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P-N junction charge utilisation

  1. Apr 16, 2012 #1
    Hello,

    A depletion region forms instantaneously across a P-N junction. When N-doped and P-doped pieces of semiconductor are placed together to form a junction, electrons migrate into the P-side and holes migrate into the N-side. As such, in the depletion region, the P-side becomes negatively charged with respect to the N-side which is positively charged,

    If an external conductor is made to connect the P and N areas of the depletion region, then a current must flow as there is a potential difference between the N and P areas of the depletion region. The effect of such conductance is to cause the charge difference, in the depletion region, between the N and P doped materials to diminish.

    My question is, will the P-N junction spontaneously tend to replenish the charge difference between the P and N doped pieces and hence cause current to continuously flow in the external conductor? Alternatively, if the conductor is periodically attached and detached, will this allow the spontaneous formation of charge separation to be utilised to generate current?

    Regards, Tim.
     
  2. jcsd
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