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

7 May 2007

Volume 90, Issue 19, Articles (19xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 90, 193501 (2007); http://dx.doi.org/10.1063/1.2737344 (3 pages)

Peter Modregger, Daniel Lübbert, Peter Schäfer, and Rolf Köhler
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Direct writing of molecularly imprinted microstructures using a nanofountain pen

Anne-Sophie Belmont, Mordechai Sokuler, Karsten Haupt, and Levi A. Gheber

Appl. Phys. Lett. 90, 193101 (2007); http://dx.doi.org/10.1063/1.2730753 (3 pages) | Cited 5 times

Online Publication Date: 7 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Molecularly imprinted polymers (MIPs) constitute a very appealing avenue to parallel sensors of a multitude of small target molecules due to their stability, relative ease of preparation, and their ability to recognize targets for which natural capture molecules do not exist. The authors present here a way of arraying MIP structures with micrometer dimensions, using nanofountain pen, and demonstrate their functionality using a fluorescent template molecule.
Show PACS
81.16.-c Methods of micro- and nanofabrication and processing
61.41.+e Polymers, elastomers, and plastics
78.55.Kz Solid organic materials

Ag nanoshell-induced dual-frequency electromagnetic wave absorption of Ni nanoparticles

Chung-Che Lee and Dong-Hwang Chen

Appl. Phys. Lett. 90, 193102 (2007); http://dx.doi.org/10.1063/1.2731706 (3 pages) | Cited 36 times

Online Publication Date: 7 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The electromagnetic wave absorption properties of the epoxy resin composites containing Ni, Ag, and Ni–Ag core-shell nanoparticles were studied. Interestingly, Ni–Ag core-shell nanoparticles showed a dual-frequency absorption property in 2–18 and 18–40 GHz, although Ni nanoparticles exhibited absorption only in 18–40 GHz and no absorption was observed for Ag nanoparticles in the whole frequency range. The additional absorption of Ni–Ag core-shell nanoparticles in 2–18 GHz might be due to the lags of polarization between the core/shell interfaces, which contributed to the dielectric loss. The frequency dependences of permittivity and permeability and the absorber thickness effect were also investigated.
Show PACS
78.70.Gq Microwave and radio-frequency interactions
77.84.Lf Composite materials
77.22.Gm Dielectric loss and relaxation
77.22.Ej Polarization and depolarization
77.22.Ch Permittivity (dielectric function)

Temperature dependence of the surface plasmon coupling with an InGaN/GaN quantum well

Yen-Cheng Lu, Cheng-Yen Chen, Dong-Ming Yeh, Chi-Feng Huang, Tsung-Yi Tang, Jeng-Jie Huang, and C. C. Yang

Appl. Phys. Lett. 90, 193103 (2007); http://dx.doi.org/10.1063/1.2738194 (3 pages) | Cited 22 times

Online Publication Date: 7 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors demonstrate the temperature-dependent behavior of the surface plasmon (SP) coupling with two InGaN/GaN quantum-well (QW) structures of different internal quantum efficiencies. The SP modes are generated at the interface between the QW structures and Ag thin films coated on their tops. It is observed that the SP-QW coupling rate increases with temperature. Such a trend may rely on several factors, including the availability of carriers with sufficient momenta for transferring the energy and momentum into the SP modes and possibly the variation of the SP density of state with temperature. Although the required momentum matching condition only needs the thermal energy corresponding to a few tens of Kelvins, the carrier delocalization process results in a significantly higher probability of SP-carrier momentum matching and hence SP-QW coupling.
Show PACS
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
73.21.Fg Quantum wells

Defect-induced electrical conductivity increase in individual multiwalled carbon nanotubes

S. Agrawal, M. S. Raghuveer, H. Li, and G. Ramanath

Appl. Phys. Lett. 90, 193104 (2007); http://dx.doi.org/10.1063/1.2737127 (3 pages) | Cited 16 times

