Aim:

To plot the V-I characteristics of the solar cell

Apparatus Required:

1. Solar cell
2. Bread board
3. Light source
4. Ammeter (0-5mA)
5. Voltmeter (0-5V)
6. Connecting Wires

Theory:

A solar cell is a semiconductor device which converts solar energy into electrical energy. It is also called Photovoltaic cell. Solar cell works as a PN junction diode. A built in depletion region is generated in that without an applied reverse bias voltage. Photos of adequate energy create electron-hole pairs and a potential is generated across the solar cell.

The e.m.f. generated by the solar cell in the open circuit (when no current is drawn from it) is denoted by V_OC. This is the maximum value of the e.m.f. When a high resistance is introduced in the external circuit a small current flows through it and the voltage decreases. The voltage goes on falling and the current goes on increasing as the resistance is reduced to zero the current rises to its maximum value known as saturation current and it is denoted as I_SC here the voltage becomes zero.

The product of open circuit voltage V_OC an short circuit current I_SC is known as ideal power.

Circuit Diagram:

Ideal Graph:

Procedure:

• Place the solar cell and the light source opposite to each other on a wooden plank.
• Select the voltmeter range, ammeter range and a resistance box.
• Switch on the lamp to escape the light on solar cell.
• Set the distance between solar cell and the lamp.
• Vary the load resistance and intensity and note the current –voltage readings.
• Plot the graph between output voltages versus output current.

Observations:

Load Resistance (RL)	Φ =		Φ =		Φ =		Φ =
	VP(V)	IP(mA)	VP(V)	IP(mA)	VP(V)	IP(mA)	VP(V)	IP(mA)

Open Circuit

Φ	Φ =	Φ =	Φ =	Φ =
VP

Short Circuit

Φ	Φ =	Φ =	Φ =	Φ =
IP

Result:

The more far the light from the solar cell, less electricity is produced.

Precautions:

1. The solar cell should be exposed to sun light before using it in the experiment.
2. Light from the lamp should fall normally on the solar cell.