Strong blue emission from As doped GaN grown by molecular beam epitaxy

Arsenic doped GaN grown by molecular beam epitaxy has been studied by room temperature photoluminescence. In addition to the wurzite band edge transit ion, luminescence from the cubic phase and very strong blue emission at sim ilar to 2.6 eV are observed. The intensities of the blue and the cubic band edge emissions have a power law dependence on the As-2 flux. The formation of the cubic phase has been explained by the initial formation of GaAs bef ore substitution of the As by the more reactive N. The intensity of the blu e emission at room temperature of the As doped samples is more than an orde r of magnitude stronger than the band edge emission in undoped samples. (C) 2000 American Institute of Physics. [S0003-6951(00)01742-3].