scholarly journals Transport properties of the lateral multilayer/monolayer PtSe2 diode

2021 ◽  
Author(s):  
F. zandvakili ◽  
M. Berahman
Keyword(s):  
Density Functional Theory ◽  
Green Function ◽  
Density Functional ◽  
Reverse Bias ◽  
Forward Bias ◽  
Voltage Characteristic ◽  
Density Of State ◽  
Current Voltage Characteristic ◽  
Functional Theory ◽  
Current Voltage

Abstract A heterostructure of trilayer/monolayer platinum diselenide has been introduced and further studied. Applying the non-equilibrium green function tuned with density functional theory, it has been shown that such a junction forms a diode structure. The current voltage characteristic shows proper diode characteristics in nanoscale. Using the transmission spectrum and projected density of state, we have demonstrated that in forward bias, the conduction band and the valence band are aligned. Therefore, the possibility of tunneling enhances and this leads to the increase of current while in reverse bias such a possibility does not exist. We have also investigated the atoms of the junction and have identified the effective ones in the transmission.

scholarly journals Electron and heat transport in porphyrin-based single-molecule transistors with electro-burnt graphene electrodes

2015 ◽  
Vol 6 ◽  
pp. 1413-1420 ◽  
Author(s):  
Hatef Sadeghi ◽  
Sara Sangtarash ◽  
Colin J Lambert
Keyword(s):  
Density Functional Theory ◽  
Single Molecule ◽  
Fermi Energy ◽  
Density Functional ◽  
Function Method ◽  
Voltage Characteristic ◽  
Frontier Orbitals ◽  
Current Voltage Characteristic ◽  
Functional Theory ◽  
Current Voltage

We have studied the charge and thermal transport properties of a porphyrin-based single-molecule transistor with electro-burnt graphene electrodes (EBG) using the nonequilibrium Green’s function method and density functional theory. The porphyrin-based molecule is bound to the EBG electrodes by planar aromatic anchor groups. Due to the efficient π–π overlap between the anchor groups and graphene and the location of frontier orbitals relative to the EBG Fermi energy, we predict HOMO-dominated transport. An on–off ratio as high as 150 is predicted for the device, which could be utilized with small gate voltages in the range of ±0.1 V. A positive thermopower of +280 μV/K is predicted for the device at the theoretical Fermi energy. The sign of the thermopower could be changed by tuning the Fermi energy. By gating the junction and changing the Fermi energy by +10 meV, this can be further enhanced to +475 μV/K. Although the electrodes and molecule are symmetric, the junction itself can be asymmetric due to different binding configurations at the electrodes. This can lead to rectification in the current–voltage characteristic of the junction.

Effects of different tailoring graphene electrodes on the rectification and negative differential resistance of molecular devices

2018 ◽  
Vol 32 (29) ◽  
pp. 1850323
Author(s):  
Ting Ting Zhang ◽  
Cai Juan Xia ◽  
Bo Qun Zhang ◽  
Xiao Feng Lu ◽  
Yang Liu ◽  
...  
Keyword(s):  
Electronic Transport ◽  
Negative Differential Resistance ◽  
Density Functional ◽  
Graphene Nanoribbons ◽  
Differential Resistance ◽  
Voltage Characteristic ◽  
Molecular Devices ◽  
Current Voltage Characteristic ◽  
Functional Theory ◽  
Current Voltage

The electronic transport properties of oligo p-phenylenevinylene (OPV) molecule sandwiched with symmetrical or asymmetric tailoring graphene nanoribbons (GNRs) electrodes are investigated by nonequilibrium Green’s function in combination with density functional theory. The results show that different tailored GNRs electrodes can modulate the current–voltage characteristic of molecular devices. The rectifying behavior can be observed with respect to electrodes, and the maximum rectification ratio can reach to 14.2 in the asymmetric AC–ZZ GNRs and ZZ–AC–ZZ GNRs electrodes system. In addition, the obvious negative differential resistance can be observed in the symmetrical AC-ZZ GNRs system.

scholarly journals Density functional theory study of electronic properties of Bi2Se3 and Bi2Te3

2017 ◽  
Vol 12 (3) ◽  
Author(s):  
Abdullahi Lawal ◽  
Amiruddin Shaari
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Topological Insulators ◽  
Van Der Waals Interactions ◽  
Partial Density ◽  
Total Density ◽  
Density Of State ◽  
Generalized Gradient ◽  
Linear Dispersion ◽  
Functional Theory

Topological insulators are layered materials via van der Waals interactions with hexagonal unit cell similar to that of graphene. The exciting features of Bi2Se3 and Bi2Te3 topological insulators their zero band gap surface states exhibiting linear dispersion at the Fermi energy. We present here first principles study pertaining to electronics properties of Bi2Se3 and Bi2Te3 compound with and without spin-orbit interaction using density functional theory (DFT). Total density of state (DOS), partial density of state (PDOS) and band structure where determined by Quantum-Espresso simulation package which uses plane wave basis and pseudopotential for the core electrons, while treating exchange-correlation potential with generalized gradient approximation (GGA). From our computations, the obtained results were found to be consistent with the available experimental results. 

