Triplet-triplet annihilation up-conversation for display and lighting applications

• US 9,140,428 B2
• Filed: 04/18/2014
• Issued: 09/22/2015
• Est. Priority Date: 06/11/2010
• Status: Active Grant

• Current Assignee: Universal Display Corporation
• Original Assignee: Universal Display Corporation
• Inventors: Xia, Chuanjun, Weaver, Michael Stuart, Brooks, Jason
• Primary Examiner(s): Hollweg, Thomas A
• Application Number:
  US14/256,007
• Publication Number:
  US 20140226338A1
• Time in Patent Office: 522 Days
• US Class Current: 1/1
• 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 conversation (TTA-UC) and techniques for operating the same are provided. In particular, the up-conversation layer absorbs light emitted by the OLED device and emits up-converted light with shorter wavelength in response. These devices and techniques may be used to provide improved lifetime for blue emitting devices.

Claims

1. A method of operating a device, comprising:

driving a first organic light emitting device within a first subpixel of a pixel to generate light, the first organic light emitting device comprising a first material that is an emissive material having a first emissive spectrum, the light generated by the first organic light emitting device being absorbed by a first triplet-triplet annihilation up-conversation layer in the pixel, the first triplet-triplet annihilation up-conversion layer comprising a first donor material and a first acceptor material, the first donor material having an absorption spectrum that overlaps with the first emissive spectrum, the generated light causing the wavelength of the light to be shortened via triplet-triplet annihilation up-conversation and emitted by the pixel;

driving a second organic light emitting device in a second subpixel of the pixel, the 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

driving a third organic light emitting device in a third subpixel of the pixel, the 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 method of claim 1, fin her comprising:

absorbing the light generated by the second organic light emitting device in a first down conversion layer to lengthen the light generated by the second organic light emitting device; and

emitting the light generated by the second organic light emitting device having a lengthened wavelength.

3. The method of claim 1, wherein the step of driving the first organic light emitting device to generate light comprises driving the first organic light emitting device to generate light having a peak wavelength of about 500 to about 600 nm.

4. The method of claim 1, further comprising absorbing at least a portion of light generated by the first organic light emitting device with a filter.

5. The method of claim 1, further comprising absorbing at least a portion of light generated by the first organic light emitting device with a microcavity.

6. The method of claim 1, wherein the step of absorbing the light in the first triplet triplet annihilation up-conversion layer comprises absorbing between about 80% and about 100% of light emitted from the first organic light emitting device.

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

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

9. The method of claim 1, wherein the first triplet-triplet annihilation up-conversation layer has a linear or circular light polarization function.

10. The method of claim 1, wherein the first organic light emitting device comprises a first emissive material that comprises a small molecule.

11. The method of claim 1, wherein the first organic light emitting device comprises a first emissive material that comprises a phosphorescent molecule.

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

13. The method of claim 1, wherein the first donor material is selected from the group consisting of

14. The method of claim 1, wherein the first triplet-triplet annihilation up-conversation layer and the organic light emitting device are disposed on the same substrate.

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

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