ORGANIC LIGHT EMITTING DEVICE WITH INCREASED LIGHT OUT COUPLING

The invention relates to an organic light-emitting device (OLED) comprising at least: a first electrode; a second electrode; an organic light emissive layer arranged between said first electrode and said second electrode; and an organic charge transport layer arranged between said first electrode and said emissive layer, wherein i) the charge transport layer is patterned or provided with a periodic surface structure on a surface of the charge transport layer facing the emissive layer, and/or ii) an alignment layer which allows for charge transport to the emissive layer is provided between said charge transport layer and said emissive layer, which alignment layer promotes alignment of the optical dipoles of molecules of said light emissive layer towards a common preferred direction of the molecular axes. The use of the patterned or structured charge transport layer and/or the alignment layer provides improved light out coupling from the OLED layer stack, i.e. increased external quantum efficiency.