Thus the process creates the
possibility of conduction due to electrons in conduction band as well as
due to vacancies in the valence band Let us consider what happens in the case of Si or Ge crystal containing
N atoms For Si, the outermost orbit is the third orbit (n = 3), while for Ge
it is the fourth orbit (n = 4) The number of electrons in the outermost
orbit is 4 (2s and 2p electrons)