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Structural and Chemical Evolution of the Spontaneous Core-Shell Structures of Al x Ga1-x N/GaN Nanowires

  • Rabie Fath Allah (a1), Teresa Ben (a1) and David González (a1)


A study by electron microscopy techniques of the structural and compositional properties of Al x Ga1-x N/GaN nanowire (NW) heterostructures on Si(111) is presented. Al x Ga1-x N depositions grown without catalyst by plasma-assisted molecular beam epitaxy were designed to form NWs in the range of 0.20<x<0.40 with different lengths and growth temperatures. The NWs exhibit a well-defined core-shell radial structure with a complex chemical distribution along and across the growth direction that finally affects the NW morphology. All the wires have an initial stage with a maximum Al content in the core slightly above the GaN/Al x Ga1-x N interface, which initially decreases exponentially with the NW height depending on the nominal Al content and the growth temperature. In longer NWs, this trend changes and evolves increasing both the Al/Ga ratio and the core diameter as well as sharpening the shell. Adatom surface kinetic differences and the geometrical shadow effect during the growth are the probable drivers of this behavior.


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Allah, R.F., Ben, T., Songmuang, R. & González, D. (2012). Imaging and analysis by transmission electron microscopy of the spontaneous formation of Al-rich shell structure in AlxGa1-xN/GaN nanowires. Appl Phys Express 5(4), 045002045003.
Asif Khan, M. (2005). Nitride UV devices. Jpn J Appl Phys 44(10), 71917206.
Averbeck, R. & Riechert, H. (1999). Quantitative model for the MBE-growth of ternary nitrides. Phys Status Solidi A 176(1), 301305.
Bhattacharyya, A., Moustakas, T.D., Zhou, L., Smith, D.J. & Hug, W. (2009). Deep ultraviolet emitting AlGaN quantum wells with high internal quantum efficiency. Appl Phys Lett 94(18), 181907.
Boxberg, F., Søndergaard, N. & Xu, H.Q. (2010). Photovoltaics with piezoelectric core−shell nanowires. Nano Lett 10(4), 11081112.
Calarco, R., Meijers, R.J., Debnath, R.K., Stoica, T., Sutter, E. & Luth, H. (2007). Nucleation and growth of GaN nanowires on Si(111) performed by molecular beam epitaxy. Nano Lett 7(8), 22482251.
Debnath, R.K., Meijers, R., Richter, T., Stoica, T., Calarco, R. & Luth, H. (2007). Mechanism of molecular beam epitaxy growth of GaN nanowires on Si(111). Appl Phys Lett 90(12), 123117.
Furtmayr, F., Teubert, J., Becker, P., Conesa-Boj, S., Morante, J.R., Chernikov, A., Schäfer, S., Chatterjee, S., Arbiol, J. & Eickhoff, M. (2011). Carrier confinement in GaN/AlxGa1−xN nanowire heterostructures (0&lt;x≤ 1). Phys Rev B 84(20), 205303.
Glas, F. (2006). Critical dimensions for the plastic relaxation of strained axial heterostructures in free-standing nanowires. Phys Rev B 74(12), 121302.
Guo, Y.-N., Xu, H.-Y., Auchterlonie, G.J., Burgess, T., Joyce, H.J., Gao, Q., Tan, H.H., Jagadish, C., Shu, H.-B., Chen, X.-S., Lu, W., Kim, Y. & Zou, J. (2013). Phase separation induced by Au catalysts in ternary InGaAs nanowires. Nano Lett 13(2), 643650.
Harrison, W.A. (1989). Electronic Structure and the Properties of Solids : The Physics of the Chemical Bond . San Francisco: Dover Publications.
Jindal, V., Grandusky, J., Tripathi, N., Tungare, M. & Shahedipour-Sandvik, F. (2007). Density functional calculations of the binding energies and adatom diffusion on strained AlN (0001) and GaN (0001) surfaces. MRS Online Proc Library 1040.
Jindal, V., State University of New York at Albany (2008). Development of III-Nitride Nanostructures by Metal-Organic Chemical Vapor Deposition. Albany: State University of New York at Albany.
Kikuchi, A., Kawai, M., Tada, M. & Kishino, K. (2004). InGaN/GaN multiple quantum disk nanocolumn light-emitting diodes grown on (111) Si substrate. Jpn J Appl Phys 43(Part 2, 12A), L1524L1526.
