The Fermi energy in these materials lies near the middle of the band-gap and moves toward the valence band edge as acceptors such as boron and aluminum are introduced, or moves toward the conduction band edge with the introduction of donors such as phosphorus.  The continuit
The Fermi energy in these materials lies near the middle of the band-gap and moves toward the valence band edge as acceptors such as boron and aluminum are introduced, or moves toward the conduction band edge with the introduction of donors such as phosphorus.  The continuity equation expresses the change in carrier concentration in them as a function of factors such as Auger [OH-zhay] recombination, generation-recombination, diffusion, and drift.  Having a zinc-blend or diamond crystal structure, their atoms are generally bonded to their four nearest neighbors.  Examples include cadmium telluride, indium antimonide and the most well-known non-elemental type, gallium arsenide.  FTP name these materials, including elemental germanium, that have properties of both insulators and conductors.
The Fermi energy in these materials lies near the middle of the band-gap and moves toward the valence band edge as acceptors such as boron and aluminum are introduced, or moves toward the conduction band edge with the introduction of donors such as phosphorus.  
semiconductors