photodiode

Discussion in 'Homework Help' started by vultac, Apr 20, 2009.

  1. vultac

    Thread Starter Active Member

    Mar 2, 2009
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    could someone explain to me how does a photodiode work? I read article but i still don ge tthe n junction and stuff... what does it mean it works reversed biased?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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  3. Audioguru

    New Member

    Dec 20, 2007
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    A photodiode can work in two ways:
    1) When it is reverse-biased then light causes it to leak current. The reverse bias voltage causes its capacitance to be less so it switches fast. It has a temperature-dependent leakage current that is called "dark current".
    2) Without bias voltage then it is a tiny solar cell which produces a tiny current when it receives light. It is slower but has no dark current.
     
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