Organic Electronics: Emerging Concepts and Technology -- Contents -- Preface -- List of Contributors -- 1 Nanoparticles Based on p-Conjugated Polymers and Oligomers for Optoelectronic, Imaging, and Sensing Applications: The Illustrative Example of Fluorene-Based Polymers and Oligomers -- 1.1 Introduction -- 1.2 Nanoparticles Based on Fluorene Polymers -- 1.2.1 Optoelectronic Applications -- 1.2.1.1 Characterization of Nanoparticles -- 1.2.1.2 Nanoparticle Film Fabrication and Characterization -- 1.2.1.3 OLEDs -- 1.2.1.4 Solar Cell Applications -- 1.2.2 Imaging and Sensing Applications -- 1.2.2.1 Characterization of Nanoparticles -- 1.2.2.2 Biosensing -- 1.2.2.3 Bioimaging -- 1.3 Nanoparticles Based on Fluorene Oligomer -- 1.3.1 Characterization -- 1.3.2 Nanoparticles for Sensing and Imaging -- 1.4 Conclusions and Perspectives -- References -- 2 Conducting Polymers to Control and Monitor Cells -- 2.1 Introduction -- 2.2 Conducting Polymers for Biological Applications -- 2.2.1 Unique Benefits of Conducting Polymers -- 2.2.2 Biocompatibility of Conducting Polymers -- 2.2.3 Electrochemical Properties and Tools -- 2.3 Conducting Polymers to Control Cells -- 2.3.1 Establishing Conducting Polymers as Cell Culture Environments -- 2.3.2 Optimizing Conducting Polymers for Cell Culture -- 2.3.3 Controlling Cell Adhesion via Redox State -- 2.3.3.1 Redox Switches -- 2.3.3.2 Redox Gradients -- 2.3.3.3 Protein Characterization as a Function of Redox State -- 2.3.4 Direct Patterning of Proteins to Control Cell Adhesion -- 2.3.5 Controlling Cell Growth and Development -- 2.3.5.1 Electrical Stimulation to Promote Neurite Formation and Extension -- 2.3.5.2 Electrical Stimulation to Promote Muscle Cell Proliferation and Differentiation -- 2.3.5.3 Alignment Control via Topographical Cues -- 2.3.5.4 Incorporation of Biomolecules to Control Differentiation.

2.3.6 Organic Electronic Ion Pumps -- 2.3.7 On-Demand Cell Release -- 2.3.8 Conducting Polymer Actuators -- 2.3.9 Optoelectronic Control of Cell Behavior -- 2.4 Conducting Polymers to Monitor Cells -- 2.4.1 Conducting Polymers to Monitor Neuronal Function -- 2.4.1.1 Conducting Polymer Electrodes -- 2.4.1.2 Transistors -- 2.4.2 Conducting Polymers to Monitor Behavior of Nonelectrically Active Cells -- 2.5 Conclusions -- References -- 3 Medical Applications of Organic Bioelectronics -- 3.1 Introduction -- 3.2 Regenerative Medicine and Biomedical Devices -- 3.2.1 Scaffolds, Signaling Interfaces, and Surfaces for Novel Biomedical Applications -- 3.2.1.1 Scaffolds and Surface Modulation -- 3.2.1.2 Biomolecule Presenting Surfaces -- 3.2.1.3 Degradable Surfaces for Biomedical Applications -- 3.2.1.4 Controlled Substance Release -- 3.2.2 Prosthetics and Medical Devices -- 3.2.2.1 Organic Bioelectronics as Actuators -- 3.2.2.2 Neuroprosthetics -- 3.3 Organic Electronics in Biomolecular Sensing and Diagnostic Applications -- 3.3.1 Organic Electronics as Biomolecule Sensors: A Technological Overview -- 3.3.2 Small-Molecule and Biological Metabolite Sensing -- 3.3.3 Immunosensors -- 3.3.4 DNA Sensing -- 3.3.5 Medical Diagnosis and the Electronic Nose -- 3.4 Concluding Remarks -- References -- 4 A Hybrid Ionic-Electronic Conductor: Melanin, the First Organic Amorphous Semiconductor? -- 4.1 Introduction and Background -- 4.2 Physical and Optical Properties of Melanin and the Transport Physics of Disordered Semiconductors -- 4.3 The Hydration Dependence of Melanin Conductivity -- 4.4 Muon Spin Relaxation Spectroscopy and Electron Paramagnetic Resonance -- 4.5 Transport Model for Electrical Conduction and Photoconduction in Melanin -- 4.6 Bioelectronics, Hybrid Devices, and Future Perspectives -- References.

