| 1. |
- Borg, Mattias, et al.
(författare)
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GaAs/GaSb nanowire heterostructures grown by MOVPE
- 2008
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 310:18, s. 4115-4121
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Tidskriftsartikel (refereegranskat)abstract
- We report Au-assisted growth of GaAs/GaSb nanowire heterostructures on GaAs(1 1 1)B-substrates by metal-organic vapor phase epitaxy. The growth is studied at various precursor molar fractions and temperatures, in order to optimize the growth conditions for the GaSb nanowire segment. In contrast to most other III-V nanowire systems, the GaSb nanowire growth is Group V-limited under most conditions. We found that depending on the TMSb molar fraction, the seed particle is either supersaturated AuGa or AuGa2 during GaSb growth. The high Ga content in the particle gives a characteristic diameter increase between the GaAs and GaSb segment. From TEM and XEDS measurements we conclude that the GaSb nanowire growth occurs along either the AuGa-GaSb or AuGa2-GaSb pseudo-binaries of the Au-Ga-Sb ternary phase diagram. Finally, the GaSb nanowires exhibit untapered radial growth on the {1 (1) over bar 0} side facets. (C) 2008 Elsevier B.V. All rights reserved.
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| 2. |
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| 3. |
- Nilsson, Henrik, et al.
(författare)
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Giant, level-dependent g factors in InSb nanowire quantum dots.
- 2009
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 9:9, s. 3151-3156
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Tidskriftsartikel (refereegranskat)abstract
- We report on magnetotransport measurements on InSb nanowire quantum dots. The measurements show that the quantum levels of the InSb quantum dots have giant g factors, with absolute values up to approximately 70, the largest value ever reported for semiconductor quantum dots. We also observe that the values of these g factors are quantum level dependent and can differ strongly between different quantum levels. The presence of giant g factors indicates that considerable contributions from the orbital motion of electrons are preserved in the measured InSb nanowire quantum dots, while the level-to-level fluctuations arise from spin-orbit interaction. We have deduced a value of Delta(SO) = 280 mueV for the strength of spin-orbit interaction from an avoided level crossing between the ground state and first excited state of an InSb nanowire quantum dot with a fixed number of electrons.
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| 4. |
- Pettersson, Håkan, 1962-, et al.
(författare)
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Nano-Schottky contacts realized by bottom-up technique
- 2010
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Ingår i: Bulletin of American Physical Society. - : American Physical Society.
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Konferensbidrag (refereegranskat)abstract
- Here we present a comprehensive study of a rectifying nano-Schottky contact formed at the interface between a gold catalytic particle and an epitaxially grown GaInAs/InAs nanowire. Selective electrical connections formed by electron beam lithography to the catalytic particle on one side, and to the InAs segment on the other side allowed electrical and optical characterization of the formed Schottky junction. From IV measurements taken at different temperatures we have deduced the Schottky barrier height and the height of the barrier formed in the graded GaInAs nanowire segment. The IV characteristics measured under laser stimulation showed that the device can be used as a unipolar photodetector with extremely small detection volume and potentially ultra fast response.
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| 5. |
- Roddaro, Stefano, et al.
(författare)
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Growth of vertical InAs nanowires on heterostructured substrates
- 2009
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 20:28
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the Au-assisted growth of InAs nanowires on two different kinds of heterostructured substrates: GaAs/AlGaAs structures capped by a 50 nm thick InAs layer grown by molecular beam epitaxy and a 2 mu m thick InAs buffer layer on Si(111) obtained by vapor phase epitaxy. Morphological and structural properties of substrates and nanowires are analyzed by atomic force and transmission electron microscopy. Our results indicate a promising direction for the integration of III-V nanostructures on Si-based electronics as well as for the development of novel micromechanical structures incorporating nanowires as their active elements.
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| 6. |
- Suyatin, Dmitry, et al.
(författare)
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Nano-Schottky contacts realized by bottom-up technique
- 2010
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Ingår i: INEC 2010 - 2010 3rd International Nanoelectronics Conference, Proceedings. - Piscataway, N.J. : IEEE Press. - 9781424435432 ; , s. 252-253
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Konferensbidrag (refereegranskat)abstract
- Properties of nanostructures realized by bottom-up techniques are often different from their bulk counterparts. Here we present a study of a nano-Schottky contact formed at the interface between a gold catalytic particle and an epitaxially grown GaxIn1-xAs/InAs nanowire. Selective electrical connections formed to the catalytic particle on one side and to the InAs segment on the other side allowed electrical and optical characterization of the formed junction. We demonstrate that the heterostructure region adjacent to the catalytic particle may act as an ultra-small volume unipolar photodetector with potentially ultra-fast response.
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| 7. |
- Bao, Jiming, et al.
(författare)
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Optical properties of rotationally twinned InP nanowire heterostructures
- 2008
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 8:3, s. 836-841
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Tidskriftsartikel (refereegranskat)abstract
- We have developed a technique so that both transmission electron microscopy and microphotoluminescence can be performed on the same semiconductor nanowire over a large range of optical power, thus allowing us to directly correlate structural and optical properties of rotationally twinned zinc blende InP nanowires. We have constructed the energy band diagram of the resulting multiquantum well heterostructure and have performed detailed quantum mechanical calculations of the electron and hole wave functions. The excitation power dependent blue-shift of the photoluminescence can be explained in terms of the predicted staggered band alignment of the rotationally twinned zinc blende/wurzite InP heterostructure and of the concomitant diagonal transitions between localized electron and hole states responsible for radiative recombination. The ability of rotational twinning to introduce a heterostructure in a chemically homogeneous nanowire material and alter in a major way its optical properties opens new possibilities for band-structure engineering.
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| 8. |
- Berg, Alexander, et al.
(författare)
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Radial Nanowire Light-Emitting Diodes in the (AlxGa1-x)yIn1-yP Material System
- 2016
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Ingår i: Nano letters (Print). - Washington, DC : American Chemical Society (ACS). - 1530-6984 .- 1530-6992. ; 16:1, s. 656-662
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Tidskriftsartikel (refereegranskat)abstract
- Nanowires have the potential to play an important role for next-generation light-emitting diodes. In this work, we present a growth scheme for radial nanowire quantum-well structures in the AlGaInP material system using a GaInP nanowire core as a template for radial growth with GaInP as the active layer for emission and AlGaInP as charge carrier barriers. The different layers were analyzed by X-ray diffraction to ensure lattice-matched radial structures. Furthermore, we evaluated the material composition and heterojunction interface sharpness by scanning transmission electron microscopy energy dispersive X-ray spectroscopy. The electro-optical properties were investigated by injection luminescence measurements. The presented results can be a valuable track toward radial nanowire light-emitting diodes in the AlGaInP material system in the red/orange/yellow color spectrum. © 2015 American Chemical Society.
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| 9. |
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| 10. |
- Fröberg, Linus, et al.
(författare)
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Transients in the Formation of Nanowire Heterostructures.
- 2008
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 8:11, s. 3815-3818
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Tidskriftsartikel (refereegranskat)abstract
- We present results on the effect of seed particle reconfiguration on the growth of short InAs and InP nanowire segments. The reconfiguration originates in two different steady state alloy compositions of the Au/In seed particle during growth of InAs and InP. From compositional analysis of the seed particle, the In content in the seed particle is determined to be 34 and 44% during InAs and InP growth, respectively. When switching between growing InAs and InP, transient effects dominate during the time period of seed particle reconfiguration. We developed a model that quantitatively explains the effect and with the added understanding we are now able to grow short period (<10 nm) nanowire superlattices.
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