ORGANIC LIGHT EMITTING ELEMENT, ORGANIC LIGHT EMITTING DISPLAY DEVICE, AND METHOD OF MANUFACTURING THE ORGANIC LIGHT EMITTING DISPLAY DEVICE

• US 20140183471A1
• Filed: 12/18/2013
• Published: 07/03/2014
• Est. Priority Date: 12/28/2012
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Heo, JoonYoung
• Granted Patent: US 9,263,502 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 59/351 comprising more than three subpixels, e.g. red-green-blue-white [RGBW]
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]

Abstract

A white organic light emitting element, a white organic light emitting display device, and a method of manufacturing the white organic light emitting element are provided. The organic light emitting element includes a multi-layered emission layer structure. The multi-layered emission layer structure includes a first electroluminescent layer and a second electroluminescent layer that are arranged to overlap at first area of the white organic light emitting element. The lights from the first and second electroluminescent layers collectively form white light. Among the first and second electroluminescent layers, one of the EL layers is extended out to the second area of the white organic light emitting element. A plurality of color filter elements are used to filter the white light to generate colored lights at the corresponding sub pixel regions.

Claims

1. A display device, comprising:

a multi-layered emission layer structure having a blue electroluminescent (EL) layer configured to emit blue light and a complementary EL layer configured to emit light having a color complementary to the blue light that collectively form white light;

a red color filter element configured to filter the white light to generate red light;

a green color filter element configured to filter the white light to generate green light; and

a plurality of pixels including a red pixel configured to transmit the red light from the red color filter element, a green pixel configured to transmit the green light from the green color filter element, and a blue pixel configured to transmit the blue light emitted from the blue EL layer.

2. The display device of claim 1, wherein the blue EL layer is disposed in the plurality of pixels, and wherein the complementary EL layer is disposed in the plurality of pixels excluding the blue pixel.

3. The display device of claim 1, wherein the blue EL layer is disposed on the complementary EL layer in the red and green pixels.

4. The display device of claim 1, wherein the complementary EL layer is disposed on the blue complementary EL layer in the red and green pixels.

5. The display device of claim 1, wherein each of the plurality of pixels includes an individually addressable anode.

6. The display device of claim 1, further comprising a charge generation layer interposed between the blue EL layer and the complementary light EL layer.

7. The display device of claim 1, wherein the complementary EL layer includes a host doped with a red dopant and a green dopant.

8. The display device of claim 1, wherein the complementary EL layer comprises a stack of a red EL layer and a green EL layer.

9. The display device of claim 1, wherein the complementary EL layer comprises a stack of an EL layer doped with a red phosphor dopant and an EL layer doped with a yellow phosphor dopant, and wherein the blue light EL layer comprises an EL layer doped with a blue fluorescent dopant.

10. The display device of claim 1, wherein the plurality of pixels includes a white pixel configured to transmit the white light from the multi-layered emission layer structure.

11. The display device of claim 1, further comprising a blue color filter element configured to filter the blue light emitted from the blue EL layer to adjust the blue light, wherein the blue pixel is configured to transmit the blue light from the blue EL layer filtered by the blue color filter element.

12. A white organic light emitting diode (OLED) device, comprising:

a plurality of individually addressable anodes, said plurality of individually addressable anodes comprising one or more anodes disposed in a first area of the white OLED device and one or more anodes disposed in a second area of the white OLED device;

a blue electroluminescent (EL) layer configured to emit substantially blue light, the blue EL layer being disposed on the first and second areas of the white OLED device;

a complementary EL layer configured to emit light complementary to the substantially blue light, the complementary EL layer being disposed on the first area of the white OLED device such that the first area of the white OLED device emits a combination of light from the blue EL layer and the complementary EL layer and the second area of the white OLED device emits the blue light from the blue EL layer disposed in the second area;

a cathode disposed in both the first area and the second area of the white OLED device; and

at least one color filter element configured to filter at least some of the combined light emitted from the first area and transmit colored light corresponding to the color filter element.

13. The white OLED device of claim 12, wherein the blue EL layer is disposed on at least one anode in the first area and at least one anode in the second area of the white OLED device, and wherein the complementary EL layer is disposed on at least one anode excluding the anode disposed in the second area.

14. The white OLED device of claim 12, wherein the substantially blue light from the blue EL layer of the second area is substantially unaffected by the complementary EL layer.

