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Homework Help: Can anybody correct me if I'm wrong?

  1. Oct 13, 2015 #1
    1. The problem statement, all variables and given/known data
    When pn junction is reverse biased, the depletion layer grows and no current flows except for the little reverse current.

    2. Relevant equations
    But acceptor aions have one electron that they can spare if you give it a little energy, and that electron could be attracted from the field of the donnor ions. But why that kinda doesnt happen?

    3. The attempt at a solution
    Thats my statement: even though it appears that atoms from the N region have lost an electron and now in that place can go another, that electron exchange between the semiconductors have more to do with The fact that the electrons doesnt simply move to atoms with umcompensated charge (wich they do) they move to atoms that need an electron to complete theyr bonds with other atoms. And when electrons flow to the p region there are many of those atoms. But the donnor ions have 4 more vallence electrons wich is more than enough to complete theyr bonds with the Si atoms. And thats why i think current doesnt flow. Becouse the holes in the P region have more '' weight'' on these free electrons than the uncompensared +charge on the N region. Can someone correct me if im wrong?
    Last edited by a moderator: Oct 13, 2015
  2. jcsd
  3. Oct 13, 2015 #2


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    Staff: Mentor

    What's an "acceptor aion"? Ions have nothing to do with semiconductors...
  4. Oct 14, 2015 #3
    When electron from N region fall into one of the holes in P region, the atop that accepyed that electron now has one external electron wich give him negative charge(that atom becomes ionized and becouse it accepts one electron it is called acceptor ion. And the atom that gaved that eectron now hos one less electron (its positive charged and its called donor ion.
  5. Oct 14, 2015 #4
    Hey, can anybody help me, im trying to figure that out from weeks. Since on the N side of the junction donor ions are building (positive charge is building) why cant that field just attract the electrons from the acceptor ions( the same electrons that gaved the atoms from the P region their negative charge) What is happening there?? I cant proceed with my electronics without answering that question so i need help, please respond to me i need to figure that out
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