The 2-D material That Can Change Everything

Presented By: Zaahir SalamM.TECH NST .

The Nobel Prize in Physics for 2010 was awarded to Andre Geim and Konstantin Novoselov at the University of Manchester.

Andre Geim Konstantin Novoselov

Graphene can be synthesized from Graphite tocreate the thinnest, strongest and most conductivematerial know today.

Graphite flakes are actually made of many layersof graphene stacked on top of each other withweak bonds holding them together.

INTRODUCTION

2-dimensional hexagonal lattice of carbon

sp2 hybridized carbon atoms

Among strongest bonds in nature

Electrons in p-orbitalsabove and below plane.

p-orbitals become conjugated across the plane.

Electrons free to move across plane in delocalized orbitals.

Extremely high tensile strength.

http://en.wikipedia.org/wiki/Aromaticity

0D buckyballs 1D nanotubes 3D graphite.

Mother of all graphitic forms

A. K. Geim & K. S. Novoselov. The rise of graphene. Nature Materials Vol 6 183-191 (March 2007)

AFM Image TEM Image SEM Image

Graphene Visualized Under Various Available Microscopes

A. K. Geim & K. S. Novoselov. The rise of graphene. Nature Materials Vol 6 183-191 (March 2007)

Graphene production Graphene sheets in solid form (e.g.

density > 1g/cc) is presently one ofthe most expensive materials onEarth.

Researchers obtained relativelylarge graphene sheets (eventually,up to 100 micrometers in size andvisible through a magnifying glass)by mechanical exfoliation (repeatedpeeling) of 3D graphite crystals.

Another method is to heat siliconcarbide to high temperatures(1100°C) to reduce it to graphene.

Graphene can be isolated in 1 atom thick sheets of

carbon atoms arranged in honey comb Structure.

Length Of a Hexagon side is 0.142 nanometers.

3 million sheets of graphene stacked on one

another are 1 millimeter thick..

Graphene Unique properties

STRENGTH:

It is 200 X more STRONGER than Structural Steel.

Its Young's modulus is 0.5 TPa

CONDUCTIVE:

The resistivity of the graphene sheet is 10−6 Ω·cm, less than theresistivity of silver, the lowest resistivity substance known at roomtemperature.

It can Conduct 1000 X density of current in copper.

Conducts 10 X heat better than Copper.

FLEXIBLE: Can Flex 20% without damage.

2-D IN STRUCTURE:

Each layer is 1 atom thick which gives unique electrical and computing properties.

TRANSPARENT: Its 97.3 % Transparent.

Potential Applications: Graphene is being currently being tested by

researchers and the following applications areconsidered:

COMPUTING: Graphene may be able to replace semiconductor in

computer chips and electronics.

No need of cooling fans as it functions at roomtemperature.

MIT has developed at 1000+ GHZ graphenemicrochip that is 300 times faster thancommercially available chips today.

This all could mean smaller and morepowerful chips.

CHALLENGE :

The Graphene transistors cannot be switchedon to off. This is a challenge researchers arecurrently taking ON.

Materials: Graphene can be added in small

amounts to metal and plastics to makestronger and lighter compositematerials.

Vehicles and airplanes could be lighterand stronger, increasing fuel efficiencyand safety.

By seeding plastics with just 1%Graphene they can become conductivewhile remaining transparent.

Energy + Optics

Graphene Could replace indium tomake better solar cells which areflexible, cheaper and suited for massproduction.

Graphene could make bettertouchscreens, LCD’s and LED’s.

Graphene may revolutionize datatransfer it can make smaller opticalmodulators that transfer data atspeeds upto 10X faster than currenttechnology.

References Graphene http://en.wikipedia.org/wiki/Grapheneaccessed

on March, 29 2009

Graphene Confirmed the World’s Stronged Known Material http://gizmodo.com/5026404/graphene-confirmed-as-the-worlds-strongest-known-material accessed on March, 29 2009

Nanotechnology Reserchers go Ballistic Over Graphenehttp://www.nanowerk.com/spotlight/spotid=2340.php accessed on March 29, 2009

TR10: Graphene Transistorshttp://www.technologyreview.com/read_article.aspx?ch=specialsections&sc=emerging08&id=20242 accessed on March 29, 2009

Graphene: Charged Up http://www.natureasia.com/asia-materials/highlight.php?id=77 accessed on March 29, 2009

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