Why Reverse Bias a Photo Diode?

why is it compulsory to make a photo diode reverse biased?
- Anonymous

It's because if the diode is forward biased it will conduct a lot of current and you can't detect the small amount of excess current produced by the photoelectric effect.   When the diode is reversed biased, no ordinary current flows and the detection of the photo-current is much easier.

LeeH

(published on 11/16/2009)