PN DIODE

1. R.M.K COLLEGE OF ENGINEERING
AND TECHNOLOGY
DEPARTMENT OF ECE
EC8252-ELECTRONIC DEVICES
SECOND SEMESTER-I YEAR- (2020-2024 BATCH)
Mrs. P.Sivalakshmi AP/ECE
SESSION:8
DATE: 23.04.2021

2. Contents:
Space Charge Width(w)
PN Diode-Zero bias, Forward Bias & Reverse bias of a diode.
Conductivity of a semiconductor
Einstein Relationship for Semiconductor
Diffusion Length

11. P-N Junction at Forward Bias

12. • When an external voltage is applied to the P-N junction making the P
side
• positive with respect to the N side the diode is said to be forward biased.
• The barrier potential difference is decreased by the external applied
voltage. The depletion band narrows which urges majority carriers to
flow across the junction.
• A Forward biased diode has a very low resistance.

13. P-N Junction at Reverse Bias

14. • When an external voltage is applied to the P-N junction making the P side negative
with respect to the N side the diode is said to be Reverse Biased.
• The barrier potential difference increases. The depletion band widens preventing
the movement of majority carriers across the junction.
• A Reverse Bias diode has a very high resistance