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Homework Help: Stupid question about band gap of AlGaAs/GaAs

  1. Apr 23, 2010 #1
    how the conduction band offset varies with Al concentration?? what is the different?
  2. jcsd
  3. Apr 23, 2010 #2
    This is a very vague question. If you want specific numbers you will have to read journal articles on experiments that measure conduction band offsets. If you want a qualitative answer, you know AlAs/GaAs is a type I band offset, with AlAs having the larger band gap. And when you have GaAs/GaAs, there is no offset. So as you increase Al concentration, the CBO will increase all the way to the max CBO of AlAs/GaAs. To find the exact form of the increase in the CBO you need to read journals.
  4. Apr 24, 2010 #3
    let say for AlGaAs/GaAs/AlGaAs structure, why Al increases the conduction band offset in this case?

    do you have any suggestion about the link that i can access to the journal? There's a lot of them but need to pay.
  5. Apr 24, 2010 #4
    I just told you why Al increases the CBO. Since it increases the band gap, and you also know the initial % Al = 0 then CBO = 0 and the final % Al = 1 then CBO > 0. Therefore as you increase Al concentration you must increase the CBO.

    As for the journals, I can't help you there.
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