| 1. |
- Deppert, Knut, et al.
(författare)
-
Epitaxielle Kristallnadeln und -bäume
- 2005
-
Ingår i: Book of abstracts: DGKK-Jahrestagung, Köln, Germany (2005).
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Dick Thelander, Kimberly, et al.
(författare)
-
Improving InAs nanotree growth with composition-controlled Au-In nanoparticles
- 2006
-
Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 17:5, s. 1344-1350
-
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.
|
|
| 5. |
- Fröberg, Linus, et al.
(författare)
-
Transients in the Formation of Nanowire Heterostructures.
- 2008
-
Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 8:11, s. 3815-3818
-
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.
|
|
| 6. |
- Johansson, Jonas, et al.
(författare)
-
Effects of growth conditions on the crystal structure of gold-seeded GaP nanowires
- 2008
-
Ingår i: Journal of Chrystal Growth. - : Elsevier BV. - 0022-0248. ; 310:23, s. 5102-5105
-
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.
|
|
| 7. |
- Johansson, Jonas, et al.
(författare)
-
Effects of Supersaturation on the Crystal Structure of Gold Seeded III-V Nanowires
- 2009
-
Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 9:2, s. 766-773
-
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.
|
|
| 8. |
- Johansson, Jonas, et al.
(författare)
-
Structural properties of (111)B-oriented III-V nanowires
- 2006
-
Ingår i: Nature Materials. - : Springer Science and Business Media LLC. - 1476-4660 .- 1476-1122. ; 5:7, s. 574-580
-
Tidskriftsartikel (refereegranskat)abstract
- Controlled growth of nanowires is an important, emerging research field with many applications in, for example, electronics, photonics, and life sciences. Nanowires of zinc blende crystal structure, grown in the left fence111right fenceB direction, which is the favoured direction of growth, usually have a large number of twin-plane defects. Such defects limit the performance of optoelectronic nanowire-based devices. To investigate this defect formation, we examine GaP nanowires grown by metal-organic vapour-phase epitaxy. We show that the nanowire segments between the twin planes are of octahedral shape and are terminated by {111} facets, resulting in a microfaceting of the nanowires. We discuss these findings in a nucleation context, where we present an idea on how the twin planes form. This investigation contributes to the understanding of defect formation in nanowires. One future prospect of such knowledge is to determine strategies on how to control the crystallinity of nanowires.
|
|
| 9. |
- Johansson, Jonas, et al.
(författare)
-
The structure of <1 1 1 > B oriented GaP nanowires
- 2007
-
Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 298, s. 635-639
-
Tidskriftsartikel (refereegranskat)abstract
- Nanowires of zinc blende crystal structure, grown in the < 111 > B direction usually have a large number of twin plane defects. In order to investigate this phenomenon, we grow GaP nanowires with metal-organic vapor phase epitaxy. By rotating the nanowires in a high resolution transmission electron microscope, we show that the nanowire segments between the twin planes are of octahedral shape and are terminated by {111} facets. Due to the alternating orientations of these twin octahedra, the sidewalls of the nanowires can be described as microfaceted surfaces with an overall orientation of 11 1 2}, but composed of alternating 11 1 I}A and {1 I 1}B facets. Moreover, the segment thicknesses follow exponential distributions, which show that there is a certain probability of twin plane formation, which is independent of segment thickness. (c) 2006 Elsevier B.V. All rights reserved.
|
|
| 10. |
|
|
