Superstructural defects and superlattice domains in stacked graphene

Abstract

Recently there has been interest in two-dimensional graphene-based superstructures, such as twisted bilayer or trilayer graphene or graphene on hexagonal boron nitride, stacked one on top of the other. These superstructures are expected to have electronic and optical properties that depend on even small changes in the twist angles. By structural mapping in the micrometer scale, we demonstrate that superstructures consist of stacking-induced 'superlattice domains'. The rotational disorder between domains created by the superstructural defects, such as wrinkles, folds and grain boundaries, and guest species intercalated between stacked layers, was analyzed at a resolution of sub-one degree. This comprehensive approach provides crucial structural information on graphene-based superstructures.