Graphene

Boris Torres

MEEN 3344

Material Science

GrapheneGraphene GrapheneGraphene is a one-atom- is a one-atom-

thick planar sheet of thick planar sheet of carbon atoms that are carbon atoms that are densely packed in a densely packed in a honeycomb crystal lattice.honeycomb crystal lattice.

Graphite itself consists of Graphite itself consists of many graphene sheets many graphene sheets stacked together. stacked together.

The carbon-carbon bond The carbon-carbon bond length in graphene is length in graphene is approximately 0.142 nm.approximately 0.142 nm.

Graphene productionGraphene production Graphene sheets in solid form Graphene sheets in solid form

(e.g. density > 1g/cc) is (e.g. density > 1g/cc) is presently one of the most presently one of the most expensive materials on Earth.expensive materials on Earth.

Researchers obtained Researchers obtained relatively large graphene relatively large graphene sheets (eventually, up to 100 sheets (eventually, up to 100 micrometers in size and visible micrometers in size and visible through a magnifying glass) by through a magnifying glass) by mechanical exfoliation mechanical exfoliation (repeated peeling) of 3D (repeated peeling) of 3D graphite crystals.graphite crystals.

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

Properties of GrapheneProperties of Graphene The resistivity of the The resistivity of the

graphene sheet is 10^−6 graphene sheet is 10^−6 Ω·cm, less than the Ω·cm, less than the resistivity of silver, the resistivity of silver, the lowest resistivity lowest resistivity substance known at room substance known at room temperature. temperature.

Graphene is the strongest Graphene is the strongest substance known to man. substance known to man. Its Young's modulus is 0.5 Its Young's modulus is 0.5 TPa, which differs from TPa, which differs from bulk graphite.bulk graphite.

These intrinsic properties These intrinsic properties could lead to the possibility could lead to the possibility of utilizing Graphene for of utilizing Graphene for NEM systems applications NEM systems applications such as pressure sensors, such as pressure sensors, and resonators.and resonators.

Properties of GrapheneProperties of Graphene Engineering professors at Engineering professors at

Columbia University tested Columbia University tested graphene's strength at an graphene's strength at an atomic level by indenting a atomic level by indenting a perfect sample of the perfect sample of the material with a sharp material with a sharp probe made of diamond.probe made of diamond.

Electrons move through Electrons move through graphene with almost no graphene with almost no resistance, generating little resistance, generating little heat. What's more, heat. What's more, graphene is itself a good graphene is itself a good thermal conductor, thermal conductor, allowing heat to dissipate allowing heat to dissipate quickly.quickly.

Graphene and ApplicationsGraphene and Applications By oxidizing graphene By oxidizing graphene

flakes, and then floating flakes, and then floating them in water, the them in water, the graphene flakes form a graphene flakes form a single sheet and bond very single sheet and bond very powerfully called Graphene powerfully called Graphene oxide paper.oxide paper.

Applications:Applications: Membranes with controlled Membranes with controlled

permeabilitypermeability

Supercapacitors for energy Supercapacitors for energy applications.applications.

Graphene electronics could Graphene electronics could be useful for be useful for communications and communications and imaging technologies that imaging technologies that require ultrafast require ultrafast transistors.transistors.

ReferencesReferences Graphene http://en.wikipedia.org/wiki/Grapheneaccessed on Graphene http://en.wikipedia.org/wiki/Grapheneaccessed on

March, 29 2009March, 29 2009

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

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

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

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