- Polymers are typically insulators but can become conductive through methods like conjugated bonding and doping. Alan Heeger, Alan MacDiarmid, and Hideki Shirakawa discovered that doping could make polymers conductive like metals or semiconductors. - There are three main types of polymers: thermoplastics, thermosets, and elastomers. Conductive polymers are called that when doped and can have metallic or semiconductor conductivity. The two main doping methods are p-type and n-type doping. - Applications of light-emitting polymers include displays for devices, as they are flexible, lightweight, transparent, and more environmentally friendly than other options

2. 
 Organic Compounds made from Monomers.
 Polymers are substances containing a large number
of structural units joined by the same type of linkage.
 Three main types of Polymers:
 Thermoplastic (Linear)
 Thermosets (Branched)
 Elastomers (Cross Linked)
 Polymers are generally considered as Insulators
Polymers

3. 
Alan J. Heeger, Alan G. MacDiarmid and Hideki Shirakawa have
changed this view with their discovery that polymers can be made
conductive almost like a metal

4. 
Conduction
10-20
10-16
10-12
10-8
10-4
100 104
Conductivity ( -1
cm-1
)
copper
germanium
silicon
glass
nylon
Teflonquartz
MetalsSemiconductorsInsulators

5. 
 Denesity of charge carriers.
 Thier mobility.
 The direction.
 Presence of doping materials (additives that facilitate the
polymer conductivity)
 Temperature.
Factors that affect the conductivity

6. 
 Organic polymers that conduct electricity are called
conducting polymers.
 Such compounds may have metallic conductivity or
can be semiconductors.
 The biggest advantage of conductive polymers is
their process ability.
Conductive Polymers

7. 
 In becoming electrically conductive, a polymer has to
imitate a metal.
 That is, its electrons need to be free to move and not
bound to the atoms.
 Polyacetylene is the simplest possible conjugated
polymer.
 It is obtained by polymerisation of acetylene.
How can Polymers become conductive?

8. 
1. Conjugate Bonding
 The polymer should consists of alternating single and
double bonds, called conjugated double bonds.
 Every single bond contains a localised “sigma” (σ) bond
which forms a strong chemical bond.
 In addition, every double bond also contains a less
strongly localised “pi” (π) bond which is weaker.
Two Methods to become conductive

9. 
2. Doping
 The role of a dopant is to either add or remove
electrons to the polymer
 There are Two main types of doping.
Two Methods to become conductive

10. 
 P-type Doping (Oxidation with Halogens)
 The oxidizing agents for P-doping are like iodine
vapors, I₂ dissolved in CCl₄ , HBF₄, HClO₄ , Br₂..etc.
 The conduction in this type of doping increases up to
10⁵ s/cm.
Types of Doping
    
 3
2
3
ICHI
x
CH nn

11. 
 N-type Doping (Reduction with Alkali Metals)
 The reducing agents for n-doping are like Na metal
,FeCl₂, lithium metal ,sodium naphtha ide..etc.
 Negative charge resonates throughout the chain and
transferred to neighboring chains through Na⁺ during
conduction.
Types of Doping
    
 xNaCHxNaCH
x
nn

12. 
Conductive Polymers

13. 
Types of Conductive Polymers

14. 

15. 

16. 

17. 
 For conductance free electrons are needed.
 Conjugated polymers are semiconductor materials while doped
polymers are conductors.
 The conductivity of conductive polymers decreases with falling
temperature in contrast to the conductivities of typical metals,
e.g. silver, which increase with falling temperature.
 Today conductive plastics are being developed for many uses.
Conclusion

18. 
smart" windows
Shield for computer screen
against electromagnetic
"smart" windows
radiation
Light-emitting diodesSolar cell
Photographic film

20. 
 A light emitting polymer is an electro-luminescent plastic. The
molecules of this plastic emit light when an electric field is applied.
 Polymer based light-emitting diodes (LED) were discovered in 1990.
 Cambridge Display Technology has the core patents for the
Technology of LEP
 Poly p-phenylenevinylene
 LEP can be used in Laptop screens, cell phones, TV screens,
calculators, digital cameras, and in a future almost everything.
Introduction

