High-conductance states of single benzenedithiol molecules

Conductance of single 1,4-benzenedithiol (BDT) molecules is investigated in a wide range (0–0.3)G0, exploiting mechanically controllable break junction technique. The authors observed a series of clear conductance steps both in low- (∼0.01G0) and high-conductance (∼0.1G0) regimes and corresponding two sets of peak structures in the conductance histograms. The two distinct conductance states are attributable to different Au–S bonding configurations of Au∕BDT∕Au junctions. The high-bias measurements reveal that the high-conductance state of single BDT molecules is stable up to 1.6V and prospective for molecular device applications.