It has likely been unknowingly produced in small quantities for centuries, through the use of pencils and other similar applications of graphite. Scientists theorized the potential existence and production of graphene for decades. This one-atom-thick material can be seen with the naked eye because it absorbs approximately 2.3% of light. Photograph of a suspended graphene membrane in transmitted light. The material is about 100 times as strong as would be the strongest steel of the same thickness. 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. Graphene conducts heat and electricity very efficiently along its plane. Charge transport is ballistic over long distances the material exhibits large quantum oscillations and large and nonlinear diamagnetism. 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. The valence band is touched by a conduction band, making graphene a semimetal with unusual electronic properties that are best described by theories for massless relativistic particles. This is the same type of bonding seen in carbon nanotubes and polycyclic aromatic hydrocarbons, and (partially) in fullerenes and glassy carbon. The name is derived from "graphite" and the suffix -ene, reflecting the fact that the graphite allotrope of carbon contains numerous double bonds.Įach atom in a graphene sheet is connected to its three nearest neighbors by σ-bonds and a delocalised π-bond, which contributes to a valence band that extends over the whole sheet.
Graphene ( / ˈ ɡ r æ f iː n/ ) is an allotrope of carbon consisting of a single layer of atoms arranged in a hexagonal lattice nanostructure. Graphene is an atomic-scale hexagonal lattice made of carbon atoms.
0 kommentar(er)
