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Effective mass dependency on the donator atom?

  1. Jan 6, 2016 #1
    Hello pf
    Is the effective mass dependend on the donator atom in a semiconductor?
    In our experiment we have calculated the effective mass in a germanium semiconductor, doped with an unknown atom. It is 0.39m_e. From the internet we know that the effective mass is 0.33m_e.
    Is our result equivalent to the litterature value or does it depend on the donator?
    Kind regards Alex
  2. jcsd
  3. Jan 7, 2016 #2


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    First of all, it is called a "donor".

    Secondly, no, the effective mass is not dependent on the donor. The donor is "donating" either electrons or holes (although a "holes donor" is usually call an acceptor). These electrons and holes sit in the host semiconductor, not in the donor. So the band structure (the E vs k) that is relevant here is the host, not the donor. Since the effective mass depends on the curvature of the band structure, it means that the donor plays no role here.

  4. Jan 8, 2016 #3
    If the donor concentration is dilute (roughly ≤ 100 ppm) then it will not affect the band structure of the host and as such it will not affect the effective mass. On the other hand if the donor concentration is high it can impact the band structure of the host and the effective mass.
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