scholarly journals Calculation of CO adsorption capacity of single iron(II)- porphyrin and related electron transfer behavior by DFT theory

2020 ◽  
Author(s):  
Placido G. Mineo
Keyword(s):  
Density Functional ◽  
Co Adsorption ◽  
Molecular Wires ◽  
Molecular Wire ◽  
Dft Theory ◽  
Functional Theory ◽  
Current Voltage ◽  
End Groups ◽  
Transfer Behavior ◽  
Current Voltage Characteristics

The effect of CO adsorption on the electron transport behavior of single iron(II)-porphyrin molecular wire with sulfur end groups bonded to two gold electrodes isinvestigated using nonequilibrium Green's function formalism combined with firstprinciples density functional theory. The current-voltage characteristics of the singleFe-porphyrin molecular wires with and without CO adsorption are calculated. Theresults demonstrate that Fe-porphyrin molecular wire shows a negative differentialresistance (NDR) at 2.0 V

The switching behaviors induced by torsion angle in a diblock co-oligomer molecule with tailoring graphene nanoribbon electrodes

2018 ◽  
Vol 32 (04) ◽  
pp. 1850036 ◽  
Author(s):  
Aiyun Yang ◽  
Caijuan Xia ◽  
Boqun Zhang ◽  
Jun Wang ◽  
Yaoheng Su ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electronic Transport ◽  
Torsion Angle ◽  
Density Functional ◽  
Graphene Nanoribbon ◽  
Molecular Device ◽  
Functional Theory ◽  
Electronic Transport Properties ◽  
Current Voltage ◽  
Current Voltage Characteristics

By applying first-principles method based on density functional theory combined with nonequilibrium Green’s function, we investigate the effect of torsion angle on the electronic transport properties in dipyrimidinyl–diphenyl co-oligomer molecular device with tailoring graphene nanoribbon electrodes. The results show that the torsion angle plays an important role on the electronic transport properties of the molecular device. When the torsion angle rotates from 0[Formula: see text] to 90[Formula: see text], the molecular devices exhibit very different current–voltage characteristics which can realize the on and off states of the molecular switch.

scholarly journals Current–voltage characteristics of borophene and borophane sheets

2017 ◽  
Vol 19 (32) ◽  
pp. 21461-21466 ◽  
Author(s):  
Sahar Izadi Vishkayi ◽  
Meysam Bagheri Tagani
Keyword(s):  
Density Functional Theory ◽  
Green's Function ◽  
Density Functional ◽  
Theoretical Research ◽  
Functional Theory ◽  
Nonequilibrium Green's Function ◽  
Function Formalism ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Green's Function Formalism

Motivated by recent experimental and theoretical research on a monolayer of boron atoms, borophene, the current–voltage characteristics of three different borophene sheets, 2Pmmn, 8Pmmn, and 8Pmmm, are calculated using density functional theory combined with the nonequilibrium Green’s function formalism.

scholarly journals A new photodetector structure based on graphene nanomeshes: an ab initio study

2020 ◽  
Vol 11 ◽  
pp. 1036-1044
Author(s):  
Babak Sakkaki ◽  
Hassan Rasooli Saghai ◽  
Ghafar Darvish ◽  
Mehdi Khatir
Keyword(s):  
Infrared Detectors ◽  
Density Functional ◽  
Tight Binding ◽  
Optical Devices ◽  
Functional Theory ◽  
Semiconducting Properties ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
Non Equilibrium Green’S Function ◽  
Insight Into

Recent experiments suggest graphene-based materials as candidates in future electronic and optoelectronic devices. In this paper, we propose to investigate new photodetectors based on graphene nanomeshes (GNMs). Density functional theory (DFT) calculations are performed to gain insight into electronic and optical characteristics of various GNM structures. To investigate the device-level properties of GNMs, their current–voltage characteristics are explored by DFT-based tight-binding (DFTB) in combination with non-equilibrium Green’s function (NEGF) methods. Band structure analysis shows that GNMs have both metallic and semiconducting properties depending on the arrangements of perforations. Also, absorption spectrum analysis indicates attractive infrared peaks for GNMs with semiconducting characteristics, making them better photodetectors than graphene nanoribbon (GNR)-based alternatives. The results suggest that GNMs can be potentially used in mid-infrared detectors with specific detectivity values that are 100-fold that of graphene-based devices and 1000-fold that of GNR-based devices. Hence, the special properties of graphene combined with the quantum feathers of the perforation makes it suitable for optical devices.

