Optical Characterization of Si Nanowires: Dependence with Substrate Orientation and Light Polarization

2014 ◽  
Vol 1666 ◽  
Author(s):  
Juan A. Badán ◽  
Ricardo E. Marotti ◽  
Enrique A. Dalchiele ◽  
Daniel Ariosa ◽  
Francisco Martín ◽  
...  
Keyword(s):  
Self Assembly ◽  
Diffuse Reflectance ◽  
Incident Light ◽  
Light Polarization ◽  
Nanowire Arrays ◽  
Angle Of Incidence ◽  
Interference Effects ◽  
Si Nanowires ◽  
Total Reflectance

ABSTRACTOptical properties of Si nanowire arrays (SiNWs) prepared on p-doped Si(111) and Si(100) substrates are studied. The SiNWs were synthesized by self-assembly electroless metal deposition nanoelectrochemistry in an ionic silver HF solution through selective etching. Total reflectance (Rt) and total diffuse reflectance (Rdt) of SiNWs change drastically in comparison to polished Si. To understand these changes diffuse reflectance (Rd) with polarized incident light was studied. For samples prepared on Si(111), the wavelength integrated Rd (wIRd) shows maxima at certain angle of incidence θ and it does not depend on light polarization. Moreover, Rdt of SiNWs prepared on Si(111) can be modeled as an ensemble of diffuse reflectors. For samples prepared on Si(100) wIRd increases with θ, being greater when the light electric field is parallel to the plane of incidence. Also, Rd spectra show structures due to interference effects. For these reasons SiNWs prepared on Si(100) can be considered as a thin film whose refractive index depends on light polarization.

Facile 3D integration of Si nanowires on Bosch-etched sidewalls for stacked channel transistors

Nanoscale ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 2787-2792 ◽  
Author(s):  
Ruijin Hu ◽  
Haiguang Ma ◽  
Han Yin ◽  
Jun Xu ◽  
Kunji Chen ◽  
...  
Keyword(s):  
Self Assembly ◽  
High Performance ◽  
Nanowire Arrays ◽  
Si Nanowires ◽  
3D Integration ◽  
Si Nanowire

3D integration of stacked Si nanowire arrays via a self assembly growth on Bosch-etched sidewalls and a successful demonstration of high performance staked channel transistors with an impressive on/off current >107.

scholarly journals Polarization Sensitive Reflection and Dielectric Spectra in GaSe Thin Films

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Hazem K. Khanfar ◽  
Atef A. Qasrawi
Keyword(s):  
Thin Films ◽  
Incident Light ◽  
Incident Beam ◽  
Light Polarization ◽  
Angle Of Incidence ◽  
Reflected Waves ◽  
Dielectric Spectra ◽  
Polarization Effects ◽  
Polarized Waves ◽  
Incident Light Wavelength

The light polarization effects on the optical reflective and dielectric spectra of GaSe thin films are studied in the incident light wavelength range of 200–1100 nm. In this range of measurement, the angle of incidence (θi) of light was varied between 30° and 80°. In addition, at θi of 30° the light polarizing angle (δ) was altered in the range of 0–90°. Regardless of the value of λ, for all θi≻65°, the total reflectance sharply decreased with increasing θi. In addition, when θi is fixed at 30° and δ was varied, the amplitudes ratio of the polarized waves exhibits a resonance-antiresonance phenomenon at a wavelength that coincides with the film’s thickness (800 nm). This behavior was assigned to the coupled interference between incident and reflected waves and to the strong absorption effects. Two main resonance peaks are observed as response to s-polarized and normal incident beam: one is at ~540 (556 nm) and the other at ~420 THz (714 nm). The dielectric constant of the GaSe films exhibits anisotropic characteristics that nominate it for use as multipurpose optoelectronic devices.

scholarly journals Electrochemical Properties of Lipid Membranes Self-Assembled from Bicelles

Membranes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Damian Dziubak ◽  
Kamil Strzelak ◽  
Slawomir Sek
Keyword(s):  
Electrochemical Properties ◽  
Self Assembly ◽  
Lipid Membranes ◽  
Lipid Membrane ◽  
Membrane Resistance ◽  
Electrochemical Characteristics ◽  
Freeze Thaw ◽  
Lipid Films ◽  
Supported Lipid Membranes

