![© 3/52
Printed Conjugated Polymers
How an Organic Transistor WorksTransistors
IPCs
Printing
Materials
Results
Applications
Outlook
© PolyIC 2004
S D
G
NNN N
H H
H H
[ ]no+o+
o- o-AA
Polyaniline (PAni)
Electrodes
conducting polymer
or metal
OH
( )
n
Polyhydroxystyrene (PHS)
Insulator
insulating polymer
n
)( S
R
S
R
S
R
S
R
Poly-3-alkylthiophene (P3AT)
Semiconductor
conjugated polymer
COCH2CH2OC
O O
n
)(
Polyester
Substrate
flexible film
VGS
VDS
Channel due to
electric field](https://image.slidesharecdn.com/overview-poe-2005-160202102044/85/Overview-poe-2004-3-320.jpg)
![© 15/52
Printed Conjugated Polymers
Electrodes: Polyaniline (PANI) and
Poly(3,4-ethylenedioxythiophene)
(PEDOT)
NNN N
H H
H H
[ ]no+o+
o- o-AA
Doped Polyaniline (PANI)
Poly(styrene sulfonic acid)
Poly(3,4-ethylenedioxythiophene)
Baytron P*
*L. B. Groenendaal et alt., Adv. Mater., 12, n.7 (481-493), 2000
Transistors
IPCs
Printing
Materials
Results
Applications
Outlook](https://image.slidesharecdn.com/overview-poe-2005-160202102044/85/Overview-poe-2004-15-320.jpg)
![© 21/52
Printed Conjugated Polymers
Materials for Polymer Electronics
Organic Conductors and Semiconductors
Nobel Prize in 2000 for the discovery of organic conductors
regioregular Poly(3-hexylthiophen)
solution processable
Pentacen
high values for vacuum deposition
10
-5
10
-4
10
-3
10
-2
10
-1
1 10
µ [ cm2
/Vs ]
α
-
Si
σ [ S/cm ]
10 5
10 4
10 3
10 2
10 1
10 0
10-1
10 6
Comp.: Copper
Polyacetylene
Polyaniline
PEDOT
b) Charge carrier mobility (µ) of special organic semiconductors
a) Conductivity (σ) of special organic conductors
n
)( S
R
S
R
S
R
S
R
regioregular Poly(3-hexylthiophen)
solution processable
Pentacen
high values for vacuum deposition
10
-5
10
-4
10
-3
10
-2
10
-1
1 10
µ [ cm2
/Vs ]
α
-
Si
σ [ S/cm ]
10 5
10 4
10 3
10 2
10 1
10 0
10-1
10 6
Comp.: Copper
Polyacetylene
Polyaniline
PEDOT
b) Charge carrier mobility (µ) of special organic semiconductors
a) Conductivity (σ) of special organic conductors
n
)( S
R
S
R
S
R
S
R
Pentacene
High values for vacuum deposition
Regioregular poly(3-hexylthiophene)
Solution processable
© PolyIC 2004
Transistors
IPCs
Printing
Materials
Results
Applications
Outlook](https://image.slidesharecdn.com/overview-poe-2005-160202102044/85/Overview-poe-2004-21-320.jpg)
Overview poe-2004
- 1. Printed Plastic Electronics Effects of printing on conjugated polymer’s conduction mechanisms IFN - CNR January, 27th 2004 Alessandro Manuelli
- 2. © 2/52 Printed Conjugated Polymers Overview Brief introduction to transistors and their characteristics How a transistor works Remarkable output characteristics Integrated plastic circuits (IPCs) Printing techniques Requirements for a printing process Processes considered Continuous printing process Suitable materials Theories about conduction Interesting polymers Importance of the morphology Effects of printing and coating on conducting mechanisms Impedance spectroscopy Thermal induced transitions in PANI Printed PANI Coated and printed semiconductors Applications Outlook
- 3. © 3/52 Printed Conjugated Polymers How an Organic Transistor WorksTransistors IPCs Printing Materials Results Applications Outlook © PolyIC 2004 S D G NNN N H H H H [ ]no+o+ o- o-AA Polyaniline (PAni) Electrodes conducting polymer or metal OH ( ) n Polyhydroxystyrene (PHS) Insulator insulating polymer n )( S R S R S R S R Poly-3-alkylthiophene (P3AT) Semiconductor conjugated polymer COCH2CH2OC O O n )( Polyester Substrate flexible film VGS VDS Channel due to electric field
- 4. © 4/52 Printed Conjugated Polymers OFET - Output Characteristics © PolyIC 2004 Saturation λ Important parameters Contact resistance Mobility Leakage currents ON/OFF ratio A fast way for testing circuits or which parameter tells what ? Transistors IPCs Printing Materials Results Applications Outlook
