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.

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.

scholarly journals Effect of vacancy defects on the electronic transport properties of an Ag–ZnO–Pt sandwich structure

2021 ◽  
Vol 20 (2) ◽  
pp. 798-804
Author(s):  
G. R. Berdiyorov ◽  
F. Boltayev ◽  
G. Eshonqulov ◽  
H. Hamoudi
Keyword(s):  
Transport Properties ◽  
Electronic Transport ◽  
Density Functional ◽  
Practical Importance ◽  
Functional Formalism ◽  
Vacancy Defects ◽  
Electronic Transport Properties ◽  
Charge Localization ◽  
Metal Insulator Metal ◽  
Current Rectification

AbstractThe effect of zinc and oxygen vacancy defects on the electronic transport properties of Ag(100)–ZnO(100)–Pt(100) sandwich structures is studied using density functional theory in combination with the nonequilibrium Green’s functional formalism. Defect-free systems show clear current rectification due to voltage dependent charge localization in the system as revealed in our transmission eigenstates analysis. Regardless of the location, oxygen vacancies result in enhanced current in the system, whereas Zn vacancy defects reduce the charge transport across the junction. The current rectification becomes less pronounced in the presence of both types of vacancy defects. Our findings can be of practical importance for developing metal-insulator-metal diodes.

scholarly journals Effect of chemical modification on electronic transport properties of carbyne

2021 ◽  
Author(s):  
G. R. Berdiyorov ◽  
U. Khalilov ◽  
H. Hamoudi ◽  
Erik C. Neyts
Keyword(s):  
Transport Properties ◽  
Electronic Transport ◽  
Density Functional ◽  
Structural Changes ◽  
Carbon Chain ◽  
Functional Formalism ◽  
Functional Theory ◽  
Carbon Allotrope ◽  
Electronic Transport Properties ◽  
Interface Structures

AbstractUsing density functional theory in combination with the Green’s functional formalism, we study the effect of surface functionalization on the electronic transport properties of 1D carbon allotrope—carbyne. We found that both hydrogenation and fluorination result in structural changes and semiconducting to metallic transition. Consequently, the current in the functionalization systems increases significantly due to strong delocalization of electronic states along the carbon chain. We also study the electronic transport in partially hydrogenated carbyne and interface structures consisting of pristine and functionalized carbyne. In the latter case, current rectification is obtained in the system with rectification ratio up to 50%. These findings can be useful for developing carbyne-based structures with tunable electronic transport properties.

First-principles study of electronic transport properties of graphene nanoribbons with pentagon-heptagon (5-7) line defects

2015 ◽  
Vol 1727 ◽  
Author(s):  
Yasutaka Nishida ◽  
Takashi Yoshida ◽  
Fumihiko Aiga ◽  
Yuichi Yamazaki ◽  
Hisao Miyazaki ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electronic Transport ◽  
First Principles ◽  
Density Functional ◽  
Graphene Nanoribbons ◽  
Edge State ◽  
Line Defect ◽  
Electronic Transport Properties ◽  
Current Voltage ◽  
Line Defects

ABSTRACTIn this study, we investigated the influence of line defects consisting of pentagon-heptagon (5-7) pairs on the electronic transport properties of zigzag-edged and armchair-edged graphene nanoribbons (GNRs). Using the first-principles density functional theory, we study their electronic properties. To investigate their current-voltage (I-V) characteristics at low bias voltage (∼ 1 meV), we use the nonequilibrium Green’s function method. As a result, we found that the conductance of the GNRs having a connected line defect between source and drain shows better performance than that of the ideal zigzag-edged GNRs (ZGNRs). A detailed investigation of the transmission spectra and the wave function around the Fermi level reveals that the line defects arranged along the transport direction work similar to an edge state of the ZGNRs and can be an additional conduction channel. Our results suggest that such a line defect can be effective for low-resistance GNR interconnects.

