Self-assembly of β-GaN/MgO nanobars

Self assembly of cubic GaN of nanometric size structures, bar-like in appearance, or nanobars, is observed when high fluxes of Si atoms are present during the growth of GaN thin films. The self assembled cubic GaN nanobars were grown by Gas Source Molecular Beam Epitaxy (GSMBE) on a GaN [001] buffer layer. The buffer layer of β-GaN grew as rectangular mosaics with borders along the crystallographic directions [110] and [1-10] on MgO substrates. The self assembled nanobars are 20-60 nm in width and 500-1000 nm in length. The crystalline structure of the nanobars is cubic, as revealed by Reflected High Energy Electron Diffraction during the growth process and X-ray diffraction studies. These nanobars show photoluminescent transitions centered at 3.45 eV, this is 0.17 eV higher than in bulk cubic GaN (3.28 eV). This energy shift may be attributed to the lateral confinement on the donor states in these silicon enriched of β-GaN nanobars. © 2012 American Scientific Publishers. All rights reserved.

GaN/MgO nanobars; Gas source molecular beam epitaxy; Photoluminescence; Self-assembly

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