Specfic question about the formation of the depletion region in a pn junction

Discussion in 'Physics' started by epsilonjon, Aug 2, 2012.

  1. epsilonjon

    Thread Starter Member

    Feb 15, 2011
    Hi. I am reading about the pn junction, but I have a question.

    When the junction is formed the holes in the p-type material close to the junction diffuse across due to the concentration gradient. This leaves the acceptor atoms in the p-type material negatively charged.

    My question is: when the holes diffuse across from the p-type, are they being filled by electrons from the n-type valence band, or are they being filled by the electrons in the donor atoms of the n-type material (whose energies are close to the n-type conduction band) who are diffusing in the opposite direction?

    Thanks! :)
    Last edited: Aug 5, 2012