Semiconductors: Equilibrium Properties and Charge Dynamics

This lecture discusses the properties of semiconductors at equilibrium, focusing on intrinsic semiconductors and the effects of temperature on charge carriers. It begins by reviewing the behavior of semiconductors at absolute zero, where the valence band is full and the conduction band is empty. The instructor explains how temperature influences the occupation of energy states, leading to the generation of electron-hole pairs. The movement of free electrons and holes is described, highlighting their independent behavior and the concept of charge neutrality. The lecture also covers the generation and recombination of electron-hole pairs, illustrating how these processes maintain charge balance in the material. The properties of electrons and holes, including their effective mass and response to external forces, are analyzed. The instructor emphasizes the importance of understanding these dynamics for applications in semiconductor devices, providing a comprehensive overview of the fundamental principles governing semiconductor behavior at equilibrium.