Q. Avalanche breakdown in a p-n junction diode is due to
A) Sudden shift of Fermi level
B) Increase in the width of forbidden gap
C) Sudden increase of impurity concentration
D) Cumulative effect of increased electron collision and creation of added electron-hole pairs
Explanation
(d) At high reverse voltage, due to high electric field, the minority charge carriers, while crossing the junction acquire very high velocities. These by collision breaks down the covalent bonds generating more carriers. A chain reaction is established giving rise to high current. This mechanism is called avalanche breakdown.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.