- 5. © 5/52 Printed Conjugated Polymers Spin coating 2. Semiconductor P3AT Spin coating 3. Insulator Lithography 4. Gate- electrode: Gold : Lithography 1. S/D-electrodes Gold Cleanroom class 100 Spincoating P3AT *J. Ficker et al., Proc. of SPIE, 4466 (2001), 95-102 A. Ullmann et al., Mat. Res. Soc. Symp. Proc., 665 (2001), C7.5.1 Development with Photo Lithography Rapid prototyping process © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 6. © 6/52 Printed Conjugated Polymers SPIE 2003 San Diego GND - • 192 kHz (at -60V) • stage delay 370 ns • L = 2.6 µm • 15 OFETs (7 stages), 10 Vias Layout: Results: f ~ µ * U / L² © PolyIC 2004 Results with Photo lithography Ring oscillators Transistors IPCs Printing Materials Results Applications Outlook
- 7. © 7/52 Printed Conjugated Polymers Comparison of frequency of organic based integrated circuits: Improvement from 2001 to 2002 © PolyIC 2004 Technology Comparison of ring oscillator performances Infineon 4,7 kHz 2002 3,5 kHz 2001 Philips Philips 2 kHz 2001 60 Hz 2001 PolyIC 200 kHz 2002 106 kHz 2001 600 kHz 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 8. © 8/52 Printed Conjugated Polymers conventional digital relief planar gravure screen ink jet electrogr. thermalmagnetho. • letterpress • flexoprinting • offset • pad printing • continuous • drop-on- demand • xerography similiar to • transfer • sublimation printing techniques “the world of printing meets the world of electronics” © PolyIC 2004 Printing of Polymer Chips Demand for high quality printing processes Transistors IPCs Printing Materials Results Applications Outlook
- 9. © 9/52 Printed Conjugated Polymers < 1 µm Printing of Polymer Chips Layer configuration and dimensions of Organic Field Effect Transistor 10 µm Drain Source ca. 100 µm Gate “More accuracy required for printing techniques” © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 10. © 10/52 Printed Conjugated Polymers Lab printing with standard printing methods: • first attempts towards printed electronics Gravure offset printing: high resolution electrodes Screen printing: homogeneous films Printing proofer: gravure printing flexo printing coating: homogeneous films © PolyIC 2004 Development of Printing Techniques Lab. printing and coating techniques Transistors IPCs Printing Materials Results Applications Outlook
- 11. © 11/52 Printed Conjugated Polymers cliché pad doctor blade ink 20 µm resolution Pad printing Printed Source / Drain structures 1) 2) Source Drain © PolyIC 2004 Development of Printing Techniques Lab. Printing: pad printing for high resolution Transistors IPCs Printing Materials Results Applications Outlook
- 12. © 12/52 Printed Conjugated Polymers Blade with a fixed slit and moved by an engine with a constant speed Substrate Semiconductor Doctor blade Insulator Substrate Doctor blade Development of Printing Techniques Lab printing: doctor blade for homogeneous coating © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 13. © 13/52 Printed Conjugated Polymers Development of Printing Techniques Lab printing: flexography for a continuous process “A good potential in term of resolutions and speed” Ink bath Anilox cylinder Doctor blade Printing cylinder with flexible stereo Web © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 14. © 14/52 Printed Conjugated Polymers Development of Printing Techniques The research machine for testing continuous processes Under construction Finished with its enclosure and air filtration © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 15. © 15/52 Printed Conjugated Polymers Electrodes: Polyaniline (PANI) and Poly(3,4-ethylenedioxythiophene) (PEDOT) NNN N H H H H [ ]no+o+ o- o-AA Doped Polyaniline (PANI) Poly(styrene sulfonic acid) Poly(3,4-ethylenedioxythiophene) Baytron P* *L. B. Groenendaal et alt., Adv. Mater., 12, n.7 (481-493), 2000 Transistors IPCs Printing Materials Results Applications Outlook
