A Bond-Fluctuation Mechanism for Stochastic Switching in Wired Molecules

+ See all authors and affiliations

Science  30 May 2003:
Vol. 300, Issue 5624, pp. 1413-1416
DOI: 10.1126/science.1083825

You are currently viewing the abstract.

View Full Text


Stochastic on-off conductivity switching observed in phenylene-ethynylene oligomers has been explained in terms of changes in ring conformations, or electron localization, or both. We report the observation of stochastic on-off switching in the simplest of wired molecules: octanedithiol, decanedithiol, and dodecanedithiol bonded on an Au(111) surface. Stochastic switching was observed even when a top gold contact was pressed on by a conducting atomic force microscope tip at constant force. The rate of switching increased substantially at 60°C, a temperature at which these films are commonly annealed. Because such switching in alkanethiols is unlikely to be caused by internal molecular electronic changes and cannot be fully accounted for by breaking of the top contact, we argue that the cause is the well-known mobility of molecules tethered to gold via a thiol linkage.

View Full Text