B Solar cells - how do they repeat the process?

AI Thread Summary
Solar cells operate through the interaction of N-type and P-type materials, where N-type has excess electrons and P-type has holes. When sunlight strikes the solar cell, it excites electrons in the N-type, allowing them to fill the holes in the P-type, generating electricity. The process can repeat because an external circuit replenishes the electrons on the N-side and the holes on the P-side, maintaining the flow of current. Without a complete circuit, there would be no current flow across the internal structure of the cell. Understanding this cycle is crucial for comprehending solar cell functionality.
Emily0203
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Hey everyone,
I have to do this presentation about solar cells and how they work. I've been doing a lot of research, and now I know a lot about how they work. However there is just one thing, that I can't understand.

So in a solar cell there is an N-type and P-Type. The N-type has too many electrons, and the P-type has these holes. When the sun shines on a solar cells, it strikes the electrons in the N-type out, and the electrons fill out holes on the P-type. And electrons that moves are what we know as electricity.

But when all of the electrons move to the P-type and fills out the holes, how does the solar cell repeat the process when there aren't any more free electrons on the N-type and the holes on the P-type has been filled with the free electrons?
 
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A solar cell is way more complex then the model you described. However, in the same framework, I'd say the external circuit (the solar cell charges a battery) takes care of "replenishing" the "sea" of electrons (N side) and holes (P side).
 
Electric current flows in a closed loop, so the wire that carries electrons away from one side brings them back to the other.
 
Emily0203 said:
So in a solar cell there is an N-type and P-Type. The N-type has too many electrons, and the P-type has these holes. When the sun shines on a solar cells, it strikes the electrons in the N-type out, and the electrons fill out holes on the P-type. And electrons that moves are what we know as electricity.

But when all of the electrons move to the P-type and fills out the holes, how does the solar cell repeat the process when there aren't any more free electrons on the N-type and the holes on the P-type has been filled with the free electrons?
marcusl said:
Electric current flows in a closed loop, so the wire that carries electrons away from one side brings them back to the other.
yes, exactly

no compete circuit outside the cell, no current flow across the internal structure of the cell
 
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