Search results for "Volt"
showing 10 items of 2187 documents
Memory effects in MOS devices based on Si quantum dots
2003
Silicon quantum dots have been deposited on top of a 3-nm tunnel oxide by Low Pressure Chemical Vapour Deposition (LPCVD) and coated with a 7-nm Chemical Vapour Deposited (CVD) oxide. This stack was then incorporated in Metal-Oxide-Semiconductor structure and used as floating gate of a memory cell. The presence of 3 nm of tunnel oxides allows the injection of the charge by direct tunnel (DT) using low voltages for both program and erase operations. The charge stored in the quantum dots is able to produce a well-detectable flat band shift in the capacitors or, equivalently, a threshold voltage shift in the transistors. Furthermore, due to the presence of SiO 2 between the grains, the lateral…
Single cigar-shaped nanopores functionalized with amphoteric amino acid chains: experimental and theoretical characterization.
2012
We present an experimental and theoretical characterization of single cigar-shaped nanopores with pH-responsive carboxylic acid and lysine chains functionalized on the pore surface. The nanopore characterization includes (i) optical images of the nanostructure obtained by FESEM; (ii) different chemical procedures for the nanopore preparation (etching time and functionalizations; pH and electrolyte concentration of the external solution) allowing externally tunable nanopore responses monitored by the current-voltage (I-V) curves; and (iii) transport simulations obtained with a multilayer nanopore model. We show that a single, approximately symmetric nanopore can be operated as a reconfigurab…
An electrochemical route towards the fabrication of nanostructured semiconductor solar cells
2010
This work presents our preliminary results regarding an electrochemical process which allows the growth of nanostructured materials by means of nanopore templates. Also we analyze possible applications of this process to fabricate nanostructured semiconductors, such as CIGS, suitable for photovoltaic devices, and we consider the implications from the perspective of characterization techniques and device modelling when using such a technology.
Impact of contact resistance on the electrical properties of MoS
2016
Molybdenum disulphide (MoS2) is currently regarded as a promising material for the next generation of electronic and optoelectronic devices. However, several issues need to be addressed to fully exploit its potential for field effect transistor (FET) applications. In this context, the contact resistance, R C, associated with the Schottky barrier between source/drain metals and MoS2 currently represents one of the main limiting factors for suitable device performance. Furthermore, to gain a deeper understanding of MoS2 FETs under practical operating conditions, it is necessary to investigate the temperature dependence of the main electrical parameters, such as the field effect mobility (μ) a…
Evaluation of adsorption ability of Cyclodextrin-Calixarene Nanosponges towards Pb2+ ion in aqueous solution
2021
Abstract Different cyclodextrin-calixarene nanosponges (CyCaNSs) have been characterized by means of FFC-NMR relaxometry, and used as sorbents to remove Pb2+ ions from aqueous solutions. Considering that the removal treatments may involve polluted waters with different characteristics, the adsorption experiments were performed on solutions without and with the addition of background salts, under different operational conditions. The adsorption abilities and affinities of the nanosponges towards Pb2+ ions were investigated by measuring the metal ion concentration by means of Inductively Coupled Plasma Emission Spectroscopy (ICP-OES) and Differential Pulse Anodic Stripping Voltammetry (DP-ASV…
Preparation of Graphene Nanoribbons (GNRs) as an Electronic Component with the Multi-walled Carbon Nanotubes (MWCNTs)
2015
Abstract Carbon nanotubes (CNTs) have a well-defined nanostructure to exhibit high electrical conductivity and chemical stability, and have been used as an advanced material to make electrodes of super-capacitor. Graphene nanoribbons (GNRs), as manufactured by unzipping the CNTs, have more flexible adjustable electrical properties than CNTs, and are regarded an even more promising material for super-capacitor electrodes. This paper presented a series of attempts to prepare GNRs by chemically treating multi-walled carbon nanotubes (MWCNTs); this is, an Oxidation-Reduction method was tried to make GNRs by unzipping MWCNTs longitudinally. Efforts were made in various trials to find conditions …
CuZnSnSe NANOTUBES AND NANOWIRES BY TEMPLATE ELECTROSYNTHESIS
2014
In this work we present some results of an extensive investigation aimed to find suitable conditions to grow CuZnSnSe (CZTSe) nanostructures through single-step electrodeposition into the channels of polycarbonate membranes. After the optimization of several electrodeposition parameters, we have found that pulsed current deposition, between 0 and -1 mA cm-2, is the best way to obtain CZTSe nanostructures mechanically attached to the support. An interesting result concerns the effect of supporting electrolyte in the deposition bath. In fact, changing its concentration it is possible to vary morphology of nanostructures from nanotubes to nanowires. In both case uniform arrays of ordered nanos…
Negative differential resistance in carbon nanotube field-effect transistors with patterned gate oxide.
2010
We demonstrate controllable and gate-tunable negative differential resistance in carbon nanotube field-effect transistors, at room temperature and at 4.2 K. This is achieved by effectively creating quantum dots along the carbon nanotube channel by patterning the underlying, high-kappa gate oxide. The negative differential resistance feature can be modulated by both the gate and the drain-source voltage, which leads to more than 20% change of the current peak-to-valley ratio. Our approach is fully scalable and opens up a possibility for a new class of nanoscale electronic devices using negative differential resistance in their operation.
Non-Local Transport in a Multi-Wall Carbon Nanotube
2001
Non-local electric transport phenomena were observed for a multi-wall carbon nanotube. The magnetic field dependence of non-local resistance was out of phase with respect to the conventional four-probe resistance, which could be explained in terms of the Landauer-Buttiker formula. Our observations indicate that the phase coherence length of multi-wall carbon nanotube exceeds the voltage probe length of about 1.1 µm at the measured temperatures.
Electrochemical tomato (Solanum lycopersicum L.) characterisation using contact probe in situ voltammetr
2015
[EN] An in situ electrochemical contact probe methodology for characterising tomato samples is proposed. It is based on the record of the voltammetric response of antioxidant compounds when glassy carbon electrodes are inserted into the pericarp of fresh tomato specimens cut in half. The absence of pretreatment and in situ sampling avoid sample contamination and the oxidation of air-sensitive compounds thus increasing the representativity of the analytical data relative to conventional electrochemical analysis. Characteristic voltammetric responses recorded for such compounds, including rutin, chlorogenic acid, naringenin, naringenin chalcone and ascorbic acid have been obtained. A positive…