Electronic Transport Through Graphene Nanoribbons with Stone-Wales Reconstruction at Edges and Interfaces

Abstract

In this paper, we study the conductance of the graphene nanoribbons(GNRs) in the presence of the Stone-Wales(S-W) reconstruction, using the transfer matrix method. The ribbon is connected with semi-infinite quantum wires as the leads. The S-W reconstruction occurs on the edges and the interfaces between the electrodes and ribbon. When the reconstruction occurs on the edges, the conductance is suppressed considerably if the gate voltage Vg takes intermediate values around |Vg| ∼ t0(t0 being the hopping amplitude of grahene) in both positive and negative energy regions. In contrast, if Vg is close to the Dirac point or the band edges, the conductance is relatively insensitive to the edge reconstruction. The effect of edge reconstruction become less important with increasing ribbon width as expected. The S-W reconstruction occurs also possibly at the interfaces. In this case, the reconstruction suppresses identically the conductance in the entire range of Vg for armchair GNRs. For the zigzag GNRs, the conductance is strongly suppressed in the negative energy region, however the change of the conductance is relatively small in the positive energy region. We also analyze the transmission coefficients as functions of the channel index(the transverse momentum ky of the leads) for the neutral armchair GNRs with interface defects. Interestingly, there are two transmission peaks appearing at ky = π/3 and ky = 2π/3 due to the unit cell doubling.

Effects of Stone-Wales Defect Position in Graphene Nanoribbon Field-Effect Transistor

“…This process is accompanied with a structural relaxation until the change in total energy and forces on carbon atoms become less than 10 -4 eV and 10 -3 eV/Å respectively [7]. As matter of fact, it is found that such a dislocation experimentally can be created by irradiation, chemical treatments and during a rapid quench from high temperature [8][9][10][11].…”