This book is an introductory text for graduate students, researchers in industries, and those who are just beginning to work on organic electronics materials, devices and their applications. The book includes mainly fundamental principles and theories for understanding organic electronics materials and devices, but also provides information about state-of-the-art technologies, applications and future prospects. These topics encompass physics for organic transistors, structure control technologies of polymer semiconductors, nanomaterials electronics, organic solar cells, organic electroluminescence, liquid semiconductors and dynamics for excitation, among others. This book will help researchers to be able to contribute to society with the technologies and science of organic electronics materials in the future.