APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

13 Oct 2003

Volume 83, Issue 15, pp. 2991-3216

Issue Cover Spotlight Figure

Appl. Phys. Lett. 83, 3159 (2003); http://dx.doi.org/10.1063/1.1617378 (3 pages)

Zheng Wei Pan, Sheng Dai, David B. Beach, and Douglas H. Lowndes
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Liquid gallium ball/crystalline silicon polyhedrons/aligned silicon oxide nanowires sandwich structure: An interesting nanowire growth route

Zheng Wei Pan, Sheng Dai, David B. Beach, and Douglas H. Lowndes

Appl. Phys. Lett. 83, 3159 (2003); http://dx.doi.org/10.1063/1.1617378 (3 pages) | Cited 18 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate the growth of silicon oxide nanowires through a sandwich-like configuration, i.e., Ga ball/Si polyhedrons/silicon oxide nanowires, by using Ga as the catalyst and SiO powder as the source material. The sandwich-like structures have a carrot-like morphology, consisting of three materials with different morphologies, states, and crystallographic structures. The “carrot” top is a liquid Ga ball with diameter of ∼ 10–30 μm; the middle part is a Si ring usually composed of about 10 μm-sized, clearly faceted, and crystalline Si polyhedrons that are arranged sequentially in a band around the lower hemisphere surface of the Ga ball; the bottom part is a carrot-shaped bunch of highly aligned silicon oxide nanowires that grow out from the downward facing facets of the Si polyhedrons. This study reveals several interesting nanowire growth phenomena that enrich the conventional vapor-liquid-solid nanowire growth mechanism. © 2003 American Institute of Physics.
Show PACS
81.07.-b Nanoscale materials and structures: fabrication and characterization

Pattern-induced alignment of silicon islands on buried oxide layer of silicon-on-insulator structure

Yasuhiko Ishikawa, Yasuhiro Imai, Hiroya Ikeda, and Michiharu Tabe

Appl. Phys. Lett. 83, 3162 (2003); http://dx.doi.org/10.1063/1.1617370 (3 pages) | Cited 10 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Alignment control of Si islands thermally agglomerated on a buried SiO2 layer of a silicon-on-insulator (SOI) structure is reported. As a starting structure, a line-shaped (001) SOI layer is prepared using an electron beam lithography and a selective oxidation technique. Annealing in an ultrahigh vacuum, SOI line structure having submicron width and thickness of ∼3 nm is deformed into island arrays aligned along two edges of the line pattern. This pattern-induced alignment occurs independent of in-plane crystalline directions of the line pattern, while we have previously reported for unpatterned SOI that the island alignment is commonly observed along the 〈310〉 directions. It is indicated that the linewidth and the SOI thickness play key roles in changing alignment behavior from the crystalline directions to the line pattern directions. © 2003 American Institute of Physics.
Show PACS
85.40.Hp Lithography, masks and pattern transfer
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
61.72.Cc Kinetics of defect formation and annealing
81.65.Mq Oxidation

Temperature and strain rate effects on the strength and ductility of nanostructured copper

Y. M. Wang and E. Ma

Appl. Phys. Lett. 83, 3165 (2003); http://dx.doi.org/10.1063/1.1618370 (3 pages) | Cited 75 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We show that the yield strength for Cu with ultrafine grain sizes becomes obviously temperature and strain-rate dependent, in contrast to the temperature/rate insensitive behavior of conventional face-centered-cubic metals. A thermally activated deformation mechanism is operative at room temperature and especially at slow strain rates, but not at 77 K. In addition to the gain in strength, the tensile ductility and particularly uniform strains also increase at cryogenic temperatures and with increasing strain rate, as a result of improved strain hardening due to suppressed dynamic recovery. © 2003 American Institute of Physics.
Show PACS
81.40.Lm Deformation, plasticity, and creep
62.25.-g Mechanical properties of nanoscale systems
62.20.F- Deformation and plasticity
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization

