Impact of contact resistance on the electrical properties of MoS₂ transistors at practical operating temperatures

• Filippo Giannazzo,
• Gabriele Fisichella,
• Aurora Piazza,
• Salvatore Di Franco,
• Giuseppe Greco,
• Simonpietro Agnello and
• Fabrizio Roccaforte

Beilstein J. Nanotechnol. 2017, 8, 254–263, doi:10.3762/bjnano.8.28

• , cm−3). According to this expression a low value of VFB,id slightly varying with the T (from −0.35 V at 298 K to −0.42 V at 273 K) would be expected for our device. The negative shift of the experimental VFB with respect to VFB,id can be accounted for by the presence of a net positive charge density

Modelling of ‘sub-atomic’ contrast resulting from back-bonding on Si(111)-7×7

• Adam Sweetman,
• Samuel P. Jarvis and
• Mohammad A. Rashid

Beilstein J. Nanotechnol. 2016, 7, 937–945, doi:10.3762/bjnano.7.85

• closely reflect the force and/or charge density associated with the molecule. In Figure 3 we compare constant height force, and Δf images acquired with different oscillation amplitudes, at different tip–sample separations. Intriguingly, the triangular shape of the adatoms is more pronounced in the force

• interpretation of features of this type requires full ab-initio modelling of the combined tip–sample system, with full consideration of the combined charge density, and the relaxation of the atomic positions, in the tip–sample junction. Left column: Experimental constant height Δf images at decreasing tip–sample

Microscopic characterization of Fe nanoparticles formed on SrTiO₃(001) and SrTiO₃(110) surfaces

• Miyoko Tanaka

Beilstein J. Nanotechnol. 2016, 7, 817–824, doi:10.3762/bjnano.7.73

• nuclei for subsequent nanoparticle growth. Adjacent nuclei growing independently may merge and grow into a larger nanoparticle with a non-equilibrium interface. Charge effects should also be considered [62][63]. Both STO(001) and STO(110) surfaces could exhibit variations of charge density associated

First-principles study of the structure of water layers on flat and stepped Pb electrodes

• Xiaohang Lin,
• Ferdinand Evers and
• Axel Groß

Beilstein J. Nanotechnol. 2016, 7, 533–543, doi:10.3762/bjnano.7.47

• make the water–water interaction stronger [15]. In order to understand the differences between the water adsorption on the terraces and the steps, we have determined the charge density difference upon water adsorption on Pb(100) and Pb(511) (Figure 4) which corresponds to the adsorption-induced charge

• terrace atoms, as confirmed by an analysis of the charge density difference upon water adsorption. The thermal stability of the water layers has been addressed by performing ab initio molecular dynamics simulations at a temperature of 140 K. The minimum-energy structure of the water layers on Pb(111) and

• ) (a), Pb(511) (b) and Pb(711) (c). Isosurface plots of charge-density differences upon water adsorption on a) Pb(100) and b) Pb(511). The plotted isosurfaces correspond to charge density with an absolute value of 0.006 e/Å2. Charge accumulation, i.e., an increase in the electron density, is plotted in

Charge and heat transport in soft nanosystems in the presence of time-dependent perturbations

• Alberto Nocera,
• Carmine Antonio Perroni,
• Vincenzo Marigliano Ramaglia and
• Vittorio Cataudella

Beilstein J. Nanotechnol. 2016, 7, 439–464, doi:10.3762/bjnano.7.39

Invariance of molecular charge transport upon changes of extended molecule size and several related issues

• Ioan Bâldea

Beilstein J. Nanotechnol. 2016, 7, 418–431, doi:10.3762/bjnano.7.37

• charge density at the ends of the extended molecule computed within the WBL does not properly evolve into that of the bulk electrodes. The rather general model Hamiltonian of Equation 9 does satisfy these conditions. Condition (i) is satisfied because the electrodes’ parameters (on-site energies μL,R and

