Making electrical contacts to molecular monolayers

X. D. Cui, X. Zarate, J. Tomfohr, O. F. Sankey, A. Primak, Ana Moore, Thomas Moore, D. Gust, G. Harris, Stuart Lindsay

Research output: Contribution to journalArticlepeer-review

307 Scopus citations


Electrical contacts between a metal probe and molecular monolayers have been characterized using conducting atomic force microscopy in an inert environment and in a voltage range that yields reversible current-voltage data. The current through alkanethiol monolayers depends on the contact force in a way that is accounted for by the change of chain-to-chain tunnelling with film thickness. The electronic decay constant, βN, was obtained from measurements as a function of chain length at constant force and bias, yielding βN = 0.8 ± 0.2 per methylene over a ± 3 V range. Current-voltage curves are difficult to reconcile with this almost constant value. Very different results are obtained when a gold tip contacts a 1, 8-octanedithiol film. Notably, the current-voltage curves are often independent of contact force. Thus the contact may play a critical role both in the nature of charge transport and the shape of the current-voltage curve.

Original languageEnglish (US)
Pages (from-to)5-14
Number of pages10
Issue number1
StatePublished - Feb 2002

ASJC Scopus subject areas

  • Bioengineering
  • General Chemistry
  • General Materials Science
  • Mechanics of Materials
  • Mechanical Engineering
  • Electrical and Electronic Engineering


Dive into the research topics of 'Making electrical contacts to molecular monolayers'. Together they form a unique fingerprint.

Cite this