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Expression for the internal potential

  1. May 15, 2008 #1
    Any one has any ideas where can i find an expression for the internal potential that results in an isolated silicon sample...

    i know why this internal electric field is set up due to the space charge region.... having the diffusion process that tends to generate more space change and the electric field itself generated by the space chare that tends to counteract the diffusion....

  2. jcsd
  3. May 15, 2008 #2
    Potential with respect to what?
  4. May 15, 2008 #3
    basically when a silicon sample is isolated, there will be an internal electric field set up due to the space charge region ......now i need to derive an expression for this internal potential field..... im not sure what i should consider
  5. May 15, 2008 #4


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    Your question is unclear.
    Try describing your setup in more detail.
  6. May 15, 2008 #5
    Excuse me about that its my first time using this sort of help.... basically i have the following...

    first i have an n type silicon , and electrons are supplied to it to keep the concentration constant. and then the current density is found... by the data given are 2um long varies linearly from 10^17 at one end to 6 X 10^16. un(mobility) being 1000....

    now this silicon is isolated and explained that it will have an internal electric field and i need to figure out an expression for the internal potential and then i have to calculate it... i don t know what i should consider.... hopefully i made myself clearer.thanks
  7. May 16, 2008 #6


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    Better, but making oneself clear is a skill in its own right. :smile:

    Does your question involve something like this?

    If you are saying that the charge density is linear then I would imagine that that the field gradient would be linear as well, but I really have no idea if this applies to your question.
  8. May 16, 2008 #7
    Thanks for your help:) You actually did help me:) I guess you have a great skill :)


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