Air Stable Inverted Organic Light Emitting Diodes

This concise volume provides an introduction to the working principles, design, and construction of air-stable inverted organic light-emitting diodes (OLEDs), which lead to the realization of practical flexible electronics. The first part of the book reviews the history of the three generations of inverted OLEDs: hybrid organic inorganic light-emitting diodes (HOILEDs), metal oxides and organic electron injection layer, describing the materials, fabrication techniques, device structure, applications, and technological challenges involved in each case. The second part of the book focuses on the carrier injection mechanism in OLEDs. The book will be of interest to students and researchers working on organic optoelectronics.

This concise volume provides an introduction to the working principles, design, and construction of air-stable inverted organic light-emitting diodes (OLEDs), leading to the realization of practical flexible organic optoelectronics for displays and lighting. The first part of the book considers the requirements for air stability of OLED devices, the challenges involved in achieving air stability and the history of approaches to the problem. It goes on to describe hybrid organic-inorganic LEDs and their carrier injection mechanism, and summarises the early phase of inverted OLED development. The third part focuses on the electron injection layer and interfacial engineering, and finally the book describes the inverted OLED and the carrier injection mechanism in recently-developed devices. The book will be of interest to students and researchers working on practical organic optoelectronics.

Since the invention of the first efficient organic light-emitting diodes (OLEDs) by C. T. Tang and S. VanSlyke, OLEDs have attracted close interest as a promising candidate for next-generation full-color displays and future solid-state lighting sources because of a number of advantages like high brightness and contrast, high luminous efficiency, fast response time, wide viewing angle, low power consumption, and light weight. The recombination of holes and electrons under electrical excitation typically generates 25% singlet excitons and 75% triplet excitons. For traditional fluorescent OLEDs, only 25% singlet excitons can be utilized to emit light, while the other 75% triplet excitons are generally wasted through nonradiative transition. By adopting noble metal phosphorescent complexes, an internal quantum efficiency (IQE) of 100% could be achieved by utilizing both the 25% singlet excitons and 75% triplet excitons. However, these phosphors usually contain nonrenewable and highcost iridium or platinum noble metals. Most recently, unity IQE has been readily achieved through noble metal-free purely organic emitters, such as thermally activated delayed fluorescence (TADF) emitters, hybridized local and charge-transfer state (HLCT) “hot exciton” emitters, binary- or ternary-mixed donor-acceptor exciplex emitters, and neutral p radical emitters, etc. In addition, the combination of conventional p-type hole-transport and n-type electron-transport materials in an appropriate device structure can also provide an uncommon efficiency. Both strategies are essential and attractive for high-performance and low-cost full-color displays and white OLED applications. This Research Topic mainly focus on this new generation of organic light-emitting materials and devices, including design, synthesis, and characterization of light-emitting organic molecules with tunable excited states, and their structural, electrical, and photophysical properties. Contributions relating to carrier transporting materials and corresponding device engineering are also included. Two mini reviews and thirteen original research articles by recognized academic experts in their respective fields are collected in this Research Topic, which will offer a broad perspective of noble metal-free organic light emitters, including conventional fluorescent emitters, TADF emitters, HLCT emitters, exciplex emitters, aggregation-induced emission (AIE) luminogens, and their corresponding devices. We believe this eBook should attract the attention of multidisciplinary researchers in the fields of materials science, organic synthesis, and electronic device engineering, especially for those engaged in OLED-related areas.

This book introduces the recent progress that has resulted from utilizing the idea of "element-block polymers". A structural unit consisting of various groups of elements is called an "element-block." The design and synthesis of new element-blocks, polymerization of these blocks, and development of methods of forming higher-order structures and achieving hierarchical interface control in order to yield the desired functions are expected to result in manifold advantages. These benefits will encourage the creation of new polymeric materials that share, at a high level, electronic, optical, and magnetic properties not achievable with conventional organic polymeric materials as well as forming properties of molding processability and flexible designability that inorganic materials lack. By pioneering innovative synthetic processes that exploit the reactivity of elements and the preparation techniques employed for inorganic element-blocks, the aim is (1) to create a new series of innovative polymers based on the novel concept of element-block polymers, in which the characteristics of elements are extensively combined and utilized, and (2) to formulate theories related to these polymers. This book demonstrates especially the design strategies and the resulting successful examples offering highly functional materials that utilize element-block polymers as a key unit.

