Electrochemical setup - a unique chance to simultaneously control orbital energies and vibrational properties of single-molecule junctions with unprecedented efficiency

Abstract

Impressive advances in nanoscience permit nowadays to manipulate single molecules and broadly control many of their properties. Still, tuning the molecular charge and vibrational properties of single molecules embedded in nanojunctions in broad ranges escaped so far to an efficient control. By combining theoretical results with recent experimental data, we show that, under electrochemical control, it is possible to continuously drive a redox molecule (viologen) between almost perfect oxidized and reduced states. This yields an unprecedentedly efficient control on both vibrational frequencies and the surface-enhanced Raman scattering (SERS) intensities. The broad tuning achieved under electrochemical control by varying the overpotential ("gate potential") within experimentally accessible ranges contrasts to the case of two-terminal setups that require high biases, which real nanojunctions cannot withstand. The present study aim at stimulating concurrent transport and SERS measurements in electrochemical setup. This may open a new avenue of research that is not accessible via two-terminal approaches for better understanding the transport at nanoscale.

References in corpus (13)

• Mechanically-Controlled Binary Conductance Switching of a Single-Molecule Junction
• Highly conductive molecular junctions based on direct binding of benzene to platinum electrodes
• Simultaneous measurements of electronic conduction and Raman response in molecular junctions
• Vibrational and electronic heating in nanoscale junctions
• Irreversibility and hysteresis in redox molecular conduction junctions
• Voltage tuning of vibrational mode energies in single-molecule junctions
• Influence of chopped laser light onto the electronic transport through atomic-sized contacts
• Modeling elastic and photoassisted transport in organic molecular wires: length dependence and current-voltage characteristics
• A quantum chemical study from a molecular perspective: ionization and electron attachment energies for species often used to fabricate single-molecule junctions
• Extending the Newns-Anderson model to allow nanotransport studies through molecules with floppy degrees of freedom
• (4,4')-Bipyridine in Vacuo and in Solvents: A Quantum Chemical Study of a Prototypical Floppy Molecule From a Molecular Transport Perspective
• Sources of negative differential resistance in electric nanotransport
• Quantifying the relative molecular orbital alignment for molecular junctions with similar chemical linkage to electrodes

Cited by in corpus (3)

• Why Asymmetric Molecular Coupling to Electrodes Cannot Be at Work in Real Molecular Rectifiers
• Counterintuitive issues in the charge transport through molecular junctions
• An important impact of the molecule-electrode couplings asymmetry on the efficiency of bias-driven redox processes in molecular junctions