Graphene

19

Transcript of Graphene

Page 1: Graphene
Page 2: Graphene

• Graphene is an allotrope of Carbon (Like Diamond) but arranged in a very thin (one atom thick) planar sheet of bonded carbon atoms densely packed in a honeycomb lattice structure.

Page 3: Graphene

• A great way of thinking about Graphene is to start with a standard pencil and draw a line on a piece of paper.  Most pencils are made using Graphite for their core and nearly every one of us has drawn a line on paper with a pencil. Therefore, we have all experienced and ‘made’ an extremely thin layer of Graphite on the paper – and a single layer of one-Atom thick Graphite sheet is in fact Graphene.

Page 4: Graphene

• Scientists had previously discovered single-layered carbon structures, such as rolled up sheets of carbon known as nanotubes and hollow balls of carbon commonly called fullerenes or buckyballs. But few believed that single sheets of carbon could be produced; They were thought to be too unstable.

• That's where ANDRE GEIM and KONSTANTIN NOVOSELOV came in. They took a hunk of graphite and used Scotch tape to peel off layer after layer after layer. Geim and Novoselov then analyzed what they had left, and found graphene. For their discovery – which was published in 2004 – they were awarded the 2010 Nobel Prize in Physics.

Page 5: Graphene

• Graphene is the thinnest material possible. Its thickness does not exceed that of an individual carbon atom, and for all intents and purposes can be considered two-dimensional. Graphene is thus very flexible and can be reshaped and folded into tubes according to compatibility, thus reducing the size and portability.

• As it does not have any band gap so it has high electrical and thermal conductivity. This property makes it a very good material to be used in batteries and touch screens and is essential to the development of the next generation of computing.

Page 6: Graphene

• Because graphene is only one atom thick, pure graphene is transparent. This property could lead to graphene being used to create transparent electrodes for light-based applications such as LED's or vastly improved solar cells.

Page 7: Graphene

• Besides being the thinnest possiblematerial, graphene is also one of the strongest at more than 200 times the strength of steel. Researchers at Columbia University's Foundation School of Engineering said recently that "It would take an elephant, balanced on a pencil, to break through a sheet of

• graphene”.

Page 8: Graphene

ULTRACAPACITORS:• Today's batteries are increasingly an issue. They constantly need to be recharged, hold comparatively small amounts of energy, and deteriorate quickly. Graphene may provide an alternative in the form of ultra capacitors.

•Graphene based ultra capacitors could store more energy, more efficiently than current batteries. Additionally, ultra capacitors have a longer life, are lighter, more flexible, and are easier to maintain. Imagine not having to recharge your computer for days, or your cell phone for months, all while never having them get too hot, or having to replace the battery!

Page 9: Graphene

SOLAR CELLS: Thin films of graphene could provide a cheap replacement of the conventional photovoltaic and could produce excellent Solar Cells due to its high electrical and thermal conductivity, including no band gap.

Page 10: Graphene

NEXT-GENERATION DISPLAYS: Researchers at Stanford University have successfully developed a brand new concept of flexible organic lighting-emitting diodes (FOLEDs) with a few nanometer of graphene as transparent conductor. This could pave the way for inexpensive mass production of FOLEDs on large-area low cost flexible plastic substrate, which could be rolled up like wallpaper and applied virtually anywhere.

Page 11: Graphene

Lower cost of display screens in mobile devices :

Researchers have found that graphene can replace indium-based electrodes in flexible organic light emitting diodes (FOLED). These diodes are used in electronic device display screens which require low power consumption. The use of graphene instead of indium not only reduces the cost but eliminates the use of metals in the FOLED, which may make devices easier to recycle.

Page 12: Graphene

Foldable flat screens and unbreakable mobiles

•Graphene is also flexible having high tensile strength, which paves the way for foldable flat screens and mobile cell phones that can be dropped without their screens breaking.

Lithium-ion Batteries That Recharge Faster: •These batteries use graphene on the surface of the anode surface. Defects in the graphene sheet (introduced using a heat treatment) provide pathways for the lithium ions to attach to the anode substrate. Studies have shown that the time needed to recharge a battery using the graphene anode is much shorter than with conventional lithium-ion batteries, thus increasing the life of the battery also.

Page 13: Graphene

Graphene flat screens a year from now?

Soon the super-thin material will part company with the white lab coats and flasks to join you in front of your sofa in the shape of even thinner and faster-reacting flat screens replacing conventional LCD’s and LED’s.

Page 14: Graphene

• Although only seven years have passed since scientists became able to produce and examine graphene in free form, research has already come so far that the first screens made from graphene could be ready to go into mass production.

• "It may not be very long until we will be using transparent electrodes made of graphene in commercial products. Graphene might be used in flat screens a year from now”.

Page 15: Graphene

A Step towards the future…

• Mobile Companies like Samsung and Nokia have taken up the graphene technology and decided to blend it with the smart phones bringing out a wide difference in its look and features.

Page 16: Graphene

• The next generation Smartphones will have flexible touch screens, resizable and foldable body, large battery backup with a longer life, auto charging capacity and great looks which would definitely leave the gizmo enthusiasts spellbound and rock the mobile space with the extraordinary features.

Page 17: Graphene

Conclusion• Though graphene has not touched our

commercial lives yet, it has great potential and will eventually come around to us. Besides that’s how most great inventions and scientific advancements work, they are discovered followed by a large stretch of time when nobody finds a use, followed by a significant invention. Rest assured, whether or not graphene replaces silicon as the material of the generation, it will still help engineers greatly advance technology and is a worthwhile discovery.

Page 18: Graphene

References• http://www.iupac.org/ • http://www.graphene.manchester.ac.uk/ • http://onnes.ph.man.ac.uk/nano/

Publications/Naturemat_2007Review.pdf • http://www.nsf.gov/news/news_summ.jsp?

cntn_id=111341&org=NSF&from=news• http://www.google.com/• http://www.youtube.com/

Page 19: Graphene