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| 2. |
- Dick Thelander, Kimberly, et al.
(författare)
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A new understanding of au-assisted growth of III-V semiconductor nanowires
- 2005
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 15:10, s. 1603-1610
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Tidskriftsartikel (refereegranskat)abstract
- Semiconductor nanowires of III-V materials have generated much interest in recent years. However, the growth mechanisms by which these structures form are not well understood. The so-called vapor-liquid-solid (VLS) mechanism has often been proposed for III-V systems, with a chemically inert, liquid metal particle (typically Au) acting as a physical catalyst. We assert here that An is, in fact, not inert with respect to the semiconductor material but rather interacts with it to form a variety of intermetallic compounds. Moreover, we suggest that III-V nanowire growth can best be understood if the metallic particle is not a liquid, but a solid-phase solution or compound containing An and the group III material. The four materials GaP, GaAs, InP, and InAs will be considered, and growth behavior related to their particular temperature-dependent interaction with Au.
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| 3. |
- Dick Thelander, Kimberly, et al.
(författare)
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Directed growth of branched nanowire structures
- 2007
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Ingår i: MRS Bulletin. - 1938-1425. ; 32:2, s. 127-133
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Tidskriftsartikel (refereegranskat)abstract
- We describe the production of hierarchical branched nanowire structures by the sequential seeding of multiple wire generations with metal nanoparticles. Such complex structures represent the next step in the study of functional nanowires, as they increase the potential functionality of nanostructures produced in a self-assembled way. It is possible, for example, to fabricate a variety of active heterostructure segments with different compositions and diameters within a single connected structure. The focus of this work is on epitaxial III-V semiconductor branched nanowire structures, with the two materials GaP and InAs used as typical examples of branched structures with cubic (zinc blende) and hexagonal (wurtzite) crystal structures. The general morphology of these structures will be described, as well as the relationship between morphology and crystal structure.
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| 4. |
- Dick Thelander, Kimberly, et al.
(författare)
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Improving InAs nanotree growth with composition-controlled Au-In nanoparticles
- 2006
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 17:5, s. 1344-1350
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Tidskriftsartikel (refereegranskat)abstract
- Au nanoparticles are commonly used as seeds for epitaxial growth of III-V semiconductor nanowires. However, the interaction between Au and In-containing III-V materials makes it difficult to control the growth of more complex nanowire structures in materials such as InAs. Here we report the growth of InAs nanowires and branched nanotrees using Au and Au-In nanoparticles. We show that the initial composition of the particle does not affect the morphology of the first-generation nanowires, nor does it affect the final composition of the particle after growth. However, when the Au-In particles were used to seed a second generation of nanowires, producing nanotrees, the branches exhibited a 2-3 times higher growth rate and more regular shape than those seeded by pure Au particles. This result is attributed to the decreased interaction between the seed particle and the trunk nanowires when Au-In particles are used. Thus the incorporation of In into the seed particle during particle production allows for modification of the particle-wire interaction.
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| 5. |
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| 6. |
- Dick Thelander, Kimberly, et al.
(författare)
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Position-controlled interconnected InAs nanowire networks
- 2006
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 6:12, s. 2842-2847
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate here a method for controlled production of complex self-assembled three-dimensional networks of InAs nanowires on a substrate, based on sequentially seeded epitaxial nanowire structures, or "nanotrees". A position-controlled array of trunk nanowires is first produced using lithographically defined Au particles as seeds. With these wires positioned along the proper crystallographic directions with respect to each other, nanotree branches grow toward neighboring trunks, connecting them together. Finally, we investigate the crystal structure of the interconnected nanotrees, demonstrating that branch growth after the contact with the second trunk has an epitaxial relationship to that trunk.
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| 7. |
- Dick Thelander, Kimberly, et al.
(författare)
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Role of the Au/III-V interaction in the Au-assisted growth of III-V branched nanostructures
- 2005
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Ingår i: 2005 International Conference on Indium Phosphide and Related Materials (IEEE Cat. No. 05CH37633). - 0780388917 ; , s. 487-490
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Konferensbidrag (refereegranskat)abstract
- The growth behaviour of Au-catalyzed III-V semiconductor nanowires and nanotrees is strongly affected by the temperature dependent interaction between the catalytic Au particle and the particular III-V material
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| 8. |
- Dick Thelander, Kimberly, et al.
(författare)
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Self-assembled InAs nanowire networks
- 2005
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Ingår i: Book of extended abstracts: MRS Fall Meet, Boston, Ma, USA, 2005.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 9. |
- Johansson, Jonas, et al.
(författare)
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Effects of growth conditions on the crystal structure of gold-seeded GaP nanowires
- 2008
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Ingår i: Journal of Chrystal Growth. - : Elsevier BV. - 0022-0248. ; 310:23, s. 5102-5105
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Konferensbidrag (refereegranskat)abstract
- we present results that provide fundamental insights on how to experimentally tailor the planar defect density and even the crystal structure in III-V metal-particle-seeded nanowires, where zinc blende is the stable bulk crystal structure. We have grown GaP nanowires with metal-organic vapor-phase epitaxy under different conditions: pulsing of the Ga source, and Continuous growth with and without In background. The dominant crystal structure of the nanowires is zinc blende, which when grown under continuous conditions has a high density of twin planes perpendicular to the growth direction. Using pulsed growth we observed that the twin plane separations were much longer than those observed for continuous growth with an In background. On the other hand, during continuous growth, under In-free conditions, a considerable amount of the wurtzite-phase forms. Our results suggest that it might be possible to predict the conditions necessary for the growth of wires with perfect crystal structure. We interpret our results in terms of the supersaturation during growth. (C) 2008 Elsevier B.V. All rights reserved.
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| 10. |
- Johansson, Jonas, et al.
(författare)
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Effects of Supersaturation on the Crystal Structure of Gold Seeded III-V Nanowires
- 2009
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 9:2, s. 766-773
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Tidskriftsartikel (refereegranskat)abstract
- We present results that provide fundamental insights on how to experimentally tailor the planar defect density and even the crystal structure in III-V metal particle seeded nanowires, where zinc blende is the stable bulk crystal structure. We have grown GaP nanowires with metal-organic vapor phase epitaxy under different conditions: pulsing of the Ga source, and continuous growth with and without In background. The dominant crystal structure of the nanowires is zinc blende, which when grown under continuous conditions has a high density of twin planes perpendicular to the growth direction. Using pulsed growth, we observed that the twin plane separations were much longer than those observed for continuous growth with an In background. On the other hand, during continuous growth, under In-free conditions, a considerable amount of the wurtzite phase forms. We explain the importance of the In background during growth. With classical nucleation modeling we qualitatively relate the density of planar defects in a nanowire to the growth conditions. For low supersaturations, we predict a low twin plane density, consistent with our experimental observations of pulsed nanowire growth. In addition, we suggest that under certain conditions, it might be possible to grow wires with almost perfect wurtzite structure.
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