| AVS 60th International Symposium and Exhibition | |
| Graphene and Other 2D Materials Focus Topic | Monday Sessions |
| Session GR+EM+NS+SP+TF-MoA |
| Session: | Electronic Properties and Charge Transport in 2D Materials |
| Presenter: | D. Gunlycke, Naval Research Laboratory |
| Correspondent: | Click to Email |
The symmetry of the extended 5-5-8 line defect discovered in graphene in 2010 provides many interesting properties that could potentially be exploited in graphene-based electronic applications. Intrinsically, this line defect is approximately semitransparent, meaning that about 50% of carriers transmit through the line defect with the remaining 50% being subject to specular reflection. Another feature is that the transmission probability depends strongly on the valley of the incident carriers, making the line defect a valley filter, an essential component for valley-based electronics. Numerical simulations suggest that the line defect might offer ferromagnetically aligned local moments, which could also have implications for spin-based devices.
The properties of the line defect could be dramatically altered through chemical decoration. By turning sp2 bonds into sp3 bonds, the transmission probability is significantly reduced. Structures with two such line defects in a parallel configuration therefore exhibit confined graphene states, closely related to the states in zigzag nanoribbons. Unlike the nanoribbons, the railroad track structure formed by two parallel line defects allows carrier transport not only along the structure but also across it. The latter transverse transport occurs within resonance bands that closely trace the dispersion of the bands within the confinement. Owing to a dimensional crossover, the resonance bands must terminate, which leaves behind a transport gap. This transport gap could be used in lateral graphene-based resonant tunneling transistors.
This work was supported by the Office of Naval Research, directly and through the Naval Research Laboratory.