Question

Draw the I − V characteristics of zener diode and explain briefly how reverse current suddenly increase at the breakdown voltage.

Answer 1

I − V characteristics of Zener diode,

Reverse current is due to the flow of electrons from n → p and holes from p → n. As the reverse biased voltage increase the electric field across the junction becomes significant. And when reverse bias voltage V = V_Z, then the electric field strength is high enough to pull electrons from p-side and accelerated to n-side.