5 Eumelanin: An Old Natural Pigment and a New Material for Organic Electronics - Chemical, Physical, and Structural Properties in Relation to Potential Applications -- 5.1 Introduction: The "Nature-Inspired" -- 5.2 Natural Melanins -- 5.2.1 Overview -- 5.2.2 Distribution and Isolation of Natural Eumelanin -- 5.2.3 Melanogenesis: From Understanding the In Vivo Path to In Vitro Pigment Preparation -- 5.3 Synthetic Melanins -- 5.3.1 Overview -- 5.3.2 Oxidative Polymerization of 5,6-Dihydroxyindole(s) -- 5.4 Chemical-Physical Properties and Structure-Property Correlation -- 5.4.1 Stability against Acids and Bases -- 5.4.2 Molecular Weight -- 5.4.3 Hydration, Aggregation, and Supramolecular Organization -- 5.4.4 Light Absorption and Scattering -- 5.4.5 Metal Chelation -- 5.4.6 Redox State -- 5.4.7 Autoxidation -- 5.4.8 Bleaching -- 5.4.9 NMR Spectroscopy -- 5.4.10 EPR Spectroscopy -- 5.5 Thin Film Fabrication -- 5.6 Melanin Hybrid Materials -- 5.7 Conclusions -- References -- 6 New Materials for Transparent Electrodes -- 6.1 Introduction -- 6.1.1 Indium Tin Oxide -- 6.1.2 Optoelectronic Characteristics -- 6.1.2.1 The Influence of Sheet Resistance -- 6.1.2.2 Optical Transparency -- 6.1.2.3 Transmittance Versus Sheet Resistance Trade-off Characteristics -- 6.1.2.4 Work Function -- 6.2 Emergent Electrode Materials -- 6.2.1 Graphene -- 6.2.1.1 Fabrication -- 6.2.1.2 Outlook -- 6.2.2 Carbon Nanotubes -- 6.2.2.1 Structure -- 6.2.2.2 Networks -- 6.2.2.3 Film Fabrication -- 6.2.2.4 Improving Performance -- 6.2.3 Metal Nanowires -- 6.2.3.1 Silver Nanowires -- 6.2.3.2 Alternative Metal Nanowires -- 6.3 Conclusions -- References -- 7 Ionic Carriers in Polymer Light-Emitting and Photovoltaic Devices -- 7.1 Polymer Light-Emitting Electrochemical Cells -- 7.2 Ionic Carriers -- 7.3 Fixed Ionic Carriers -- 7.4 Fixed Junction LEC-Based Photovoltaic Devices.