Transition metal-containing molecular devices: controllable single-spin negative differential thermoelectric resistance effects under gate voltages

2019 ◽  
Vol 21 (9) ◽  
pp. 5243-5252 ◽  
Author(s):  
Xifeng Yang ◽  
Fangxin Tan ◽  
Yaojun Dong ◽  
Hailin Yu ◽  
Yushen Liu
Keyword(s):  
Density Functional Theory ◽  
Green Function ◽  
Transition Metal ◽  
Density Functional ◽  
Function Method ◽  
Graphene Nanoribbon ◽  
Molecular Devices ◽  
Functional Theory ◽  
Green Function Method ◽  
Single Spin

Based on the non-equilibrium Green function method combined with density functional theory, we investigate the spin-resolved transport through transition metal (TM) (= Cr, Mn, Fe and Ru)-containing molecular devices in the presence of zigzag graphene nanoribbon (ZGNR) electrodes.

The Local Structure and I-V Characteristics of Chromium Doped Semiconducting Boron Carbide

2011 ◽  
Vol 1307 ◽  
Author(s):  
Jing Liu ◽  
P. A. Dowben ◽  
Guangfu Luo ◽  
Wai-Ning Mei ◽  
Anil Kumar Rajapitamahuni ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Boron Carbide ◽  
Local Structure ◽  
Density Functional ◽  
Room Temperature ◽  
Magnetic Ordering ◽  
Computational Results ◽  
Functional Theory ◽  
Spin Configuration ◽  
Current Voltage

ABSTRACTThe local spin configuration and band structure of chromium doped boron carbide calculated by density functional theory suggests local magnetic ordering. While the long range dopant position appears random in the boron carbide semiconductor, the local position and initial empirical/computational results suggest the promise of large magneto-resistive effects. The chromium doped boron carbide thin films, fabricated by boron carbide-chromium co-deposition, were studied by current-voltage (I-V) characteristics measurements. The results provide some reason to believe that magneto-resistive effects are indeed present at room temperature.

Electronic Structure and Optical Properties of Cu-Doped SnO2

2014 ◽  
Vol 716-717 ◽  
pp. 20-23
Author(s):  
Min Xu
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Absorption Spectrum ◽  
Electronic Structure ◽  
Optical Absorption ◽  
Band Structure ◽  
Density Functional ◽  
Density Of State ◽  
Functional Theory ◽  
Reflectivity Spectrum

based on Density Functional Theory, we investigated the optical structures and the electronic properties of Cu doped SnO2with density of 12.5%, including band structure, the density of state (dos), Dielectric function and optical absorption spectrum. The results show that Fermi level access conduction band gradually with the doped density. It has enhanced the electrical and metal property of material. The peaks of reflectivity spectrum and absorption spectrum correspond density of state.

First Principles Study on Structural and Electronic Properties of LiFeSO4OH Cathode Material for Lithium Ion Batteries

2014 ◽  
Vol 510 ◽  
pp. 33-38 ◽  
Author(s):  
F.W. Badrudin ◽  
M.S.A. Rasiman ◽  
M.F.M. Taib ◽  
N.H. Hussin ◽  
O.H. Hassan ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Cathode Material ◽  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Density Of State ◽  
Functional Theory ◽  
Structural And Electronic Properties

Structural and electronic properties of a new fluorine-free cathode material of polyanionichydroxysulfates, LiFeSO4OH withcaminitestructure are studied using first principles density functional theory. From the calculated result, it reveals that antiferromagnetic configuration is more stable compared to ferromagnetic and non-magnetic configuration. Meanwhile, the density of state calculation divulges that this material exhibited large d-d type of band gap and would behave as a Mott-Hubbard insulator. Thus, this behaviour can lead to poor electronic conductivity.

A MOLECULAR DIODE BASED ON CONJUGATED CO-OLIGOMERS

2006 ◽  
Vol 05 (04n05) ◽  
pp. 535-540
Author(s):  
PING BAI ◽  
CHEE CHING CHONG ◽  
ER PING LI ◽  
ZHIKUAN CHEN
Keyword(s):  
Density Functional Theory ◽  
Spatial Orientation ◽  
First Principles ◽  
Density Functional ◽  
Infinite System ◽  
Energy Gap ◽  
Functional Theory ◽  
Molecular Diode ◽  
Current Voltage ◽  
P Type

A molecular diode based on a conjugated co-oligomer composed of p-type and n-type segments is investigated using the first principles method. The co-oligomer is connected to Au electrodes to form an Au –oligomer– Au system. The infinite system is dealt with a finite structure confined in a device region and effects from semi-infinite electrodes. Density functional theory and nonequilibrium Green's function are used to describe the device region self-consistently. The current–voltage (I–V) characteristics of the constructed system are calculated and a rectification behavior is observed. The energy gap and the spatial orientation of molecular orbitals, and the transmission functions are calculated to analyze the I–V characteristics of the molecular diode.

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