Device simulations of a novel nanopillar-based n-CdS/p-CdTe solar cell with back contacts are carried out using the SILVACO technology computer-aided design (TCAD) device simulator. The device consists of nanopillars of CdTe coated with a very thin layer of CdS. It is shown that, for nanopillars with increasing height but given width as well as increasing width and given height, device performance

In this manuscript, a squared hollow-core photonic crystal fiber-sensor is introduced, which can be used for efficient amino acid investigations using THz waves. Amino acid identification is crucial in medical science, particularly in the drug discovery. The performance analysis has been conducted using the finite element method (FEM) based the COMSOL MULTIPHYSICS software package, and important waveguide

In this work, a multifunctional drain-engineered (DE) vertically stacked (VS) junctionless (JL) FET exhibiting device reconfigurability and its application as an inverter are proposed and simulated. The proposed DE VS JL FET consists of stacked \({n}^{+}\) and \({p}^{+}\) device layers having SiO\(_{2}\) isolation vertically, with n-drain (\({D}_n\)) and p-drain (\({D}_p\)) silicide regions connected

We develop a novel numerical method for solving the Wigner equation which does not rely upon evaluation of the Wigner kernel and utilizes quantum trajectories. This method is a generalization of the effective potential approach widely used in semiconductor TCAD tools while also solving the full Wigner equation. The method’s accuracy is demonstrated with several standard examples.

In this paper, we compare quantitatively the results obtained from the numerical simulation of current transport in polysilicon-channel MOSFETs under different modeling assumptions typically adopted to reproduce the basic physics of the devices, including the effective medium approximation and the description of polysilicon as the haphazard ensemble of monocrystalline silicon grains separated by highly

The importance of fiber Bragg gratings (FBGs) is rapidly increasing due to their wide variety of applications. We present herein a full analytical study related to a simple optimization of the performance of FBGs for sensing applications and erbium-doped fiber amplifier (EDFA) gain flattening. In sensing applications, such as strain and temperature change detection, the most important issues are the

Sb2Se3 is a nontoxic, environmentally friendly photovoltaic absorber material with both a narrow bandgap and high absorption coefficient. The optical properties of Sb2Se3 crystals are theoretically studied herein using first-principles methods. The crystal structure, electronic structure, dielectric function, and absorption coefficient are calculated. The results show that the quasi-one-dimensional

One of the important issues in the electromagnetic field is determining the location and volume of two correcting coils in the Loney’s solenoid design problem. Meta-heuristic algorithms have the ability to solve this problem efficiently. However, these algorithms suffer from getting trapped in local optima, finding global optima, and complex implementation process. The performance of meta-heuristic

The optoelectronic properties of heterocyclic BODIPY fluorophores such as 4,4-difluoro-8-(C4H3X)-4-bora-3a,4a-diaza-s-indacene (X = O, S, Se) are explored in the solid-state bulk state. The effects of elements from the chalcogenide family (O, S, and Se) on the density of states, band structure, dielectric functions, extinction coefficient, indices of refraction and reflectance, loss function, and electrical

A novel H-plane loaded on a double-staggered grating waveguide (DSGW) slow-wave structure (SWS) is proposed. The main advantage of this SWS is its high interaction impedance and low phase velocity, based on which higher output power can be expected. Electromagnetic characteristics and particle-in-cell simulations were performed using CST Microwave Studio software. The dispersion diagram of the SWS

An equivalent single-conductor model is developed for all possible structures of mixed carbon nanotube bundle interconnects at the 14-nm technology node. The results are analyzed by including the effect of scattering caused by the surface roughness of the dielectric substrate material in the temperature range from 300 to 500 K. Widely used dielectrics such as silicon dioxide (SiO2), boron nitride (BN)

We propose a parasitic BJT-based zero capacitor random access memory (Z-RAM) cell suitable for stand-alone memory applications. In this Z-RAM cell, high-bandgap TiO\(_2\) is used as the source/drain material and silicon as the channel of an n-channel fully depleted silicon-on-insulator MOSFET. Using well-calibrated TCAD simulations, we demonstrate the programming of the proposed Z-RAM cell at low drain

