P-N JUNCTION DIODE

P-N JUNCTION DIODE :-

It is one of the most usable electronics element . It is made up of semiconductors of p- type and n- type, when we join both semiconductors it forms a junction between them, hence the junction is from this name.

This device has two terminals / electrodes one from n-type semiconductor and second from p-type semiconductor . Due to the two electrodes it is called DIODE, i.e. di + electrode.

To connect the external terminals , a metal is applied to the heavily doped n-type and p-type semiconductor. which is called ohmic contact.
The drop across the contact is very small which do not affect the performance of the device.

DIAGRAMS AND SYMBOLS :-

p-n junction diade

symbol

BIASING :- 

To operate the diode we need to know about the biasing .

our diode works short circuit when it is in the forward biased, means it pass current on it.
and when it is reverse biased it act as a open circuit, means it do not allow to pass current on it.
FORWARD BIASING:-
the p terminal of diode is connected to the positive terminal of the battery and the n terminal of diode is connected to the negative terminal of the battery.
shown the fig.


REVERSE BIASING:-
the n terminal of diode is connected to the positive terminal of the battery and the p terminal of diode is connected to the negative terminal of the battery.
shown the fig.

USE OF DIODE :-

It allow to flow current only in one direction so it is use in rectifier circuits.
And also to send information or signal in only one direction.