- 16. © 16/52 Printed Conjugated Polymers Semiconductors Based on Polythiophenes n )( S R S R S R S R Poly-3-alkylthiophene regioregular, commercial *M. C. Magnoni et alt., Acta Polymer. 47, (228-233), 1996 Poly(3,3”-dihexyl-2,2’:5’,2”-terthiophene)* Transistors IPCs Printing Materials Results Applications Outlook
- 17. © 17/52 Printed Conjugated Polymers Structure of Semiconducting Polymers Space-filling models of P3OT chains Stick model of one P3OT chain Poly(3-octylthiophene) (P3OT) n )( S R S R S R S R © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 18. © 18/52 Printed Conjugated Polymers Theory of Band Conduction* *D. O. Cowan et alt., C&EN special report, July 21 (28-45),1986 Eg Eg E m pt y le ve ls Fil le d le ve ls Insulator Semiconductor Metal Schematic representation of the allowed energy states for an insulator, semiconductor, and metal. The boxes indicate the allowed energy regions. Coloured areas represent regions filled with electrons. Regions between the boxes represent forbidden energy levels and Eg is the energy gap between filled and empty states. Transistors IPCs Printing Materials Results Applications Outlook
- 19. © 19/52 Printed Conjugated Polymers Bipolarons in Polymers Dication (bipolaron, bound, no spin) Radical cation (polaron, spin) S S S S S S S S -e- S S S S S S S S -e- S S S S S S S S Polythiophene QB B Formation of polaron during the oxidation process of a polythiophene. Conduction bands Valence bands Neutral polymer has full valence and empty conduction bands Removal of one electron forms polarons Removal of second electron forms bipolaron Removal of more electrons forms bipolaron bands Increased doping produces bipolarons bands and removes states from both the valence and conduction band. Transistors IPCs Printing Materials Results Applications Outlook
- 20. © 20/52 Printed Conjugated Polymers Band conduction X Conduction allowed only in empty bands Ef Ef Ef Ef V V Electrode Electrode Electrode Transistors IPCs Printing Materials Results Applications Outlook
- 21. © 21/52 Printed Conjugated Polymers Materials for Polymer Electronics Organic Conductors and Semiconductors Nobel Prize in 2000 for the discovery of organic conductors regioregular Poly(3-hexylthiophen) solution processable Pentacen high values for vacuum deposition 10 -5 10 -4 10 -3 10 -2 10 -1 1 10 µ [ cm2 /Vs ] α - Si σ [ S/cm ] 10 5 10 4 10 3 10 2 10 1 10 0 10-1 10 6 Comp.: Copper Polyacetylene Polyaniline PEDOT b) Charge carrier mobility (µ) of special organic semiconductors a) Conductivity (σ) of special organic conductors n )( S R S R S R S R regioregular Poly(3-hexylthiophen) solution processable Pentacen high values for vacuum deposition 10 -5 10 -4 10 -3 10 -2 10 -1 1 10 µ [ cm2 /Vs ] α - Si σ [ S/cm ] 10 5 10 4 10 3 10 2 10 1 10 0 10-1 10 6 Comp.: Copper Polyacetylene Polyaniline PEDOT b) Charge carrier mobility (µ) of special organic semiconductors a) Conductivity (σ) of special organic conductors n )( S R S R S R S R Pentacene High values for vacuum deposition Regioregular poly(3-hexylthiophene) Solution processable © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 22. © 22/52 Printed Conjugated Polymers Regioregularity, Orientation and Alignment Sirringhaus et alt., Nature 401, 685 (1999) Charge flow S S S S S S S S Low regioregularity High regioregularity Charge flow S S S S S S SS 10-1 10-4 µ 70 98 %HT © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 23. © 23/52 Printed Conjugated Polymers Supramolecular Order of Functional Polymers* *R. D. McCullough et alt., Handbook of Conducting Polymers, Second Edition Transistors IPCs Printing Materials Results Applications Outlook
