Messages

1

General Questions and Answers / Re: Energy zero of Transmission Spectrum of MoS2

« on: April 28, 2015, 16:43 »

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.

2

General Questions and Answers / Energy zero of Transmission Spectrum of MoS2

« on: April 28, 2015, 00:49 »

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

3

Scripts, Tutorials and Applications / Re: How I can get energies vs. k-values for a uniform k-mesh in the entire brilloine

« on: March 25, 2015, 02:30 »

Dear Andres,

Thanks for your reply.
I would like to use the same k-points for energy as I have used for total energy calculations.

Let's say I have used k-point sampling of (10,10,10) for total energy calculations. Is this the same as:
kpoints = MonkhorstPackGrid(10,10,10)?

4

Scripts, Tutorials and Applications / How I can get energies vs. k-values for a uniform k-mesh in the entire brilloine

« on: March 15, 2015, 23:01 »

Dear All,

I would like to have energies vs. k, for a uniform k-mesh in the brillouin zone. In bandstructure we have energies or eigenvalues vs. k-points along routes of brillouin zone, but I want to have eigenvalues for a uniform k-mesh in brillouine zone. This uniform k-mesh is being used for calculating DOS or total Energy, But I couldn't find any way to get what I want from those calculations.

Would you please let me know if there is any way to do it?

Best

5

Installation and License Questions / ATK-Classic not working on my ATK 2014.1 version

« on: October 15, 2014, 18:23 »

Dear ATK team,

I am a research assistant in George Mason university and we have bought the license. I have been using ATK13.8 without any problem. I just installed 2014.1 version and when I tried to use ATK-CLASSIC calculator, it gave me an error about my licensing.

Would you please help me out here? What should I do to fix this issue?

Best,
Abbas

6

General Questions and Answers / calculating Seebeck coeffient, thermal conductance, and ZT

« on: July 1, 2014, 21:12 »

Dear ATK team,

I have been trying to calculate Seebeck coeffient, thermal conductance, and ZT for MoS2, MoSe2, WS2 and WSe2 nanoribbons doped with As, for calculating phonon transmission spectrum when I use an ATK classical calculator it gives me the warning such as:

The brennerCalculator has no parameter for Arsenic.
The EMTCalculator has no parameter for Arsenic
The TersoffCalculator has no parameter for: Arsenic, Sulfur, Molybdenum.

I would like to know that if this problem has been addressed in any recent version of atk.

Thanks.

7

General Questions and Answers / Re: Self-Consistent and Linear I-V characteristics

« on: April 1, 2014, 16:36 »

applying voltage on electrodes not only shift the fermi level of right and left electrodes but also it changes the transmission spectrum rather substantially.
As far as what my results show, transmission spectrum strongly depends on teh applied bias on electrodes.

8

General Questions and Answers / Self-Consistent and Linear I-V characteristics

« on: March 31, 2014, 23:16 »

Dear Sir/Madam,

I am trying to get I-V cure of a monolayer MoS2 and I tried both Self-Consistent and linear methods. In Self-Consistent I have calculated transmission spectrum for every single bias point and consequently using that spectrum to calculate the current. In linear approximation I have calculated transmission spectrum in zero bias and insert the electrode voltages when I am calculating current.
It gave me two very different I-V curves.
I am wondering that transmission spectrum can be so sensitive to applied bias since I am applying a bias window from -0.8V to 0.8V ?

9

General Questions and Answers / three electrode device

« on: March 22, 2014, 23:29 »

Dear Sir/Madam

I am trying to make a three electrode device. The code gave me an error saying that "The parameter 'electrodes' must be a sequence containing exactly two BulkConfigurations". but in the manual it was said that we can define three electrodes. would you please let me know how I can define the third electrode?

Thanks