excitons{ }

Calling sequence

quantum{ region{ excitons{ } } }

Properties

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional}}\)

  • items: maximum 1

Functionality

An optional group triggering computation of binding energies of excitons.

Note

This feature is under development.

Attention

This model can be used only for 1D simulations.

Nested keywords

electron_mass

Calling sequence

quantum{ region{ excitons{ electron_mass = ... } } }

Properties

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional}}\)

  • type: real number

  • values: \(10^{-3} \leq r \leq 10.0\)

  • default: volume average of values from the material database

  • unit: \(\mathrm{-}\)

Functionality

Effective mass of electron involved in the exciton.

hole_mass

Calling sequence

quantum{ region{ excitons{ hole_mass = ... } } }

Properties

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional}}\)

  • type: real number

  • values: \(10^{-3} \leq r \leq 10.0\)

  • default: volume average of values from the material database

  • unit: \(\mathrm{-}\)

Functionality

Effective mass of hole involved in the exciton.

density_averaged_masses

Calling sequence

quantum{ region{ excitons{ density_averaged_masses = ... } } }

Properties

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional}}\)

  • type: choice

  • values: yes or no

  • default: no

Functionality

Effective masses of hole and electron are averaged with weights taken from probability densities of related states

dielectric_const

Calling sequence

quantum{ region{ excitons{ dielectric_const = ... } } }

Properties

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional}}\)

  • type: real number

  • values: \(1.0 \leq r \leq 10^{3}\)

  • default: volume average of values from the material database

  • unit: \(\mathrm{-}\)

Functionality

Effective dielectric constant assumed for electron-hole Coulomb interaction; If no explicit value of the dielectric constant is set, then the material values of the static dielectric constant (as given by the database and used in Poisson equation) are volume-averaged over the quantum region

energy_cutoff

Calling sequence

quantum{ region{ excitons{ energy_cutoff = ... } } }

Properties

  • usage: \(\mathrm{\textcolor{WildStrawberry}{required}}\)

  • type: real number

  • values: [1e-3, ...)

  • unit: \(\mathrm{eV}\)

Functionality

Maximum energy difference of electron and hole states involved in forming exciton

accuracy

Calling sequence

quantum{ region{ excitons{ accuracy = ... } } }

Properties

  • usage: \(\mathrm{\textcolor{ForestGreen}{optional}}\)

  • type: real number

  • values: \(10^{-10} \leq r \leq 0.1\)

  • default: \(r=1e-4\)

  • unit: \(\mathrm{-}\)

Functionality

Accuracy used in minimisation procedure to compute the exciton binding energy

Last update: 27/05/2025