Topics

1

General Questions and Answers / Introduce strain

« on: January 15, 2023, 14:08 »

I want to introduce strain to (1-D nanoribbon). I have read past discussion on strain in the forum and i get a little confused. I need help from expertise. Is this how strain is introduced ? (here i attach picture of before and after strain). Can expertise correct me if i do it wrong way.

From bulk tools:
-> lattice parameters (lattice type in "unit cell" and i keep "fractional coordinates")
-> repeat (i repeat along C-axes)
->stretch cell (i select all atom, and i did strain in A-axes by "moved" it ). Here i did strain 1%.

Do i need to include together optimize geometry under bulk calculation ?
Really appreciate anyone reply to this. Thank you.

2

General Questions and Answers / Why the curve does not showing like typical id vds characteristic of mosfet ?

« on: October 31, 2022, 05:54 »

I currently studying BC2N nanoribbon with back gate. I need help, i was wondering why the curve does not showing like typical id vds characteristic of mosfet.

Here are the settings I used:
-Lcao calculator
-left & right electrode in lcao calculator : 0V
-Multi-grid solver type, where (A & B) i put Neumann, and C i put Dirichlet.

Below i attached the side and front view of BC2N with back gate structure, and the id vds obtained. I appreciate any help and suggestions.

3

General Questions and Answers / Error occured

« on: October 24, 2022, 13:34 »

Im trying to run my simulation. After i send script to job manager, this messages of error popup. Can anyone guide me what should i do ?
I really appreciate it.

4

General Questions and Answers / Can we know the concentration used of the studied gas ?

« on: October 16, 2022, 18:35 »

Hi, i need help. Can we know the concentration used of the studied gas ? Is there any features on the specification for the concentration of the studied gas?

5

General Questions and Answers / Metallic in spatial region voltage

« on: September 16, 2022, 08:04 »

Hi, i was trying to design a device using bc2n with back gate. I have followed the tutorial and found about the setting for spatial region, please see picture below. Could you please explain to me about metallic voltage. Is there any ideal value to set for metallic voltage ? Is it okay to put 0V. I was trying to produce current vs gate-source voltage using Iv characteristic.

6

General Questions and Answers / Bending or twister

« on: September 6, 2022, 16:06 »

Hi,

Im using quantumatk version s-2021.06. How can i apply bending or twister on GNR ? On tutorial https://docs.quantumatk.com/tutorials/exploring_graphene/exploring_graphene.html , there is option for this.
Appreciate if anyone can guide me on this. Thankyou

7

General Questions and Answers / Back gate

« on: August 18, 2022, 21:38 »

Hi Sir,

will it possible if back gate is apply within the left and right electrode of, lets say graphene nanoribbon ? or does back gate must apply with source and drain only, which the analysis will be under IV characteristics ?
I really appreciate any advice and help on this

8

General Questions and Answers / Overlapping issue on mxene nanoribbon

« on: June 5, 2022, 03:28 »

Hi everyone, I really need help, im having issue about overlapping.
Im currently studying about mxene nanoribbon, Ti2CO2. To form Ti2CO2 nanoribbon, i tried to build it separately, which first i build C-Ti nanoribbon and then C-O nanoribbon. After that, i drag C-Ti nanoribbon onto C-O nanoribbon. The structure will look like below.

Before i proceed for running, there is prompt appears saying some atoms overlap and some atoms closer. Sir, is there any way for me to solve this overlap issue ? I want to produce bandstructure.

I really appreciate if you can help me on this.

9

General Questions and Answers / Charge transfer

« on: November 24, 2021, 20:21 »

Hi Sir,

Im currently studying about GNR for gas sensor. I have difficulty in interpreting and calculate charge transfer from mulliken population result.

I really need help and i appreciate any advice regarding this. Thankyou

10

General Questions and Answers / Adsorption energy

« on: November 17, 2021, 05:17 »

Hi Sir,

I am currently studying about GNR gas sensor and i wanted to find the adsorption energy. I need advice and want to clarify the procedure.

Procedure:
1. i build my structure --> run calculator and optimize geometry.
2. i repeat the structure along c direction and attach the gas at one of the atom (let say H2 gas at carbon).
3. send to calculator, add bandstructure, dos and total energy. I use LDA, FHI for pseudopotential and doublezetapolarized for basis set.

Is the procedure above correct Sir ? and Sir, is it acceptable for the value of total energy if it is too big ?

11

General Questions and Answers / Barrier height

« on: November 8, 2021, 09:44 »

Hi Sir,

I am simulating a schottky diode based on graphene. I want to find the barrier height before and after substitutional doping. I would like to ask if the barrier height can be obtain without simulating the i-v characteristic like using hartree different potential ?

12

General Questions and Answers / Log details not appear

« on: October 15, 2021, 08:02 »

Hi Sir,

I have been running this simulation last Saturday on 9 October 2021. May i know why the details of the log didn't come out until now ? This is because I cannot keep track the progress of the simulation.
Thanks.

13

General Questions and Answers / What is the unit for effective mass ?

« on: October 9, 2021, 09:35 »

Hi everyone,

I need a confirmation, is there any unit measurement for effective mass ? or it does not carry any unit ? or the unit for effective mass is actually as below picture i have attached. I appreciate and thank you so much if anyone can reply this. 

14

General Questions and Answers / How to set bond length distance

« on: October 3, 2021, 15:54 »

Hi everyone,
I am trying to built carbon doped boron nitride nanoribbon, i am trying to set the bond length to a specific distance. For example I want to set bond length carbon to carbon to 1.42 A , B to N to 1.45 A, carbon to N to 1.32 A and B to carbon to 1.55 A. I appreciate if anyone can guide me on this.
Thank you