P N Junction diode baising

P N Junction diode

Introduction:- Silicon and germanium are the main semiconductors used for production of diode, transistors and Integrated Circuit(ICs.). Semiconductor materials contain 4 electron in their outer most orbit. A pentavalent impurity is added to make P type semiconductor. P type semiconductor has hole in surplus makes them positively charged. A trivalent impurity is added to make N type semiconductor. N type semiconductor has electrons in surplus makes them negatively charged.

PN Junction Diode:- When a P type semiconductor and N type semiconductor are bring together by doping they form a PN Junction diode. In this Junction there are more holes in P layer and more electrons in N layer.

Baising:-

Forward bais:-When Positive voltage is given to P layer and Negative voltage is given to N layer the junction is said to be forward baised. Due to emf of cell holes from P layer and electrons from N layer moves towards the junction and current starts flowing.This is forward bais condition where diode starts conducting.

Reversed bais:-When Negative voltage is given to P layer and Positive voltage is given to N layer the junction is said to be reversed baised. Due to emf of cell holes from P layer and electrons from N layer moves away from junction so that no current can flow through junction.This is reversed bais condition where diode can not conduct.