Electric Transport Properties of a Model Nanojunction “Graphene–Fullerene C60–Graphene”

Abstract

In the framework of the density functional theory and method of nonequilibrium Green functions (DFT [Formula: see text] NEGF), the electric transport properties of the model nanojunction “Graphene–Fullerene C[Formula: see text]–Graphene” were studied. The transmission spectra, the density of states, the current–voltage characteristic (CVC) and the differential conductivity of the nanojunction are determined. The appearance of a feature of the DOS nanotransition is revealed. This is due to the fact that the Lowest Unoccupied Molecular Orbital (LUMO) of C[Formula: see text] becomes closer to the Fermi level of metal substrates than its Highest Occupied Molecular Orbital (HOMO). It is shown that Coulomb stairs associated with the Coulomb blockade effect appear on the CVC of the nanotransition. The same changes are observed on the differential conductivity spectrum in the form of eight distinct peak structures arising with period [Formula: see text][Formula: see text]V. The comparison of the electric transport characteristics of single-fullerene nanodevices with various electrode materials (graphene, gold, platinum) are presented. It was found that the voltage period of Coulomb features [Formula: see text] in a nanodevice with graphene electrodes is less than in nanodevices with platinum and gold electrodes. It was revealed that the considered nanotransition has negative differential conductivity. The results obtained can be useful in calculating promising elements of single-electronics.