PNkoppeling

PNkoppeling, often written PN-koppeling, refers to the interface between p-type and n-type semiconductor regions forming a PN junction. This junction is a fundamental building block in many semiconductor devices. It arises when p-type material, rich in holes, is placed next to n-type material, rich in electrons. Diffusion of charge carriers creates a depletion region where mobile carriers are depleted, leaving charged dopant ions and an internal electric field. The resulting built-in potential opposes further diffusion.

In operation, applying forward bias (positive voltage on the p-side) lowers the barrier, allowing substantial current to flow. Under reverse bias, the barrier increases and the current is greatly reduced, limited mainly by leakage and, at high voltages, breakdown phenomena. Typical forward voltage drops for silicon PN junctions are around 0.6–0.7 V; reverse breakdown voltages vary with device design and material quality. Junction properties depend on dopant concentrations and how abruptly the junction transitions from p-type to n-type, affecting current, capacitance, and speed.

Manufacturing methods include diffusion of dopants, ion implantation, and epitaxial growth, followed by annealing to activate dopants and form a clean, abrupt interface. PN junctions are found in many devices, notably diodes (rectifiers), light-emitting diodes (LEDs), solar cells, photodiodes, and as the base-emitter or other junctions in transistors.

In sum, the PN koppeling is a pivotal concept in electronics, enabling rectification, light emission, energy conversion, and amplification through controlled charge transport at the p–n interface.