Graphenes as Potential Material for Electronics

Wu, Jishan; Pisula, Wojciech; Müllen, Kläus

doi:10.1021/cr068010r

Cited by 2,589 publications

(1,679 citation statements)

References 201 publications

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“…The results are shown in [ [ + ] = particularly high stability, high melting point, and low chemical reactivity. 64 In each of the three The Clar formula for a given molecule or a periodic cell of a crystal is not necessarily unique.…”

Section: Methodsmentioning

confidence: 99%

Clar’s Theory, π-Electron Distribution, and Geometry of Graphene Nanoribbons

et al. 2010

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We show that Clar's theory of the aromatic sextet is a simple and powerful tool to predict the stability, the π-electron distribution, the geometry, the electronic/magnetic structure of graphene nanoribbons with different hydrogen edge terminations. We use density functional theory to obtain the equilibrium atomic positions, simulated scanning tunneling microscopy (STM) images, edge energies, band gaps, and edge-induced strains of graphene ribbons that we analyze in terms of Clar formulas. Based on their Clar representation, we propose a classification scheme for graphene ribbons that groups configurations with similar bond length alternations, STM patterns, and Raman spectra. Our simulations show how STM images and Raman spectra can be used to identify the type of edge termination.

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Section: Methodsmentioning

confidence: 99%

Clar’s Theory, π-Electron Distribution, and Geometry of Graphene Nanoribbons

et al. 2010

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“…Amongst the plethora of organic semiconductors available, polycyclic aromatic hydrocarbons (PAHs) have attracted increasing attention 1, 2, 3, 4, 5, 6. With respect to infinite graphene, PAHs show nonzero tunable bandgaps and are thus of use as chromophores in antennae7, 8, 9, 10, 11, 12 or emissive molecular architectures13, 14, 15, 16, 17, 18, 19 and in general in all optoelectronic applications requiring a tunable semiconducting material 6, 20.…”

Section: Introductionmentioning

confidence: 99%

“…With respect to infinite graphene, PAHs show nonzero tunable bandgaps and are thus of use as chromophores in antennae7, 8, 9, 10, 11, 12 or emissive molecular architectures13, 14, 15, 16, 17, 18, 19 and in general in all optoelectronic applications requiring a tunable semiconducting material 6, 20. By exploiting organic synthetic tools,21, 22 one can tune the molecular HOMO–LUMO gap8 by 1) changing the size and edge of the carbon‐based aromatic framework; 2) varying the molecular planarity upon insertion of bulky substituents or bridging chains; 3) changing the aromatic properties of the constituent monomeric units; 4) varying the peripheral functionalization through the insertion of electron‐donating or electron‐ withdrawing substituents; 5) enclosing structural defects; 6) promoting supramolecular interactions between individual molecules governing their organization into a condensed phase, and 7) replacing selected carbon atoms by isostructural and isoelectronic analogues (i.e., doping).…”

Section: Introductionmentioning

confidence: 99%

Tailoring Colors by O Annulation of Polycyclic Aromatic Hydrocarbons

Miletić

Fermi

Orfanos

et al. 2017

Chemistry A European J

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The synthesis of O‐doped polyaromatic hydro‐ carbons in which two polycyclic aromatic hydrocarbon sub units are bridged through one or two O atoms has been achieved. This includes high‐yield ring‐closure key steps that, depending on the reaction conditions, result in the formation of furanyl or pyranopyranyl linkages through intramolecular C−O bond formation. Comprehensive photophysical measurements in solution showed that these compounds have exceptionally high emission yields and tunable absorption properties throughout the UV/Vis spectral region. Electrochemical investigations showed that in all cases O annulation increases the electron‐donor capabilities by raising the HOMO energy level, whereas the LUMO energy level is less affected. Moreover, third‐order nonlinear optical (NLO) measurements on solutions or thin films containing the dyes showed very good values of the second hyperpolarizability. Importantly, poly(methyl methacrylate) films containing the pyranopyranyl derivatives exhibited weak linear absorption and NLO absorption compared to the nonlinearity and NLO refraction, respectively, and thus revealed them to be exceptional organic materials for photonic devices.

