Light-emitting element, light-emitting device, electronic device, and lighting device

Patent metadata

Field	Value
Publication number	US-9412962-B2
Application number	US-201313957082-A
Country	US
Kind code	B2
Filing date	Aug 1, 2013
Priority date	Aug 3, 2012
Publication date	Aug 9, 2016
Grant date	Aug 9, 2016

Abstract

A light-emitting element having a long lifetime is provided. A light-emitting element exhibiting high emission efficiency in a high luminance region is provided. A light-emitting element includes a light-emitting layer between a pair of electrodes. The light-emitting layer contains a first organic compound, a second organic compound, and a phosphorescent compound. The first organic compound is represented by a general formula (G0). The molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000. The second organic compound is a compound having an electron-transport property. In the general formula (G0), Ar 1 and Ar 2 each independently represent a fluorenyl group, a spirofluorenyl group, or a biphenyl group, and Ar 3 represents a substituent including a carbazole skeleton.

First claim

The invention claimed is:

1. A light-emitting element comprising, between a pair of electrodes:
a light-emitting layer, the light-emitting layer including:
a first organic compound;
a second organic compound; and
a phosphorescent compound,
wherein the first organic compound is represented by General Formula (G0),

wherein Ar 1 and Ar 2 each independently represent a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted biphenyl group,
wherein Ar 3 represents a substituent including a carbazole skeleton,
wherein a molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000, and
wherein the second organic compound is a compound having an electron-transport property.

2. The light-emitting element according to claim 1 ,
wherein the first organic compound is represented by General Formula (G1),

wherein α represents a substituted or unsubstituted phenylene group or a substituted or unsubstituted biphenyldiyl group,
wherein n represents 0 or 1, and
wherein A represents a substituted or unsubstituted 3-carbazolyl group.

3. The light-emitting element according to claim 1 comprising, between the pair of electrodes:
a hole-transport layer in contact with the light-emitting layer,
wherein the first organic compound is included in the hole-transport layer.

4. The light-emitting element according to claim 1 comprising, between the pair of electrodes:
a hole-transport layer in contact with the light-emitting layer,
wherein the first organic compound, the second organic compound, and the phosphorescent compound are included in the light-emitting layer, and
wherein the first organic compound is included in the hole-transport layer.

5. The light-emitting element according to claim 1 ,
wherein the Ar 1 and the Ar 2 each independently represent a substituted or unsubstituted 2-fluorenyl group, a substituted or unsubstituted spiro-9,9′-bifluoren-2-yl group, or a biphenyl-4-yl group.

6. The light-emitting element according to claim 1 , wherein a combination of the first organic compound and the second organic compound forms an exciplex.

7. A light-emitting device comprising the light-emitting element according to claim 1 in a light-emitting portion.

8. An electronic device comprising the light-emitting device according to claim 7 in a display portion.

9. A lighting device comprising the light-emitting device according to claim 7 in a light-emitting portion.

10. A light-emitting element comprising, between a pair of electrodes:
a light-emitting layer, the light-emitting layer including:
a first organic compound;
a second organic compound; and
a phosphorescent compound,
wherein the first organic compound is represented by General Formula (G2),

wherein Ar 1 and Ar 2 each independently represent a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted spirofluorenyl group, or a substituted or unsubstituted biphenyl group,
wherein Ar 4 represents an alkyl group having 1 to 10 carbon atoms, an unsubstituted phenyl group or a phenyl group having as a substituent at least one alkyl group having 1 to 10 carbon atoms, an unsubstituted biphenyl group or a biphenyl group having as a substituent at least one alkyl group having 1 to 10 carbon atoms, or an unsubstituted terphenyl group or a terphenyl group having as a substituent at least one alkyl group having 1 to 10 carbon atoms,
wherein R 1 to R 4 and R 11 to R 17 each independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms, an unsubstituted phenyl group or a phenyl group having as a substituent at least one alkyl group having 1 to 10 carbon atoms, or an unsubstituted biphenyl group or a biphenyl group having as a substituent at least one alkyl group having 1 to 10 carbon atoms,
wherein a molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000, and
wherein the second organic compound is a compound having an electron-transport property.

11. The light-emitting element according to claim 10 ,
wherein the first organic compound is represented by General Formula (G3),

wherein R 21 to R 25 independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms, an unsubstituted phenyl group or a phenyl group having as a substituent at least one alkyl group having 1 to 10 carbon atoms, or an unsubstituted biphenyl group or a biphenyl group having as a substituent at least one alkyl group having 1 to 10 carbon atoms.

12. The light-emitting element according to claim 10 comprising, between the pair of electrodes:
a hole-transport layer in contact with the light-emitting layer,
wherein the first organic compound is included in the hole-transport layer.

13. The light-emitting element according to claim 10 comprising, between the pair of electrodes:
a hole-transport layer in contact with the light-emitting layer,
wherein the first organic compound, the second organic compound, and the phosphorescent compound are included in the light-emitting layer, and
wherein the first organic compound is included in the hole-transport layer.

14. The light-emitting element according to claim 10 ,
wherein the Ar 1 and the Ar 2 each independently represent a substituted or unsubstituted 2-fluorenyl group, a substituted or unsubstituted spiro-9,9′-bifluoren-2-yl group, or a biphenyl-4-yl group.

15. The light-emitting element according to claim 10 , wherein a combination of the first organic compound and the second organic compound forms an exciplex.

16. A light-emitting device comprising the light-emitting element according to claim 10 in a light-emitting portion.

17. An electronic device comprising the light-emitting device according to claim 16 in a display portion.

18. A lighting device comprising the light-emitting device according to claim 16 in a light-emitting portion.

Assignees

• Semiconductor Energy Lab

Inventors

• Hamada Takao
• Seo Hiromi
• Abe Kanta
• Takeda Kyoko
• Seo Satoshi

Classifications

• C09K11/06

  containing organic luminescent materials · CPC title

• C09K2211/1044

  containing two nitrogen atoms as heteroatoms · CPC title

• C09K11/025

  non-luminescent particle coatings or suspension media · CPC title

• C07D209/86 Primary

  with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the ring system · CPC title

• C09K2211/185

  of the platinum group, i.e. Os, Ir, Pt, Ru, Rh or Pd · CPC title