Author Topic: a question about PLDOS  (Read 3721 times)

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Offline bubble

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a question about PLDOS
« on: November 10, 2017, 08:42 »
https://docs.quantumwise.com/tutorials/nisi2-si/nisi2-si.html

In the above tutorial, the last but one figure gives the PLDOS of a 'forward-bias' PLDOS (Vb=0.3V). One can see that in the bias window (energy bewteen eL and eR), there are no states in the right electrode (corresponding the area in the energy range eL-eR is black if z is larger than. e.g. 60 A).   However, the tutorial discussed that ' here the electrons do not have to overcome any potential barrier, so that the current will be higher. '

I want to know what states are used to carry these electrons? Since in the bias window, for the right electrode, it seems that there donot exist any states!

Thank you!
« Last Edit: November 10, 2017, 08:44 by bubble »

Offline Petr Khomyakov

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Re: a question about PLDOS
« Reply #1 on: November 10, 2017, 10:03 »
The calculation of the current is done at a finite temperature, meaning that there are electrons populating the conduction band states in the electrodes.

Offline bubble

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Re: a question about PLDOS
« Reply #2 on: November 10, 2017, 12:01 »
The calculation of the current is done at a finite temperature, meaning that there are electrons populating the conduction band states in the electrodes.
Hi, Petr, I upload the figure. You mean that the states indicated by the red arrows are used to deliver the electrons?

Offline Petr Khomyakov

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Re: a question about PLDOS
« Reply #3 on: November 10, 2017, 12:58 »
Yes, it is correct. I also notice that Si is doped with electrons, so that there exist additional carriers in the conduction band (i.e., for energies > e_R) to contribute to the current, compared to intrinsic Si.

Offline bubble

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Re: a question about PLDOS
« Reply #4 on: November 11, 2017, 08:56 »
Yes, it is correct. I also notice that Si is doped with electrons, so that there exist additional carriers in the conduction band (i.e., for energies > e_R) to contribute to the current, compared to intrinsic Si.

Thank you for your reply. Although I still feel the discussion is a little against my intuition. it seems that there is no better explanation for this so far.  Thank you! ;D

Offline Petr Khomyakov

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Re: a question about PLDOS
« Reply #5 on: November 11, 2017, 17:24 »
As a matter of fact, it is not really about intuition, as there is a mathematical formula behind of what I have said, see the  definition of the electric current in Notes in the ATK manual at https://docs.quantumwise.com/manuals/Types/CurrentDensity/CurrentDensity.html.