Theory of the Rectifying Performance in Molecular Device: The Role of Anchoring Groups

2011 ◽  
Vol 181-182 ◽  
pp. 344-347 ◽  
Author(s):  
Cai Juan Xia ◽  
Han Chen Liu ◽  
Ying Tang Zhang
Keyword(s):  
Single Molecule ◽  
Electronic Transport ◽  
Density Functional ◽  
Electrical Response ◽  
Molecular Device ◽  
Functional Theory ◽  
Transmission Coefficients ◽  
External Bias ◽  
Anchoring Groups

The electronic transport of the single molecule via different anchoring groups is studied using density functional theory in conjunction with the nonequilibrium Green’s function. The results show that the electronic transport properties are strongly dependent on the anchoring groups. Asymmetric electrical response for opposite biases is observed resulting in significant rectification in current. The transmission coefficients and spatial distributions of molecular orbitals under various external biases voltage are analyzed, and it suggests that the asymmetry of the coupling between the molecule and the electrodes with external bias leads to rectifying performance.

Modulation of Low Bias Negative Differential Resistance in a Molecular Device by Adjusting Anchoring Groups

2014 ◽  
Vol 1070-1072 ◽  
pp. 479-482
Author(s):  
Li Hua Wang ◽  
Heng Fang Meng ◽  
Bing Jun Ding ◽  
Yong Guo
Keyword(s):  
Electronic Transport ◽  
Negative Differential Resistance ◽  
Density Functional ◽  
Function Method ◽  
Differential Resistance ◽  
Carbon Chain ◽  
Molecular Device ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Anchoring Groups

We investigate electronic transport properties of molecular device models constructed by a dipyrimidinyl–dimethyl molecule embedding in a carbon chain, which are then coupled to the gold electrodes through thiol or isocyanide group. Using the density functional theory combined with the nonequilibrium Green’s function method, negative differential resistance behaviors are observed in such molecular junctions. Most importantly, system with the isocyanide group can achieve a larger negative differential resistance at lower bias voltage (0.1V).

THEORETICAL STUDIES OF THE RECTIFYING PERFORMANCE IN DIBLOCK MOLECULAR JUNCTIONS: THE ROLE OF THE ANCHORING GROUPS

2012 ◽  
Vol 26 (11) ◽  
pp. 1250082 ◽  
Author(s):  
CAI-JUAN XIA ◽  
DE-SHENG LIU ◽  
DE-HUA ZHANG ◽  
HAN-CHEN LIU
Keyword(s):  
Transport Properties ◽  
Electronic Transport ◽  
Density Functional ◽  
Careful Consideration ◽  
Molecular Junctions ◽  
Electronic Transport Properties ◽  
Transmission Coefficients ◽  
Chemical Structures ◽  
Anchoring Groups

By applying nonequilibrium Green's function formalism combined with first-principles density functional theory, we investigate the effect of different anchoring groups on the rectifying behavior in diblock molecular junctions. The spatial distributions of molecular orbitals and the influence of transmission coefficients under various external voltage biases on the electronic transport through the molecular device are discussed in detail. The results show that the anchoring groups play a significant role on the electronic transport properties. The rectifying performance in molecular junctions can be manipulated, enhanced, or suppressed by a careful consideration of the effects of the anchoring group and such modifications become crucial in optimizing the electronic transport properties of chemical structures.

The Quantum Length Dependence of Conductance in Molecular Device: An Ab Initio Study

2010 ◽  
Vol 663-665 ◽  
pp. 519-522
Author(s):  
Cai Juan Xia ◽  
Han Chen Liu ◽  
Ying Tang Zhang
Keyword(s):  
Electronic Transport ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Molecular Device ◽  
Functional Theory ◽  
Length Dependence ◽  
Molecular Conductance ◽  
Homo Lumo ◽  
Molecular Compounds

By Applying Nonequilibrium Green’s Function Formalism Combined First-Principles Density Functional Theory, we Investigate the Electronic Transport Properties of Thiophene and Furan Molecules with Different Quantum Length. the Influence of HOMO-LUMO Gaps and the Spatial Distributions of Molecular Orbitals on the Electronic Transport through the Molecular Device Are Discussed in Detail. the Results Show that the Transport Behaviors Are Determined by the Distinct Electronic Structures of the Molecular Compounds. the Length Dependence of Molecular Conductance Exhibits its Diversity for Different Molecules.

