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This book addresses the physical mechanisms involved in the characteristic electrical properties and the geometrical structures that are observed from dipolar monolayers composed of organic molecules by using dielectric physics, electrostatics, the physics of liquid crystal, and soft matter physics. The orientational order parameters, introduced to quantify the orientational structures of monolayers, guide us towards this goal. Dielectric polarizations are spontaneously generated from monolayers because of their orientational structures, and electrostatic energies due to these dielectric polarizations play a key role in forming the geometrical structures that are observed from monolayers. Free energy minimization is a powerful tool to understand the physical mechanisms that stabilize these geometrical structures because of the soft matter nature of monolayers. The approach using mathematical differential geometry method makes this book unique among the literatures of monolayers.

This reference text provides a comprehensive and concise overview of organic electronics, covering both the theoretical background physics and the physics of the materials and devices behind the technology. The book covers the electrical properties, structure of matter and physics of one-dimensional solids with their characteristic instabilities. A range of materials, including crystalline organic conductors and superconductors, organic semiconductors for organic electronics (small molecules, and polymers), and self-assembled molecular arrangements for molecular scale devices are discussed, alongside case studies, worked examples and pedagogical problems. This book provides an invaluable reference for graduate and senior undergraduate students, researchers, and engineers with a minimal background in condensed matter physics.

This reference work on Spin in Organics contains four volumes dedicated to spin injection, spin transport, spin pumping, organic magnetic field effect, and molecular spintronics. The field of Organic Spintronics has accelerated and matured in the last dozen years with the realization of an organic spin-valve (in 2004) and magneto-resistance and magneto-electroluminescence in organic optoelectronic devices (2006).The book series is comprehensive in that it summarizes all aspects of Organic Spintronics to date. The first two volumes deal with spin injection, spin transport, spin manipulation and spin pumping into organic semiconductors. The main device that is thoroughly discussed here is the organic spin-valve, where spinterface states at the interface between the organic semiconductor and the ferromagnetic (FM) electrode has been the focus of many chapters. An interesting emerging subject is the role of chirality in the organic layer of the device. A relatively new method of achieving spin aligned carriers in organic semiconductors is spin pumping, where magnons in the FM substrate generate spin aligned carriers in the organic layer at the FM/organic interface.The third volume deals mainly with magnetic field effect in organic devices. Several spin-mixture processes that lead to magnetic field effect in devices and films are thoroughly discussed, such as hyperfine interaction, direct spin-orbit coupling, indirect spin-orbit coupling via Δg, triplet-triplet annihilation, and thermal spin alignment. The similarity between the magnetic field effect obtained in optoelectronic devices based on organic semiconductors and the novel hybrid organic-inorganic semiconductors is also a subject of intense interest. The fourth volume deals with spin in molecular films and devices. It includes thorough discussion of spin exchange interaction that leads to organic ferromagnets, as well as manifestation of various spin interactions in thin molecular films and devices.

This book focuses on the microscopic understanding of the function of organic semiconductors. By tracing the link between their morphological structure and electronic properties across multiple scales, it represents an important advance in this direction. Organic semiconductors are materials at the interface between hard and soft matter: they combine structural variability, processibility and mechanical flexibility with the ability to efficiently transport charge and energy. This unique set of properties makes them a promising class of materials for electronic devices, including organic solar cells and light-emitting diodes. Understanding their function at the microscopic scale – the goal of this work – is a prerequisite for the rational design and optimization of the underlying materials. Based on new multiscale simulation protocols, the book studies the complex interplay between molecular architecture, supramolecular organization and electronic structure in order to reveal why some materials perform well – and why others do not. In particular, by examining the long-range effects that interrelate microscopic states and mesoscopic structure in these materials, the book provides qualitative and quantitative insights into e.g. the charge-generation process, which also serve as a basis for new optimization strategies.

The book covers a variety of studies of organic semiconductors, from fundamental electronic states to device applications, including theoretical studies. Furthermore, innovative experimental techniques, e.g., ultrahigh sensitivity photoelectron spectroscopy, photoelectron yield spectroscopy, spin-resolved scanning tunneling microscopy (STM), and a material processing method with optical-vortex and polarization-vortex lasers, are introduced. As this book is intended to serve as a textbook for a graduate level course or as reference material for researchers in organic electronics and nanoscience from electronic states, fundamental science that is necessary to understand the research is described. It does not duplicate the books already written on organic electronics, but focuses mainly on electronic properties that arise from the nature of organic semiconductors (molecular solids). The new experimental methods introduced in this book are applicable to various materials (e.g., metals, inorganic and organic materials). Thus the book is also useful for experts working in physics, chemistry, and related engineering and industrial fields.

This book is an introductory text for graduate students, researchers in industries, and those who are just beginning to work on organic electronics materials, devices and their applications. The book includes mainly fundamental principles and theories for understanding organic electronics materials and devices, but also provides information about state-of-the-art technologies, applications and future prospects. These topics encompass physics for organic transistors, structure control technologies of polymer semiconductors, nanomaterials electronics, organic solar cells, organic electroluminescence, liquid semiconductors and dynamics for excitation, among others. This book will help researchers to be able to contribute to society with the technologies and science of organic electronics materials in the future.

