Author Topic: Simulated current-voltage characteristics and extraction of n  (Read 4878 times)

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Offline 395235863

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Dear QuantumWise Staff,

  where can i get the orgin of the pic.Thank you!

Offline Daniele Stradi

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Re: Simulated current-voltage characteristics and extraction of n
« Reply #1 on: February 29, 2016, 09:43 »
Please refer to this article for the relevant methods and references:
http://arxiv.org/abs/1601.04651

Offline 395235863

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How to calculate the I-V of Device with different temperature in ATK?
Thank you!

Offline zh

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The temperature of lattice atoms in the device couldn't be taken into account. You can consider the electron temperature by means of the temperature parameters in Fermi distribution.

Offline 395235863

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How to plot this pic (1.jpg)in the article (http://arxiv.org/abs/1601.04651) by ATK?

The interface's current in different temperature?

Thank you very much!

Offline Anders Blom

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See http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.transmissionspectrum.html
In the method current()  you provide the electrode temperatures in order to simulate the current at different electron temperature.
Just don't confuse this with lattice temperature.

Offline 395235863

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How to plot the pic 2 and the BLUE line calculated by ATK?
Thank you very much!

Offline Daniele Stradi

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The density of states can be obtained using the ProjectedLocalDensityOfStates object:
http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.projectedlocaldensityofstates.html

The blue line is the system electrostatic difference potential:
http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.electrostaticdifferencepotential.html

Notice that, to match the conduction band minimum of the semiconductor, the electrostatic difference potential has been shifted by (i) subtracting the chemical potential of the right silicon electrode, that is the silicon electrode and (ii) adding the difference in energy between the conduction band minimum of doped bulk silicon and the Fermi energy.

Offline 395235863

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I used a model (pic3)and get the LDOS(pic4).
Then how to plot the blue line like the one mentioned above?
Thank you very much!

Offline Jess Wellendorff

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Use the axisProjection method mentioned in the EDF entry in the reference manual (link provided above by Daniele) to project the EDF onto the C-axis and perform the shifts that Daniele described.

Offline 395235863

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1.
I have created a new model like metal-semiconductor(different metal and semiconductor) interface in paper(http://arxiv.org/abs/1601.04651)
In my log file,
left   electrode  Fermi level = -2.820920 eV,
right electrode  Fermi level = -3.757656 eV,
Equivalent Bulk Fermi level = -3.499385 eV,
Left   electrode chemical potential = -2.820920 eV 
Right electrode chemical potential = -2.820920 eV
Left   electrode Fermi level  = -2.820920 eV   
Right electrode Fermi level = -2.820920 eV       
Energy zero  = -2.820920 eV 
2.
I also calculated the bandstructure of the semiconductor(MoS2) 
the difference in energy between the conduction band minimum of semiconductor and the Fermi energy=
CBM0=CBM-Ef=0.842 eV
3.
EDF-(i)+(ii)=EDF-the chemical potential of the right electrode(-2.820920 eV)+CBM0(0.842eV)=EDF+2.820920+0.842
4. are all right ?
Thank you very much!

Offline 395235863

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Re: Simulated current-voltage characteristics and extraction of n
« Reply #11 on: March 12, 2016, 05:35 »
1.In my device calculation(left electrode=Au-monolayer MoS2 topcontact;right electrode=monolayer MoS2)[PBE-GGA-DFTD2]
In my log file,
left   electrode  Fermi level = -2.820920 eV,
right electrode  Fermi level = -3.757656 eV,
Equivalent Bulk Fermi level = -3.499385 eV,
Left   electrode chemical potential = -2.820920 eV 
Right electrode chemical potential = -2.820920 eV

Transmission Spectrum Report
Left   electrode Fermi level  = -2.820920 eV   
Right electrode Fermi level = -2.820920 eV       
Energy zero  = -2.820920 eV 

2.Then i split my device into 3 regions.To calculate two electrodes as bulk.

right electrode bulk(monolayer MoS2)[PBE-GGA]
Fermi level = -4.010094e+00 
Unit = eV

left electrode bulk(Au-monolayer MoS2 topcontact)[PBE-GGA-DFTD2]
Fermi level = -2.763682e+00
Unit = eV

3.My question is what makes the difference(3.757656 4.010094)(2.820920 2.763682)
and when i shift the electrostatic difference potential,what value should i use?

Thanks for your time !

Offline Daniele Stradi

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Re: Simulated current-voltage characteristics and extraction of n
« Reply #12 on: March 21, 2016, 10:27 »
You should use the "Left   electrode chemical potential" from the device calculation: -2.820920 eV