The position of an emitter with respect to the grating has a large influence on the radiation pattern. A 5 nm mesh resolution is determined as a good compromise between accuracy and simulation time. The necessary simulation domain size is derived by considering propagation length and field profile of the guided mode of a corresponding unstructured OLED. Radiation patterns of single dipole emitters placed in a sufficiently large simulation domain are superimposed to model the incoherent emission of a continuous emission layer. We present a theoretical study investigating simulation conditions for accurate radiation patterns employing the FDTD method.
Nanostructures in OLEDs allow to manipulate the radiation pattern and direct light of a specific wavelength into a specific angle in the far field by resonant light outcoupling.