Zenerdurchbruch

Zenerdurchbruch is a phenomenon observed in semiconductor diodes, specifically at a certain reverse voltage. When a Zener diode is operated in reverse bias, and the voltage across it reaches a specific value known as the Zener voltage, a significant increase in current flows through the diode. This occurs because the intense electric field within the depletion region of the semiconductor junction becomes strong enough to pull electrons out of their covalent bonds, leading to a surge in charge carriers.

This process is distinct from avalanche breakdown, which occurs at higher reverse voltages. In avalanche breakdown, the few free electrons present in the depletion region are accelerated by the electric field to high enough energies that they collide with atoms, creating more electron-hole pairs. These new carriers are also accelerated and cause further collisions, leading to an avalanche effect. Zener breakdown, however, is primarily a quantum mechanical tunneling effect.

Zener diodes are specifically designed and manufactured to operate reliably in the Zener breakdown region. Their primary application is voltage regulation. By connecting a Zener diode in reverse bias parallel to a varying voltage source, it will maintain a nearly constant voltage across itself once the Zener voltage is reached, effectively acting as a voltage reference or stabilizer. This makes them crucial components in power supply circuits and other electronic systems where a stable voltage is required.