OLED device structures
Devices having multiple multicomponent emissive layers are provided, where each multicomponent EML includes at least three components. Each of the components in each EML is a host material or an emitter. The devices have improved color stability and relatively high luminance.
1. A device comprising:
a first emissive layer disposed between a first electrode and a second electrode, the first emissive layer comprising:
a first host material,
a second host material different than the first host material, wherein the highest occupied molecular orbital (HOMO) of the first host material is within 0.8 eV of the HOMO of the second host material, and
at least one component selected from the group consisting of:
a first emissive material, and
a second emissive material different than the first emissive material; and
a second emissive layer disposed between the first electrode and the second electrode and in direct physical contact with the first emissive layer, the second emissive layer comprising at least three components, each individually and uniquely selected from the group consisting of:
a third host material,
a fourth host material different than the third host material,
a third emissive material, and
a fourth emissive material different than the third emissive material.
2. The device of claim 1 , wherein the first emissive layer has a thickness of not more than 30% of the thickness of the second emissive layer.
3. The device of claim 1 , wherein the LUMO of the first host material is within 0.8 eV of the LUMO of the second host material.
4. The device of claim 1 , wherein:
the first emissive layer comprises:
the first emissive material; and
the second emissive layer comprises:
the third host material;
the fourth host material, wherein the fourth host material is different than the third host material; and
the second emissive material;
wherein the third host material is different than the first host material.
5. The device of claim 4 , wherein the fourth host material is different than the second host material.
6. The device of claim 4 , wherein the second emissive layer comprises:
the third host material, wherein the third host material comprises the first host material;
the fourth host material, wherein the fourth host material comprises the second host material; and
the second emissive material;
wherein the relative concentration of host materials is different in the first emissive layer than in the second emissive layer.
7. The device of claim 4 , wherein the third organic emissive material comprises the first emissive material.
8. The device of claim 1 , wherein:
the first emissive layer comprises:
the first emissive material; and
the second emissive material, wherein the second emissive material is different than the first emissive material; and
the second emissive layer comprises:
the third host material;
the third emissive material; and
the fourth emissive material, wherein the fourth emissive material is different than the third emissive material;
wherein the third emissive material is different than the first emissive material.
9. The device of claim 8 , wherein the fourth emissive material is different than the second emissive material.
10. The device of claim 8 , wherein the third host material comprises the first host material.
11. The device of claim 1 , wherein:
the first emissive layer comprises:
a red organic emissive material; and
the second emissive layer comprises:
the third host material, wherein the third host material comprises the first host material;
the fourth host material; and
a green organic or organometallic emissive material; and
wherein the first emissive layer has a thickness of not more than 30% of the second emissive layer.
12. The device of claim 1 , further comprising a third emissive layer, the third emissive layer comprising at least three components, each independently selected from the group consisting of: a fifth host material, a sixth host material, a fifth emissive material, and a sixth emissive material.
13. The device of claim 12 , wherein the fifth host material comprises the first host material, and the sixth host material comprises the second host material.
14. The device of claim 1 , wherein the first emissive layer comprises the first host material and the second host material in a ratio in the range of 5-95%.
15. The device of claim 14 , wherein the first emissive layer comprises the first host material and the second host material in a ratio in the range of 5-50%.
16. The device of claim 1 , wherein the first emissive layer comprises the first host material and the second host material in a ratio in the range of 30-40%.
17. The device of claim 1 , wherein the first emissive layer comprises the first emissive material and the second emissive material in a ratio in the range of 1-25%.
18. The device of claim 1 , wherein the first emissive layer comprises the first emissive material and the second emissive material in a ratio in the range of 0.1-10%.
19. The device of claim 1 , wherein the first emissive layer comprises the first emissive material and the second emissive layer comprises the third emissive material, wherein the ratio of the first emissive material to the third emissive material is in in the range of 5 to 30%.
20. A device comprising:
a first emissive layer disposed between a first electrode and a second electrode, the first emissive layer comprising:
a first host material,
a second host material different than the first host material, wherein the lowest unoccupied molecular orbital (LUMO) of the first host material is within 0.8 eV of the LUMO of the second host material, and
at least one component selected from the group consisting of:
a first emissive material, and
a second emissive material different than the first emissive material; and
a second emissive layer disposed between the first electrode and the second electrode and in direct physical contact with the first emissive layer, the second emissive layer comprising at least three components, each individually and uniquely selected from the group consisting of:
a third host material,
a fourth host material different than the third host material,
a third emissive material, and
a fourth emissive material different than the third emissive material.
21. The device of claim 20 , wherein the first emissive layer has a thickness of not more than 30% of the thickness of the second emissive layer.
22. The device of claim 20 , wherein:
the first emissive layer comprises the first emissive material; and
the second emissive layer comprises:
the third host material;
the fourth host material, wherein the fourth host material is different than the third host material; and
the second emissive material;
wherein the third host material is different than the first host material.
23. The device of claim 22 , wherein the fourth host material is different than the second host material.
24. The device of claim 22 , wherein the second emissive layer comprises:
the third host material, wherein the third host material comprises the first host material;
the fourth host material, wherein the fourth host material comprises the second host material; and
the second emissive material;
wherein the relative concentration of host materials is different in the first emissive layer than in the second emissive layer.
25. The device of claim 22 , wherein the third organic emissive material comprises the first emissive material.
26. The device of claim 20 , wherein:
the first emissive layer comprises:
the first emissive material; and
the second emissive material, wherein the second emissive material is different than the first emissive material; and
the second emissive layer comprises:
the third host material;
the third emissive material; and
the fourth emissive material, wherein the fourth emissive material is different than the third emissive material;
wherein the third emissive material is different than the first emissive material.
27. The device of claim 26 , wherein the fourth emissive material is different than the second emissive material.
28. The device of claim 26 , wherein the third host material comprises the first host material.
29. The device of claim 20 , wherein:
the first emissive layer comprises a red organic emissive material; and
the second emissive layer comprises:
the third host material, wherein the third host material comprises the first host material;
the fourth host material; and
a green organic or organometallic emissive material; and
wherein the first emissive layer has a thickness of not more than 30% of the second emissive layer.
30. The device of claim 20 , further comprising a third emissive layer, the third emissive layer comprising at least three components, each independently selected from the group consisting of: a fifth host material, a sixth host material, a fifth emissive material, and a sixth emissive material.
31. The device of claim 30 , wherein the fifth host material comprises the first host material, and the sixth host material comprises the second host material.
32. The device of claim 20 , wherein the first emissive layer comprises the first host material and the second host material in a ratio in the range of 5-95%.
33. The device of claim 32 , wherein the first emissive layer comprises the first host material and the second host material in a ratio in the range of 5-50%.
34. The device of claim 32 , wherein the first emissive layer comprises the first host material and the second host material in a ratio in the range of 30-40%.
35. The device of claim 20 , wherein the first emissive layer comprises the first emissive material and the second emissive material in a ratio in the range of 1-25%.
36. The device of claim 20 , wherein the first emissive layer comprises the first emissive material and the second emissive material in a ratio in the range of 0.1-10%.
37. The device of claim 20 , wherein the first emissive layer comprises the first emissive material and the second emissive layer comprises the third emissive material, wherein the ratio of the first emissive material to the third emissive material is in in the range of 5 to 30%.