Transport Simulation of Graphene Devices with a Generic Potential in the Presence of an Orthogonal Magnetic Field.

The effect of an orthogonal magnetic field is introduced into a numerical simulator, based on the solution of the Dirac equation in the reciprocal space, for the study of transport in graphene devices consisting of armchair ribbons with a generic potential. Different approaches are proposed to reach this aim. Their efficiency and range of applicability are compared, with particular focus on the requirements in terms of model setup and on the possible numerical issues that may arise.

Effects of A Magnetic Field on the Transport and Noise Properties of a Graphene Ribbon with Antidots.

We perform a numerical simulation of the effects of an orthogonal magnetic field on charge transport and shot noise in an armchair graphene ribbon with a lattice of antidots. This study relies on our envelope-function based code, in which the presence of antidots is simulated through a nonzero mass term and the magnetic field is introduced with a proper choice of gauge for the vector potential. We observe that by increasing the magnetic field, the energy gap present with no magnetic field progressively disappears, together with features related to commensurability and quantum effects.

Low-voltage 2D materials-based printed field-effect transistors for integrated digital and analog electronics on paper.

Paper is the ideal substrate for the development of flexible and environmentally sustainable ubiquitous electronic systems, which, combined with two-dimensional materials, could be exploited in many Internet-of-Things applications, ranging from wearable electronics to smart packaging. Here we report high-performance MoS field-effect transistors on paper fabricated with a "channel array" approach, combining the advantages of two large-area techniques: chemical vapor deposition and inkjet-printing. The first allows the pre-deposition of a pattern of MoS; the second, the printing of dielectric layers, contacts, and connections to complete transistors and circuits fabrication.

Inkjet-printed graphene Hall mobility measurements and low-frequency noise characterization.

We report room temperature Hall mobility measurements, low temperature magnetoresistance analysis and low-frequency noise characterization of inkjet-printed graphene films on fused quartz and SiO/Si substrates. We found that thermal annealing in vacuum at 450 °C is a necessary step in order to stabilize the Hall voltage across the devices, allowing their electrical characterization. The printed films present a minimum sheet resistance of 23.

All-2D Material Inkjet-Printed Capacitors: Toward Fully Printed Integrated Circuits.

A well-defined insulating layer is of primary importance in the fabrication of passive ( e.g., capacitors) and active ( e.

A tight binding and [Formula: see text] study of monolayer stanene.

Stanene is a single layer of tin atoms which has been discovered as an emerging material for quantum spin Hall related applications. In this paper, we present an accurate tight-binding model for single layer stanene near the Fermi level. We parameterized the onsite and hopping energies for the nearest, second nearest, and third nearest neighbor tight-binding method, both without and with spin orbital coupling.

On current transients in MoS Field Effect Transistors.

We present an experimental investigation of slow transients in the gate and drain currents of MoS-based transistors. We focus on the measurement of both the gate and drain currents and, from the comparative analysis of the current transients, we conclude that there are at least two independent trapping mechanisms: trapping of charges in the silicon oxide substrate, occurring with time constants of the order of tens of seconds and involving charge motion orthogonal to the MoS sheet, and trapping at the channel surface, which occurs with much longer time constants, in particular when the device is in a vacuum. We observe that the presence of such slow phenomena makes it very difficult to perform reliable low-frequency noise measurements, requiring a stable and repeatable steady-state bias point condition, and may explain the sometimes contradictory results that can be found in the literature about the dependence of the flicker noise power spectral density on gate bias.

Water-based and biocompatible 2D crystal inks for all-inkjet-printed heterostructures.

Exploiting the properties of two-dimensional crystals requires a mass production method able to produce heterostructures of arbitrary complexity on any substrate. Solution processing of graphene allows simple and low-cost techniques such as inkjet printing to be used for device fabrication. However, the available printable formulations are still far from ideal as they are either based on toxic solvents, have low concentration, or require time-consuming and expensive processing.

High-performance solution of the transport problem in a graphene armchair structure with a generic potential.

We propose an efficient numerical method to study the transport properties of armchair graphene ribbons in the presence of a generic external potential. The method is based on a continuum envelope-function description with physical boundary conditions. The envelope functions are computed in the reciprocal space, and the transmission is then obtained with a recursive scattering matrix approach.

Atomistic boron-doped graphene field-effect transistors: a route toward unipolar characteristics.

We report fully quantum simulations of realistic models of boron-doped graphene-based field-effect transistors, including atomistic details based on DFT calculations. We show that the self-consistent solution of the three-dimensional (3D) Poisson and Schrödinger equations with a representation in terms of a tight-binding Hamiltonian manages to accurately reproduce the DFT results for an isolated boron-doped graphene nanoribbon. Using a 3D Poisson/Schrödinger solver within the non-equilibrium Green's function (NEGF) formalism, self-consistent calculations of the gate-screened scattering potentials induced by the boron impurities have been performed, allowing the theoretical exploration of the tunability of transistor characteristics.

Analysis of electron transfer in substituted biphenylmethane.

We present an analysis of electron transfer in a molecular structure containing two phenyl rings connected by a methylene barrier, with the addition of a donor group (NH(2)) on one ring and an acceptor group (NO(2)) on the other. Such molecules are among those currently being considered for the implementation of molecular circuits for information processing. We have performed both a study of the response of electron polarization to the application of an external electrostatic perturbation, and an analysis of the time-dependent behavior of electron transfer across the barrier.