Just try to open a electronic equipments and check it PCB, then say what is the importance of diode in electronics. You can see at least two diodes in each PCB. So we want some details about diodes.
Diode is a two terminal electronics components that conducts electric current in only one direction. This unidirectional behavior of diode is called rectification and is used to convert AC signal in to DC signal.
Also diode have a variety of function due to there non linear electrical characteristics.
VI characteristics of diode
According to VI characteristic of diode ,we can divide it in to three parts.
In forward bias diode is start to conduct after the the diode forward voltage drop.
In reverse direction it does not conduct till its reaching its reverse break down voltage.
If we apply a very large reverse bias voltage across the diode, reverse breakdown is occurs and it damages the diode.
Basic working of diode is given in this figure.
Various types of diodes
1) Normal P N diodes
2) Avalanche diodes
3) Cat's whisker / Crystal diodes
4) Constant current diodes
5) Esaki or Tunnel diodes
6) Gunn diodes
7) Light emitting diodes
8) Laser diodes
9) Peltier diodes
10) Photo diodes
11) Point contact diodes
12) PIN diodes
13) Schottkey diodes
14) Super barrier diodes
15) Gold doped diodes
16) Snap off or Step recovery diodes
17) transient voltage suppression diodes
18) Varicap or Varactor diodes
19) Zenor diodes
Various diode symbols
The diodes are now used in a variety of applications due to its various nature. The important field are given below.
1)Radio demodulation
2)Over voltage protection
3)Logic gates
4)Ionizing radio detection
5)Temperature measurements
6)Current steering
7)Rectification
Try to read more article about diodes. I just try to express my practical experience on to this blog. So covering with large detail is not in my interest. So build your own theory.