Triplet-Triplet annihilation up conversion (TTA-UC) for display and lighting applications

• US 8,742,657 B2
• Filed: 10/11/2010
• Issued: 06/03/2014
• Est. Priority Date: 06/11/2010
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Xia, Chuanjun, Brooks, Jason, Weaver, Michael S
• Primary Examiner(s): Hollweg, Thomas A
• Application Number:
  US12/901,901
• Publication Number:
  US 20110304263A1
• Time in Patent Office: 1,331 Days
• Field of Search: 313/504, 313/501
• US Class Current: 313/504
• CPC Class Codes: F21V 9/08 for producing coloured light, e.g. monochromatic; for reducing intensity of light with provision for controlling the colour F21V9/40
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 85/151 Copolymers
• CPC Class Codes: H10K 85/341 Transition metal complexes, e.g. Ru(II)polypyridine complexes H10K85/331 takes precedence
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/344 comprising ruthenium
• CPC Class Codes: H10K 85/346 comprising platinum
• CPC Class Codes: H10K 85/615 Polycyclic condensed aromatic hydrocarbons, e.g. anthracene
• CPC Class Codes: H10K 85/622 containing four rings, e.g. pyrene
• CPC Class Codes: H10K 85/623 containing five rings, e.g. pentacene
• CPC Class Codes: H10K 85/657 Polycyclic condensed heteroaromatic hydrocarbons

Abstract

Novel devices comprising a layer including compounds that are capable of triplet triplet annihilation up conversion (TTA-UC). In particular, the up-conversion layer absorbs light emitted by the OLED device and emits up-converted light with shorter wavelength in response. These devices may be used to provide improved lifetime for blue emitting devices.

Claims

1. A first device, comprising:

a pixel comprising;

a first subpixel comprising;

a first organic light emitting device comprising a first material that is an emitting material having a first emissive spectrum; and

a first triplet-triplet annihilation up conversion layer disposed adjacent to the first organic light emitting device such that light emitted by the organic light emitting device is incident on the first triplet-triplet annihilation up conversion layer, the first triplet-triplet annihilation up conversion layer comprising a first donor material and a first acceptor material, wherein the first donor material has an absorption spectrum that overlaps with the first emissive spectrum;

a second subpixel comprising a second organic light emitting device comprising a second material that is an emitting material having a second emissive spectrum with a peak wavelength of about 500 nm to about 600 nm; and

a third subpixel comprising a third organic light emitting device comprising a third material that is an emitting material having a third emissive spectrum with a peak wavelength of about 600 nm to about 700 nm.

2. The device of claim 1, wherein the third subpixel further comprises:

a first down conversion layer disposed adjacent to the third organic light emitting device such that light emitted by the third organic light emitting device is incident on the first down conversion layer.

3. The device of claim 1, wherein the second subpixel does not include an up-conversion layer or a down conversion layer.

4. The device of claim 1, wherein the first material has an emissive spectrum having a peak wavelength of about 500 nm to about 600 nm.

5. The device of claim 1, wherein the second subpixel does not comprise an up-conversion layer or a down conversion layer.

6. The device of claim 1 or 5, wherein the first triplet-triplet annihilation up-conversion layer absorbs between about 80 percent and about 100 percent of the light emitted from the organic light emitting device.

7. The device of claim 1 or 5, wherein the device further comprises at least one filter that absorbs light having a peak wavelength of about 500 nm to about 600 nm.

9. The device of claim 1 or 5, wherein the device absorbs 99 percent of the emitted light emitted by the first material.

10. The device of claim 1, wherein the first subpixel has an emissive spectrum that has a peak wavelength of about 400 nm to about 500 nm.

11. The device of claim 1, wherein the first material has an emissive spectrum having a peak wavelength of about 500 nm to about 600 nm;

wherein, in the first subpixel;

the first material emits light having a peak wavelength of about 500 to about 600 nm; and

the first triplet-triplet annihilation up-conversion layer absorbs light having a peak wavelength of about 500 nm to about 600 nm and emits light having a peak wavelength of about 400 nm to about 500 nm;

such that the first subpixel emits light having a peak wavelength of about 400 nm to about 500 nm;

wherein the second subpixel does not include an up-conversion or a down conversion layer, and the second subpixel emits light having a wavelength of about 500 nm to about 600 nm; and

wherein the third subpixel includes a down conversion layer, and the down conversion layer absorbs light having a peak wavelength of about 500 nm to about 600 nm and emits light having a peak wavelength of about 600 nm to about 700 nm;

such that the third subpixel emits light having a peak wavelength of about 600 nm to about 700 nm.

12. The device of claim 11, wherein the first material, the second material, and the third material are the same material.

13. The device of claim 1, wherein the first organic light emitting device is capable of emitting a first spectrum of light having a first peak wavelength when voltage is applied to the device, and the up-conversion layer is capable of absorbing the first spectrum of light and emitting a second spectrum of light with a second peak wavelength, wherein the second peak wavelength is shorter than the first peak wavelength.

14. The device of claim 1, wherein the first triplet-triplet annihilation up-conversion layer absorbs between about 20 percent and about 80 percent of the light emitted by the first material.

15. The device of claim 1, wherein the device has CIE coordinates of x=0.10-0.40, y=0.05-0.40.

16. The device of claim 1, wherein the device has a CRI of about 80 to about 100.

17. The device of claim 1, wherein the first triplet-triplet annihilation up-conversion layer is a solution.

18. The device of claim 1, wherein the first triplet-triplet annihilation up conversion layer is a solid film.

19. The device of claim 1, wherein the first organic light emitting device is a green organic light emitting device or red organic light emitting device.

20. The device of claim 1, wherein the first material emits light having CIE coordinates of within a seven step McAdam ellipse centered on the black body curve with a correlated color temperature (CCT) in the range of 2500-7400K , and wherein the first device emits light having CIE coordinates of within a seven step McAdam ellipse centered on the black body curve with a correlated color temperature (CCT) at least 50K higher than that of the emission of the first material.

21. The device of claim 1, wherein the first material emits light having a peak wavelength of about 500 nm to about 700 nm, and the first device emits light having CIE coordinates of within a seven step McAdam ellipse centered on the black body curve with a correlated color temperature (CCT) in the range of 2500-7000K.

22. The device of claim 1, further comprising a filter deposited over the organic light emitting device.

23. The device of claim 1, wherein the device is an area emitting device.

24. The device of claim 1, wherein the first triplet-triplet annihilation up-conversion layer and the organic light emitting device are deposited on the same substrate.

25. The device of claim 1, wherein the first triplet-triplet annihilation up-conversion layer is vertically-stacked upon the organic light emitting device.

26. The device of claim 1, wherein the first triplet-triplet annihilation up-conversion layer and the organic light emitting device are positioned side by side.

27. The device of claim 1, wherein the first device is a display.

28. The device of claim 1, wherein the first device is suitable for general illumination purposes.

29. The device of claim 1, wherein the first triplet-triplet annihilation up-conversion layer has a linear or circular light polarization function.

30. The device of claim 1, wherein the first material is a small molecule.

31. The device of claim 1, wherein the first material is a phosphorescent molecule.

32. The device of claim 1, wherein the first donor materials are selected from the group consisting of:

8. The device of claim for 5, wherein the device further comprises at least one microcavity that absorbs light having a peak wavelength of about 500 nm to about 600 nm.