Contemplating Transport Characteristics by Augmenting the Length of Molecule

2013 ◽  
Vol 05 (03) ◽  
pp. 1350010 ◽  
Author(s):  
Milanpreet Kaur ◽  
Ravinder Singh Sawhney ◽  
Derick Engles
Keyword(s):  
Electron Tunneling ◽  
Tight Binding ◽  
Steady State Solution ◽  
The Self ◽  
Molecular Device ◽  
Hückel Theory ◽  
Single Electron Tunneling ◽  
Self Consistent ◽  
Semi Empirical ◽  
Non Equilibrium Green’S Function

In this paper, we contemplated the transport characteristics of a single molecular device junction by augmenting the length of the molecule in the scattering region. The molecules considered here belongs to class of alkanedithiols ( C n H 2n+2 S 2). Specifically, we used a tight binding semi-empirical model to compute the transport characteristics of butanedithiol, pentanedithiol, hexanedithiol and heptanedithiol connected to semi-infinite gold electrodes through thiol anchoring elements. The exploration of transport properties of considered alkanes was completed for different bias voltages within the sphere of Keldysh's Non Equilibrium Green's Function (NEGF) and Extended Hückel Theory (EHT), for studying the self-consistent steady-state solution, analyzing the out-of-equilibrium electron distribution, and the behavior of the self-consistent potential. We perceived that the current and conductance retrenches with aggravation with the increase in length of the molecule with exhibition of single electron tunneling. We observed that the coupling regime shifts from strong coupling to weak for higher order alkanedithiols and the transmission is function of evenness or oddness of the carbon atoms forming an alkane.

New Tight-Binding Method for Simulation of Defect Configurations, Creation and Diffusion Mechanisms in Solids: Application to Silicon

1998 ◽  
Vol 527 ◽  
Author(s):  
Zokirkhon M. Khakimov
Keyword(s):  
Tight Binding ◽  
The Self ◽  
Atomic Diffusion ◽  
Self Consistent ◽  
Tight Binding Method ◽  
Comparable Accuracy ◽  
Diffusion Mechanisms ◽  
New Generation ◽  
And Diffusion ◽  
Metastable Defect

ABSTRACTThis paper presents the self-consistent tight-binding method of new generation which, unlike other tight-binding methods, allows one to calculate structural energies of multiatomic systems (molecules, clusters, defects in solids) and their spectroscopic energies in the framework of the same computational scheme and with comparable accuracy. Reliability of the method is illustrated considering defect state problems in crystalline and amorphous silicon (electron-enhanced-atomic diffusion, metastable defect creation, defects with effective-negative correlation energies, etc.) and comparing obtained results with ab initio calculations and experimental data.

Tight-Binding Study of the {211} Σ=3 Grain Boundary in Cubic Silicon-Carbide

1994 ◽  
Vol 339 ◽  
Author(s):  
M. Kohyama ◽  
R. Yamamoto
Keyword(s):  
Grain Boundaries ◽  
Electronic Structures ◽  
Tight Binding ◽  
The Self ◽  
Localized States ◽  
General Definition ◽  
Self Consistent ◽  
Tight Binding Method ◽  
Definition Of ◽  
Cubic Silicon Carbide

ABSTRACTIn grain boundaries in compound semiconductors such as SiC, the interface stoichiometry and the wrong bonds between like atoms are of much importance. Firstly, a general definition of the interface stoichiometry in such grain boundaries has been discussed. Secondly, the atomic and electronic structures of the {211} Σ=3 boundary in SiC have been examined by using the self-consistent tight-binding method, based on the atomic models with bonding networks similar to those in the models of the same boundary in Si or Ge. The wrong bonds have significant effects through the large electrostatic repulsion and the generation of localized states as well as those in the {122} Σ=9 boundary in SiC. And the different bond lengths of the wrong bonds very much affect the local bond distortions at the interfaces, which determines the relative stability among the present models.

New Tight-Binding Method for Simulation of Defect Configurations, Creation and Diffusion Mechanisms in Solids: Application to Silicon

1998 ◽  
Vol 532 ◽  
Author(s):  
Zokirkhon M. Khakimov
Keyword(s):  
Tight Binding ◽  
The Self ◽  
Atomic Diffusion ◽  
Self Consistent ◽  
Tight Binding Method ◽  
Comparable Accuracy ◽  
Diffusion Mechanisms ◽  
New Generation ◽  
And Diffusion ◽  
Metastable Defect

ABSTRACTThis paper presents the self-consistent tight-binding method of new generation which, unlike other tight-binding methods, allows one to calculate structural energies of multiatomic systems (molecules, clusters, defects in solids) and their spectroscopic energies in the framework of the same computational scheme and with comparable accuracy. Reliability of the method is illustrated considering defect state problems in crystalline and amorphous silicon (electronenhanced- atomic diffusion, metastable defect creation, defects with effective-negative correlation energies, etc.) and comparing obtained results with ab initio calculations and experimental data.

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