We report on a theoretical study of the electronic transport properties of binuclear complexes of metals of the VIII group bridged by pyrazine. Metal-porphyrazine units have been combined in order to investigate symmetric and non-symmetric species with particular focus on their current rectification properties. Transmission functions and I-V characteristics of the various species have been computed using a Non-Equilibrium Green Function with a simplified treatment of the molecule-lead interaction. The results obtained show an overall moderate asymmetry in the current along the molecules, which is of the donors- acceptor type and follow the trend of the ionization potential of the metals in the binuclear system. The bias-dependent rectification ratio, which is significant in a limited voltage window, can be explained in terms of the alignment of the occupied orbitals of the metallic fragments that contribute to the HOMO and HOMO - 1 of the supermolecule. The possible improvement of the rectification performance of such a class of molecules has also been investigated exploiting suitable substitution by electron-withdrawing groups.
|Autori:||Vincenzo Barone;Ivo Cacelli;Alessandro Ferretti;Michele Visciarelli|
|Titolo:||Transport properties of binuclear metal complexes of the VIII group using a simplified NEGF-DFT approach|
|Anno del prodotto:||2013|
|Digital Object Identifier (DOI):||10.1039/c3cp50974e|
|Appare nelle tipologie:||1.1 Articolo in rivista|