Reports

Chemically Derived, Ultrasmooth Graphene Nanoribbon Semiconductors

Xiaolin Li,^* Xinran Wang,^* Li Zhang, Sangwon Lee, Hongjie Dai

We developed a chemical route to produce graphene nanoribbons (GNR) with width below 10 nanometers, as well as single ribbons with varying widths along their lengths or containing lattice-defined graphene junctions for potential molecular electronics. The GNRs were solution-phase–derived, stably suspended in solvents with noncovalent polymer functionalization, and exhibited ultrasmooth edges with possibly well-defined zigzag or armchair-edge structures. Electrical transport experiments showed that, unlike single-walled carbon nanotubes, all of the sub–10-nanometer GNRs produced were semiconductors and afforded graphene field effect transistors with on-off ratios of about 10⁷ at room temperature.

Department of Chemistry and Laboratory for Advanced Materials, Stanford University, Stanford, CA 94305, USA.

^* These authors contributed equally to this work.

To whom correspondence should be addressed. E-mail: hdai@stanford.edu