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“…Having many similarities to carbon nanotubes (CNTs) in structure and property, including its high aspect ratio (the ratio of lateral size to thickness), large surface, rich electronic states, and good mechanical properties, graphene is an attractive candidate for potential uses in many areas where the CNTs have been exploited. Superior to CNTs, the one atomic-thick graphene sheets with a 2D planar geometry will further facilitate electron transport, 16 and hence the more effective electrode materials. …”

mentioning

confidence: 99%

Nitrogen-Doped Graphene as Efficient Metal-Free Electrocatalyst for Oxygen Reduction in Fuel Cells

et al. 2010

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. ¶ These authors contributed equally.P latinum (Pt) nanoparticles have long been regarded as the best catalyst for the oxygen reduction reaction (ORR) in fuel cells, though the Pt-based electrode still suffers from its susceptibility to timedependent drift and CO deactivation. 1Ϫ3 Furthermore, the high cost of the Pt catalysts, together with the limited reserves of Pt in nature, has been shown to be the major "showstopper" to mass market fuel cells for commercial applications. That is why the large-scale practical application of fuel cells has not been realized, though alkaline fuel cells with platinum as an ORR electrocatalyst were developed for the Apollo lunar mission in the 1960s. 4 Along with recent intensive research efforts in reducing or replacing Ptbased electrodes in fuel cells, 3,5Ϫ11 we have found that vertically aligned nitrogencontaining carbon nanotubes (VA-NCNTs) produced by pyrolysis of iron(II) phthalocyanine (a metal heterocyclic molecule containing nitrogen), 12 in either the presence or absence of additional NH 3 vapor, 3 could act as effective metal-free ORR electrocatalysts. The metal-free VA-NCNTs were shown to catalyze a four-electron ORR process free from CO "poisoning" with a 3-time higher electrocatalytic activity, smaller crossover effect, and better long-term operation stability than that of commercially available Pt-based electrodes (C2Ϫ20, 20% platinumonVulcanXC-72R; E-TEK) in alkaline electrolytes. 3 On the basis of the experimental observations and quantum mechanics calculations, we attributed the improved catalytic performance to the electronaccepting ability of the nitrogen atoms, which creates a net positive charge on adjacent carbon atoms in the nanotube carbon plane of VA-NCNTs to readily attract electrons from the anode for facilitating the ORR. 3 Uncovering this new ORR mechanism in nitrogen-doped carbon nanotube electrodes is significant as the same principle could be applied to the development of various other metal-free efficient ORR catalysts for fuel cell applications.The recent discovery of graphene has opened up a new era of 2-dimensional (2D) fundamental science and potential technology. 13Ϫ15 As mother of all graphitic forms, graphene is a building block for carbon materials of all other dimensionalities, such as 0D buckyballs, 1D nanotubes, and 3D graphite. Having many similarities to carbon nanotubes (CNTs) in structure and property, including its high aspect ratio (the ratio of lateral size to thickness), large surface, rich electronic states, and good mechanical properties, graphene is an attractive candidate for potential uses in many areas where the CNTs have been exploited. Superior to CNTs, the one atomic-thick graphene sheets with a 2D planar geometry will further facilitate electron transport, 16 and hence the more effective electrode materials.

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Graphenes as Potential Material for Electronics

Cited by 2,589 publications

References 201 publications

Clar’s Theory, π-Electron Distribution, and Geometry of Graphene Nanoribbons

Clar’s Theory, π-Electron Distribution, and Geometry of Graphene Nanoribbons

Tailoring Colors by O Annulation of Polycyclic Aromatic Hydrocarbons

Nitrogen-Doped Graphene as Efficient Metal-Free Electrocatalyst for Oxygen Reduction in Fuel Cells

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