Charge transfer and optical phonon mixing in few-layer graphene chemically doped with sulfuric acid

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	Charge transfer and optical phonon mixing in few-layer graphene chemically doped with sulfuric acid
	Tan PH
刊名	physical review b
	2010
卷号	82 期号:24 页码:article no.245423
关键词	RAMAN-SPECTROSCOPY BILAYER GRAPHENE GRAPHITE SCATTERING SPECTRA CARBON FILMS
ISSN号	1098-0121
通讯作者	zhao, wj, chinese acad sci, inst semicond, state key lab superlattices & microstruct, beijing 100083, peoples r china. phtan@semi.ac.cn
学科主题	半导体物理
收录类别	SCI
资助信息	national natural science foundation of china [10934007, 10874177]; special funds for the major state basic research of china [2009cb929300]
语种	英语
公开日期	2011-07-05 ; 2011-07-15
附注	chemical doping is expected to substantially increase the density of free charge carriers by charge transfer and modify the fermi level and screening effect of doped materials. here, along with raman identification of 3 and 4 graphene layers by a 633-nm laser excitation, we investigated charge transfer and optical phonon mixing in few layer graphenes in detail by utilizing sulfuric acid as an electron-acceptor dopant. sulfuric acid molecules are found to be only physically adsorbed on the surface layers of graphenes without intercalations. the top and bottom layers of bilayer graphene can be intentionally doped differently by concentrated sulfuric acid. the difference of the hole doping between the top and bottom layers results in phonon mixing of symmetric and antisymmetric modes in bilayer graphene. the raman frequency evolution with the doping level is in agreement with recent ab initio density-functional theory calculations [p. gava, m. lazzeri, a. m. saitta, and f. mauri, phys. rev. b 80, 155422 (2009)]. chemical doping by adsorption-induced charge transfer offers a way to study the electronic and vibrational behaviors of few layer graphenes at high-carrier concentration.
内容类型	期刊论文
源URL	[http://ir.semi.ac.cn/handle/172111/20921]
专题	半导体研究所_半导体超晶格国家重点实验室
推荐引用方式 GB/T 7714	Tan PH. Charge transfer and optical phonon mixing in few-layer graphene chemically doped with sulfuric acid[J]. physical review b,2010,82(24):article no.245423.
APA	Tan PH.(2010).Charge transfer and optical phonon mixing in few-layer graphene chemically doped with sulfuric acid.physical review b,82(24),article no.245423.
MLA	Tan PH."Charge transfer and optical phonon mixing in few-layer graphene chemically doped with sulfuric acid".physical review b 82.24(2010):article no.245423.