This book covers the optical and electrical properties of nanoscale materials with an emphasis on how new and unique material properties result from the special nature of their electronic band structure. Beginning with a review of the optical and solid state physics needed for understanding optical and electrical properties, the book then introduces the electronic band structure of solids and discusses the effect of spin orbit coupling on the valence band, which is critical for understanding the optical properties of most nanoscale materials. Excitonic effects and excitons are also presented...