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Molecular rectification in a metal-insulator-metal junction based on self-assembled monolayers
Michael L Chabinyc1, Xiaoxi Chen, R Erik Holmlin
1Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.
Journal of the American Chemical Society
|September 26, 2002
Summary
This study demonstrates current rectification in a novel electrical junction. A single redox center within a metal-insulator-metal junction, formed by self-assembled monolayers, enables this rectification without requiring a fixed dipole.
Area of Science:
- Materials Science
- Nanotechnology
- Electrical Engineering
Background:
- Metal-insulator-metal junctions are crucial for electronic devices.
- Self-assembled monolayers (SAMs) offer precise control over interfacial properties.
- Current rectification is a fundamental electronic function.
Purpose of the Study:
- To investigate current rectification in a novel metal-insulator-metal junction.
- To explore the role of a redox center in rectification.
- To determine if a fixed dipole is necessary for rectification.
Main Methods:
- Fabrication of electrical junctions using two distinct self-assembled monolayers (SAMs) on silver/gold and mercury.
- Characterization of electrical properties via current-voltage measurements.
- Systematic variation of alkanethiol chain length in the mercury-supported SAM.
Main Results:
- The fabricated junction exhibited current rectification, with a conductivity ratio of 9 +/- 2 at 1V for a specific alkanethiol chain length.
- Rectification efficiency increased as the alkanethiol chain length decreased.
- Demonstrated rectification solely due to an asymmetrically placed redox center.
Conclusions:
- A single, asymmetrically placed redox center can induce current rectification in a metal-insulator-metal junction.
- Rectification is achievable without relying on a fixed dipole within the insulating layer.
- This work offers new insights into designing rectifying molecular electronic components.
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