1. To draw the I-V curve of Si diode in forward biased By: Engr.Irshad Raheem Memon

2. OBJECTIVE Objective of this practical is to learn that how a diode can be made forward biased and what are the values of voltage across and current through forward biased diode.

3. Some Concept Regarding Diode & its Forward Bias Operation What is Diode? Diode is a two terminal semiconductor device with an ability to conduct current only in one direction after a certain amount of voltage called barrier potential is applied to it in a proper way.

4. Diode Forward Bias Operation Diode is said to be forward biased; if positive terminal of diode is connected with positive of voltage source and negative terminal of diode is connected with negative of voltage source.

5. Diode Connected in Forward Bias

6. Forward Bias operation Silicon diode will conduct current at 0.7volt and germanium diode will conduct current at 0.3volt when forward biased. 0.7volt is also called barrier potential for silicon diode and 0.3volt is barrier potential for germanium diode. Before the value of voltage across diode reaches its barrier potential; there is very small amount of current that is flowing through diode. After the value of voltage across diode reached its barrier potential; there is a rapid change in the value of current through diode.

7. Detail Operation of Forward Bias with the help of picture Forward Bias Diode showing flow of Majority Carriers and the Voltage due to barrier potential across the Depletion Region Its picture will be shown in next slide

8. Picture Showing F.B Operation

9. V-I Characteristics of Si & Ge Diode

10. Coming Towards Objective Now Required Apparatus:- Few diodes Breadboard Multimeter Connecting wire

11. Procedure Connect positive terminal of a diode with positive of battery and connect negative terminal of a diode with negative of battery and current limiting resistor may also be added in series with diode. Voltmeter is Connected in parallel with diode and Ammeter is connected in series with diode

12. Procedure Figure in Multism

13. OBSERVATION When value of forward voltage across diode is less than its barrier potential; the value of forward current is very small. As soon as value of forward voltage across diode is reached to its barrier potential; there is rapid increase in forward current.

14. ANY QUERY?