To draw the I – V characteristics curve of p-n junction in forward bias & reverse bias

Aim

To draw the I – V characteristics curve of p-n junction in forward bias & reverse bias.

Apparatus

A p-n junction semi-conductor diode, a three volt battery, a high resistance, a rheostat, a voltmeter (0- 3v), a milli ammeter (0-.30 mA), one – way key, connecting wires.

Observations:

Least count of voltmeter = 0.02 & 1 v/div Zero error = –

Least count of milli-ammeter = 0.2 mA/div Zero error = –

Least count of micro-ammeter = 2μ A/div Zero error = –

Observations Table :

Calculations:

Graph is plotted between forward – bias voltage (V _F) (on x-axis) and forward current, I _F (on y – axis)

Scale: X – axis: 1 cm = V of V _F Y – axis: 1 cm = mA of I _F

Graph is plotted between reverse bias voltage, V_R(along X’ axis) and reverse current, I _R(along Y’ axis).

Scale: X’ axis = 1 cm = V of V_R Y’ axis = 1 cm = μA of I_F

Result:

The obtained curves are the characteristics curves of the semi-conductor diode.

Precautions:

1. All connections should be neat, clean & tight.
2. Key should be used in circuit & opened when the circuit is not being used.
3. Forward bias voltage beyond breakdown should not be applied.

Sources of error:

The junction diode supplied maybe faulty.