Influence of calcium on ceramide-1-phosphate monolayers

• Joana S. L. Oliveira,
• Gerald Brezesinski,
• Alexandra Hill and
• Arne Gericke

Beilstein J. Nanotechnol. 2016, 7, 236–245, doi:10.3762/bjnano.7.22

• a condensed monolayer, while at pH 7.2 the electrostatic repulsion of the negatively charged phosphomonoester head groups becomes more important and the monolayer is in a less solid-like state. Also at pH 7.2, the monolayer has a higher charge density than on water. They also determined the pKa2 in

Mismatch detection in DNA monolayers by atomic force microscopy and electrochemical impedance spectroscopy

• Maryse D. Nkoua Ngavouka,
• Pietro Capaldo,
• Elena Ambrosetti,
• Giacinto Scoles,
• Loredana Casalis and
• Pietro Parisse

Beilstein J. Nanotechnol. 2016, 7, 220–227, doi:10.3762/bjnano.7.20

• capacitance at the interface, due to a combination of height changes, displacement of water molecules upon binding of new strands, and rearrangement of charge density, bringing to a new value for the capacitance, CdsDNA [36]. Our device can follow the variation of capacitance in real time, allowing for the

• capacitance plateau, whereas AFM was not able to directly detect a height difference. Indeed, the changes of capacitance at the functionalized electrode are the results of a combination of changes of height in the molecular case and rearrangement of charge density. The distortions on the DNA structure due to

• of the DNA layer, the other more sensitive to its charge density) let us conclude that the structural deformations related to a single mismatch have a strong influence on the charge distribution only, leaving the molecular structure not significantly affected. Schematics of the atomic force

3D solid supported inter-polyelectrolyte complexes obtained by the alternate deposition of poly(diallyldimethylammonium chloride) and poly(sodium 4-styrenesulfonate)

• Eduardo Guzmán,
• Armando Maestro,
• Sara Llamas,
• Jesús Álvarez-Rodríguez,
• Francisco Ortega,
• Ángel Maroto-Valiente and
• Ramón G. Rubio

Beilstein J. Nanotechnol. 2016, 7, 197–208, doi:10.3762/bjnano.7.18

• their role during film formation is critical for controlling the structure and physicochemical properties of the films [13]. Among the most relevant variables are the charge density of the molecules, the concentration of the solution used, ionic strength, solvent quality for the molecules, pH, and

• polyelectrolyte occurs until a certain degree of charge inversion is reached, independently of the assembly conditions. This is explained considering that the increase of the ionic strength reduces the effective charge density of the polyelectrolyte multilayers, thus the overcompensation threshold is reached for

Charge injection and transport properties of an organic light-emitting diode

• Peter Juhasz,
• Juraj Nevrela,
• Michal Micjan,
• Miroslav Novota,
• Jan Uhrik,
• Lubica Stuchlikova,
• Jan Jakabovic,
• Ladislav Harmatha and
• Martin Weis

Beilstein J. Nanotechnol. 2016, 7, 47–52, doi:10.3762/bjnano.7.5

• efficacy (60–70 lm/W), which is the current benchmark for novel light sources [4]. Organic semiconductors have zero doping level and very low intrinsic charge density, therefore all charges in OLED device are injected from the electrodes. As a result, the energy band diagram analysis plays a key role in

• characteristics. At voltages below 2 V the low charge injection region can be recognized, since the current density J follows applied voltage bias V linearly, where e·n is the charge density (e: elementary charge, n charge carrier density), μeff is the effective charge mobility, and L the organic film thickness

• -relaxation processes in OLED devices. Charge injection/transport phenomena are thermally activated processes that follow the Boltzmann distribution. The Arrhenius plots of conductivities have been used to evaluate activation energies, as shown in Figure 5a. Since the conductivity G is affected by charge

pH-Triggered release from surface-modified poly(lactic-co-glycolic acid) nanoparticles

