PLASTIC PLASTIC ELECTRONICSELECTRONICS

RajshekaRRajshekaR

EC-2EC-2

IntroductionIntroduction

Plastic is considered as an insulator, a material that Plastic is considered as an insulator, a material that doesn't conduct electricity very well. doesn't conduct electricity very well.

In fact prior to the 1970s, all synthetic polymers were In fact prior to the 1970s, all synthetic polymers were considered as electrical insulators.considered as electrical insulators.

In 1978, a landmark paper described treating In 1978, a landmark paper described treating polyacetylene with halogens, and in doing so polyacetylene with halogens, and in doing so increased its electrical conductivity to almost the increased its electrical conductivity to almost the level of a poor metallevel of a poor metal

This opens the gateway of plastic electronics This opens the gateway of plastic electronics

Disadvantages of Conventional Disadvantages of Conventional SemiconductorsSemiconductors

Manufacturing silicon requiresManufacturing silicon requires High temperatures (400-1400High temperatures (400-1400°°C).C). High vacuum environments.High vacuum environments. Very clean environments.Very clean environments.

This increases the cost of production.This increases the cost of production. Conventional electronic devices are rigidConventional electronic devices are rigid

Advantages of Plastic ElectronicsAdvantages of Plastic Electronics

Can be manufactured easily under ordinary Can be manufactured easily under ordinary conditions.conditions.

More compatible with manufacturing More compatible with manufacturing processes that use other plastics.processes that use other plastics.

Renowned for their excellent mechanical Renowned for their excellent mechanical properties, such as strength and flexibility.properties, such as strength and flexibility.

Cheap and light, useful features for biomedical Cheap and light, useful features for biomedical and other portable applications.and other portable applications.

Feature of plasticsFeature of plastics

StrengthStrength FlexibilityFlexibility Light weightLight weight Malleability.Malleability. Low costLow cost

The Chemistry behindThe Chemistry behind …… Conventional plastic is a lousy conductorConventional plastic is a lousy conductor Loose molecular bonds, which make the Loose molecular bonds, which make the

material so flexible, make it more difficult for material so flexible, make it more difficult for the electrons to travel through it.the electrons to travel through it.

But arranging polymer molecules into long, But arranging polymer molecules into long, straight rods lets electrons flow freely, straight rods lets electrons flow freely, approximating the conductivity of traditional approximating the conductivity of traditional materials like silicon or copper. materials like silicon or copper.

Molecular Model of a PolymerMolecular Model of a Polymer

Mobility FeaturesMobility Features

mobility of a typical conducting plastic used to mobility of a typical conducting plastic used to be around 0.1 cmbe around 0.1 cm22 / volts/ volts

Recently, a new class of polymers (pentacene) Recently, a new class of polymers (pentacene) has been found in which the mobility has been has been found in which the mobility has been pushed up to 3 cmpushed up to 3 cm22/volts./volts.

Scientists working on pentacene estimate a Scientists working on pentacene estimate a number close to 50 cmnumber close to 50 cm22/volts as the limit of /volts as the limit of achievable mobility for this special polymerachievable mobility for this special polymer

Constructional DetailsConstructional Details

Dielectric layers are made from conventional, Dielectric layers are made from conventional, electrically insulating polymers.electrically insulating polymers.

Conjugated polymers are used for the semi-Conjugated polymers are used for the semi-conducting components.conducting components.

Electrodes & interconnects are fabricated Electrodes & interconnects are fabricated from highly doped conducting polymers.from highly doped conducting polymers.

sp2 hybridized structure sp2 hybridized structure

Applications of Plastic Electronics Applications of Plastic Electronics

PolyLEDPolyLED Plastic TransistorsPlastic Transistors Plastic Solar CellsPlastic Solar Cells Plastic LASERsPlastic LASERs

Polymer Light-Emitting Diode Polymer Light-Emitting Diode PolyLEDPolyLED

Light is transmitted in all directions with the Light is transmitted in all directions with the same intensitysame intensity

Consume much less power than today's Consume much less power than today's devices.devices.

High contrast and brightness to make a high-High contrast and brightness to make a high-quality display that can be read easily in both quality display that can be read easily in both bright and dark environmentsbright and dark environments

Don't break when dropped Don't break when dropped

Structure & Working of PolyLEDStructure & Working of PolyLED

Plastic TransistorsPlastic Transistors

Thin Film TransistorThin Film Transistor

Working of TFTWorking of TFT

Plastic Solar CellsPlastic Solar Cells

At the heart of all photovoltaic devices are two At the heart of all photovoltaic devices are two separate layers of materials,separate layers of materials,

one with an abundance of electrons ;"negative one with an abundance of electrons ;"negative pole," :- poly(3-hexylthiophene), or P3HTpole," :- poly(3-hexylthiophene), or P3HT

one with an abundance of electron holes one with an abundance of electron holes "positive pole.“:- Cadmium Selenide (CdSe) "positive pole.“:- Cadmium Selenide (CdSe)

Plastic LASERsPlastic LASERs

The Future of Lasers is PlasticThe Future of Lasers is Plastic . Lightweight "plastic lasers" would be cheaper, . Lightweight "plastic lasers" would be cheaper,

easier and safer to make than semiconductor lasers. easier and safer to make than semiconductor lasers. produce all the colors rainbowproduce all the colors rainbow shaped easily into films, rings, microscopic discs or shaped easily into films, rings, microscopic discs or

any desired shape for various uses, any desired shape for various uses, plastics act as their own cavities, not only emitting plastics act as their own cavities, not only emitting

laser light but containing and focusing it.laser light but containing and focusing it.

Conclusion:Conclusion: In conclusion, while many obstacles still remain in In conclusion, while many obstacles still remain in

the development of plastic electronic devices, the the development of plastic electronic devices, the applications of these devices are not just science-applications of these devices are not just science-fiction. fiction.

There is little doubt that, 'plastic electronics' will There is little doubt that, 'plastic electronics' will become part of our lives within the next decade.become part of our lives within the next decade.

Chemists will be vital members of the Chemists will be vital members of the interdisciplinary teams that do this work. interdisciplinary teams that do this work.

Within the next decade, we will see plastic electronic Within the next decade, we will see plastic electronic devices giving intelligence to objects around us and devices giving intelligence to objects around us and significantly changing our lifestyle, just like the significantly changing our lifestyle, just like the invention of plastics did in the twentieth centuryinvention of plastics did in the twentieth century

Thank youThank you