-type (Mg-doped) GaN in situ at 4.2 K by 2.5 MeV electrons reduces the visible luminescence and creates a broad luminescence band in the infrared at ~0.95 eV. Upon annealing at 180 K, partial recovery of the visible luminescence occurs and a well resolved $S=1$ center is observed by optical detection of electron paramagnetic resonance to emerge in it. Labeled $L8,$ its D tensor suggests a Frenkel excitonic state with the two $s=1/2$ particles separated along the off-c-axis Ga-N bond direction by the Ga-N bond distance. Other centers are weakly observed in the infrared band which anneal at room temperature.