1
General Questions and Answers / Photoluminosence spectra calculation?
« on: August 29, 2021, 16:30 »
Is it possible to get PL spectra using quantumATK?
Show Posts
This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.
Pages: [1]
2
General Questions and Answers / Re: Query regarding calculation of capacitance using ATK
« on: January 9, 2021, 12:13 »
I am not trying to calculate the quantum capacitance. I just wanted the capacitance for the structure that is dependent on the interlayer distance between the bilayer system. But I am unable to perform calculations on a bilayer structure as when I transform it into a device configuration, more layers are added by the VNL. what should I do?
3
General Questions and Answers / Query regarding calculation of capacitance using ATK
« on: December 30, 2020, 16:49 »
I have a graphene bilayer structure whose capacitance I wish to find out using QuantumATK. I have made it into a device configuration with 6 layers and L-R electrodes I have followed the steps as given in the tutorial https://docs.quantumatk.com/tutorials/atomic-scale_capacitance/atomic-scale_capacitance.html for the calculation of atomic scale capacitance. And I am facing some problems and some queries that I wished to clarify.
1. When the capacitance is being calculated using the induced charge method (Mulliken charge), I am getting a very high value of the plate distance d. When viewed from the structure, the actual value of plate distance d = 10.26 Angstrom whereas from the induced charge analysis, I am getting the value of plate distance as 160.84 Angstrom. I am aware that the value of distance is calculated from the capacitance value. But even then why am I getting such a value of capacitance? Attached along with are theinput .py file along with log file (mulliken_analysis.py and mulliken_analysis.log) and the induced charge plot (Device_Graphene_mulliken.png).
2. When I am calculating the value of capacitance using the electrostatic energy analysis, I am getting a plot of Induced density at 1 volt (Device_Graphene_induced.png file) which has two maximas (dips). I wanted to know whether the distance between the dips is same as that of the plate distance d?
1. When the capacitance is being calculated using the induced charge method (Mulliken charge), I am getting a very high value of the plate distance d. When viewed from the structure, the actual value of plate distance d = 10.26 Angstrom whereas from the induced charge analysis, I am getting the value of plate distance as 160.84 Angstrom. I am aware that the value of distance is calculated from the capacitance value. But even then why am I getting such a value of capacitance? Attached along with are theinput .py file along with log file (mulliken_analysis.py and mulliken_analysis.log) and the induced charge plot (Device_Graphene_mulliken.png).
2. When I am calculating the value of capacitance using the electrostatic energy analysis, I am getting a plot of Induced density at 1 volt (Device_Graphene_induced.png file) which has two maximas (dips). I wanted to know whether the distance between the dips is same as that of the plate distance d?
4
General Questions and Answers / Re: Query related to piezoelectric calculation
« on: October 3, 2020, 13:16 »
Ya I have kept large vacuum region along the non periodic direction. However, the calculated coefficient for a 2D material are in the units of C/m^2 whereas the coefficient for a 2D material are in the units of C/m.
5
General Questions and Answers / Re: Query Regarding high symmetry points in band structure calculation
« on: August 31, 2020, 15:27 »
Yes sir you are correct. I have kept a vacuum region in the z-direction however there is a buckling in my structure.
Actually sir, I have communicated a paper by taking default route for band structure. However I have received a comment from the reviewer that "On what basis authors have chosen the high symmetry points to plot phonon and electronic band
structures? As noticed from figure straight lines are observed in г-Z directions. For uniaxial strained band structure (Figure S2), they have used different high symmetry points. There is no clarity. " So can you please suggest me how to defend this?
Thanking you
Actually sir, I have communicated a paper by taking default route for band structure. However I have received a comment from the reviewer that "On what basis authors have chosen the high symmetry points to plot phonon and electronic band
structures? As noticed from figure straight lines are observed in г-Z directions. For uniaxial strained band structure (Figure S2), they have used different high symmetry points. There is no clarity. " So can you please suggest me how to defend this?
Thanking you
6
General Questions and Answers / Query Regarding high symmetry points in band structure calculation
« on: August 31, 2020, 06:11 »
I have plotted the band structure of a tetragonal crystal lattice having space group symmetry p421m using ATK with unit cell dependent route (default route as given by the ATK VNL). In the band structure plot I have seen that the energy values for gamma and Z, R and X are same. In most cases for a tetragonal crystal lattice X, gamma, M and X points are only considered so I want to know, if I do not consider R, X point will it create any problem in band structure? What is the reason behind chosing of these high symmetry points (Z, R) for band structure?