An Ab Initio Study on Negative Differential Resistance in Pyrrole Trimer Molecular Device

2010 ◽  
Vol 152-153 ◽  
pp. 931-934
Author(s):  
Cai Juan Xia ◽  
Han Chen Liu ◽  
Qiu Ping Wang
Keyword(s):  
Electronic Transport ◽  
First Principles ◽  
Negative Differential Resistance ◽  
Density Functional ◽  
Differential Resistance ◽  
Resonance Peak ◽  
Molecular Device ◽  
Transmission Resonance ◽  
Functional Theory ◽  
Theoretical Results

The electronic transport properties of pyrrole trimer sandwiched between two electrodes are investigated by using nonequilibrium Green’s function formalism combined first-principles density functional theory. Theoretical results show that the system manifests negative differential resistance (NDR) behavior. A detailed analysis of the origin of negative differential resistance has been given by observing the shift in transmission resonance peak across the bias window with varying bias voltage.

EFFECT OF ASYMMETRIC LATERAL LINKING GROUPS ON THE ELECTRONIC TRANSPORT IN MOLECULAR DEVICE

2021 ◽  
Author(s):  
YAMIN WU ◽  
BIN LIAO ◽  
GUOLIANG WANG ◽  
BAOAN Bian
Keyword(s):  
Density Functional Theory ◽  
Molecular Orbital ◽  
Electronic Transport ◽  
Density Functional ◽  
Molecular Junctions ◽  
Frontier Molecular Orbital ◽  
Asymmetric Distribution ◽  
Molecular Device ◽  
Functional Theory ◽  
Lateral Linking

The effect of asymmetric lateral linking groups on the electronic transport is investigated in the biphenyl molecule-based device with gold electrodes with the framework of density functional theory and nonequilibrium Green’s function. The asymmetric lateral linking groups reduce the currents of molecular junctions, and result in the reverse rectifying behavior. The devices with asymmetric lateral linking groups –SH and –SCH3 have maximum rectifying ratios, while the asymmetric lateral linking group –SH and –NH2 cause minimum rectifying ratios. The calculated results suggest that the asymmetric lateral linking group induces the reduced coupling between molecule and right electrode, asymmetric distribution of frontier molecular orbital and asymmetric evolution of the molecular orbital eigenenergies, accounting for the rectifying behavior.

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.

THEORETICAL STUDY OF THE ELECTRON TRANSPORT THROUGH THE CYSTEINE AMINO ACID NANOMOLECULAR WIRE

2008 ◽  
Vol 07 (02n03) ◽  
pp. 95-102 ◽  
Author(s):  
M. D. GANJI ◽  
H. AGHAIE ◽  
M. R. GHOLAMI
Keyword(s):  
Electrical Transport ◽  
Density Functional ◽  
Differential Resistance ◽  
Self Assembled Monolayer ◽  
Functional Theory ◽  
Transmission Coefficients ◽  
External Bias ◽  
The Density Functional Theory ◽  
Au Nanowires ◽  
Cysteine Amino Acid

In this paper, we study the electrical transport and Negative Differential Resistance (NDR) in a single molecular conductor consisting of a cysteine sandwiched between two Au (111) electrodes via the Density Functional Theory-based Nonequilibrium Green's Function (DFT-NEGF) method. We show that (surprisingly, despite their apparent simplicity, these Au /cysteine/ Au nanowires are shown to be a convenient NDR device) the smallest two-terminal molecular wire can exhibit NDR behavior to date. Experiments with a conventional or novel self-assembled monolayer (SAM) are proposed to test these predictions. The projected density of states (PDOSs) and transmission coefficients T(E) under various external voltage biases are analyzed, and it suggests that the variation of the coupling between the molecule and the electrodes with external bias leads to NDR.