Kim, H.-M., Cho, Y.-H., Lee, H., Kim, S.I., Ryu, S.R., Kim, D.Y., Kang, T.W. & Chung, K.S. (2004). High-brightness light emitting diodes using dislocation-free indium gallium nitride/gallium nitride multiquantum-well nanorod arrays. Nano Lett 4(6), 10591062.
Li, Y., Xiang, J., Qian, F., Gradečak, S., Wu, Y., Yan, H., Blom, D.A. & Lieber, C.M. (2006). Dopant-free GaN/AlN/AlGaN radial nanowire heterostructures as high electron mobility transistors. Nano Lett 6(7), 14681473.
Lim, S.K., Tambe, M.J., Brewster, M.M. & Gradečak, S. (2008). Controlled growth of ternary alloy nanowires using metalorganic chemical vapor deposition. Nano Lett 8(5), 13861392.
Neumann, H. (1995). J.H. Edgar (ed.). Properties of Group III Nitrides. (EMIS Datareviews Series No. 11). INSPEC, The Institution of Electrical Engineers, London 1994. 302 Seiten, 121 Abbildungen, 77 Tabellen. ISBN 0–85296–818–3. Crystal Res Technol 30(7), 910.
Park, Y.S., Hwang, B.R., Lee, J.C., Im, H., Cho, H.Y., Kang, T.W., Na, J.H. & Park, C.M. (2006). Self-assembled AlxGa1−x N nanorods grown on Si(001) substrates by using plasma-assisted molecular beam epitaxy. Nanotechnology 17(18), 4640.
Pennycook, S.J. & Boatner, L.A. (1988). Chemically sensitive structure-imaging with a scanning transmission electron microscope. Nature 336(6199), 565567.
Pierret, A., Bougerol, C., Murcia-Mascaros, S., Cros, A., Renevier, H., Gayral, B. & Daudin, B. (2013). Growth, structural and optical properties of AlGaN nanowires in the whole composition range. Nanotechnology 24(11), 115704.
Qian, F., Gradečak, S., Li, Y., Wen, C.-Y. & Lieber, C.M. (2005). Core/multishell nanowire heterostructures as multicolor, high-efficiency light-emitting diodes. Nano Lett 5(11), 22872291.
Qian, F., Li, Y., Gradečak, S., Wang, D., Barrelet, C.J. & Lieber, C.M. (2004). Gallium nitride-based nanowire radial heterostructures for nanophotonics. Nano Lett 4(10), 19751979.
Ristić, J., Calleja, E., Sánchez-García, M.A., Ulloa, J.M., Sánchez-Páramo, J., Calleja, J.M., Jahn, U., Trampert, A. & Ploog, K.H. (2003). Characterization of GaN quantum discs embedded in AlxGa1-xN nanocolumns grown by molecular beam epitaxy. Phys Rev B 68(12), 125305.
Sekiguchi, H., Kishino, K. & Kikuchi, A. (2008). GaN/AlGaN nanocolumn ultraviolet light-emitting diodes grown on n-(111) Si by RF-plasma-assisted molecular beam epitaxy. Electron Lett 44(2), 151152.
Shitara, T., Neave, J.H. & Joyce, B.A. (1993). Reflection high-energy electron diffraction intensity oscillations and anisotropy on vicinal AlAs(001) during molecular-beam epitaxy. App Phys Lett 62(14), 16581660.
Sköld, N., Karlsson, L.S., Larsson, M.W., Pistol, M.-E., Seifert, W., Trägårdh, J. & Samuelson, L. (2005). Growth and optical properties of strained GaAs−GaxIn1-xP core−shell nanowires. Nano Lett 5(10), 19431947.
Songmuang, R., Landre, O. & Daudin, B. (2007). From nucleation to growth of catalyst-free GaN nanowires on thin AlN buffer layer. Appl Phys Lett 91(25), 251902.
Su, J., Gherasimova, M., Cui, G., Tsukamoto, H., Han, J., Onuma, T., Kurimoto, M., Chichibu, S.F., Broadbridge, C., He, Y. & Nurmikko, A.V. (2005). Growth of AlGaN nanowires by metalorganic chemical vapor deposition. Appl Phys Lett 87(18), 183108.
Thillosen, N., Sebald, K., Hardtdegen, H., Meijers, R., Calarco, R., Montanari, S., Kaluza, N., Gutowski, J. & Lüth, H. (2006). The state of strain in single GaN nanocolumns as derived from micro-photoluminescence measurements. Nano Lett 6(4), 704708.
Ye, H., Yu, Z.Y., Kodambaka, S. & Shenoy, V.B. (2012). Kinetics of axial composition evolution in multi-component alloy nanowires. Appl Phys Lett 100(26), 263103.
Zhang, W., Nikiforov, A.Y., Thomidis, C., Woodward, J., Sun, H., Kao, C.-K., Bhattarai, D., Moldawer, A., Zhou, L., Smith, D.J. & Moustakas, T.D. (2012). Molecular beam epitaxy growth of AlGaN quantum wells on 6H-SiC substrates with high internal quantum efficiency. J Vac Sci Technol B Microelectron Nanometer Struc 30(2), 02B119.



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