Color stable multicolor OLED device structures
AssigneeUniversal Display Corporation
InventorsVadim Adamovich, Michael Stuart Weaver
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Abstract
The present invention relates to OLED devices and stacks for OLED devices that include a symmetric emissive-layer architecture. In one embodiment, the present invention relates to an emissive stack having three layers, wherein the top and bottom layers emit light in the same or similar color region while the middle layer emits light in a different color region than the other two layers. In such an embodiment, the three layers are in contact with each other with no other layers in between. The symmetric emissive-layer architecture of the present invention can be used to improve the color stability of OLED devices.
Claims20
An organic light emitting device, comprising:
- a first electrode;
- a hole transport layer disposed over the first electrode;
- an emissive stack disposed over the first electrode, the emissive stack comprising:
- a first emissive layer comprising a first host material having a lowest unoccupied molecular orbital (LUMO) LUMO(H1) and a first emissive material having a LUMO energy level LUMO(D1) that emits a first color;
- a second emissive layer in direct physical contact with the first emissive layer, the second emissive layer comprising a second host material having a LUMO energy level LUMO(H2) and a second emissive material having a LUMO energy level LUMO(D2) that emits a second color, wherein the second color is different than the first color;
- and
- a third emissive layer in direct physical contact with the second emissive layer and comprising a third host material having a LUMO energy level LUMO(H3) and a third emissive material, different than the first emissive material, having a LUMO energy level LUMO(D3) that emits the first color;
- an electron transport layer disposed over the emissive stack;
- and
- a second electrode disposed over the emissive stack;
- wherein:
- LUMO(H1)<LUMO(D1);
- and
- LUMO(H2)−LUMO(D2)<LUMO(H1)−LUMO(D1).
Dependencies are inferred from the claim text.