The fundamentals and applications of cathodoluminescence are provided in this detailed book. Cathodoluminescence (CL) is a mechanism to identify optical and electronic properties of nanostructures in distinctive materials. Some of the essential topics of evaluation are fundamentals of semiconductors, impurities in oxides and phase determination of minerals. This book deals with carrier concentration, diffusion length, minority carriers in semiconductors, amount of impurity and phase composition in materials. This book encompasses the fundamentals as well as applications of cathodoluminescence to diverse range of materials like thin films, oxides and minerals in the field of material science.