I'm having trouble grasping the concept of extrinsic/doped semiconductors. For example, suppose that the semiconductor is n-typed with a certain density of donors.
At room temperature, about 300 K, I understand that you can assume the donors to be fully ionized, which I interpret as all valence electrons are in the conductor band, leaving the donor band filled with holes. If this is correct, then there shouldn't be any holes in the valence band, right?
If I haven't understood it correctly, how do you find the electron and hole density at 300 Kelvin given a certain density of donors?