Optically detected magnetic resonance of shallow donor – shallow acceptor and deep (2.8–3.2 eV) recombination from Mg-doped GaN

Abstract

Comprehensive photoluminescence (PL) and optically detected magnetic resonance (ODMR) experiments have been performed on a set of GaN epitaxial layers doped with Mg from 2.5×1018 to 5.0×1019cm−3. Strong shallow donor–shallow acceptor recombination at 3.27eV is observed from the lowest-doped sample while broad emission bands at 2.8 and 3.2eV were found from the more heavily doped films. ODMR at 24GHz on these bands reveals evidence for effective-mass shallow donors and Mg-related acceptors with unique g-tensors, including the first observation of the resonance parameters (g||=2.113(4) and g⊥=1.970(5)) associated with Mg shallow acceptors in GaN.