Solar cells - how do they repeat the process?

Click For Summary

Discussion Overview

The discussion centers around the functioning of solar cells, specifically the processes involving N-type and P-type materials, and how the flow of electrons is sustained during operation. The scope includes conceptual understanding and technical explanation of solar cell mechanics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant describes the basic operation of solar cells, noting the roles of N-type and P-type materials and the movement of electrons when exposed to sunlight.
  • Another participant suggests that the external circuit replenishes the electrons and holes, implying a continuous process despite initial electron movement.
  • A third participant emphasizes that electric current flows in a closed loop, indicating that electrons are returned to the N-type side from the external circuit.
  • There is a reiteration of the initial question about how the process repeats once electrons have moved to fill holes, suggesting confusion about the internal workings of the solar cell.
  • Some participants agree on the necessity of a complete circuit for current flow, while also noting that without an external circuit, there would be no current flow across the internal structure of the cell.

Areas of Agreement / Disagreement

Participants express differing levels of understanding regarding the replenishment of electrons and holes in solar cells. While some agree on the role of the external circuit, others remain uncertain about the internal processes and how they sustain operation.

Contextual Notes

There are unresolved questions regarding the internal mechanisms of solar cells and the assumptions about electron movement and circuit completion. The discussion does not clarify how the solar cell maintains its function beyond the initial electron movement.

Emily0203
Messages
2
Reaction score
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?
 
  • Like
Likes   Reactions: Delta2
Physics news on Phys.org
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
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
Replies
1
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 13 ·
Replies
13
Views
4K
  • · Replies 3 ·
Replies
3
Views
6K
  • · Replies 4 ·
Replies
4
Views
7K
Replies
5
Views
3K
Replies
15
Views
2K
  • · Replies 2 ·
Replies
2
Views
4K
Replies
7
Views
3K