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Homework Help: Charge density, carrier concentration, or Hall coefficient for Indium Arsenide?

  1. Yes.

    2 vote(s)
  2. No.

    1 vote(s)
  1. Mar 29, 2008 #1
    I've been searching for an acceptable value for the charge density of indium arsenide; that is, the amount of charge per cubic meter. I have been unable to find anything.

    I'm working on a replication of the Hall Effect, and I need an accepted value for comparing my own results. I've searched Google multiple times, and have searched article databases from http://library.mtsu.edu/ ... It seems no one is very interested in something this mundane; it's all semiconductors and "quantum dots" and other complex esoteric material...

    Where else and for what else can one search? ... I've also not been very successful in ascertaining a clear definition of the Hall coefficient; it appears to vary, depending on the type of semiconductor, and whether one is addressing quantum or classical effects ... but one definition I have that I think is valid is simply the reciprocal of the charge density, that is, R = 1/(ne), where n = # of charge carriers / cubic meter (I think some call this the carrier concentration or carrier density; is that correct?)

    Any help or feedback is greatly appreciated.

    Sorry; the poll was meant to ask about the Hall effect... can't find where to edit (or recreate) the poll.
    Last edited: Mar 29, 2008
  2. jcsd
  3. Mar 29, 2008 #2
    This may be stupid, but unless this material is very exotic I would guess it is electrically neutral, in which case it has no net charge density? If so, then I guess what you really want is the mass density, because if you knew that and its crystalline structure then you could make a decent guess as to how many electrons or protons would reside within a given volume, right? With the doping data I guess you could figure out the mobile charge density also?
  4. Mar 30, 2008 #3
    Yes, I have thought about estimating from its molecular density, and this is what I will do if I cannot find an accepted value... and yes, it is of course electrically neutral, but that doesn't solve my problem. By charge density, or carrier concentration, I mean specifically

    r (Greek 'rho') = ne = (# of carriers of charge / unit volume) * (charge of each carrier) = net amount of negative charge / unit volume.

    Is that clear? Sorry if there was any ambiguity. One definition I've seen for the Hall coefficient is then

    R = 1/(ne),

    sometimes with a minus sign, so that R > 0.
    Last edited: Mar 30, 2008
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