Dae Woo Kim Yun Ho Kim Hyun Su Jeong Hee-Tae Jung published online: 20 Nov. 2011

doi: 10.1038/nnano 2011.198

The boundaries between domains in single-layer graphene1–4strongly influence its electronic properties5–12. However, existing
approaches for domain visualization, which are based onmicroscopy and spectroscopy2,12–16, are only effective for
domains that are less than a few micrometres in size. Here,we report a simple method for the visualization of arbitrarily
large graphene domains by imaging the birefringence of a graphene surface covered with nematic liquid crystals. The method
relies on a correspondence between the orientation of the liquid crystals and that of the underlying graphene, which we use to
determine the boundaries of macroscopic domains.