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Molecular Tunnel Junctions Based On π-conjugated Oligoacene Thiols And Dithiols Between Ag, Au, And Pt Contacts: Effect Of Surface Linking Group And Metal Work Function.
B. Kim, S. Choi, X. Zhu, C. Frisbie
Published 2011 · Medicine, Chemistry
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The tunneling resistance and electronic structure of metal-molecule-metal junctions based on oligoacene (benzene, naphthalene, anthracene, and tetracene) thiol and dithiol molecules were measured and correlated using conducting probe atomic force microscopy (CP-AFM) in conjunction with ultraviolet photoelectron spectroscopy (UPS). Nanoscopic tunnel junctions (~10 nm(2)) were formed by contacting oligoacene self-assembled monolayers (SAMs) on flat Ag, Au, or Pt substrates with metalized AFM tips (Ag, Au, or Pt). The low bias (<0.2 V) junction resistance (R) increased exponentially with molecular length (s), i.e., R = R(0) exp(βs), where R(0) is the contact resistance and β is the tunneling attenuation factor. The R(0) values for oligoacene dithiols were 2 orders of magnitude less than those of oligoacene thiols. Likewise, the β value was 0.5 per ring (0.2 Å(-1)) for the dithiol series and 1.0 per ring (0.5 Å(-1)) for the monothiol series, demonstrating that β is not simply a characteristic of the molecular backbone but is strongly affected by the number of chemical (metal-S) contacts. R(0) decreased strongly as the contact work function (Φ) increased for both monothiol and dithiol junctions, whereas β was independent of Φ within error. This divergent behavior was explained in terms of the metal-S bond dipoles and the electronic structure of the junction; namely, β is independent of contact type because of weak Fermi level pinning (UPS revealed E(F) - E(HOMO) varied only weakly with Φ), but R(0) varies strongly with contact type because of the strong metal-S bond dipoles that are responsible for the Fermi level pinning. A previously published triple barrier model for molecular junctions was invoked to rationalize these results in which R(0) is determined by the contact barriers, which are proportional to the size of the interfacial bond dipoles, and β is determined by the bridge barrier, E(F) - E(HOMO). Current-voltage (I-V) characteristics obtained over a larger voltage range 0-1 V revealed a characteristic transition voltage V(trans) at which the current increased more sharply with voltage. V(trans) values were generally >0.5 V and were well correlated with the bridge barrier E(F) - E(HOMO). Overall, the combination of electronic structure determination by UPS with length- and work function-dependent transport measurements provides a remarkably comprehensive picture of tunneling transport in molecular junctions based on oligoacenes.
This paper references
Charge transfer and “band lineup” in molecular electronic devices: A chemical and numerical interpretation
Yongqiang Xue (2001)
Organic/metal interfaces in self-assembled monolayers of conjugated thiols: A first-principles benchmark study
G. Heimel (2006)
Interface Dipoles Arising from Self-Assembled Monolayers on Gold: UV−Photoemission Studies of Alkanethiols and Partially Fluorinated Alkanethiols
Dana M. Alloway (2003)
The structure, energetics, and nature of the chemical bonding of phenylthiol adsorbed on the Au(111) surface: implications for density-functional calculations of molecular-electronic conduction.
A. Bilić (2005)
Renormalization of molecular electronic levels at metal-molecule interfaces.
J. Neaton (2006)
Self-assembled monolayers from biphenyldithiol derivatives: optimization of the deprotection procedure and effect of the molecular conformation.
A. Shaporenko (2006)
Progress with molecular electronic junctions: meeting experimental challenges in design and fabrication.
R. McCreery (2009)
J. Kushmerick (2005)
Formation and Structure of Self-Assembled Monolayers.
A. Ulman (1996)
Length-dependent transport in molecular junctions based on SAMs of alkanethiols and alkanedithiols: effect of metal work function and applied bias on tunneling efficiency and contact resistance.
Vincent B. Engelkes (2004)
Quantifying transition voltage spectroscopy of molecular junctions: Ab initio calculations
J. Chen (2010)
Fermi level alignment in self-assembled molecular layers: the effect of coupling chemistry.
C. Zangmeister (2006)
Electrical conductance of oligothiophene molecular wires.
R. Yamada (2008)
Transition voltage spectroscopy of porphyrin molecular wires.
N. Bennett (2010)
Observation of molecular orbital gating
Hyunwook Song (2009)
Energy-level alignment and work function shifts for thiol-bound monolayers of conjugated molecules self-assembled on Ag, Cu, Au, and Pt
C. Zangmeister (2007)
Electrical Resistance of Long Conjugated Molecular Wires
Seong Ho Choi (2008)
Contact chemistry and single-molecule conductance: a comparison of phosphines, methyl sulfides, and amines.
