Systematic summary of advances in developing effective methodologies of interface engineering in organic field-effect transistors, from models to experimental techniques
Interface Engineering in Organic Field-Effect Transistors covers the state of the art in organic field-effect transistors and reviews charge transport at the interfaces, device design concepts, and device fabrication processes, and gives an outlook on the development of future optoelectronic devices.
This book starts with an overview of the commonly adopted methods to obtain various semiconductor/semiconductor interfaces and charge transport mechanisms at these heterogeneous interfaces. Then, it covers the modification at the semiconductor/electrode interfaces, through which to tune the work function of electrodes as well as reveal charge injection mechanisms at the interfaces.
Charge transport physics at the semiconductor/dielectric interface is discussed in detail. The book describes the remarkable effect of SAM modification on the semiconductor film morphology and thus the electrical performance. In particular, valuable analyses of charge trapping/detrapping engineering at the interface to realize new functions are summarized.
Finally, the sensing mechanisms that occur at the semiconductor/environment interfaces of OFETs and the unique detection methods capable of interfacing organic electronics with biology are discussed.
Specific sample topics covered in Interface Engineering in Organic Field-Effect Transistors include: - Noncovalent modification methods, charge insertion layer at the electrode surface, dielectric surface passivation methods, and covalent modification methods - Charge transport mechanism in bulk semiconductors, influence of additives on materials’ nucleation and morphology, solvent additives, and nucleation agents - Nanoconfinement effect, enhancing the performance through semiconductor heterojunctions, planar bilayer heterostructure, ambipolar charge-transfer complex, and supramolecular arrangement of heterojunctions - Dielectric effect in OFETs, dielectric modification to tune semiconductor morphology, surface energy control, microstructure design, solution shearing, eliminating interfacial traps, and SAM/SiO2 dielectrics
A timely resource providing the latest developments in the field and emphasizing new insights for building reliable organic electronic devices, Interface Engineering in Organic Field-Effect Transistors is essential for researchers, scientists, and other interface-related professionals in the fields of organic electronics, nanoelectronics, surface science, solar cells, and sensors.
Table of Contents
Preface ix
Author Biographies xi
List of Acronyms and Abbreviations xiii
1 Introduction 1
1.1 Different Interfaces in OFETs 1
1.2 Brief Historic Overview of Interface Engineering in OFETs 3
1.3 Scope of the Book 3
2 Interfacial Modification Methods 7
2.1 Noncovalent Modification Methods 7
2.1.1 Charge Insertion Layer at the Electrode Surface 7
2.1.2 Dielectric Surface Passivation Methods 9
2.2 Covalent Modification Methods 12
2.2.1 SAM Modification of Electrodes 12
2.2.2 SAM Modification of Dielectrics 12
2.2.2.1 SAM/SiO2 Dielectrics 14
2.2.2.2 SAM/High-k Dielectrics 14
2.2.2.3 Self-Assembled Monolayer Field-Effect Transistors (SAMFETs) 28
2.3 Efforts in Developing New Methods 31
3 Semiconductor/Semiconductor Interface 33
3.1 Influence of Additives on a Material’s Nucleation and Morphology 37
3.1.1 Solvent Additives 37
3.1.2 Nucleating Agents 41
3.1.3 Template-Mediated Crystallization 43
3.1.4 Blending with Insulating Polymers 45
3.1.5 Blending with Polymer Elastomer: Nanoconfinement Effect 50
3.2 Enhancing the Performance Through Semiconductor Heterojunctions 55
3.2.1 Planar Bilayer Heterostructures 57
3.2.2 Molecular-Level Heterojunction 61
3.2.3 Supramolecular Arrangement of the Heterojunctions 64
3.3 Integrating Molecular Functionalities into Electrical Circuits 69
3.3.1 Charge-Trapping-Induced Memory Effect 69
3.3.2 Photochromism-Induced Switching Effect 72
4 Semiconductor/Electrode Interface 77
4.1 Work Function Tuning for Better Contact 79
4.1.1 SAM Modification 80
4.1.2 Charge Insertion Layer Modification 84
4.1.3 Polymer-Based Electrodes 89
4.1.4 Carbon Nanomaterial-Based Electrodes 92
4.1.5 Covalent Bond Formation at the Molecular Level 97
4.2 Installing Switching Effects at Semiconductor/Electrode Interface 100
5 Semiconductor/Dielectric Interface 103
5.1 Dielectric Modification to Tune Semiconductor Morphology 105
5.1.1 Dielectric Surface Energy Control 106
5.1.1.1 Modify with SAM 106
5.1.1.2 Surface Modification with Polymers 112
5.1.2 Dielectric Microstructure Design 113
5.1.2.1 Roughness Effect 114
5.1.2.2 Nano-fabrication Created Microstructure 116
5.1.2.3 Self-assembled Morphology of Dielectric 118
5.2 Eliminating Interfacial Traps 120
5.2.1 Dielectric Surface Passivation (Treatment) Methods 121
5.2.1.1 Polymer Encapsulation of Dielectrics 122
5.2.1.2 Gap Dielectrics 124
5.2.2 SAM/SiO2 Dielectrics 126
5.2.2.1 Provide Efficient Insulating Barrier Height 127
5.2.2.2 Control Surface Polarity and Carrier Density 128
5.2.3 SAM/High-k Dielectrics 131
5.2.3.1 Fundamentals of SAM-Modified High-k Dielectrics 132
5.2.3.2 SAM/High-k Hybrid Dielectrics for Flexible Substrate 134
5.2.4 Self-assembled Monolayer Field-Effect Transistors (SAMFETs) 137
5.2.4.1 Molecule Design for SAMFETs 137
5.2.4.2 Morphology Control of SAMFET 139
5.3 Integrating New Functionalities 141
5.3.1 Photoresponsive Dielectrics 142
5.3.2 Other External Stimuli-Responsive Dielectrics 144
5.3.2.1 Pressure Sensor 145
5.3.2.2 Thermal Sensor 147
5.3.2.3 Magnetic Sensor 147
5.3.2.4 Multifunctional Sensor 148
5.3.3 Integrating Memory Effect at the Dielectrics 148
6 Semiconductor/Environment Interface 155
6.1 Device Optimization to Improve Sensing Performance 156
6.1.1 Monolayer Functionalization 156
6.1.2 Bilayer Heterojunction Approach 158
6.1.3 Remote Floating Gate 159
6.2 OECT-Based and EGOFET-Based Sensors 160
7 Interfacing Organic Electronics with Biology 165
7.1 Integration of OFETs/OECTs with Nonelectrogenic Cells 166
7.2 Integration of Flexible Bioelectronics with Electrogenic Cells 170
7.3 Light/Cell/Device Interfaces 174
8 Concluding Remarks and Outlook 179
8.1 New Challenges in Molecular Design 179
8.2 High-Quality OSC Films: Self-Assembly Control 180
8.3 High-Performance Scalable Flexible Optoelectronics 180
8.4 Exploration of Novel Structures: Organic/2D Heterostructures and Vertical Structures 181
8.5 Instability: Stability in Aqueous Media and Thermal Stability in Hygienic Applications 181
8.6 Multifunctional Sensor Systems 183
References 185
Index 251
