Solar cells - how do they repeat the process?

In summary, solar cells convert sunlight into electricity through the movement of electrons from the N-type to the P-type. The external circuit replenishes the electrons and holes, allowing the process to repeat. Without a complete circuit, there would be no current flow.
  • #1
Emily0203
2
1
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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  • #2
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).
 
  • #3
Electric current flows in a closed loop, so the wire that carries electrons away from one side brings them back to the other.
 
  • #4
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
 

1. How do solar cells convert sunlight into electricity?

Solar cells use a process called the photovoltaic effect to convert sunlight into electricity. The photovoltaic effect is a process in which photons from sunlight knock electrons in the solar cell's semiconductor material loose, creating an electric current.

2. What materials are used to make solar cells?

The most commonly used materials for solar cells are silicon, cadmium telluride, and copper indium gallium selenide. These materials are chosen for their ability to efficiently convert sunlight into electricity.

3. How do solar cells repeat the process of converting sunlight into electricity?

Solar cells repeat the process of converting sunlight into electricity every time photons from sunlight strike the cell's surface. As long as the sun is shining, the photovoltaic effect will continue to create an electric current in the solar cell.

4. How efficient are solar cells at converting sunlight into electricity?

The efficiency of solar cells can vary depending on the type of material used and the conditions they are subjected to. Currently, the most efficient solar cells can convert up to 23% of sunlight into electricity, while the average efficiency is around 15-20%.

5. How do solar cells store the electricity they generate?

Solar cells do not have the ability to store electricity on their own. Instead, the electricity they generate is fed into a battery or power grid for storage and later use. This allows for a continuous supply of electricity even when the sun is not shining.

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