Diodes are two terminal electric components with infinite conductivity in one direction and infinite resistance in other direction .is a type of electrical breakdown in a reverse biased p-n diode in which the electric field enables tunneling of electrons from the valence to the conduction band of a semiconductor .
| Zener Breakdown | Avalanche Breakdown |
|---|---|
| In the Zener effect or Zener breakdown , the electric field enables tunneling of electrons from the valence to the conduction band of a semiconductor in a reverse biased p-n diode . Both sides of PN junction are heavily doped in zener breakdown | The avalanche breakdown occurs when carriers in the transition region are accelerated by the electric field to energies sufficient to create mobile or free electron-hole pairs via collisions with bound electrons. Both sides of PN junction are lightly doped in avalanche breakdown . |
| Zener current is independent of applied voltage . | Charge carriers acquire energy from the applied potential . |
| A strong electric field is produced . | Electric field produced is weak in nature . |
| Large number of holes and electrons are produced . | Electron hole pairs are generated . |