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- Front Matter: Volume 8104
- Opening Session
- Plasmonics
- Optics
- Homogenization Studies
- Applications
- Nanostructured Porous Silicon
- Fabrication and Characterization I
- Fabrication and Characterization II
- Fabrication and Characterization III
- Poster Session
Front Matter: Volume 8104
Front Matter: Volume 8104
Show abstract
This PDF file contains the front matter associated with SPIE Proceedings Volume 8104, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing.
Opening Session
Green nanotechnology
Show abstract
Nanotechnology, in particular nanophotonics, is proving essential to achieving green outcomes of
sustainability and renewable energy at the scales needed. Coatings, composites and polymeric structures used
in windows, roof and wall coatings, energy storage, insulation and other components in energy efficient
buildings will increasingly involve nanostructure, as will solar cells. Nanostructures have the potential to
revolutionize thermoelectric power and may one day provide efficient refrigerant free cooling.
Nanomaterials enable optimization of optical, opto-electrical and thermal responses to this urgent task.
Optical harmonization of material responses to environmental energy flows involves (i) large changes in
spectral response over limited wavelength bands (ii) tailoring to environmental dynamics. The latter includes
engineering angle of incidence dependencies and switchable (or chromogenic) responses. Nanomaterials can
be made at sufficient scale and low enough cost to be both economic and to have a high impact on a short
time scale. Issues to be addressed include human safety and property changes induced during manufacture,
handling and outdoor use. Unexpected bonuses have arisen in this work, for example the savings and
environmental benefits of cool roofs extend beyond the more obvious benefit of reduced heat flows from the
roof into the building.
Plasmonics
Surface multiplasmonics
Show abstract
The planar interface of a metal and a dielectric material can guide multiple surface-plasmon-polariton (SPP)
waves-all of the same frequency, but different phase speed, attenuation rate, and spatial profiles of fields-
provided that the dielectric material is periodically nonhomogeneous in the direction normal to the interface.
Theoretical and experimental research during the last four years have validated this idea, thereby engendering
the research area of surface multiplasmonics.7
High-throughput nanofabrication of plasmonic structures and metamaterials with high resolution nanostencil lithography
Show abstract
We demonstrate a novel fabrication approach for high-throughput fabrication of engineered plasmonic antenna arrays
and metamaterials with Nanostencil Lithography (NSL). NSL technique, relying on deposition of materials through a
shadow mask, offers the flexibility and the resolution to fabricate radiatively engineer nanoantenna arrays for excitation
of collective plasmonic resonances. We confirmed that the antenna arrays fabricated by NSL shows high optical quality
similar to EBL fabricated ones. Furthermore, we show nanostencils can be reused multiple times to fabricate selfsame
structures with identical optical responses repeatedly and reliably. This capability is particularly useful when highthroughput
replication of the optimized nanoparticle arrays is desired. In addition to its high-throughput capability, NSL
permits single step nanofabrication of plasmonic devices on surfaces that are difficult to work with electron/ion beam
techniques. Nanostencil lithography is a resist free process thus allows the transfer of the nanopatterns to any planar
substrate whether it is conductive, insulating or magnetic. As proof of the versatility of the NSL technique, we show
fabrication of plasmonic structures and metamaterials in variety of geometries. In metamaterial and plasmonic devices,
unique geometries with small gaps and asymmetries can induce novel electromagnetic responses such as plasmon
induced transparency and also giant near-field intensities that are important for enhanced vibrational spectroscopy and
non-linear optics applications. This nanofabrication scheme, enabling the reusability of stencil and offering flexibility on
the substrate choice and nano-pattern design could significantly enhance wide-use of plasmonics in sensing technologies.1
Spatiotemporal-photothermal and photoacoustic conversions with local plasmon resonators
Show abstract
We have investigated the heat generation from gold nanoparticles resulting from their local plasma resonance. The selfassembly
of Au nanoparticle arrays/dielectric layer/Ag mirror sandwiches, namely, local plasmon resonators, have been
demonstrated by using a dynamic oblique deposition technique. Due to strong interference, the optical absorption of the
local plasmon resonator chips we prepared is successfully controlled between 0.0% and 97% in the near-infrared region,
by changing the thickness of the dielectric layer. We evaluated the heat generation from Au nanoparticles by measuring the
temperature of water with which a cell prepared on a chip was filled under laser illumination. The temperature increase of
the water is proportional to the optical absorption of the local plasmon resonator chips. This suggests that the photothermal
conversion efficiency can be controlled by interference. In order to show the temporal controllability of heat generation,
we also demonstrated photoacoustic measurements. The acoustic signal from the local plasmon resonator chips was much
larger than the signal not only form high reflective Ag thin film but also from the graphite. These features indicate that the
local plasmon resonators are suitable for nanoheaters which are capable of spatio-temporal control.
