Highly conductive single molecular junctions by direct binding of π-conjugated molecule to metal electrodes

Abstract

We have investigated electrical conductance of the single C 60 and benzene molecules bridging between metal electrodes. The single C 60 and benzene molecular junctions were prepared in ultra high vacuum. The single molecular junctions showed the high conductance values (around 0.1–1 G 0: G 0 = 2 e 2/ h), which were comparable to that of the metal atomic contact. The highly conductive single molecular junctions could be prepared by direct binding of the π-conjugated organic molecule to the metal electrodes without the use of anchoring groups. For comparison, the single 1,4-benzenediamine molecular junction was investigated in solution. The benzene molecule was bound to the Au electrodes via amine (anchoring group) for the single 1,4-benzenediamine molecular junction. The conductance of the single 1,4-benzenediamine molecular junction was 8 × 10 − 3 G 0. It was suggested that the anchoring groups acted as resistive spacers between the molecule and metal.