In this paper, a new method for implementing all two-input logic gates on an identical single-stage structure is proposed. We have used unique characteristics of single-electron transistors, which have periodic output–input relation, to design the gates and implement all two-input logic gates (symmetric/non-symmetric, monotonic/non-monotonic) by a single-stage design including only one single-electron

Organic field effect transistors (OFETs) in parallel and series circuit configurations are simulated and tested for gas sensing activity. The devices are based on PQT12 and PQTS12 organic semiconductor thin films. A two-dimensional finite element simulation methodology is implemented. It is assumed that traps due to defects and grain boundaries are uniformly distributed throughout the semiconductor

The continuous miniaturization of very large-scale integration devices impacts the performance of integrated circuits. The performance of existing interconnect materials such as copper has become saturated beyond the deep-submicron technology node, motivating the search for new interconnect materials that could be efficiently employed in such circuits. In this study, a temperature-dependent analysis

In the twenty-first century, graphene is widely used in wireless communication, especially in terahertz applications because of its amazing electrical, mechanical, and optical properties. This paper presents a graphene-based microstrip patch antenna at 0.72 THz resonant frequency for wireless communication. The proposed antenna shows 37.50% impedance bandwidth ranging from 0.53 to 0.84 THz at the center

Strain is one of the conventional methods used to enhance the mobility of carriers in metal–oxide–semiconductor field-effect transistors (MOSFETs). The strain is generated due to the lattice mismatch between the thin Si layer and underlying SiGe layers and reduces the effective mass of holes and inter-subband scattering. A compact model for such devices is essential to promote the design of very large-scale

The performance of a group III–V material quantum dot (QD) nanostructure memory is investigated using a self-consistent Schrödinger solver, eight-band k·p model, and carrier dynamics modelling. This model is used to explore the information loss due to the carrier emission rate in the QDs as a function of temperature, size and confinement potential. The results reveal the dominant emission mechanisms

As short-channel effects (SCEs) are a major issue in the nanoscale regime, investigation of the subthreshold behaviour of nanometer-scale devices is critical. Here, we have developed an analytical model for a cylindrical gate junctionless accumulation-mode MOSFET (Cyl-JLAM MOSFET) to analyse its behaviour in the subthreshold region. The two-dimensional Poisson equation is solved to develop the analytical

An all-optical pseudo-random binary sequence (PRBS) generator is designed and simulated employing micro-ring resonators (MRRs) as the core technology. The PRBS generator consists of serially connected D flip-flops realized with double-bus MRR-based switches that exploit two-photon absorption induced in a pump-probe configuration, and of a MRR-based feedback XOR gate whose design is simpler than previously

A tunable ultra-wideband metamaterial absorber based on graphene is presented herein. Its absorption exceeds 90% from 1.57 to 8.46 GHz when the Fermi level of the graphene is 0.7 eV, and it can be tuned by changing the bias voltage applied on the graphene. To explore the mechanism of its wideband absorption and tunability, the surface current of the metamaterial absorber at given absorption frequency

Currently, gallium nitride (GaN) on silicon (Si) high-electron-mobility transistors (HEMT) are a promising candidate for designing improved power electronic circuits. The lattice mismatch between GaN and Si induces buffer/substrate leakage currents that impact the performance of the device. In this paper, four different model topologies have been demonstrated to simulate the buffer/substrate loading

A theoretical model for GaAs-based solar cells with PIN structure is proposed herein. The effect of varying key parameters on the conversion efficiency is investigated. The simulations are performed using COMSOL Multiphysics software. The mobilities of electrons and holes are varied in combination with the lifetime (LT). As a result, a maximum efficiency of 10.81% is achieved by setting the electron

Charge-transport models are usually developed by first finding an appropriate density of states (DOS) which is extracted from experimental data. For organic materials, two of the more common ones include the Gaussian density of states and the exponential density of states (EDOS). This article will focus on the latter. Charge-transport models which employ an EDOS have been extensively researched, and