15. The white OLED device of claim 12, wherein the light emitted from the first and second areas of the white OLED device exits the white OLED device through the anodes.

16. The white OLED device of claim 12, wherein the light emitted from the first and second areas of the white OLED device exits the white OLED device through the cathode.

17. The white OLED device of claim 12, wherein at least some portion of the blue EL layer and at least some portion of the complementary EL layer are overlapped in the first area of the display device.

18. The white OLED device of claim 12, wherein the complementary EL layer covers the blue EL layer disposed in the first area of the white OLED device.

19. The white OLED device of claim 12, wherein the blue EL layer covers the complementary EL layer disposed in the first area of the white OLED device.

20. The white OLED device of claim 12, wherein said at least one color filter element includes a red color filter element and a green color filter element configured to filter the light emitted from the first area to transmit red and green colored light, respectively.

21. The white OLED device of claim 12, comprising a white pixel, a red pixel, and a green pixel configured to transmit light emitted from the first area of the display device, and a blue sub pixel configured to transmit light emitted from the second area, wherein the white sub pixel transmits the light emitted from the first area without being filtered by said at least one color filter element, wherein the red sub pixel transmits the light emitted from the first area of the display device that is filtered through a red color filter element, wherein the green sub pixel transmits the light emitted from the first area of the display device that is filtered through a green color filter element, and wherein the blue sub pixel transmits the light from the second area of the display device without being filtered through.

22. A method of manufacturing a display device, comprising:

forming a plurality of anodes on a substrate;

forming both a complementary electroluminescent (EL) layer and a blue EL layer, the complementary EL layer formed in a first area of the display device, the blue EL layer formed in the first area and extending beyond the complementary EL layer over a second area of the display device;

forming a cathode such that the blue EL layer and the complementary EL layer are disposed between the anode and the cathode; and

forming one or more color filter elements within at least a portion of the first area of the display device.

23. The method of claim 22, wherein forming one or more color filter elements includes forming a red color filter element and a green color filter element in the first area of the display device.

24. The method of claim 23, wherein forming both the blue and complementary EL layers comprises:

forming the complementary EL layer in the first area;

forming the blue EL layer in the first and second areas, wherein the blue EL layer in the first area is formed on the complementary EL layer in the first area.

25. The method of claim 23, wherein forming both the blue and complementary EL layers comprises:

forming the blue EL layer in both the first area and the second area;

forming a photoresist over the second area;

forming the complementary EL layer over the blue EL layer and the photoresist; and

stripping the photoresist.

26. The method of claim 25, wherein the photoresist is developed using a developing solution containing fluorine.

27. The method of claim 25, wherein the photoresist is stripped using a stripper containing fluorine.

28. The method of claim 23, wherein forming the complementary EL layer comprises depositing an EL layer having a host doped with a red dopant and a green dopant.

29. The method of claim 23, wherein forming the complementary EL layer comprises depositing a stacked structure having a yellow EL layer and a green EL layer.

30. The method of claim 23, wherein forming the complementary EL layer comprises depositing a stacked structure having a red EL layer and a green EL layer.

31. The method of claim 23, wherein forming the blue EL layer comprises depositing an EL layer doped with a blue fluorescent dopant, and wherein forming the complementary EL layer comprises depositing a stacked structure of a red EL layer doped with a red phosphor dopant and a yellow EL layer doped with a yellow phosphor dopant.

32. The method of claim 23, wherein forming the blue EL layer comprises depositing an EL layer doped with a blue fluorescent dopant, and wherein forming the complementary EL layer comprises depositing a stacked structure of a green EL layer doped with a green phosphor dopant and a yellow EL layer doped with a yellow phosphor dopant.

33. A display device, comprising:

a multi-layered emission layer structure having at least a part being configured to emit a first colored light from a principal EL layer and at least at one other part configured to emit a combination of light from the principal EL layer and the complementary EL layer, in which the complementary EL layer being configured to emit light complementary relative to the first colored light; and

one or more of color filter elements for filtering the combination of light from the principal EL layer and the complementary EL layer, wherein at least one of a red pixel, a green pixel and a blue pixel transmits the first colored light and at least one other pixel transmits the combination of light from the principal EL layer and the complementary EL layer filtered through said color filter element.