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

Abstract

GaN 1−y As y epitaxial alloy samples with [N]≫[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.