Abstract

The electronic properties of an organic molecule under external electric field are investigated based on a single band tight-binding model Hamiltonian and the Green’s function approach with the Landauer–Büttiker formalism. These properties are studied for a chain of benzene rings (oligophenylene). A self-consistent calculation is adopted to analyze the external electric field effects on the electronic properties of system. It is shown that variation in electron density and HOMO–LUMO gap of the junction are direction depended on the external electric field strength. Our results show that in the presence of external electric field the transmission, current and tunnel magnetoresistance (TMR) decrease, the negative differential resistance occurs.