[Wien] Impurity level

[Lyudmila Dobysheva]

On Tuesday 22 February 2005 13:59, mkhsabra at aec.org.sy wrote:
> I have plot the band structure with character. I found that many atoms
> contribute to the lowest band in the conduction, one of them is the Si
> atom, even its contribution is less than the others. So can I say that this
> band is the Impurity level.

There should be some lines that are localized at Si atom and only in small 
extent at other atoms, and I'd call them "the impurity level". The lowest 
band is usually almost totally of s-character which is spread over the whole 
cell and contribution to it is given by almost all atoms proportionally to 
their number. Look at 
Figure 3.16: Bandstructure of TiC, showing t2g-character bands of Ti.
Compare it with 3.15 - simple bandstructure.
You should obtain something like this for Si for s- and p- electrons.

Best regards
  Lyudmila Dobysheva 
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