Online Publication Date: 7 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors demonstrate that ozone exposure of individual multiwalled carbon nanotubes (CNTs) results in up to threefold increase in CNT conductivity and 50% decrease in carrier transport activation energy. Ozone exposure induces bond breaking in the individual shells and promotes cross-shell bridging via sp3 bond formation. Intershell bridging facilitates charge carrier hopping to inner shells, which can serve as additional charge carrier transport pathways, offsetting the effect of defect-scattering-induced conductivity decrease. The CNT etch rate systematically increases with decreasing initial outer diameter and decreases with incremental ozone exposure, which could provide means to controllably tailor the CNT conductance. The results suggest that controlled defect creation could be an attractive strategy to induce electrical conductivity increase in multiwalled CNTs for use in nanodevice wiring and related applications.
Show PACS
73.63.Fg Nanotubes
61.46.Fg Nanotubes
72.20.Ee Mobility edges; hopping transport
81.07.De Nanotubes
81.65.Cf Surface cleaning, etching, patterning

Catalytic chemiluminescence properties of boehmite “nanococoons”

Huaqiang Cao, Lei Zhang, Xiangwen Liu, Sichun Zhang, Yu Liang, and Xinrong Zhang

Appl. Phys. Lett. 90, 193105 (2007); http://dx.doi.org/10.1063/1.2737133 (3 pages) | Cited 3 times

Online Publication Date: 7 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
There have been great interest in constructing advanced nanostructures due to the potential profit of achieving nanodevices with interesting properties; much effort has been devoted to combining biology and nanotechnology to synthesize superstructures, in shapes of higher complexity than those of low-dimensional nanostructures. The advanced nanostructures can function from sensing to emitting light or storing information. Here the authors demonstrate the self-organization of boehmite nanorods into the cocoonlike nanostructures by using glycine as reactant. The growth mechanism is described. The boehmite (γ-AlOOH) nanococoons exhibit excellent sensitivity to ethanol vapor with rapid, stable, and reversible characteristics as catalytic chemiluminescence nanosensors.
Show PACS
81.07.Bc Nanocrystalline materials
82.40.-g Chemical kinetics and reactions: special regimes and techniques
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
81.16.Dn Self-assembly
07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
82.80.-d Chemical analysis and related physical methods of analysis

Efficient coupling of photonic crystal microcavity modes to a ridge waveguide

M. G. Banaee, A. G. Pattantyus-Abraham, M. W. McCutcheon, G. W. Rieger, and Jeff F. Young

Appl. Phys. Lett. 90, 193106 (2007); http://dx.doi.org/10.1063/1.2737369 (3 pages) | Cited 13 times

Online Publication Date: 7 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The unidirectional coupling of a microcavity mode to a ridge waveguide in a slab photonic crystal structure was investigated for the first time. Experimental observation of the coupling efficiency for the signal coupled out of the structure is in good agreement with the result of three-dimensional finite-difference time-domain simulations. The coupling efficiency of the cavity mode to the output channel is ∼ 60%.
Show PACS
42.79.Gn Optical waveguides and couplers
42.70.Qs Photonic bandgap materials

Design of molecular wires based on one-dimensional coordination polymers

Simone S. Alexandre, José M. Soler, Pablo J. Sanz Miguel, R. W. Nunes, Félix Yndurain, Júlio Gómez-Herrero, and Félix Zamora

Appl. Phys. Lett. 90, 193107 (2007); http://dx.doi.org/10.1063/1.2737371 (3 pages) | Cited 10 times

Online Publication Date: 7 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors report the results of ab initio calculations for the structural and electronic properties of one-dimensional coordination polymers with the general formula [M(6-MP)2]n (where 6-MP = 6-mercaptopurinate, and M = MnII, FeII, CoII, NiII, and CuII). A common stable structure, consistent with the experimental data for [Cd(6-MP)2]n, is found for all metal cations studied, with the exception of MnII. Polymers containing FeII, NiII, and CoII are found to be ferromagnetic semiconductors, while [Cu(6-MP)2]n shows a Peierls-unstable paramagnetic metallic phase that undergoes a transition to a ferromagnetic semiconductor one under small stretching.
Show PACS
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
75.50.Dd Nonmetallic ferromagnetic materials
75.20.Ck Nonmetals
75.50.Pp Magnetic semiconductors

Superhydrophobic spiral Co3O4 nanorod arrays

Zhi-guang Guo and Wei-min Liu

Appl. Phys. Lett. 90, 193108 (2007); http://dx.doi.org/10.1063/1.2737388 (3 pages) | Cited 19 times

