Electrochemical Single-Molecule Transistors with Optimized Gate Coupling.
Electrochemical gating at the single molecule level of viologen molecular bridges in ionic liquids is examined. Contrary to previous data recorded in aqueous electrolytes, a clear and sharp peak in the single molecule conductance versus electrochemical potential data is obtained in ionic liquids. These data are rationalized in terms of a two-step electrochemical model for charge transport across the redox bridge. In this model the gate coupling in the ionic liquid is found to be fully effective with a modeled gate coupling parameter, ξ, of unity. This compares to a much lower gate coupling parameter of 0.2 for the equivalent aqueous gating system. This study shows that ionic liquids are far more effective media for gating the conductance of single molecules than either solid-state three-terminal platforms created using nanolithography, or aqueous media.
Departamento de Química Física, Facultad de Ciencias, Universidad de Zaragoza , 50009 Zaragoza, Spain.
Henrry M
HM
Osorio
Department of Chemistry, University of Liverpool , Crown Street, Liverpool, L69 7ZD, United Kingdom.
Samantha
S
Catarelli
Departamento de Química Física, Facultad de Ciencias, Universidad de Zaragoza , 50009 Zaragoza, Spain.|Instituto de Nanociencia de Aragón (INA) and Laboratorio de microscopias avanzadas (LMA), edificio i+d Campus Rio Ebro, Universidad de Zaragoza , C/Mariano Esquillor, s/n, 50018 Zaragoza, Spain.
Pilar
P
Cea
School of Chemistry and Biochemistry, University of Western Australia , 35 Stirling Highway, Crawley 6009, Australia.
Josef B G
JB
Gluyas
Department of Chemistry, University of Reading , Whiteknights, Reading, RG6 6AD, U.K.
František
F
Hartl
Department of Chemistry, University of Liverpool , Crown Street, Liverpool, L69 7ZD, United Kingdom.
Simon J
SJ
Higgins
Department of Chemistry, University of Liverpool , Crown Street, Liverpool, L69 7ZD, United Kingdom.
Edmund
E
Leary
School of Chemistry and Biochemistry, University of Western Australia , 35 Stirling Highway, Crawley 6009, Australia.
Paul J
PJ
Low
Departamento de Química Física, Facultad de Ciencias, Universidad de Zaragoza , 50009 Zaragoza, Spain.|Instituto de Ciencias de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC , 50009 Zaragoza, Spain.
Santiago
S
Martín
Department of Chemistry, University of Liverpool , Crown Street, Liverpool, L69 7ZD, United Kingdom.
Richard J
RJ
Nichols
Department of Chemistry, University of Reading , Whiteknights, Reading, RG6 6AD, U.K.
Joanne
J
Tory
Department of Chemistry and NanoDTU, Technical University of Denmark , DK2800 Kgs. Lyngby, Denmark.
Jens
J
Ulstrup
Department of Chemistry, University of Liverpool , Crown Street, Liverpool, L69 7ZD, United Kingdom.
Andrea
A
Vezzoli
Department of Chemistry, University of Liverpool , Crown Street, Liverpool, L69 7ZD, United Kingdom.
David C
DC
Milan
Department of Chemistry, University of Reading , Whiteknights, Reading, RG6 6AD, U.K.
Qiang
Q
Zeng