Switching and oscillation of current along quinone based molecular device with graphene electrodes

The electronic transport properties of quinone based molecular devices with zigzag graphene nanoribbon electrodes are investigated by using non-equilibrium Green's function and density functional theory. Although the devices with lateral linking groups -CONH and -NH2 display different switching behavior, different lateral linking groups do not influence the presence of oscillated current. We discuss the switching effect, reversed current and oscillated current according to the transmission spectra and molecular projected self-consistent Hamiltonian. And the evolution of the frontier molecular orbital with the increase of bias is depicted to study effect of different linking group on the electron transmission. The results suggest that electron-withdrawing group -CONH is in favor of electron transmission and oscillated current originates from the change of molecule-electrodes coupling.