- 24. © 24/52 Printed Conjugated Polymers Polycrystallinity in PolymersTransistors IPCs Printing Materials Results Applications Outlook
- 25. © 25/52 Printed Conjugated Polymers Impedance Spectroscopy Input: V = Vm·eiωt Output: I = Im·eiωt’ Y(ω) = Im·eiωt’ / Vm·eiωt = (Im/Vm) · eiωt’-iωt = Ym · eiψ Ym= admittance ψ = ω∆t Z(ω) = 1/Y = (1/Ym) · e-iψ = Z’ - i Z’’ Z’ = Zm cos(ψ) Z’’ = Zm sen(ψ) Transistors IPCs Printing Materials Results Applications Outlook
- 26. © 26/52 Printed Conjugated Polymers Impedance Spectroscopy Equivalent circuits Transistors IPCs Printing Materials Results Applications Outlook
- 27. © 27/52 Printed Conjugated Polymers Impedance Spectroscopy Plot Recorded plot Equivalent circuit Transistors IPCs Printing Materials Results Applications Outlook
- 28. © 28/52 Printed Conjugated Polymers Conducting Polymers Non ohmic conductivity in coated PANI A l L1 R1 R2 C1 R3 CPE1 R4 C3 W1 Element Freedom Value Error Error % L1 Free(±) 6,5029E-6 N/A N/A σ = 14 S/cm r. h. 0% 500 1000 1500 2000 2500 -1500 -1000 -500 0 500 Z' Z'' 102 103 104 105 106 107 108 102 103 104 Frequency (Hz) Z' -750 -500 -250 0 250 Z'' Transistors IPCs Printing Materials Results Applications Outlook
- 29. © 29/52 Printed Conjugated Polymers Conducting Polymers Influence of relative humidity on conductivity 0 1000 2000 3000 4000 -4000 -3000 -2000 -1000 0 Z' Z'' Time σ = 14 S/cm at r. h. 0% σ = 17.3 S/cm at r. h. 32% Conductivity increases Constant dedoping at r. h. 72% Conductivity decreases 500 1000 1500 2000 2500 -1500 -1000 -500 0 500 Z' Z'' Dry 32% Transistors IPCs Printing Materials Results Applications Outlook
- 30. © 30/52 Printed Conjugated Polymers Conducting Polymers Thermal analysis of PANI: TGA, DSC 1st run Recrystall. 2nd run TGA shows a stability of PANI over 200° C DSC shows an irreversible transition at 160° C Transistors IPCs Printing Materials Results Applications Outlook
- 31. © 31/52 Printed Conjugated Polymers Conducting Polymers UV-Vis analysis of PANI The thermal transition affects the orbitals’ energy Transistors IPCs Printing Materials Results Applications Outlook
- 32. © 32/52 Printed Conjugated Polymers Conducting Polymers Simpler conducting mechanism L1 R1 R2 CPE1 W1 Element Freedom Value Error Error % 550 600 650 700 750 -150 -100 -50 0 50 Z' Z'' 102 103 104 105 106 107 108 -30 -20 -10 0 10 20 Frequency (Hz) Z'' σ = 45 S/cm at r. h. 32% Transistors IPCs Printing Materials Results Applications Outlook
- 33. © 33/52 Printed Conjugated Polymers Conducting Polymers Rinsing treatment 300 400 500 600 700 800 900 -500 -400 -300 -200 -100 0 100 Z' Z'' Time Doping acid surfaces and affects the conductivity A rinsing step solves the problem Transistors IPCs Printing Materials Results Applications Outlook
- 34. © 34/52 Printed Conjugated Polymers Conducting Polymers Ohmic conductivity in PANI 300 400 500 600 700 -300 -200 -100 0 100 Z' Z'' r.h. 32% r.h. 72% 582,5 585,0 587,5 590,0 592,5 -7,5 -5,0 -2,5 0 2,5 Z' Z'' 102 103 104 105 106 107 108 -25 0 25 50 75 100 Frequency (Hz) Z'' r.h. 32% r.h. 72% σ = 48.5 S/cm at r. h. 32% σ = 50.0 S/cm at r. h. 72% Devices: Knobloch A. et alt., Journal of Applied Physics 96, 2286 (2004) Transistors IPCs Printing Materials Results Applications Outlook
