Numerical analysis of steady-state and transient charge transport in organic semiconductor devices

A one-dimensional numerical model for the simulation of organic light-emitting devices (OLEDs) is presented. The model accounts for the disordered nature of organic semiconductors by a Gaussian density of states and the use of the Fermi-Dirac statistics. It includes density- and field-dependent mobilities and the generalized Einstein relation. The novel model ingredients perform well in combination with the numerical methods which solve the drift-diffusion problem. The results of three different measurement setups are reproduced by the use of different numerical techniques, i.e. we efficiently simulate current-voltage curves, dark-injection transients and impedance spectroscopy. This is crucial for model validation and parameter extraction. We compare the simulations with analytical solutions and measurements.