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Electrochemically controlled conductance switching in a single molecule: quinone-modified oligo(phenylene vinylene)
Stanislav Tsoi1, Igor Griva, Scott A Trammell
1Center for Bio-Molecular Science and Engineering, Naval Research Laboratory, Washington, DC 20375, USA.
ACS Nano
|February 12, 2009
Summary
Single quinone-oligo(phenylene vinylene) molecules exhibit reversible conductance switching. Applying electrochemical potential alters conductivity states by over 40x, paving the way for molecular electronics.
Area of Science:
- Molecular electronics
- Supramolecular chemistry
- Electrochemistry
Background:
- Conductance switching in single molecules is crucial for developing advanced electronic devices.
- Oligo(phenylene vinylene) derivatives offer tunable electronic properties.
- Understanding the molecular mechanisms of switching is essential for device optimization.
Purpose of the Study:
- To demonstrate reversible conductance switching in single quinone-oligo(phenylene vinylene) (Q-OPV) molecules.
- To investigate the role of electrochemical potential in modulating molecular conductance.
- To elucidate the structural basis for high and low conductivity states.
Main Methods:
- Utilized scanning tunneling microscopy (STM) at the electrochemical interface.
- Applied controlled electrochemical potentials to the substrate supporting single Q-OPV molecules.
- Measured and compared conductance in different molecular states.
Main Results:
- Achieved reliable, reversible conductance switching in individual Q-OPV molecules.
- Observed a conductance ratio exceeding 40 between high- and low-conductivity states.
- Correlated the high-conductivity state with a fully conjugated hydroquinone-OPV structure.
- Attributed the low-conductivity state to disrupted electron delocalization in the quinone-OPV structure.
Conclusions:
- Single Q-OPV molecules can function as switchable electronic components.
- Electrochemical control provides a viable method for molecular switching.
- Molecular structure, specifically conjugation and delocalization, dictates conductivity states.
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