Monitoring the reactivity of Ag nanoparticles for different atmospheres by using in situ and real-time optical spectroscopy
Show abstract
Surface differential reflectance spectroscopy (SDRS), an optical characterization technique, is sensitive enough to
observe the minute changes in the surface plasmon resonance (SPR) of noble metal nanoparticles (NPs). This SPR,
which causes a sharp absorption of light in the visible range, is extremely sensitive not only to the morphology and
organization of the NPs, but also to the chemical atmosphere surrounding them. Hence, taking SPR as a signature
phenomenon, we have studied the reactivity of Ag NPs using a dedicated in situ SDRS set-up mounted on a magnetron
sputtering machine. Real-time optical characterizations were possible not only during the deposition of Ag NPs, but also
during their exposure to gases such as O2, N2, Ar, either non-ionized or partially ionized. This optical study reveals that
Ag NPs are reactive to non-ionized O2 exposure, which induces modifications in the SPR characteristics (width,
amplitude and position of the absorption band) in contrast to N2 and Ar. Moreover, this study also evidences a complete
disappearance of the SPR when Ag NPs are exposed to partially ionized oxygen species O2(+) as well as a significant
reactivity of the NPs exposed to N2(+), while Ar remains non-reactive in both non-ionized and partially ionized forms.
Optics
Nanostructure effects and the performance of optical interference coatings
Show abstract
The theory of "classical" optical interference coatings is based on assumptions like ideal homogeneity and
isotropy of the materials, as well as absolutely smooth and infinitesimally thin interfaces between the
individual coating materials. Within the framework of these assumptions, there exists an elaborated theoretical
apparatus for solving design and characterization tasks for optical coatings. At the same time, coating
deposition techniques have been perfected in order to match with the requirements of homogeneity and
smoothness of these coatings in practice.
Remaining discrepancies between the theoretically predicted and practically achieved coating performance can
- at least partially - be attributed to the violation of the above-mentioned ideal assumptions. But a closer look
on this matter reveals a more differentiated picture: Nanostructure effects can be tackled as additional degrees
of freedom for coating design, and can lead to useful property combinations that are inaccessible to "classical"
coatings prepared on the basis of the traditionally available coating materials.
This presentation deals with practical examples, where explicit violations of the usually assumed perfect
homogeneity and smoothness of the coatings have resulted in novel and innovative coating material properties
or coating designs. Examples include:
- Effects of noble metal islands embedded in semiconductor films: applications in photovoltaics
- Antireflection effects of nanostructured surfaces: motheye-structures
- Effects of nanoporosity in oxide films on refractive index, thermal shift and mechanical stress:
balanced coating properties
The examples demonstrate the possible benefits of the exploitation of nanostructure-caused effects in
interference coating science and technology.
Using a single anisotropic thin film as a phase retarder for oblique incident wave
Show abstract
This work presents a wide angle phase retarder by using a single anisotropic Ta2O5 columnar thin film. The single
anisotropic Ta2O5 columnar thin film can provide phase retardation between two tangential eigenvectors to modulate
the polarization state of light reflected from the prism-coupling system (BK7 prism/anisotropic thin film/air). In
experiment, glancing angle deposition technique is used to prepare single layer film of Ta2O5 tilted nanorod array with
thickness 270nm. In this analysis, we use wave tracing based on the Berreman calculus to calculate the variations of
phases of eigen-waves in the anisotropic thin film as the electromagnetic wave is incident to the prism-coupling system.
The uniform phase retardation can be observed in a wide angle range. A linearly polarized incident ray can be reflected
as a specific elliptical polarized ray uniformly over the range. Similarly, the wide angle and broadband polarization
conversion reflectance with high efficiency also exists in the single anisotropic Ta2O5 columnar thin film. The single
anisotropic Ta2O5 columnar thin film can be useful for the further application in optical components design.
