Ab initio scrutiny of endohedral C₂₀ fullerenes implanted in between gold electrodes

Abstract

Using the smallest non-classical fullerene, we investigate the impact of endohedral fullerene molecules on the quantum transport through molecular junctions, and then compared this with the pure C₂₀-based molecular junction. By employing the density functional theory combined with the non-equilibrium Green’s function, we contemplated different electronic parameters, namely, density of states, transmission coefficient, energy levels, molecular orbitals, conduction gaps, electron density and their charge transfer. A knowledge of these physical parameters is necessary in order to calculate current and conductance computed using Landauer-Büttiker formalism. The molecule-electrode coupling influenced by endohedral molecules affects junction devices in a unique manner. We observe that the highest quantum transport is possible in an Au–N@C₂₀–Au and Au–O@C₂₀–Au junction device, and is even higher than that of the intrinsic C₂₀ fullerene junction. Another notable observation is that the F@C₂₀ molecule exhibits the least conducting nature, being even lower than that of the endohedral molecule formed by inserting the noble element, neon.