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Homework Help: Electron and hole concentrations

  1. Aug 14, 2010 #1
    Are the following formulas the correct solution to this question? Thanks in advance for any help!

    1. The problem statement, all variables and given/known data

    Write down equations for the electron and hole concentrations n and p in a semiconductor, in terms of [tex]N{c}[/tex] or [tex]N{p}[/tex], the Fermi level position [tex]E{f}[/tex] and the temperature, T.


    2. Relevant equations



    3. The attempt at a solution

    n= [tex]N{c}[/tex]exp[-([tex]E{c}[/tex]-[tex]E{f}[/tex]) / kT]

    n=electron
    [tex]N{c}[/tex]=Number of energy levels, conduction
    [tex]E{c}[/tex]=Energy levels, conduction
    [tex]E{f}[/tex]=Fermi energy levels
    k=Boltzmann's constant
    T=Temperature


    p= [tex]N{v}[/tex]exp[-([tex]E{f}[/tex]-[tex]E{v}[/tex]) / kT]

    p=holes
    [tex]N{v}[/tex]=Number of energy levels, valence
    [tex]E{v}[/tex]=Energy levels, valence
    [tex]E{f}[/tex]=Fermi energy levels
    k=Boltzmann's constant
    T=Temperature
     
    Last edited: Aug 15, 2010
  2. jcsd
  3. Aug 15, 2010 #2
    Looks fine to me, although I would have said [itex]E_c[/itex] is the energy level of the bottom of the conduction band. And vice-versa for [itex]E_v[/itex]. Also, the [itex]n[/itex] is concentration and not number (although you never specify).
     
  4. Aug 15, 2010 #3
    Thank you Nickjer, you've been a great help!
     
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