• Manuel Häuser,
• Klaus Langer and
• Monika Schönhoff

Beilstein J. Nanotechnol. 2015, 6, 2504–2512, doi:10.3762/bjnano.6.260

• charged substrates. The most common and therefore best investigated multilayer build-up involves two oppositely charged polyelectrolytes. Weak polyelectrolytes, such as polyacrylic acid (PAA), with a pH-dependent charge density can be used to add pH-tunable properties to the nanoparticle surface to which

• , which could be attributed to successful adsorption of the cationic PEI layer. pH-Sensitivity of the PAA layer in dependence on the adsorption pH value PAA, as a weak polyelectrolyte with a charge density depending on pH, can be easily adsorbed onto positively charged substrates, such as PLGA

• nanoparticles with an adsorbed layer of PEI. In order to investigate the effect of the linear charge density of adsorbing chains on the resulting layer properties, PAA from solutions adjusted to three different pH values, respectively, was adsorbed to PLGA–PEI nanoparticles. Regarding the ionization degree, the

Electroviscous effect on fluid drag in a microchannel with large zeta potential

• Dalei Jing and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2015, 6, 2207–2216, doi:10.3762/bjnano.6.226

• molecular dynamics (MD) simulations. They found that a large surface charge density results in a smaller slip. Jing and Bhushan [13] experimentally studied the coupling relationship between the surface charge and the slip of a smooth and hydrophobic octadecyltrichlorosilane (OTS) sample immersed in

• deionized water and saline solutions using the colloidal probe atomic force microscopy technique. They also found that an increasing surface charge density results in a decreasing slip length. Thus, the coupling between the surface charge and slip should be considered when study the combined effect of EDL

• flow in the microchannel, dp/dx is the driving pressure gradient, ρe = ze(n+ − n−) is the local net charge density in the EDL, and Ex is the electrical field strength. The modified Navier–Stokes equation gives the velocity boundary conditions where b is the charge-dependent slip length. The effect of

Mapping bound plasmon propagation on a nanoscale stripe waveguide using quantum dots: influence of spacer layer thickness

• Chamanei S. Perera,
• Alison M. Funston,
• Han-Hao Cheng and
• Kristy C. Vernon

Beilstein J. Nanotechnol. 2015, 6, 2046–2051, doi:10.3762/bjnano.6.208

• are a coherent oscillation of electrons in a metal [1]. Loosely bound electrons can combine with incoming photons and propagate along the metal/dielectric interface. These charge density waves create a strong near-field [1]. There is increasing demand for high speed data communication as well as

Transformations of PTCDA structures on rutile TiO₂ induced by thermal annealing and intermolecular forces

• Szymon Godlewski,
• Jakub S. Prauzner-Bechcicki,
• Thilo Glatzel,
• Ernst Meyer and
• Marek Szymoński

Beilstein J. Nanotechnol. 2015, 6, 1498–1507, doi:10.3762/bjnano.6.155

• ) should contribute mostly to the STM appearance when imaging of empty states is performed. The charge density contour of the PTCDA LUMO orbital comprises 14 lobes located symmetrically with respect to the longer molecular axis, where the orbital wave function changes its sign. As a result, the charge

• density in the proximity of the longer axis is very low, and thus, that area does not contribute significantly to the tunnelling process. In our high-resolution measurements, a single PTCDA molecule appears as two lobes with a clear depression between them. Considering the LUMO contour, the depression

Current–voltage characteristics of manganite–titanite perovskite junctions

• Benedikt Ifland,
• Patrick Peretzki,
• Birte Kressdorf,
• Philipp Saring,
• Andreas Kelling,
• Michael Seibt and
• Christian Jooss

Beilstein J. Nanotechnol. 2015, 6, 1467–1484, doi:10.3762/bjnano.6.152

• charge density and the material structure, the concept of bending rigid electronic bands at an interface can break down because of the emergence of new types of quasiparticles and order [32]. The nature of polaron quasiparticles may change during their interfacial transfer because of the variation of the

