共查询到20条相似文献,搜索用时 15 毫秒
1.
T. Miyanishi T. Sakai N. N. Nedyalkov M. Obara 《Applied Physics A: Materials Science & Processing》2009,96(4):843-850
Nanohole fabrication process with gold nanoparticles irradiated by femtosecond laser at different incident angles is investigated.
Nanoparticles with diameter of 200 nm and laser irradiation with center wavelength of 800 nm are used in the present study.
The analysis of the electromagnetic field distribution in the near-field zone of the particle is made by simulations based
on finite-differential time domain (FDTD) method. It is shown that when gold nanoparticle is irradiated by laser pulse surface
plasmon excitation can be induced, and associated with it, high-intensity near field is produced in a limited area around
the particle. It is found that the change of the irradiation conditions by means of irradiation from various incident directions
gives a possibility of laser nanoprocessing with tunable characteristics. Our results show that enhanced optical intensity
is able to be induced on the substrate surface regardless of incident direction of the laser due to the image charge interaction with the substrate. Furthermore, the use of p-polarized
laser irradiation at a certain angle gives a minimum of the spatial dimensions of the enhanced zone on the substrate which
is about two times smaller than that obtained at normal incidence. 相似文献
2.
V. Kosalathip A. Dauscher B. Lenoir S. Migot T. Kumpeerapun 《Applied Physics A: Materials Science & Processing》2008,93(1):235-240
The technique of laser fracture in a liquid medium has been applied to the synthesis of n-type (Bi0.95Sb0.05)2 (Te0.95Se0.05)3 and p-type (Bi0.2Sb0.8)2Te3 semiconducting nanopowders which are the best conventional materials currently used for thermoelectric applications at ambient
temperature. The nanopowders have been prepared with a high yield in an especially built-up cell. Laser fracture in water
of micronsized powders has been applied, using a nanosecond Nd:YAG laser working at 532 nm. The obtained powders have been
characterized by scanning and transmission electron microscopy and by X-ray diffraction. The mean diameter is about 10 nm
and the phase of the initial powders is kept. To test the potentiality of these nanosized materials, we have shown the feasibility
to produce a pn hetero-junction. 相似文献
3.
Tae Woo Lim Yong Son Dong-Yol Yang Hong-Jin Kong Kwang-Sup Lee Sang Hu Park 《Applied Physics A: Materials Science & Processing》2008,92(3):541-545
Effective scanning is an important issue in two-photon induced stereolithography (TPS) for the reduction of the processing
time required to fabricate three-dimensional (3D) nano/microstructures. In large-scale TPS based on a stage-scanning system,
the large processing time due to the intrinsic slow response in the stage scanning system is a major obstacle to its use as
a practical nanofabrication process. To overcome this drawback, we propose a continuous scanning method (CSM) for a stage-scanning
system. In CSM, a pattern is generated with continuous movement of the stage during laser beam exposure. A stable fabrication
window (SFW), which enables uniform motion of the stage without errors considering the stage characteristics, was obtained
from fundamental experiments. Within the condition of a SFW, 2D and 3D microstructures having nanoscale details were fabricated
with a whole scale range of several hundred micrometers using CSM. 相似文献
4.
Wei Wu Ekaterina Ponizovskaya Evgenia Kim David Cho Alexander Bratkovsky Zhaoning Yu Qiangfei Xia Xuema Li Y. Ron Shen S. Y. Wang R. Stanley Williams 《Applied Physics A: Materials Science & Processing》2009,95(4):1119-1122
We have studied the geometry dependency of fishnet-like negative refractive index meta-materials (NIMs), and developed a process
to fabricate such NIMs using nanoimprint lithography (NIL) in a controlled way for it to achieve negative refractive index
in the desired frequency range. As an example, we fabricated a fishnet structure with a minimum negative refractive index
of −1.7 at 1560 nm, which was only 10 nm off the targeted wavelength of 1550 nm. 相似文献
5.
