Mg acceptors in GaN: Dependence of the g-anisotropy on the doping concentration

Abstract Mg acceptors in GaN epitaxial layers grown by metal–organic vapour-phase epitaxy were investigated by optically detected magnetic resonance (ODMR) spectroscopy. The magnetic resonances were detected on the magnetic circular dichroism (MCD) of the acceptor bound exciton (Mg 0 X) in the near bandgap region, and in the infrared spectral range on the MCD of the hole ionisation transition Mg 0 + hν →Mg − + h VB . The observed g -values of the Mg 0 acceptors range for g || from 2.102 to 2.065 and for g ⊥ from 1.94 to 2.00, respectively. These variations depend on the Mg doping concentration.