Organic light-emitting device and display device

• US 10,446,612 B2
• Filed: 11/03/2017
• Issued: 10/15/2019
• Est. Priority Date: 06/01/2017
• Status: Active Grant

• Current Assignee: Wuhan Tianma Micro-Electronics Company Limited (Wuhan Donghu New Technology Development Zone Production Promotion Centre), Wuhan Tianma Microelectronics Company Limited Shanghai Branch
• Original Assignee: Shanghai Tianma AM-OLED Co. Ltd (Tianma Microelectronics Company Limited)
• Inventors: Zhang, Angran
• Primary Examiner(s): Dang, Phuc T
• Application Number:
  US15/802,453
• Publication Number:
  US 20180061901A1
• Time in Patent Office: 711 Days
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 50/131 with spacer layers between the electroluminescent layers
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 59/30 Devices specially adapted for multicolour light emission

Abstract

The present application discloses an organic light-emitting device and a display device. The organic light-emitting device comprises an anode, a cathode, and a first blue light emitting layer, a second blue light emitting layer and a yellow light emitting layer laminated between the anode and the cathode, wherein the yellow light emitting layer is arranged between the cathode and the first blue light emitting layer, and the first blue light emitting layer is arranged between the yellow light emitting layer and the second blue light emitting layer; and the yellow light emitting layer comprises a phosphorescent material, one of the first blue light emitting layer and the second blue light emitting layer comprises a blue fluorescent material, and the other one comprises a blue thermally-activated delayed fluorescent material used as an auxiliary material between a host and a guest.

Claims

1. An organic light-emitting device, comprising an anode, a cathode, and a first blue light emitting layer, a second blue light emitting layer and a yellow light emitting layer laminated between the anode and the cathode, wherein the yellow light emitting layer is arranged between the cathode and the first blue light emitting layer, and the first blue light emitting layer is arranged between the yellow light emitting layer and the second blue light emitting layer;

and

the yellow light emitting layer comprises a phosphorescent material, one of the first blue light emitting layer and the second blue light emitting layer comprises a blue fluorescent material, and another of the first blue light emitting layer and the second blue light emitting layer comprises a blue thermally-activated delayed fluorescent material used as an auxiliary material between a host and a guest,

wherein the yellow light emitting layer comprises a red phosphorescent material and a green phosphorescent material laminated together.

2. The organic light-emitting device according to claim 1, further comprising a plurality of charge generation layers arranged between the yellow light emitting layer and the first blue light emitting layer and between the first blue light emitting layer and the second blue light emitting layer.

3. The organic light-emitting device according to claim 2, wherein the charge generation layers are doped with a p-type material on a side adjacent to the cathode and/or doped with an n-type material on a side adjacent to the anode, and a thickness of the charge generation layers is 10-50 nm.

4. The organic light-emitting device according to claim 3, wherein the p-type material comprises at least one of:

5. The organic light-emitting device according to claim 3, wherein the n-type material comprises at least one of Yb, Mg, Al, Ca and compounds thereof.

6. The organic light-emitting device according to claim 1, wherein the blue thermally-activated delayed fluorescent material comprises at least one of:

acridine, triazine, quinazoline, carbazole and derivatives, dibenzofuran, dibenzothiophene, benzene, biphenyl, naphthalene, and anthracene.

7. The organic light-emitting device according to claim 1, wherein a difference between a singlet energy level and a triplet energy level of the blue thermally-activated delayed fluorescent material is less than 0.15 eV.

8. The organic light-emitting device according to claim 7, wherein a photoluminescence spectrum of the blue thermally-activated delayed fluorescent material has a range of 450-470 nm.

9. The organic light-emitting device according to claim 8, wherein the blue thermally-activated delayed fluorescent material comprises a group having a structure of:

10. The organic light-emitting device according to claim 9, wherein the blue thermally-activated delayed fluorescent material comprises:

11. The organic light-emitting device according to claim 1, wherein the red phosphorescent material has a lowest unoccupied molecular orbital energy level of 2.9-3 eV and a highest occupied molecular orbital energy level of 5-5.8 eV.

12. The organic light-emitting device according to claim 1, wherein the green phosphorescent material has a lowest unoccupied molecular orbital energy level of 2.5-3 eV and a highest occupied molecular orbital energy level of 5-6 eV.

13. The organic light-emitting device according to claim 1, wherein the blue fluorescent material has a lowest unoccupied molecular orbital energy level of 2.8-3 eV and a highest occupied molecular orbital energy level of 5.5-6 eV.

14. The organic light-emitting device according to claim 1, further comprising a plurality of electron transport layers and a plurality of hole transport layers, wherein

the electron transport layers are arranged between the cathode and the yellow light emitting layer, between the yellow light emitting layer and the first blue light emitting layer and between the first blue light emitting layer and the second blue light emitting layer, and the hole transport layers are arranged between the second blue light emitting layer and the anode, between the second blue light emitting layer and the first blue light emitting layer and between the first blue light emitting layer and the yellow light emitting layer.

15. The organic light-emitting device according to claim 14, wherein the hole transport layers comprise a triphenylamine derivative, and the electron transport layers comprise at least one of:

a spirofluorene derivative, a carbazole derivative and a combination thereof having at least one of triazinyl and oxadiazol.

16. The organic light-emitting device according to claim 1, wherein a mass percent of the blue thermally-activated delayed fluorescent material in the first blue light emitting layer or the second blue light emitting layer is 15-35%.

17. The organic light-emitting device according to claim 1, wherein the organic light-emitting device is of a top emission type or a bottom emission type.

18. The organic light-emitting device according to claim 1, wherein the anode comprises a transparent conducting material with a thickness of 10-100 nm;

and the cathode comprises a metal conducting material with a thickness of 10-50 nm.

19. The organic light-emitting device according to claim 18, wherein the anode further comprises a light-tight metal conducting material.

20. A display device, comprising:

an organic light-emitting device, including;

an anode, a cathode, and a first blue light emitting layer, a second blue light emitting layer and a yellow light emitting layer laminated between the anode and the cathode, wherein the yellow light emitting layer is arranged between the cathode and the first blue light emitting layer, and the first blue light emitting layer is arranged between the yellow light emitting layer and the second blue light emitting layer; and

the yellow light emitting layer comprises a phosphorescent material, one of the first blue light emitting layer and the second blue light emitting layer comprises a blue fluorescent material, and another of the first blue light emitting layer and the second blue light emitting layer comprises a blue thermally-activated delayed fluorescent material used as an auxiliary material between a host and a guest,

wherein the yellow light emitting layer comprises a red phosphorescent material and a green phosphorescent material laminated together.