Cubic-phase epilayers were grown, using radio-frequency plasma-assisted molecular beam epitaxy, onto (100)GaAs and were investigated by means of secondary ion mass spectroscopy and low-temperature photoluminescence. Accumulation of Mg at the GaN/GaAs interface was observed. Low-temperature photoluminescence spectra revealed several well-separated lines. As well as a shallow acceptor level at 0.230eV, additional Mg-related deep defect levels indicated the incorporation of Mg at off-Ga sites, or as complexes.

Incorporation and Optical Properties of Magnesium in Cubic GaN Epilayers. D.J.As, T.Simonsmeier, B.Schöttker, T.Frey, D.Schikora, W.Kriegseis, W.Burkhardt, B.K.Meyer: Applied Physics Letters, 1998, 73[13], 1835-7