# Graphene Definition and 136 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.
35. ### What's a general algorithm to build a supercell from a primitive cell?

Basically, I've written some code that take as inputs 1)Basis vectors 2)lattice translation vectors and computes the structure factor of the basis, producing a diffraction pattern. I'd like to begin incorporating subtle differences between atoms, so I want to compute the structure factor of...
36. ### In order to generate electricity is copper required?

Copper conducts electricity and so does other metals like silver. Now a new material is coming to play which is graphene, But I was wondering in order to generate electricity must it be in copper coils? Can it be in silver coils, graphene coils? ^.^
37. ### Quastion about K-points and energy cutoff

Dear All, I have three questions about the relation between the K-points and energy cutoff. The first one is : how many k points should I use in my theoretical calculation to get a good result in lattice constant and the converge of Emin especially for using DFT? The second one is : What is...
38. ### Electric Car Advances

A lot of people have been arguing that TSLA's stock/the company in general wont take off because the demand is above the battery technology at this time. I'm a junior in college studying physics but will probably either switch to finance and do stocks because i like it more or i was double major...
39. ### Post-B.S. Struggles

I'll just launch into it: I graduated recently from Temple University with a B.S in Physics, GPA 3.83. I worked in three labs, one semester each, during my studies: one for pay, one volunteer, and one for credit. In the first, I did analysis for Mossbauer spectroscopy; in the second, I produced...
40. ### Density of states

Homework Statement Using the dispersion relation at the Dirac Point calculate the electron density of states for graphene in both the valence and conduction band. Homework Equations ρ = density of states = k2/pi2 The Attempt at a Solution I looked up what Dirac Points...
41. ### Right Qualifications for DFT in Industry

Hi All, I'm finishing up my PhD in Computational Condensed Matter. I've worked almost exclusively in spin systems using things like Monte Carlo and Exact Diagonalization. However, my specialty is in producing high-quality, high-performance, often parallel research codes (i.e. none of my...
42. ### Night vision based on OLED technology

Hello, I started this topic to discuss interesting new night vision technology that was presented on TED talks. Old, expensive and bulky IR (or other light spectrum) IIT amplifier could be replaced with very thin OLED based, cheaper and low power consuming image intensifier which was developed...
43. ### Derivation of Height Function given an angle

Hey everyone, I'm currently doing research at a University, I've been working on a problem for a few hours and wrote up a quick paper that shows my derivation of a certain height based on an angle. Basically the experiment is looking at optical properties of graphene, but for this to happen we...
44. ### Possible application of Genetic Algorithms

Ok so I have a view ideas in mind for a project I was planning on doing involving genetic algorithms for my high school science fair class. I do have 3 mentors one a mathematician, a computer scientist who focuses on GAs, and a physicist who focuses on nano structures. here where I live, but...
45. ### Standardized Elephant

Recently, reading an article about graphene, it was disclosed that a sheet of graphene the thickness of a piece of plastic wrap could support the weight of an elephant balanced on a pencil. Beyond the fact that I highly doubt anyone got an elephant (although good at balancing tricks I have seen...
46. ### How do you specify your intererests in physics when you're a freshman

Hello, I'm interested in research and development of either fusion power generation or graphene based nanoelectronics. One of the things I like about these areas is that they are in the imminent stages of development and I will probably see them developed in my lifetime. My issue is that...
47. ### Carbon nanotube exoskeleton

Can we make exoskeletons out of CNTs? I have a few questions 1. Do CNTs expand when electricity is applied or you have to put wax betwen them? 2. Can we produce enough nanotubes to make a full-body suit? 3. Is graphene suitable for an armor? Some say that when you put a elephant on a...
48. ### Career in Simulations

I've gotten really interested in CFD and DFT recently. I have a BS in Chemical Engineering and will be 25 in about a month. Been working in the oil industry for the last 2 years and before that I worked in a carbon nanotube and graphene 'factory' for lack of a better term that I can come up with...
49. ### Help with the Tight Binding model

Hi everyone, I'm trying to fit the Tight Binding molecule for a more complicated system, so I'm first trying to understand it for a simpler one, graphene. I've read several guides but they're all confusing me. Right now, I'm trying to understand the graphene example on this site. My biggest...
50. ### The theoretical Augmentations

The theoretical "Augmentations" One thing that is somewhat common and has to do with medical science and my interests are augmentations, robotic, nano-technological, or even sometimes genetic enhancements. In the science fiction representations people can outperform human strength and speed...