Why Reverse Bias a Photodiode?

Most recent answer: 01/27/2014

Q:
why photodiodes are connected in reverse bias only
- omkar (age 15)
mumbai
A:

Hello Omkar,

If the diode is reverse biased then the current through the diode is very very small.   When photons hit the diode they will ionize a few  atoms and will produce a small current which you can measure.   When you forward bias the diode it will conduct  lots of current and the addition of a few more additional electrons is small compared with the forward current.

 

LeeH


(published on 01/27/2014)