Laila Jaber-Ansari Myung Gwan Hahm Tae Hoon Kim Sivasubramanian Somu Ahmed Busnaina Yung Joon Jung 《Applied Physics A: Materials Science & Processing》2009,96(2):373-377
Large-scale room-temperature liquid-phase directed assembly of highly organized single-walled carbon nanotubes (SWNT) over
large areas is demonstrated. The presented process utilizes lithographically patterned template to guide the fluidic self-assembly
of SWNTs on a silicon-dioxide substrate. The width of these highly organized SWNT structures are in the micron range while
their heights are in orders of nanometers. Room temperature electrical I–V characterization of these fabricated high coverage SWNT wires show linear ohmic behavior. The resistivity of these assembled
SWNT network is in the order of 10−6 Ω m demonstrating their metallic characteristics during conductance. Scaling of the assembly processes on a wafer level with
high yield is demonstrated. Our developed assembly process is compatible with complimentary metal oxide semiconductor (CMOS)
processes and provides a simple and flexible way of building SWNT nanotube-based electronics in a large scale. 相似文献
6.
T. V. Kononenko P. Alloncle V. I. Konov M. Sentis 《Applied Physics A: Materials Science & Processing》2009,94(3):531-536
Blister-based laser induced forward transfer (BB-LIFT) is a promising technique to produce surface microstructures of various
advanced materials including inorganic and organic micro/nanopowders, suspensions and biological micro-objects embedded in
life sustaining medium. The transferred material is spread over a thin metal film irradiated from the far side by single laser
pulses through a transparent support. Interaction of the laser pulse with the metal–support interface under optimized conditions
causes formation of a quickly expanding blister. Fast movement of the free metal surface provides efficient material transfer,
which has been investigated for the case of diamond nanopowder and diamond-containing suspension. The unique features of the
given technique are universality, simplicity and efficient isolation of the transferred material from the ablation products
and laser heating. 相似文献
7.
M. Salaün M. Audier M. Duneau F. Delyon 《Applied Physics A: Materials Science & Processing》2008,93(1):105-110
In 2000, Campbell et al. (Nature 404:53, 2000) have shown that three-dimensional periodic nanostructures can be obtained from UV laser interference irradiation of photoresist
for 6 nanosecond single pulse. We have developed a similar experiment for photolytic gas phase decomposition and for photopatternable
organic–inorganic hybrid resins.
Different steps in results, presently reported, were first to determine the characteristics of both the 3D interference pattern
and interferometer to be associated to a CVD reactor and second to verify the mechanical stability of the set up confirmed
with the structuration of a siloxane based methacrylic resins by UV polymerization and finally to grow periodic nanostructures
by photolytic gas phase decomposition of chromyl chloride. The experimental results obtained so far indicate that, depending
on the electromagnetic energy density, a vapor phase decomposition of chromyl chloride leads to periodic arrays of either
Cr–O amorphous or Cr2O3 particles on glass and (001)TiO2 substrates at room temperature. 相似文献
8.
ZnO–CuO core–shell nanorods and CuO-nanoparticle–ZnO-nanorod integrated structures were synthesized for the first time by
a two-stage solution process. Scanning electron microscopy and high-resolution transmission electron microscopy show that
the diameter and the length of the nanorods are around 60 and 800 nm, respectively. The morphologies of outer CuO could be
varied from nanoparticles to nanoshells by adjusting the solvent and dipping processes of copper (II) nitrate solution. The
CuO nanoparticles are single-crystalline or highly textured structures with size of around 30 nm. The CuO shell with thickness
of around 10 nm is constructed of nanocrystals with sizes in the range of 3–10 nm embedded in an amorphous matrix. Room-temperature
cathodoluminescence measurements of the CuO–ZnO nanocomposites exhibit relatively sharp ultraviolet emissions at 380 nm as
well as broad green and yellow emissions at 500 and 585 nm. The p-CuO/n-ZnO one-dimensional nanocomposites are promising for
optoelectronic nanodevice applications. 相似文献
9.
