The photodiode is used to detect the optical signals. These diodes are preferably operated in reverse biased mode because:
- (A)fractional change in majority carriers produce higher forward bias current
- (B)fractional change in majority carriers produce higher reverse bias current
- (C)fractional change in minority carriers produce higher forward bias current
- (D)fractional change in minority carriers produce higher reverse bias current✓ Correct
Answer: (D)
Solution
Photodiodes are operated in reverse bias mode because in this mode, the reverse current is primarily due to minority carriers. When light falls on the photodiode, it generates electron-hole pairs, increasing the minority carrier concentration. Even a small fractional change in minority carriers produces a significant change in the reverse bias current, making the device highly sensitive to optical signals.
JEE Main · 2022 · 25 Jun 2022 · Shift 1 · Single correct option