- Zener Breakdown Definition: Zener Breakdown is the process where a high electric field in a heavily doped diode causes a sudden increase in current by breaking covalent bonds and releasing valence electrons.
- High Electric Field: A narrow depletion region in a reverse-biased diode creates a high electric field, essential for Zener Breakdown.
- Controllability: The number of charge carriers in Zener Breakdown can be controlled by adjusting the electric field.
- Safe Voltage Levels: Zener Breakdown usually happens below 5V, and with proper heat management, it doesn’t damage the diode.
- Temperature Impact: The Zener Breakdown Voltage decreases with an increase in junction temperature, indicating a negative temperature coefficient.
In a heavily doped semiconductor diode, the depletion region is very narrow. When this diode is in reverse bias, the narrow depletion region creates a high electric field across the junction. For instance, a 3V reverse voltage across a 100 Ao thick depletion region results in a strong electric field.
The strong electric field breaks several covalent bonds in the p-n junction, releasing valence electrons. These excited electrons move to the conduction band, causing a sudden increase in current flow. This process is called Zener Breakdown, and the voltage at which it occurs is the Zener Breakdown Voltage (VZ). Dr. Clarence Zener first observed and explained this phenomenon in 1934, which is why it’s named after him.
Zener Breakdown is a controllable phenomenon, as the number of charge carriers can be managed by adjusting the electric field. Typically, Zener Breakdown occurs below 5V and won’t damage the diode if heat is properly managed. The Zener Breakdown Voltage decreases as the junction temperature increases, showing a negative temperature coefficient. This voltage can be adjusted during manufacturing. Zener diode are widely used based on the Zener effect and Zener Breakdown Voltage.
