What is Graphene: Definition and 211 Discussions

Graphene () is an allotrope of carbon consisting of a single layer of atoms arranged in a two-dimensional honeycomb lattice. The name is a portmanteau of "graphite" and the suffix -ene, reflecting the fact that the graphite allotrope of carbon consists of stacked graphene layers.Each atom in a graphene sheet is connected to its three nearest neighbors by a σ-bond, and contributes one electron to a conduction band that extends over the whole sheet. This is the same type of bonding seen in carbon nanotubes and polycyclic aromatic hydrocarbons, and (partially) in fullerenes and glassy carbon. These conduction bands make graphene a semimetal with unusual electronic properties that are best described by theories for massless relativistic particles. Charge carriers in graphene show linear, rather than quadratic, dependence of energy on momentum, and field-effect transistors with graphene can be made that show bipolar conduction. Charge transport is ballistic over long distances; the material exhibits large quantum oscillations and large and nonlinear diamagnetism. Graphene conducts heat and electricity very efficiently along its plane. The material strongly absorbs light of all visible wavelengths, which accounts for the black color of graphite; yet a single graphene sheet is nearly transparent because of its extreme thinness. The material is also about 100 times stronger than would be the strongest steel of the same thickness.

Scientists theorized the potential existence and production of graphene for decades. It has likely been unknowingly produced in small quantities for centuries, through the use of pencils and other similar applications of graphite. It was originally observed in electron microscopes in 1962, but only studied while supported on metal surfaces. The material was later rediscovered, isolated and characterized in 2004 by Andre Geim and Konstantin Novoselov at the University of Manchester, who were awarded the Nobel Prize in Physics in 2010 for their research on the material. High-quality graphene proved to be surprisingly easy to isolate.
The global market for graphene was $9 million in 2012, with most of the demand from research and development in semiconductor, electronics, electric batteries, and composites.
The IUPAC (International Union for Pure and Applied Chemistry) recommends use of the name "graphite" for the three-dimensional material, and "graphene" only when the reactions, structural relations or other properties of individual layers are discussed. A narrower definition, of "isolated or free-standing graphene" requires that the layer be sufficiently isolated from its environment, but would include layers suspended or transferred to silicon dioxide or silicon carbide.

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  1. I

    Calculate Electrical Pressure Capacity with Graphene Work Function

    Is the reciprocal of the work function of ' Graphene ' a usable tool for the calculation of the electrical pressure * capacity or even an indicator of co-conductivity of a given area of (magnetically oriented) Graphene in relation to a substrate material which is also conductive ?
  2. A

    Congratulations Mechanical Engineers

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  3. Kevin McHugh

    MIT Develops Compressed Graphene Sponge with Endless Uses

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  4. C

    I Graphene Substrate: Can it Maintain 2D Form?

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  5. R

    I Can Carbon in the Air Be Transformed into Graphene?

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  6. Dragul

    Will we live in and wear graphene in the near future?

    From what I'm hearing, graphene will change the way we live, work and play. Everything from cars and clothing to workplaces and weaponry will incorporate the stuff. Is this true, the hype of stock promoters or something in between? Which aspects of life will be the most affected by the use of...
  7. A

    A Zigzag Graphene Nanoribbons: Metallicity Explained

    Hi. Why Zigzag graphene nanoribbons is metallics??
  8. billy k

    How to Make Graphene: Tips for Taking it a Step Further

    Hi i saw some technics with sticky tape and pencils(i know its not pure graphite) but how can i take it a step further to produce more ?
  9. A

    A Insert Strain on Graphene with Tight Binding Methods

    How to insert strain on graphene using tight binding methods? How strain can be applied in one of the x or y axis?
  10. N

    A Is Graphene a Two-Dimensional Weyl Semimetal with Spin Degenerate Dirac Bands?

    I'm recently interested in the topological/Weyl semimetals, but I'm not an expert on the theory. Most papers just define Weyl semimetal as a material that have pairs of Weyl points with opposite Berry curvature. Here in graphene, the Berry curvature of the Dirac cones at K and K' point is also...
  11. S

    A Wavefunction matching two different H, not just V

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  12. B

    A Young's modulus graphene nanoribbons

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  13. A

    A Mechanical properties graphene nanoribbons

    Hi In calculation the mechanical properties of graphene nanoribbons by tight binding methods should band structure graphene calculated by the DFT and tight binding methods fitted to calculate b parameter. In the tight binding methods hopping parameter changes as follow: t'_{ppsigma}=t_{ppsigma}...
  14. M

    A Can Doping Concentration Affect the Band Gap in Graphene?

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  15. Harry Smith

    I Will ethanol destroy double layered graphene?

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  16. A

    Make Graphene Suit: Stacking Layers for Flexibility & Strength

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  17. Q

    A STM images of graphene, graphite and Silicon carbide

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  18. thund3rcz

    I Effect of SAM physisorbed on graphene - some questions

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  19. A

    Tight binding for graphene pz orbital

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  20. T

    Graphene: Questions from a Non-Chemist

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  21. M

    A Electrostatic Repulsion of graphene layer on metal surface

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  22. E

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  23. C

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  24. A

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  25. A

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  26. M

    CASTEP simulation for graphene band structure

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  27. Aaron young

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  28. J

    What is the best laser for replicating this experiment?

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  29. T

    Book recommendation on fundamental physics in Graphene

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  30. M

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  31. H

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  32. B

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  33. D

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  34. G

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  35. B

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  36. Benevito

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  37. N

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  38. Surender Pratap

    How we can add magnetic field term in graphene nanoribbon Hamiltonian

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  39. B

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  40. atyy

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  41. P

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  42. S

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  43. F

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  44. D

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  45. I

    Compute subband structure of graphene

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  46. S

    Graphene Allows Protons to Pass Through

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  47. R

    Graphene Nobel winners discover new property of graphene

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  48. M

    Graphene Conductivity: Testing the Resistance

    Hi I've made what I think is graphene. I first put the solution on cardboard and then I put some on polyethylene. When they had dried, I tested conductivity with a digital multimeter with the scale set on megaohms. The cardboard was nonconducting, but the sample on poly to my astonishment showed...
  49. G

    Exploring the Potential of Graphene: A Futurist's Perspective

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  50. S

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