Question

The breakdown in a reverse biased $p-n$ junction diode is more likely to occur due to

• A. large velocity of the minority charge carriers if the doping concentration is small
• B. large velocity of the minority charge carriers if the doping concentration is large
• C. strong electric field in a depletion region if the doping concentration is small
• D. none of these

Answer 1

Answer: (B)

large velocity of the minority charge carriers if the doping concentration is large

Answer 2

In reverse biasing, the minority charge carriers will be accelerated due to reverse biasing, which on striking with atoms cause ionisation resulting in secondary electrons and thus produce more number of charge carriers. When doping concentration is large, there will be large number of ions in the depletion region, which will give rise to a strong electric field.