pn juncion diode

Diode Characteristics 

Aim: To study forward bias and reverse bias  characteristics of pn-junction diode.

Instruments required: Diode 1N4007, 1k resistor, ammeter ,voltmeter.

Theory:

forward bias:

When the p-n junction diode is in forward bias, the p-type is connected to the positive terminal of the external voltage, while the n-type is connected to the negative terminal. The potential barrier is reduced when the diode is placed in this fashion. When the voltage is 0.7 V for silicon diodes and 0.3 V for germanium diodes, the potential barriers fall, and current flows.

The current grows slowly while the diode is under forward bias, and the curve formed is non-linear as the voltage supplied to the diode overcomes the potential barrier. Once the diode has crossed the potential barrier, it functions normally, and the curve rises quickly as the external voltage rises, yielding a linear curve.

circuit Diagram:

forward bias: