GRAPHYNE-BASED SINGLE ELECTRON TRANSISTOR: AB INITIO ANALYSIS

NANO ◽  
2014 ◽  
Vol 09 (03) ◽  
pp. 1450032 ◽  
Author(s):  
J. V. N. SARMA ◽  
RAJIB CHOWDHURY ◽  
R. JAYAGANTHAN
Keyword(s):  
Coulomb Blockade ◽  
Density Functional ◽  
Stability Diagram ◽  
Single Electron ◽  
Present System ◽  
Single Electron Transistor ◽  
Poisson Equations ◽  
Charge Stability ◽  
Coulomb Blockade Regime ◽  
Charging Energy

The application of graphyne for a single-electron transistor (SET) that is operating in the Coulomb blockade regime is investigated in the first principles framework. Density functional theory modeling for graphyne has been used and the device environment has been described by a continuum model. The interaction between graphyne and the SET environment is treated with self-consistent Poisson equations. The charging energy as a function of gate voltage thus calculated has been used to obtain the charge stability diagram for the present system. The effect of electrode separation and the position of the molecule with respect to the dielectric on the gate coupling have been studied further. As compared with the previously studied systems on this line, graphyne has been observed to provide the gate coupling that is nearly close to that of benzene and graphene, but significantly greater than fullerene-based systems.

CHARGE STABILITY AND CONDUCTANCE ANALYSIS OF ANTHRACENE-BASED SINGLE ELECTRON TRANSISTOR

2013 ◽  
Vol 12 (06) ◽  
pp. 1350045 ◽  
Author(s):  
ANURAG SRIVASTAVA ◽  
BODDEPALLI SANTHIBHUSHAN ◽  
PANKAJ DOBWAL
Keyword(s):  
Coulomb Blockade ◽  
Density Functional ◽  
Stability Diagram ◽  
Single Electron ◽  
Single Electron Transistor ◽  
Functional Theory ◽  
Charge Stability ◽  
Anthracene Molecule ◽  
The Stability ◽  
Experimental Values

The present paper discusses the investigation of electronic properties of anthracene-based single electron transistor (SET) operating in coulomb blockade region using Density Functional Theory (DFT) based Atomistix toolkit-Virtual nanolab. The charging energies of anthracene molecule in isolated as well as electrostatic SET environments have been calculated for analyzing the stability of the molecule for different charge states. Study also includes the analysis of SET conductance dependence on source/drain and gate potentials in reference to the charge stability diagram. Our computed charging energies for anthracene in isolated environment are in good agreement with the experimental values and the proposed anthracene SET shows good switching properties in comparison to other acene series SETs.

scholarly journals An ab Initio Calculations of Single-Electron Transistor Based Single Walled Carbon Nanotube of Ultra-Small Diameter

2020 ◽  
Keyword(s):  
Carbon Nanotube ◽  
Density Functional ◽  
Energy Levels ◽  
Small Diameter ◽  
Stability Diagram ◽  
Single Electron ◽  
Single Electron Transistor ◽  
Single Walled Carbon Nanotube ◽  
Single Walled Carbon ◽  
Charge Stability

In this paper, we have investigated the charge stability diagram and conductance dependence on source drain bias and gate voltage of carbon nanotube based single electron transistor (SET) by using first principle calculations. All calculations have been executed by using ATK-VNL simulation package based on density functional theory (DFT). We have applied these calculations for carbon nanotube based SET; the nanotube has been placed just above the dielectric ( ) in between the source and drain electrodes of gold. The single walled carbon nanotube has been used in SET, which have ultra-small diameter and (4,0) configuration. The addition energy of the device has been calculated, which can be defined as the difference between the electron affinity, and ionization energies. The calculated values of energies have been found to be -10.17694 eV and -11.04034 eV for isolated phase and SET environment respectively. In electrostatic environment, the results were showing the regularization of molecular energy levels and therefore the addition energy reduced. The calculations for additional energies, variations of total energies to that of the gate voltages and charge stability diagram (CSD) have also been done in this study.

scholarly journals First-Principles Modeling of the Smallest Molecular Single Electron Transistor

2015 ◽  
Vol 2 (1) ◽  
pp. 33-39
Author(s):  
Mudassir M. Husain ◽  
Maneesh Kumar
Keyword(s):  
First Principles ◽  
Electron Tunneling ◽  
Energy Levels ◽  
Stability Diagram ◽  
Single Electron ◽  
Single Electron Transistor ◽  
Discrete Energy ◽  
Weakly Coupled ◽  
Electron Transport Properties ◽  
Charging Energy

Using first-principles method the charging energy has been calculated; of the smallest single electron transistor (SET) consisting of only two carbon atoms while operating in coulumb blockade regime. The ethyne (C2H2) molecule is acting like a quantum dot (with discrete energy levels) and is weakly coupled to the gold electrodes (continuum). The quantum effects are significant and the conduction of current takes place through incoherent method via electron tunneling. The electronic levels of the molecule determine the electron transport properties. The molecule may be in several charged states from +2 to -2. It has been observed that the HOMO-LUMO gap is strongly reduced in solid state environment with metallic electrodes, as compared to the vacuum. This reduction is attributed to the image charges generated in the source and drain electrodes. This results in strong localization of charges in the molecule, a phenomenon addressed earlier. The charging energy has been calculated in vacuum and in SET environment. The interaction between molecule and the electrodes is treated self-consistently through Poisson equation. The charge stability diagram of the smallest molecular SET has been obtained.

scholarly journals Schemes for Single Electron Transistor Based on Double Quantum Dot Islands Utilizing a Graphene Nanoscroll, Carbon Nanotube and Fullerene

Molecules ◽  
2022 ◽  
Vol 27 (1) ◽  
pp. 301
Author(s):  
Vahideh Khademhosseini ◽  
Daryoosh Dideban ◽  
Mohammad Taghi Ahmadi ◽  
Hadi Heidari
Keyword(s):  
Quantum Dot ◽  
Coulomb Blockade ◽  
Single Electron ◽  
Double Quantum ◽  
Single Electron Transistor ◽  
Multiple Quantum ◽  
Single Electrons ◽  
Stability Diagrams ◽  
Zero Current ◽  
Charge Stability

The single electron transistor (SET) is a nanoscale switching device with a simple equivalent circuit. It can work very fast as it is based on the tunneling of single electrons. Its nanostructure contains a quantum dot island whose material impacts on the device operation. Carbon allotropes such as fullerene (C60), carbon nanotubes (CNTs) and graphene nanoscrolls (GNSs) can be utilized as the quantum dot island in SETs. In this study, multiple quantum dot islands such as GNS-CNT and GNS-C60 are utilized in SET devices. The currents of two counterpart devices are modeled and analyzed. The impacts of important parameters such as temperature and applied gate voltage on the current of two SETs are investigated using proposed mathematical models. Moreover, the impacts of CNT length, fullerene diameter, GNS length, and GNS spiral length and number of turns on the SET’s current are explored. Additionally, the Coulomb blockade ranges (CB) of the two SETs are compared. The results reveal that the GNS-CNT SET has a lower Coulomb blockade range and a higher current than the GNS-C60 SET. Their charge stability diagrams indicate that the GNS-CNT SET has smaller Coulomb diamond areas, zero-current regions, and zero-conductance regions than the GNS-C60 SET.