Electrical properties of zinc oxide nanowires and intramolecular p–n junctions

C. H. Liu, W. C. Yiu, F. C. K. Au, J. X. Ding, C. S. Lee, and S. T. Lee

Appl. Phys. Lett. 83, 3168 (2003); http://dx.doi.org/10.1063/1.1609232 (3 pages) | Cited 73 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electrical properties of ZnO nanowires and intramolecular p–n junctions were characterized by I–V measurements. These nanowires were grown embedded in anodic aluminum oxide (AAO) templates by vapor-phase-transport growth method. The nanowires were dense, continuous, and uniform in diameter along the length of the wires. I–V measurements showed the average resistivity of the ZnO nanowires in AAO templates was about one order of magnitude higher than that of the naked single ZnO nanowire. The p–n junctions in ZnO nanowires were fabricated by a two-step growth of ZnO with and without dopant of boron ( ∼ 1 wt %) in the source. I–V results suggested that p–n junctions in ZnO nanowires were formed by the two-step method. © 2003 American Institute of Physics.
Show PACS
73.63.Nm Quantum wires
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
68.65.La Quantum wires (patterned in quantum wells)
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)

Determination of the electric field in 4H/3C/4H-SiC quantum wells due to spontaneous polarization in the 4H SiC matrix

S. Bai, R. P. Devaty, W. J. Choyke, U. Kaiser, G. Wagner, and M. F. MacMillan

Appl. Phys. Lett. 83, 3171 (2003); http://dx.doi.org/10.1063/1.1618020 (3 pages) | Cited 27 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report a low-temperature photoluminescence study of 4H/3C/4H-SiC single quantum wells. A quantum well consists of thirteen 3C-SiC bilayers as displayed in a high-resolution transmission electron microscope image. The optical emission energy of the quantum well is more than 200 meV below the exciton band gap of bulk 3C-SiC. A strong internal electric field on the order of 1 MV/cm leads to the large redshift of the emission energy due to the quantum-confined Stark effect. The origin of this field is discussed in terms of the spontaneous polarization difference between 3C- and 4H-SiC. © 2003 American Institute of Physics.
Show PACS
78.67.De Quantum wells
73.21.Fg Quantum wells
78.55.Hx Other solid inorganic materials
78.20.Jq Electro-optical effects

Critical pressure for weakening of size-induced stiffness in spinel-structure Si3N4 nanocrystals

Zhongwu Wang, Yusheng Zhao, David Schiferl, C. S. Zha, Robert T. Downs, and T. Sekine

Appl. Phys. Lett. 83, 3174 (2003); http://dx.doi.org/10.1063/1.1618365 (3 pages) | Cited 13 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate that the compressibility of spinel Si3N4 nanocrystals increases when the pressure is raised above ∼40 GPa. Si3N4 nanocrystals initially exhibit an extremely high bulk modulus of 685(45) GPa. But, above 40 GPa, the bulk modulus is reduced to 415(10) GPa. Thus, a critical pressure of ∼40 GPa was determined that signifies the onset of size-induced weakening of elastic stiffness in nanocrystalline Si3N4. Enhanced surface energy contributions to the shell layers of nanoparticles and the resulting effect on the corresponding large d-spacing planes are used to explain the observed phenomenon. Upon decompression, the bulk modulus of the Si3N4 spinel remained at its lower value of 415 GPa. This study provides a reasonable explanation for the different compressibility properties of numerous nanocrystals. © 2003 American Institute of Physics.
Show PACS
62.20.F- Deformation and plasticity
81.40.Lm Deformation, plasticity, and creep
61.46.-w Structure of nanoscale materials
62.20.D- Elasticity
81.07.Bc Nanocrystalline materials
62.50.-p High-pressure effects in solids and liquids
81.40.Jj Elasticity and anelasticity, stress-strain relations
81.07.Wx Nanopowders

Thermal oxidation of gallium nitride nanowires

Chengchun Tang, Yoshio Bando, and Zongwen Liu

Appl. Phys. Lett. 83, 3177 (2003); http://dx.doi.org/10.1063/1.1618943 (3 pages) | Cited 10 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The thermal oxidation of gallium nitride (GaN) nanowires in dry air was investigated by using thermogravimetric and transmission electron microscopy. The oxidation strongly depends on the oxidation temperature and the nanowire diameters. At temperatures lower than 700 °C, the oxidation is dominantly controlled by an oxygen absorption reaction. A chemical oxidation reaction occurs upon further increasing the temperature, accompanied by the formation of monoclinic gallium oxide (Ga2O3). The crystalline Ga2O3 can form a dense protective shell on the surfaces of GaN nanowires with large diameters, whereas Ga2O3 could not crystallize into one-dimensional morphology on the initial GaN nanowires with small diameters. © 2003 American Institute of Physics.
Show PACS
68.65.La Quantum wires (patterned in quantum wells)
81.65.Mq Oxidation
68.37.Lp Transmission electron microscopy (TEM)

