Graphene is an atomic-scale honeycomb lattice made of carbon atoms. Graphene is the basic structural element ofgraphite, carbon nanotubes and fullerenes. In short ‘Graphene’ is the super thin, super strong, transparent, conductive and self-repairing material is poised to revolutionize the future by not only by super-charging batteries but also by giving flexible semiconductors and much more
Structure of graphene
Structure of graphene
Graphene is an atomic-scale honeycomb lattice made of carbon atoms. Graphene is
the basic structural element of
graphite, carbon nanotubes and fullerenes. In short ‘Graphene’ is the super thin,
super strong, transparent, conductive and self-repairing material is poised to
revolutionize the future by not only by super-charging batteries but also by giving
flexible semiconductors and much more
Graphene, fullerene, CNT and graphite
• A definition of "isolated or free-standing graphene" has
also recently been proposed: "graphene is a single atomic
plane of graphite, which—and this is essential—is
sufficiently isolated from its environment to be considered
free-standing." This definition is narrower than the
definitions given above and refers to cleaved, transferred
and suspended graphene monolayers.
• Other forms of graphene, such as graphene grown on
various metals, can also become free-standing if, for
example, suspended or transferred to silicon dioxide (SiO2).
A new example of isolated graphene is graphene on silicon
carbide (SiC) after its passivation with hydrogen.
OCCURRENCE AND PRODUCTION
• The following processes are adopted to produce
• Exfoliated graphene
• Epitaxial growth on silicon carbide
• Epitaxial growth on metal substrates
• Graphite oxide reduction
• Pyrolysis of sodium ethoxide
• From nanotubes
• From graphite by sonication
• Carbon dioxide reduction method
Due to its high electronic quality, graphene has also attracted the interest of technologists who see it as a way of
constructing ballistic transistors. Graphene exhibits a pronounced response to perpendicular external electric
fields, allowing one to build FETs (field-effect transistors). In their 2004 paper, the Manchester group
demonstrated FETs with a "rather modest" on-off ratio of ~30 at room temperature. In 2006, Georgia
Tech researchers, led by Walter de Heer, announced that they had successfully built an all-graphene planar FET
with side gates. Their devices showed changes of 2% at cryogenic temperatures. The first top-gated FET (on-off
ratio of <2) was demonstrated by researchers of AMICA and RWTH Aachen University in 2007.Graphene
nanoribbons may prove generally capable of replacing silicon as a semiconductor in modern technology.
Facing the fact that current graphene transistors show a very poor on-off ratio, researchers are trying to find ways
for improvement. In 2008, researchers of AMICA and University of Manchester demonstrated a new switching
effect in graphene field-effect devices. This switching effect is based on a reversible chemical modification of the
graphene layer and gives an on-off ratio of greater than six orders of magnitude. These reversible switches could
potentially be applied to non-volatile memories.
Graphene has the ideal properties to be an excellent component of integrated circuits.
Graphene has a high carrier mobility, as well as low noise, allowing it to be used as the channel
in a field-effect transistor. The issue is that single sheets of graphene are hard to produce, and
even harder to make on top of an appropriate substrate. Researchers are looking into methods
of transferring single graphene sheets from their source of origin (mechanical exfoliation on
SiO2 / Si or thermal graphitization of a SiC surface) onto a target substrate of interest. In 2008,
the smallest transistor so far, one atom thick, 10 atoms wide was made of graphene. IBM
announced in December 2008 that they fabricated and characterized graphene transistors
operating at GHz frequencies. In May 2009, an n-type transistor was announced meaning that
both n and p-type transistors have now been created with graphene functional graphene
integrated circuit was also demonstrated – a complementary inverter consisting of one p- and
one n-type graphene transistor. However, this inverter also suffered from a very low voltage
The Intel LIGHTPEAK uses graphene technology.
Graphene-based nanotechnology in
Graphene-based nonmaterials have many promising applications in energyrelated areas. Just some recent examples: Graphene improves both energy
capacity and charge rate in rechargeable batteries; activated graphene makes
superior supercapacitors for energy storage; graphene electrodes may lead to a
promising approach for making solar cells that are inexpensive, lightweight and
flexible; and multifunctional graphene mats are promising substrates for
Schematic models of chemical strategies towards graphene from different carbon
The most unique aspect of the OPV cell devise is the transparent conductive electrode. This allows the
light to react with the active materials inside and create the electricity. Now graphene/polymer sheets
are used to create thick arrays of flexible OPV cells and they are used to convert solar radiation into
electricity providing cheap power. A research team under the guidance of Chongwu Zhou, Professor of
Electrical Engineering, USC Viterbi School of Engineering has put forward the theory that the graphene
– in its form as atom-thick carbon atom sheets and then attached to very flexible polymer sheets with
thermo-plastic layer protection will be incorporated into the OPV cells. By chemical vapour deposition,
quality graphene can now be produced in sufficient quantities also. The traditional silicon solar cells
are more efficient as 14 watts of power will be generated from 1000 watts of sunlight where as only
1.3 watts of power can be generated from a graphene OPV cell. But these OPV cells more than
compensate by having more advantages like physical flexibility and costing less
The flexibility of OPVs gives these cells additional advantage by being operational after repeated bending
unlike the Indium-Tin-Oxide cells. Low cost, conductivity, stability, electrode/organic film compatibility, and
easy availability along with flexibility give graphene OPV cell a decidedly added advantage over other solar
A graphene solar cell, its structure and
a graphene Organic LED.
