Electromechanical Characteristics by a Vertical Flip of C(70) Fullerene Prolate Spheroid in a Single-Electron Transistor: Hybrid Density Functional Methods

In this study, the B3LYP hybrid density functional theory was used to investigate the electromechanical characteristics of C(70) fullerene with and without point charges to model the effect of the surface of the gate electrode in a C(70) single-electron transistor (SET). To understand electron tunneling through C(70) fullerene species in a single-C(70) transistor, descriptors of geometrical atomic structures and frontier molecular orbitals were analyzed. The findings regarding the node planes of the lowest unoccupied molecular orbitals (LUMOs) of C(70) and both the highest occupied molecular orbitals (HOMOs) and the LUMO of the C(70) anion suggest that electron tunneling of pristine C(70) prolate spheroidal fullerene could be better in the major axis orientation when facing the gate electrode than in the major (longer) axis orientation when facing the Au source and drain electrodes. In addition, we explored the effect on the geometrical atomic structure of C(70) by a single-electron addition, in which the maximum change for the distance between two carbon sites of C(70) is 0.02 Å.