- 35. © 35/52 Printed Conjugated Polymers Conducting Polymers Influence of the rinsing solvent and technique dry 32%72% 98% 500 750 1000 1250 1500 1750 -1000 -750 -500 -250 0 250 Z'Z'' Annealing and rinsing with acetone σ = 7 S/cm at r. h. 0% σ = 10 S/cm at r. h. 32% σ = 16 S/cm at r. h. 72% σ = 21 S/cm at r. h. 98% Spin coating, annealing, rinsing with ethanol σ = 20 S/cm at r. h. 32% Transistors IPCs Printing Materials Results Applications Outlook
- 36. © 36/52 Printed Conjugated Polymers Conducting Polymers Transistor with flexo printed D/S S/D: PANI 5% w/w in Toluene σ = 49 S/cm Semiconductor: P3HT in chloroform, spin coated Insulator: PMMA in dioxane, spin coated Gate: Au sputtered ON/OFF ratio = 4 Uth = +30 V µ = 4.5 x 10-4 cm2 /Vs Transistors IPCs Printing Materials Results Applications Outlook
- 37. © 37/52 Printed Conjugated Polymers Semiconducting Polymers Spin coating v.s. doctor blade Transistor with two doctored layers Traditional spin coated transistor Source Drain Gate D/S: Au, photolithography Semiconductor: P3HT doctored Insulator: polymer blend, doctored Gate: Au, photolithography D/S: Au, photolithography Semiconductor: P3HT, spin coating Insulator: polymer blend, spin coating Gate: Au, photolithography Manuelli A. et alt., Proceedings of Polytronic 2002, 201 (2002) Transistors IPCs Printing Materials Results Applications Outlook
- 38. © 38/52 Printed Conjugated Polymers Semiconducting Polymers Transistors’ output characteristics Doctored ON/OFF ratio = 12 Uth = +4 V µ = 2.7 x 10-2 cm2 /Vs Spin-coated ON/OFF ratio = 10 Uth = +8.5 V µ = 2 x 10-2 cm2 /Vs Transistors IPCs Printing Materials Results Applications Outlook
- 39. © 39/52 Printed Conjugated Polymers Semiconducting Polymers Flexo printed structures PDHTT 0.5% w/w in chloroform flexo-printed. (a) (b) and (c) three different kinds of structures; (d) particular of two fingerprints. (a) (b) (c) (d) Transistors IPCs Printing Materials Results Applications Outlook
- 40. © 40/52 Printed Conjugated Polymers Semiconducting Polymers AFM 1 µm 5 µm 10 µm 1 µm 5 µm 10 µm P3HT flexo printed P3HT spin coated Transistors IPCs Printing Materials Results Applications Outlook
- 41. © 41/52 Printed Conjugated Polymers Printed Electronics – Application fields two main fields RFID tags Radio Frequency IDentification - ePC* - identification - brand protection - anti theft - logistics Printed Electronic Devices - single devices - display circuits - games / give aways *ePC: Electronic Product Code © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 42. © 42/52 Printed Conjugated Polymers Applications of Polymer Chips driving circuits for displays Plastic matrix displays Flexible displays • OLED, LCD, electrochrome, others • display on „any“ electronics, ... Properties: • thin • flexible • inexpensive • large areas possible • rapid prototyping of electronics • single use possible • disposable possible Properties: • thin • flexible • inexpensive • large areas possible • rapid prototyping of electronics • single use possible • disposable possible © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 43. © 43/52 Printed Conjugated Polymers Applications of Polymer Chips marketing products, games, give aways Toys Give aways Use for: • marketing, • single use electronics • games • give aways • ... Properties: • thin • flexible • inexpensive • large areas possible • rapid prototyping of electronics • single use possible • disposable possible Properties: • thin • flexible • inexpensive • large areas possible • rapid prototyping of electronics • single use possible • disposable possible © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 44. © 44/52 Printed Conjugated Polymers Application of Polymer Chips Sensors Properties: • thin • flexible • inexpensive • large areas possible • rapid prototyping of electronics • single use possible • disposable possible Properties: • thin • flexible • inexpensive • large areas possible • rapid prototyping of electronics • single use possible • disposable possible Sensors Use for: inexpensive sensors, single use sensors, large area sensor matrices, .... © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 45. © 45/52 Printed Conjugated Polymers Application of Polymer Chips Polymer chip RFID-tags © PolyIC 2004 Sender / reader (conventional) Transponder - RFID - Tag sender/ reader Vcc GND OUT rectifier antenna RF-waves Transponder - chip Standard - Tag: medium cost medium volume IPC - Tag low cost high volume • RFID: radio frequency identification • contactless reading Transistors IPCs Printing Materials Results Applications Outlook
- 46. © 46/52 Printed Conjugated Polymers Application of Polymer Chips RFID-tags Many areas © PolyIC 2004 Identification Automation Electronic watermark Electronic tickets Logistics Electronic bar code Polymer RFID-Tags: • thin, flexible • inexpensive • onto „any“ product Polymer RFID-Tags: • thin, flexible • inexpensive • onto „any“ product Transistors IPCs Printing Materials Results Applications Outlook
- 47. © 47/52 Printed Conjugated Polymers Application of Polymer Chips RFID-tags The electronic Product Code ePC © PolyIC 2004 Electronic check-out Electronic bar code plastic transistor Functional polymers Transmitter / receiver reads information of electronic barcodes Electronic payment and logistics Shopping trolley Sender / Receiver „intelligent packages with electronic product codes“ Picture: new world Transistors IPCs Printing Materials Results Applications Outlook
- 48. © 48/52 Printed Conjugated Polymers Plastic Chips vs. Silicon Chips: Not a competition, but different fields Number of transistors per chip (approx.) Systemcosts,approx.(€) Plastics field Silicon field 1 10 103 10-1 10-2 10-3 102 1 101 102 104 105 106 107 Plastics Silicon low complexity, costs driven by: process, packaging actual tendency high complexity, costs driven by: size, density, yield approximate values © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 49. © 49/52 Printed Conjugated Polymers Chip or Chipless RFID? - Polymer Chip RFIDs are the missing link towards ePC performance volume cost transmission of information application on each good Si - Chip Polymer - Chip chipless propertiesapplications © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 50. © 50/52 Printed Conjugated Polymers The future of RFID: Lowest price - highest volume Trillions Tens of Billions Billions Hundreds of Millions Millions Tens of Thousands Thousands 2c 10c 30c $1 $10 $100 Up to 1c Active Chip Passive Chip Polymer Circuits Other Chipless Source: IDTechEx Limited, Issue 12 © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 51. © 51/52 Printed Conjugated Polymers IPCs are a new platform technology for low cost, high volume, simple applications • RFID tags - electronic product code (ePC) • printed electronic devices • single use electronics • active displays • sensors “low cost electronics for new mass markets - not a substitute for standard electronics” Printed Integrated Polymer Circuits - IPC © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook
- 52. © 52/52 Printed Conjugated Polymers A “New Electronics Revolution“ with printed electronics Vacuum tube triode 1906 Transistor 1947 Radio in every house Computer, etc. on every desk printed electronics everywhere Printed Transistor 2001 © PolyIC 2004 Transistors IPCs Printing Materials Results Applications Outlook Potential of Integrated Polymer Circuits - IPC