Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9594740 | Surface Science | 2005 | 13 Pages |
Abstract
Scanning tunneling microscopy and surface photovoltage images are reported for isolated dye molecules on the GaAs(1Â 1Â 0) surface. Profound differences in the molecular images are observed for different experimental conditions. Specifically, contrast variations with changing bias polarity and magnitude, and for different substrate doping type are examined. Several mechanisms are considered to describe the observations including direct and resonant tunneling, and switching of charges between molecular states in the band gap and the energy bands of the GaAs. This treatment enables both assignment of the molecular charge state polarity, and clarification of the mechanism for current flow.
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Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Iftach Nevo, Sidney R. Cohen,