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Michael S. Fuhrer

Bio: Michael S. Fuhrer is an academic researcher from Monash University. The author has contributed to research in topics: Graphene & Carbon nanotube. The author has an hindex of 70, co-authored 309 publications receiving 26802 citations. Previous affiliations of Michael S. Fuhrer include University of California & University of New South Wales.


Papers
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TL;DR: It is shown that electron-acoustic phonon scattering is indeed independent of n, and contributes only 30 Omega to graphene's room-temperature resistivity, and its magnitude, temperature dependence and carrier-density dependence are consistent with extrinsic scattering by surface phonons at the SiO2 substrate.
Abstract: The linear dispersion relation in graphene gives rise to a surprising prediction: the resistivity due to isotropic scatterers, such as white-noise disorder or phonons, is independent of carrier density, n. Here we show that electron-acoustic phonon scattering is indeed independent of n, and contributes only 30 Omega to graphene's room-temperature resistivity. At a technologically relevant carrier density of 1 x1012 cm-2, we infer a mean free path for electron-acoustic phonon scattering of >2 microm and an intrinsic mobility limit of 2 x 105 cm2 V-1 s-1. If realized, this mobility would exceed that of InSb, the inorganic semiconductor with the highest known mobility ( approximately 7.7 x 104 cm2 V-1 s-1; ref. 9) and that of semiconducting carbon nanotubes ( approximately 1 x 105 cm2 V-1 s-1; ref. 10). A strongly temperature-dependent resistivity contribution is observed above approximately 200 K (ref. 8); its magnitude, temperature dependence and carrier-density dependence are consistent with extrinsic scattering by surface phonons at the SiO2 substrate and limit the room-temperature mobility to approximately 4 x 104 cm2 V-1 s-1, indicating the importance of substrate choice for graphene devices.

2,947 citations

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TL;DR: In this article, a carbon nanotube transistors with channel lengths exceeding 300 microns have been fabricated, where the carrier transport is diffusive and the channel resistance dominates the transport.
Abstract: Semiconducting carbon nanotube transistors with channel lengths exceeding 300 microns have been fabricated. In these long transistors, carrier transport is diffusive and the channel resistance dominates the transport. Transport characteristics are used to extract the field-effect mobility (79 000 cm2/Vs) and estimate the intrinsic mobility (>100 000 cm2/Vs) at room temperature. These values exceed those for all known semiconductors, which bodes well for application of nanotubes in high-speed transistors, single- and few-electron memories, and chemical/biochemical sensors.

1,510 citations

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TL;DR: Atomic structures and nanoscale morphology of graphene-based electronic devices are revealed for the first time and a strong spatially dependent perturbation is revealed which breaks the hexagonal lattice symmetry of the graphitic lattice.
Abstract: We employ scanning probe microscopy to reveal atomic structures and nanoscale morphology of graphene-based electronic devices (i.e., a graphene sheet supported by an insulating silicon dioxide substrate) for the first time. Atomic resolution scanning tunneling microscopy images reveal the presence of a strong spatially dependent perturbation, which breaks the hexagonal lattice symmetry of the graphitic lattice. Structural corrugations of the graphene sheet partially conform to the underlying silicon oxide substrate. These effects are obscured or modified on graphene devices processed with normal lithographic methods, as they are covered with a layer of photoresist residue. We enable our experiments by a novel cleaning process to produce atomically clean graphene sheets.

1,497 citations

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TL;DR: In this paper, a systematic study of the influence of scattering from impurities on the peculiar electronic properties of graphene is conducted by monitoring changes in electronic characteristics of initially clean graphene, by depositing potassium atoms onto its surface in ultrahigh vacuum.
Abstract: Valuable insight into the influence of scattering from impurities on the peculiar electronic properties of graphene are gained by a systematic study of how its conductivity changes with increasing concentration of potassium ions deposited on its surface. Since the initial demonstration of the ability to experimentally isolate a single graphene sheet1, a great deal of theoretical work has focused on explaining graphene’s unusual carrier-density-dependent conductivity σ(n), and its minimum value (σmin) of nearly twice the quantum unit of conductance (4e2/h) (refs 1, 2, 3, 4, 5, 6). Potential explanations for such behaviour include short-range disorder7,8,9,10, ‘ripples’ in graphene’s atomic structure11,12 and the presence of charged impurities7,8,13,14,15,16,17,18. Here, we conduct a systematic study of the last of these mechanisms, by monitoring changes in electronic characteristics of initially clean graphene19 as the density of charged impurities (nimp) is increased by depositing potassium atoms onto its surface in ultrahigh vacuum. At non-zero carrier density, charged-impurity scattering produces the widely observed linear dependence1,2,3,4,5,6 of σ(n). More significantly, we find that σmin occurs not at the carrier density that neutralizes nimp, but rather the carrier density at which the average impurity potential is zero15. As nimp increases, σmin initially falls to a minimum value near 4e2/h. This indicates that σmin in the present experimental samples1,2,3,4,5,6 is governed not by the physics of the Dirac point singularity20,21, but rather by carrier-density inhomogeneities induced by the potential of charged impurities6,8,14,15.

1,287 citations

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TL;DR: In this paper, the fabrication and electronic properties of devices based on individual carbon nanotubes are reviewed, and both metallic and semiconducting SWNTs are found to possess electrical characteristics that compare favorably to the best electronic materials available.
Abstract: Single-walled carbon nanotubes (SWNTs) have emerged as a very promising new class of electronic materials. The fabrication and electronic properties of devices based on individual SWNTs are reviewed. Both metallic and semiconducting SWNTs are found to possess electrical characteristics that compare favorably to the best electronic materials available. Manufacturability issues, however, remain a major challenge.

1,206 citations


Cited by
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TL;DR: In this paper, the basic theoretical aspects of graphene, a one-atom-thick allotrope of carbon, with unusual two-dimensional Dirac-like electronic excitations, are discussed.
Abstract: This article reviews the basic theoretical aspects of graphene, a one-atom-thick allotrope of carbon, with unusual two-dimensional Dirac-like electronic excitations. The Dirac electrons can be controlled by application of external electric and magnetic fields, or by altering sample geometry and/or topology. The Dirac electrons behave in unusual ways in tunneling, confinement, and the integer quantum Hall effect. The electronic properties of graphene stacks are discussed and vary with stacking order and number of layers. Edge (surface) states in graphene depend on the edge termination (zigzag or armchair) and affect the physical properties of nanoribbons. Different types of disorder modify the Dirac equation leading to unusual spectroscopic and transport properties. The effects of electron-electron and electron-phonon interactions in single layer and multilayer graphene are also presented.

20,824 citations

28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: This work reviews the historical development of Transition metal dichalcogenides, methods for preparing atomically thin layers, their electronic and optical properties, and prospects for future advances in electronics and optoelectronics.
Abstract: Single-layer metal dichalcogenides are two-dimensional semiconductors that present strong potential for electronic and sensing applications complementary to that of graphene.

13,348 citations