Observation of optically detected magnetic resonance in GaN films

Abstract

Optically detected magnetic resonance has been observed from GaN. Two magnetic resonances have been detected on the 2.2 eV-deep photoluminescence band. The first resonance is sharp [full width at half-maximum (FWHM) ∼2.2 mT] with g∥=1.9515±0.0002 and g⊥=1.9485±0.0002 and is assigned to conduction electrons, in agreement with recent electron paramagnetic resonance (EPR) studies of similar samples. The second feature, which has not been seen by EPR, is much broader (FWHM∼13 mT) with g∥=1.989±0.001 and g⊥=1.992±0.001. These parameters indicate a deep state. A tentative assignment is made to a deep state associated with the N vacancy.