The electronic transport properties of molecular junctions based on four boron clusters, B32, B39, B42, and B45, that have tubular ground state structures were studied using first principles calculations and non-equilibrium Green's function simulations. Spin polarized calculations indicate that the charge transport properties are almost spin-independent at low bias voltages. In fact, only the junction based on B39 exhibits the spin polarization effect, while the other open-shell cluster (B45) shows no spin dependence due to its coupling with the electrodes. The calculated current-voltage characteristics show that the four types of molecular junctions have diverse functionalities, with the B32 and B39 junctions exhibiting current limiting features, while a clear negative differential resistance effect was found in the B42 and B45 junctions. These results suggest that molecular junctions based on boron clusters, which support rich geometrical and electronic properties, could serve as an important group of candidates for constructing functional molecular devices.
Wang et al. (Fri,) studied this question.