Switching function of the diphenylacetylene molecule between carbon nanotubes & carbon chain: A DFT study

Abstract

Using first-principles density functional theory and nonequilibrium Green’s function formalism, we investigate theoretically how the twist of torsional angle effect on the electronic transport properties of the diphenylacetylene (DPA) molecule bridged between a (5,5) capped carbon nanotubes (CCNTs) and linear carbon atomic chains. The tunneling current through the (5,5) capped CNT-DPA-linear carbon atomic chain system was found larger current when the torsional angle is 0° (coplanar conformation). BY increasing the torsional angle equal to 90° (perpendicular conformation), between two benzene rings, the current is strongly suppressed. These results suggest that the (5,5) capped CNT-DPA-linear carbon atomic chain system is a potential candidate for molecular switches. The physical origin of the switching behavior of the (5,5) capped CNT-DPA-linear carbon atomic chain system is systematically studied by analyses of transmission spectrum, energy gaps, the spatial distribution of frontier molecular orbital and current–voltage characteristics of the systems.