Transport in fullerene device coupled to Cu, Ag and Au electrodes

To inquire the effects of different geometric electrodes on current characteristics of C24 fullerene molecular junction

Two different types of geometric electrode configurations were utilized to form C₂₄ fullerene based molecular junction. The C₂₄ molecule was intercalated in-between gold electrodes with two different shapes viz. knife edge and flat edge and the resultant molecular junctions (MJs) were simulated using nonequilibrium Green's function combined with semiempirical extended Huckel theory (EHT). Different transport parameters, namely projected device density of states, current-voltage curve, differential conductance curve, molecular orbitals, and transmission spectra were investigated at discrete bias voltages to gain insight about the various transport phenomena occurring in these molecular junctions. The results show that when the C₂₄ fullerene is placed in between the flat-edged electrodes, current and conductance are higher in magnitude in comparison to the knife-edged configuration. These deductions give us a new perspective to design advanced molecular devices for electronics applications in the future.

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

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. Graphical abstract Electrical characteristics of Endohedral fullerene junctions.

The DFT-NEGF scrutiny of doped fullerene junctions

Using the smallest non-classical fullerene, we investigate the impact of doping at the molecule-electrode interface on the electron transport of molecular junctions. This is accomplished by employing the density functional theory combined with the non-equilibrium Green's function. We contemplate different electronic parameters, namely, density of states, transmission coefficient, energy levels, molecular orbitals, conduction gaps, electron density, and their charge transfer. The relevance of these physical parameters is obtained to calculate their electrical parameters, current, and conductance, computed from Landauer-Büttiker formalism. The molecule-electrode coupling is influenced by the nature of doping atoms and affects the junction devices in a unique course. A particular aftermath is noticed in Au-C₁₈O₂-Au device with highest ballistic transport despite the electro-negative nature of oxygen atoms. Moreover, an interesting feature is observed in Au-C₁₈Be₂-Au device with double-barrier transmission resonance and corresponding oscillating conductance. Graphical abstract The doped C₂₀ fullerene in molecular and device mode.