Electrostatic deposition of graphene in a gaseous environment: A deterministic route to synthesize rolled graphenes?

The synthesis of single-wall carbon nanotubes (SWCNTs) of desired diameters and chiralities is critical to the design of nanoscale electronic devices with desired properties.1-6 The existing methods are based on self-assembly, 7-16 therefore lacking the control over their diameters and chiralities. The present work reports a direct route to roll graphene. Specifically, we found that the electrostatic deposition of graphene yielded: (i) flat graphene layers under high vacuum (10-7 Torr), (ii) completely scrolled graphene under hydrogen atmosphere, (iii) partially scrolled graphene under nitrogen atmosphere, and (iv) no scrolling for helium atmospheres. Our study shows that the application of the electrostatic field facilitates the rolling of graphene sheets exposed to appropriate gases and allows the rolling of any size graphene. The technique proposed here, in conjunction with a technique that produces graphene nanoribbons (GNRs) of uniform widths, will have significant impact on the development of carbon nanotube based devices. Furthermore, the present technique may be applied to obtain tubes/scrolls of other layered materials.