Electron transport phenomenon simulation through the carborane nano-molecular wire

• Published in: Physica. E, Low-dimensional systems & nanostructures Vol. 40; no. 9; pp. 2965 - 2972
• Main Authors: Aghaie, H., Gholami, M.R., Monajjemi, M., Ganji, M.D.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2008; Elsevier
• Subjects: Carboranes; Condensed matter: electronic structure, electrical, magnetic, and optical properties; DFT; Electron transport; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Molecular electronics; Non-Equilibrium Green's function; Physics; Carboranes; Molecular electronics; DFT; 73.40.Gk; 85.65.+h; Non-Equilibrium Green's function; 31.15.Ar; Electron transport; Molecular wires; Strong coupling; Electronic density of states; Molecular orbital method; Electron mobility; Density functional method; Nanowires; Green's function methods
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2008.02.014

The electron transport characteristics of a 1,10-dimethylene-1,10-dicarba-closo-decaborane (10-vertex carborane) single molecular conductor is investigated via the density functional-based non-equilibrium Green's function (DFT-NEGF) method. We consider three configurations for the molecular wire sandwiched between two Au(1 0 0) electrodes: the hollow site, top site and bridge site positions. Our results show that the energetically favorable hollow site configuration has a higher current intensity than the other configurations. The projection of the density of states (PDOS) and the transmission coefficients T( E) of the two-probe system at zero bias are analyzed, and it suggests that the variation of the coupling between the molecule and the electrodes with external bias leads to the higher conductance for the hollow configuration. Furthermore, the transmission coefficients of the hollow system at various external voltage biases are also investigated and it shows that the broadening of the transmission coefficient spectrum with increasing of the external voltage bias indicates a strong coupling between the molecular orbitals in the carborane and the incident states from the electrodes, and thus the current increases with increases of the bias voltage.