Y. S. Park (2007)
Effects of Hindered Internal Rotation on Packing and Conductance of Self-Assembled Monolayers
A. A. Dameron (2004)
Nanoscale switch elements from self-assembled monolayers on silver
Jeremy M. Beebe (2007)
Electronic structure of thiol-bonded self-assembled monolayers : Impact of coverage
Lorenz Romaner (2008)
Correlation between HOMO alignment and contact resistance in molecular junctions: aromatic thiols versus aromatic isocyanides.
B. Kim (2006)
Self-Assembly of Alkanethiol Molecules onto Platinum and Platinum Oxide Surfaces
Z. Li (2003)
Thermoelectricity in Molecular Junctions
P. Reddy (2007)
Measuring relative barrier heights in molecular electronic junctions with transition voltage spectroscopy.
Jeremy M. Beebe (2008)
Interpretation of transition voltage spectroscopy.
E. H. Huisman (2009)
Oscillation of conductance in molecular junctions of carbon ladder compounds.
T. Tada (2004)
Molecular Transport Junctions: Clearing Mists
S. Lindsay (2007)
Frustrated rotations in single-molecule junctions.
Y. S. Park (2009)
Superior contact for single-molecule conductance: electronic coupling of thiolate and isothiocyanate on Pt, Pd, and Au.
Chih-Hung Ko (2010)
Toward control of the metal-organic interfacial electronic structure in molecular electronics: a first-principles study on self-assembled monolayers of pi-conjugated molecules on noble metals.
G. Heimel (2007)
Single‐ and Double‐Deformation Faults in Face‐Centered Cubic Crystals
B. Warren (1963)
Influence of metal-molecule contacts on decay coefficients and specific contact resistances in molecular junctions
G. Wang (2007)
Length Dependence of Electron Conduction for Oligo(1,4-phenylene ethynylene)s: A Conductive Probe-Atomic Force Microscopy Investigation
K. Liu (2008)
Effects of Metal−Molecule Contact and Molecular Structure on Molecular Electronic Conduction in Nonresonant Tunneling Regime: Alkyl versus Conjugated Molecules
G. Wang (2008)
Conductance of single 1,4-disubstituted benzene molecules anchored to Pt electrodes
M. Kiguchi (2007)
Theoretical calculations of electron transport in molecular junctions: Inflection behavior in Fowler-Nordheim plot and its origin
M. Araidai (2010)
Charge transport through image charged stabilized states in a single molecule single electron transistor device
P. Hedegård (2005)
Identifying the length dependence of orbital alignment and contact coupling in molecular heterojunctions.
J. Malen (2009)
Polarization-induced renormalization of molecular levels at metallic and semiconducting surfaces
J. M. García-Lastra (2009)
Conductance and geometry of pyridine-linked single-molecule junctions.
M. Kamenetska (2010)
The nature of transport variations in molecular heterojunction electronics.
J. Malen (2009)
Revealing molecular orbital gating by transition-voltage spectroscopy
Ioan Bâldea (2010)
Strong polarization-induced reduction of addition energies in single-molecule nanojunctions.
K. Kaasbjerg (2008)
Transition from direct tunneling to field emission in metal-molecule-metal junctions.
Jeremy M. Beebe (2006)
Oxidation potentials correlate with conductivities of aromatic molecular wires.
J. Quinn (2007)
Conductance of Molecular Wires: Influence of Molecule−Electrode Binding
S. Yaliraki (1999)
Odd-even effects in self-assembled monolayers of omega-(biphenyl-4-yl)alkanethiols: a first-principles study.
G. Heimel (2008)
Single-molecule junction conductance through diaminoacenes.
J. Quinn (2007)
Molecule-induced interface states dominate charge transport in Si-alkyl-metal junctions.
L. Yu (2008)
Single-electron transistor of a single organic molecule with access to several redox states
S. Kubatkin (2003)
Quantized conductance atomic switch
K. Terabe (2005)
Contact resistance in metal-molecule-metal junctions based on aliphatic SAMs: effects of surface linker and metal work function.
Jeremy M. Beebe (2002)
Valence electron orbitals of an oligo(p-phenylene-ethynylene)thiol on gold.
C. Zangmeister (2004)
Enhancement of field emission transport by molecular tilt configuration in metal-molecule-metal junctions.
Gunuk Wang (2009)
Comparison of Electronic Transport Measurements on Organic Molecules
Adi Salomon (2003)
Renormalization of molecular quasiparticle levels at metal-molecule interfaces: trends across binding regimes.
K. Thygesen (2009)
Controlling charge-carrier type in nanoscale junctions with linker chemistry.
C. Zangmeister (2008)
Interface energetics and level alignment at covalent metal-molecule junctions: pi-conjugated thiols on gold.
G. Heimel (2006)
Fermi Level Alignment and Electronic Levels in “Molecular Wire” Self-Assembled Monolayers on Au
C. Zangmeister (2004)
Temperature Dependent Barrier Crossover Regime in Tunneling Single Molecular Devices Based on the Matrix of Isolated Molecules
Andrei V. Pakoulev (2009)
From tunneling to hopping: a comprehensive investigation of charge transport mechanism in molecular junctions based on oligo(p-phenylene ethynylene)s.
