Epitaxial GaN1-yAsy layers with high As content grown by metalorganic vapor phase epitaxy and their band gap energy

GaN1-yAsy epitaxial alloy samples with [N]much greater than[As] were grown by metalorganic vapor phase epitaxy. The range of As content achieved, up to y=0.067, greatly extends the range of achievable As levels to values that are well within the miscibility gap of the GaN-GaAs system. The single-phase epitaxial nature of the alloy samples was confirmed by x-ray diffraction. The As-content dependence of the band gap was determined by optical absorption measurements. A highly-bowed bandgap was observed as a function of the As content, and a refined value of the bowing parameter of 16.9+/-1.1 eV was determined. (C) 2004 American Institute of Physics.