WHAT IS ZENER DIODE AND ITS USES . WHY ZENER PRODUCES SUDDENLY MAXIMUM SIGNIFICANT CURRENT AFTER BREAKDOWN VOLTAGE . WHAT IS INSIGNIFICANT & SIGNIFICANT CURRENT . GIVE ME DETAIL ALL THESE WITH DIAGRAM AND ALSO EXPLAIN ZENER DIODE AS VOLTAGE REGULATOR AND WHY ZENER HAS CONSTANT VOLTAGE

A zener diode is a special kind of diode which allows current to flow in the forward direction in the same manner as an ideal diode, but will also permit it to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage, "zener knee voltage" or "zener voltage." The device was named after Clarence Zener, who discovered this electrical property.

A conventional solid-state diode will not allow significant current if it is reverse-biased below its reverse breakdown voltage. When the reverse bias breakdown voltage is exceeded, a conventional diode is subject to high current due to avalanche breakdown. Unless this current is limited by circuitry, the diode will be permanently damaged due to overheating. In the case of a large forward bias (current in the direction of the arrow), the diode exhibits a voltage drop due to its junction built-in voltage and internal resistance. The amount of the voltage drop depends on the semiconductor material and the doping concentrations.