title: Atomic-scale transport in epitaxial graphene.
abstract: The high carrier mobility of graphene is key to its applications, and understanding the factors that limit mobility is essential for future devices. Yet, despite significant progress, mobilities in excess of the 2×10(5) cm(2) V(-1) s(-1) demonstrated in free-standing graphene films have not been duplicated in conventional graphene devices fabricated on substrates. Understanding the origins of this degradation is perhaps the main challenge facing graphene device research. Experiments that probe carrier scattering in devices are often indirect, relying on the predictions of a specific model for scattering, such as random charged impurities in the substrate. Here, we describe model-independent, atomic-scale transport measurements that show that scattering at two key defects--surface steps and changes in layer thickness--seriously degrades transport in epitaxial graphene films on SiC. These measurements demonstrate the strong impact of atomic-scale substrate features on graphene performance.
authors.forename: Shuai-Hua
authors.initials: SH
authors.lastname: Ji
authors.forename: J B
authors.initials: JB
authors.lastname: Hannon
authors.forename: R M
authors.initials: RM
authors.lastname: Tromp
authors.forename: V
authors.initials: V
authors.lastname: Perebeinos
authors.forename: J
authors.initials: J
authors.lastname: Tersoff
authors.forename: F M
authors.initials: FM
authors.lastname: Ross
references.citation: Phys Rev Lett. 2007 May 4;98(18):186806
references.pmid: 17501596
references.citation: Nat Mater. 2007 Oct;6(10):770-5
references.pmid: 17828279
references.citation: Rev Sci Instrum. 2008 Aug;79(8):083704
references.pmid: 19044354
references.citation: Nanotechnology. 2009 Nov 4;20(44):445704
references.pmid: 19809118
references.citation: Phys Rev Lett. 2006 Dec 1;97(22):226801
references.pmid: 17155824
references.citation: Nano Lett. 2010 May 12;10(5):1559-62
references.pmid: 20397734
references.citation: Nature. 2005 Nov 10;438(7065):201-4
references.pmid: 16281031
references.citation: Nature. 2009 Nov 19;462(7271):339-41
references.pmid: 19924211
references.citation: Nat Nanotechnol. 2008 Apr;3(4):206-9
references.pmid: 18654504
references.citation: Phys Rev Lett. 2008 Aug 29;101(9):096802
references.pmid: 18851636
references.citation: Nature. 2005 Nov 10;438(7065):197-200
references.pmid: 16281030
references.citation: Nat Nanotechnol. 2010 Oct;5(10):722-6
references.pmid: 20729834
references.citation: Phys Rev Lett. 2007 May 18;98(20):206802
references.pmid: 17677726
references.citation: Phys Rev Lett. 2009 Mar 13;102(10):106104
references.pmid: 19392131
references.citation: Science. 2007 Jul 13;317(5835):219-22
references.pmid: 17626878
references.citation: Nat Nanotechnol. 2008 Aug;3(8):491-5
references.pmid: 18685637
references.citation: Science. 2006 May 26;312(5777):1191-6
references.pmid: 16614173
references.citation: Nano Lett. 2011 Jan 12;11(1):16-22
references.pmid: 21128677
references.citation: Nano Lett. 2009 Apr;9(4):1588-92
references.pmid: 19278211
references.citation: Nano Lett. 2010 Nov 10;10(11):4285-94
references.pmid: 20879723