This book systematically introduces the most important aspects of organic semiconductor heterojunctions, including the basic concepts and electrical properties. It comprehensively discusses the application of organic semiconductor heterojunctions as charge injectors and charge generation layers in organic light-emitting diodes (OLEDs). Semiconductor heterojunctions are the basis for constructing high-performance optoelectronic devices. In recent decades, organic semiconductors have been increasingly used to fabricate heterojunction devices, especially in OLEDs, and the subject has attracted a great deal of attention and evoked many new phenomena and interpretations in the field. This important application is based on the low dielectric constant of organic semiconductors and the weak non-covalent electronic interactions between them, which means that they easily form accumulation heterojunctions. As we know, the accumulation-type space charge region is highly conductive, which is an important property for highly efficient charge generation in their application as charge injector and charge generation layer in OLEDs. This book serves as a valuable reference for researchers and as a textbook for graduate students focusing on the study and development of OLED for display and lighting.

It is well known that most important electronic devices use Schottky junctions and heterojunctions. Unfortunately there is not an advanced book introducing heterojunctions systematically. Introduction to Organic Semiconductor Heterojunctions fills the gap. In this book, the authors provide a comprehensive discussion and systematic introduction on the state-of-the-art technologies as well as application of organic semiconductor heterojunctions. First book to systematically introduce organic heterojunctions Arms readers with theoretical, experimental and applied aspects of organic heterojunctions The Chinese edition of the book is part of the Chinese Academy of Sciences’ Distinguished Young Scholar Scientific Book Series Introduction to Organic Semiconductor Heterojunctions is an ideal and valued reference for researchers and graduate students focusing on organic thin film devices like organic light-emitting diodes (OLEDs), organic photovoltaic (OPV) cells, and organic field-effect transistors (OFETs). Instructors can use the book as a supplementary text for a semiconductor physics or organic electronics course, giving students a better feel for the application of organic thin film devices.

Optoelectronic Organic-Inorganic Semiconductor Heterojunctions summarizes advances in the development of organic-inorganic semiconductor heterojunctions, points out challenges and possible solutions for material/device design, and evaluates prospects for commercial applications. Introduces the concept and basic mechanism of semiconductor heterojunctions Describes a series of organic-inorganic semiconductor heterojunctions with desirable electrical and optical properties for optoelectronic devices Discusses typical devices such as solar cells, photo-detectors, and optoelectronic memories Outlines the materials and device challenges as well as possible strategies to promote the commercial translation of semiconductor heterojunctions-based optoelectronic devices Aimed at graduate students and researchers working in solid-state materials and electronics, this book offers a comprehensive yet accessible view of the state of the art and future directions.

Provides first-hand insights into advanced fabrication techniques for solution processable organic electronics materials and devices The field of printable organic electronics has emerged as a technology which plays a major role in materials science research and development. Printable organic electronics soon compete with, and for specific applications can even outpace, conventional semiconductor devices in terms of performance, cost, and versatility. Printing techniques allow for large-scale fabrication of organic electronic components and functional devices for use as wearable electronics, health-care sensors, Internet of Things, monitoring of environment pollution and many others, yet-to-be-conceived applications. The first part of Solution-Processable Components for Organic Electronic Devices covers the synthesis of: soluble conjugated polymers; solution-processable nanoparticles of inorganic semiconductors; high-k nanoparticles by means of controlled radical polymerization; advanced blending techniques yielding novel materials with extraordinary properties. The book also discusses photogeneration of charge carriers in nanostructured bulk heterojunctions and charge carrier transport in multicomponent materials such as composites and nanocomposites as well as photovoltaic devices modelling. The second part of the book is devoted to organic electronic devices, such as field effect transistors, light emitting diodes, photovoltaics, photodiodes and electronic memory devices which can be produced by solution-based methods, including printing and roll-to-roll manufacturing. The book provides in-depth knowledge for experienced researchers and for those entering the field. It comprises 12 chapters focused on: ? novel organic electronics components synthesis and solution-based processing techniques ? advanced analysis of mechanisms governing charge carrier generation and transport in organic semiconductors and devices ? fabrication techniques and characterization methods of organic electronic devices Providing coverage of the state of the art of organic electronics, Solution-Processable Components for Organic Electronic Devices is an excellent book for materials scientists, applied physicists, engineering scientists, and those working in the electronics industry.

It is well known that most important electronic devices use Schottky junctions and heterojunctions. Unfortunately there is not an advanced book introducing heterojunctions systematically. Introduction to Organic Semiconductor Heterojunctions fills the gap. In this book, the authors provide a comprehensive discussion and systematic introduction on the state-of-the-art technologies as well as application of organic semiconductor heterojunctions. First book to systematically introduce organic heterojunctions Arms readers with theoretical, experimental and applied aspects of organic heterojunctions The Chinese edition of the book is part of the Chinese Academy of Sciences’ Distinguished Young Scholar Scientific Book Series Introduction to Organic Semiconductor Heterojunctions is an ideal and valued reference for researchers and graduate students focusing on organic thin film devices like organic light-emitting diodes (OLEDs), organic photovoltaic (OPV) cells, and organic field-effect transistors (OFETs). Instructors can use the book as a supplementary text for a semiconductor physics or organic electronics course, giving students a better feel for the application of organic thin film devices.

