Light-emitting device and electronic apparatus including the same

Patent metadata

Field	Value
Publication number	US-12356792-B2
Application number	US-202117343549-A
Country	US
Kind code	B2
Filing date	Jun 9, 2021
Priority date	Oct 8, 2020
Publication date	Jul 8, 2025
Grant date	Jul 8, 2025

Abstract

A light-emitting device includes: a first electrode; a second electrode facing the first electrode; and an interlayer between the first electrode and the second electrode and including an emission layer stack, wherein the emission layer stack includes: a first emission layer including a first host and a first dopant; and a second emission layer including a second host, a second dopant, and an electron transport compound, wherein the first host and the second host are different compounds from each other, the first emission layer is in contact with the second emission layer, and the second emission layer is closer to the second electrode than the first emission layer.

First claim

What is claimed is:

1. A light-emitting device comprising:
a first electrode;
a second electrode facing the first electrode;
an interlayer between the first electrode and the second electrode and comprising an emission layer stack,
wherein the emission layer stack comprises:
a first emission layer comprising a first host and a first dopant; and
a second emission layer comprising a second host, a second dopant, and an electron transport compound,
the first host and the second host are different compounds from each other,
the first emission layer is in contact with the second emission layer, and
the second emission layer is closer to the second electrode than the first emission layer.

2. The light-emitting device of claim 1 , wherein the first electrode is an anode,
the second electrode is a cathode, and
the light-emitting device further comprises a hole transport region between the first electrode and the emission layer stack and comprising a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof.

3. The light-emitting device of claim 1 , wherein the first electrode is an anode,
the second electrode is a cathode, and
the light-emitting device further comprises an electron transport region between the second electrode and the emission layer stack and comprising a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

4. The light-emitting device of claim 1 , wherein the emission layer stack emits blue light.

5. The light-emitting device of claim 1 , wherein the first emission layer emits blue light.

6. The light-emitting device of claim 1 , wherein the second emission layer emits blue light.

7. The light-emitting device of claim 1 , wherein a hole mobility (M H ) and an electron mobility (M E ) of the electron transport compound satisfy Formula (1):
M H ≤M E ×0.95  (1).

8. The light-emitting device of claim 1 , wherein the electron transport compound comprises: a CN moiety-containing compound; a triazole moiety-containing compound; an oxadiazole moiety-containing compound; an aromatic imidazole moiety-containing compound; a naphthalene diimide moiety-containing compound; a perylene moiety-containing compound; a boron-containing compound; a compound comprising anthracene and a phosphine oxide moiety; a triazine moiety-containing compound; a pyridine moiety-containing compound; a pyrimidine moiety-containing compound; or a carbazole moiety-containing compound.

9. The light-emitting device of claim 1 , wherein the electron transport compound comprises one of compounds below:

10. The light-emitting device of claim 1 , wherein an amount of the electron transport compound in the second emission layer is equal to or less than 20 wt % based on a total amount of compounds in the second emission layer.

11. The light-emitting device of claim 1 , wherein the first emission layer and the second emission layer emit light by a delayed fluorescence emission mechanism.

12. The light-emitting device of claim 1 , wherein holes injected from the first electrode and electrons injected from the second electrode recombine at an interface between the first emission layer and the second emission layer.

13. The light-emitting device of claim 1 , wherein the emission layer stack comprises a plurality of emission layer stacks.

14. The light-emitting device of claim 13 , wherein a charge generation layer is between adjacent ones of the plurality of emission layer stacks.

15. The light-emitting device of claim 14 , wherein the charge generation layer comprises a quinone derivative, a cyano group-containing compound, or any combination thereof.

16. The light-emitting device of claim 1 , wherein the first host comprises the compound below:

17. The light-emitting device of claim 1 , wherein the second host comprises the compound below:

18. An electronic apparatus comprising the light-emitting device of claim 1 .

19. The electronic apparatus of claim 18 , further comprising:
a thin-film transistor,
wherein the thin-film transistor comprises a source electrode and a drain electrode, and
the first electrode of the light-emitting device is electrically coupled to at least one selected from the source electrode and the drain electrode of the thin-film transistor.

20. The electronic apparatus of claim 18 , further comprising:
a color filter, a color conversion layer, a touch screen layer, a polarizing layer, or any combination thereof.

Assignees

• Samsung Display Co Ltd

Inventors

• Lee Jongwon
• Kang Namsu
• Kim Minkyung
• Park Minho
• Park Huiju
• Lee Dongkyu
• Lee Hyunshik

Classifications

• H10K85/633

  comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom · CPC title

• H10K85/626

  containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene · CPC title

• H10K2101/90

  Multiple hosts in the emissive layer · CPC title

• H10K85/6574

  comprising only oxygen in the heteroaromatic polycondensed ring system, e.g. cumarine dyes · CPC title

• H10K85/654

  comprising only nitrogen as heteroatom (H10K85/652 takes precedence) · CPC title