G.H Raisoni College Of Engineering(An Autonomous Institute under UGC act 1956,affilated to RTMNU, Nagpur)

Department of Electronics Engineering

Application Of Graphene In Modern Electronics

Presented By-Chinmay Chepurwar

PAPER PRESENTATION ON

Overview

Lets know Graphene History Structure Properties What makes Graphene different from others? Fabrication technique Applications How it will change electronics??

So,Whats Graphene???

Worlds’ first 2D crystal.Latest invented allotrope of CarbonNoble Prize for Physics 2010Single layer hexagonal structure.Obtained from simple and abundant form of carbon graphite . Thinnest ever material in the world.

The Graphene

Electron microscopic image on Sio2 surface

The inventers 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 for physics.

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

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

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

In 1960’s it was believed that physically graphene cannot exist abecause of thermodynamic unstability

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

History

Structure of Graphene

Sheets of graphene are bonded by loose bond in graphite. These bonds are broken and sheets are isolated to form graphene. These isolated hexagonal sheets are graphene.

Salient features of the structure

2D Hexagonal structure. Van der wall’s force of attraction. Strong bonds. Bond length 0.142 nm. Long chain of interlinked,hexagonal

lattice.

Properties of Graphene

PhysicalElectricalElectronicOpticalThermalMechanical

Physical properties of Graphene

Density- density of graphene 0.77 mg/m2.

Strength- With its breaking strength 42 N/m it is 1000 times stronger than steel.

Optical transparency- graphene is almost transparent with its ability of absorb just 2.3% of light falling on it.

Thinnest possible material

Electrical propertiesDifferent electronic structure. High electrical conductivity.Conductivity further can be increased by

applying electric field. electrical conductivity of sheets are 10 times

that of copper. Best known conductor till now

Electronic propertiesGraphene 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 propertiesUnexpectedly high opacity for an atomic monolayer

it 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

 Due to this special property, graphene

has wide application in ultrafast photonics

Thermal properties

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

Bulk strength is 130GPa200 times greater

than steel

Graphene sheets, held together by van der Waals forces

What makes Graphene different from others???

Unique structure. All in one properties. Low cost. Abundant element. Simple fabrication techniques. Chemically inert. Thermal stability.

peeling off layers of graphite with a sticky tape

Mechanical cleavage

optical microscope image ofresulting flakes

Fabrication Technique

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

Fullerenes Nanotubes Sheets

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

Applications in electrical engineering.Mechanical engineering.Most important in electronics engineering as component

material.As a superconducting material.Micro electronics.Transparent conducting electrode.Solar cellsGraphene biodevices.

Applications

Electrical engineering

Can replace graphite in brushes of motors.Can be construction material for various electrical devices.When mixed with plastic can be used as conductor with

higher strength. It will replace copper as conducting material.

Mechanical engineering

In Manufacturing process as Manufacturing material.As a composite material for machines ,cars.Defense. Airplanes, space shuttles , satellite.

Electronics Engineering

Will definitely replace silicon and germanium as device material.

Conducting material on PCBs.Single molecule sensorsTouchscreensGraphene transistor.Graphene integrated circuits.Graphene chips.

Solar cells The large scale production of highly transparent

graphene films by chemical vapour deposition three years ago. In this process, researchers create ultra-thin graphene sheets by first depositing carbon atoms in the form of graphene films on a nickel plate from methane gas. Then they lay down a protective layer of thermo plastic over the graphene layer and dissolve the nickel underneath in an acid bath. In the final step they attach the plastic-protected graphene to a very flexible polymer sheet, which can then be incorporated into a OPV cell (graphene photovoltaics).

High transperancy will increase efficiency of solar cells

Graphene Biodevices

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 devices. 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

Nanopore-based single-molecule DNA sequencing.

Fabrication of electronic devices

Graphene when converted into nanoribbon and nanotubes will replace silicon as semiconducting material.

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.

Graphene has excellent properties to be a vital component of integrated circuits

Graphene transistors are conceivable and are ready to replace silicon transistors

In 2009 researchers demonstrated four different types of logic gates, each consisting of a single graphene transistor

It is capable of taking an incoming electrical signal of a certain frequency and an producing output signal that is a multiple of that frequency

A recent publication has described a process for producing gram-quantities of graphene, by the reduction of ethanol by sodium metal, followed by pyrolysis of the ethoxide product, and washing with water to remove sodium salts.

Graphene biodevices

Anti-bacterial

POTENTIAL APPLICATIONS OF GRAPHENE

Single molecule gas detection

Graphene nanoribbons

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

Better sports equipmentStronger medical implantsEmbedding the material in plastics to enable them to conduct electricity Increasing the efficiency of electric batteries by use of graphene powderOptoelectronicsLeak-tight, plastic containers that keep food fresh for weeksTransparent conductive coatings for solar cells and displays Super capacitors Improved conductivity of materialsHigh-power high frequency electronic devicesReplacing silicon in transistorsOrganic light-emitting diodes(OLED)sGraphene nanoribbons could be a way to construct ballistic transistors

Graphene at its best

THANK YOU !!!