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Homework Help: Calculating Fermi Level position in doped Silicon

  1. May 5, 2012 #1
    Estimate the Fermi level position EFn for a Si sample at room temperature that
    is doped with 1015 shallow donors cm-3.

    From coursework I've gatherred over the year I understand the equation needed is: EF=EC-kT ln(NC/n)
    n, being equal to the donor concentration
    EC is the conduction band energy.

    my problem with the question is knowing the value of EC. I know the value of the bandgap for silicon but I can't relate it to EC without introducing EV, another variable I don't know. Any help with finding EC or another approach to the question would be great.
  2. jcsd
  3. Aug 9, 2012 #2
    If you assume Ec=0 eV... then the Fermi level will be reference to the conduction band edge (Ev would then be -Eg, since Eg = Ec - Ev).
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