QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: tara on March 4, 2015, 08:00

Title: doping script
Post by: tara on March 4, 2015, 08:00

1.In the p-n junction tutorial ,
the doping for n region is taken as ,doping and  for p-region it is  -1*doping. why is it opposite?

2.Secondly the length of only right electrode is considered for both p and n regions.  [  len(right_electrode_elements) ]. Has it been assumed that right and left electrodes are identicle and symetric??

3.  The doping script should come before or after
device_configuration = DeviceConfiguration(
    central_region,
    [left_electrode, right_electrode]
    )    ????
                                                                       

# -------------------------------------------------------------
# Add Doping
# -------------------------------------------------------------
doping_density = 2e+19
# Calculate the volume  and convert it to cm^-3
# Note: right and left electrodes have the same volume,
volume = right_electrode_lattice.unitCellVolume()
volume = float(volume/(0.01*Meter)**3)
# Calculate charge per atom
doping = doping_density * volume / len(right_electrode_elements)
# Add p- and n-type doping to the central region
external_potential = AtomicCompensationCharge([
        ('p_doping', -1*doping), ('n_doping',doping)
        ])
central_region.setExternalPotential(external_potential)
# Add doping to left and right electrodes
left_electrode.setExternalPotential(
      AtomicCompensationCharge([(Silicon, -1*doping)]))
right_electrode.setExternalPotential(
      AtomicCompensationCharge([(Silicon, doping)]))

Title: Re: doping script
Post by: tara on March 4, 2015, 08:11

Also when i tried  doping  mos2 using

left_electrode.setExternalPotential(
      AtomicCompensationCharge([(Molybdenite, -1*doping)]))
right_electrode.setExternalPotential(
      AtomicCompensationCharge([(Molybdenite, doping)]))

NameError: name 'Molybdenite' is not defined
 what name should we use for doping entire mos2??

Title: Re: doping script
Post by: Anders Blom on March 4, 2015, 09:32

What chemical element is Molybdenite? I think you mean Molybdenum.

Title: Re: doping script
Post by: Umberto Martinez on March 4, 2015, 09:51

1 - This is explained in more details in the Doping in ATK: the Ni silicide - Si interfaces (http://quantumwise.com/publications/tutorials/item/820-ni-silicide-si-interfaces) tutorial.
negative values correspond to p-dpoing and positive value to n-doping (adding charge).
see also http://www.quantumwise.com/documents/manuals/latest/ReferenceManual/index.html/ref.atomiccompensationcharge.html

2 - yes, in this case the two electrodes have the same size. Please adapt the script to your system.

3- after.