Online Publication Date: 7 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors report a facile method for the fabrication of a superhydrophobic surface with spiral Co3O4 nanorod arrays on a glass wafer plated Au. The resulting surface shows superhydrophobicity with a static contact angle of about (162±1.6)° and a sliding angle of around (5±2)°. This functionalized, nanostructured surface provides enhanced understanding of the effect of the surface roughness and solid surface fraction on superhydrophobicity, rendering them well suited for various potential applications such as in catalysts, dyes or inks, coatings, fillers, and microreactors.
Show PACS
68.47.Gh Oxide surfaces
61.46.Hk Nanocrystals
68.08.-p Liquid-solid interfaces
81.07.-b Nanoscale materials and structures: fabrication and characterization

Plasmon excitations in scanning tunneling microscopy: Simultaneous imaging of modes with different localizations coupled at the tip

Manuel J. Romero, Jao van de Lagemaat, Garry Rumbles, and Mowafak M. Al-Jassim

Appl. Phys. Lett. 90, 193109 (2007); http://dx.doi.org/10.1063/1.2737400 (3 pages) | Cited 2 times

Online Publication Date: 7 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors investigate the localization of photons emitted at the tip during scanning tunneling microscopy measurements on atomically flat gold substrates. Emission patterns of the plasmon-mediated luminescence exhibit distinct features that are assigned to the localized modes of the surface plasmon (LSP) confined to the tunneling gap and propagating modes (PSP) coupled to the LSP by the optical cavity beneath the tip. Tunneling luminescence spectroscopy reveals that the plasmon localization at the tip increases when modes of higher energy are excited. Acquisition of local emission patterns allows us for the simultaneous imaging of LSP and PSP modes.
Show PACS
73.20.Mf Collective excitations (including excitons, polarons, plasmons and other charge-density excitations)
63.20.Pw Localized modes
73.40.Gk Tunneling

Control of core-shell structure and elemental composition of binary quantum dots

I. Levchenko, A. E. Rider, and K. Ostrikov

Appl. Phys. Lett. 90, 193110 (2007); http://dx.doi.org/10.1063/1.2737428 (3 pages) | Cited 40 times

Online Publication Date: 7 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The possibility of initial stage control of the elemental composition and core/shell structure of binary SiC quantum dots by optimizing temporal variation of Si and C incoming fluxes and surface temperatures is shown via hybrid numerical simulations. Higher temperatures and influxes encourage the formation of a stoichiometric outer shell over a small carbon-enriched core, whereas lower temperatures result in a larger carbon-enriched core, Si-enriched undershell, and then a stoichiometric SiC outer shell. This approach is generic and is applicable to a broad range of semiconductor materials and nanofabrication techniques.
Show PACS
68.65.Hb Quantum dots (patterned in quantum wells)

Giant and zero electron g factors of dilute nitride semiconductor nanowires

X. W. Zhang, W. J. Fan, S. S. Li, and J. B. Xia

Appl. Phys. Lett. 90, 193111 (2007); http://dx.doi.org/10.1063/1.2728749 (3 pages) | Cited 5 times

Online Publication Date: 8 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The electronic structures and electron g factors of InSb1−sNs and GaAs1−sNs nanowires and bulk material under the magnetic and electric fields are investigated by using the ten-band k∙p model. The nitrogen doping has direct and indirect effects on the g factors. A giant g factor with absolute value larger than 900 is found in InSb1−sNs bulk material. A transverse electric field can increase the g factors, which has obviously asymmetric effects on the g factors in different directions. An electric field tunable zero g factor is found in GaAs1−sNs nanowires.
Show PACS
73.21.Hb Quantum wires
73.22.-f Electronic structure of nanoscale materials and related systems
71.18.+y Fermi surface: calculations and measurements; effective mass, g factor
71.15.-m Methods of electronic structure calculations

Surface-induced anisotropy and multiple states in elongated magnetic nanoparticles

A. A. Leonov, I. E. Dragunov, and A. N. Bogdanov

Appl. Phys. Lett. 90, 193112 (2007); http://dx.doi.org/10.1063/1.2737830 (3 pages) | Cited 3 times

