Tuning and Characterizing the Electronic Properties of a Single Molecule on a Graphene Device
(a) AFM image of a single F4TCNQ molecule anchored by alkane chains on a graphene FET device. (b) Molecular orbital and Dirac point energies versus FET gate voltage.
Reversible tuning and characterization of the charge state of an individual molecule at the surface of a graphene field effect transistor (FET).
Significance and Impact
A novel three-terminal device has allowed single molecules to be gated and imaged at the atomic scale.
- Measured the gate-tunable electronic structure of a single F4TCNQ molecule on a graphene field-effect transistor using scanning tunneling microscopy and spectroscopy.
- Characterized the chemical structure and adsorption geometry of the F4TCNQ molecule with single-bond resolution using non-contact atomic force microscopy.
- Observed a non-rigid shift in the molecule’s lowest unoccupied molecular orbital energy (LUMO) as a function of gate voltage consistent with theoretically predicted image-charge screening.