Thin Solid Films, Vol.518, No.2, 466-469, 2009
Highly conductive single molecular junctions by direct binding of pi-conjugated molecule to metal electrodes
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)=2e(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 pi-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 x 10(-3) G(0). It was suggested that the anchoring groups acted as resistive spacers between the molecule and metal. (C) 2009 Elsevier B.V. All rights reserved.
Keywords:Electrical transport;Single molecular junction;Fullerene;Mechanically controllable break junction;Scanning tunneling microscope