QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Ashley.amanta@gmail.com on June 19, 2018, 13:03

Title: InSe
Post by: Ashley.amanta@gmail.com on June 19, 2018, 13:03
Hi
I tried to create 4*4 InSe nanosheet, but when I want to set the K-points in the new calculator, number of symmetry reduced K-point is not available. please help me, what is the problem?
I attached structure and picture of new calculator
thanks
Title: Re: InSe
Post by: Ulrik G. Vej-Hansen on June 20, 2018, 11:10
The cell type has become "Unit Cell" during the process, which has no symmetries. You can change it in the Builder, using the Lattice Parameters tool in the right-hand menu.
Title: Re: InSe
Post by: Ashley.amanta@gmail.com on July 18, 2018, 09:05
Dear Ulrik G. Vej-Hansen
Thank you for your reply.
I have built InSe, the steps are as follow :
1. Open builder > from data base > InSe
2. Select right four atoms and delete them
3. Open coordinate tools > center > apply
4. From bulk tools > lattice parameters and chose lattice type = unit cell and keep = Cartesian
5. Go to script generator and optimize structure and relax it
6. Send relax unit cell to builder
7. Open bulk tools > lattice parameters > change lattice type to hexagonal
8. From bulk tools > repeat a=4 b=4
9. Send to script generator and set parameters
I want to know is it right?
Also, when I get band structure, according to other articles it is true, but for 4.4 InSe every thing is diffetent.
Please guide me.
I attached band structures
Thank you so much for your help.
Title: Re: InSe
Post by: Petr Khomyakov on July 18, 2018, 10:23
When you increase a unit cell for a bulk, periodic structure, you automatically reduce the corresponding unit cell (the Brillouin zone) in the reciprocal space. It means that the original bands are to be folded in the new unit cell Brillouin zone. This is why the band structure looks different, as it is plotted for this reduced Brillouin zone.
Title: Re: InSe
Post by: Ashley.amanta@gmail.com on July 20, 2018, 08:26
please tell me, how can I build a device InSe 4.4 hexagonal?!
Title: Re: InSe
Post by: Anders Blom on July 23, 2018, 09:51
Switch steps 7 and 8. Also, why step 4? If you want to keep the symmetry, why do you remove it on purpose?
Title: Re: InSe
Post by: Ashley.amanta@gmail.com on July 23, 2018, 21:44
Dear....
I want to design a transistor like:
Ho, Po-Hsun, et al. "High-mobility InSe transistors: the role of surface oxides." ACS nano 11.7 (2017): 7362-7370.
so, I followed these steps for designing InSe:
1. Open builder > from data base > InSe
2. Select right four atoms and delete them
3. Open coordinate tools > center > apply
4. From bulk tools > lattice parameters and chose lattice type = hexagonal and keep = Cartesian
5. Go to script generator and optimize the structure and relax it
6. Send relax unit cell to builder
7. From bulk tools > repeat a=4 b=4
as you can see in fig 1 I have an InSe sheet, but, unfortunately, I can not continue and build a device. please guide me
I attached a file and figure
Title: Re: InSe
Post by: mlee on July 30, 2018, 14:11
In order to build a device, you need a periodic structure in your bulk.
I repeated c=3 in the repeat of Bulk Tools in the Builder.(One periodic is for left electrode, another one is for central and other is for right electrode).
Then I did Device from Bulk in the Device Tools of Builder.
Please see the attachment.
I hope it is what you want.
Title: Re: InSe
Post by: Emre.Bolghon on July 30, 2018, 18:33
Hi all user
Dear, Ashley I have the same problem and I think with Software we could not design a hexagonal device.
and M.r Mlee, what is this? I think both of us( me and Ashley ) need a one-layered device, I don't know what is your device!!!!
Title: Re: InSe
Post by: mlee on July 31, 2018, 09:09
Do you want to build one layer device such an attachment?   
Title: Re: InSe
Post by: Ashley.amanta@gmail.com on August 1, 2018, 09:13
Dear mlee,
Yes, I want to build one layer device like this, I need a hexagonal device, please tell me how can I build this device?
Title: Re: InSe
Post by: mlee on August 1, 2018, 14:10
Great.
I attached how to build it by me.
But it depends on the customized way and design.
I hope it is helpful to build your device using my way.
Title: Re: InSe
Post by: Ashley.amanta@gmail.com on August 15, 2018, 15:35
Thank you so much for your reply, but I have another question, which step the structure should change to hexagonal?!
You did not say that and when I build the InSe by your way and change the structure to hexagonal I think the band structure become wrong!!
I attached band structures for InSe 4.4 and InSe 2.2.
Also, when I build a device as you have guided, K point is active in three directions, is it right?

Thanks for your response
Title: Re: InSe
Post by: Emre.Bolghon on August 17, 2018, 07:57
as told you by this software you can not analyze a hexagonal nanosheet :-\
Title: Re: InSe
Post by: Ulrik G. Vej-Hansen on August 17, 2018, 09:57
This is a ridiculous claim. We have plenty of tutorials showing how to analyze graphene in many forms. Please make a sketch of the device you want to create, if we are to help you create it.