Journal article
Ferrocenylundecanethiol self-assembled monolayer charging correlates with negative differential resistance measured by conducting probe atomic force microscopy
Journal of the American Chemical Society, Vol.127(20), pp.7647-7653
2005
DOI: 10.1021/ja0514491
PMID: 15898817
Abstract
Electrical and mechanical properties of metal-molecule-metal junctions formed between Au-supported self-assembled monolayers (SAMs) of electroactive 11-ferrocenylundecanethiol (FcC11SH) and a Pt-coated atomic force microscope (AFM) tip have been measured using a conducting probe (CP) AFM in insulating alkane solution. Simultaneous and independent measurements of currents and bias-dependent adhesion forces under different applied tip biases between the conductive AFM probe and the FcC11SH SAMs revealed reversible peak-shaped current-voltage (I-V) characteristics and correlated maxima in the potential-dependent adhesion force. Trapped positive charges in the molecular junction correlate with high conduction in a feature showing negative differential resistance. Similar measurements on an electropassive 1-octanethiol SAM did not show any peaks in either adhesion force or I-V curves. A mechanism involving two-step resonant hole transfer through the occupied molecular orbitals (MOs) of ferrocene end groups via sequential oxidation and subsequent reduction, where a hole is trapped by the phonon relaxation, is proposed to explain the observed current-force correlation. These results suggest a new approach to probe charge-transfer involving electroactive groups on the nanoscale by measuring the adhesion forces as a function of applied bias in an electrolyte-free environment. © 2005 American Chemical Society.
Details
- Title: Subtitle
- Ferrocenylundecanethiol self-assembled monolayer charging correlates with negative differential resistance measured by conducting probe atomic force microscopy
- Creators
- Alexei V Tivanskit - Contribution from the Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United StatesGilbert C Walker - Department of Chemistry, University of Toronto, Toronto, Ontario, M5S 3H6, CanadaAlexei V Tivanski - Chemistry
- Resource Type
- Journal article
- Publication Details
- Journal of the American Chemical Society, Vol.127(20), pp.7647-7653
- Publisher
- American Chemical Society
- DOI
- 10.1021/ja0514491
- PMID
- 15898817
- ISSN
- 0002-7863
- eISSN
- 1520-5126
- Language
- English
- Date published
- 2005
- Academic Unit
- Chemistry
- Record Identifier
- 9984216726402771
Metrics
16 Record Views