1. PHYSICAL ELECTRONICS EEE2056
TRIMESTER 2, 2015/2016 SESSION
TITLE: GRAPHENE AND ITS APPLICATIONS

2. What Is Graphene?
In basic terms, graphene, is a slim layer of pure carbon; it is a solitary, firmly pressed layer of carbon atoms that are bounded together in a hexagonal honeycomb lattice In more complex terms, it is an allotrope of carbon in the structure of a plane of sp2 bonded atoms with a molecule bond length of nanometers.
The Structure Of Graphene
Graphene is a crystalline allotrope of carbon with 2 dimensional properties. Each carbon has 4 bonds, 1 sigma with each of its 3 neighbor and 1 pi bond i.e. oriented out of the plane.

3. Properties Of Graphene
  ELECTRICAL PROPERTIES
Graphene is very importance in many ways and a significant standout amongst the most valuable properties of Graphene is that it is a zero-overlap semimetal (with both hole and electrons as charge carriers) with high electrical conductivity. There are a total sum of 6 electrons present in carbon atoms;
MECHANICAL STRENGHT
 Another of graphene's good properties is its intrinsic quality. Because of the quality of its Nm-long carbon bonds, graphene is the most STRONGEST material ever found, with an extreme elasticity of 130,000,000,000 Pascals (or 130 gigapascals), compared with 400,000,000 for A36 structural steel, or 375,700,000 for Aramid (Kevlar

4. OPTICAL PROPERTIES
  Because to the amazing of qualities of graphene, it has been watched that once optical power achieves a certain threshold known as the saturation fluence saturable absorption happens. This is an imperative characteristic with respect to the mode-locking of fiber lasers
HEAT PROPERTIES
Graphene has to a great degree high intrinsic thermal conductivity. Small expansion of the liquid-phase exfolaited graphene can increase thermal conductivity of composite materials. Composites with graphene and nanoparticles fillers can be both electrically insulating and conducting. Graphene composites are promising as thermal interface materials (TIMs.

5. Application Of Graphene
 Graphene quantum dot – light emitting diode:
The luminescent way of graphene quantum dots has likewise made it a contender for light-discharging diodes. The structure of a LED looks like a solar cell, yet it has a reverse physical function: carriers are energized by an external electrical field and quickly recombine, producing lu-minescence.
Lithium Ion Battery
  Lithium ion battery has been a key component of hand-held devices due to its renewable and clean nature. To meet the increasing demand for lithium ion batteries with higher energy density and durability, new electrode materials with higher capacity and stability have been developed. Paek et al. has prepared graphene Nano sheets decorated with SnO2 nanoparticles

6. Fuel cell and solar cell
Graphene materials have also been used in fuel cells and solar cells. Graphene has been identified as a catalyst support for oxygen reduction and methanol oxidation in case of a fuel cell configuration. Conductive graphene scaffolds for platinum nanoparticles facilitates competent collections and transfer of electrons to electrode surface.
Cancer Therapy
  Due to its distinct conjugated structure, large surface area and relatively low costs, graphene has open a new platform in the field of pharmacological applications in-vitro and in vivo. Graphene and its derivatives have been utilized in several biomedical fields including anti-cancer therapy.

7. Ultra-Capacitor
 EDLCs are non-faradic ultra-capacitor which store charges in electric double layers made at the interface between a high surface area electrode and an electrolyte. Activated carbon with high specific surface area is extensively used as electrode material in EDLCs.
Transparent Conductive Films
  With high electrical conductivity, high carrier mobility and moderately high optical transmittance in the visible range of spectrum, graphene material show promise for transparent conductive films (TCFs) and is expected to be one of the mostly sought material for future optoelectronic devices.
Is Graphene dangerous?
There has been reports about Graphene which classified it as a natural bio-compatible carbon component. However, On account of Graphene, Ken Donaldson is a respiratory toxicologist at the University of Edinburgh and he and his associates are among the first to raise the cautioning banner on Graphene.
Usefulness:
I have been wating for some time now to write a headline along the lines of “scientist discover things that graphene is not amazing at” and here it is.it could also be bad for the environment and bad for you, too.