Physics - Semiconductors Question with Solution | TestHub

A photodiode is a semiconductor device used to detect optical signals or light intensity. It is always operated in reverse bias. This is because in reverse bias, the fractional change in the minority carrier current due to incident light is much more measurable than the fractional change in the majority carrier current in forward bias. Therefore, a photodiode in reverse bias is used for detecting light intensity.

Answer: photodiode in reverse bias.