Dear Leonardo and Javier,
Many thanks for your helpful guides.
Best
Zara

On Fri, Oct 20, 2017 at 2:22 PM, Javier Junquera <[email protected]>
wrote:

>
>  Dear Zara:
>
>  In addition to Leonardo’s answer, you can take a look to these papers:
>
>
>
>    1. *Band alignment at metal/ferroelectric interfaces: insights and
>    artifacts from first principles *
>    Massimiliano Stengel, Pablo Aguado-Puente, Nicola A. Spaldin, and
>    Javier Junquera
>    Physical Review B 83, 235112 (2011)
>    <http://dx.doi.org/10.1103/PhysRevB.83.235112>[ cond-mat/1103.0504
>    <http://arxiv.org/abs/1103.0504>]
>
>
> *First-principles calculation of the band offset at BaO/BaTiO3 and
> SrO/SrTiO3 interfaces *
> Javier Junquera, Magali Zimmer, Pablo Ordejón, and Philippe Ghosez
> Physical Review B 67, 155327/1-12 (2003)
> <http://dx.doi.org/10.1103/PhysRevB.67.155327>[ cond-mat/0210666
> <http://xxx.lanl.gov/abs/cond-mat/0210666>]
>
> Hope this helps,
>
>  Javier
>
>
>
> El 13 oct 2017, a las 22:17, Leonardo Fonseca <[email protected]>
> escribió:
>
> Dear Zara,
>
> In general you cannot obtain the barriers directly from the atomic
> potentials. The barriers you are talking about are between band edges,
> either a Fermi level/conduction band alignment or a conduction
> band/conduction band alignment when you are dealing with metal/dielectric
> or dielectric/dielectric interfaces, respectively. The stack potential is
> the reference energy against which you will find where the band edges (or
> Fermi level) are. You can either combine bulk calculations of each material
> combined with your interface calculation to obtain the location of the
> interface band edges (see Van deWalle, C.G., Martin, R.M.: Theoretical
> calculations of heterojunction discontinuities in the Si/Ge system. Phys.
> Rev. B 34, 5621–5634 (1986)) or you can plot a layer-by-layer PDOS which
> will give you the band alignment directly. Each method has its own
> limitations, so to be sure it is better to do both.
>
> I hope this helps.
>
> Leo
> Center for Semiconductor Components
> University of Campinas, SP Brazil
>
> 2017-10-13 12:24 GMT-03:00 Zara Nosh <[email protected]>:
>
>> Dear expert,
>>
>> In the resonance tunneling devices (RTD), there are 2 potential barriers
>> inside the conductor. My system shows NDR behavior in its IV curve and it
>> seems that it is  a RTD system.
>> I have plotted the voltage drop profile, ElectrostaticPot(V)
>> -ElectrostaticPot(0), however I couldn't find barriers.
>>
>> How can i visualize the potential barriers in my system?
>>
>> Also I don't know in which bias I have to look for the barriers? In the
>> peak or somewhere between peak and valley, or maybe everywhere it should be
>> appeared?
>>
>> I really appreciate your help.
>> Best wishes
>> Zara
>>
>>
> AAA
>
>

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