QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: Trung Phuc on June 20, 2018, 12:04
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Hi administrator!
From previous posts, I know that ATK can help users calculate band structure of electrode at zero bias voltage. However, after spending time reading manuals and tutorials, I do not know the way to calculate the band structure of the electrode in device at finite bias voltage. My configuration (attached below) is zigzag graphene nanoribbon passivated by P atoms.
I really want to find the solution for this issue because I plan to explain the changes of transmission spectrum of device when applying bias voltage by the transformation of electrode band structure.
Thank you so much for your help.
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The band structure of a device electrode does not change under finite-bias NEGF calculations, only the Fermi level is shifted because of the applied bias. In fact, the electrode electronic structure is calculated before the NEGF calculations starts, and is fixed for the entire NEGF calculations, also under finite bias (except for a possible shift of the Fermi level).
I suggest you use the ProjectedLocalDensityOfStates analysis to investigate the effect of biasing your device. See e.g. this tutorial:
https://docs.quantumwise.com/tutorials/inas_p-i-n_junction/inas_p-i-n_junction.html#band-gap-and-band-edges (https://docs.quantumwise.com/tutorials/inas_p-i-n_junction/inas_p-i-n_junction.html#band-gap-and-band-edges). Perhaps consider also consider computing the Voltage Drop: https://docs.quantumwise.com/tutorials/atk_transport_calculations/atk_transport_calculations.html#voltage-drop (https://docs.quantumwise.com/tutorials/atk_transport_calculations/atk_transport_calculations.html#voltage-drop)
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Dear Jess Wellendorff,
I understood the picture of electrode band structure. Your help is very meaningful to me.
Thank you very much!!!
Trung Phuc.