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.


Messages - skg

Pages: [1] 2
1
Thanks for the quick reply.
In the given tutorial we are calculating the mobility using Boltzmann transport equation, using RTA approximation, which is independent of effective mass. My confusion is whether the relaxation time (scattering time) is independent of LDA or GGA.

2
General Questions and Answers / Mobility calculation in ATK
« on: July 11, 2016, 11:56 »
Dear sir,
I am trying to calculate the mobility for Silicon, following the tutorial given in link:
http://docs.quantumwise.com/tutorials/mobility.html#id11

For silicon electronic band structure calculation, I am applying MGGA (since LDA or GGA underestimates the band gap) , but ATK is not allowing me to calculate the dynamical matrix elements using MGGA. Throwing an error message "Back Engine Exception : MGGACalculator does not implement this method."

Can you please tell me how to proceed on that and calculate the mobility for silicon.


3
Hi,
  Thanks for quick reply. As you asked earlier about the BZ, when we cleave along [1 0 0], we get a square shaped BZ. The coordinates of L points in reciprocal vectors is (0.5, 0.5, 0.5) as given in ATK for the same BZ. We also plotted band structure along G- C , the co-ordinate of C being (0.5, 0.5, 0.0), which seems more logical in a 2D slab system and it wasn't much different from what we got along G-L. We are also attaching the BZ for clarification. I just want to know that are we doing correctly or is there anything wrong with the method, in which case please tell us the correct way to do so.
 

4
So, do you mean different nomenclature than others?

The example (http://quantumwise.com/documents/tutorials/latest/InAs-2D/index.html/chap.slab.html) is for 8 layers (and not 1 layer), and we found that the relative positions of “L” and “X” valleys don't change on changing the number of layers from 4 to 40 layers.

So  my question remains the same.
Here are some snapshots to further clarify the question (Note the X valley in ATK is called L valley in existing literature)

Image1 : Bandstructure of 2.43 nm thick slab (8 layers)
Image2: Bandstructure of 3 and 5 nm thick InAs slab. Taken from[2]

5
General Questions and Answers / bandstructure of InAs slab
« on: June 3, 2015, 15:37 »
Hi,
We calculated the bandstructure of InAs slab (same as the example given on ATK tutorial). We found that the X valley is lower than the L valley, while in the bulk, it's the reverse. Existing literature (e.g. 2.6nm thick slab[1], 3nm and 5nm thick slab[2]), report using TB calculations, that the L valley is lower than the X valley, similar to the bulk case. Could you please explain this difference? Is it due to a different nomenclature used by ATK?

Best Regards,


[1] Y. Liu et al., “Band-structure effects on the performance of III-V ultrathin-body SOI MOSFETs,” IEEE Trans. Electron Devices, vol. 55, no. 5, pp. 1116–1122, 2008.
[2] Mugny, G., et al. "Band structure of III-V thin films: An atomistic study of non-parabolic effects in confinement direction,"  Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon ((EUROSOI-ULIS) 2015.

6
General Questions and Answers / dielectric constant of bulk
« on: March 23, 2015, 22:07 »
Dear Sir,
could you please tell me how to calculate dielectric constant of any bulk material.

Thanks

7
General Questions and Answers / Re: Regarding Polarization
« on: February 16, 2015, 06:32 »
Dear Sir,
Thanks for replying our query. We are attaching  script and output for your reference. Please respond at your convenience.
Thanks.

8
General Questions and Answers / Regarding Polarization
« on: February 15, 2015, 10:55 »
Dear Sir,
We have tried to reproduce the polarization results for BaTiO3, but not succeed. Please comment!
Thanks

Moderator edit: Fixed typo in subject

9
General Questions and Answers / blue phosphorene
« on: January 6, 2015, 10:57 »
Dear Sir,
 I have reproduced the band structure of blue phosphorene given in http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.176802 our  result is almost same However, I am trying to reproduced another paper http://arxiv.org/abs/1412.0858 in which effect of vertical electric field is shown on monolayer blue phosphorene as well as bilayer phosphorene; but i am not getting effect of vertical electric field  on monolayer. Could you please tell me whether my structure is right or not? What in your opinion might be the possible reason for the  the problem mentioned above?

10
General Questions and Answers / Re: Res2 structure
« on: January 5, 2015, 08:10 »
please reply.......

11
General Questions and Answers / Res2 structure
« on: January 2, 2015, 13:15 »
HI,
 I am trying to make ReS2 structure through  crystal builder. Could you please explain how to make ReS2 structure.

12
General Questions and Answers / blue phosphorene
« on: December 23, 2014, 14:27 »
Dear Sir,
 I have reproduced the band structure of blue phosphorene given in http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.176802 our  result is almost same However, I am trying to reproduced another paper http://arxiv.org/abs/1412.0858 in which effect of vertical electric field is shown on monolayer blue phosphorene as well as bilayer phosphorene; but i am not getting effect of vertical electric field  on monolayer. Could you please tell me whether my structure is right or not? What in your opinion might be the possible reason for the  the problem mentioned above?

13
General Questions and Answers / Max interaction range
« on: December 6, 2014, 15:12 »
Dear Sir,
Could you please tell me how to fix the value of maximum interaction range.





thanks

14
General Questions and Answers / PDOS through pylab
« on: June 14, 2014, 22:08 »
Hi,
please explain how we get PDOS spectrum through pylab.






Thanks
skg

15
Hi,
please explain. can we calculate charge transfer from material to adsorbed atom in atk.




thanks

Pages: [1] 2