A detailed study on the optical quality of atmospheric pressure metalorganic vapor phase epitaxy grown GaAs(1−x)Nx epilayers (on GaAs substrates) in which the N incorporation is accomplished using dimethylhydrazine precursor is reported. We show here that the poor optical quality of these as-grown layers can be significantly improved by carefully planned post-growth heat treatments. Optical data are presented to demonstrate unambiguously that such treatments affect in no way the physical properties of these metastable layers (no phase separation) and that the improvement of their optical quality is closely connected to the incorporation behavior of N in this growth method.

Growth and properties of GaNAsSb alloys are investigated and compared with those of other dilute III-N-V alloys. Similar properties are observed including very high bandgap bowing, carrier localization at low temperature, sensitivity to thermal annealing and passivation of N-related electronic states by hydrogen. On the other hand, we point out some features of this alloy system and evaluate its potential for device applications. Probably, GaNAsSb can achieve emission at longer wavelengths than GaInNAs alloys grown to date. Its conduction-and valence-band offsets can be independently tuned by adjusting the N and Sb composition, respectively. Since this compound has a single group III element, its electronic structure should be less dependent on alloy configuration than GaInNAs.

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GaAsN layers with good structural quality and surface morphology have been successfully grown on a GaAs substrate using atmospheric pressure metal organic vapor phase epitaxy. A new combination of precursors namely, dimethylhydrazine for nitrogen and tertiarybutylarsine instead of conventional arsine for arsenic, greatly facilitated growths at temperatures as low as 500 °C. Layers with N content as high as 3% and corresponding to room temperature photoluminescence (PL) peak wavelength of 1.17 μm (1.064 eV) have been obtained.