Quenched transmission of light through ultrathin metal films
Show abstract
We discuss optical properties of ultrathin metal films, with particular attention to the phenomenon of quenched
transmission. Transmission of light through an optically ultrathin metal film with a thickness comparable to its
skin depth is significant. We demonstrate the quenched transmission through the ultrathin metal films when they
are periodically modulated. We also discuss the physics behind it and explain how this abnormal phenomenon
is ascribed to surface plasmon resonance effects.
Optical properties of UT-shaped plasmonic nanoaperture antennas
Show abstract
In this paper, we present numerical and experimental results on optical properties of a multi-resonant UT-shaped
plasmonic nanoaperture antenna for enhanced optical transmission and near-field resolution. We propose different
structure designs in order to prove the effect of geometry on resonance spectrum and near-field enhancement.
Theoretical calculations of transmission spectra and field distributions of UT-shaped nano-apertures are performed by
using three-dimensional finite-difference time-domain method. The results of these numerical calculations show that
transmission through the apertures is indeed concentrated in the gap region. In addition to theoretical calculations, we
also performed a lift-off free plasmonic device fabrication technique based on positive resist electron beam lithography
(EBL) and reactive ion etching in order to fabricate UT-shaped nanostructures. For further confirmation of the multiresonant
behavior, we checked the individual U-and T-shaped nano-aperture antenna responses. We also studied the
parameter dependence of the structure to determine the control mechanism of the spectral response. Theoretical
calculations are supported with experimental results to prove the enhanced field distribution and multi-resonant behavior
which can be suitable for infrared detection of biomolecules, wavelength-tunable filters, optical modulators, and ultrafast
switching devices.teInp
Optical birefringence in a bideposited symmetric nanorod arrays
Show abstract
In this work, the birefringence of bideposited symmetric nanorod array is investigated. The Ta2O5 nanorod arrays
composed of several subdeposits are fabricated by serial bideposition (SBD) technique. Each nanorod consists of several
identical units and each unit consists of symmetrical sections ABA. From the lateral view of the structure, the nanorod
array is a symmetrical multilayered. The deposition planes for layer A and layer B are perpendicular to each other. For
normal incident ray, the polarization-dependent refractive indices and phase thicknesses of the film are presented as
functions of wavelength and optical constants of each layer. The transmittance spectra of symmetrical sections have a
pass band property as the equivalent refractive indices are real. The principal indices of the Ta2O5 nanorod arrays with
each subideposition thickness of 3 nm associated with the two orthogonal polarizations are measured by ellipsometer
when the deposition angle is changed from 70° to 80°. According to principal indices database, a uniform phase
retardation between the two orthogonal polarization directions can be designed for a specific wavelength range.
Homogenization Studies
Effective properties of metamaterials
Show abstract
Properties of metamaterials are usually discussed in terms of biaxial anisotropic material parameters. To consider the
underlying constitutive relations as valid, it is required that only weak spatial dispersion occurs. At operational
frequencies of optical metamaterials this assumption often ceases to be valid. A description using effective material
properties tends to be inadequate and new approaches are required. We outline here our latest achievements along this
direction and discuss two approaches. The first one assumes that if it is not possible to introduce useful effective
properties, a more primary source of information should be used to quantify metamaterials, leading to a characterization
of metamaterials in terms of Jones matrices. We discuss the implications of this description and show that all
metamaterials can be categorized into five classes, each with distinct properties. The second approach resorts to an
effective description but restricts its considerations to a dispersion relation, characterizing the propagation of light in
bulk metamaterials, and an impedance, characterizing the coupling between metamaterials and their surroundings.
Definitions of both properties linked to a single Bloch mode are discussed and metamaterials are introduced which can
be homogenized while considering only this single mode.
On dipole emission from an infiltrated chiral sculptured thin film
Show abstract
The investigation of the far-field radiation from a dipole source inside an infiltrated chiral sculptured thin films
(CSTF) was extended to consider different positions of the dipole source and the presence or absence of fluid
above the CSTF. From numerical studies, we found that within one structural period, the far-field radiation
pattern varies as the source position varies and the pattern approximately repeats when the source is moved by
one structural period. The intensity of the emitted radiation is less influenced by the presence of fluid above
the CSTF. When the source is placed at the centre of the CSTF, the right circular polarization radiation is
preferentially emitted through upper face of the CSTF whereas left circular polarization radiation is preferentially
emitted through lower face.
Homogenization of metallic metamaterials and electrostatic resonances
Show abstract
The homogenization of arrays of metallic rods was studied. Using standard homogenization theory, the effective
permittivity was obtained. The onset of resonances was evidenced and showned to be linked with the negative
sign of the real part of the permittivity. Numerical computations were performed to test the homogeneous
model.
