Physical and Chemical Aspects of Organic Electronics: From Fundamentals to Functioning Devices

Organic Electronics......Page 2
Contents......Page 8
Foreword......Page 22
Acknowledgement......Page 34
List of Contributors......Page 36
Color Plates......Page 48
Part I Industrial Applications......Page 100
1.1 Introduction......Page 102
1.2 What is an Organic Transistor?......Page 103
1.3 How Does an Organic Transistor Work and How Does it Distinguish Itself from a Conventional One?......Page 104
1.4 Basic Logical Integrated Circuits: Ring Oscillators......Page 105
1.5 Complex Organic Circuits: the 64-Bit RFID Tag......Page 108
1.6 Organic CMOS Circuits......Page 109
1.7 Printing Electronics......Page 110
1.8 Application and Future Prospects......Page 112
References......Page 113
2.2 Printed Electronics Market Forecasts......Page 116
2.3 New Products......Page 117
2.3.1 Advantages of Printed Electronics......Page 118
2.3.2 Passive Elements......Page 119
2.3.4 RFID Tags......Page 120
2.4 Printing Considerations......Page 122
2.5 Materials......Page 123
2.5.1 Conductors......Page 124
2.5.2 Dielectrics......Page 126
2.5.3 Semiconductors......Page 127
2.5.3.1 Organic Semiconductors......Page 128
2.5.3.2 Inorganic Semiconductors......Page 129
2.6 Creavis Science-to-Business Approach......Page 130
2.7 Conclusion......Page 131
References......Page 132
Part II Molecular Compounds......Page 134
3.1 Introduction......Page 136
3.2.1.2 2,29,20,2-Tetrafluorophthalocyaninato Zinc(II) (F(4)PcZn)......Page 138
3.2.2 Calculation of Energy Levels......Page 139
3.2.3 Thin Film Preparation and Measurements......Page 140
3.3.1 Synthesis and Molecular Characterisation......Page 141
3.3.2 Thin Evaporated Films of Zinc(II) Phthalocyanines with a Different Degree of Fluorination......Page 143
3.3.3 Growth of F(16)PcZn Thin Films......Page 150
3.3.4 Response to Oxygen from Air......Page 151
3.3.5 Measurements of the Field Effect......Page 154
3.4 Conclusions......Page 156
References......Page 157
4.1 Introduction......Page 160
4.2 Molecular Alignment from Solution Through the Zone-Casting Technique......Page 161
4.3 Solution Processed Donor–Acceptor Copolymer Field-Effect Transistors......Page 166
4.4 Processing of Giant Graphene Molecules by Soft-Landing Mass Spectrometry......Page 168
References......Page 171
5.1 Introduction......Page 174
5.2.1 General Procedures......Page 177
5.2.2 Sample Preparation......Page 178
5.2.3 OFET Device Fabrication......Page 179
5.3.1 Bulk Characterisation......Page 180
5.3.2 Film Characterisation......Page 184
5.3.3 OFET Performance Characteristics......Page 188
5.4 Conclusion......Page 191
References......Page 192
6.1 Introduction......Page 194
6.2.1 Optical Properties......Page 196
6.3 Morphology Studies on Layers of Substituted Xruciforms......Page 198
6.3.1 XRD Studies......Page 199
6.3.2 AFM Studies......Page 201
6.4 OFET Studies......Page 203
6.5 Mobilities from Radiation Induced Conductivity Measurements......Page 206
6.7 Experimental Section......Page 208
References......Page 209
Part III Structural and Morphological Aspects......Page 212
7.1 Introduction......Page 214
7.2.1 Nature of the SAM......Page 216
7.2.2 Seeding Material......Page 218
7.2.3 Stabilising Layer of the Nanoparticles......Page 219
7.2.4 Amplification Method (CVD vs. ELD)......Page 220
7.2.5 Composition of the ELD Bath......Page 224
7.3 Conclusions......Page 231
7.4.4 Stamp Preparation......Page 232
7.4.9 Chemical Vapour Deposition of Gold......Page 233
References......Page 234
8.1 Introduction......Page 238
8.2 Experimental......Page 239
8.3.1.1 X-Ray Diffraction......Page 241
8.3.1.2 Scanning Force Microscopy......Page 244
8.3.2.1 Overview of the ID–VD Characteristics......Page 247
