Energy zero of Transmission Spectrum of MoS2

[abbas]

Dear ATK team,

I calculated transmission  spectra of mono-layer and multi-layer MoS2 nanoribbons. In my transmission spectra, fermi level is not in the middle of bandgap. Did I do something wrong? I mean because these structures are semiconducting and I have not doped them, shouldn't the fermi level be in the middle of gap?

Best,
Abbas

[Umberto Martinez]

Please, attach script and provide more details.

[abbas]

I have attached the script generated by ATK for a device configuration of mono-layer MOS2 using Huckel calculator. I had not changed anything in the script.

I have also attached two figures for transmission spectra of mono-layer MOS2 and double-layer MoS2 nanoribbons. As you can see in transmission spectrum of monolayer device, fermi level is closer to valence band, while in double-layer it is closer to conduction band. I do not know why this is happening.

[Umberto Martinez]

At the moment there are no semiempirical parameters for MoS2 in ATK database. So I am not quite sure what you will get with that potential.
You will need to use ATK-DFT.