Q200 / 200 · MHT CET - Medical 2026 (22 April Shift 2) · Physics
The depletion region of a p-n junction is formed due to
- Adrift of majority carriers under the influence of an applied electric field.
- Bthermal energy exciting electrons from the p-side to the n-side.
- Correct answerCdiffusion of majority carriers across the junction immediately after formation, leaving behind fixed immobile ions.
- Dthe physical removal of material at the junction interface during manufacturing
Solution
When a p-n junction is formed, there is a concentration gradient of charge carriers across the junction.
Due to this gradient, majority carriers diffuse across the junction. Holes diffuse from the p-side to the n-side, and electrons diffuse from the n-side to the p-side.
As these mobile charge carriers cross the junction, they leave behind uncompensated, fixed immobile ions (negative acceptor ions on the p-side and positive donor ions on the n-side).
This region near the junction, which is depleted of mobile charge carriers and contains only fixed immobile ions, is called the depletion region.
Answer: diffusion of majority carriers across the junction immediately after formation, leaving behind fixed immobile ions.
Due to this gradient, majority carriers diffuse across the junction. Holes diffuse from the p-side to the n-side, and electrons diffuse from the n-side to the p-side.
As these mobile charge carriers cross the junction, they leave behind uncompensated, fixed immobile ions (negative acceptor ions on the p-side and positive donor ions on the n-side).
This region near the junction, which is depleted of mobile charge carriers and contains only fixed immobile ions, is called the depletion region.
Answer: diffusion of majority carriers across the junction immediately after formation, leaving behind fixed immobile ions.
Hence, the correct answer is option: 'C'.