Introduction to Solids and Semiconductors

This chapter is an introduction to solids and semiconductors. Unit cells and the lattice parameter defining the different types of solids have been introduced. The concept of Miller indices follows this as a tool to numerically identify and tag different lattice planes in solids. We discuss classical free electron theory before taking the concepts given by Sommerfeld's free electron theory. Density of states and quantum free electron theory are discussed in detail using the concept of Fermi-Dirac probability function. This introduces the fermi level and the occupancy probability. With the aid of Bloch's theorem and introducing certain modifications, the Kronig-Penney model and the origin of the energy band have been discussed. Finally, based on the Kronig-Penney energy band concept, different types of solids like insulators, conductors, and semiconductors have been introduced in terms of energy band gap in electron volts.