This book describes the state-of-the-art advancement in the field of organic electroluminescence contributed by many researchers with internationally established expertise in the field. It includes original contributions on the synthesis of suitable organic materials, fabrication of organic light emitting devices (OLEDs) and organic white light emitting devices (WOLEDs), characterization of these devices and some designs for optimal performance. All chapters are self-sufficient in presenting their contents. The cost effective chemical technology offers many exciting possibilities for OLEDs and organic solar cells (OSCs) to be futuristic solutions for lighting and power generation. A common flexible substrate can be used to fabricate OLEDs on one side facing a room and OSCs on the other side facing the sun. The device thus fabricated can generate power in the day time and light a room/house at night. The book covers developments on OLEDs, WOLEDs and briefly on OSCs as well.

This book presents recent advances in nanostructured materials. It describes the characterization of nanomaterials, their preparation methods and performance testing techniques; the design and development of nano-scale devices; and the applications of nanomaterials, with examples taken from different industries, such as energy, bioengineering and medicine. The book is broadly divided into sections such as nanostructure semiconductor materials for device applications, nanostructured ferroelectric and ferromagnetic materials.. The topics covered include experimental approaches of device fabrication, photovoltaics and supercapacitors applications, etc. Given the contents, the book will be useful for students, researchers, and professionals working in the area of nanotechnology and nanomaterials.

This high-class book reflects a decade of intense research, culminating in excellent successes over the last few years. The contributions from both academia as well as the industry leaders combine the fundamentals and latest research results with application know-how and examples of functioning displays. As a result, all the four important aspects of OLEDs are covered: - syntheses of the organic materials - physical theory of electroluminescence and device efficiency - device conception and construction - characterization of both materials and devices. The whole is naturally rounded off with a look at what the future holds in store. The editor, Klaus Muellen, is director of the highly prestigious MPI for polymer research in Mainz, Germany, while the authors include Nobel Laureate Alan Heeger, one of the most notable founders of the field, Richard Friend, as well as Ching Tang, Eastman Kodak's number-one OLED researcher, known throughout the entire community for his key publications.

In the field of organic semiconductors researchers and manufacturers are faced with a wide range of potential molecules. This work presents concepts for simulation-based predictions of material characteristics starting from chemical stuctures. The focus lies on charge transport – be it in microscopic models of amorphous morphologies, lattice models or large-scale device models. An extensive introductory review, which also includes experimental techniques, makes this work interesting for a broad readership. Contents: Organic Semiconductor Devices Experimental Techniques Charge Dynamics at Dierent Scales Computational Methods Energetics and Dispersive Transport Correlated Energetic Landscapes Microscopic, Stochastic and Device Simulations Parametrization of Lattice Models Drift–Diusion with Microscopic Link

The discovery of highly efficient organic light-emitting diodes (OLEDs) in the 1980s has stimulated extensive research on organic semiconductors and devices. Underlying this breakthrough is the realization of the organic heterojunction (OH). Besides OLEDs, the implementation of the OH also significantly improves the power conversion efficiency in organic photovoltaic cells (OPVs). The continued technological advancements in organic electronic devices depend on the accumulation of knowledge of the intrinsic properties of organic materials and related interfaces. Among them, charge-carrier transport and carrier injection are two key factors that govern the performance of a device.From the point of view of application, an interface chemical doping method is proposed to engineer the carrier injection at an organic heterojunction. It is found that the injection current can be effectively increased or suppressed by introducing a thin (2 nm) doped organic layer at the interface. This technique is further extended to study the impact of an injection barrier at the OH, in OLEDs, on device performance. It is shown that a 0.3 eV injection barrier at the OH, that is normally negligible at metal/organic interface, can reduce the device efficiency by 25%. This is explained by the carrier distribution in the density-of-states at the OH.Furthermore, the carrier transport properties in a bulk heterojunction system are investigated. The bulk heterojunction consists of an interpenetrating network of a polymeric electron donor and a molecular electron acceptor. This material system has been studied in the last few years as an attractive power conversion efficiency (5% under AM 1.5) of OPV cells has been demonstrated. It is found that the electron mobility is greatly dependent on the thermal treatment of the film. Interfacial dipole effect at the heterojunction between the donor and the acceptor is proposed to be the determining factor that alters the carrier mobility in different nanoscale structures.This thesis mainly focuses on the charge carrier injection and transport at organic heterojunctions. The carrier transport properties of different organic materials used in this study are characterized by time-of-flight (TOF) and admittance spectroscopy (AS). An injection model is formulated by considering the carrier distribution at both sides of the interface. Using a steady-state simulation approach, the effect of accumulated charges on energy level alignment at OH is revealed. Instead of a constant injection barrier, it is found that the barrier varies with applied voltage. Moreover, an escape probability function in the injection model is modified by taking into account the total hopping rate and available hopping sites at the interface. The model predicts that the injection current at low temperature can be dramatically modified by an extremely small density of deep trap states. More importantly, the temperature dependence of the injection current is found to decrease with increasing barrier height. This suggests that extracting the barrier height from the J vs 1/T plot, as commonly employed in the literature, is problematic. These theoretical predictions are confirmed by a series of experiments on heterojunction devices with various barrier heights. In addition, the presence of deep trap states is also consistent with carrier mobility measurements at low temperature.