8.3.2.2 Temperature Dependence of the Mobilities......Page 250
8.3.2.3 Detailed Analysis of the Field Effect Mobilities as a Function of VD and VG......Page 251
8.3.3.1 Correlation of the Electrical Transport Properties and the Film Morphology......Page 256
8.3.3.2 Origin of the Structural Defects and Conclusions......Page 257
Acknowledgements......Page 258
References......Page 259
9.1 Introduction......Page 260
9.2 X-Ray Scattering......Page 262
9.3.1 Monolayer Deposition......Page 263
9.3.2 Thin Film Growth and Dynamic Scaling......Page 264
9.3.3 Growth of Organic Molecular Materials......Page 265
9.4.1 Pentacene on Silicon Oxide......Page 266
9.4.2 DIP on Silicon Oxide......Page 268
9.4.3 PTCDA on Ag(111), Cu(111), and Au(111)......Page 272
9.5.1 Metal Capping Layers......Page 274
9.5.2 Insulating Capping Layers......Page 275
9.5.2.2 Encapsulation of Devices......Page 276
9.5.2.3 Aluminium Oxide Capping Layers......Page 277
9.5.2.4 Thermal Stability of Capped Organic Films......Page 279
9.6 Conclusion......Page 282
References......Page 283
10.1 Introduction......Page 288
10.3 X-Ray Grazing-Incidence Diffraction Studies......Page 290
10.4 Structure Determination for LMW Fraction......Page 294
10.5 Temperature-Dependent Measurements......Page 297
10.6 Discussion......Page 301
References......Page 303
11.1 Introduction......Page 306
11.2 Electronic Level Alignment at the Metal/Organics Interface......Page 307
11.3 Structural Properties at the Metal/Organic Interface......Page 310
11.4 General Principles Governing Organic Molecular Beam Deposition (OMBD) on Metal Substrates: Case Studies for Rubrene, Perylene and Pentacene......Page 311
11.4.1 Rubrene Deposition on Au(111)......Page 312
11.4.2 Adsorption-Induced Restructuring of Metal Substrates: Perylene on Cu(110)......Page 313
11.4.3 Organic Molecular Beam Deposition of Pentacene on Clean Metal Surfaces......Page 315
11.5 Organic Molecular Beam Deposition of Perylene......Page 319
11.6 Growth of Other Molecules of Interest for Organic Electronics on Metal Substrates......Page 322
11.7 Growth of Pentacene on Modified Gold Surfaces......Page 323
11.8 Realisation of an “Ideal” Diode-like Organic Electronic Device......Page 325
Acknowledgement......Page 327
References......Page 328
12.1 Introduction......Page 334
12.2 Bonding......Page 337
12.2.1 Bonding: What can be Learned for OFETs?......Page 342
12.3 Structure......Page 345
12.3.1 Structure: What can be Learned for OFETs?......Page 351
12.4 Function......Page 354
Acknowledgements......Page 358
References......Page 359
13.2.1 Sample Preparation and Characterisation......Page 362
13.3.1 Chemistry of Metal/Organic Interfaces......Page 363
13.3.2 Morphological Properties and Indiffusion of Metals at the Interfaces with Organic Semiconductors......Page 369
13.3.3 Assignment of Raman Intensities with DFT Calculations......Page 375
13.4 Conclusion......Page 377
References......Page 378
14.1 Introduction......Page 380
14.1.1 The Present Micro-OFET Concept......Page 381
14.2 Experimental......Page 382
14.3.1.1 Sapphire Substrate......Page 383
14.3.1.2 Growth of DIP on Sapphire......Page 385
14.3.1.3 Contacts – the Au/DIP Interface......Page 388
14.3.1.4 Gate Electrode......Page 393
14.3.1.5 In Situ Device Characterisation......Page 394
14.4 Conclusions......Page 395
References......Page 396
Part IV Device Performance and Characterisation......Page 398
15.2.1 Film Formation on Inert Surfaces......Page 400
15.2.2 Film Formation on Metallic and Conductive Surfaces......Page 404
15.2.3 Mixed Films......Page 405
15.3.1 Mobility and Charge Carrier Density......Page 406
15.3.2 Influence of Trap States and Fixed Interface Charges......Page 408