Applications
Microspot surface enhanced fluorescence from sculptured thin films for control of antibody immobilization
Show abstract
Nano-sculptured thin films (STF) are prepared by the glancing angle deposition technique and take different forms of
nano columnar structures. Varieties of STFs are investigated to find the optimum structure for biosensing based on the
surface enhanced fluourescence (SEF). The highest amplification of fluorescent signal is found for Ag based STFs on
fused silica giving an enhancement factor of x23°, where h=400nm, d=75nm, á=23o relative to Ag dense film using
fluorescent dye Rhodamine 123. Based on this, a demonstration of monitoring of antibodies and even confirmation of
successful immobilization of the receptors presented. Bound antibody to the thiol self assembly monolayer on sample
surface is then quantified by means of the fluorescent signal. Upon excitation of the fluorophore by Hg source light, a
CCD camera with a controlled exposure time detects the pattern of fluorescent antibody/E-coli bacteria colonies on the
STF surface. A fiber optic holder attached to the microscope allowed quantitative measurement of the fluorescence
spectrum on a microspot.
Nanostructured Porous Silicon
Intimate effects of surface functionalization of porous silicon microcavities on biosensing performance
M. Martin,
L. Massif,
E. Estephan,
et al.
Show abstract
We study the effect of different surface functionalization methods on the sensing performances of porous silicon (PSi)
microcavities when used for detection of biomolecules. Previous research on porous silicon demonstrated versatility of
these devices for sensor applications based on their photonic responses. The interface between biological molecules and
the Si semiconductor surface is a key issue for improving biomolecular recognition in these devices.
PSi microcavities were fabricated to reveal reflectivity pass-band spectra in the visible and near-infrared domain. To
assure uniform infiltration of proteins the number of layers of Bragg mirrors was limited to five, the first layer being of
high porosity. In one approach the devices were thermally oxidized and functionalized to assure covalent binding of
molecules. Secondly, the as etched PSi surface was modified with adhesion peptides isolated via phage display
technology and presenting high binding capacity for Si. Functionalization and molecular binding events were monitored
via reflectometric interference spectra as shifts in the resonance peaks of the cavity structure due to changes in the
refractive index when a biomolecule is attached to the large internal surface of PSi. Improved sensitivity is obtained due
to the peptide interface linkers between the PSi and biological molecules compared to the silanized devices. We
investigate the formation of peptide-Si interface layer via X-ray photoelectron spectroscopy, scanning tunneling
microscopy and scanning electron microscopy.
Infiltration of Fe3O4-nanoparticles into porous silicon with respect to magnetic interactions
P. Granitzer,
K. Rumpf,
M. Reissner,
et al.
Show abstract
Mesoporous silicon (PS) is used as matrix for infiltration of Fe3O4 nanoparticles (5 and 8 nm). The structure and
magnetic behaviour of such composites are investigated and a correlation between the morphology of the nanocomposite
(structure of the matrices, size and distribution of Fe3O4 particles) and the magnetic properties of the system is figured
out. This system shows a superparamagnetic (SPM) behaviour at room temperature and becomes ferromagnetic (FM) at
lower temperatures. The transition temperature between SPM and a blocked state depends on the particle size, their
coating and on their magnetic interactions. Dipolar coupling between the particles can be influenced by varying the PS
morphology as well as by the filling factor. The blocking temperature (TB) of the composite is tuneable and changes due
to the variation of dipolar coupling of the Fe3O4-particles (distance between particles). Results gained from electron
microscopy and tomography, respectively such as size and spatial distribution of the particles together with the magnetic
data lead to a more detailed knowledge of the Fe3O4/silicon nanocomposite system.
Controlled skeletal progenitor cell migration on nanostructured porous silicon/silicon micropatterns
V. Torres-Costa,
V. Sánchez-Vaquero,
Á. Muñoz-Noval,
et al.