Organic Light-Emitting Materials and Devices provides a single source of information covering all aspects of OLEDs, including the systematic investigation of organic light-emitting materials, device physics and engineering, and manufacturing and performance measurement techniques. This Second Edition is a compilation of the advances made in recent years and of the challenges facing the future development of OLED technology. Featuring chapters authored by internationally recognized academic and industrial experts, this authoritative text: Introduces the history, fundamental physics, and potential applications of OLEDs Reviews the synthesis, properties, and device performance of electroluminescent materials used in OLEDs Reflects the current state of molecular design, exemplifying more than 600 light-emitting polymers and highlighting the most efficient materials and devices Explores small molecules-based OLEDs, detailing hole- and electron-injection and electron-transport materials, electron- and hole-blocking materials, sensitizers, and fluorescent and phosphorescent light-emitting materials Describes solution-processable phosphorescent polymer LEDs, energy transfer processes, polarized OLEDs, anode materials, and vapor deposition manufacturing techniques employed in OLED fabrication Discusses flexible display, the backplane circuit technology for organic light-emitting displays, and the latest microstructural characterization and performance measurement techniques Contains abundant diagrams, device configurations, and molecular structures clearly illutrating the presented ideas Organic Light-Emitting Materials and Devices, Second Edition offers a comprehensive overview of the OLED field and can serve as a primary reference for those needing additional information in any particular subarea of organic electroluminescence. This book should attract the attention of materials scientists, synthetic chemists, solid-state physicists, and electronic device engineers, as well as industrial managers and patent lawyers engaged in OLED-related business areas.

Organic solar cells have emerged as new promising photovoltaic devices due to their potential applications in large area, printable and flexible solar panels. Organic Solar Cells: Materials and Device Physics offers an updated review on the topics covering the synthesis, properties and applications of new materials for various critical roles in devices from electrodes, interface and carrier transport materials, to the active layer composed of donors and acceptors. Addressing the important device physics issues of carrier and exciton dynamics and interface stability and novel light trapping structures, the potential for hybrid organic solar cells to provide high efficiency solar cells is examined and discussed in detail. Specific chapters covers key areas including: Latest research and designs for highly effective polymer donors/acceptors and interface materials Synthesis and application of highly transparent and conductive graphene Exciton and charge dynamics for in-depth understanding of the mechanism underlying organic solar cells. New potentials and emerging functionalities of plasmonic effects in OSCs Interface Degradation Mechanisms in organic photovoltaics improving the entire device lifetime Device architecture and operation mechanism of organic/ inorganic hybrid solar cells for next generation of high performance photovoltaics This reference can be practically and theoretically applied by senior undergraduates, postgraduates, engineers, scientists, researchers, and project managers with some fundamental knowledge in organic and inorganic semiconductor materials or devices.

Solution-Processed Organic Light-Emitting Devices provides a comprehensive reference on the principles and advances in materials design, device structures, and processing technologies of organic light-emitting diodes (OLEDs). Most importantly, the book analyses the dynamics of thin-film growth from solutions such as solvent orthogonalization, coffee-ring effects, and interfacial adhesion. Exciton generation and utilization, host–guest energy transfer, and interfacial interaction in the solution-processed films are considered with the material and device design to maximize the electroluminescent performance of OLEDs.The book reviews the materials, devices, and technologies dedicated to solution-processed thin-film devices, which are not only applicable to OLEDs but may be adapted to other emerging semiconducting devices due to the similarity in methods (for instance, quantum-dot LEDs and solar cells, and perovskite-based LEDs/photovoltaics/detectors).This book is suitable for researchers in academia and industry working in the materials science and engineering, chemistry, and physics disciplines. Discusses the most relevant and emerging solution-processable materials for OLED applications Reviews device engineering to address defects, charge transport, and exciton generation in fabricated solution-processable thin films Provides the methods to grow multilayered thin films from solutions with organic semiconductors, with particular attention to new technologies to overcome interfacial mixing effects

This third volume in the Advanced Nanocarbon Materials series covers the topic of flexible electronics both from a materials and an applications perspective. Comprehensive in its scope, the monograph examines organic, inorganic and composite materials with a section devoted to carbon-based materials with a special focus on the generation and properties of 2D materials. It also presents carbon modifications and derivatives, such as carbon nanotubes, graphene oxide and diamonds. In terms of the topical applications covered these include, but are not limited to, flexible displays, organic electronics, transistors, integrated circuits, semiconductors and solar cells. These offer perspectives for today?s energy and healthcare challenges, such as electrochemical energy storage and wearable devices. Finally, a section on fundamental properties and characterization approaches of flexible electronics rounds off the book. Each contribution points out the importance of the structure-function relationship for the target-oriented fabrication of electronic devices, enabling the design of complex components.