Online Publication Date: 8 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
For ellipsoidal magnetic nanoparticles the values of surface-induced uniaxial anisotropy have been derived from an analytical model as functions of aspect ratios and particle sizes. The authors show that this specific anisotropy can stabilize multiple magnetic states in the system, suppress demagnetization effects, and prevent superparamagnetism. The calculated phase diagrams indicate the stability regions of different phases and the transition fields between them. By tuning sizes, geometry, and surface anisotropy of elongated particles a well-defined sequence of magnetic switching transitions can be realized in prescribed magnetic fields. This can be used in magnetic recording and spin electronic technologies.
Show PACS
75.50.Tt Fine-particle systems; nanocrystalline materials
75.30.Gw Magnetic anisotropy
75.70.Rf Surface magnetism
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
75.40.Cx Static properties (order parameter, static susceptibility, heat capacities, critical exponents, etc.)
75.10.-b General theory and models of magnetic ordering

Investigation of twin boundary thickness and energy in CuAlNi shape memory alloy

D. Shilo, A. Mendelovich, and V. Novák

Appl. Phys. Lett. 90, 193113 (2007); http://dx.doi.org/10.1063/1.2737926 (3 pages) | Cited 9 times

Online Publication Date: 8 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The nanometer-scale thickness and energy of twin boundaries govern the martensitic twin structure and its dynamics, which are responsible for the actuation and superelasticity of shape memory alloys. In this letter the authors apply a method, which has been recently developed for investigating twin wall structures in ferroelectric crystals, on a shape memory alloy crystal. Fittings of simulated displacement fields to atomic force microscopy measurements allow them to extract the thickness of type-I twin boundaries in CuAlNi. Further, a relation between the twin boundary thickness and energy is developed and used for evaluating the twin boundary energy.
Show PACS
61.72.Mm Grain and twin boundaries
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.Dj Domain structure; hysteresis

Tunable thermal links

C. W. Chang, D. Okawa, H. Garcia, T. D. Yuzvinsky, A. Majumdar, and A. Zettl

Appl. Phys. Lett. 90, 193114 (2007); http://dx.doi.org/10.1063/1.2738187 (3 pages) | Cited 16 times

Online Publication Date: 8 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate that the thermal conductance K of individual multiwall carbon nanotubes can be controllably and reversibly adjusted by sliding the outer shells of the tube with respect to the inner core in a telescopinglike manner. K shows an exponential dependence on the telescoping distance. Tunable nanoscale thermal links have immediate implications for nano- to macroscale thermal management, biosystems, and phononic information processing.
Show PACS
66.70.-f Nonelectronic thermal conduction and heat-pulse propagation in solids; thermal waves

One-dimensional electron transport in Cu-tetracyanoquinodimethane organic nanowires

Zhixian Zhou, Kai Xiao, R. Jin, D. Mandrus, Jing Tao, D. B. Geohegan, and Stephen Pennycook

Appl. Phys. Lett. 90, 193115 (2007); http://dx.doi.org/10.1063/1.2738380 (3 pages) | Cited 9 times

Online Publication Date: 9 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The temperature and bias voltage dependent electrical transport properties of in situ fabricated Cu-tetracyanoquinodimethane organic nanowire devices are investigated. The low bias conductance and current exhibit a power-law dependence on temperature and bias voltage, respectively. The overall behavior of these nanowires can be well described by a theoretical model of nearly independent parallel chains of quantum dots created by randomly distributed defects.
Show PACS
73.63.-b Electronic transport in nanoscale materials and structures
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
61.46.-w Structure of nanoscale materials

Individual carbon nanotube soldering with gold nanoink deposition

Cedric P. R. Dockendorf, Markus Steinlin, Dimos Poulikakos, and Tae-Youl Choi

Appl. Phys. Lett. 90, 193116 (2007); http://dx.doi.org/10.1063/1.2737821 (3 pages) | Cited 14 times