Show abstract
In this work nanostructured porous silicon (nanoPS) was used for the fabrication of surface micropatterns aiming at
controlling cell adhesion and migration. In particular, surface patterns of nanoPS and Si were engineered by high-energy
ion-beam irradiation and subsequent anodization. It was found that human skeletal progenitor cells are sensitive to oneand
two-dimensional patterns and that focal adhesion is inhibited on nanoPS areas. In spite of this anti-fouling
characteristics, studies on patterns with reduced Si areas show that cells conform to nanoPS pathways favoring migration
through cell protrusion, body translocation and tail retraction from two parallel Si traction rails. Moreover, migration can
be blocked and cells tend to arrange when grid patterns with the appropriate dimensions are fabricated. The experimental
results confirm that progenitor cells are able to exploit nanoPS anti-fouling designs by adapting to it for migration
purposes.
Investigation of the interfaces of a metal/porous silicon nanocomposite and its influence on the physical properties
K. Rumpf,
P. Granitzer,
M. Reissner,
et al.
Show abstract
Metal-nanostructures are electrochemically deposited within the pores of porous silicon to achieve a hybrid material with
specific magnetic properties. The metal structures can be precipitated with various geometries and different spatial
distributions depending on an accurate control of the deposition conditions. This method allows to deposit structures as
spheres, ellipsoids or wires with a size up to a few micrometers whereas the diameter corresponds to the pore-diameter.
Furthermore small Ni-particles between 3 and 6 nm can be deposited in a densely packed arrangement on the pore walls
forming a quasi metal tube. Analysis of this tube-like arrangement by transmission electron microscopy shows that the
distribution of the Ni-particles is quite narrow, which means that the distance between the particles is smaller than 10
nm. Such a close arrangement of the Ni-particles assures magnetic interactions between them. Due to their size these
small Ni-particles are superparamagnetic but dipolar coupling between them results in a ferromagnetic behaviour of the
whole system. Moreover, to investigate the interface between the materials in more detail electron energy loss
spectroscopy is employed. Magnetic measurements show an anisotropy between easy axis and hard axis magnetization
which corresponds to the behaviour of a metal tube. This composite is an interesting candidate for integrable magnetic
and magneto-optic devices and also for spin-injection from a ferromagnetic metal into silicon.
Fabrication and Characterization I
An investigation on magnetic responses in Ag-SiO[sub]2[/sub]-Ag nanosandwich structures
Show abstract
In this work, we investigate magnetic responses in various Ag-SiO2-Ag nanosandwich structures at
visible wavelengths. The two electric resonant modes corresponding to the in-phase (symmetric) and
anti-phase (asymmetric) electric dipole on the top and the bottom nanopillars are observed by the finite
difference time domain (FDTD) simulation. In the asymmetric resonant mode, the phases of electric
fields oscillating in the top and bottom pillars have opposite directions, leading to a virtual current loop
that induces the magnetic field reversal. The nanosandwich structure produces a large enhancement of
the magnetic field as the thickness of SiO2 nanopillar is much smaller than wavelength. By increasing
the diameter of nanopillars from 150 nm to 250 nm, the inverse magnetic response wavelength shifts
from 532 nm to 690 nm. On account of the magnetic field reversal caused by the anti-phase electric
dipole coupling, the real part of the equivalent permeability of the film is negative. Therefore, the
wavelength range associated with the intensity of inverse magnetic response is tunable by varying the
size of Ag-SiO2-Ag nanosandwich structure. The equivalent electromagnetic parameters of the
Ag-SiO2-Ag nanosandwich thin film prepared by glancing angle deposition are derived from the
transmission and the reflection coefficients measured by walk-off interferometers. The measured
results indicate that film exhibit double negative properties and lead to negative values of the real parts
of equivalent refractive indices -0.854, -1.179, and -1.492 for λ = 532 nm, 639 nm, and 690 nm,
respectively. Furthermore, the real part of permeability is negatively enhanced to be -4.771 and the
maximum value of figures of merit (FOM) recorded being 6.543 for p-polarized light at λ = 690 nm.
Finally, we analyze the admittance loci for our nanosandwich thin film. This analysis can be applied to
interpret extraordinary optical properties such as negative index of refraction from Ag-SiO2-Ag
nanosandwich films.
