This is a theory containing the stationary van Roosbroeck system
describung the charge transport of electrons and holes
in a one-dimensional (layered) semiconductor device.
The model includes electron and hole
densities according the Boltzmann approximation and
spontaneous radiative recombination processes only.
Furthermore the material properties such as band edges,
density of states, mobilties are assumed to be
homogenous (spatially constant). Also a homogenous device
temperature is assumed.
http://mathhub.info/MitM/Models/VanRoosbroeck?VanRoosbroeck