ORGANIC ELECTROLUMINESCENCE DISPLAY DEVICE

• US 20190326542A1
• Filed: 04/12/2019
• Published: 10/24/2019
• Est. Priority Date: 04/24/2018
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: YANG, Jungjin, KIM, Myunghwan, KIM, Seohyun, KIM, Ji-young, PARK, Jinwoo, SONG, Wonjun, YOO, Taewoong, YOUN, Soojung, LEE, Kwanhee, LEE, Seokjae
• Granted Patent: US 11,043,649 B2
• Time in Patent Office: Days
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/16 Electron transporting layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels

Abstract

An organic electroluminescence display device includes: a substrate; a first electrode including a first sub-electrode and a second sub-electrode spaced apart from each other and on the substrate; a first light emitting unit on the first electrode; a charge generation unit on the first light emitting unit; a second light emitting unit on the charge generation unit; and a second electrode on the second light emitting unit, wherein the first light emitting unit comprises a first light emitting layer correspondingly on the first sub-electrode; and a second light emitting layer correspondingly on the second sub-electrode, wherein the second light emitting unit comprises a third light emitting layer correspondingly on the first light emitting layer; and a fourth light emitting layer correspondingly on the second light emitting layer.

Claims

1. An organic electroluminescence display device comprising:

a substrate;

a first electrode including a first sub-electrode and a second sub-electrode spaced apart from each other and on the substrate;

a first light emitting unit on the first electrode;

a charge generation unit on the first light emitting unit;

a second light emitting unit on the charge generation unit; and

a second electrode on the second light emitting unit,

wherein the first light emitting unit comprises a first light emitting layer correspondingly on the first sub-electrode; and

a second light emitting layer correspondingly on the second sub-electrode,

wherein the second light emitting unit comprises a third light emitting layer correspondingly on the first light emitting layer; and

a fourth light emitting layer correspondingly on the second light emitting layer,

wherein the charge generation unit comprises;

an n-type charge generation layer on the first light emitting layer and the second light emitting layer; and

a p-type charge generation layer including a first p-type charge generation layer on the n-type charge generation layer and correspondingly on the first light emitting layer, and

a second p-type charge generation layer correspondingly on the second light emitting layer.

2. The device of claim 1, wherein

the first light emitting layer and the third light emitting layer emit light of a same color,

the second light emitting layer and the fourth light emitting layer emit light of a same color, and

the first light emitting layer and the second light emitting layer emit light of different colors.

3. The device of claim 1, wherein the first p-type charge generation layer and the second p-type charge generation layer are spaced apart from each other.

4. The display of claim 1, wherein

the first electrode further comprises a third sub-electrode spaced apart from the first sub-electrode and the second sub-electrode,

the first light emitting unit further comprises a fifth light emitting layer correspondingly on the third sub-electrode,

the second light emitting unit further comprises a sixth light emitting layer correspondingly on the fifth light emitting layer, and

the p-type charge generation layer further comprises a third p-type charge generation layer correspondingly on the fifth light emitting layer.

5. The display device of claim 4, wherein the fifth light emitting layer and the sixth light emitting layer are layers that emit the same color, and the fifth light emitting layer is a layer that emits a different color from each of the first light emitting layer and the second light emitting layer.

6. The device of claim 4, wherein

each of the first light emitting layer and the third light emitting layer is a red light emitting layer,

each of the second light emitting layer and the fourth light emitting layer is a green light emitting layer, and

each of the fifth light emitting layer and the sixth light emitting layer is a blue light emitting layer.

7. The device of claim 4, wherein a thickness of the first light emitting layer is greater than a thickness of the second light emitting layer, and the thickness of the second light emitting layer is greater than a thickness of the fifth light emitting layer, and

a thickness of the third light emitting layer is greater than a thickness of the fourth light emitting layer and the thickness of the fourth light emitting layer is greater than a thickness of the sixth light emitting layer.

8. The device of claim 6, wherein the fifth light emitting layer is a layer that emits a first blue light having a first central wavelength, and the sixth light emitting layer is a layer that emits a second blue light having a second central wavelength different from the first central wavelength.

9. The device of claim 1, wherein the charge generation unit further comprises a buffer layer between the n-type charge generation layer and the p-type charge generation layer.

10. The device of claim 1, wherein the n-type charge generation layer has a step difference and each of the first p-type charge generation layer and the second p-type charge generation layer has no step difference.