Q. Lu (2009)
Analysis of the causes of variance in resistance measurements on metal-molecule-metal junctions formed by conducting-probe atomic force microscopy.
Vincent B. Engelkes (2005)
End group effect on electrical transport through individual molecules: A microscopic study
Yongqiang Xue (2004)
Electron transmission through molecules and molecular interfaces.
A. Nitzan (2001)
Measurement of single-molecule conductance.
F. Chen (2007)
Molecular junctions based on aromatic coupling.
S. Wu (2008)
Controlling Schottky energy barriers in organic electronic devices using self-assembled monolayers.
This paper is referenced by
Molecular Bending at the Nanoscale Evidenced by Tip-Enhanced Raman Spectroscopy in Tunneling Mode on Thiol Self-Assembled Monolayers
Chiara Toccafondi (2016)
Scaling Properties and Related Issues in the Charge Transport through Molecular Junctions
Ioan Bâldea (2017)
Fermi Level Pinning and Orbital Polarization Effects in Molecular Junctions: The Role of Metal Induced Gap States
C. Dyck (2014)
Effect of Electron Irradiation on Electric Transport Properties of Aromatic Self-Assembled Monolayers
Can Yildirim (2017)
Study of some physical properties of ultrasonically spray deposited silver doped lead sulphide thin films
Emrah Sarica (2017)
Electrical conductance of single-molecular junctions formed with palladium electrodes
Taekyeong Kim (2015)
Protocol for disentangling the thermally activated contribution to the tunneling-assisted charge transport. Analytical results and experimental relevance.
Ioan Bâldea (2017)
Light‐Stimulated Charge Transport in Bilayer Molecular Junctions for Photodetection
Shailendra K Saxena (2019)
Control of Rectification in Molecular Junctions: Contact Effects and Molecular Signature.
Quyen van Nguyen (2017)
Controlling and Observing Sharp-Valleyed Quantum Interference Effect in Single Molecular Junctions.
B. Huang (2018)
Single Nucleobase Identification Using Biophysical Signatures from Nanoelectronic Quantum Tunneling.
Lee Erik Korshoj (2017)
Why one can expect large rectification in molecular junctions based on alkane monothiols and why rectification is so modest† †Electronic supplementary information (ESI) available: Experimental and theoretical details, supplementary figures. See DOI: 10.1039/c8sc00938d
Zuoti Xie (2018)
Electronic Communication as a Transferable Property of Molecular Bridges?
C. Herrmann (2019)
Single molecule conductance of carboxylic acids contacting Ag and Cu electrodes
Zheng-Lian Peng (2012)
Charge Transfer Rates at a Bio−Inorganic Interface
Wenming Sun (2014)
Electron Transport and Redox Reactions in Solid-State Molecular Electronic Devices
Richard L McCreery (2015)
sition from an ohmic to a non-ohmic interface in supramolecular tunneling junctions with Ga 2 O 3 / EGaIn top electrodes †
K. Wimbush (2014)
An Artificial Optoelectronic Synapse Based on a Photoelectric Memcapacitor
L. Zhao (2020)
Transmission mechanism and quantum interference in fused thienoacenes coupling to Au electrodes through the thiophene rings.
Y. Li (2019)
The Origin of the Odd-Even Effect in the Tunneling Rates across EGaIn Junctions with Self-Assembled Monolayers (SAMs) of n-Alkanethiolates.
L. Jiang (2015)
Carbon Electrodes in Molecular Electronics
A. Bergren (2015)
Probing charge transfer dynamics in self-assembled monolayers by core hole clock approach
M. Zharnikov (2015)
Polymeric amphiphilic nanoparticles via intramolecular chain collapse using 1-functionalized vinylbenzocyclobutenes
W. Storms (2015)
Cross-plane transport in a single-molecule two-dimensional van der Waals heterojunction
Shiqiang Zhao (2020)
Valence Band Dependent Charge Transport in Bulk Molecular Electronic Devices Incorporating Highly Conjugated Multi-[(Porphinato)Metal] Oligomers.
R. C. Bruce (2016)
Effect of the heteroatom-separation on the electron transport behavior of heteroacene-junctions
Liuyang Zhang (2019)
Quantum interference enhanced chemical responsivity in single-molecule dithienoborepin junctions.
M. Baghernejad (2019)
Paving the way to single-molecule chemistry through molecular electronics.
Masateru Taniguchi (2019)
Is there a specific correlation between conductance and molecular aromaticity in single-molecule junctions?
G. Zhang (2017)
Impact of Electrode Density of States on Transport through Pyridine-Linked Single Molecule Junctions.
Olgun Adak (2015)
HOMO-LUMO coupling: the fourth rule for highly effective molecular rectifiers.
Aaron Zhenghui Thong (2017)
A surprising way to control the charge transport in molecular electronics: the subtle impact of the coverage of self-assembled monolayers of floppy molecules adsorbed on metallic electrodes.
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