Online Publication Date: 9 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A method for soldering carbon nanotubes lying on microfabricated metal pads is presented. By employing the fountain-pen principle, the authors deposited a gold nanoparticle suspension (nanoink) film on the area where the carbon nanotube contacts the metal pad. The nanoink was deposited by using a capillary tube that was pulled into a micropipette with the tip outer diameter of 2 μm. Individual carbon nanotubes were aligned selectively across the electrodes dielectrophoretically. After annealing and sintering of the nanoink pattern the four-point-probe resistance of the carbon nanotubes was measured, resulting in a good Ohmic or near-Ohmic contact (2–15 kΩ).
Show PACS
81.20.Vj Joining; welding
81.16.-c Methods of micro- and nanofabrication and processing
81.07.De Nanotubes
82.45.Yz Nanostructured materials in electrochemistry
73.40.Cg Contact resistance, contact potential
61.72.Cc Kinetics of defect formation and annealing

Arrays of crystalline C60 and pentacene nanocolumns

Jian Zhang, Ingo Salzmann, Siegfried Rogaschewski, Jürgen P. Rabe, Norbert Koch, Fujun Zhang, and Zheng Xu

Appl. Phys. Lett. 90, 193117 (2007); http://dx.doi.org/10.1063/1.2738193 (3 pages) | Cited 6 times

Online Publication Date: 9 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Crystalline nanocolumn arrays of two organic semiconductors, C60 and pentacene, were fabricated by glancing angle deposition and characterized by scanning electron microscopy and x-ray diffraction. The diameter of the nanocolumns is typically 100 nm and essentially independent of column height (up to 360 nm for pentacene). The surface diffusion length of the molecules is identified as a key parameter for the formation of the nanocolumns. Our results indicate that glancing angle deposition is a simple technique to fabricate organic crystalline nanocolumn arrays, and controlling the surface diffusion via chemical and/or morphological patterning may lead to innovative organic nanostructures.
Show PACS
81.05.Hd Other semiconductors
81.07.Bc Nanocrystalline materials
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.05.ub Fullerenes and related materials

Ultraviolet photoluminescence from ferromagnetic Fe-doped AlN nanorods

X. H. Ji, S. P. Lau, S. F. Yu, H. Y. Yang, T. S. Herng, A. Sedhain, J. Y. Lin, H. X. Jiang, K. S. Teng, and J. S. Chen

Appl. Phys. Lett. 90, 193118 (2007); http://dx.doi.org/10.1063/1.2738370 (3 pages) | Cited 15 times

Online Publication Date: 9 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Fe-doped AlN (AlN:Fe) nanorods on silicon substrates were fabricated using a catalysis-free vapor phase method. The AlN:Fe nanorods exhibited high crystalline quality and preferred c-axis orientation. The spontaneous saturated magnetization of the AlN:Fe nanorods was determined to be ∼ 0.64μB/Fe at room temperature. Room temperature photoluminescence measurement of the AlN:Fe nanorods revealed two strong ultraviolet emissions at 3.69 and 6.02 eV which could be attributed to Fe3+-related and band edge emissions, respectively. The Fe-doped AlN nanorods not only exhibited ferromagnetism but also significantly enhanced the band edge emission as compared to the undoped AlN nanorods.
Show PACS
75.50.Dd Nonmetallic ferromagnetic materials
78.67.Bf Nanocrystals, nanoparticles, and nanoclusters
78.55.Cr III-V semiconductors
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
75.50.Pp Magnetic semiconductors

Reduction of the contact resistance by doping in pentacene few monolayers thin film transistors and self-assembled nanocrystals

Claudio Vanoni, Soichiro Tsujino, and Thomas A. Jung

Appl. Phys. Lett. 90, 193119 (2007); http://dx.doi.org/10.1063/1.2738382 (3 pages) | Cited 24 times

Online Publication Date: 9 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors study the contact resistance of gold-pentacene interface by applying the transmission-line method to a few monolayers thick pentacene films in thin film transistor geometry. It was found that tetrafluorotetracyanoquinodimethane (F4TCNQ) doping reduces the contact resistance by more than a factor of 20. In addition, a significant improvement of the conductance of pentacene nanocrystals self-assembled on 10 nm gap Au nanojunction devices by F4TCNQ doping is observed. The result demonstrates the importance of doping on the performance of organic electronic devices from 10 nm scale up to 100 μm scale.
Show PACS
73.40.Cg Contact resistance, contact potential
73.40.Ns Metal-nonmetal contacts
61.72.up Other materials
85.30.Tv Field effect devices

