title: Direct visualization of large-area graphene domains and boundaries by optical birefringency.
abstract: The boundaries between domains in single-layer graphene strongly influence its electronic properties. However, existing approaches for domain visualization, which are based on microscopy and spectroscopy, 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.
authors.affiliation: National Research Lab, for Organic Opto-Electronic Materials, Department of Chemical and Biomolecular Eng. (BK-21), Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
authors.forename: Dae Woo
authors.initials: DW
authors.lastname: Kim
authors.forename: Yun Ho
authors.initials: YH
authors.lastname: Kim
authors.forename: Hyeon Su
authors.initials: HS
authors.lastname: Jeong
authors.forename: Hee-Tae
authors.initials: HT
authors.lastname: Jung
references.citation: Science. 1989 Jul 7;245(4913):43-5
references.pmid: 17787991
references.citation: Nat Nanotechnol. 2010 Aug;5(8):574-8
references.pmid: 20562870
references.citation: Nano Lett. 2010 Nov 10;10(11):4328-34
references.pmid: 20957985
references.citation: Nano Lett. 2007 Sep;7(9):2707-10
references.pmid: 17665963
references.citation: ACS Nano. 2011 Mar 22;5(3):2142-6
references.pmid: 21280616
references.citation: Nat Nanotechnol. 2008 Apr;3(4):206-9
references.pmid: 18654504
references.citation: Science. 2009 Jun 5;324(5932):1312-4
references.pmid: 19423775
references.citation: Nature. 2009 Feb 5;457(7230):706-10
references.pmid: 19145232
references.citation: Nat Mater. 2010 Oct;9(10):806-9
references.pmid: 20729847
references.citation: Phys Rev Lett. 2006 Nov 3;97(18):187401
references.pmid: 17155573
references.citation: Nano Lett. 2011 Jan 12;11(1):16-22
references.pmid: 21128677
references.citation: Nature. 2011 Jan 20;469(7330):389-92
references.pmid: 21209615
references.citation: Nano Lett. 2010 Sep 8;10(9):3512-6
references.pmid: 20677798