S. Mátéfi-Tempfli M. Mátéfi-Tempfli L. Piraux 《Applied Physics A: Materials Science & Processing》2009,96(3):603-608
We report on different approaches that we have adopted and developed for the fabrication of nanowires and nanostructures.
Methods based on template synthesis and on self organization seem to be the most promising for the fabrication of nanomaterials
and nanostructures due to their easiness and low cost.
The development of a supported nanoporous alumina template and the possibility of using this template to combine electrochemical
synthesis with lithographic methods open new ways for the fabrication of complex nanostructures. The numerous advantages of
the supported template and its compatibility with microelectronic processes make it an ideal candidate for further integration
into large-scale fabrication of various nanowire-based devices. 相似文献
10.
ZnO nanoparticles, nanowires, and nanowalls were synthesized rapidly on Si via thermal decomposition of zinc acetate by a
modified chemical vapor deposition at a low substrate temperature of 200–250°C for the first time. The diameters of the synthesized
nanoparticles and nanowires are around 100 and 30 nm, respectively, and the thickness of nanowalls is around 20 nm. High-resolution
transmission electron microscopy shows that the nanowires as well as nanowalls are single-crystalline, and the nanoparticles
are highly-textured poly-crystalline structures. Room-temperature photoluminescence spectra of the nanostructures show strong
ultraviolet emissions centered at 368–383 nm and weak violet emissions at around 425 nm, indicating good crystal quality.
The study provides a simple and efficient route to synthesize ZnO diverse nanostructures at low temperature. 相似文献
11.
Shingo Kanehira Kiyotaka Miura Kazuyuki Hirao Naoya Shibata Yuichi Ikuhara 《Applied Physics A: Materials Science & Processing》2008,92(4):913-916
We show a unique technique to form dense dislocations locally inside a MgO single crystal with a rock-salt type structure
using femtosecond (fs) laser irradiation. Cross-shaped patterns of micrometer size, originating from densely introduced dislocations,
are formed spontaneously around the focal point. We controlled the three-dimensional propagation of the dislocations by adjusting
the pulse energy of the fs laser and NA of objective lens. The technique may open up a new field of dislocation technology
for optical applications. 相似文献
12.
Nanoscale laser processing and diagnostics 总被引:2,自引:0,他引:2
David Hwang Sang-Gil Ryu Nipun Misra Hojeong Jeon Costas P. Grigoropoulos 《Applied Physics A: Materials Science & Processing》2009,96(2):289-306
The article summarizes research activities of the Laser Thermal Laboratory on pulsed nanosecond and femtosecond laser-based
processing of materials and diagnostics at the nanoscale using optical-near-field processing. Both apertureless and apertured
near-field probes can deliver highly confined irradiation at sufficiently high intensities to impart morphological and structural
changes in materials at the nanometric level. Processing examples include nanoscale selective subtractive (ablation), additive
(chemical vapor deposition), crystallization, and electric, magnetic activation. In the context of nanoscale diagnostics,
optical-near-field-ablation-induced plasma emission was utilized for chemical species analysis by laser-induced breakdown
spectroscopy. Furthermore, optical-near-field irradiation greatly improved sensitivity and reliability of electrical conductance
atomic force microscopy enabling characterization of electron tunneling through the oxide shell on silicon nanowires. Efficient
in-situ monitoring greatly benefits optical-near-field processing. Due to close proximity of the probe tip with respect to
the sample under processing, frequent degradation of the probe end occurs leading to unstable processing conditions. Optical-fiber-based
probes have been coupled to a dual-beam (scanning electron microscopy and focused ion beam) system in order to achieve in-situ
monitoring and probe repair. 相似文献
13.