15.4 Photo Response......Page 410
15.5 Outlook......Page 411
Acknowledgements......Page 412
References......Page 413
16.1 Introduction......Page 416
16.2 Literature Survey......Page 417
16.3.1.1 Short Channel OFET Based on P3HT......Page 419
16.3.1.2 OFET Based on a Modified PPV and with Silanised Gate Oxide......Page 421
16.3.2.1 Quasi-Static CV Curves for a Capacitor with Arylamino-PPV......Page 422
16.3.2.2 Dynamic CV Curves......Page 424
16.4.1 Simulations for the MIS Capacitor......Page 426
16.4.2 Simulations for Thin-Layer OFETs and the Corresponding Capacitor......Page 428
16.5 Equilibrium of Polarons With Doubly Charged States of the Polymer Chain......Page 430
16.5.1.1 Polarons and Bipolarons......Page 431
16.5.1.2 Polarons and Polaron Pairs......Page 432
16.5.2 Polarons, Bipolarons and Polaron Pairs......Page 434
16.5.3 Polarons and General Dipolarons......Page 436
16.6.1.1 Kinetics of Formation and Dissociation......Page 438
16.6.1.2 The Bipolaron Mechanism......Page 439
16.6.2.1 The Kirova–Brazovskii Scenario of Complex Formation......Page 440
16.6.2.2 Slow Ion Capture by an Overcharged Complex......Page 441
16.7 Conclusion......Page 442
References......Page 443
17.1 Introduction......Page 446
17.2 Materials, Device Preparation and Experimental Methods......Page 447
17.3 Unipolar Field-Effect Transistors......Page 451
17.4 Ambipolar Field-Effect Transistors......Page 452
17.5 Charge Carrier Mobility and Threshold Voltage......Page 453
17.6 Film Morphology and Structure......Page 456
17.7 Electronic Structure......Page 458
17.8 Charge Carrier Injection......Page 461
17.9 Ambipolar and Complementary Inverter......Page 464
Acknowledgements......Page 468
References......Page 469
18.1 Introduction......Page 472
18.2.2 Inorganic Dielectrics......Page 473
18.2.3 Polymer Dielectrics......Page 474
18.3 Results and Discussion......Page 475
18.3.1 Inorganic Gate Dielectric Layers......Page 476
18.3.1.1 Thermally Grown Silicon Dioxide......Page 477
18.3.1.2 TEOS Oxide......Page 479
18.3.1.3 Silicon Nitride......Page 481
18.3.1.4 Low-Temperature Oxide: LTO......Page 482
18.3.1.5 PECVD......Page 483
18.3.1.6 Ta(5)O(2)......Page 484
18.3.1.7 Conclusion......Page 485
18.3.2 Polymer Dielectrics......Page 486
18.3.2.1 Bectron® Varnish......Page 488
18.3.2.2 High-k Resist......Page 489
18.3.2.3 OFET on Foil Substrates......Page 490
18.3.2.4 Conclusion......Page 491
18.4 Degradation......Page 492
18.5 Conclusion......Page 497
References......Page 498
19.1 Introduction......Page 500
19.2.1 Organic Semiconductors......Page 501
19.2.2 Thin Film Deposition......Page 502
19.2.3 Radiotracer Measurements......Page 503
19.3.1 Radiotracer Measurements......Page 504
19.3.2 Correlation Between Metal Diffusion and Device Properties of OFETs......Page 515
19.3.3 Teflon-Based Electret Layers for Threshold Voltage Tuning......Page 520
19.4 Conclusions......Page 523
References......Page 524
20.1 Introduction......Page 526
20.2 Device Geometries and Sample Preparation......Page 528
20.3.2 Mobility Estimates......Page 530
20.3.3 Two-Dimensional Device Simulation......Page 532
20.3.4 Charge Transient Spectroscopy......Page 535
20.4.1 Electrical Characterisation In Situ......Page 537
20.4.2 Potentiometry Measurements Ex Situ......Page 538
20.4.3 Charge Transient Spectroscopy......Page 540
20.5 Conclusion......Page 541
References......Page 542
21.1 Introduction......Page 544
21.2.1.1 PEEM......Page 546
21.2.2.1 Interface Characterisation......Page 547
21.2.2.2 Electrical Characterisation (CV, IV)......Page 548
21.3.1.1 PEEM......Page 549
21.3.1.2 SKPM......Page 553
21.3.2.1 Interface Characterisation......Page 555
