The discussion revolves around the chemical potential of electrons in semiconductors, specifically whether it is constrained to values between the valence band maximum and conduction band minimum, and the conditions under which it might exceed these bounds. The scope includes theoretical considerations and definitions related to semiconductors.
Participants express differing views on the definition and characterization of semiconductors, indicating that multiple competing perspectives remain without a clear consensus.
There are limitations in the discussion regarding the definitions of semiconductors and the applicability of band structures, as well as the lack of specific examples or references to support claims made by participants.
DrDu said:It probably depends on how you define a semiconductor. Even a band structure is just a theoretical construct which does not correspond to a measurable quantity. I think there are substances whose resistance decreases with temperature and are thus semiconductors which are not well described in terms of a band structure.
DrDu said:No, but I had in mind Landaus- Fermi Liquid theory and some work of W. Kohn from 1964 where he tries to work out what fundamentally makes up a metal.