[Pw_forum] Fermi energy in doped material.

[Jiayu Dai]

Dear all,

As we know, the fermi energy of semiconductor can be placed anywhere in the band
gap. For intinsic semiconductor, the calculation using pw.x is in agreement with
it. But for doped semiconductor, for example, heavily doped semiconductor, the
fermi energy should shift into the conduction band or valence band(depend on the
type of doping), but the gap is always there. So, the question is: How could we
know the heavily doped semiconductor is a metal or semiconductor? Or, the fermi
energy calculated is not appropriate in this case?

Thanks a lot. 




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Jiayu Dai
National University of Defense Technology, P R China