Problem with values of drain current obtained at a certain range of gate voltage

[yz]

Hi all,

Im trying to find the IV characteristic of Schottky Barrier FET using nanoribbon. I have obtained a Id-Vg (drain current vs gate voltage) curve at a Vd (drain voltage) bias of 20mv using a range of Vg values from -4.2 to 2.4. However i have some problem with Vg values like -0.8,-1,-1.2,-1.4,-1.6. The Id values that i obtained from those values deviates very widely from the rest of the points in my Id-Vg curve. Is there any method or any parameter i should change im my codes for me to get the proper Id values at those points without such deviation?

I have attached the two files containing the codes used to generate my IV curve.

[Nordland]

If you have access to the newest ATK 2008.10, I would try using the new constraint DensityMatrix, which I have good experience with, when it comes calculations involving biases and gate voltage.

Otherwise, does the the system converge easily?

[yz]

For those range of Vg values that i have problem with, what i realize is that they take a very long time to finish the convergence.

Regarding the DensityMatrix, do you mean iterationMixing.DensityMatrix?