21. 
 Thin film of semiconducting
polymer sandwiched between an
ANODE and CATHODE.
 ANODE: ITO(Indium Tin Oxide)
 CATHODE: Metals (depends upon
the type of LEP)
 SUBSTRATE: Glass, clear plastic
(depends upon the type of LEP)
 Voltage is applied between anode
and cathode
Polymer
Metal Cathode
Glass Substrate
Transparent Anode (ITO)

22. 
 Spin Coating Method
 Ink Jet Printing Method
HOW IT IS MADE

23. 
 Flexible Organic Light Emitting Polymers(FOLEP).
 Stacked Organic Light Emitting Polymers(SOLEP)
 Transparent Organic Light Emitting
Polymers(TOLEP)
Types of LEP

24. 
 Built on a flexible substrate.
 They have the ability to conform, bend or roll a
display into any shape.
 They are less fragile and more impact resistant.
 Ultra lightweight & thin form
Flexible organic LEP(FOLEP)

25. 

26. 
 Substrate is transparent.
 LEPs sandwiched between 2 transparent layers.
 Top and bottom emitting layers.
 High resolution.
 More than 70% transparent when turned off.
 Better efficiency.
 Faster response
Transparent organic LEP(Tolep)

27. 
 Array of vertically stacked TOLEP sub-pixels.
 Color is tuned by individually controlling R-G-B sub pixels
 Brightness is adjusted by adjusting the total current in the stack.
 It will only turn on the desired color pixel only.
 Can be used in large displays
 True color quality.
Stacked organic LEP(SOLEP)

28. 
Comparison with LCD
 Screen Refreshing Rates
 Viewing quality
 Screen size
 Viewing angle
 Power consumption
 Higher than LCD
 Higher than LCD
 Size is not limited in
LEP display
 Glare free up to 170
degree
 Lesser than LCD

29. 
ADVANTAGES
 Require only 3.3v & life time of more than 30,000 hr.
 Low power consumption.
 Self luminous.
 No viewing angle dependence.
 Manufacturing cost is less.
 Can be scaled to any dimension.
 No environmental draw backs.
 Simple to use.
 Very slim flat panel displays.

30. 
Disadvantages
 Voltage drops may affect the performance.
 Limited market availability.
 Aging of LEP
 Degradation of luminescence
 Light intensity gradually decreases.
 Disintegrate due to contact with oxygen.

31. 
 Multi or full color cell phone displays
 Full color high-resolution personal digital
assistants(PDAs)
 Lightweight wrist watches
 Roll-up daily refreshable electronic newspapers
 Automobile light systems without bulbs
Applications

32. 
FUTURE SCOPES

33. 
 Have both electrical and optical property
 A low cost solution for flat panel display.
 Many manufactures are working to introduce a revolutionary
changes in the market.
 Hazardless to environment.
 Simpler and cheaper
 Have some limitations
 Till it is the superior technology for the future.
CONCLUSION

34.  H. Shirakawa, E.J. Louis, A.G. MacDiarmid, C.K. Chiang and A.J.
 Heeger, J Chem Soc Chem Comm (1977) 579
 T. Ito, H. Shirakawa and S. Ikeda, J.Polym.Sci.,Polym.Chem. Ed. 12
 (1974) 11–20
 C.K. Chiang, C.R. Fischer, Y.W. Park, A.J. Heeger, H. Shirakawa, E.J.
 Louis, S.C. Gau and A.G. MacDiarmid , Phys. Rev. Letters 39 (1977)
 1098
 C.K. Chiang, M.A. Druy, S.C. Gau, A.J. Heeger, E.J. Louis, A.G.
 MacDiarmid*, Y.W. Park and H. Shirakawa, J. Am. Chem. Soc. 100
(1978) 1013
 Evaristo Riande and Ricardo Díaz-Calleja, Electrical Properties of
Polymers
 http://nobelprize.org/nobel_prizes/chemistry/laureates/2000/index.html
 http://www.organicsemiconductors.com
Bibliography

35. 