Author Topic: Silicon Nanowire FET  (Read 3725 times)

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Offline Hassan

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Silicon Nanowire FET
« on: August 21, 2014, 00:14 »
Hi,

I simulated  Silicon nanowire FET with DFT-GGA. However, the currents that I'm getting are way too low I think.

I am attaching the structure of the FET.

I have also attached the Gate voltage vs. Current curve. The current being this low is basically just noise. Note, this data is from TransmissionSpectrum with -2eV to 2eV range. I redid the calculation with -4eV to 4eV range and the result is only an order of magnitude higher. It still produces extremely low currents.


Offline F. Fuchs

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Re: Silicon Nanowire FET
« Reply #1 on: August 25, 2014, 10:22 »
Looks like your electrodes are semiconducting and therefore no noteworthy current is possible.

You should consider doping your electrodes. Either by using real dopants or by using the charge keyword available in ATK (if you have a new version of ATK, you should also use http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.atomiccompensationcharge.html as pointed out in this forum somewhere else.). The latter is also used in the Si-NW-FET tutorial.

Offline Hassan

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Re: Silicon Nanowire FET
« Reply #2 on: August 25, 2014, 23:51 »
I have doped the electrodes, I still get negligible current. I have tried doping at 4e19 cm^-3, I think that's a pretty high doping. This is again with the Silicon Hydrogen-terminated NW.

Offline Umberto Martinez

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Re: Silicon Nanowire FET
« Reply #3 on: August 26, 2014, 08:38 »
How did you add doping? can you please upload the input script?
In you first attachment you reported only the configuration.

Also, did you compare with the tutorial "Simulation of a Si (100) nanowire FET"?
http://quantumwise.com/documents/tutorials/latest/NanowireDevice/index.html/chap.nanowiredevice.html