Organic light-emitting device, a manufacturing method and display device

Patent metadata

Field	Value
Publication number	US-12324299-B2
Application number	US-202117519722-A
Country	US
Kind code	B2
Filing date	Nov 5, 2021
Priority date	Mar 29, 2021
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

An organic light-emitting device, a manufacturing method and a display device are provided. The organic light-emitting device includes: a first electrode and a second electrode that are arranged oppositely; at least two light-emitting layers located between the first electrode and the second electrode, the at least two light-emitting layers include a first light-emitting layer and a second light-emitting layer that are stacked alternately. The first light-emitting layer is a blue light-emitting layer, the first light-emitting layer is doped with a first dopant material, and the second light-emitting layer is doped with a second dopant material. The first dopant material includes a blue light-emitting material with triplet-triplet annihilation effect, and the triplet energy level of the first dopant material is higher than the triplet energy level of the second dopant material.

First claim

What is claimed is:

1. An organic light-emitting device, comprising:
a first electrode and a second electrode arranged oppositely;
at least two light-emitting layers between the first electrode and the second electrode, the at least two light-emitting layers comprise: a first light-emitting layer and a second light-emitting layer that are stacked alternately;
the first light-emitting layer is a blue light-emitting layer, and the first light-emitting layer is doped with a first dopant material;
the second light-emitting layer is doped with a second dopant material;
the first dopant material comprises a blue light-emitting material with triplet-triplet annihilation effect, and the triplet energy level of the first dopant material is higher than the triplet energy level of the second dopant material,
wherein the organic light-emitting device further comprises a reflective layer located on a side of the first electrode away from the second electrode; and the second electrode is a semi-transparent electrode,
wherein a distance Lo between the reflective layer and the semi-transparent electrode satisfies: k·λ/2=La+Lc+n 1 ·Lo,
wherein La is a penetration depth on the reflective layer side due to the reflective phase shift of the reflective layer, Lc is a penetration depth on the second electrode side due to the reflective phase shift of the second electrode, k is an integer, λ is a peak wavelength of a blue light emitted by the first light-emitting layer, and n 1 is a refractive index of all layers between the reflective layer and the semi-transparent electrode.

2. The organic light-emitting device according to claim 1 , wherein the second light-emitting layer is selected from a group consisting of a yellow light-emitting layer, a red light-emitting layer, and an orange light-emitting layer.

3. The organic light-emitting device according to claim 1 , wherein the at least two light-emitting layers have a layer number of an odd number.

4. The organic light-emitting device according to claim 3 , wherein the at least two light-emitting layers comprise light-emitting layers selected from a group consisting of:
the first light-emitting layer, the second light-emitting layer, and the first light-emitting layer that are stacked sequentially; and
the second light-emitting layer, the first light-emitting layer, and the second light-emitting layer that are stacked sequentially.

5. The organic light-emitting device according to claim 1 , wherein the triplet energy level of the first dopant material is greater than or equal to 2.2 eV.

6. The organic light-emitting device according to claim 1 , wherein the first dopant material is at least one selected from the group consisting of compounds represented by any of the following structural formulas:

7. The organic light-emitting device according to claim 1 , wherein the second dopant material is at least one selected from the group consisting of compounds represented by any of the following structural formulas:

8. The organic light-emitting device according to claim 1 , wherein:
a distance Lo 1 between the reflective layer and the first light-emitting layer closest to the reflective layer among the at least two light-emitting layers satisfies: k·λ/4=La+n 2 ·Lo 1 ,
wherein La is a penetration depth of the reflective layer side due to a reflection phase shift of the reflective layer, k is an integer, λ is a peak wavelength of a blue light emitted by the first light-emitting layer, and n 2 is a refractive index of all layers between the reflective layer and the first light-emitting layer.

9. The organic light-emitting device of claim 1 , further comprising: at least one selected from a group consisting of a hole injection layer, a hole transport layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

10. The organic light-emitting device according to claim 1 , wherein:
a light-outgoing layer is provided on the second electrode.

11. The organic light-emitting device according to claim 1 , wherein the first light-emitting layer further comprises a first host material, the first dopant material is doped in the first host material, and the first host material is selected from one or a mixture of several of the compounds represented by any of the following structural formulas:

12. The organic light-emitting device according to claim 1 , wherein the second light-emitting layer further comprises a second host material, the second dopant material is doped in the second host material, and the second host material is selected from one or a mixture of several of the compounds represented by any of the following structural formulas:

13. The organic light-emitting device according to claim 9 , wherein the organic light-emitting device is a white light organic light-emitting device, and the white light organic light-emitting device comprises the first electrode, a hole injection layer, a hole transport layer, the second light-emitting layer, the first light-emitting layer, the second light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, the second electrode and a light-outgoing layer sequentially arranged on a substrate.

14. A display device comprising the organic light-emitting device of claim 1 .

15. The display device according to claim 14 , wherein the organic light-emitting device is a white light organic light-emitting device, the display device has a display panel of an organic light-emitting diode display panel, and the organic light-emitting diode display panel comprises a plurality of the white light organic light-emitting devices.

16. The display device according to claim 14 , wherein the organic light-emitting device is a white light organic light-emitting device, the display device comprises a liquid crystal display panel and a backlight source for providing a backlight for the liquid crystal display panel, and the backlight source comprises a plurality of the white light organic light-emitting devices.

17. A method for preparing an organic light-emitting device, comprising the following steps:
forming a first electrode on a substrate;
forming at least two light-emitting layers on the substrate comprising the first electrode, the at least two light-emitting layers comprising: a first light-emitting layer and a second light-emitting layer that are stacked alternately;
forming a second electrode on the substrate comprising the at least two light-emitting layers;
wherein, the first light-emitting layer is a blue light-emitting layer, the blue light-emitting layer is doped with a first dopant material; the second light-emitting layer is doped with a second dopant material; the first dopant material comprises a blue light-emitting material with triplet-triplet annihilation effect; and the triplet energy level of the first dopant material is higher than the triplet energy level of the second dopant material,
wherein the method further comprises: forming a reflective layer located on a side of the first electrode away from the second electrode; wherein the second electrode

Assignees

• Boe Technology Group Co Ltd

Inventors

• Jing Shu
• Du Xiaobo
• Zhang Zhihui

Classifications

• H10K59/876

  comprising a resonant cavity structure, e.g. Bragg reflector pair · CPC title

• H10K2101/90

  Multiple hosts in the emissive layer · CPC title

• H10K2101/10

  Triplet emission · CPC title

• H10K71/00

  Manufacture or treatment specially adapted for the organic devices covered by this subclass · CPC title

• H10K50/125

  specially adapted for multicolour light emission, e.g. for emitting white light · CPC title