Optoelectronics is intertwined with photonics. The book focuses on the study and function of electronic tools that release, identify and control light. As a field of study, it has flourished internationally and enabled many of the currently used conveniences. Because of this universality, novel functions and optical phenomena have led to further modernization. This book covers current achievements by experts around the world. A lot of developed and developing nations have contributed to this attempt. Chapters in this book are written by prominent scientists working in USA, Japan, India, as well as through the joint participation of the US and Moldova scientists. This book also describes properties and applications of optoelectronic devices employing organic and inorganic substances.