Basics of diode-Must Know

Doping-A Process that increase the concentration of free charge carriers such as electrons and holes.

Here an illustration for easy understanding

(Image: Funny illustration of Doping)

Doping level-Only one impurity atom is added to about 10^8 atoms.so that it doesnt affect the crystal sructure.

• The pure semiconductor behaves as a perfect insulator at absolute 0 temperature. 
• The current flow through is of the order of Milli Ampere. So,milli ammeter is used to measure.
• The typical value of the static resistance of a diode may be 50 ohm  .

Types of diode

Power Diode-Extensively used as rectifiers(convertes AC to DC).

(Image: Power Diode)

Main Application -High voltage DC power supplies

Zener Diode-It is a special purpose diode that is operated in reverse bias conditon.

When used in forward bias,it behaves like a simple PN junction.

(Image: Zener Diode)

Main Application -Voltage Regulators

Varacter Diode-Also a special purpose diode with a junction capacitance that can be varied by a    applied voltage. 

Always used in reverse condition.

(Image:Varacter Diode)

                                                                       
  

Main Application-FM Modulator and Tuning circuits 

Point contact diodes-It has it name because theP-N junction is made using semi-conducting material and a thin metallic point.

(Image:PC Diode)

Main Application -Am Receivers