Influences of printing techniques on the electrical performances of conjugated polymers for organic transistors [Elektronische Ressource] / vorgelegt von Alessandro Manuelli

Sasso Sassod'Elialuca

Informations

• Publié par: technische_universitat_chemnitz
• Publié le: 01 janvier 2006
• Nombre de lectures: 11
• Langue: English
• Poids de l'ouvrage: 4 Mo

Extrait

Influences of Printing Techniques on the Electrical
Performances of Conjugated Polymers for Organic
Transistors
Von der Fakultät für Maschinenbau der
Technischen Universität Chemnitz
Genehmigte
Dissertation zur Erlangung
des akademischen Grades
Doktoringenieur
Dr.-Ing.
vorgelegt
von Diplom. Ing. Alessandro Manuelli
geborem am 14.03.1970 in Pavia
eingereicht am 20. Juli 2006
Gutachter:
Prof. Dr. Arved C. Hübler
Prof. Dr. Giuseppe Zerbi
Dr. Wolfgang Clemens
Chemnitz, den 30.11.2006Alessandro Manuelli
Thema
Influences of Printing Techniques on the Electrical Performances of Conjugated Polymers for
Organic Transistors
Dissertation an der fakultät für Machinenenbau der Technischen Universität Chemnitz, Institüt fü
Print- und Medientechnnik, Chemnitz, 30.11.2006
157 Seiten
96 Abbildulgen
3 Tabellen
254 Literaturzitate
Referat
The discovery of conducting and semiconducting polymers has opened the possibility to produce
integrated circuits entirely of plastic with standard continuous printing techniques. Nowadays
several of this polymers are commercial available, however the performances of this materials are
strongly affected by their supramolecular order achieved after deposition. In this research, the
influence of some standard printing techniques on the electrical performances of conjugated
polymers is evidenced in order to realise logic devices with these materials.
Schlagworte
Organic electronics; conjugated polymers; organic transistor; printed organic circuits; plastic
electronics; polyaniline; polythiophene; poly(3,3'-dihexyl-2,2':5,2'-terthiophene); printed organic
electronics; impedance spectroscopy.Index
Title ......................................................................................................................................................1
Bibliografische Beschreibung..............................................................................................................2
Index ....................................................................................................................................................3
1 Current situation of information technology (IT)..........................................................................7
1.1 Trend in microelectronics.......................................................................................................8
1.2 Back to macroelectronics........................................................................................................9
1.3 Plastic electronics .................................................................................................................10
1.3.1 Organic light emitting diodes (OLEDs) and organic displays.......................................11
1.3.2 Organic integrated circuits.............................................................................................13
1.4 Economical advantages of printing processes ......................................................................14
2 Operational basics of an organic field effect transistor...............................................................17
2.1 Structure of the FETs............................................................................................................17
2.2 Basic operation of an OFET .................................................................................................18
2.3 Output characteristics modelling of OFETs .........................................................................19
2.3.1 Analytical modelling......................................................................................................20
2.3.2 Numerical modelling .....................................................................................................22
2.3.3 Interface effects..............................................................................................................23
2.3.4 Short-channel effects .....................................................................................................23
2.3.5 Charge carrier mobility ..................................................................................................24
2.3.6 Sub-threshold characteristics .........................................................................................26
2.3.7 Other important parameters for building circuits...........................................................26
3 Conjugated polymers...................................................................................................................28
3.1 Band theory...........................................................................................................................29
3.2 Conjugation ..........................................................................................................................31
3.3 Solitons, polarons, and multipolarons. .................................................................................33
3.4 Supramolecular order and polycrystallinity .........................................................................36
3.5 Inhomogeneous metallic state in conducting polymers........................................................39
3.5.1 Inhomogeneous disorder-induced insulator-metal transition.........................................42
3.5.2 Anderson disorder-induced Insulator-metal transition ..................................................46
3.6 Synthesis...............................................................................................................................48
4 Object of the thesis and chemistry of the conjugated polymers studied .....................................50
4.1 Object of the thesis ...............................................................................................................50
4.2 Conducting polymers............................................................................................................52
4.2.1 Poly(3,4-ethylenedioxythiophene).................................................................................52
Synthesis ..................................................................................................................................53
Conductivity in PEDOT...........................................................................................................54
Electrochemistry of PEDOT ....................................................................................................56
4.2.2 Polyaniline .....................................................................................................................56
Synthesis ..................................................................................................................................58
Influence of organic sulphonic acids .......................................................................................59
Conduction in polyaniline........................................................................................................60
DC conductivity....................................................................................................................63
Reflectance ...........................................................................................................................64
4.3 Semiconducting polymers ....................................................................................................65
4.3.1 Polythiophenes...............................................................................................................65
Polyalkylthiophenes.................................................................................................................66
Synthesis of regioregular head-to-tail PATs from asymmetric coupling of asymmetricIndex
monomers .............................................................................................................................68
Self-assembly and electrical conductivity in HT-PATs .......................................................69
Regioregular polythiophene FETs........................................................................................70
Poly(3,3”-dihexyl-2,2’:5,2”-terthiophene)s .............................................................................71
4.4 Polymeric gate insulators......................................................................................................72
5 Printing and coating ....................................................................................................................74
5.1 Basics of printing and coating techniques ............................................................................74
5.1 Selecting a printing or coating method.................................................................................75
5.1.1 Number of layers............................................................................................................76
5.1.2 Wet layer thickness ........................................................................................................76
5.1.3 Viscosity (and viscoelasticity) .......................................................................................78
5.1.4 Layer accuracy ...............................................................................................................79
5.1.5 Layer support .................................................................................................................79
5.1.6