2. What Is Graphene??
• Graphene, which is a single layer of carbon atoms assembled in a honeycomb lattice and has
extraordinary electronic properties. In fact, its has amazing photonic properties. Graphene interacts
with light strongly from ultraviolet to far infrared, and such interaction is tunable by electric field.
Moreover graphene is gapless and tunable bandgap can be created by breaking its intrinsic
crystallographic symmetry. These unique properties make graphene a promising candidate for
various light detection, manipulation, and generation applications in an ultra-wide operational
wavelength range.
• Fig(a) describes the Dirac point between two layers of graphene and fig(b) shows the multilayer of
graphene.
3. Structure of Graphene.
• Graphene can be described as a 2D one- atom thick layer of graphite.
• Graphene is the strongest, thinnest material known to exist.
• It is almost completely transparent, yet so dense that not even helium can pass through it.
• It is one of the strong metal, it is 200 times stronger than steel . And stronger than diamond.
• It is 2-dimentional crystalline allotrope of carbon.
• It’s C-C Bond length is 0.142 nm and interplanar spacing is of 0.335 nm.
4. Discovery of Graphene.
• In 2004, single-layer graphene was isolated from graphite using mechanical exfoliation,
and its carrier transport properties were reported by Geim’s research group.
• Andre Geim and Kostya Novoselov at University of Manchester extracted single-atom-
thick crystallites from bulk graphite. They pulled graphene layers from graphite and
transferred them onto thin SiO2 on a silicon wafer in a process called either
micromechanical cleavage or the scotch tape technique.
• Nobel Prize 2010 Nobel Prize in Physics for 2010 was awarded to Sir Andre Geim and
Sir Kostia Novoselov “for ground-breaking experiments regarding the two-dimensional
material graphene”.
• Fig(a)- Kostya Novoselov and fig(b)- Andre Geim.
5. Properties of Graphene.
• It has High Electron Mobility at room temperature, with
reported values in excess of 15,000 cm2/Vs
• Intrinsic graphene is a semi-metal or zero-gap
semiconductor .
• And it has low resistivity and better current capacity &
temperature conductivity.
• It can be used as a battery which charges very fast.
6. • It is lighter than cotton.
• Graphene burns at very low temperature and most reactive from of
carbon.
• It’s Electronic properties are Zero-overlap semi metal, High frequency operation
and High charge mobility.
• Graphene is flexible(Can Flex 20% without damage).
• Each layer is 1 atom thick which gives unique electrical and computing properties.
• It is Transparent (97.3 % Transparent).
7. Advantages
In BIOLOGICAL ENGINEERING
• Large Surface Area.
• High Electrical Conductivity .
• Efficient Bioelectric Sensory Devices .
• Able to monitor Glucose level, cholesterol DNA sequencing, Hemoglobin level etc.
• Toxic Graphene acts as anti-cancer treatment .
• And in process of Tissue Regeneration .
8. It is Super Capacitor
• It has high surface area to weight ratio (2600 m2 /g) .
• High conductivity and measured specific capacitance 135 F/g Uses .
• It is used in electric vehicles and backup powering.
• Has high power capability.
• In cell phones, Ultra super capacitors which are 100 years old technology are enhanced
by modern materials based on polarization of electrolytes, high surface area electrodes
and extremely small charge separation of ECDL (Electro Chemical Double Layer).