Search results for " Thin film"
showing 10 items of 102 documents
Suspended single-electron transistors: Fabrication and measurement
2005
We have fabricated aluminum single-electron transistors in which the island is not in contact with the substrate. This new type of device, which can be called suspended single-electron transistor (SUSET), displayed well-defined I-V and dI/dV-V features typical for high-quality standard SET's.
A facile semi-open method for synthesis of non-centrosymmetric superconducting Li2(Pd,Pt)3B bulks and thin films
2010
Abstract Non-centrosymmetric superconductor Li 2 (Pd 1− x Pt x ) 3 B, x = 0–1 was synthesized from mixtures of the elements. A simple semi-open method is proposed using endings-pressed stainless steel tubes placed in a high-vacuum furnace. Heating regime employed a short-time overheating at 900 °C and a slow cooling step between T s and 550 °C within 3 h. To adequately compensate Li-losses and attain maximum critical temperature, the optimum T s and starting Li-content were found to change from 720 to 740 °C and from Li 2.4 to Li 2.6 , respectively, when x was changing from 0 to 1. It was shown that placing Li separately in the tube also produces superconducting samples, Li being supplied …
On the trade-off between processability and opto-electronic properties of single wall carbon nanotube derivatives in thin film heterojunctions
2015
A flow functionalization route has been employed to derivatize single wall carbon nanotubes (SWCNTs) by thienylphenyl groups. The SWCNT derivatives in the most soluble fraction have been characterized by thermogravimetric analysis, DLS analysis, DFT calculations, and UV-vis-NIR, microRaman and IR spectroscopies to study the degree of functionalization, the concentration of SWCNTs in solution, the dimension of the aggregates in solutions, the density of defects, and the presence of the thienylphenyl groups. Thin-film heterojunctions made of SWCNT derivatives and poly(3-hexylthiophene) (P3HT) have been prepared by various methods employing the Langmuir–Schaefer technique, spin-coating and the…
Cs0.86(NH41.14SO4Te(OH)6 in porous anodic alumina for micro fuel cell applications.
2011
Abstract Cs0.86(NH4)1.14SO4Te(OH)6 supported by anodic alumina membranes (AAMs) has been characterized for the first time in H2/O2 fuel cell. The fabricated membrane electrode assemblies are able to produce peak power densities in the range 15–30 mW cm−2 under mild conditions (room temperature, low humidity and low Pt loading) and show an increased durability with cycling with respect to previous results obtained with AAM-based fuel cell. The physico-chemical characterization of the electrolytes has been carried out through X-ray diffractometry, scanning electron microscopy and micro-raman analysis. An estimation of the composite membranes conductance under fuel cell operation has been carr…
Nanoporous alumina membranes filled with solid acid for thin film fuel cells at intermediate temperatures
2004
Thin film fuel cells have been fabricated by impregnation of inorganic porous membranes with inorganic proton conductor. Anodic alumina membranes (50 μm thick and pore diameter of 200 nm), filled with CsHSO4 salt have been used as protonic conductor in a hydrogen-oxygen fuel cell working between 423 and 443 K in dry atmosphere. Polarization curves at 433 K showing ohmic control with open circuit values near 0.8 V and short circuit current around 8 mA cm−2 have been obtained. Possible causes of degradation as well as alternative routes to overcome some of the problems encountered with this approach will be reported. Keywords: Solid acid, Anodic alumina membranes, Pore filling, Thin film fuel…
Preparation of photocatalytic nanostructured TiO2 thin films
2008
Micro/nanostructured thin films : synthesis by ALD of composites associating TiO2 inverse opals and gold nanoparticles for photocatalysis applications
2021
The aim of this work was to improve the photocatalytic properties of titanium dioxide (TiO2) thin films, a semiconductor that is widely used for photocatalysis applications, particularly for the treatment of polluted water. For this purpose, two complementary approaches were studied: increasing the surface area available for photocalatytic reactions and coupling between TiO2 and gold nanoparticles.. For the first approach, TiO2 thin films with different morphological structures were fabricated by Atomic Layer Deposition: dense and porous flat films, and inverse opals films.In order to evaluate photocatalytic activity of the different films, the degradation of methylene blue in aqueous solut…
A Compact SPICE Model for Organic TFTs and Applications to Logic Circuit Design
2016
This work introduces a compact DC model developed for organic thin film transistors (OTFTs) and its SPICE implementation. The model relies on a modified version of the gradual channel approximation that takes into account the contact effects, occurring at nonohmic metal/organic semiconductor junctions, modeling them as reverse biased Schottky diodes. The model also comprises channel length modulation and scalability of drain current with respect to channel length. To show the suitability of the model, we used it to design an inverter and a ring oscillator circuit. Furthermore, an experimental validation of the OTFTs has been done at the level of the single device as well as with a discrete-…
Monolayer and multilayer field-effect transistors based on a high-mobility n-type polymer: effect of the polymeric texture on charge transport
2012
Spin and charge currents driven by the Higgs mode in high-field superconductors
2020
The Higgs mode in superconducting materials describes slowly decaying oscillations of the order parameter amplitude. We demonstrate that in superconductors with a built-in spin-splitting field the Higgs mode is strongly coupled to the spin degrees of freedom, allowing for the generation of time-dependent spin currents. Converting such spin currents to electric signals by spin-filtering elements provides a tool for the second-harmonic generation and the electrical detection of the Higgs mode generated by the external irradiation. The nonadiabatic spin torques generated by these spin currents allow for the magnetic detection of the Higgs mode by measuring the precession of the magnetic moment…