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1

General Questions and Answers / Scf calculation of device IV not converged for higher electrode voltage

« on: April 11, 2018, 16:29 »

Hi,
I need a help from quantumwise experts.
When I do a device calculation with Gold as electrodes and MoS2 as channel with a dielectric of k=4 and a metallic gate of 0.5 volt, the scf calculation is not converged when I apply a electrode voltage of 2 volt or higher than 2 volt. There is no problem in convergence upto 1.75 volt. For higher voltage greater than 1.75 volt I am facing the convergence problem.
So please help me in this issue. I appreciate you for your valuable suggestion.
Regards,
Jayanta

2

General Questions and Answers / convergence problem in device with metallic gate and dielctric

« on: March 18, 2018, 11:04 »

I am facing a problem in ATK when I am using a metallic gate and dielectric into a device with gold as right and left electrodes and MoS2 monolayer as a channel material. When I calculate zero bias transmission spectra and I-V characteristics of two terminal device that is without adding metallic gate and dielectric the calculation is converged and I get I_V curve. But when I add a metallic gate with gate voltage -1volt and dielctric of dielectric constant=4 then some points are not converging. And when I change the dielectric constant to a value of 9 and 25 then no points are converging and my calculation stops.
I have done same calculation with DTB molecules as a channel and also test for graphene with adding gate and dielectric then there is no problem in calculation and I have got I-V curve correctly.
So is there any problem with MoS2 in ATK?
Please help me in this issue.