SPICE models are constructed for memristive devices to form associated biophysical neuron circuit models such as the Hodgkin–Huxley (HH) type II excitability neuron circuit model, the HH type III excitability neuron circuit model, the simplified HH neuron circuit model, the Morris–Lecar neuron circuit model, and the memristive based direct-current (DC) circuit model. Rigorous nonlinear circuit-theoretic

A dual narrow band perfect THz absorber is presented in this work. The structure includes three layers of graphene ribbons, disks, and sheet on the TOPAS dielectric layer while a golden plate is placed at the bottom to act as a fully reflecting mirror against THz waves. According to the simulations, the device is robust enough to show independent operation versus layers thicknesses variations, chemical

While two-dimensional (2D) materials have emerged as a new platform for nanoelectronic devices with improved electronic, optical, and thermal properties, and their heightened sensitivity to electrostatic and mechanical interactions with their environment has proved to be a bottleneck. Few-layer (FL) 2D devices retain the desirable thinness of their monolayer cousins while boosting carrier mobility

The analog/radiofrequency (RF) performance of a strained-silicon (s-Si) graded-channel dual-material double gate (GC-DMDG) metal–oxide–semiconductor field-effect transistor (MOSFET) with interface charges is investigated by using Sentaurus technology computer-aided design (TCAD) software. The analog/RF figures of merit of the proposed s-Si GC-DMDG MOSFET, including the intrinsic voltage gain, transconductance

We evaluate the eigenvalues of a type of one-dimensional PT-symmetric fractional Schrödinger equation with multiple quantum wells potential profile. By using a finite-difference scheme, we solve the fractional Schrödinger equation and present the algorithm. We study the effects of different parameters on the pairwise coalescence of eigenvalues. We show that by using the mentioned parameters, we can

In this paper the iterative rigorous approach is applied flexibly to complex Hilbert filters using structured computational grids. The wave concept iterative process (WCIP) is reviewed, focusing on their fundamental conception and simple algorithm, with the presence of defected ground structure (DGS) appearing as Hilbert curve ring (HCR) cells. The selected studied filters have shown increasing levels

Two new vertical resonant tunneling devices (RTDs) of different sizes are proposed herein to achieve negative differential resistance with enhanced tunneling and peak-to-valley ratio (PVR) stability. The proposed structures are of the form n+–p−–p+ (S2) and n+–[p−–n+]–p−–p+ (S1) with different electrodes made of parallel graphene nanoribbon and graphene sheet (S2) or bilayer graphene (S1). The results

A strained Ge1−x−ySixSny/Ge1−a−bSiaSnb direct type II staggered heterojunction n-channel tunneling field-effect transistor (FET) with a dual-material double gate is proposed herein. A high-K gate dielectric is used to improve the overall device performance. The energy bandgap for strained Ge1−x−ySixSny grown on a relaxed Ge1−a−bSiaSnb layer is determined using the generalized approach of Menendez and

A systematic theoretical investigation is carried out on the possible piezoelectric effect in the half-Heusler FeVX (X = P, As, Sb) compounds crystallizing in the cubic MgAgAs-type structure C1b by combining density functional theory (DFT) and perturbation theory (DFPT) based on the pseudopotential plane wave (PP-PW) method implemented in the ABINIT code. The ground-state properties such as the lattice

A new compact model for HfO2-based ferroelectric tunnel junction (FTJ) memristors is constructed based on detailed physical modeling using calibrated TCAD simulations. A multi-domain configuration of the ferroelectric material is demonstrated to produce quasi-continuous conductance of the FTJ. This behavior is demonstrated to enable a robust spike-timing-dependent plasticity-type learning capability

Over the last few years, ab initio methods have become an increasingly popular tool to evaluate intrinsic carrier transport properties in 2D semiconductors. The lack of experimental information, and the progress made in the development of DFT tools to evaluate electronic band structures, phonon dispersions, and electron–phonon scattering matrix-elements, have made them a favored choice. However, a

The variability of switching parameters in redox-based resistive switching RAM (ReRAM) devices is investigated by a 3D kinetic Monte Carlo approach. This physics-based model can simulate the filamentary resistive switching in the electroforming, SET and RESET processes and captures their key features. It allows to predict the impact of the forming and switching conditions on the fluctuations of key

