Aim	To draw the I-V characteristics curves of a p-n junction in forward bias and reverse bias.
Apparatus Required	P-N junction diode DC power supply Rheostat or potentiometer Ammeter Voltmeter Connecting wires
Theory	A p-n junction is formed by joining a p-type semiconductor (with excess holes) and an n-type semiconductor (with excess electrons) together. When a forward bias voltage is applied across the p-n junction, the holes from the p-type semiconductor diffuse across the junction and combine with the electrons in the n-type semiconductor, creating a flow of current. When a reverse bias voltage is applied across the p-n junction, the electrons and holes are pushed away from the junction, creating a depletion region with no charge carriers.
Procedure	Connect the p-n junction diode to the DC power supply, rheostat or potentiometer, ammeter, and voltmeter using connecting wires. Set the rheostat or potentiometer to its minimum value. Connect the ammeter in series with the p-n junction diode and the voltmeter in parallel. Gradually increase the forward bias voltage by adjusting the rheostat or potentiometer and record the corresponding values of current and voltage. Plot the I-V characteristics curve for the p-n junction in forward bias. Reverse the connections of the p-n junction diode with the DC power supply. Repeat steps 2-5 for the reverse bias voltage and record the corresponding values of current and voltage. Plot the I-V characteristics curve for the p-n junction in reverse bias.
Observation and Result	Observation: In forward bias, the current increases rapidly with increasing voltage. In reverse bias, the current initially remains low but increases rapidly at a certain voltage known as the breakdown voltage. The I-V characteristics curve for forward bias is non-linear, while the curve for reverse bias is linear. Result: The I-V characteristics curves for the p-n junction diode in forward and reverse bias have been successfully plotted. The curves show the relationship between current and voltage for the p-n junction diode in different bias conditions. The breakdown voltage for the p-n junction diode in reverse bias can be determined from the curve.