Berkeley Lab Berkeley Lab A-Z Index Phone Book Jobs Search DOE

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.

Scientific Achievement
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.

Research Details

  • 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‚Äôs lowest unoccupied molecular orbital energy (LUMO) as a function of gate voltage consistent with theoretically predicted image-charge screening.

S. Wickenburg, J. Lu, J. Lischner, H.-Z. Tsai, A. A. Omrani, A. Riss, C. Karrasch, A. Bradley, H. S. Jung, R. Khajeh, D. Wong, K. Watanabe, T. Taniguchi, A. Zettl, A.H. Castro Neto, S. G. Louie, and M. F. Crommie, Nature Communications 7, 13553 (2016)