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Question regarding diodes

  1. Jan 28, 2005 #1
    I have a question regarding diodes. Aluminum has 3 valence electrons, and normally bonds with 3 atoms in order to rid itself of the valence electrons, right? Okay, but when mixed in a matrix of silicon atoms, it doesn't have enough electrons to share with the silicon. This makes a hole. Okay, but according to my books, this hole is swapped between the silicon atoms. It says the aluminum binds with three neighboring silicon atoms, and then it says that it steals one from the silion, in order to fill it's shell, well it's already filled, 3 neighbors!!!
    Help please.
  2. jcsd
  3. Jan 28, 2005 #2
    I've answered my question by myself, but thanks anyway.
  4. Jan 29, 2005 #3


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    The crystal lattice of silicon makes each atom bound to 4 neighboring atoms. If you diffuse an Al atom in the crystal, it will associate with 4 adjacent Si atoms. Since it has only 3 electrons to share, there is a hole.
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