Dear Alonso Onofrio,<div><br></div><div> I know some works that estimate the band alignment of two semiconductor materials in a heterostructure using their band structure calculated for the respective bulk systems. Despite of this, in my opinion, the accurate way to do it is to build a "supercell" starting from one of these materials and adding the other one along an appropriate axis.</div>
<div> You have to take care to build a sufficiently large cell in order to prevent "communication" between the same material regions in neighbour cells. Probably, you will have also to relax atomic positions for the atoms "near" the interface.</div>
<div> After this, you may use the DOS projected on the atoms to get an idea of the gap evolution along the axis perpendicular to the interface. As you will see, the picture of an abrupt change of the band gap at the interface is not real despite being very useful in approximations like "effective mass".</div>
<div> Well, it is obviously a much more computationally expensive procedure, but I believe it is the reliable way to do it.</div><div> Perhaps, the reference Physical Review B 79, 241312 (R) (2009) could help you.</div>
<div> All the best,</div><div> Luis Ogando</div><div><br></div><div><br><br><div class="gmail_quote">2013/1/23 <span dir="ltr"><<a href="mailto:alonofrio@comcast.net" target="_blank">alonofrio@comcast.net</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div style="font-size:12pt;font-family:Arial"><font face="Arial" size="3">Dear Wien2K Users,</font><div style="font-size:12pt;font-family:Arial">
<br></div><div style="font-size:12pt;font-family:Arial">I am new to Wien2k and I need help with the following.</div><div style="font-size:12pt;font-family:Arial">I am trying to get the band alignment of two semiconductor materials. These are 2D slabs for which I performed separate calculations and now I would like to compare the band edges.</div>
<div><font face="Arial" size="3">I understand that the bands and Fermi energy are calculated with respect to the average electrostatic potential calculated in the </font><font face="Arial">interstitial region. For these slab systems the electrostatic potential is calculated at Z=0 and Z=0.5 (:VZERO) from this I should be able to get the work function as WF=VZERO-FER. </font></div>
<div><font face="Arial" size="3"><br></font></div><div><font face="Arial" size="3">Now my question, Is it possible to compare these two separate calculations by means of knowing the work funtion of both slabs? If so what would be the procedure to compare the band edges (VBM and CBM) for both materials making sure they are measured from the same reference?</font></div>
<div><span style="font-family:Arial"><br></span></div><div><span style="font-family:Arial">Thanks so much, any input or opinion is greatly appreciated.</span></div><div><span style="font-family:Arial">Alex Onofrio,</span></div>
<div><span style="font-family:Arial">Department of Physics</span></div><div><span style="font-family:Arial">Universidad de Los Andes</span></div><div><span style="font-family:Arial">Bogota, Colombia. </span></div></div></div>
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