ERA NANOSCI: Nanowire Arrays for Multifunctional Chemical Sensors
Zusammenfassung der Projektergebnisse
The aim of the present project “Nanowire Arrays for Multifunctional Chemical Sensors (NAWACS)” was to provide the scientific and technological basis for the realization of novel nanowire‐based chemical sensors with pure optical micro‐/nano interfaces by utilizing surface‐related response mechanisms and thus benefiting from the high surface‐to volume ratio of nanowire ensembles. To achieve this goal the growth process of GaN nanowires has been studied in detail and the influence of n‐ and p‐type doping on the growth process as well as on the optical properties has been systematically studied. For the controlled assembly of nanowires to arrays of optically and electrically interacting nano‐objects manipulation by dielectrophoresis has been employed. However, it has been demonstrated that direct analysis of the chemically sensitive photoluminescence properties of group III‐nitride nanowires using an external light source and an external detector (and the photocurrent in metal oxide nanowires as investigated by Partner 2, University of Brescia) yields a controllable micro‐/nano interface that allows the realization of novel chemical sensor systems with improved sensitivity and stability compared to conventional conductometric gas sensors. In addition, optical coupling substantially reduces the number of required electrical feed‐throughs and thus opens up new areas of application in harsh and explosive environments. In such a system, the individual nanowire acts as a device and in order to obtain a good sensor performance the growth process has to be optimized in terms of achieving a high thermal stability of the photoluminescence and a high sensitivity. With this respect the growth of GaN nanodiscs in AlGaN/GaN nanowire heterostructures, giving rise to three‐dimensional confinement, has been investigated and the resulting structural and optical properties of the nanowire heterstructures have been analyzed in detail. Based on these results even more complex growth processes, e.g. for the self assembles growth of GaN quantum wired with diameters below 2 nm could be established. Control of the optical properties of group III‐nitride nanowires by controlled doping or the formation of heterostructures has been proven to be the key requirement for the realization of novel optochemical sensor systems for the application in gases and also in liquids.
Projektbezogene Publikationen (Auswahl)
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“Nucleation and growth of GaN nanorods on Si (111) surfaces by plasma‐assisted molecular beam epitaxy ‐the influence of Si‐ and Mg‐doping”. J. Appl. Phys. 104, 034309 (2008)
F. Furtmayr, M. Vielemeyer, M. Stutzmann, J. Arbiol, S. Estradé, F. Peirò, J. R. Morante, and M. Eickhoff
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„Optical Properties of Si‐and Mg‐Doped Gallium Nitride Nanowires Grown by Plasma Assisted Molecular Beam Epitaxy”. J. Appl. Phys. 104, 074309 (2008)
F. Furtmayr, M. Vielemeyer, M.Stutzmann, and M. Eickhoff
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“Triple‐twin domains in Mg doped GaN wurtzite nanowires: Structural and electronic properties of this zinc‐blende‐like stacking”. Nanotechnology 20, 145704 (2009)
J. Arbiol, S. Estrade, J.D. Prades, A. Cirera, F. Furtmayr, C. Stark, A. Laufer, M. Stutzmann, M. Eickhoff, M.H. Gass, A.L. Bleloch,F. Peiro, J.R. Morante
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“Photoluminescence polarization properties of single GaN nanowires containing AlxGa1−xN/GaN quantum discs”. Phys. Rev. B 81, 045411 (2010)
L. Rigutti, M. Tchernycheva, A. De Luna Bugallo, G. Jacopin, F. H. Julien, F. Furtmayr, M. Stutzmann, M. Eickhoff, R. Songmuang, and F. Fortuna
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“Carrier Confinement in GaN/AlxGa1‐xN Nanowire Heterostructures for 0 < x ≤ 1”. Phys. Rev. B 84, 205303 (2011)
F. Furtmayr, J. Teubert, P. Becker, S. Conesa‐Boj, J. R. Morante, J. Arbiol, and M. Eickhoff
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“GaN nanodiscs embedded in nanowires as optochemical transducers”. Nanotechnology 22, 275505 (2011)
J. Teubert, P. Becker, F. Furtmayr, and M. Eickhoff
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“Opto‐chemical sensor system for the detection of H2 and hydrocarbons based on InGaN/GaN nanowires”. Sensors and Actuators B 173, 120 (2012) 120
S. Paul, A. Helwig, G. Müller, F. Furtmayr, J. Teubert, M. Eickhoff
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“Polarity assignment in ZnTe, GaAs, ZnO and GaN‐AlN nanowires from direct dumbbell analysis”. Nano Letters, 12, 2579 (2012)
M. de la Mata, C. Magen, J. Gazquez, M. I. Bakti Utama, M. Heiss, S. Lopatin, F. Furtmayr, C. J. Fernandez‐Rojas, B. Peng, J. R. Morante, R. Rurali, M. Eickhoff, A. Fontcuberta i Morral, Q. Xiong, J. Arbiol
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“Self‐assembled GaN quantum wires on GaN/AlN nanowire templates”. Nanoscale 4, 7517 (2012)
J. Arbiol, C. Magen, P. Becker, G. Jacopin, A. Chernikov, S. Schäfer, F. Furtmayr, M. Tchernycheva, L. Rigutti, J. Teubert, S. Chatterjee, J. R. Morante and M. Eickhoff
