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Indirect band gap semiconductor doubt

  1. Sep 18, 2010 #1
    indirect band gap semiconductor doubt

    its said that indirect band gap semiconductors like silicon and germanium are not used as a light sources because they have more non-radiative recombinations rather than radiative ,which inturn decreases efficiency of optical source.

    but i want to understand how indirect band gap materials produce non-radiative photons.

    i have studied many books like keiser , senior on optical fibre .those all are not explanatory on this ....also googled for this ,but not helped from there.....

    hoping for help here....thanks.....love to all....

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  2. jcsd
  3. Sep 19, 2010 #2


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    Re: indirect band gap semiconductor doubt

    The answer is that they do not produce non-radiative photons. There are a few radiative photons produced, but the majority of recombinations will result in phonons (lattice vibrations) and heating of the semiconductor. My semiconductor physics is a little rusty, but I think that Auger recombination is the phrase you're looking for.

    The book I used for my condensed matter physics (which covered this) was Kittel's Introduction to Solid State Physics.
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