Question

The breakdown voltage for Si is knows as 0.7 volt.If all diodes is made from semiconductors materials junction.How does zener diodes breakdown voltage (PIV) can be 800V - 1N44006

Answer 1

The forward voltage (anode positive with respect to cathode) for a silicon diode is around 0.7 volt. The reverse breakdown voltage (anode negative with respect to cathode) can be much higher.
A zener diode is a special diode with increased amounts of doping. This is to compensate for the damage that occurs in the case of a pn junction diode when the reverse bias exceeds the breakdown voltage and thereby current increases at a rapid rate.

Answer 2

Thanks for help.

Answer 3

You're welcome :)