Optical design for efficient light emission in OLEDs and anisotropic layers

摘要

The light emission from an electrical dipole antenna is determined by the orientation of the antenna and the optical properties of the materials that surround it. For the outcoupling efficiency of an OLED it is beneficial if the dipole moment of the luminescent transition is parallel with the substrate. In some OLEDs a preferential orientation of the emitting molecules can indeed be observed. In this paper we discuss how anisotropy of the dipole orientation and optical anisotropy of the materials influence the light emitted from a planar structure. Numerical simulations are verified with measurements of OLEDs (for the dipole orientation) and dye doped liquid crystals (for the optical anisotropy).