[Wien] about the nitrogen 2p states

[Andrei Postnikov]

On Fri, 7 Nov 2003, Yushan Wang wrote:

|
| Dear users,
|
| in nitrogen doped TiO2, I found the N - 2p states are pinned at the fermi
| level, which make the fermi level inserts into the valence band. this
| results is not reasonable because the N doped TiO2 is still a
| semiconductor.

OK, if you say it is still a semiconductor in the exp. -
in which limits of doping?
And what happens with the structure?
Is it still perfectly stoichiometric, or does it has deficiency?
You see that if you just substitute O with N, your system wants
to become a  metal. So, if the nature makes it a semiconductor,
there must be some special mechanisms
(deficiency, impurities, magnetism? - whatever) to achieve this.

And what do you exactly simulate as "nitrogen doped TiO2",
do you take a single cell?? - or a supercell? How big one? -
and substitute how many oxygens by nitrogen?

And how does this relate to what is known about the real system
which you say is semiconducting?

Andrei Postnikov

 +-- Dr. habil. Andrei Postnikov ----- Tel. +49-541-969.2377 -- Fax .2351 ---+
 | Universitaet Osnabrueck - Fachbereich Physik, D-49069 Osnabrueck, Germany |
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