11. The device of claim 1, wherein

the first light emitting unit further comprises:

a first hole transport region below the first light emitting layer and the second light emitting layer, and on the first sub-electrode and the second sub-electrode; and

a first electron transport region on the first light emitting layer and on the second light emitting layer and below the charge generation unit,

wherein

the second light emitting unit further comprises;

a second hole transport region below the third light emitting layer and the fourth light emitting layer, and on the charge generation unit; and

a second electron transport region on the third light emitting layer and the fourth light emitting layer, and below the second electrode.

12. The device of claim 1, wherein the n-type charge generation layer is doped with an inorganic material, and the p-type charge generation layer is doped with an organic material or an inorganic material.

13. The device of claim 12, wherein the p-type charge generation layer is doped with a metal halide.

14. The device of claim 1, wherein a thickness of the first p-type charge generation layer and a thickness of the second p-type charge generation layer are different from each other.

15. The device of claim 1, wherein

the n-type charge generation layer comprises an n-type dopant and the p-type charge generation layer comprises a p-type dopant,

a doping ratio of the n-type dopant is 1 wt % to 10 wt %,

a doping ratio of the p-type dopant is 2 wt % to 15 wt %, and

the doping ratios of the p-type dopants in the first p-type charge generation layer and the second p-type charge generation layer are different from each other.

16. An organic electroluminescence display device comprising:

a substrate where a first light emitting region, a second light emitting region, and a third light emitting region spaced apart from each other are defined;

a first electrode including a first sub-electrode on the substrate and corresponding to the first light emitting region;

a second sub-electrode corresponding to the second light emitting region; and

a third sub-electrode corresponding to the third light emitting region;

a first light emitting unit including a first sub-light emitting layer on the first electrode and corresponding to the first light emitting region;

a second sub-light emitting layer corresponding to the second light emitting region; and

a third sub-light emitting layer corresponding to the third light emitting region,

a charge generation unit on the first light emitting unit;

a second light emitting unit including a fourth sub-light emitting layer corresponding to the first light emitting region;

a fifth sub-light emitting layer corresponding to the second light emitting region; and

a sixth sub-light emitting layer corresponding to the third light emitting region, and the second light emitting unit is on the charge generation unit; and

a second electrode on the second light emitting unit,

wherein the charge generation unit comprises;

an n-type charge generation layer commonly on the first light emitting region, the second light emitting region, and the third light emitting region; and

a p-type charge generation layer including a first p-type charge generation layer disposed corresponding to the first light emitting region;

a second p-type charge generation layer corresponding to the second light emitting region; and

a third p-type charge generation layer corresponding to the third light emitting region, and the p-type charge generation layer is on the n-type charge generation layer.

17. The device of claim 16, wherein the first p-type charge generation layer, the second p-type charge generation layer, and the third p-type charge generation layer are spaced apart from each other.

18. The device of claim 16, wherein

each of the first sub-light emitting layer and the fourth sub-light emitting layer is a red light emitting layer,

each of the second sub-light emitting layer and the fifth sub-light emitting layer is a green light emitting layer, and

each of the third sub-light emitting layer and the sixth sub-light emitting layer is a blue light emitting layer.

19. The device of claim 16, wherein a thickness of the first sub-light emitting layer is greater than a thickness of the second sub-light emitting layer, and the thickness of the second sub-light emitting layer is greater than a thickness of the third light emitting layer, and

a thickness of the fourth sub-light emitting layer is greater than a thickness of the fifth sub-light emitting layer, and the thickness of the fifth sub-light emitting layer is greater than a thickness of the sixth sub-light emitting layer.

20. The device of claim 16, wherein the charge generation unit further comprises a buffer layer disposed between the n-type charge generation layer and the p-type charge generation layer.

21. The device of claim 16, wherein the n-type charge generation layer has a step difference, and

each of the first p-type charge generation layer, the second p-type charge generation layer, and the third p-type charge generation layer has no step difference.

22. The device of claim 16, wherein the n-type charge generation layer is doped with an inorganic material, and the p-type charge generation layer is doped with an organic material.

23. The device of claim 16, wherein a thickness of the first p-type charge generation layer, a thickness of the second p-type charge generation layer, and a thickness of the third p-type charge generation layer are different from each other.

24. The device of claim 16, wherein

the n-type charge generation layer comprises an n-type dopant and the p-type charge generation layer comprises a p-type dopant,

a doping ratio of the n-type dopant is 1 wt % to 10 wt %,

a doping ratio of the p-type dopant is 2 wt % to 15 wt %, and

the doping ratios of the p-type dopants in the first p-type charge generation layer, the second p-type charge generation layer, and the third p-type charge generation layer are different from each other.