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technospice presents

GRAPHENE

PRESANTATORS

K.RAHUL SANKRUT

JAYA SREEKAR

ANIRUDH

SRIKAR

SRIKANTH

M.SANTOSH

MAHINDER

BRIEF HISTORY PROPERTIES

POTENTIAL APPLICATIONS MAJESTIC FUTURE

INTRESTINTG FACTS

Andre Geim and Konstantin

Novoselov have shown that carbon in

such a flat form has exceptional

properties.

Konstantin Novoselow and Andre Geim were awarded the 2010 Nobel Prize

This at a time when many believed it was impossible for such thin crystalline materials to be stable.

Graphene literally changes our lives in the 21st century

Graphene is the thinnest possible material that is even feasible

It conducts electricity better than any material known to man—at room temperature.

Interesting facts about graphene

Carbon, the basis of all known life on earth, has surprised us once again.

Graphene is a form of carbon.

As a conductor of heat it outperforms all other known materials.

Its is the best conductor of electricity ever known

It is a strong material

It is almost completely transparent

It’s 97.3 percent

transparent, but

looks really cool

under powerful

microscopes

Physicists can now study a

new class of two-dimensional

materials with unique

properties.

Graphene makes experiments possible that give new twists to the phenomena in quantum physics.

Creation of new materials and the manufacture of innovative electronics

Graphene transistors are predicted to be substantially faster than today’s silicon transistors

The theory behind the substance graphene was first explored by theoretical physicist Philip Wallace in 1947.

The name graphene wasn't actually coined 40 years later

Graphene in itself however wasn't discovered until 2004 in its full observable and testable form

BRIEF HISTORY

Since then, in the past 6 years, scientists have discovered that the substance retains some amazing properties.

The term graphene first appeared in 1987

Single layers of graphite were previously (starting from the 1970s) grown epitaxially on top of other materials.

There have also been a number of efforts to make very thin films of graphite by mechanical exfoliation

A key advance in the science of graphene was brought by  Andre Geim and Konstantin Novoselov at Manchester University 

Scotch tape technique

PROPERTIESAtomic structureThe atomic structure of isolated, single-layer graphene was studied by transmission electron microscopy (TEM)

Hexagonal lattice

Suspended graphene also showed "rippling" of the flat sheet, with amplitude of about one nanometer.

Electronic properties

Graphene differs from most conventional three-dimensional materials..Intrinsic graphene is a semi-metal or zero-gap semiconductor

Graphene has a remarkably high electron mobility at room temperature 15,000 cm2V−1s−1

The mobility is nearly independent of temperature between 10 K and 100 K

 Resistivity of the graphene sheet would be 10−6 Ω·cm.

Optical properties

Unexpectedly high opacity for an atomic monolayerit

absorbs πα ≈ 2.3% of white lightThis is "a consequence of the unusual low-energy electronic structure of monolayer graphene

It is further confirmed that such unique absorption could become saturated when the input optical intensity is above a threshold value

saturable absorption

saturation fluency

 Due to this special property, graphene

has wide application in ultrafast photonics

Thermal propertiesThe near-room temperature thermal conductivity of graphene was recently measured to be between (4.84±0.44) ×103 to (5.30±0.48) ×103 Wm−1K−1.

Mechanical properties

As of 2009, graphene appears to be one of the strongest materials ever tested.

Bulk strength is 130GPa 200 times greater than steel

Graphene sheets, held together by van der Waals forces

peeling off layers of graphite with a sticky tape

Mechanical cleavage

optical microscope image ofresulting flakes

Dimensionality of carbon

diamond, graphite

GRAPHENErealized in 2004

carbon nanotubes

fullerenes, buckyballs

It's essentially the basic building block for graphitic materials of all other dimensionalities; it's a stepping stone to building bigger things

Graphene biodevices

Anti-bacterial

POTENTIAL APPLICATIONS OF GRAPHENESingle molecule gas detection

Graphene nanoribbons

Graphene transistors

Integrated circuits

Transparent conducting electrodes

Solar cells

Nanogaps in graphene sheets may potentially provide a new technique for rapid DNA sequencing.

Graphene-based sensors could sniff out dangerous molecules

Escherichia coli

It is practically transparent and a good conductor

When mixed into plastics, graphene can turn them into conductors of electricity

MAJESTIC FUTUREAdvancements in touch screens

Stiffer-stronger-lighter plastics

In the future, satellites, airplanes, and cars could be manufactured out of the new composite materials.

The fastest growing problem facing chip engineers today can be solved

Embedding the material in plastics to enable them to conduct electricity

Increasing the efficiency of electric batteries by use of graphene powderOptoelectronics

Leak-tight, plastic containers that keep food fresh for weeks

Transparent conductive coatings for solar cells and displays

Stronger wind turbines

Stronger medical implants

Better sports equipment

Super capacitorsImproved conductivity of materials;

High-power high frequency electronic devices Artificial membranes for separating two liquid reservoirs

Replacing silicon in transistors

LCD's

Graphene nanoribbons could be a way to construct ballistic transistors

Organic light-emitting diodes(OLEDs)