FreeCarrier2D Class

class gain.freecarrier.FreeCarrier2D(name='')

Quantum-well gain using free-carrier approximation for two-dimensional Cartesian geometry.

Subclasses

Spectrum

Gain spectrum object.

Methods

get_energy_levels([T])	Get energy levels in quantum wells.
get_fermi_levels(n[, T, reg])	Get quasi Fermi levels.
initialize()	Initialize solver.
invalidate()	Set the solver back to uninitialized state.
spectrum(...)	Get gain spectrum at given point.

Attributes

Receivers

inBandEdges	Receiver of the conduction and valence band edges required for computations [eV].
inCarriersConcentration	Receiver of the carriers concentration required for computations [1/cm³].
inFermiLevels	Receiver of the quasi-Fermi levels for electrons and holes required for computations [eV].
inTemperature	Receiver of the temperature required for computations [K].

Providers

outEnergyLevels	Provider of the computed energy levels for electrons and holes [eV].
outGain	Provider of the computed material gain [1/cm].

Other

T0	Reference temperature.
geometry	Geometry provided to the solver
id	Id of the solver object.
initialized	True if the solver has been initialized.
lifetime	Average carriers lifetime.
matrix_element	Momentum matrix element.
mesh	Mesh provided to the solver
strained	Boolean attribute indicating if the solver should consider strain in the active region.
substrate	Substrate material.

Descriptions

Method Details

FreeCarrier2D.get_energy_levels(T=None)

Get energy levels in quantum wells.

Compute energy levels in quantum wells for electrons, heavy holes and light holes.

Parameters:

T (float or None) – Temperature to get the levels. If this argument is None, the estimates for temperature T0 are returned.

Returns:

List with dictionaries with keys el, hh, and lh with levels for

electrons, heavy holes and light holes. Each list element corresponds to one active region.

Return type:

list

FreeCarrier2D.get_fermi_levels(n, T=None, reg=0)

Get quasi Fermi levels.

Compute quasi-Fermi levels in specified active region.

Parameters:

• n (float) – Carriers concentration to determine the levels for (1/cm³).

• T (float or None) – Temperature to get the levels. If this argument is None, the estimates for temperature T0 are returned.

• reg (int) – Active region number.

Returns:

Two-element tuple with quasi-Fermi levels for electrons and holes.

Return type:

tuple

FreeCarrier2D.initialize()

Initialize solver.

This method manually initialized the solver and sets initialized to True. Normally calling it is not necessary, as each solver automatically initializes itself when needed.

Returns:

solver initialized state prior to this method call.

Return type:

bool

FreeCarrier2D.invalidate()

Set the solver back to uninitialized state.

This method frees the memory allocated by the solver and sets initialized to False.

FreeCarrier2D.spectrum(c0, c1)

FreeCarrier2D.spectrum(point)

Get gain spectrum at given point.

Parameters:

• point (vec) – Point to get gain at.

• c0 (float) – Coordinates of the point to get gain at.

• c1 (float) – Coordinates of the point to get gain at.

Returns:

Spectrum object.

Return type:

FreeCarrier2D.Spectrum

Receiver Details

FreeCarrier2D.inBandEdges = <property object>

Receiver of the conduction and valence band edges required for computations [eV].

You will find usage details in the documentation of the receiver class BandEdgesReceiver2D.

Example

Connect the receiver to a provider from some other solver:

>>> solver.inBandEdges = other_solver.outBandEdges

See also

Receciver class: plask.flow.BandEdgesReceiver2D

Provider class: plask.flow.BandEdgesProvider2D

Data filter: plask.filter.BandEdgesFilter2D

FreeCarrier2D.inCarriersConcentration = <property object>

Receiver of the carriers concentration required for computations [1/cm³].

You will find usage details in the documentation of the receiver class CarriersConcentrationReceiver2D.

Example

Connect the receiver to a provider from some other solver:

>>> solver.inCarriersConcentration = other_solver.outCarriersConcentration

See also

Receciver class: plask.flow.CarriersConcentrationReceiver2D

Provider class: plask.flow.CarriersConcentrationProvider2D

Data filter: plask.filter.CarriersConcentrationFilter2D

FreeCarrier2D.inFermiLevels = <property object>

Receiver of the quasi-Fermi levels for electrons and holes required for computations [eV].