Effect of length and negative differential resistance behavior in conjugated molecular wire tetrathiafulvalene devices

2015 ◽  
Vol 29 (20) ◽  
pp. 1550106 ◽  
Author(s):  
Xiaojiao Zhang ◽  
Keqiu Chen ◽  
Mengqiu Long ◽  
Jun He ◽  
Yongli Gao
Keyword(s):  
Electronic Transport ◽  
Negative Differential Resistance ◽  
Density Functional ◽  
Differential Resistance ◽  
Molecular Devices ◽  
Molecular Wire ◽  
Length Effect ◽  
Functional Theory ◽  
Current Voltage ◽  
The Density Functional Theory

The electronic transport properties of molecular devices constructed by conjugated molecular wire tetrathiafulvalene (TTF) have been studied by applying nonequilibrium Green’s functions in combination with the density-functional theory. Two molecular junctions with different wire lengths have been considered. The results show that the current–voltage curves of TTF devices can be modulated by the length of the molecular wire and negative differential resistance behaviors are observed in these systems. The mechanisms have been proposed for the length effect and negative differential resistance behavior.

scholarly journals Modeling of electrotransport properties of Li-intercalated graphene film

2021 ◽  
Vol 2140 (1) ◽  
pp. 012025
Author(s):  
D Sergeyev ◽  
A Duisenova ◽  
Zh Embergenov
Keyword(s):  
Negative Differential Resistance ◽  
Density Functional ◽  
Graphene Film ◽  
Differential Resistance ◽  
Maximum Amount ◽  
Differential Conductivity ◽  
Functional Theory ◽  
Quasiparticle Transport ◽  
Current Voltage ◽  
Current Voltage Characteristics

Abstract In this work, within the framework of density functional theory combined with the method of nonequilibrium Green’s functions the density of states, transmission spectrum, current-voltage characteristics, and differential conductivity of Li-intercalated graphene (LiC6) have been determined. It is shown that in the energy range of -1.3÷-1.05 eV the quasiparticle transport through the nanostructure is disable. The features of IV- and dI/dV-characteristics of LiC6 in the form of decreasing of resistance in the range of -0.4÷0.4 V were revealed, and in the interval of 0.4÷1.4 V formation of negative differential resistance area, related to scattering of quasiparticles. It is established, that LiC6 nanodevice has 12÷13 ballistic channels and has the maximum amount of conductance 12÷13G0 , where Go is the conductance quantum.

Density functional theory studies of Nb–benzene and Nb–borazine sandwich clusters and molecular wires

2012 ◽  
Vol 45 (2) ◽  
pp. 025102 ◽  
Author(s):  
Zhi Yang ◽  
Xuguang Liu ◽  
Shaoding Liu ◽  
Yongzhen Yang ◽  
Xiuyan Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Molecular Wires ◽  
Functional Theory

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.

Suppression by Pt of CO adsorption and dissociation and methane formation on Fe5C2(100) surfaces

2018 ◽  
Vol 20 (39) ◽  
pp. 25246-25255 ◽  
Author(s):  
Yurong He ◽  
Peng Zhao ◽  
Jinjia Liu ◽  
Wenping Guo ◽  
Yong Yang ◽  
...  
Keyword(s):  
Density Functional ◽  
Co Adsorption ◽  
Density Functional Theory Method ◽  
Methane Formation ◽  
Fischer Tropsch ◽  
Functional Theory ◽  
Spin Polarized ◽  
Synthesis Catalysts ◽  
Iron Based ◽  
Adsorption And Dissociation

To understand the chemical origin of platinum promotion effects on iron based Fischer–Tropsch synthesis catalysts, the effects of Pt on CO adsorption and dissociation as well as surface carbon hydrogenation on the Fe5C2(100) facet with different surface C* contents have been studied using the spin-polarized density functional theory method.

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