Supported lipid membranes are widely used platforms which serve as simplified models of cell membranes. Among numerous methods used for preparation of planar lipid films, self-assembly of bicelles appears to be promising strategy. Therefore, in this paper we have examined the mechanism of formation and the electrochemical properties of lipid films deposited onto thioglucose-modified gold electrodes from bicellar mixtures. It was found that adsorption of the bicelles occurs by replacement of interfacial water and it leads to formation of a double bilayer structure on the electrode surface. The resulting lipid assembly contains numerous defects and pinholes which affect the permeability of the membrane for ions and water. Significant improvement in morphology and electrochemical characteristics is achieved upon freeze–thaw treatment of the deposited membrane. The lipid assembly is rearranged to single bilayer configuration with locally occurring patches of the second bilayer, and the number of pinholes is substantially decreased. Electrochemical characterization of the lipid membrane after freeze–thaw treatment demonstrated that its permeability for ions and water is significantly reduced, which was manifested by the relatively high value of the membrane resistance.

scholarly journals Electrospun Membranes Based on Polycaprolactone, Nano-Hydroxyapatite and Metronidazole

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 931
Author(s):  
Ioana-Codruţa Mirică ◽  
Gabriel Furtos ◽  
Ondine Lucaciu ◽  
Petru Pascuta ◽  
Mihaela Vlassa ◽  
...  
Keyword(s):  
Fiber Diameter ◽  
Maximum Load ◽  
Guided Bone Regeneration ◽  
Attenuated Total Reflectance ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Total Reflectance ◽  
X Ray ◽  
Electrospun Membranes

The aim of this research was to develop new electrospun membranes (EMs) based on polycaprolactone (PCL) with or without metronidazole (MET)/nano-hydroxyapatite (nHAP) content. New nHAP with a mean diameter of 34 nm in length was synthesized. X-ray diffraction (XRD) and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) were used for structural characterization of precursors and EMs. The highest mechanical properties (the force at maximum load, Young’s modulus and tensile strength) were found for the PCL membranes, and these properties decreased for the other samples in the following order: 95% PCL + 5% nHAP > 80% PCL + 20% MET > 75% PCL + 5% nHAP + 20% MET. The stiffness increased with the addition of 5 wt.% nHAP. The SEM images of EMs showed randomly oriented bead-free fibers that generated a porous structure with interconnected macropores. The fiber diameter showed values between 2 and 16 µm. The fiber diameter increased with the addition of nHAP filler and decreased when MET was added. New EMs with nHAP and MET could be promising materials for guided bone regeneration or tissue engineering.

scholarly journals Optically transparent vertical silicon nanowire arrays for live-cell imaging

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Roey Elnathan ◽  
Andrew W. Holle ◽  
Jennifer Young ◽  
Marina A. George ◽  
Omri Heifler ◽  
...  
Keyword(s):  
High Efficiency ◽  
Silicon Nanowire ◽  
Live Cell ◽  
Si Nanowires ◽  
Contrast Imaging ◽  
Silicon Nanowire Arrays ◽  
Transparent Substrate ◽  
Optically Transparent ◽  
Vertically Aligned

AbstractProgrammable nano-bio interfaces driven by tuneable vertically configured nanostructures have recently emerged as a powerful tool for cellular manipulations and interrogations. Such interfaces have strong potential for ground-breaking advances, particularly in cellular nanobiotechnology and mechanobiology. However, the opaque nature of many nanostructured surfaces makes non-destructive, live-cell characterization of cellular behavior on vertically aligned nanostructures challenging to observe. Here, a new nanofabrication route is proposed that enables harvesting of vertically aligned silicon (Si) nanowires and their subsequent transfer onto an optically transparent substrate, with high efficiency and without artefacts. We demonstrate the potential of this route for efficient live-cell phase contrast imaging and subsequent characterization of cells growing on vertically aligned Si nanowires. This approach provides the first opportunity to understand dynamic cellular responses to a cell-nanowire interface, and thus has the potential to inform the design of future nanoscale cellular manipulation technologies.

2D Self-assembly and Electronic Characterization of Oxygen-Boron-Oxygen-Doped Chiral Graphene Nanoribbons

2021 ◽  
Author(s):  
Lei Jin ◽  
Nerea Bilbao ◽  
Yang Lv ◽  
Xiao-Ye Wang ◽  
Soltani Paniz ◽  
...  
Keyword(s):  
Edge Effects ◽  
Self Assembly ◽  
Quantum Confinement ◽  
Graphene Nanoribbons ◽  
One Dimensional ◽  
The Past ◽  
Different Types

Graphene nanoribbons (GNRs), quasi-one-dimensional strips of graphene, exhibit a nonzero bandgap due to quantum confinement and edge effects. In the past decade, different types of GNRs with atomically precise structures...

Optical characterization of a radiochromic film by total reflectance and transmittance measurements

2004 ◽  
Vol 31 (7) ◽  
pp. 2147-2154 ◽  
Author(s):  
Franco Fusi ◽  
Luca Mercatelli ◽  
Giacomo Marconi ◽  
Giacomo Cuttone ◽  
Giovanni Romano
Keyword(s):  
Optical Characterization ◽  
Radiochromic Film ◽  
Total Reflectance
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