This is an exciting stage in the development of organic electronics. It is no longer an area of purely academic interest as increasingly real applications are being developed, some of which are beginning to come on-stream. Areas that have already been commercially developed or which are under intensive development include organic light emitting diodes (for flat panel displays and solid state lighting), organic photovoltaic cells, organic thin film transistors (for smart tags and flat panel displays) and sensors.Within the family of organic electronic materials, liquid crystals are relative newcomers. The first electronically conducting liquid crystals were reported in 1988 but already a substantial literature has developed. The advantage of liquid crystalline semiconductors is that they have the easy processability of amorphous and polymeric semiconductors but they usually have higher charge carrier mobilities. Their mobilities do not reach the levels seen in crystalline organics but they circumvent all of the difficult issues of controlling crystal growth and morphology. Liquid crystals self-organise, they can be aligned by fields and surface forces and, because of their fluid nature, defects in liquid crystal structures readily self-heal.With these matters in mind this is an opportune moment to bring together a volume on the subject of ‘Liquid Crystalline Semiconductors'. The field is already too large to cover in a comprehensive manner so the aim has been to bring together contributions from leading researchers which cover the main areas of the chemistry (synthesis and structure/function relationships), physics (charge transport mechanisms and optical properties) and potential applications in photovoltaics, organic light emitting diodes (OLEDs) and organic field-effect transistors (OFETs).This book will provide a useful introduction to the field for those in both industry and academia and it is hoped that it will help to stimulate future developments.

In recent years, ever more electronic devices have started to exploit the advantages of organic semiconductors. The work reported in this thesis focuses on analyzing theoretically the energy level alignment of different metal/organic interfaces, necessary to tailor devices with good performance. Traditional methods based on density functional theory (DFT), are not appropriate for analyzing them because they underestimate the organic energy gap and fail to correctly describe the van der Waals forces.Since the size of these systems prohibits the use of more accurate methods, corrections to those DFT drawbacks are desirable. In this work a combination of a standard DFT calculation with the inclusion of the charging energy (U) of the molecule, calculated from first principles, is presented. Regarding the dispersion forces, incorrect long range interaction is substituted by a van der Waals potential. With these corrections, the C60, benzene, pentacene, TTF and TCNQ/Au(111) interfaces are analyzed, both for single molecules and for a monolayer. The results validate the induced density of interface states model.

Mechanism of charge transport in organic solids has been an issue of intensive interests and debates for over 50 years, not only because of the applications in printing electronics, but also because of the great challenges in understanding the electronic processes in complex systems. With the fast developments of both electronic structure theory and the computational technology, the dream of predicting the charge mobility is now gradually becoming a reality. This volume describes recent progresses in Prof. Shuai's group in developing computational tools to assess the intrinsic carrier mobility for organic and carbon materials at the first-principles level. According to the electron-phonon coupling strength, the charge transport mechanism is classified into three different categories, namely, the localized hopping model, the extended band model, and the polaron model. For each of them, a corresponding theoretical approach is developed and implemented into typical examples.

Major development efforts in organic materials research has grown for an array of applications. Organic spintronics, in particular, has flourished in the area of organic magneto-transport. Reflecting the main avenues of advancement in this arena, this volume explores spin injection and manipulation in organic spin valves, the magnetic field effect in organic light-emitting diodes (OLEDs), the spin transport effect in relation to spin manipulation, organic magnets as spin injection electrodes in organic spintronics devices, the coherent control of spins in organic devices using the technique of electronically detected magnetic resonance, and the possibility of using organic spin valves as sensors.

Dear Readers, Since the ground-breaking, Nobel-prize crowned work of Heeger, MacDiarmid, and Shirakawa on molecularly doped polymers and polymers with an alternating bonding structure at the end of the 1970s, the academic and industrial research on hydrocarbon-based semiconducting materials and devices has made encouraging progress. The strengths of semiconducting polymers are currently mainly unfolding in cheap and easily assembled thin?lm transistors, light emitting diodes, and organic solar cells. The use of so-called “plastic chips” ranges from lightweight, portable devices over large-area applications to gadgets demanding a degree of mechanical?exibility, which would overstress conventionaldevices based on inorganic,perfect crystals. The?eld of organic electronics has evolved quite dynamically during the last few years; thus consumer electronics based on molecular semiconductors has gained suf?cient market attractiveness to be launched by the major manufacturers in the recent past. Nonetheless, the numerous challenges related to organic device physics and the physics of ordered and disordered molecular solids are still the subjects of a cont- uing lively debate. The future of organic microelectronics will unavoidably lead to new devi- physical insights and hence to novel compounds and device architectures of - hanced complexity. Thus, the early evolution of predictive models and precise, computationally effective simulation tools for computer-aided analysis and design of promising device prototypes will be of crucial importance.

Organic molecules are currently being investigated with regard to their application as active components in semiconductor devices. Whereas devices containing organic molecules for the generation of light - organic light emitting diodes (OLED) - have already reached the market (they e.g. display information on mobile phones), transistors where organic molecules are used to actively control currents and voltages are still in the development stage. In this book the principle problems related to using organic materials as semiconductors and to construct functioning devices will be addressed. A particular emphasis will be put on the difference between inorganic semiconductors such as Si, Ge and GaAs and organic semiconductors (OSC). The special properties of such soft matter require particular approaches for processing characterization and device implementation, which are quite different from the approach used for conventional semiconductors.

This book provides the first comprehensive overview of fabrication, fundamental properties and applications of a new class of nanoscaled organic materials which holds huge promise for future submicron-sized photonics and optoelectronics. By controlled self-assembled growth on single crystal surfaces, fiber-like structures are fabricated with macroscopic lengths up to millimeter size but mesoscopic widths of mere hundreds of nanometers and nanoscopic heights of several ten nanometers. The extraordinary beauty of these new structures is that they are quasi single crystalline, providing superior optical and electronic properties, and that their properties can be freely tailored via functionalization of their organic building blocks.