The Effects of π and σ Coupling on Electron Transport in a Molecular Assembly System

The purpose of this paper is to study the electronic transport through molecular assembly system (MAS) by presenting I‐V and G‐V characteristics analysis for different geometry structure. The model involves 1,4‐dithiolbenzene (DTB) (HSC6H4SH) molecules stacked in (1D) ordered structure. The MAS can contain up to six DTB molecules packed in the parallel geometrical arrangement connected between two electrodes. The relationship between the threshold voltage Vth, the metal‐molecule interaction strength σi and N the number of DTB molecular units which involves the π‐orbital interactions is investigated. The simulation results show that Vth changes significantly and depends on N. The system in the regime of stronger π‐interactions obtained with larger N reduces Vth. On the contrary, σi shows no effect on Vth. Moreover, in such molecular assembly system junctions, the connection between the molecule and the electrodes greatly affects the current‐voltage characteristics, particularly in the saturation region.