I-V of graphene nanosheet

[Monika srivastava]

Hello sir

Is the number of repetition in graphene nanosheet affects the current or threshold voltage in current-voltage characteristics observed by modeling a two probe device model.

As it is well known that threshold voltage is decided by the band gap observed in density of states of the material but still I am getting two different curves for two different repetition.  one having 7 repetition shows increment of current from zero bias while one having repetition 11 shows some negative values of current and then start increasing around 0.15 V

[Petr Khomyakov]

Could you post a script used for this calculation? For example, if your graphene ribbon is intrinsic and has no doped-graphene based or actual metal source/drain electrodes attached, then the IV characteristics will depend on the device central region length.

[Monika srivastava]

Thank you sir for replying


Please find the attachment of the script files

[Petr Khomyakov]

You would need to design proper electrodes when applying bias voltage, e.g., by doping source and drain, see an example on how to introduce doping in https://docs.quantumatk.com/tutorials/silicon_nanowire/silicon_nanowire.html (Section: Doping the Si(100) wire).

Also, you may consider using IVCharacteristics study object to do device calculations, see https://docs.quantumatk.com/tutorials/ivcharacteristics/ivcharacteristics.html.

[Monika srivastava]

I have used two probe model for finding I-V