7
General Questions and Answers / Re: 3D band structure plot
« on: August 31, 2020, 05:47 »
Thank you for the reply. I have generated 3D band structure plot as per your suggestion.
8
General Questions and Answers / 3D band structure plot
« on: August 23, 2020, 06:04 »
1. How to generate 3D band structure using QuantumATK? For reference I am attaching one such plot.
2. How to plot atom wise contribution of phonon dos in qunatumATK? I have runned phonon dos and when I am visualizing it using VNL I am getting total phonondos only also I am not getting any setting option to change the plot.
2. How to plot atom wise contribution of phonon dos in qunatumATK? I have runned phonon dos and when I am visualizing it using VNL I am getting total phonondos only also I am not getting any setting option to change the plot.
9
General Questions and Answers / Query Regarding photocurrent in Silicon p-n junction
« on: July 22, 2020, 13:02 »
I am trying to reproduce the photocurrent calculation from tutorial as given on the Quantum ATK website,
https://docs.quantumatk.com/tutorials/photocurrent/photocurrent.html
and in that turorial, while doping the silicon device, it is asked to have the doping of both p and n types in the left electrode only. And i am not able to understand why both the n type and p type dopings are said to be done in the left electrode. So clarify my doubt. attached with this post is a screenshot from the tutorial where the dopings are done.
https://docs.quantumatk.com/tutorials/photocurrent/photocurrent.html
and in that turorial, while doping the silicon device, it is asked to have the doping of both p and n types in the left electrode only. And i am not able to understand why both the n type and p type dopings are said to be done in the left electrode. So clarify my doubt. attached with this post is a screenshot from the tutorial where the dopings are done.
10
General Questions and Answers / Re: Error during phonon transmission calculation
« on: July 17, 2020, 16:05 »
Here I am attaching the script that I have used for the calculation
11
General Questions and Answers / Query related to piezoelectric calculation
« on: July 16, 2020, 06:13 »
I think piezoelectric analysis in quantumATK is implemented for 3D material. Can you please suggest me how to calculate it for a 2D material using quantumATK?
12
General Questions and Answers / Error during phonon transmission calculation
« on: July 15, 2020, 20:35 »
In case of phonon transmission calculation using semiemperical calculator I am facing a problem every time. The calculation is terminated by showing an error pair potential not found. Kindly suggest me how to overcome this.
13
General Questions and Answers / Re: Query Regarding thermoelectric coefficient calculation
« on: June 30, 2020, 10:10 »
I am using the QuantumATK Q-2019.12-SP1 version. As per your suggestion, I am attaching the required files in a single .zip file along with this reply.
14
General Questions and Answers / Query Regarding thermoelectric coefficient calculation
« on: June 25, 2020, 13:30 »
I want to calculate thermoelectric properties of a 2D material by calculating its electron transmission without considering the phononic part. Because for phonon transmission calculation, we have to first design a device configuration and for that very high computational resources are required. Now after calculating the electron transmission calculatuions and viewing the results in the virtual nano lab we are getting various thermoelectric coefficients except ZT which is showing to be Nil. However in the plot, I am obtaining the variation of ZT with respect to energy. So I have doubrt regarding this ZT plot as to where these values are arising from when the value of ZT shown in the nano lab is nil.
15
General Questions and Answers / Query regarding Fermi level shift
« on: June 25, 2020, 11:40 »
In the mobility calculation tutorial, during the calculation of mobility, Fermi shift is set to 0.13 eV and it is mentioned that it corresponds to a carrier concentration of 10^12 cm^-2. Can you please tell how one can obtain the carrier concentration from the Fermi shift.
In many of the published papers, it has been seen that thermoelectric properties have been calculated by varying the carrier concentration. kindly tell how one can incorporate this carrier concentration while calculating thermoelectric properties.
In many of the published papers, it has been seen that thermoelectric properties have been calculated by varying the carrier concentration. kindly tell how one can incorporate this carrier concentration while calculating thermoelectric properties.
Pages: [1]