Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

B Solar cells - how do they repeat the process?

  1. Nov 10, 2018 #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?
  2. jcsd
  3. Nov 10, 2018 #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).
  4. Nov 10, 2018 #3


    User Avatar
    Science Advisor
    Gold Member

    Electric current flows in a closed loop, so the wire that carries electrons away from one side brings them back to the other.
  5. Nov 10, 2018 #4


    User Avatar
    Science Advisor
    Gold Member

    yes, exactly

    no compete circuit outside the cell, no current flow across the internal structure of the cell
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?