Qiang Zhang Jia-Qi Huang Meng-Qiang Zhao Wei-Zhong Qian Fei Wei 《Applied Physics A: Materials Science & Processing》2009,94(4):853-860
Based on the analysis of catalyst particle formation and carbon nanotube (CNT) array growth process in floating catalyst chemical
vapor deposition (CVD), delicately controlled gaseous carbon sources and catalyst precursors were introduced into the reactor
for the controllable growth of CNT array. The low feeding rate of ferrocene was realized through low-temperature sublimation.
With less ferrocene introduced into the reactor, the collision among the in situ formed iron atoms decreased, which led to the formation of smaller catalyst particles. The mean diameter of the CNT array,
grown at 800oC, decreased from 41 to 31 nm when the ferrocene-sublimed temperature reduced from 80 to 60oC. Furthermore, low growth temperature was adopted in synthesis, through the modulation of the CNT diameter, by controlling
the sintering of catalyst particles and the collision frequency. When the growth temperature was 600oC, the as-grown CNTs in the array were with a mean diameter of 10.2 nm. If propylene was used as carbon source, the diameter
can be modulated in similar trends. The diameter of CNT can be modulated by the parameter of the operation using the same
substrate and catalyst precursor without other equipment or previous treatment. Those results provide the possibility for
delicately controllable synthesis of CNT array via simple floating catalyst CVD. 相似文献
14.
J. Kettle R. T. Hoyle S. Dimov 《Applied Physics A: Materials Science & Processing》2009,96(4):819-825
The fabrication of Step-and-Flash Imprint Lithography (S-FIL) templates with line widths of 50 nm is described in this work.
The structures have been patterned using a Ga+ focused ion beam (FIB) in a quartz template. FIB milling is generally accompanied with re-deposition effects, which represent
a hindrance to densely patterned nanostructures required in most NIL applications. To reduce these re-deposition effects,
in this research, xenon difluoride (XeF2) enhanced FIB etching was applied that also increases the material removal rates in comparison to pure kinetic ion sputtering.
To optimise the process when using XeF2 gas the following ion scanning parameters have been examined: ion dose, beam current, dwell time and beam overlap (step size).
It has been found that the assisting gases at very low doses do not bring significant etching enhancements whilst the sputtering
rates have increased at high doses. Using the XeF2 gas-assisted etching, FIB structuring has been used to fabricate <100 nm structures onto quartz S-FIL templates. The presence
of XeF2 considerably enhances the etching rate of quartz without any significant negative effects on the spatial resolution of the
FIB lithographic process and reduces the template processing time. 相似文献
15.
L. Englert M. Wollenhaupt L. Haag C. Sarpe-Tudoran B. Rethfeld T. Baumert 《Applied Physics A: Materials Science & Processing》2008,92(4):749-753
Laser material processing of dielectrics with temporally asymmetric femtosecond laser pulses of identical fluence, spectrum,
and statistical pulse duration is investigated experimentally. To that end single shot structures at the surface of fused
silica as a function of fluence and pulse shape are analyzed with the help of scanning electron microscopy. Structures for
the bandwidth limited pulses show the known expansion in structure size with increasing laser fluence approaching the diffraction
limit, which is 1.4 μm for the 0.5NA microscope objective used. In contrast, structures from the asymmetric pulses are remarkably
stable with respect to variations in laser fluence and stay below 300 nm despite doubling the fluence. Different thresholds
for surface material modification with respect to an asymmetric pulse and its time reversed counterpart are attributed to
control of different ionization processes. 相似文献
16.
N. V. Tarasenko A. V. Butsen A. A. Nevar 《Applied Physics A: Materials Science & Processing》2008,93(4):837-841
Tight focusing of a sub-picosecond laser pulse in a transparent dielectric provides a mean for localized deposition and plasma
formation. A micro-explosion in a confined geometry results in a sub-micron cavity formation. Our numerical simulations show
the cavity size is strongly dependent on the parameters of the equation of state such as the Grüneisen coefficient or the
latent heat of sublimation. A comparison of numerical simulations with experimental data should allow a tuning of equations
of state in the domain of extreme parameters 相似文献
17.
