Synopsis: Sizing up domain walls in bilayer graphene

The mobility of charge carriers in epitaxial bilayer graphene may be limited by structural domains.
Synopsis figure
Illustration: H. Hibino et al., Phys. Rev. B (2009)

A material of interest for the next generation of electronic devices is “few-layer graphene,” a stack of a small number of graphene sheets. From an industrial perspective, preparing few-layer graphene by thermally decomposing silicon carbide (SiC) may be the easiest method for making carbon devices on a large scale. Unfortunately, the mobility of charge carriers in graphene prepared in this way appears to be lower than that in free-standing graphene. Therefore, the mass production of reliable electronic components requires a thorough understanding of what limits the mobility, and how to alleviate it.

In a paper appearing in Physical Review B, Hiroki Hibino and colleagues at NTT Corporation, in collaboration with Kyushu University, both in Japan, show that bilayer graphene grown on SiC forms two types of structural domains, differing by a 180° rotation. Three types of domain boundaries, with structures intermediate to those of the domains themselves, are attributed to “shifted stacking” of the layers. Hibino et al. propose that roughness at the SiC surface promotes lattice mismatch between adjacent graphene layers, causing strain and thus the stacking domains.

Although more work is needed to uncover the details of the epitaxial growth of graphene, and the precise effects of domain boundaries on its electronic transport, the results of Hibino et al. should steer future efforts in a productive direction. – Matthew Eager


Announcements

More Announcements »

Subject Areas

Graphene

Previous Synopsis

Atomic and Molecular Physics

Atoms in a lattice keep time

Read More »

Next Synopsis

Mesoscopics

A coincidence of errors

Read More »

Related Articles

Focus: New Form of Carbon Stores Lots of Gas
Graphene

Focus: New Form of Carbon Stores Lots of Gas

Carbon honeycomb, a new carbon structure, could store large amounts of hydrogen gas, which may benefit fuel cell technology. Read More »

Synopsis: Graphene Majoranas
Graphene

Synopsis: Graphene Majoranas

Graphene could host Majorana quasiparticles if brought into contact with a conventional superconductor. Read More »

Synopsis: Giving Graphene a Good Stretch  
Graphene

Synopsis: Giving Graphene a Good Stretch  

A specially shaped ribbon of single-layer carbon can produce a strong magnetic-like effect within the material when it is pulled on its ends. Read More »

More Articles