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This book highlights state-of-the-art in III-nitrides-based light-emitting diodes (LEDs). Motivated by the application prospects in lighting, high-resolution display, and health & medicine, the book systematically introduces the physical fundamentals, epitaxial growth, and device fabrications of III-nitride-based LEDs. Important topics including the structures of chips, device reliability and measurements and the advances in mini and micro LEDs are also discussed. The book is completed with a decade of research experience of the author's team in the design and fabrication of III-nitrides-based LEDs, presenting the novel achievements in the stress control of the large mismatch heterostructures, defect formation and inhibition mechanism of the heteroepitaxial growth, LED epitaxial technologies, and the fabrication of high-efficient flip-chip LEDs. The book comprises of a valuable reference source for researchers and professionals engaged in the research and development of III-nitrides-based LEDs.

This book focuses on basic fundamental and applied aspects of micro-LED, ranging from chip fabrication to transfer technology, panel integration, and various applications in fields ranging from optics to electronics to and biomedicine. The focus includes the most recent developments, including the uses in large large-area display, VR/AR display, and biomedical applications. The book is intended as a reference for advanced students and researchers with backgrounds in optoelectronics and display technology. Micro-LEDs are thin, light-emitting diodes, which have attracted considerable research interest in the last few years. They exhibit a set of exceptional properties and unique optical, electrical, and mechanical behaviors of fundamental interest, with the capability to support a range of important exciting applications that cannot be easily addressed with other technologies. The content is divided into two parts to make the book approachable to readers of various backgrounds and interests. The first provides a detailed description with fundamental materials and production approaches and assembly/manufacturing strategies designed to target readers who seek an understanding ofof essential materials and production approaches and assembly/manufacturing strategies designed to target readers who want to understand the foundational aspects. The second provides detailed, comprehensive coverage of the wide range of device applications that have been achieved. This second part targets readers who seek a detailed account of the various applications that are enabled by micro-LEDs.

Comprehensive in scope, this book covers the latest progresses of theories, technologies and applications of LEDs based on III-V semiconductor materials, such as basic material physics, key device issues (homoepitaxy and heteroepitaxy of the materials on different substrates, quantum efficiency and novel structures, and more), packaging, and system integration. The authors describe the latest developments of LEDs with spectra coverage from ultra-violet (UV) to the entire visible light wavelength. The major aspects of LEDs, such as material growth, chip structure, packaging, and reliability are covered, as well as emerging and novel applications beyond the general and conventional lightings. This book, written by leading authorities in the field, is indispensable reading for researchers and students working with semiconductors, optoelectronics, and optics. Addresses novel LED applications such as LEDs for healthcare and wellbeing, horticulture, and animal breeding; Editor and chapter authors are global leading experts from the scientific and industry communities, and their latest research findings and achievements are included; Foreword by Hiroshi Amano, one of the 2014 winners of the Nobel Prize in Physics for his work on light-emitting diodes.

This thesis considers molecular orientation in thin films and introduces an optical model describing this orientation as applied to organic light-emitting diodes (OLEDs). It also describes the electronic structure of intermolecular charge transfer excitons correlated to molecular orientation in solids.It has long been known that molecular orientation influences the electrical and optical properties of molecular films. One notable example is in liquid crystals where rigid rod or disk shaped molecules are commonly used. Understanding the origin of the molecular orientation and its control by surface treatment and electric field resulted in the development of liquid crystal displays. The same thing has happened in organic electronics, and considerable effort has been devoted to understanding and controlling molecular orientation in solid films to improve charge carrier mobility and light absorption, ultimately to improve the performance of organic solar cells and thin film transistors.In contrast, less attention has been paid to molecular orientation and its influence on the characteristics of OLEDs, probably because of the use of amorphous films rather than micro-crystalline films, and it is only in recent years that some molecular films are known to have preferred orientation. This thesis addresses this topic, focusing on OLEDs, describing the origin and control of the orientation of phosphorescent Ir complexes possessing spherical shape rather than rod or disk shape, the simulation of the optical characteristics of OLEDs influenced by preferred molecular orientation, and finally the orientation of intermolecular charge transfer excitons and its correlation to electronic structures in thin films.

The significance of the development of solid-state lighting was underscored by the award of a Nobel Prize in 2014. It is important to build upon this work and to produce practical and versatile sources of quantum light, because these are essential components for the advancement of quantum photonic devices. These devices, in turn, promise new technologies that have the potential to revolutionize society. This book explores various ways of coupling quantum light into, and out of, solid-state emitters. The research presented here has led to important discoveries that will help overcome major challenges in this field.

