GaN nanowires with pentagon shape cross-section by ammonia-source molecular beam epitaxy

Growth of GaN by gas-source molecular beam epitaxy by ammonia and by plasma generated nitrogen radicals

We will present a comparison between GaN grown on cand r-plane sapphire by gas-source molecular beam epitaxy (GSMBE) using solid source elemental Ga with untracked ammonia (NH,). Improved GaN film quality was found for samples grown at substrate temperatures above 700°C with optimized temperatures at 780°C. GaN deposited on a low-temperature ( 350°C) GaN buffer layer grown using an if-plasma ra...

GaN and InGaN Nanowires on Si Substrates by Ga-Droplet Molecular Beam Epitaxy

Molecular beam epitaxy growth of GaN and InGaN nanowires is accomplished on Si (111) substrates using Ga-droplet nucleation. Typical diameters range from 25-80 nm and lengths can be varied by increasing the growth time; the growth rate is ~0.25 microns/hour. The nanowires have been characterized structurally and optically. Photoluminescence spectra show band-edge emission of GaN nanowires cente...

Nucleation mechanism of GaN nanowires grown on (111) Si by molecular beam epitaxy.

We have performed a real-time in situ x-ray scattering study of the nucleation of GaN nanowires grown by plasma-assisted molecular beam epitaxy on AlN(0001)/Si(111). The intensity variation of the GaN diffraction peak as a function of time was found to exhibit three different regimes: (i) the deposition of a wetting layer, which is followed by (ii) a supralinear regime assigned to nucleation of...

Magnesium incorporation in GaN grown by molecular-beam epitaxy

A pronounced dependence of Mg incorporation on surface polarity was observed in a series of Mg step-doped epitaxial GaN layers grown by rf-plasma-assisted molecular-beam epitaxy. Incorporation was studied for both ~0001!, or Ga-polarity and (0001̄) or N-polarity orientations. Up to a factor of 30 times more Mg was incorporated in Ga-polarity layers under certain conditions, as determined by seco...

Growth of GaN on porous SiC by molecular beam epitaxy