EFFECT OF TORSION ANGLE ON THE RECTIFYING PERFORMANCE IN THE DONOR-BRIDGE-ACCEPTOR SINGLE MOLECULAR DEVICE

2012 ◽  
Vol 11 (04) ◽  
pp. 735-743 ◽  
Author(s):  
CAI-JUAN XIA ◽  
YING-TANG ZHANG ◽  
DE-SHENG LIU
Keyword(s):  
Electronic Transport ◽  
First Principles ◽  
Torsion Angle ◽  
Density Functional ◽  
Coupling Effect ◽  
Molecular Devices ◽  
Molecular Device ◽  
Functional Theory ◽  
Homo Lumo ◽  
Theoretical Results

By applying nonequilibrium Green's function formalism combined with first-principles density functional theory, we investigate the effect of torsion angle on the rectifying performance in the donor-bridge-acceptor single molecular device. The influence of HOMO–LUMO gaps and the spatial distributions of molecular orbitals on the electronic transport through the molecular device are discussed in detail. The theoretical results show that the torsion angle plays an important role in the rectifying behavior of such devices. By changing the torsion angle, namely changing the magnitude of the intermolecular coupling effect, a different rectifying behavior can be observed in these systems. The results can provide fundamental guidelines for the design of functional molecular devices to a certain extent.

scholarly journals Adsorbate-driven cooling of carbene-based molecular junctions

2017 ◽  
Vol 8 ◽  
pp. 2060-2068 ◽  
Author(s):  
Giuseppe Foti ◽  
Héctor Vázquez
Keyword(s):  
Single Molecule ◽  
First Principles ◽  
Density Functional ◽  
Energy Exchange ◽  
Vibrational Modes ◽  
Functional Theory ◽  
Molecular Adsorbates ◽  
Heating And Cooling ◽  
Inelastic Tunneling

We study the role of an NH2 adsorbate on the current-induced heating and cooling of a neighboring carbene-based molecular circuit. We use first-principles methods of inelastic tunneling transport based on density functional theory and non-equilibrium Green’s functions to calculate the rates of emission and absorbtion of vibrations by tunneling electrons, the population of vibrational modes and the energy stored in them. We find that the charge rearrangement resulting from the adsorbate gates the carbene electronic structure and reduces the density of carbene states near the Fermi level as a function of bias. These effects result in the cooling of carbene modes at all voltages compared to the “clean” carbene-based junction. We also find that the direct influence of adsorbate states is significantly smaller and tends to heat adsorbate vibrations. Our results highlight the important role of molecular adsorbates not only on the electronic and elastic transport properties but also on the current-induced energy exchange and stability under bias of single-molecule circuits.

Electronic transport induced by doping on the electrodes in molecular devices

2020 ◽  
Vol 19 (08) ◽  
pp. 2050030
Author(s):  
Jingjuan Yang ◽  
Jinlei Wei ◽  
Bin Liao ◽  
Baoan Bian ◽  
Guoliang Wang ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electronic Transport ◽  
Density Functional ◽  
Local Density ◽  
Molecular Device ◽  
Local Density Of States ◽  
Functional Theory ◽  
Electronic Transport Properties ◽  
Non Equilibrium Green’S Function ◽  
Left Electrode

The electronic transport properties of molecular device based on photochromic diarylethene with carbon nanotube electrode are investigated by density functional theory and non-equilibrium Green’s function. The devices with open and closed configurations show a switching effect. It is found that doping of different amounts of nitrogen atoms on left electrodes results in different electronic transport properties. In addition, we discuss the observed oscillation of current in the devices induced by doping using transmission eigenstates and transmission spectra of the device. The local density of states of the device is calculated to analyze the observed rectifying behavior. The results suggest that doping of nitrogen atoms on the left electrode can be considered as a factor to modulate the electronic transport properties of molecular device.

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