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Junction diode - unequally doped sides

  1. Jul 15, 2012 #1
    Why does the depletion layer penetrate a lightly doped side of a p-n junction diode?? Consider that there is a lightly doped p-side and a heavily doped n-side in a p-n junction diode , which is connected to a dc power supply in reversed biased. Now, i've read that depletion layer penetrates the p-side in this case. But i could not figure out the reason behind it. So, Can u please explain me the mechanism involved in terms of the movement of electrons in the circuit.
    Im in a faulty assumption that the side in which the diode is more heavily doped is bound to be penetrated more by the depletion layer..
    (-I've completed my intermediate)
     
  2. jcsd
  3. Jul 15, 2012 #2

    mfb

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    The sum of electrons and holes stays constant (the whole thing does not get a significant net charge). If the hole density is larger, the volume with holes is smaller, and vice versa.
     
  4. Jul 16, 2012 #3
    ok,, but i dint get the answer to my question!
     
  5. Jul 17, 2012 #4

    mfb

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    In this case, I don't understand the question. You have depletion at both sides as electrons from one side move into the holes at the other side, unless your diode is in a conducting mode.
     
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