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Intrinsic Carrier Concentration for Carbon

  1. Feb 22, 2008 #1
    Hello everyone.
    Right now i'm learning about carbon electrical properties for my final assignment in college. But somehow i just can't find the intrinsic carrier concentration properties for carbon.

    I've found the graphics that show me the relationship between the intrinsic carrier concentration and temperature, but just for Germanium, Silicon and GaAs. Could someone help me with this problem ?

    Oh, and one more question. Does the electron affinity property for carbon nanotubes (CNT) is different from the original carbon ?
    I read that electron affinity is an invariant fundamental property of the specified material, so i wondered whether it'll be the same or not for carbon and CNT.

    Thanks in advance.
  2. jcsd
  3. May 20, 2015 #2
    It probably depends on the type of carbon you are talking about:
    graphene is a single layer of carbon it has a carrier concentration of around 10^10 1/cm^2 at room temperature
    graphite which is multiple layers of carbon stacked on itself (like in your pencil)
    Carbon nanotubes have carrier concentrations that very with the chirality and can range between appriximately 10^4 and 10^20 1/cm^3 depending if they are metallic or semiconducting
    Diamond I have no clue
    Then there are molecules like C60 and C70

    Off the top of my head I would say the electron affinity would change between the different forms of carbon. For instance in small diameter CNTs you have steric pressure that will change the electron clouds etc. Then look at diamond you have a very rigid tetrahedral structure that does not really conduct. Don't take my word for it though.
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