<div dir="ltr"><div><div><div>Dear Professor Gironcoli,<br><br></div>Thank you for your time.<br><br></div>Sincerely, <br><br></div>Dae Kwang Jun<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Jun 6, 2016 at 7:51 PM, stefano de gironcoli <span dir="ltr"><<a href="mailto:degironc@sissa.it" target="_blank">degironc@sissa.it</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div>if a dipole layer develops at the
interface (likely to occur when you put together atoms with
different charges and electro-negativity) a step in the
electrostatic potential would result... which directly shifts your
band-offset.<br>
think of how you can modify the workfunction of a surface (which
is the band offset between the material and vacuum) by adsorbing
polar molecules or anything that create a dipole layer.<br>
<br>
interface interminxg dependence in heterovalent junctions have
been studied extensively (among many others) by Maria Peressi. You
may wont to read some of her works starting with<br>
<br>
1.<br>
Band engineering at interfaces: theory and numerical experiments<br>
By: Peressi, M; Binggeli, N; Baldereschi, A<br>
JOURNAL OF PHYSICS D-APPLIED PHYSICS Volume: 31 Issue: 11
Pages: 1273-1299 Published: JUN 7 1998<br>
<br>
2.<br>
LOCAL INTERFACE COMPOSITION AND BAND DISCONTINUITIES IN
HETEROVALENT HETEROSTRUCTURES<br>
By: NICOLINI, R; VANZETTI, L; MULA, G; et al.<br>
PHYSICAL REVIEW LETTERS Volume: 72 Issue: 2 Pages: 294-297
Published: JAN 10 1994<br>
<br>
3.<br>
TUNING BAND OFFSETS AT SEMICONDUCTOR INTERFACES BY INTRALAYER
DEPOSITION<br>
By: PERESSI, M; BARONI, S; RESTA, R; et al.<br>
PHYSICAL REVIEW B Volume: 43 Issue: 9 Pages: 7347-7351
Published: MAR 15 1991<br>
<br>
HTH<span class="HOEnZb"><font color="#888888"><br>
<br>
stefano <br></font></span><div><div class="h5">
<br>
<br>
On 06/06/2016 12:37, Dae Kwang Jun wrote:<br>
</div></div></div><div><div class="h5">
<blockquote type="cite">
<div dir="ltr">
<div>
<div>
<div>Dear Professor Gironcoli,<br>
<br>
</div>
Thank you for your time. I do not think I understand the
dependence of the band offset in the interface. From what I
understand, band offset calculations are obtained from the
average potential in the bulk region and bulk band edges (or
core levels). I have seen many journals that state the
interface structure is important, and I know they should be.
However, I do not know how the structure of the interface
affects the band offset if only the bulk band edges and bulk
average potetential are used to calculate it. Could you
recommend me a reference that explains this? Most references
that I have found show how defects and strain influence the
band offset but do not explain why. <br>
<br>
</div>
Thank you in advance,<br>
<br>
</div>
Dae Kwang Jun<br>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Sun, Jun 5, 2016 at 5:21 PM, Stefano
de Gironcoli <span dir="ltr"><<a href="mailto:degironc@sissa.it" target="_blank">degironc@sissa.it</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">...
However in the case of band lineup between heterovalent
material band offset is strongly dependent on details of the
interface.. So I don't know how meaningful the calculation
can be.<br>
<span><br>
stefano<br>
(sent from my phone)<br>
<br>
</span>
<div>
<div>> On 05 Jun 2016, at 10:17, Stefano de
Gironcoli <<a href="mailto:degironc@sissa.it" target="_blank">degironc@sissa.it</a>>
wrote:<br>
><br>
> I think one could use the electric field option
putting a dipole layer deep in the bulk of one of the
two materials (maybe the metal) and monitor when the
macroscopic average of the electrostatic potential is
horizontal in the oxide to obtain the electrostatic
lineup.<br>
><br>
> stefano<br>
> (sent from my phone)<br>
><br>
>> On 05 Jun 2016, at 07:29, Dae Kwang Jun <<a href="mailto:jdaekwang@gmail.com" target="_blank"></a><a href="mailto:jdaekwang@gmail.com" target="_blank">jdaekwang@gmail.com</a>>
wrote:<br>
>><br>
>> Dear all,<br>
>><br>
>> I am trying to find the band offset between a
polar metal oxide and a metal. Is it possible to make a
dipole correction without any vacuum in the superlattice
or supercell?<br>
>><br>
>> Sincerely,<br>
>><br>
>> Dae Kwang Jun<br>
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