Tunable charge transport in single-molecule junctions via electrolytic gating.
We modulate the conductance of electrochemically inactive molecules in single-molecule junctions using an electrolytic gate to controllably tune the energy level alignment of the system. Molecular junctions that conduct through their highest occupied molecular orbital show a decrease in conductance when applying a positive electrochemical potential, and those that conduct though their lowest unoccupied molecular orbital show the opposite trend. We fit the experimentally measured conductance data as a function of gate voltage with a Lorentzian function and find the fitting parameters to be in quantitative agreement with self-energy corrected density functional theory calculations of transmission probability across single-molecule junctions. This work shows that electrochemical gating can directly modulate the alignment of the conducting orbital relative to the metal Fermi energy, thereby changing the junction transport properties.
Department of Applied Physics and Mathematics and ‡Department of Chemistry, Columbia University , New York, New York, United States.
Brian
B
Capozzi
Qishui
Q
Chen
Pierre
P
Darancet
Michele
M
Kotiuga
Marisa
M
Buzzeo
Jeffrey B
JB
Neaton
Colin
C
Nuckolls
Latha
L
Venkataraman