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Hong Tran N.,McGill University | Huy Le B.,McGill University | Fan S.,McGill University | Zhao S.,McGill University | And 5 more authors.
Applied Physics Letters | Year: 2013

We report on a detailed study of the structural and optical properties of nonstoichiometric nitrogen-rich InN grown on sapphire substrates, by migration enhanced afterglow deposition. The samples were polycrystalline, with the presence of InN dots. Unusually strong photoluminescence emission was measured at cryogenic temperatures, with the peak energy at ∼0.68 eV. Detailed analysis further shows that the sample has very low residual electron density in the range of ∼1016 cm-3 at temperatures below 20 K. © 2013 AIP Publishing LLC. Source


Butcher K.S.A.,Macquarie University | Butcher K.S.A.,Meaglow Ltd. | Chen P.P.-T.,Macquarie University | Downes J.E.,Macquarie University
Applied Physics Letters | Year: 2012

For some InN films large amounts of excess nitrogen are seen at low growth temperatures. Recent studies have revised downward the defect formation energies for several forms of nitrogen rich point-defects in InN. Here we calculate an activation energy of 0.4 ± 0.1 eV for the thermally activated removal of much of the excess nitrogen, believed to be interstitial nitrogen. This low energy barrier is shown to support the case for a low defect formation energy of the same native defect, although it is pointed out that non-equilibrium plasma based conditions are required to reach these lower defect formation energies. © 2012 American Institute of Physics. Source


Gergova R.,Lakehead University | Butcher K.S.A.,Meaglow Ltd. | Butcher K.S.A.,Leibniz Institute for Crystal Growth | Binsted P.W.,Lakehead University | Gogova D.,Leibniz Institute for Crystal Growth
Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures | Year: 2014

In this paper, the authors report on epitaxial thin InN layers grown on commercially available undoped GaN buffer layers and on Ga2O 3 interlayers produced by Migration-Enhanced Afterglow Epitaxy (MEAglow). The InN layers reported here, also grown by the MEAglow technique, are 100-200 nm thick and have a measured absorption edge between 1.3 and 1.95 eV. Advancements in the growth process have now allowed the authors to improve the InN layers so that the growth has excellent two-dimensional morphology. Scanning electron microscope images show that terracing is strongly evident for samples grown on GaN templates. Atomic force microscopy shows a maximum height of the steps of about 2 nm. For the samples grown on Ga2O 3, crystal quality is superior to InN grown on AlN buffers with similar thicknesses. X-ray diffraction ω-2θ measurements indicate a full width of half maximum (FWHM) of 342-389 arcseconds for these extremely thin layers; a good part of this x-ray diffraction FWHM is likely due to residual strain between the InN and GaN or between the InN and oxide. © 2014 American Vacuum Society. Source


Terziyska P.T.,Lakehead University | Butcher K.S.A.,Lakehead University | Butcher K.S.A.,Meaglow Ltd. | Gogova D.,Leibniz Institute for Crystal Growth | And 4 more authors.
Materials Letters | Year: 2013

Self-catalytic growth of InN nanopillars on (0001) sapphire is reported under In-rich conditions, using the Migration Enhanced Afterglow (MEAglow) growth technique. The nanopillars are up to 2 μm in length and 100-200 nm in diameter, terminated with an In-metal droplet on the top, with growth direction and preferred orientation along the InN c-axis. The shape of the nanopillars is cylindrical and their diameter is determined by the diameter of the In-metal droplet. X-ray diffraction measurements indicate the presence of both cubic and hexagonal InN, with very good crystalline quality. The room temperature Raman spectrum shows the presence of the A1(TO), E2(high) and A1(LO) phonon modes of the hexagonal InN. © 2013 Elsevier B.V. Source


Terziyska P.T.,Lakehead University | Terziyska P.T.,Bulgarian Academy of Science | Butcher K.S.A.,Lakehead University | Butcher K.S.A.,Meaglow Ltd. | And 3 more authors.
Applied Surface Science | Year: 2015

Vertically oriented InN nanorods were grown on selective areas of unintentionally patterned c-oriented sapphire substrates exhibiting sharp needles that preferentially accommodate In-metal liquid droplets, using Migration Enhanced Afterglow (MEAglow) growth technique. We point out that the formation of AlN needles on selected areas can be reproduced intentionally by over-nitridation of unmasked areas of sapphire substrates. The liquid indium droplets serve as a self-catalyst and the nanorods grow from the supersaturated indium melt in the droplet in a vertical direction. X-ray diffraction measurements indicate the presence of hexagonal InN only, with preferred orientation along (0 0 0 1) crystal axis, and very good crystalline quality. The room temperature Raman spectrum shows the presence of the A1(TO), E2(high) and A1(LO) phonon modes of the hexagonal InN. © 2015 Elsevier B.V. All rights reserved. Source

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