title: Dimensional crossover of thermal transport in few-layer graphene.
abstract: Graphene, in addition to its unique electronic and optical properties, reveals unusually high thermal conductivity. The fact that the thermal conductivity of large enough graphene sheets should be higher than that of basal planes of bulk graphite was predicted theoretically by Klemens. However, the exact mechanisms behind the drastic alteration of a material's intrinsic ability to conduct heat as its dimensionality changes from two to three dimensions remain elusive. The recent availability of high-quality few-layer graphene (FLG) materials allowed us to study dimensional crossover experimentally. Here we show that the room-temperature thermal conductivity changes from approximately 2,800 to approximately 1,300 W m(-1) K(-1) as the number of atomic planes in FLG increases from 2 to 4. We explained the observed evolution from two dimensions to bulk by the cross-plane coupling of the low-energy phonons and changes in the phonon Umklapp scattering. The obtained results shed light on heat conduction in low-dimensional materials and may open up FLG applications in thermal management of nanoelectronics.
authors.forename: Suchismita
authors.initials: S
authors.lastname: Ghosh
authors.forename: Wenzhong
authors.initials: W
authors.lastname: Bao
authors.forename: Denis L
authors.initials: DL
authors.lastname: Nika
authors.forename: Samia
authors.initials: S
authors.lastname: Subrina
authors.forename: Evghenii P
authors.initials: EP
authors.lastname: Pokatilov
authors.forename: Chun Ning
authors.initials: CN
authors.lastname: Lau
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Balandin
references.citation: Phys Rev Lett. 2009 May 22;102(20):206410
references.pmid: 19519053
references.citation: Phys Rev Lett. 2005 Aug 26;95(9):096105
references.pmid: 16197233
references.citation: Phys Rev Lett. 2006 Nov 3;97(18):187401
references.pmid: 17155573
references.citation: Nature. 2005 Nov 10;438(7065):201-4
references.pmid: 16281031
references.citation: Phys Rev Lett. 2001 Nov 19;87(21):215502
references.pmid: 11736348
references.citation: Phys Rev Lett. 2008 Aug 15;101(7):075903
references.pmid: 18764555
references.citation: Nano Lett. 2007 Sep;7(9):2645-9
references.pmid: 17718584
references.citation: Science. 2004 Oct 22;306(5696):666-9
references.pmid: 15499015
references.citation: Phys Rev Lett. 2006 May 26;96(20):204303
references.pmid: 16803175
references.citation: Nano Lett. 2008 Mar;8(3):902-7
references.pmid: 18284217
references.citation: Phys Rev E Stat Nonlin Soft Matter Phys. 2006 Dec;74(6 Pt 1):062101
references.pmid: 17280104
references.citation: Phys Rev Lett. 2000 May 15;84(20):4613-6
references.pmid: 10990753
references.citation: Science. 2008 Jun 6;320(5881):1308
references.pmid: 18388259
references.citation: Nature. 2008 Jan 10;451(7175):163-7
references.pmid: 18185582
references.citation: Phys Rev Lett. 2002 Nov 11;89(20):200601
references.pmid: 12443466
references.citation: Nano Lett. 2009 Jan;9(1):346-52
references.pmid: 19099462
references.citation: Nat Nanotechnol. 2009 Sep;4(9):562-6
references.pmid: 19734927
references.citation: Nano Lett. 2009 Jul;9(7):2730-5
references.pmid: 19499898
references.citation: Nature. 2005 Nov 10;438(7065):197-200
references.pmid: 16281030