### Author Topic: I-V of graphene nanosheet  (Read 109 times)

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#### Monika srivastava

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##### I-V of graphene nanosheet
« on: May 27, 2021, 14:28 »
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
« Last Edit: June 1, 2021, 12:36 by Monika srivastava »

#### Petr Khomyakov

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##### Re: I-V of graphene nanosheet
« Reply #1 on: June 1, 2021, 12:04 »
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

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##### Re: I-V of graphene nanosheet
« Reply #2 on: June 1, 2021, 12:34 »

Please find the attachment of the script files

#### Petr Khomyakov

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##### Re: I-V of graphene nanosheet
« Reply #3 on: June 3, 2021, 01:14 »
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

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##### Re: I-V of graphene nanosheet
« Reply #4 on: June 3, 2021, 20:46 »
I have used two probe model for finding I-V