Abstract Monolayer silicene and germanene have received intensive attention due to their good compatibility with current Si-based electronics. However, the lack of a bandgap severely limits their applications in complex electronic circuits. To overcome this obstacle, we build Si1−xGex superlattices (SLs) and further cleave them into nanoribbons to tune the electrical properties of silicene and germanene

Numerical solutions of low-frequency electromagnetic problems are not a simple task, due to the inherent nature of their electrically small structures. The wavelength is very small relative to the size of the objects considered in these problems. Therefore, extremely fine meshes have to be used in the numerical solutions to perform accurate geometrical modeling of the scatterers and/or antennas. This

Energy harvesting using triboelectric nanogenerators (TENGs) is an effective strategy to supply power to microelectronics, the Internet of Things, etc. Generally, the output performance of a triboelectric nanogenerator is limited by the breakdown of air. Hence, we systematically investigate a TENG operating in the contact-separation mode and single-electrode mode from the perspective of the electric

A new analytical model for the current–voltage characteristic of a resonant tunneling diode (RTD) is presented herein, being derived from the basic integral of the Tsu–Esaki equation. The model is physics based and developed as a function of material parameters such as the effective mass, barrier heights, and Fermi levels as well as geometrical parameters such as the barrier height and well width.

Hole-doping of GaX, InX (X = S or Se) and SnO monolayers is predicted to induce a stable ferromagnetic order in these two-dimensional materials, making them potentially interesting for nanoscaled spintronic devices. Ferromagnetism in these materials arises from their peculiar Mexican-hat valence band edge structure, which leads to a Stoner instability. We discuss here the results from first-principles

Intercalation doping is emerging as a prospective solution to enhance the performance of graphene nanoribbon interconnects. In this paper, the radio frequency (RF) analysis of stage-2 arsenic pentafluoride- and lithium-doped multilayer graphene nanoribbons (MLGNRs) has been carried out for global-level interconnects in terms of skin depth, surface impedance, critical ratio (CR), transfer gain, and

This paper presents a review on the development of parasitic-capacitance modeling for metal–oxide–semiconductor field-effect transistors (MOSFETs), covering models developed for the simple parallel-plate capacitance and the nonplanar and coplanar plate capacitances required for the intrinsic and extrinsic part of such devices. A comparative study of various extrinsic capacitance models with respect

The potential of AlGaN-based ultrawide-bandgap high-electron-mobility transistors (HEMTs) with high (> 60%) Al composition for use in high-power switching applications is studied. The devices are simulated with a gate length of 2 µm, and their figures of merit are evaluated as functions of the gate-to-drain distance, operating temperature, and different substrates. At room temperature (RT), the maximum

AbstractIn this research, using nonequilibrium green’s function integrated with density functional theory, we investigate the electronic transport properties of a β-diketone (2,6-dimethyl-3,5-heptanedione) molecular wire induced by hydrogen transfer. The title molecule can be converted between two enol and keto forms. The electronic transmission factors, spatial spreading of molecular projected self-consistent

A distinctive charge plasma approach is used to propose a novel dual-metal-gate (DMG) recessed-source/drain dopingless junctionless transistor (Re S/D DLJLT) in which the source/drain (S/D) series resistance is reduced without any increment of the gate-to-drain Miller capacitance. In this device, the charge plasma approach is applied to induce an N+ (virtually doped) S/D region by using metals with

Thermal transport in single-layer MoS2 nanoribbons (SLMOSNRs) has been comprehensively studied using equilibrium molecular dynamics (EMD) simulations based on the Green–Kubo formulation. The room-temperature thermal conductivity of a pristine ~ 10 nm × 4 nm zigzag MoS2 nanoribbon is computed to be ~ 117 W m−1 K−1 using the Stillinger–Weber (SW) interatomic potential. The thermal conductivity is also

Field-effect transistor (FET)-based biosensors with stacked gate oxides provide low leakage current and high sensitivity. However, an undesirable interfacial layer of silicate and silicon dioxide is formed in between the stacked oxides. In this paper, an underlap silicon-on-nothing FET-based biosensor with high-K gate oxide is presented for the detection of charged biomolecules, thereby removing the

