| 1. |
- Aberg, I, et al.
(författare)
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Nanoscale tungsten aerosol particles embedded in GaAs
- 2002
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 80:16, s. 2976-2978
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Tidskriftsartikel (refereegranskat)abstract
- GaAs containing buried nanoscale tungsten particles has been characterized electrically. The particles were produced using a special aerosol process and were embedded in GaAs by epitaxial overgrowth. Two different particle sizes were investigated separately. When the particle concentration was increased, a conductance drop of about 500 times was observed. A simulation model, based on a random distribution of the particles, was developed and used to support our findings. The major advantage of our method is the simplicity and low processing cost.
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| 2. |
- 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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| 3. |
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| 4. |
- Lee, S. -K, et al.
(författare)
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Reduction of the barrier height and enhancement of tunneling current of titanium contacts using embedded Au nano-particles on 4H and 6H silicon carbide
- 2002
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Ingår i: Materials Science Forum. - : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. ; 389-393:2, s. 937-940
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the electrical characteristics of Ti Schottky contacts with embedded Au nano-particles on various types of epilayers of SiC (4H- and 6H-SiC). From our current-voltage (I-V) and capacitance-voltage (C-V) measurements, we observed that Ti Schottky contacts with embedded Au nano-particles had 0.19 eV (n-4H-SiC) and 0.15 eV (n-6H-SiC) lower barrier height than those of particle free Ti Schottky contacts. In order to understand this reduction of the Schottky barrier height (SBH) for Ti Schottky contacts with embedded Au nano-particles, it has been proposed that SBH lowering is caused by an enhanced electric field due to the small size of the Au nano-particles and the large SBH difference. We have also tested these contacts on highly doped n-and p-type SiC material to study ohmic contacts using linear TLM measurements.
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| 5. |
- Lee, S. K., et al.
(författare)
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Reduction of the Schottky barrier height on silicon carbide using Au nano-particles
- 2002
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Ingår i: Solid-State Electronics. - 0038-1101 .- 1879-2405. ; 46:9, s. 1433-1440
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Tidskriftsartikel (refereegranskat)abstract
- By the incorporation of size-selected Au nano-particles in Ti Schottky contacts on silicon carbide, we could observe considerably lower the barrier height of the contacts. This result could be obtained for both n- and p-type Schottky contacts using current-voltage and capacitance voltage measurements. For n-type Schottky contacts, we observed reductions of 0.19-0.25 eV on 4H-SiC and 0.15-0.17 eV on 6H-SiC as compared with particle-free Ti Schottky contacts. For p-type SiC, the reduction was a little lower with 0.02-0.05 eV on 4H- and 0.10-0.13 eV on 6H-SiC. The reduction of the Schottky barrier height is explained using a model with enhanced electric field at the interface due to the small size of the circular patch and the large difference of the barrier height between Ti and Au.
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| 6. |
- Mandl, Bernhard, et al.
(författare)
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Self-seeded, position-controlled InAs nanowire growth on Si: A growth parameter study
- 2011
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 334:1, s. 51-56
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the nucleation and growth of InAs nanowires on patterned SiO2/Si(111) substrates is studied. It is found that the nanowire yield is strongly dependent on the size of the etched holes in the SiO2, where openings smaller than 180 nm lead to a substantial decrease in nucleation yield, while openings larger than View the MathML source promote nucleation of crystallites rather than nanowires. We propose that this is a result of indium particle formation prior to nanowire growth, where the size of the indium particles, under constant growth parameters, is strongly influenced by the size of the openings in the SiO2 film. Nanowires overgrowing the etched holes, eventually leading to a merging of neighboring nanowires, shed light into the growth mechanism.
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| 7. |
- Borg, Mattias, et al.
(författare)
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MOVPE Growth and Structural Characterization of Extremely Lattice-Mismatched InP-InSB Nanowire Heterostructures
- 2009
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Ingår i: 2009 IEEE 21st International Conference On Indium Phosphide & Related Materials (IPRM). - 1092-8669. ; , s. 249-252
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Konferensbidrag (refereegranskat)abstract
- We present a growth study and structural characterization of InP-InSb nanowire heterostructures. In contrast to planar epitaxy, this heterostructure can be realized in nanowires without the formation of dislocations, despite an extreme lattice-mismatch (10.4%). We obtain high crystal quality in the InSb nanowires, confirmed by a narrow 111 reflection peak measured by XRD. Additionally, the diameter dependence of the nanowire growth rate was investigated. An original competition between surface growth and nanowire growth is found, which can be controlled by varying the nanowire surface coverage. Finally, HRTEM and X-EDS investigations reveal that the InSb nanowire is always defect-free zinc-blende, and that the InP-InSb heterointerface is free from misfit dislocations, although single twin planes are common.
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| 8. |
- Caroff, Philippe, et al.
(författare)
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InSb heterostructure nanowires: MOVPE growth under extreme lattice mismatch.
- 2009
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 20:49
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Tidskriftsartikel (refereegranskat)abstract
- We demonstrate the growth of InSb-based nanowire heterostructures by metalorganic vapour phase epitaxy and use it to integrate InSb on extremely lattice-mismatched III-V nanowire templates made of InAs, InP, and GaAs. Influence of temperature, V/III ratio, and diameter are investigated in order to investigate the growth rate and morphology. The range of growth temperatures used for InSb nanowire growth is very similar to that used for planar growth due to the nature of the precursor decomposition. This makes optimization of growth parameters very important, and more difficult than for most other nanowire III-V materials. Analysis of the InSb nanowire epitaxial quality when grown on InAs, InP, and GaAs, along with InSb segment and particle compositions are reported. This successful direct integration of InSb nanowires, on nanowire templates with unprecedented strain levels show great promise for fabrication of vertical InSb devices.
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