Electronic structure of the contact between carbon nanotube and metal electrodes

S. Dag, O. Gülseren, S. Ciraci, and T. Yildirim

Appl. Phys. Lett. 83, 3180 (2003); http://dx.doi.org/10.1063/1.1616662 (3 pages) | Cited 31 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Our first-principles study of the contact between a semiconducting single-walled carbon nanotube (s-SWNT) and metal electrodes shows that the electronic structure and potential depend strongly on the type of metal. The s-SWNT is weakly side-bonded to the gold surface with minute charge rearrangement and remains semiconducting. A finite potential barrier forms at the contact region. In contrast, the molybdenum surface forms strong bonds, resulting in significant charge transfer and metallicity at the contact. The radial deformation of the tube lowers the potential barrier at the contact and increases the state density at the Fermi level. © 2003 American Institute of Physics.
Show PACS
73.22.-f Electronic structure of nanoscale materials and related systems
73.40.Ns Metal-nonmetal contacts
71.15.-m Methods of electronic structure calculations

Growth of uniform InAs quantum dots on InGaAs surface structure modified superlattices on InP

Z. H. Zhang and K. Y. Cheng

Appl. Phys. Lett. 83, 3183 (2003); http://dx.doi.org/10.1063/1.1618372 (3 pages) | Cited 6 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have developed a matrix layer structure, the InGaAs surface structure modified superlattice, to achieve high quality InAs quantum dots on (100) InP substrates. Formed by periodically repeating the group III- and group V-stabilized InGaAs layers, the InGaAs surface structure modified superlattice offers much greater advantages than the conventional InGaAs matrix layer for the growth of InAs quantum dots, where a thick InAs layer is required for the dot formation. By adjusting the number of period and the layer thickness of the superlattice structure, uniform InAs quantum dots are achieved even using an InAs deposition as thin as 2.5 monolayers. Photoluminescence measurements further verify a uniform size distribution of the achieved quantum dots. © 2003 American Institute of Physics.
Show PACS
68.65.Hb Quantum dots (patterned in quantum wells)
81.07.Ta Quantum dots
68.65.Cd Superlattices
78.67.Hc Quantum dots
78.67.Pt Multilayers; superlattices; photonic structures; metamaterials
78.55.Cr III-V semiconductors

Thermal conductivity of Si/SiGe superlattice nanowires

Deyu Li, Yiying Wu, Rong Fan, Peidong Yang, and Arun Majumdar

Appl. Phys. Lett. 83, 3186 (2003); http://dx.doi.org/10.1063/1.1619221 (3 pages) | Cited 106 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The thermal conductivities of individual single crystalline Si/SiGe superlattice nanowires with diameters of 58 and 83 nm were measured over a temperature range from 20 to 320 K. The observed thermal conductivity shows similar temperature dependence as that of two-dimensional Si/SiGe superlattice films. Comparison with the thermal conductivity data of intrinsic Si nanowires suggests that alloy scattering of phonons in the Si–Ge segments is the dominant scattering mechanism in these superlattice nanowires. In addition, boundary scattering also contributes to thermal conductivity reduction. © 2003 American Institute of Physics.
Show PACS
68.65.Cd Superlattices
66.70.-f Nonelectronic thermal conduction and heat-pulse propagation in solids; thermal waves
63.22.-m Phonons or vibrational states in low-dimensional structures and nanoscale materials

Crystallographic influence on nanomechanics of (100)-oriented silicon resonators

Dong F. Wang, Takahito Ono, and Masayoshi Esashi

Appl. Phys. Lett. 83, 3189 (2003); http://dx.doi.org/10.1063/1.1616652 (3 pages) | Cited 4 times

Online Publication Date: 7 October 2003

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The influence of crystallographic orientation on the nanomechanical properties of 50 nm thick (100)-oriented single-crystal silicon resonators was investigated by examining the effects of surface treatments, such as flash-heating, on the mechanical quality factors (Q-factors) and resonant frequencies. The measured Q-factors were found to vary periodically with crystallographic orientation and were shown to have higher values in the 〈110〉 direction. A 1500 nm thick (100)-oriented cantilever array was also studied for comparison, for which no obvious periodic change was observed. Since the energy dissipation in vibrating resonators cannot be explained by the support loss or thermoelastic loss, a surface-related mechanism should be considered. © 2003 American Institute of Physics.
Show PACS
85.85.+j Micro- and nano-electromechanical systems (MEMS/NEMS) and devices
81.65.-b Surface treatments
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close