21.3.2.2 Electrical Characterisation of MFIS Capacitors (CV Measurements)......Page 559
21.3.2.3 Ferroelectric OFET......Page 561
21.4 Summary and Conclusions......Page 564
References......Page 566
22.1 Introduction......Page 568
22.2.1 Geometries......Page 570
22.2.2 Sample Preparation......Page 571
22.3.1 Unsubstituted Oligothiophenes......Page 572
22.3.2 Substituted Oligothiophenes......Page 573
22.3.3 Polythiophenes......Page 574
22.4.1 Influence of the Electrode Material......Page 575
22.4.2 Influence of the Insulator Thickness......Page 577
22.5.1 Semiconductor Related Performance......Page 578
22.5.2 Tuning the Contact Resistance......Page 580
22.6 Influence of the Semiconductor Thickness......Page 582
22.6.1 Large Channels......Page 583
22.6.2 Sub-micron Channels......Page 584
22.7.1 Theoretical Considerations......Page 587
22.7.2 Experimental Results......Page 590
22.8 Summary......Page 593
References......Page 594
23.1 Introduction......Page 598
23.2.2 Characterisation......Page 599
23.3.1 Influence of Formation Current Density......Page 600
23.3.2 Influence of the Formation Voltage......Page 603
23.3.3 Influence of Anodisation Time......Page 605
23.3.4 Influence of Surface Roughness......Page 607
23.3.5 Barrier Aluminium Oxide Films as Gate Dielectrics for Organic Transistors......Page 608
23.4 Conclusion......Page 609
References......Page 610
24.1 Introduction......Page 612
24.2.1 Device Structure......Page 616
24.2.2 Device Measurement......Page 617
24.3 Results and Discussion......Page 618
24.4 Conclusion......Page 634
References......Page 636
25.1 Introduction......Page 638
25.2.2 Purification......Page 640
25.2.2.1 Purification by Zone Refinement......Page 641
25.2.2.3 Control of Chemical Purity......Page 642
25.2.3 Crystal Growth......Page 643
25.2.4 Field-Effect-Transistor Fabrication......Page 645
25.2.4.1 Gate Insulator Thickness......Page 646
25.3.1 Tetracene Crystals: Surface Versus Bulk Transport......Page 647
25.3.2 Diindenoperylene Crystals: Structural Impact on Transport......Page 653
25.4 Conclusion......Page 660
References......Page 661
Part V Novel Devices......Page 664
26.1 Introduction......Page 666
26.2.1 Physical and Electronic Structure......Page 667
26.2.2 Field-Effect Transistors Based on Single SWCNTs......Page 668
26.2.3 CNT-FETs Based on Electrochemical Field-Effect......Page 671
26.2.4 Role of Capacitances......Page 672
26.3.1 Motivation and Strategies......Page 674
26.3.2 Chemically Modified Devices......Page 675
26.3.3 Electrochemical Functionalisation......Page 676
26.3.4 Selective Electrochemical Functionalisation......Page 678
26.3.5 Chemical Doping......Page 682
26.4 Device Characterisation of CNT-FETs......Page 684
26.4.1.3 Sub-Threshold Swing......Page 685
26.4.3 Scanning Photocurrent Microscopy......Page 686
26.5 Future Perspectives......Page 688
References......Page 689
27.1 Introduction......Page 694
27.2.1 Device Preparation......Page 696
27.2.2 Contact Size......Page 697
27.2.3 Oxide Interlayer Between Top Contact and Cu(TCNQ)......Page 698
27.2.4 Reversible Loss of Bistability in Oxygen-Free Ambience......Page 699
27.2.5 Tip Contacts of Various Metals to Cu(TCNQ)......Page 700
27.2.6 Planar Device Structure......Page 703
27.2.7 Localisation of Switching Region......Page 704
27.3 Discussion and Conclusion......Page 708
References......Page 711
28.1 Introduction......Page 712
28.2 Concepts and Progress of Spintronics......Page 713
28.3 Organic Semiconductors in Spintronics Applications......Page 715
28.4 OFET Concept for Spin-Polarised Transport......Page 716
28.5 Experimental Realisation......Page 719
28.6 Results and Discussion......Page 720
28.7 Conclusion......Page 725
References......Page 726
Index......Page 728