PNdiodit

PNdiodit, or PN diode, is a semiconductor device formed by joining p-type and n-type semiconductor regions to create a PN junction. The p-type region contains an abundance of holes as charge carriers, while the n-type region contains electrons. When manufactured, diffusing dopants creates a depletion region at the interface and an internal electric field that influences current flow.

In operation, the diode conducts readily in forward bias, when the p-side is connected to a higher potential than the n-side, allowing carriers to cross the junction and produce a sizable current. In reverse bias, the depletion region widens and only a small leakage current flows until a breakdown voltage is reached. The current–voltage behavior is highly nonlinear and is often described by the diode equation I = Is (exp(V/(nVT)) − 1), where Is is the saturation current, V is the applied voltage, and VT is the thermal voltage.

Silicon is the most common base material; p-type regions are typically doped with acceptors (e.g., boron) and n-type regions with donors (e.g., phosphorus). A typical silicon PN diode has a forward voltage drop of about 0.6–0.7 V at moderate current and a reverse leakage current that increases with temperature. Breakdown voltage depends on design and doping levels.

Applications include rectification in power supplies, signal demodulation, clipping and protection circuits, and various switching roles. Variants based on the same PN junction principle include small-signal diodes and rectifier diodes; other devices such as Zener diodes use controlled breakdown for regulation.