Understanding Semiconductor Equilibrium: Concepts and Applications

This lecture covers the principles of semiconductor physics, focusing on homogeneous and inhomogeneous semiconductors at thermal equilibrium. It begins with the definition of vacuum energy and its implications for semiconductor behavior. The instructor explains how to draw energy bands based on affinity, band gap, and intrinsic material properties. The energy of Fermi is discussed, emphasizing its constancy throughout the structure. The lecture also addresses the conditions for semiconductors under equilibrium and non-equilibrium states, detailing the effects of current flow. The instructor illustrates the differences between homogeneous and inhomogeneous semiconductors, providing insights into their respective energy band structures. The importance of external voltage in determining energy levels is highlighted, along with the graphical representation of energy bands. The lecture concludes with a discussion on the implications of these concepts for semiconductor applications in technology.