Organic light emitting device having a microcavity

• US 7,800,295 B2
• Filed: 09/15/2006
• Issued: 09/21/2010
• Est. Priority Date: 09/15/2006
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Weaver, Mike, D'Andrade, Brian
• Primary Examiner(s): Roy; Sikha
• Assistant Examiner(s): GREEN, TRACIE Y
• Application Number:
  US11/521,431
• Publication Number:
  US 20080067921A1
• Time in Patent Office: 1,467 Days
• Field of Search: 313500-512
• US Class Current: 313/504
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths

Abstract

The present invention provides OLEDs incorporating microcavities. By combining a microcavity with a non-microcavity emissive layer, improved saturation and luminance may be achieved. OLEDs incorporating microcavities according to the invention may be used to produce white light, and as sub-pixels in full-color displays.

Claims

1. A device comprising:

a first electrode;

a second electrode;

a third electrode;

a first organic emissive layer disposed between the first electrode and the second electrode; and

a second organic emissive layer disposed between the second electrode and the third electrode;

wherein;

the first electrode and the second electrode define a microcavity, said microcavity shifting the CIE coordinates of the emission of the first organic emissive layer such that the device emits light having a CIE of (0.33±

0.05, 0.33±

0.05);

there are no electrodes between the first electrode and the second electrode;

the second electrode and the third electrode define a standard OLED;

the first organic emissive layer comprising a single first emissive material that emits in a first wavelength region, and the second organic emissive layer comprising a single second emissive material that emits in a second wavelength region, the first wavelength region being shorter than the second wavelength region; and

the combination of the unshifted emission spectrum of the first emissive layer and the emission spectrum of the second emissive layers does not result in emitted light having a CIE of (0.33±

0.05, 0.33±

0.05).

2. The device of claim 1 wherein the device has an operational half-life of at least 25,000 hours at 500 cd/m².

3. The device of claim 1 wherein the device has an operational half-life of at least 40,000 hours at 500 cd/m².

4. The device of claim 1 wherein the device has an operational half-life of at least 25,000 hours at 1500 cd/m².

5. The device of claim 1 wherein the device emits light having a CIE of (0.33±

0.01, 0.33±

0.01).

6. The device of claim 1 wherein the microcavity defined by the first electrode and the second electrode has a finesse of at least 5.

7. The device of claim 1 wherein the microcavity is configured to emit light having a CIE with an x-coordinate less than 0.30 and a y-coordinate of less than 0.40.

8. The device of claim 1 wherein the microcavity is configured to emit light having a CIE with an x-coordinate less than 0.20 and a y-coordinate of less than 0.30.

9. The device of claim 1 wherein the microcavity has an emission spectrum with a single peak in the visible spectrum.

10. The device of claim 2, wherein at least one of the first organic emissive layer and the second organic emissive layer is an organic small molecule layer.

11. The device of claim 3, wherein at least one of the first organic emissive layer and the second organic emissive layer is an organic small molecule layer.

12. The device of claim 4, wherein at least one of the first organic emissive layer and the second organic emissive layer is an organic small molecule layer.

13. The device of claim 5, wherein at least one of the first organic emissive layer and the second organic emissive layer is an organic small molecule layer.

14. The device of claim 1, wherein the second organic emissive layer has an emission spectrum with a single peak in the visible spectrum.

16. The device of claim 14 wherein the device has an operational half-life of at least 25,000 hours at 500 cd/m².

18. The device of claim 14 wherein the device has an operational half-life of at least 40,000 hours at 500 cd/m².

19. The device of claim 18 wherein at least one of the first organic emissive layer and the second organic emissive layer is an organic small molecule layer.

20. The device of claim 14 wherein the device has an operational half-life of at least 25,000 hours at 1500 cd/m².

21. The device of claim 20 wherein at least one of the first organic emissive layer and the second organic emissive layer is an organic small molecule layer.

22. The device of claim 14 wherein the device emits light having a CIE of (0.33±

0.01, 0.33±

0.01).

23. The device of claim 22 wherein at least one of the first organic emissive layer and the second organic emissive layer is an organic small molecule layer.

25. The device of claim 1, wherein said first organic emissive layer emits light having a CIE with an x-coordinate less than 0.30 and a y-coordinate less than about 0.40.

26. The device of claim 25, wherein said second organic emissive layer emits orange light.

15. A device comprising:

an emissive layer comprising;

a single microcavity defined by a first electrode and a second electrode; and

a first organic emissive layer disposed within the single microcavity, said microcavity shifting the CIE coordinates of the emission of the first organic emissive layer such that the device emits light having a CIE of (0.33±

0.05, 0.33±

0.05);

a third electrode disposed adjacent to the second electrode; and

a second organic emissive layer disposed between the second electrode and the third electrode;

wherein;

there are no electrodes between the first electrode and the second electrode;

the second electrode and the third electrode define a standard OLED;

the first organic emissive layer comprising a single first emissive material that emits in a first wavelength region, and the second organic emissive layer comprising a single second emissive material that emits in a second wavelength region, the first wavelength region being shorter than the second wavelength region; and

the combination of the unshifted emission spectrum of the first emissive layer and the emission spectrum of the second emissive layer does not result in emitted light having a CIE of (0.33±

0.05, 0.33±

0.05).

17. The device of claim 15 wherein at least one of the first organic emissive layer and the second organic emissive layer is an organic small molecule layer.

24. The device of claim 15 wherein the second organic emissive layer has an emission spectrum with a single peak in the visible spectrum.

27. The device of claim 15, wherein said first organic emissive layer emits light having a CIE with an x-coordinate less than 0.30 and a y-coordinate less than about 0.40.

28. The device of claim 27, wherein said second organic emissive layer emits orange light.