The book begins with the principles of LED lighting, then focuses on issues and challenges. Chapters are devoted to key steps in LED manufacturing: substrate, epitaxy, process and packaging. Photoelectric characterization of LEDs, Lighting with LEDs and the imposition of a certain level of color quality, are the subject of later chapters, and finally there is a detailed discussion of the emergence of OLEDs, or organic LEDs, which have specific capabilities of immediate interest and importance in this field.