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A reversible molecular switch based on pattern-change in chlorobenzene and toluene on a Si(111)-(7x7) surface
Xuekun Lu1, John C Polanyi, Jody S Y Yang
1Department of Chemistry and Institute of Optical Sciences, University of Toronto, Toronto, Ontario M5S 3H6, Canada.
Abstract:
A reversible molecular switch is proposed, based on an observed change in a physisorbed pattern of chlorobenzene or toluene at Si(111)-(7x7), from "triangles" to "circles". Electronic excitation, at an applied surface voltage of Vs = -2.0 V, caused molecular migration, by one atomic site, from under the tip (switch "off"). Thereafter, the adsorbate pattern reverted thermally from circles to triangles (switch "on") across a measured activation barrier of Ea = 0.3 eV for chlorobenzene and 0.2 eV for toluene.
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