Long lifetime phosphorescent organic light emitting device (OLED) structures

摘要

An organic light emitting device is provided having an emissive layer with an internal interface. The concentration of a second phosphorescent material in a second organic layer is different from the concentration of a first phosphorescent material in a first organic layer, creating the interface. The materials in the first and second organic layers may be the same or different. In addition to this interface within the emissive layer, the device has one or more features designed to mitigate failure mechanisms which may be associated with electrons or excitons passing from the cathode through the emissive layer to damage organic layers on the anode side of the emissive layer. In addition, devices are provided having an interface within the emissive layer as described above, and a lower energy emissive material on at least one side of the interface.

主权项

1. An organic light emitting device, comprising:
an anode; a cathode; an emissive layer disposed between the anode and the cathode, the emissive layer further comprising:
a first organic layer comprising a first phosphorescent material and a first nonemissive material, wherein
the concentration of the first phosphorescent material in the first organic layer is 10-90 wt %; andthe concentration of the first non-emissive material in the first organic layer is 10-90 wt %;a second organic layer comprising a second phosphorescent material anda second non-emissive material, wherein
the concentration of the second phosphorescent material in the second layer is 3-25 wt %; andthe concentration of the second non-emissive material in the second organic layer is 75-97 wt %;wherein the concentration of the second phosphorescent material in the second organic layer is lower than the concentration of the first phosphorescent material in the first organic layer;wherein the first non-emissive material and the second non-emissive material may be the same material or different materials, and the first phosphorescent material and the second phosphorescent material may be the same material or different materials;wherein all organic layers between the first organic layer and the anode do not include any materials containing a group selected from the group consisting of triarylamine, napthyl, tri(N-carbazoyl)triphenylamine, tetraarylamine and carbazole;a third organic layer disposed between the first organic layer and the anode; andwherein the first phosphorescent material and the second phosphorescent material are the same material, and the first non-emissive material and the second non-emissive material are the same material.