Bulk lattice parameter and band gap of cubic In sub(x)Ga sub(1-x)N (001) alloys on MgO (100) substrates

• Published in: Journal of crystal growth Vol. 418; pp. 120 - 125
• Main Authors: Garcia, V D Compean, Hinostroza, I E Orozco, Echavarria, A Escobosa, Luna, E Lopez, Rodriguez, A G, Vidal, M A
• Format: Journal Article
• Language: English
• Published: 05-05-2015
• Subjects: Alloys; Crystal growth; Diffraction; Energy gap; Gallium nitrides; Lattice parameters; Magnesium oxide; Transmittance
• ISSN: 0022-0248
• DOI: 10.1016/j.jcrysgro.2015.02.033

In sub(x)Ga sub(1-x)N (001) ternary alloys were grown on GaN/MgO (100) substrates in a plasma assisted molecular beam epitaxy system. We determined the in-plane [001] and in-growth [110] lattice parameters, as well as the bulk lattice parameter of the alloys for different In concentrations by high resolution X-ray diffraction. The In concentration was determined assuming Vegard's law for the alloy lattice parameter. The optical energy gap of In sub(x)Ga sub(1-x)N has been determined by transmittance measurements from absorption edges for several In concentrations. Our results show that the alloys have a direct band gap for all In concentrations and a bowing parameter b = 1.84.