Rolling up SiGe on insulator

F. Cavallo, R. Songmuang, C. Ulrich, and O. G. Schmidt

Appl. Phys. Lett. 90, 193120 (2007); http://dx.doi.org/10.1063/1.2737425 (3 pages) | Cited 11 times

Online Publication Date: 9 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
SiGe on insulator films of 10–50 nm thickness are fabricated by Ge condensation applying different oxidation times. The layers are released from the substrate by selectively etching the insulator film. Due to the varying Ge composition, the layers bend downward toward the substrate surface and roll up into microtubes. Depending on the Ge condensation, the strain distribution in the SiGe layers varies and allows a scaling of the tube diameters between 1 and 4 μm. Assuming pseudomorphic SiGe layers, the tube diameters are smaller than expected from continuum mechanical theory. This suggests the occurrence of additional strain in the oxidized films.
Show PACS
81.05.Hd Other semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.A- Nucleation and growth
81.65.Cf Surface cleaning, etching, patterning
81.65.Mq Oxidation
68.60.Bs Mechanical and acoustical properties

Asymmetrical AlN nanopyramids induced by polar surfaces

Jie Zheng, Xubo Song, Bo Yu, and Xingguo Li

Appl. Phys. Lett. 90, 193121 (2007); http://dx.doi.org/10.1063/1.2724915 (3 pages) | Cited 4 times

Online Publication Date: 10 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Single crystalline wurtzite aluminum nitride (AlN) tetragonal nanopyramids were fabricated through thermal evaporation of aluminum in dilute ammonia flux. The nanopyramids have their tips growing along the [01math0] direction and exhibit asymmetrical growth behavior along the ±[0001] directions. The formation mechanism was explained by a surface diffusion based model. The observation of the polar surface induced anisotropic growth in AlN nanostructures is expected to provide an insightful sample to investigate the microscopic crystal growth mechanism of AlN and other group III nitrides.
Show PACS
81.05.Ea III-V semiconductors
81.07.Bc Nanocrystalline materials
81.10.Bk Growth from vapor
81.16.Be Chemical synthesis methods

Small angle x-ray scattering measurements of lithographic patterns with sidewall roughness from vertical standing waves

Chengqing Wang, Ronald L. Jones, Eric K. Lin, Wen-Li Wu, and Jim Leu

Appl. Phys. Lett. 90, 193122 (2007); http://dx.doi.org/10.1063/1.2737399 (3 pages) | Cited 4 times

Online Publication Date: 10 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Small angle x-ray scattering (SAXS) measurements are used to quantify the wavelength and amplitude of the sidewall roughness in a lithographic line:space pattern due to vertical standing waves present during the photoresist exposure. Analytic equations are derived to model the x-ray scattering intensity and are used to determine the periodicity and amplitude of the standing wave roughness. The average periodicity, or pitch, and the linewidth were L = 422±1 nm and w0 = 148±1 nm. The period and amplitude of the standing wave roughness were λs = 65±1 nm and As = 3.0±0.5 nm. These results demonstrate the potential of SAXS measurements to quantify nondestructively and quantitatively dimensional deviations from an ideal structure.
Show PACS
85.40.Hp Lithography, masks and pattern transfer

CdSe nanowires with controllable growth orientations

C. X. Shan, Z. Liu, and S. K. Hark

Appl. Phys. Lett. 90, 193123 (2007); http://dx.doi.org/10.1063/1.2737377 (3 pages) | Cited 11 times

Online Publication Date: 11 May 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Epitaxial growths of CdSe nanowires with controllable orientations by metal organic chemical vapor deposition are obtained. Scanning electron microscopy reveals that they preferred to align along different orientations when grown on different GaAs surfaces. The geometrical relationship between their orientations and the substrates can further be changed by changing the growth temperature. They all grow along the ⟨110⟩ direction of the substrates at 480 °C, but along the ⟨111⟩ direction at 500 °C. X-ray diffraction and transmission electron microscopy confirm that they are single-crystalline wurtzite structured. Photoluminescence measurements on individual CdSe nanowires reveal their good optical properties.
Show PACS
81.05.Dz II-VI semiconductors
81.07.Vb Quantum wires
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.15.Kk Vapor phase epitaxy; growth from vapor phase
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
78.67.Lt Quantum wires
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close