7.5 Conclusions -- References -- 8 Recent Trends in Light-Emitting Organic Field-Effect Transistors -- 8.1 Introduction -- 8.2 Working Principle -- 8.2.1 Unipolar LEFETs -- 8.2.2 Ambipolar LEFETs -- 8.3 Recent Trends and Developments -- 8.3.1 Heterojunction Light-Emitting FETs -- 8.3.2 Single-Crystal Light-Emitting FETs -- 8.3.3 Carbon Nanotube Light-Emitting FETs -- 8.4 Conclusions -- References -- 9 Toward Electrolyte-Gated Organic Light-Emitting Transistors: Advances and Challenges -- 9.1 Introduction -- 9.2 Electrolyte-Gated Organic Transistors -- 9.3 Electrolytes Employed in Electrolyte-Gated Organic Transistors -- 9.4 Preliminary Results and Challenges in Electrolyte-Gated Organic Light-Emitting Transistors -- 9.5 Relevant Questions and Perspectives in the Field of EG-OLETs -- References -- 10 Photophysical and Photoconductive Properties of Novel Organic Semiconductors -- 10.1 Introduction -- 10.2 Overview of Materials -- 10.2.1 Benzothiophene, Anthradithiophene, and Longer Heteroacene Derivatives -- 10.2.2 Pentacene and Hexacene Derivatives -- 10.2.3 Indenofluorene Derivatives -- 10.3 Optical and Photoluminescent Properties of Molecules in Solutions and in Host Matrices -- 10.4 Aggregation and Its Effect on Optoelectronic Properties -- 10.4.1 J-Versus H-Aggregate Formation -- 10.4.2 Example of Aggregation: Disordered H-Aggregates in ADT-TES-F Films -- 10.4.2.1 Aggregate Formation: Optical and Photoluminescent Properties -- 10.4.2.2 Aggregate Formation: Photoconductive Properties -- 10.4.2.3 ADT-TES-F Aggregates: Identification and Properties -- 10.4.3 Effects of Molecular Packing on Spectra -- 10.4.3.1 Molecular Structure and Solid-State Packing -- 10.4.3.2 Film Morphology and Spectra -- 10.5 (Photo)Conductive Properties of Pristine Materials -- 10.5.1 Ultrafast Photophysics and Charge Transport on Picosecond Timescales.

10.5.2 Charge Transport on Nanosecond and Longer Timescales -- 10.5.3 Dark Current and cw Photocurrent -- 10.6 Donor-Acceptor Composites -- 10.6.1 Donor-Acceptor Interactions: FRET versus Exciplex Formation -- 10.6.2 Donor-Acceptor Interactions Depending on the Donor-Acceptor LUMO Energies Offset, Donor and Acceptor Separation, and Film Morphology -- 10.6.2.1 Effects on the Photoluminescence -- 10.6.2.2 Effects on the Photocurrent -- 10.7 Summary and Outlook -- References -- 11 Engineering Active Materials for Polymer-Based Organic Photovoltaics -- 11.1 Introduction -- 11.2 Device Architectures and Operating Principles -- 11.2.1 Device Architectures -- 11.2.1.1 Active Layer -- 11.2.1.2 Contacts -- 11.2.2 Energetics of Charge Generation in OPV Devices -- 11.3 Bandgap Engineering: Low-Bandgap Polymers -- 11.4 Molecular Acceptor Materials for OPV -- 11.4.1 Morphology -- 11.4.2 Electron Affinity -- 11.4.3 Stabilization of Reduced Acceptor -- 11.4.4 Complementary Light Absorption -- 11.5 Summary -- References -- 12 Single-Crystal Organic Field-Effect Transistors -- 12.1 Introduction -- 12.2 Single-Crystal Growth -- 12.3 MISFET -- 12.4 Schottky Diode and MESFET -- 12.5 Ambipolar Transistor -- 12.6 Light-Emitting Ambipolar Transistor -- 12.7 Electric Double-Layer Transistor -- 12.8 Conclusion -- References -- 13 Large-Area Organic Electronics: Inkjet Printing and Spray Coating Techniques -- 13.1 Introduction -- 13.2 Organic Electronic Devices - Operation Principles -- 13.3 Materials for Organic Large-Area Electronics -- 13.4 Manufacturing Processes for Large-Area Electronics -- 13.4.1 Organic Devices Fabricated by Printing Methods -- 13.4.1.1 Soft Lithography -- 13.4.1.2 Inkjet Printing -- 13.4.2 Spray Deposition for Organic Large-Area Electronics -- 13.4.2.1 Motivation and Technical Aspects for Spray Deposition.

13.4.2.2 Top Electrodes Deposited by Spray Coating.