Semiconductor Components: N+/N Junction Analysis

This lecture discusses the analysis of N+/N junctions in semiconductor components. It begins with an overview of a silicon bar doped on both sides, one heavily and the other lightly. The instructor explains the diffusion current that occurs when the N+ side contacts the N- side, leading to the formation of an electric field due to the fixed positive charges left behind by diffusing electrons. The equilibrium between the diffusion current and the drift current is established, resulting in a depletion region on the N+ side and an accumulation region on the N- side. The lecture outlines the mathematical framework needed to solve for the electric field, electron concentration, and hole concentration using Maxwell's equations and the principle of mass action. The instructor presents two calculation methods, emphasizing the importance of boundary conditions for solving the equations. The lecture concludes with a graphical representation of the energy levels and charge distributions across the junction, illustrating the built-in potential and the resulting electric field direction.