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Exciton is electron-hole pair

  1. Oct 1, 2009 #1

    I always heard my lecturer mentioned about 'less than 1 exciton'. as everybody knows, exciton is electron-hole pair. can we have <<<1 exciton??? What does it mean?
    thanks in advance for your reply.
  2. jcsd
  3. Oct 3, 2009 #2
    Re: exciton

    Are they referring to less than 1 exciton per unit cell? A small number of excitons in a large crystal would be much less than 1 exciton per unit cell.
  4. Oct 4, 2009 #3
    Re: exciton

    How do you expect anyone to answer this without more context?
  5. Oct 4, 2009 #4
    Re: exciton

    thanks for the replied.
    sorry for lack of information.

    it's about exciton in quantum dot (more specificly is in type-II quantum dot where the holes is confined in the dots). from photoluminescence of power dependence, they found 2 different slope by plotting the graph of QD peak vs laser power. at low power, the slope is small due to <<<1 exciton in dots. at high power, the slope is high (starts to have biexciton). however, this can be confirmed by doing photoluminescence in magnetic field.

    i am not understand the terms of '<<<1 exciton' (where from the definition, e-hole = exciton. i reckon 1exciton=1 pair of e-hole).

    would appreciate for a reply.
    thanks very much
  6. Oct 9, 2009 #5
    Re: exciton

    Likely, what is mentioned by your lecturer is what was said by kanato:)
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