J. J. Camacho M. Santos L. Díaz J. M. L. Poyato 《Applied Physics A: Materials Science & Processing》2009,94(2):373-380
We have used ferrocene and paraffin wax as novel precursor and solvent for the growth of iron oxide nanoparticles. The proposed
method of growth has several advantages over existing methods of growth using iron pentacarbonyl a precursor. Highly crystalline
and monodispersed particles are obtained which assemble in two- and three-dimensional hexagonal closed packed superlattices.
Growth kinetics has been studied by varying concentration of the precursor and time of growth. A phenomenological model has
been proposed to explain the growth kinetics. 相似文献
18.
A. Kisner M. R. Aguiar A. F. Vaz A. Rojas F. A. Cavarsan J. A. Diniz L. T. Kubota 《Applied Physics A: Materials Science & Processing》2009,94(4):831-836
The ultimate limits of size of the current metal-oxide-semiconductor capacitors can be overcome by preparation of three-dimensional
devices that can vertically be biased using one-dimensional metal nanostructures. Here, we present a general and efficient
approach to the assembly and integration of Au nanocrystals into functional nanoelectrodes of three-dimensional submicrometer-MOS
(0.35 μm2) capacitors, presenting an ultra high capacitance (24±1 pF). The Au nanocrystals were directly produced into a nanoporous
template of anodized aluminum oxide that was evaluated, and the electrical characterization of this device corroborates the
formation of the MOS capacitor. Flat band voltage is independent of sweep voltage range, and negligible hysteresis of capacitance-voltage
curves is observed when sweep voltage ranges from positive to negative and turned again to positive bias. In addition, experimental
results match theoretical analysis and indicate the presence of free surface charges stored in the Au nanostructures. The
demonstrated ability to control the assembling of the nanocrystals and the results of electrical characterization indicate
that the embedded Au nanoelectrodes have a high potential for memory applications based on three-dimensional devices. 相似文献
19.
L. Egerhazi Zs. Geretovszky T. Szorenyi 《Applied Physics A: Materials Science & Processing》2008,93(3):789-793
Since the advent of pulsed laser deposition (PLD), several different target-substrate arrangements have been proposed. Besides
the most common on-axis PLD, several off-axis geometries were studied, mainly to protect the substrate from the agglomerated
species (clusters, droplets, particulates) of the plasma plume, which are detrimental to the homogeneity of films. Recently
we introduced a novel geometry, termed inverse pulsed laser deposition (IPLD), in which the substrate is placed parallel to
and slightly above the target plane. In this paper we summarize our results on this new geometry, and show how it can extend
the perspectives of pulsed laser deposition, e.g., by improving the surface morphology of the films. Effects of ambient pressure
are presented and exemplified on metallic and compound IPLD films, including Ti, CN
x
, and Ti-oxides. AFM topographic images are used to prove that under optimized conditions IPLD is capable of growing compact
and smooth films that are superior to PLD ones. A special—but easy-to-implement—IPLD arrangement is also introduced that considerably
improves the homogeneity of IPLD films. In this geometry, the properties (e.g., deposition rate and roughness) of the films
grown in the 1–25 Pa pressure domain are examined. 相似文献
20.
C. T. Yip C. S. K. Mak A. B. Djurišić Y. F. Hsu W. K. Chan 《Applied Physics A: Materials Science & Processing》2008,92(3):589-593
Titania porous layer has been fabricated on titania nanotubes for dye sensitized solar cells and the photovoltaic performance
of solar cells with mixed morphology has been investigated. The porous layer results in a similar improvement in the short
circuit current density to conventional TiCl4 treatment, although the mechanisms responsible for the observed increase in the efficiency are different. This enables further
improvements of the photovoltaic performance by combining the TiCl4 treatment and porous layer deposition, so that the efficiency in the case of ∼5 μm long tubes increases on average from ∼1.6
to ∼2.2%. 相似文献