Optically detected magnetic-resonance mapping on the yellow luminescence in GaN

A mapping investigation was performed with photoluminescence-detected elect ron paramagnetic resonance (PL-EPR) via the yellow luminescence on nominall y undoped, metal-organic vapor-phase epitaxy-grown GaN on sapphire. From th e results, it is concluded that the PL-EPR signals observed in these sample s represent different recombination channels which contribute to the yellow luminescence. Therefore, our results do not support the model of Glaser [P hys. Rev. B 51, 13326 (1995)] for the mechanism of the yellow luminescence proposed recently. (C) 2000 American Institute of Physics. [S0003-6951(00)0 1714-9].