ABSTRACT
Descriptions of transport in single-molecule devices often focus on
the properties of the molecular backbone, the energy separation
between the highest occupied molecular orbital (HOMO) and the
lowest unoccupied molecular orbital (LUMO), molecular conjuga-
tion, device size, or the addition of ions to the molecule. Although
these features are undeniably important, the conductance, device
lifetime, mechanical stability, and energy-level alignment all depend
critically upon the molecule-electrode contact. The ability to create
stable, long-lifetime, and reproducible contacts between a single
molecule and two electrodes is necessary to enable technologically
practical devices, but these capabilities also allow the exploration
of unique device paradigms where mechanically perturbing a
single molecule controls the electronic system. This chapter will
discuss the molecule-electrode contact by developing a simple
transport model to demonstrate how contact affects the transport
properties, explore the use of various molecule-electrode linker
chemistries, and also discuss controlling the molecule-electrode
contact mechanically to control the device’s charge transport
properties.
