Transition From Direct Tunneling to Field Emission in Metal-Molecule-Metal Junctions
J M. Beebe, BongSoo Kim, John William Gadzuk, C D. Frisbie, James G. Kushmerick
Current-voltage measurements of metal-molecule-metal tunnel junctions formed from p-conjugated thiols exhibit an inflection point on a plot of ln(I/V2) against 1/V, consistent with a transition in tunneling barrier shape from trapezoidal to triangular. The position of this inflection point was found to scale linearly with the offset in energy between the Au Fermi level and the highest occupied molecular orbital as determined by ultraviolet photoelectron spectroscopy. Asymmetric voltage drops at the two metal-molecule interfaces lead to a bias polarity dependence of the barrier transition.
, Kim, B.
, , J.
, Frisbie, C.
and Kushmerick, J.
Transition From Direct Tunneling to Field Emission in Metal-Molecule-Metal Junctions, Physical Review Letters
(Accessed September 21, 2023)