• The energy densities and performances of rechargeable
lithium ion batteries – which are used widely in portable
electronics such as cell phones, laptop computers, digital
cameras, etc. – largely depend on the physical and chemical
properties of the electrode materials. Thus, many research
attempts have been made to design novel nanostructures
and to explore new electrode materials in order to achieve
higher capacity and to increase the battery's charge rate,
increasingly also employing graphene in form of
nanosheets, paper, and carbon nanotube or fullerene
hybrids (for a detailed review see here: "Graphene-based
electrode materials for rechargeable lithium batteries").
Antibacterial Paper Made From Graphene
Scientists at Shanghai Institute of Applied Physics have shown that graphene, a
material which is a sheet of carbon exactly one atom thick, does not allow the
growth of bacteria on its surface. This is in contrast to mammalian cells which
seem to do just fine when in contact with the graphene. It has been found that
sheets of graphene oxide are highly effective at killing bacteria such as Escherichia
coli. This means graphene could be useful in applications such as hygiene products
or packaging that will help keep food fresh for longer periods of time.
We find that graphene derivatives – graphene oxide, graphene oxide and
reduced graphene oxide – can effectively inhibit bacterial growth" Chunhai
Fan, a professor in the Laboratory of Physical Biology at the Shanghai Institute
of Applied Physics. "This is a significant finding as both previous and our own
studies have proven that graphene, particularly graphene oxide, is
biocompatible and cells can grow well on graphene substrates. Furthermore,
while silver and silver nanoparticles have been well known to be antibacterial,
they and other nanomaterials are often cytotoxic.
A sheet of graphene paper and Schematic illustration of E.coli exposed
to graphene nanosheets. (Image: Dr. Fan, Shanghai Institute of Applied
Graphene As An Anti Corrosive Coating
New research has established the "miracle material" called graphene as the world's
thinnest known coating for protecting metals against corrosion. Corrosion results from
contact of the metal's surface with air, water or other substances. One major
approach involves coating metals with materials that shield the metal surface, but
currently used materials have limitations. The scientists decided to evaluate graphene
as a new coating. Graphene is a single layer of carbon atoms, many layers of which are
in lead pencils and charcoal, and is the thinnest, strongest known material. That's why
it is called the miracle material. In graphene, the carbon atoms are arranged like a
chicken-wire fence in a layer so thin that is transparent, and an ounce would cover 28
Researchers found that graphene, whether made directly on copper or nickel or
transferred onto another metal, provide protection against corrosion. Copper
coated by growing a single layer of graphene through chemical vapor deposition
(CVD) corroded seven times slower than bare copper, and nickel coated by
growing multiple layers of graphene corroded 20 times slower than bare nickel
• Researchers from Monash University and Rice University developed a thin
graphene film anti-corrosion coating. Their new coating can maker copper
more resistant to corrosion - almost 100 times better than uncoated copper.
According to the researchers, that's the best graphene-based anti-corrosion
material developed yet.
The researchers are optimistic that the new coating will be an effective replacement
for hexavalent chromium corrosion-prevention coatings, which have been linked to
cancer-causing pollution. Banerjee’s work is supported by Tata Steel and the New York
State Pollution Prevention Institute (a partnership among Rochester Institute of
Technology, Clarkson University, Rensselaer Polytechnic Institute, University at Buffalo
and the 10 NYS Regional Technology Development Centers). UB has filed an
application for a provisional patent on the coatings.
Researchers from the Shenyang National Laboratory for Materials Science and the
Rensselaer Polytechnic Institute have shown that graphene can be used to create a
superhydrophobic coating material that shows stable superhydrophobicity under both
static as well as dynamic (droplet impact) conditions
Graphene's modifiable chemistry, large surface area, atomic thickness and
molecularly-gatable structure make antibody-functionalized graphene sheets
excellent candidates for mammalian and microbial detection and diagnosis
The most ambitious biological application of graphene is for rapid, inexpensive
electronic DNA sequencing. Integration of graphene (thickness of 0.34 nm)
layers as nanoelectrodes into a nanopore can solve one of the bottleneck
issues of nanopore-based single-molecule DNA sequencing.
The researchers grew graphene over a nickel foam template which was then
leeched away. The remaining graphene foam (layered graphene sheets) was
coated with a Teflon layer. They say that the pore size and structure of the
graphene foam can be uniformly tuned by selecting the appropriate nickel
Now the question arises why we have chosen only “GRAPHENE” for this study and not any
The answer to this question is quite simple. First of all Graphene is the material of the present
time and it holds the key to a very eventful and bright future of our human race. With so much
to offer graphene has already proven to be worthy of being called ‘The Magic Material’. Today
no other material is so diverse i.e. no other material has important applications as graphene.
Some of its present applications have been already discussed above. But that’s not all graphene
has to offer. In addition to the above graphene is being used in top notch researches that are
potent enough to entirely change our future.
The qualities that sets apart graphene from other smart and industrial material are:
It is cost effective. And once synthesized for a particular application its cost effectiveness
Graphene, as like other smart materials has unique properties; in combination of other
materials graphene has proven to be very useful.
There are other materials but they can’t provide flexibility to work with them as graphene
does. Since it is just a layer, it can be molded and formed in whatever shape and form desired.
The current applications are very vital like alternative energy source, desalination, high speed
The scope of application of this material is very wide.
And still scientists and researchers are looking for its new aspects and are at verge of making
• As scientists battle to bend graphene to their will in
the high-profile realm of electronic components,
researchers working on more straightforward
applications of this two-dimensional, atom-thin
sheet of carbon are also making some interesting
discoveries. Some of the important applications of
graphene have been touched in this paper; but the
scope of graphene is very vast and the above should
not be mistaken for what this material has to offer.
The applications of graphene are numerous and in
future we can expect a lot from “GRAPHENE”.