The gang of 4

Discussion in 'General Science' started by studiot, Jan 5, 2009.

  1. studiot

    Thread Starter AAC Fanatic!

    Nov 9, 2007
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    Since we are debating enhancing the AAC book on transistor action it is worth look at the group IV elements in the periodic table.

    These are Carbon (C), Silicon, (Si), Germanium (Ge), Tin (Sn), Lead (Pb)


    How is it that they form tetrahedral crystals but

    Diamond is an insulator
    Silicon and Germanium are semiconductors
    Tin and lead are conductive metals

    Silicon dioxide, also covalent, tetrahedral is one of the best insulators known.

    How do we get from here to the solid state electronics industry?

    How does conduction differ in insulators, semiconductors and metals?
     
    Last edited: Jan 5, 2009
  2. Wendy

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    Actually Diamond is a semiconductor, since carbon falls in that class. Pure silicon is also an insulator, and has some characteristics in common with crystallized carbon (diamond mostly). I've been reading more than one article where diamond is being experimented with to make transistors. I've been following their progress with interest.

    The one over riding advantage of diamond is it is the best thermal conductor known to man, at least at room temperature. It has been used as a substrate for the electronics of several satellites for this reason.
     
  3. thingmaker3

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    Do carbon, silicon, and germanium readily form cations? Do they indulge in metallic bonding? Or are they somewhat more stingy with their valance electrons?
     
  4. loosewire

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    Gold is use in computers.
     
  5. Wendy

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  6. Wendy

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  7. someonesdad

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    I saw the title "Gang of four" and thought "Sheesh, maybe I've been wrong all these years and some EEs know some software engineering".

    False alarm. :)
     
  8. studiot

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    Actually the reference was to the Chinese leadership of some years ago and also to the founders of a now defunct political party in the UK. Both of whom were known as 'the gang of four'.
     
  9. ELECTRONERD

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    Good luck with the "diamond transistors"! Man, will those be expensive!
     
  10. beenthere

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    Graphene has quite possibly made diamond obsolete - except perhaps for thermal characteristics. What one form of carbon can do...
     
  11. Wendy

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    Actually the current cost of diamonds is pretty artificial. If a serious use came out tomorrow there are several techniques to synthesize real high quality diamond, probably semiconductor quality (similar to silicon ingots).

    http://en.wikipedia.org/wiki/Synthetic_diamond

    I remember seeing there is a small but growing market for synthetic diamond for some jewelry.
     
  12. beenthere

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    I can't give a link, but there is at least one outfit that will take your ashes and use them to produce a keepsake diamond for your spouse/kids. Making diamonds is pretty easy these days.
     
  13. ELECTRONERD

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    This is pretty interesting...so how well is graphene and diamond working?

    By the way...have you guys heard about the reversable diode? Some university constructed this diode that could be used in either polarity and that it also generated voltage when light was applied (so could be used in future solar panels). I don't know all the details though...
     
  14. Wendy

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    Using diode in either polarity? That sounds like a zener.

    Or a LED. It can produce light, or electricity.

    I don't know if diamond is conductive, probably like silicon it can do either. Diamond substrate with a graphine coating?
     
  15. beenthere

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    The structure of diamond does not conduct electricity, but it is one of the best thermal conductors available. That property makes it attractive for a substrate.
     
  16. DrNick

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    Dec 13, 2006
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    Diamond's structure can support conduction. However it must be doped appropriately (just like silicon) to forward bias the device. The conduction band is much wider (about 5.5 eV), so using it in low power low voltage integrated circuits may be a challenge when these devises become available.
     
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