Help Explain this? :S Semiconductors :S (1 Viewer)

wrxsti

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"If the battery is connected with the p-type material connected to the negative terminal of the battery and the n-type material connected to positive terminal no current will flow" Why is this so? shouldnt the P-type... since. well its got a positive hole should be connected to the negative?
 

alcalder

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P-type conductors, when neutral, have an excess of holes (due to the doping) which means when they are connected with an n-type inductor they become negatively charged at the junction because electrons drift on over to fill the holes.

The N-type conductor, likewise, when neutral has an excess of electrons (due to doping) and after these drift to the P-type over the junction, the N-type side becomes positively charged.

Connecting the P-type to the negative side of the battery means that electrons are trying to enter the negative side of the junction and are repelled. This is, in effect, a diode. Certainly, you could force a current in this direction but you would need a much greater voltage to overcome that repulsion and the resulting current would be small.
 

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