Fabrication and Characterization II
Sculptured thin films: nanorods, nanopipes, nanosmiles
D. Gall
Show abstract
Atomic shadowing during physical vapor deposition causes exacerbated growth of surface protrusions and leads to a
chaotic 3D layer growth, which can result in the development of well-separated nanorods, nanosprings, or nanopipes,
which are surprisingly regular and have potential applications ranging from fuel cell electrodes and pressure sensors to
self-lubricating coatings and nanoactuation. Glancing angle deposition (GLAD) causes particularly strong atomic
shadowing and can be used to systematically investigate the effect of shadowing on the morphological evolution. These
extremely rough layers cannot be described as a chaotic perturbation from a flat surface. However, using a model which
describes them as a nanorod array with an average rod width that follows power law scaling results in experimental
curves where all metals converge on a single master curve which exhibits a discontinuity at 20% of the melting point,
associated with a transition from a 2D to a 3D island growth mode, and a single homologous activation energy of 2.46
for surface diffusion on curved nanorod growth fronts, which is applicable to all metals at all temperatures. Also, under
extreme shadowing conditions, the conventional structure zone model is simplified as there is a direct transition from an
underdense (zone I) to a dense (zone III) structure at ~50% of the melting point.ïýc
Electrophoretic deposition of Cu-In composite nanoparticle thin films for fabrication of CuInSe[sub]2[/sub] solar cells
Show abstract
Thin films of Cu-In composite nanoparticles were produced by electrophoretic deposition in colloidal suspensions. The
nanoparticles were prepared with high power pulsed laser ablation in liquid solvents. The nanoparticles inherited
composition (Cu/In ratio) from the target during laser ablation. The colloidal suspension was stable against
agglomeration without adding additional surfactant or dispersing agent. The success of electrophoretic deposition of the
nanoparticles was explained based on electrochemical interactions between the nanoparticles and the electrode. CuInSe2solar absorber layers were produced after annealing the thin films in selenium vapor under atmospheric pressure. Solar
cell devices were made on Mo metal sheet and Mo-coated soda-lime glass substrates with an energy conversion
efficiency of up to 3.4% under AM1.5G illumination. The results open up a new route of non-vacuum fabrication of thin
film chalcopyrite solar cells on flexible substrates with minimized chemical contamination, easy compositional control,
and high raw material utilization.ationDa
X-ray absorption fine-structure and optical studies of AlZnO nano-thin films grown on sapphire by pulsed laser deposition
Y. R. Lan,
S.-P. Liu,
C. C. Wei,
et al.
Show abstract
Al-doped ZnO can replace tin-doped indium oxide (ITO) as a good transparent conductive oxide (TCO) in LEDs and
optoelectronic applications. We investigate on nanometer scale AlZnO thin film materials epitaxied on sapphire
substrates in 350-650°C from pulsed laser deposition (PLD). Synchrotron radiation X-ray absorption fine-structure
spectroscopy on O K-edge indicates that Al-doped ZnO can not form alloy at growth temperature 350°C without Al-O
bonding feature. The Al-O transition of AZO550 is stronger than AZO650. These are correlated to Raman scattering
measurements and analyses. Al-doped ZnO grown at 350°C possesses weak/broad Raman signals indicating a poor
crystalline film. The E2 (high) mode is strong and narrow in AZO550. All these experimental results indicate that PLD
grown AlZnO film on sapphire could get a better crystalline quality at 550°C than 350°C and 650°C.
Fabrication and Characterization III
Luminescent multifunctional biocellulose membranes
J. M. A. Caiut,
H. S. Barud,
M. V. Santos,
et al.
Show abstract
Luminescent biocellulose membranes were obtained by incorporation of ethanolic solutions of the europium compounds
[Eu(BTFAC)3(H2O)2], [Eu(BTFA)3(DBSO)2], [Eu(BTFA)3(PTSO)2] and [Eu(BTFA)3(FSO)2] (BTFAC- 4,4,4-Trifluoro-1-
phenyl-1,3-butanedione DBSO- dibenzyl sulfoxide, PTSO- p-Tolyl sulfoxide and FSO- phenyl sulfoxide). Selfsustainable
semi-transparent composite membranes were obtained showing strong emission under UV exctiation. The
antenna hole played by the ligands was observed to be more efficient in the composite membranes than in the precursor
complexes which by themselves are also strong red emitter compounds. These new multifuctional membranes could find
application in different areas as phosphors and UV→Visible energy converting devices.
Chromogenic behaviours of silver containing mesoporous titania films
Show abstract
We investigate the effects of three reduction processes on the formation of silver nanoparticles in mesoporous titania
films. The later are impregnated with silver salt and then either exposed to UV laser light, chemically treated or
annealed. Depending on the reduction process, the NP are confined inside the mesopores or not, leading to different NP
size distributions and to various film colors. These TiO2/Ag nanocomposite films also exhibit different photochromic
behaviours when exposed to visible laser radiations. We characterize and interpret the color changes as well as the NP
deformation and oxidation under visible illuminations.
