Hydrogen-free graphene edges

Selective etching of graphene edges by hydrogen plasma.

We devised a controlled hydrogen plasma reaction at 300 °C to etch graphene and graphene nanoribbons (GNRs) selectively at the edges over the basal plane. Atomic force microscope imaging showed that the etching rates for single-layer and few-layer (≥2 layers) graphene are 0.27 ± 0.05 nm/min and 0.10 ± 0.03 nm/min, respectively. Meanwhile, Raman spectroscopic mapping revealed no D band in the pl...

Excess energy and deformation along free edges of graphene nanoribbons

Change in the bonding environment at the free edges of graphene monolayer leads to excess edge energy and edge force, depending on the edge morphology zigzag or armchair . By using a reactive empirical bond-order potential and atomistic simulations, we show that the excess edge energy in free-standing graphene nanoribbons can be partially relaxed by both in-plane and out-of-plane deformation. T...

Raman spectroscopy of graphene edges.

Graphene edges are of particular interest since their orientation determines the electronic properties. Here we present a detailed Raman investigation of graphene flakes with edges oriented at different crystallographic directions. We also develop a real space theory for Raman scattering to analyze the general case of disordered edges. The position, width, and intensity of G and D peaks are stu...

Chemical Versus Thermal Folding of Graphene Edges

Using molecular dynamics (MD) simulations, we have investigated the kinetics of the graphene edge folding process. The lower limit of the energy barrier is found to be ~380 meV/Å (or about 800 meV per edge atom) and ~50 meV/Å (or about 120 meV per edge atom) for folding the edges of intrinsic clean single-layer graphene (SLG) and double-layer graphene (DLG), respectively. However, the edge fold...

Simulating impurities and edges in graphene