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Homework Help: Solid State Devices - Energy Band Diagram, Mobility, Diffusivity

  1. Sep 28, 2009 #1
    1. The problem statement, all variables and given/known data

    http://img121.imageshack.us/img121/2910/ssphysucks.th.jpg [Broken]

    Stuck on 1d

    2. Relevant equations
    Na - Nd = p0

    p0 = nie(EF-Ei)/kT
    kT here is 0.0259 eV

    n0 = (ni)2/p0

    Nv = p0e(EF-EV)/kT
    Nc = n0e(EC-EF)/kT

    3. The attempt at a solution

    I have found:
    p0 = 3.6x1016
    ni = 2x106
    n0 = 1.11x10-4
    Ei-EF = 0.6116
    Ei = 0.715
    EF = 0.0979

    Nv = p0e(EF-EV)/kT = 1.58x1018
    Nc = n0e(EC-EF)/kT = 2.40x1018

    b) (I got this down, but no scanner.)

    p0/NV = 0.0222

    My problem here is I don't know how to calculate mobility at all I know that
    qt/m* = un
    But I do not know where to get q or t, and I am assuming I can use my index for GaAs for m*
    Last edited by a moderator: May 4, 2017
  2. jcsd
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