Lecture
This lecture covers the principles of metal-semiconductor junctions, focusing on their historical development and thermodynamic equilibrium. It begins with the historical context, highlighting key discoveries in the field, such as the first metal-galena junction by Ferdinand Braun in 1873 and its applications in radio technology. The instructor explains the construction of a metal-semiconductor junction, detailing the roles of metals and semiconductors, and the significance of energy levels, including the Fermi level and work function. The lecture further explores thermionic emission, discussing how electrons can escape from the semiconductor and the conditions that lead to thermal ionization. The concept of thermodynamic equilibrium is introduced, illustrating how emission and absorption of electrons balance out in a system. The instructor also examines the potential barrier height and depletion region in metal-semiconductor junctions, emphasizing the importance of these factors in device performance. The lecture concludes with practical examples of different metals and semiconductors, summarizing the equilibrium conditions and their implications for semiconductor technology.