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Q & A: Why reverse bias a photodiode?

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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)

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