Electron transport study of two-terminal molecular electronic devices using ab initio methods

Abstract

An ab initio method based on density functional theory (DFT) combined with non-equilibrium Greena??s function (NEGF) is developed to study electron transport characteristics of two-terminal molecular electronic devices. The DFT-NEGF method has been implemented with FORTRAN 90 and the code has run on a supercomputer IBM P690. With DFT-NEGF method, electron transport properties of benzene based molecular electronic devices have been studied. The effects of electrode materials and terminal groups on the electron transport have been investigated. Preliminary simulation results show that benzene molecule shows non-linear conductive characteristics when coupling to metallic electrodes. Changing electrode materials will affect the amplitude of electron transport and terminal group plays important roles not only in chemisorbs between molecule and electrodes but also in electron transport through the metal-molecule-metal junctions. Developed method can be used to study the electron transport of any single molecule with two electrodes and can be easily updated to simulate the electronic properties of three-terminal molecular devices such as molecular transistors.