You will find usage details in the documentation of the receiver class FermiLevelsReceiver2D.

Example

Connect the receiver to a provider from some other solver:

>>> solver.inFermiLevels = other_solver.outFermiLevels

See also

Receciver class: plask.flow.FermiLevelsReceiver2D

Provider class: plask.flow.FermiLevelsProvider2D

Data filter: plask.filter.FermiLevelsFilter2D

FreeCarrier2D.inTemperature = <property object>

Receiver of the temperature required for computations [K].

You will find usage details in the documentation of the receiver class TemperatureReceiver2D.

Example

Connect the receiver to a provider from some other solver:

>>> solver.inTemperature = other_solver.outTemperature

See also

Receciver class: plask.flow.TemperatureReceiver2D

Provider class: plask.flow.TemperatureProvider2D

Data filter: plask.filter.TemperatureFilter2D

Provider Details

FreeCarrier2D.outEnergyLevels(n=0, mesh, interpolation='default') = <property object>

Provider of the computed energy levels for electrons and holes [eV].

Parameters:

• n (int) – Value number.

• mesh (mesh) – Target mesh to get the field at.

• interpolation (str) – Requested interpolation method.

Returns:

Data with the energy levels for electrons and holes on the specified mesh [eV].

You may obtain the number of different values this provider can return by testing its length.

Example

Connect the provider to a receiver in some other solver:

>>> other_solver.inEnergyLevels = solver.outEnergyLevels

Obtain the provided field:

>>> solver.outEnergyLevels(0, mesh)
<plask.Data at 0x1234567>

Test the number of provided values:

>>> len(solver.outEnergyLevels)
3

See also

Provider class: plask.flow.EnergyLevelsProvider2D

Receciver class: plask.flow.EnergyLevelsReceiver2D

FreeCarrier2D.outGain(n=0, mesh, lam, interpolation='default') = <property object>

Provider of the computed material gain [1/cm].

Parameters:

• deriv (str) – Gain derivative to return. can be ‘’ (empty) or ‘conc’. In the latter case, the gain derivative over carriers concentration is returned.

• mesh (mesh) – Target mesh to get the field at.

• interpolation (str) – Requested interpolation method.

• lam (float) – The wavelength at which the gain is computed (nm).

Returns:

Data with the material gain on the specified mesh [1/cm].

You may obtain the number of different values this provider can return by testing its length.

Example

Connect the provider to a receiver in some other solver:

>>> other_solver.inGain = solver.outGain

Obtain the provided field:

>>> solver.outGain(0, mesh, lam)
<plask.Data at 0x1234567>

Test the number of provided values:

>>> len(solver.outGain)
3

See also

Provider class: plask.flow.GainProvider2D

Receciver class: plask.flow.GainReceiver2D

Attribute Details

FreeCarrier2D.T0 = <property object>

Reference temperature.

In this temperature levels estimates are computed.

FreeCarrier2D.geometry = <property object>

Geometry provided to the solver

FreeCarrier2D.id = <property object>

Id of the solver object. (read only)

Example

>>> mysolver.id
mysolver:category.type

FreeCarrier2D.initialized = <property object>

True if the solver has been initialized. (read only)

Solvers usually get initialized at the beginning of the computations. You can clean the initialization state and free the memory by calling the invalidate() method.

FreeCarrier2D.lifetime = <property object>

Average carriers lifetime.

This parameter is used for gain spectrum broadening. (float [ps])

FreeCarrier2D.matrix_element = <property object>

Momentum matrix element.

Value of the squared matrix element in gain computations. If it is not set it is estimated automatically. (float [eV×m0])

FreeCarrier2D.mesh = <property object>

Mesh provided to the solver

FreeCarrier2D.strained = <property object>

Boolean attribute indicating if the solver should consider strain in the active region.

If set to True then there must a layer with the role substrate in the geometry. The strain is computed by comparing the atomic lattice constants of the substrate and the quantum wells.

FreeCarrier2D.substrate = <property object>

Substrate material.

Material of the substrate. This is used to compute strain in the active region. If not set, the solver looks for geometry object with the __substrate__ role.