Scalable, high performance, enzymatic cathodes based on nanoimprint lithography

• Dmitry Pankratov,
• Richard Sundberg,
• Javier Sotres,
• Dmitry B. Suyatin,
• Ivan Maximov,
• Sergey Shleev and
• Lars Montelius

Beilstein J. Nanotechnol. 2015, 6, 1377–1384, doi:10.3762/bjnano.6.142

• the experimentally measured charge (qreal) associated with the Au oxide reduction process performed by running cyclic voltammetry (Supporting Information File 1, Figure S1). A current peak related to the reduction of the Au was integrated to calculate qreal. The theoretical charge density (σt

Surface excitations in the modelling of electron transport for electron-beam-induced deposition experiments

• Francesc Salvat-Pujol,
• Roser Valentí and
• Wolfgang S. Werner

Beilstein J. Nanotechnol. 2015, 6, 1260–1267, doi:10.3762/bjnano.6.129

• . Review Inelastic collisions in the bulk of the material Energy losses of a charged projectile moving in a solid can be described accurately within the semiclassical dielectric formalism. In this approach, one assumes that the presence of the charged projectile disturbs the equilibrium charge density of

• Fourier transform of the projectile charge density ρ(r,t) = Z0eδ(r−vt), where Z0 is the projectile charge in units of the modulus of the electron charge, e, and v is the velocity of the projectile. To obtain this expression, the following approximations were considered: (1) The Coulomb gauge was adopted

• arising from a charge density induced in the bulk of the material and another one arising from a charge density induced at the surface of the material. The DIIMFP resulting from the induced electric field becomes more complicated, with two additional parametric dependencies: (1) on the depth coordinate

From lithium to sodium: cell chemistry of room temperature sodium–air and sodium–sulfur batteries

• Philipp Adelhelm,
• Pascal Hartmann,
• Conrad L. Bender,
• Martin Busche,
• Christine Eufinger and
• Juergen Janek

Beilstein J. Nanotechnol. 2015, 6, 1016–1055, doi:10.3762/bjnano.6.105

• corresponds to a larger charge density, and the lithium ion polarizes it environment stronger than the sodium ion. This causes severe differences in chemical bonding and ion mobility. The solubility of sodium and lithium compounds in solvents are different. The discharge products and/or interphases (SEI

• (if known) and the total amount of charge should be stated. Given this, the charge density (mAh/cm3) and areal capacity (mAh/cm2) can be calculated and benchmarked against commercialized LIB materials (approximately 1–4 mAh/cm2 and 350–600 mAh/cm3). A comparable problem is that the common definition

Multiscale modeling of lithium ion batteries: thermal aspects

• Arnulf Latz and
• Jochen Zausch

Beilstein J. Nanotechnol. 2015, 6, 987–1007, doi:10.3762/bjnano.6.102

• determined by Φ through Equation 10 and not by φ. It is possible to obtain the formulation in Equation 44 and Equation 45 directly from the entropy law by choosing the flux N+ and the electric current j together with the molar density c+ = ρ+/M+ =: c and the free charge density ρF = F(z+c+ + z−c−) as primary

• electric current we finally obtain the equation for the electric charge ρF, the molar concentration of positive ions c := c+ and the entropy density: The electric charge density ρF is coupled to Coulomb’s law (Equation 10) and to the pressure equation (Equation 29). The entropy production is given by The

• external surface into the host material and shielding of the charges by lattice deformations and reorganization of the electronic charge density distribution. These elementary steps were identified experimentally [62][63] for the intercalation of Li in graphite. In this still very simple model no

Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

• Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

• ] and measurements can be performed in a well-defined metal/OML/semiconductor planar configuration, which is relevant for molecular electronics devices. Admittance spectroscopy provides insights in the modulation of localized charge density and dipole reorientation in a system submitted to a time

Chains of carbon atoms: A vision or a new nanomaterial?