Evaluation of Room-Temperature Performance of Ultra-Small Single-Electron Transistor-Based Analog-to-Digital Convertors

2018 ◽  
Vol 27 (14) ◽  
pp. 1850217 ◽  
Author(s):  
Mostafa Miralaie ◽  
Ali Mir
Keyword(s):  
Coulomb Blockade ◽  
Room Temperature ◽  
Periodic Oscillation ◽  
Single Electron ◽  
Single Electron Transistor ◽  
Analog To Digital ◽  
Coulomb Oscillation ◽  
Temperature Operating ◽  
Coulomb Blockade Regime ◽  
Oscillation Characteristics

In this paper, in order to analyze the performance of single-electron transistor (SET)-based analog-to-digital converter (ADC) circuits at room temperature, first, the quantum Coulomb blockade regime is explained and based on it we calculate and discuss the inherent Coulomb oscillation characteristics of room-temperature-operating SETs (or, in other words, ultra-small SETs). Then, to explain the performance of SET-based ADC structures, we explore the sensitivity of converter section of these structures to the inherent periodic oscillation characteristics. By simulating two different temperatures of 100[Formula: see text]K and 300[Formula: see text]K, we demonstrate that for proper performance of converter section of the SET-based ADCs, SETs must have inherent Coulomb oscillations with the same and high peak-to-valley current ratio (PVCR) and equal Coulomb peak spacing (i.e., equal [Formula: see text]. The Coulomb oscillation characteristics of the room-temperature-operating silicon SET show the Coulomb oscillations with unequal PVCRs and unequal Coulomb peak spacings (i.e., unequal [Formula: see text]. As a result, it can be seen that the room-temperature-operating SET-based ADCs never have a suitable output.

scholarly journals Model of a single-electron transistor based on endohedral fullerene (Sc3N)@C80

2021 ◽  
Vol 2140 (1) ◽  
pp. 012006
Author(s):  
A G Duisenova ◽  
D M Sergeyev
Keyword(s):  
Total Energy ◽  
Bias Voltage ◽  
Gate Voltage ◽  
Density Functional ◽  
Stability Diagram ◽  
Single Electron ◽  
Total Charge ◽  
Single Electron Transistor ◽  
Scandium Nitride ◽  
The Stability

Abstract In this work within the framework of the density functional theory and the method of nonequilibrium Green’s functions the dependences of the total energy of molecules C80-SET and (Sc3N)@C80 - SET on their total charge, the dependence of the total energy from the gate voltage and the stability diagram of the single-electron transistor have been determined. It is noted that for transition to switch to on mode (Sc3N)@C80-SET it is necessary to apply the gate voltage in the range from 0.019 ≤ VG ≤ 5.940 with the bias voltage -2.040 ≤ VSD ≤ 2.155 V. Considering that at values of bias voltage equal to –0.381 ≤ VSD ≤ 0.533 V there is no voltage on the substrate (VG = 0 V) and electric current does not flow. It is shown that the total energy at negative values of charge is higher than at positive charges and that the area of the Coulomb rhombus in fullerene with scandium nitride is 5.3 times larger than in “pure” fullerene.

TRANSPARENCY OF NARROW CONSTRICTIONS IN A GRAPHENE SINGLE ELECTRON TRANSISTOR

2009 ◽  
Vol 23 (12n13) ◽  
pp. 2647-2654 ◽  
Author(s):  
C. STAMPFER ◽  
E. SCHURTENBERGER ◽  
F. MOLITOR ◽  
J. GÜTTINGER ◽  
T. IHN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electric Fields ◽  
Drain Current ◽  
Single Electron ◽  
Single Electron Transistor ◽  
Perpendicular Magnetic Field ◽  
Current Saturation ◽  
Tunnel Barriers ◽  
Graphene Island ◽  
Charging Energy

We report on electronic transport experiments on a graphene single electron transistor as function of a perpendicular magnetic field. The device, which consists of a graphene island connected to source and drain electrodes via two narrow graphene constrictions is electronically characterized and the device exhibits a characteristic charging energy of approx. 3.5 meV. We investigate the homogeneity of the two graphene "tunnel" barriers connecting the single electron transistor to source and drain contacts as function of laterally applied electric fields, which are also used to electrostatically tune the overall device. Further, we focus on the barrier transparency as function of an applied perpendicular magnetic field and we find an increase of transparency for increasing magnetic field and a source-drain current saturation for magnetic fields exceeding 5 T.

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