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QuantumATK => General Questions and Answers => Topic started by: bubble on November 10, 2017, 08:42

Title: a question about PLDOS
Post by: bubble 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!
Title: Re: a question about PLDOS
Post by: Petr Khomyakov 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.
Title: Re: a question about PLDOS
Post by: bubble 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?
Title: Re: a question about PLDOS
Post by: Petr Khomyakov 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.
Title: Re: a question about PLDOS
Post by: bubble 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
Title: Re: a question about PLDOS
Post by: Petr Khomyakov 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.