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

Why do extrinsic semiconductors behave intrinsically at high temperatures?

  1. Jun 22, 2012 #1
    Is it because at high temperatures quasi-all electrons due to the doping are in the conduction band such that only the intrinsic behaviour is left?

    Or is it something else?
  2. jcsd
  3. Jun 25, 2012 #2
    At high temperature the number of electrons in the conduction band (and holes in the valence band) due to thermal excitations (Fermi-Dirac statistics) is much larger than the number due to doping. You can then neglect the extra doped electrons/holes which takes you back to the intrinsic behavior.

    The criteria for this should be kT >> | E_F,intrinsic - E_F,doped |
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook