Question

How many types of diodes are there?

Answer 1

In order to solve this question we need to understand p-type and n-type semiconductors. Semiconductor are those materials whose conductivity lies within the conductor and insulator. P-type semiconductor are those semiconductors which is doped with atoms having atomic number in multiple of $3$ so when they are doped with silicon or germanium, bonding occurs between $3$ electrons but one bond place is vacant so an electron from neighboring atom jump to vacant position and thereby creating a vacancy at its own position, this is called hole, so a hole is of positive charge.

Complete answer:
N-type semiconductors are those semiconductors which are doped with atoms having atomic numbers in multiples of $5$ so when they are doped with Silicon or Germanium then $4$ bonds are made but there is one free electron having a negative charge. So before understanding how many types of diodes, let us know what diodes are. Diodes are combinations of p-type and n-type semiconductors or it’s a two terminal electrical check valve that allows the flow of current in one direction.

Diodes can operate in forward biasing and reverse biasing. Forward biasing means the p side is connected to the positive side and the n terminal to the negative side of the battery.Normal diodes conduct in this manner. Reverse biasing means p type connected to the negative side of the battery and n side connected as positive side. In normal there is avalanche breakdown so it could not conduct current whereas zener diodes operate in reverse biasing. There are mainly $11$ types of diodes used in various applications.
(i) photo diode
(ii) Gunn diodes
(iii) PIN diodes
(iv) Tunnel Diode
(v) LED diode
(vi) Varactor diode
(vii) Schottky diode
(viii) PN diode
(ix) Vacuum Diode
(x) Laser diode
(xi) Zener diode

Note: It should be remembered that types of diodes depend on application or mode of operation. While the diodes are in reverse bias there can be two breakdown namely avalanche breakdown and zener breakdown. In avalanche breakdown minority charge carrier current flows which damage the junction from overheating.