Understanding the formation and introduction mechanisms of defects in semiconductors is essential to understanding their properties. Although many defect-related problems have been identified and solved over the past 60 years of semiconductor research, the quest for faster, cheaper, lower power, and new kinds of electronics generates an ongoing need for new materials and properties, and so creates new defect-related challenges. This book provides an up-to-date review of the experimental and theoretical methods used for studying defects in semiconductors, focussing on the most recent developments in the methods. These developments largely stem from the requirements of new materials - such as nitrides, the plethora of oxide semiconductors, and 2-D semiconductors - whose physical characteristics and manufacturing challenges are much more complex than in conventional Si/Ge or GaAs. Each chapter addresses both the identification and quantification of the defects and their characteristics, and goes on to suggest routes for controlling the defects and hence the semiconductor properties. The book provides valuable information and solutions for scientists and engineers working with semiconductors and their applications in electronics.