So far, all the sources I've found explain the photovoltaic effect in relation to p-n junctions when talking about solar cells (since that's what they're made out of), but I was wondering if one could explain the photovoltaic effect in general without having to explain what p-n junctions are, as if it is only observed in them.
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There are also vacuum photocells with multi-alkali photocathodes. – Dec 10 '16 at 00:11
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Oooooh, nifty. It's a pretty interesting field, and I've just started looking into it. – 1234567 Dec 10 '16 at 00:14
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Another example of a system that exhibits photovoltaic action is a metal-semiconductor junction, or a Schottky junction.
In general photovoltaic action will occur at an interface involving a semiconductor. At this interface, say the interface between an n and p doped semiconudctor, there is an inherent asymmetry that causes electrons to want to go one way and holes to go the other.
Lee Aspitarte
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Thanks a lot, man. And yeah, there's another thing I didn't see being detailed, what actually causes the electrons to move from one material to the other, could you please tell me? – 1234567 Dec 10 '16 at 22:05
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In the case of the pn junction, a depletion layer will form at the interface between the n and p semiconductors. There will be an electric field in the depletion region that causes the separation of photo-generated electrons and holes. If you want to understand why this depletion layer forms...well, we are getting into the basics of semiconductor devices and if you want really meaningful answer you will need to read a good resource. This looks good. – Lee Aspitarte Dec 11 '16 at 08:19
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So unless they're connected to an external circuit, there would be no current. I see, I see, very interesting. Thanks again. – 1234567 Dec 11 '16 at 15:43