Enhanced rectifying performance by asymmetrical gate voltage for BDC20 molecular devices
By applying the asymmetrical gate voltage on the 1,4-bis (fullero[c]pyrrolidin-1-yl) benzene BDC20 molecule, we investigate theoretically its electronic transport properties using the density functional theory and nonequilibrium Green's function formalism for a unimolecule device with metal electrodes. Interestingly, the rectifying characteristic with very high rectification ratio, 91.7 and 24.0, can be obtained when the gate voltage is asymmetrically applied on the BDC20 molecular device. The rectification direction can be tuned by the different gate voltage applying regions. The rectification behavior is understood in terms of the evolution of the transmission spectrum and projected density of states spectrum with applied bias combined with molecular projected self-consistent Hamiltonian states analyses. Our finding implies that to realize and greatly promote rectifying performance of the BDC20 molecule the variable gate voltage applying position might be a key issue.