Q142 / 150 · MHT CET 2026 (15 April Shift 1) · Physics
Photodiode is a device
- Ain which photocurrent is dependent on reverse bias.
- Bin which photocurrent is independent of incident radiation.
- Cwhich is always operated in forward bias.
- Correct answerDwhich is always operated in reverse bias.
Solution
A photodiode is a p-n junction fabricated from a photosensitive semiconductor and provided with a transparent window to allow light to fall on its junction.
It is always operated under reverse bias. When the photodiode is illuminated with light (photons) with energy $h\nu$ greater than the energy gap $E_g$ of the semiconductor, electron-hole pairs are generated due to the absorption of photons.
Operating it in reverse bias makes it easier to observe changes in current with light intensity, because the fractional change in minority carrier current is much larger than the fractional change in majority carrier current (which would dominate in forward bias).
The photocurrent is directly proportional to the intensity of incident radiation and is largely independent of the reverse bias voltage.
Answer: which is always operated in reverse bias.
It is always operated under reverse bias. When the photodiode is illuminated with light (photons) with energy $h\nu$ greater than the energy gap $E_g$ of the semiconductor, electron-hole pairs are generated due to the absorption of photons.
Operating it in reverse bias makes it easier to observe changes in current with light intensity, because the fractional change in minority carrier current is much larger than the fractional change in majority carrier current (which would dominate in forward bias).
The photocurrent is directly proportional to the intensity of incident radiation and is largely independent of the reverse bias voltage.
Answer: which is always operated in reverse bias.
Hence, the correct answer is option: 'D'.