Modeling graphene-based nanoelectromechanical devices

We report on a theoretical study of charge transport properties of graphene nanoribbons under external mechanical stress. The influence of mechanical forces on the ribbon conductance is shown to be strongly dependent on the ribbon edge symmetry, i.e., zigzag versus armchair. In contrast to zigzag-edge nanoribbons which remain robust against high strain deformations, a stretching-induced metal-semiconductor transition is obtained for armchair-edge configurations. Our results point out that armchair edge ribbons are consequently much better suited for electromechanical applications.

Figure 1

(Color online) (a) Representation of mechanical uniaxial forces applied on a nanoribbon. (b) Brillouin zone of a graphene and the allowed wave vectors of an AGNRs. Open circles represent the Fermi surface of the ribbon under mechanical stretching.

Figure 2

(Color online) Band structure and conductance for (a) relaxed and (b) strained AGNR-11 with a strain force of 100 nN and (c) relaxed and (d) strained ZGNR-10 with the same strain force.

Figure 3

(Color online) Contour plots of conductance as a function of Fermi energy and mechanical strain for (a) AGNR-11 and (b) ZGNR-10.