Electronic properties of grains and grain boundaries in graphene grown by chemical vapor deposition

We synthesize hexagonal shaped single-crystal graphene, with edges parallel to the zig-zag orientations, by ambient pressure CVD on polycrystalline Cu foils. We measure the electronic properties of such grains as well as of individual graphene grain boundaries, formed when two grains merged during the growth. The grain boundaries are visualized using Raman mapping of the DD band intensity, and we show that individual boundaries between coalesced grains impede electrical transport in graphene and induce prominent weak localization, indicative of intervalley scattering in graphene.

► Hexagonally shaped single layer graphene grains are grown by ambient pressure CVD.
► Graphene grain boundaries are formed when grains merge.
► Graphene grains and grain boundaries are visualized by Raman mapping of the intensities of its characteristic peaks.
► Electrical transport is impeded when carriers cross graphene grain boundaries.
► Weak localization is found for transport across an individual graphene grain boundary.