Author Topic: Capacitance-Bias Variation  (Read 3711 times)

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Offline sergio

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Capacitance-Bias Variation
« on: March 17, 2015, 20:50 »
Hi,
I have followed http://quantumwise.com/publications/tutorials/item/511-calculation-of-atomic-scale-capacitance
to reveal the Capacitance -Bias variation of a device structure. Using the mulliken-analysis, for my device, I have obtained the capacitance as +1.54625e-20 Farad. But when I have plotted Capacitance-Bias variation it gives a negative capacitance varying from approximately -2.0e-20 to -1.54625e-20. So it is almost bias independent and converged to the capacitance that I have obtained. But the variation is negative but should be positive, what is the mistake here? Thanks for your help.

Offline sergio

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Re: Capacitance-Bias Variation
« Reply #1 on: March 24, 2015, 21:09 »
Hi,

Sorry, is there anybody who can solve the problem that I have encountered?

Thanks,

Offline kstokbro

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Re: Capacitance-Bias Variation
« Reply #2 on: April 1, 2015, 11:42 »
You have some sign error, possibly because you need to multiply mulliken population with -e to get the charge?

Offline sergio

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Re: Capacitance-Bias Variation
« Reply #3 on: April 2, 2015, 19:10 »
Hi,

Thanks for your reply. Yes, it is a sign error. But I have directly followed your script where -e is used. Thus I must get a positive variation but I have obtained a negative one.