The revised edition of this important book presents updated and expanded coverage of light emitting diodes (LEDs) based on heteroepitaxial GaN on Si substrates, and includes new chapters on tunnel junction LEDs, green/yellow LEDs, and ultraviolet LEDs. Over the last two decades, significant progress has been made in the growth, doping and processing technologies of III-nitride based semiconductors, leading to considerable expectations for nitride semiconductors across a wide range of applications. LEDs are already used in traffic signals, signage lighting, and automotive applications, with the ultimate goal of the global replacement of traditional incandescent and fluorescent lamps, thus reducing energy consumption and cutting down on carbon-dioxide emission. However, some critical issues must be addressed to allow the further improvements required for the large-scale realization of solid-state lighting, and this book aims to provide the readers with details of somecontemporary issues on which the performance of LEDs is seriously dependent. Most importantly, it describes why there must be a breakthrough in the growth of high-quality nitride semiconductor epitaxial layers with a low density of dislocations, in particular, in the growth of Al-rich and In-rich GaN-based semiconductors. The quality of materials is directly dependent on the substrates used, such as sapphire and Si, and the book discusses these as well as topics such as efficiency droop, growth in different orientations, polarization, and chip processing and packaging technologies. Offering an overview of the state of the art in III-Nitride LED science and technology, the book will be a core reference for researchers and engineers involved with the developments of solid state lighting, and required reading for students entering the field.

This book presents the recent achievements towards the next generation of Light-emitting electrochemical cells (LEC). Its first part focus on the definition, history and mechanism of LEC, going then to concepts and challenges and, finally, giving the reader examples of current application of new electroluminescent materials. The chapters are written by different international groups working on LEC.

This handbook addresses the development of energy-efficient, environmentally friendly solid-state light sources, in particular semiconductor light emitting diodes (LEDs) and other solid-state lighting devices. It reflects the vast growth of this field and impacts in diverse industries, from lighting to communications, biotechnology, imaging, and medicine. The chapters include coverage of nanoscale processing, fabrication of LEDs, light diodes, photodetectors and nanodevices, characterization techniques, application, and recent advances. Readers will obtain an understanding of the key properties of solid-state lighting and LED devices, an overview of current technologies, and appreciation for the challenges remaining. The handbook will be useful to material growers and evaluators, device design and processing engineers, newcomers, students, and professionals in the field.

Light emitting diodes (LEDs) are already used in traffic signals, signage lighting, and automotive applications. However, its ultimate goal is to replace traditional illumination through LED lamps since LED lighting significantly reduces energy consumption and cuts down on carbon-dioxide emission. Despite dramatic advances in LED technologies (e.g., growth, doping and processing technologies), however, there remain critical issues for further improvements yet to be achieved for the realization of solid-state lighting. This book aims to provide the readers with some contemporary LED issues, which have not been comprehensively discussed in the published books and, on which the performance of LEDs is seriously dependent. For example, most importantly, there must be a breakthrough in the growth of high-quality nitride semiconductor epitaxial layers with a low density of dislocations, in particular, in the growth of Al-rich and and In-rich GaN-based semiconductors. The materials quality is directly dependent on the substrates used, such as sapphire, Si, etc. In addition, efficiency droop, growth on different orientations and polarization are also important. Chip processing and packaging technologies are key issues. This book presents a comprehensive review of contemporary LED issues. Given the interest and importance of future research in nitride semiconducting materials and solid state lighting applications, the contents are very timely. The book is composed of chapters written by leading researchers in III-nitride semiconducting materials and device technology. This book will be of interest to scientists and engineers working on LEDs for lighting applications. Postgraduate researchers working on LEDs will also benefit from the issues this book provides.

The control of optical modes in microcavities or in photonic bandgap (PBG) materials is coming of age! Although these ideas could have been developed some time ago, it is only recently that they have emerged, due to advances in both atomic physics and in fabrication techniques, be it on the high-quality dielectric mirrors required for high-finesse Fabry­ Perot resonators or in semiconductor multilayer deposition methods. Initially the principles of quantum electro-dynamics (QED) were demonstrated in elegant atomic physics experiments. Now solid-state implementations are being investigated, with several subtle differences from the atomic case such as those due to their continuum of electronic states or the near Boson nature of their elementary excitations, the exciton. Research into quantum optics brings us ever newer concepts with potential to improve system performance such as photon squeezing, quantum cryptography, reversible taps, photonic de Broglie waves and quantum computers. The possibility of implementing these ideas with solid-state systems gives us hope that some could indeed find their way to the market, demonstrating the continuing importance of basic research for applications, be it in a somewhat more focused way than in earlier times for funding.

Special topic volume with invited papers only

Wide bandgap light emitters include laser diodes and light-emitting diodes (LED), the most modern diodes widely used in current technologies as microelectronics and optoelectronics. Rapid advances have been made during the last few years, with the result that more research is devoted to applications in line with the expanding market for optoelectronics. This volume deals with recent research results on wide bandgap light emitting materials, introducing new concepts for devices based on these materials. The editors, scientists with the best reputations, have invited authors from different institutions who are acknowledged researchers in the field as well as being involved in industrial applications. They represent several lines of research: III-nitride compounds, ZnO and ZnSe, the most promising materials for device applications.