Question

Which bias condition is used preferably in a photodiode?

Answer 1

Photodiode:

• Photodiode is a semiconductor device and it also called as photo detector as it can change the optical signals into electrical signals.

Use of a photodiode:

• Photodiode is a $\mathrm{PN}$ junction diode which is an microelectronic tool in which current carriers are generated by photons via photo excitation means photoconduction by light.
• Compared to minority carriers, the fractional increase in the majority of carriers is significantly lower.
• So, the fractional change due to the photo-effects on the minority carriers dominated reverse bias current is more easily measurable than the fractional change in the majority carrier dominated forward bias current.

Hence, photodiodes are preferably used in the reverse bias condition for measuring light intensity.