The 2-D material That Can Change Everything Presented By: Zaahir Salam M.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
INTRODUCTIONGraphene can be synthesized from Graphite to create the thinnest, strongest and most conductive material know today.Graphite flakes are actually made of many layers of graphene stacked on top of each other with weak bonds holding them together.
2-dimensional Electrons in p-orbitals hexagonal lattice of above and below plane. carbon p-orbitals become conjugated across the plane. Electrons free to move across plane in delocalized orbitals. sp2 hybridized carbon atoms Extremely high tensile strength. Among strongest bonds in nature http://en.wikipedia.org/wiki/Aromaticity
Mother of all graphitic forms0D buckyballs 1D nanotubes 3D graphite. A. K. Geim & K. S. Novoselov. The rise of graphene. Nature Materials Vol 6 183-191 (March 2007)
Graphene Visualized Under Various Available MicroscopesAFM Image TEM Image SEM Image 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 of the most expensive materials on Earth. Researchers obtained relatively large graphene sheets (eventually, up to 100 micrometers in size and visible through a magnifying glass) by mechanical exfoliation (repeated peeling) of 3D graphite crystals. Another method is to heat silicon carbide 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 Youngs modulus is 0.5 TPa CONDUCTIVE: The resistivity of the graphene sheet is 10−6 Ω·cm, less than the resistivity of silver, the lowest resistivity substance known at room temperature. 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 are considered: COMPUTING: Graphene may be able to replace semiconductor in computer chips and electronics. No need of cooling fans as it functions at room temperature.
MIT has developed at 1000+ GHZ graphene microchip that is 300 times faster than commercially available chips today. This all could mean smaller and more powerful chips. CHALLENGE : The Graphene transistors cannot be switched on to off. This is a challenge researchers are currently taking ON.
Materials: Graphene can be added in small amounts to metal and plastics to make stronger and lighter composite materials. Vehicles and airplanes could be lighter and stronger, increasing fuel efficiency and safety. By seeding plastics with just 1% Graphene they can become conductive while remaining transparent.
Energy + Optics Graphene Could replace indium to make better solar cells which are flexible, cheaper and suited for mass production. Graphene could make better touchscreens, LCD’s and LED’s. Graphene may revolutionize data transfer it can make smaller optical modulators that transfer data at speeds upto 10X faster than current technology.
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 Graphene http://www.nanowerk.com/spotlight/spotid=2340.php accessed on March 29, 2009 TR10: Graphene Transistors http://www.technologyreview.com/read_article.aspx?ch=specialse ctions&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