• Florian Banhart

Beilstein J. Nanotechnol. 2015, 6, 559–569, doi:10.3762/bjnano.6.58

• oscillations of charge density and interatomic forces, extending over longer distances along the chain. Such Friedel oscillations in one-dimensional systems decay as 1/r. Experimental observations of carbon chains The first experimental indication for the existence of carbon chains has been deduced from a

Dynamic force microscopy simulator (dForce): A tool for planning and understanding tapping and bimodal AFM experiments

• Horacio V. Guzman,
• Pablo D. Garcia and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2015, 6, 369–379, doi:10.3762/bjnano.6.36

• tip–surface charge density and σs is the sample surface charge density. Hertz contact mechanics The elastic contact between the tip and sample is usually modelled with the Hertz model [46] whereby for a spherical tip and a half-space sample the force is given by where δ is the indentation and Eeff is

Kelvin probe force microscopy in liquid using electrochemical force microscopy

• Liam Collins,
• Stephen Jesse,
• Jason I. Kilpatrick,
• Alexander Tselev,
• M. Baris Okatan,
• Sergei V. Kalinin and
• Brian J. Rodriguez

Beilstein J. Nanotechnol. 2015, 6, 201–214, doi:10.3762/bjnano.6.19

• electrostatic response, or more generally when the force experienced by the system is governed purely by the time-independent Maxwell stress tensor directly related to the charge density between probe and sample [58]. The data can be presented as an EcFM spectra representing the bias- and time-dependent for a

Exploring plasmonic coupling in hole-cap arrays

• Thomas M. Schmidt,
• Maj Frederiksen,
• Vladimir Bochenkov and
• Duncan S. Sutherland

Beilstein J. Nanotechnol. 2015, 6, 1–10, doi:10.3762/bjnano.6.1

• experimental spectra are reproduced identifying the two resonances: a low energy resonance with a relatively high intensity and a high energy but low intensity resonance. E-field intensity (|E|2/|E0|2) and charge density plots (shown in Figure 5b) confirm the low energy resonance as a dipolar mode and the high

• extinction spectra of a hole array (holes diameter 110 nm) in 20 nm thick gold film. Underneath the E-field intensity (|E|2/|E0|2) and charge density plots for the peak at 633 nm (B) and dip at 717 nm (C) is shown. The direction of the light propagation is normal to the surface and the polarization

• horizontal in the figure plane. Schematic view of the first order and second order BW-SPP’s charge oscillations for the hole arrays. A) Simulated extinction spectra of a 20 nm thick gold cap (110 nm in diameter). Underneath the E-field intensity (|E|2/|E0|2) and charge density plots for the peaks at 560 nm

Poly(styrene)/oligo(fluorene)-intercalated fluoromica hybrids: synthesis, characterization and self-assembly

• Giuseppe Leone,
• Francesco Galeotti,
• William Porzio,
• Guido Scavia,
• Luisa Barba,
• Gianmichele Arrighetti,
• Giovanni Ricci,
• Chiara Botta and
• Umberto Giovanella

Beilstein J. Nanotechnol. 2014, 5, 2450–2458, doi:10.3762/bjnano.5.254

• through a self-assembly approach. Results and Discussion Synthesis and characterization of TF-intercalated SME Hybrids Sodium-exchanged Somasif ME100 (SME) has been chosen to intercalate a fluorescent oligo(fluorene) cation (hereafter named TF) thanks to its very low iron impurities and low charge density

• area for the charge deficit layer (assuming an average layer charge density of 0.77 nm2 as reported by Choy et al. [23]). When the TF loading is increased up to 15% and 30% CEC the XRD spectra change. T15 shows two uncorrelated peaks at 2.65 and 5.85°, indicating that different intercalating

• ; therefore, considering an average layer charge density of 0.77 nm2, the area available of SME surface is oversaturated by the oligo(fluorene) cation with a loading of 30% CEC. Synthesis and characterization of PS/TF-intercalated SME hybrids Aiming to improve the processability of the TF-intercalated SME