Ab-initio calculations on the structural and electronic transport properties of five-atom GaN clusters

2019 ◽  
Vol 33 (29) ◽  
pp. 1950347 ◽  
Author(s):  
Xiao-Chong Liang ◽  
Xiao-Jiang Long ◽  
Lin Zhang ◽  
Jun Zhu
Keyword(s):  
Transport Properties ◽  
Electronic Transport ◽  
Density Functional ◽  
Differential Resistance ◽  
Pso Algorithm ◽  
Binding Energies ◽  
Functional Theory ◽  
Swarm Optimization ◽  
Electronic Transport Properties ◽  
Stable Structures

The structural and electronic transport properties of [Formula: see text] clusters are studied based on density functional theory (DFT). Their most stable structures are proved to be planar by the particle swarm optimization (PSO) algorithm, and have decreasing binding energies with the increasing number of Ga atom in clusters. The electronic transport properties of these clusters connected with two Al(1 0 0) electrodes are calculated by combining nonequilibrium Green’s-function (NEGF) with DFT. Most of them have an equilibrium conductance of above [Formula: see text], except for [Formula: see text]. Negative differential resistance (NDR) phenomenon of different level is observed in their I–V curves in bias ranges of from [Formula: see text] to [Formula: see text] V and from 0.7 to 1.1 V.

scholarly journals Length-Dependent Electronic Transport Properties of the ZnO Nanorod

Micromachines ◽  
2018 ◽  
Vol 10 (1) ◽  
pp. 26
Author(s):  
Baorui Huang ◽  
Fuchun Zhang ◽  
Yanning Yang ◽  
Zhiyong Zhang
Keyword(s):  
Transport Properties ◽  
Bias Voltage ◽  
Electronic Transport ◽  
Density Functional ◽  
Interface State ◽  
Zno Nanorod ◽  
Functional Theory ◽  
Electronic Transport Properties ◽  
Integrated Devices ◽  
Potential Applications

The two-probe device of nanorod-coupled gold electrodes is constructed based on the triangular zinc oxide (ZnO) nanorod. The length-dependent electronic transport properties of the ZnO nanorod was studied by density functional theory (DFT) with the non-equilibrium Green’s function (NEGF). Our results show that the current of devices decreases with increasing length of the ZnO nanorod at the same bias voltage. Metal-like behavior for the short nanorod was observed under small bias voltage due to the interface state between gold and the ZnO nanorod. However, the influence of the interface on the device was negligible under the condition that the length of the ZnO nanorod increases. Moreover, the rectification behavior was observed for the longer ZnO nanorod, which was analyzed from the transmission spectra and molecular-projected self-consistent Hamiltonian (MPSH) states. Our results indicate that the ZnO nanorod would have potential applications in electronic-integrated devices.

Electronic Transport Properties of SiC Nanotube with Antisite Defect

2011 ◽  
Vol 110-116 ◽  
pp. 5495-5499
Author(s):  
Jiu Xu Song ◽  
Hong Xia Liu
Keyword(s):  
Transport Properties ◽  
Electronic Transport ◽  
Density Functional ◽  
Wide Band ◽  
Antisite Defect ◽  
Wide Band Gap ◽  
Functional Theory ◽  
Electronic Transport Properties ◽  
Current Voltage ◽  
Sic Nanotube

The electronic transport properties of an (8, 0) SiC nanotube (SiCNT) with antisite defect are investigated with the method combined non-equilibrium Green’s function with density functional theory, in which the defect is formed with a carbon atom being substituted by a silicon atom. In transmission spectrum of the nanotube, a transmission valley about 1.68 eV near the Fermi energy is discovered, which indicates that the nanotube is a wide band-gap semiconductor. In its current-voltage characteristic, turn-on voltages of ±1.0 V are found under positive and negative bias. This originates from more orbital participating in its electronic transport properties caused by the bias. These results are meaningful to investigations on working mechanisms of SiCNT electronic devices.

Sign in / Sign up

Export Citation Format

Share Document