Graphene nanoribbons (GNRs) are a good replacement material for silicon to overcome short-channel effects in nanoscale devices. However, with continuous technology scaling, the variability of device parameters also increases. Indeed, process, voltage, and temperature (PVT) variations affect the performance of GNR devices because of their small size. Moreover, the bandgap of GNRs is strongly affected

The aim of this paper is to present a flexible and open-source multi-scale simulation software which has been developed by the Device Modelling Group at the University of Glasgow to study the charge transport in contemporary ultra-scaled Nano-CMOS devices. The name of this new simulation environment is Nano-electronic Simulation Software (NESS). Overall NESS is designed to be flexible, easy to use

Device reconfigurability refers to the ability to choose N or P type for the same structure. Such reconfigurable operation is demonstrated herein for a silicon nanotube (SiNT) structure using three-dimensional (3D) technology computer-aided design (TCAD) numerical simulations. The reconfigurable field-effect transistor (RFET) can exhibit N- or P-type operation via the application of an appropriate

Memristor devices are crucial for developing neuromorphic computers and next-generation memory technologies. In this work, we provide a comprehensive modelling tool for simulating static DC reading operations of memristor crossbar arrays that use passive selectors with matrix algebra in MATLAB. The software tool was parallel coded and optimised to run with personal computers and distributed computer

Graphyne sheets and nanotubes (GyNTs) are known as novel low-dimensional, i.e., two-dimensional (2D) and one-dimensional (1D), semiconducting carbon allotropes that can be used in nanoelectronics and therefore merit fundamental investigation. Among such materials, attention is currently focused on γ-graphyne-1, a member of the graphyne family that exhibits a maximum cohesive energy of −8.37 eV and

We present an electrothermal drift–diffusion model for organic semiconductor devices with Gauss–Fermi statistics and positive temperature feedback for the charge carrier mobilities. We apply temperature-dependent Ohmic contact boundary conditions for the electrostatic potential and discretize the system by a finite volume based generalized Scharfetter–Gummel scheme. Using path-following techniques

In this work, we investigated the feasibility of using a microstrip sensor to monitor milk quality. The proposed microstrip sensor is composed of two symmetrical and independent rectangular microstrip patches. This method is based on a shift in the resonance frequency of the microstrip resonator caused by a change in the dielectric constant of the analysed milk. Simulations and measurements were performed

The quantum-dot cellular automata (QCA) computing paradigm is used to implement Rule 110, a unique one-dimensional cellular automata (CA) that has been proven to be Turing complete. A Turing complete architecture is capable of universal computing, which means that it could be used to implement any arbitrary computation. The optimized design of a single Rule 110 cell is presented, first using Boolean

First-principles calculations based on the full-potential linear augmented plane wave approach are applied herein to investigate the electronic, optical, and electrical properties of intrinsic point defects in cubic ZrO2. The exchange–correlation potential is treated using the recent modified Becke–Johnson potential (TB-mBJ) proposed by Tran and Blaha in addition to the generalized gradient approximation

This paper presents the design of a bioinspired synaptic integrated circuit, which takes into account the interactions of astrocyte in a tripartite synapse. These interactions result in activation of Ca2+ ion waves through fast and slow activation pathways which affect the synapse and postsynaptic neuron. The circuit has been implemented in TSMC 65-nm CMOS technology with 1.2 V supply voltage. Dynamic

The effects of lead positions and lead-ring coupling regimes are investigated for spin-related transport through a two-dimensional network of quantum nanorings (2DNQRs) considering Rashba spin–orbit interaction (RSOI) and magnetic flux. A matrix representation of the transmission and reflection coefficients through a single ring connected to the arbitrary number of leads has been introduced. As a specific

This paper presents an optimum design of an ultra-wideband (UWB) 2.5–10.5-GHz low-noise amplifier (LNA) in 180-nm and 65-nm radiofrequency (RF)-complementary metal–oxide–semiconductor (CMOS) technology. A novel input matching network employing resistive–inductive feedback and a noise-canceling technique is proposed to achieve broadband matching as well as a low noise figure (NF). Moreover, a current-reused