Imaging stacking order in few-layer graphene.
Few-layer graphene (FLG) has been predicted to exist in various crystallographic stacking sequences, which can strongly influence the material's electronic properties. We demonstrate an accurate and efficient method to characterize stacking order in FLG using the distinctive features of the Raman 2D-mode. Raman imaging allows us to visualize directly the spatial distribution of Bernal (ABA) and rhombohedral (ABC) stacking in tri- and tetralayer graphene. We find that 15% of exfoliated graphene tri- and tetralayers is composed of micrometer-sized domains of rhombohedral stacking, rather than of usual Bernal stacking. These domains are stable and remain unchanged for temperatures exceeding 800 °C.
Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, United States.
Chun Hung
CH
Lui
Zhiqiang
Z
Li
Zheyuan
Z
Chen
Paul V
PV
Klimov
Louis E
LE
Brus
Tony F
TF
Heinz