Electron microscopy characterization of some carbon based nanostructures with application in divertors coatings from fusion reactor
Show abstract
Nanostructured carbon materials have increasingly attracted the interest of the scientific community, because of
their fascinating physical properties and potential applications in high-tech devices. In the current ITER design, the tiles
made of carbon fiber composites (CFCs) are foreseen for the strike point zone and tungsten (W) for other parts of the
divertor region. This choice is a compromise based mainly on experience with individual materials in many different
tokamaks. Also Beryllium is the candidate material for the First Wall in ITER.
In order to prepare nanostructured carbon-tungsten nanocomposite for the divertor part in fusion applications,
the original method thermionic vacuum arc (TVA) was used in two electronic guns configuration. One of the main
advantages of this technology is the bombardment of the growing thin film just by the ions of the depositing film.
The nanostructured C-W and C-Be films were characterized by Scanning Electron Microscopy (SEM),
Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM). The C-W films were identified as a
nanocrystals complex (5 nm average diameter) surrounded by amorphous structures with a strong graphitization
tendency, allowing the creating of adherent and wear resistant films. The C-Be films are polycrystalline with mean grain
size about 15 nm. The friction coefficients (0.15 - 0.35) of the C-W coatings was decreased more than 3-5 times in
comparison with the uncoated substrates proving excellent tribological properties. C-W nanocomposites coatings were
designed to have excellent tribological properties while the structure is composed by nanocrystals complex surrounded
by amorphous structures with a strong graphitization tendency, allowing the creating of adherent and wear resistant
films.&updat
Optical investigation on plasmonic effect of the nanostructured surface plasmon resonance sensor chips fabricated by Langmuir-Blodgett technique
Show abstract
We used the Langmuir-Blodgett (LB) method for preparation of defect-free and large-area silica-nanoparticlesmonolayer
as a template for the fabrication of Au nanostructures on an Au-thinfilm for surface plasmon resonance
(SPR). The dimensions of trigonal pyramid Au nanostructures were controlled by changing the particle size of the silica
LB template. The nanostructured SPR chips provide the enhancement of sensitivity in SPR analysis compared to a
conventional SPR chip when 20 % ethanol solution was used as an analyte. We took a theoretical approach by evaluating
optical properties of the Au-nanostructures and nanostructured SPR chips in the view of plasmonic effect.
Poster Session
Tungsten nanostructured thin films obtained via HFCVD
Show abstract
By using the Hot Filament Chemical Vapor Deposition (HFCVD) technique tungsten thin films were deposited on
amorphous quartz substrates. To achieve this, a tungsten filament was heated at 1300 °C during 30 minutes maintaining
a constant pressure inside the chamber at 460 mTorr and substrate at 700 °C. Transition from tungsten oxide deposits to
tungsten thin films, by varying the substrate temperature, were characterized by means of Scanning Electron Microscope
(SEM), Atomic Force Microscope (AFM), X-Ray Diffraction and, micro-Raman spectroscopy. The SEM micrographs
reveal that the tungsten films have no more than 200 nm in thickness while XRD show evidence of the films crystallize
in the á-tungsten modification. On the other hand, AFM shows that the tungsten thin films exhibit a uniform and smooth
surface composed with semi-spherical shapes whose diameters are below than 50 nm. Furthermore, to the naked eye, the
as-deposited tungsten films exhibit a high mirror-like appearance.
Anisotropic optical property of an asymmetric bideposition Ta2O5 film: fabrication and measurement
Show abstract
To develop diverse anisotropic thin films, asymmetric bideposition technique is introduced to
fabricate tilt columnar Ta2O5 films with biaxial optical property. The asymmetric bideposition is
achieved using two different opposite deposition angles (a+,a-) and two different thicknesses of
opposite deposited subdeposits. The two sets of Ta2O5 columnar thin films associated with deposited
subdeposits (d+,d-)=(5.2,2.8) are prepared at the opposite deposition angles (a+,a-)=(70,-40), (75,-40),
(80,-40) and at the opposite deposition angles (a+,a-)=(70,-50), (75,-50), (80,-50). Columnar thin films
with various column angle and biaxial properties are measured their planar birefringence and three
principal indexes. The larger column angle leads to higher principal indices. It is demonstrated that the
asymmetric bideposition can enhance the birefringence of a tilted columnar thin film.ntut.edu.tw