Luminescence is presently, and will continue to be, a challenging field of research in materials science, solid-state physics and chemistry. Recent progress in optoelectronic and display technology continues to drive this field in the search for new luminescent materials. Demands on new procedures for synthesis, and understanding underlying luminescence processes in these materials, will create new opportunities for both fundamental and applied research. This book is a compilation of papers, both invited and solicted, from around the world that focus on luminescence and luminescent materials - from theory and modeling, characterization of luminescent materials, and systems with confined structures such as nanocrystallites and quantum wells and dots, to synthesis and device applications.