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

Patent metadata

Field	Value
Publication number	US-10069076-B2
Application number	US-201615228557-A
Country	US
Kind code	B2
Filing date	Aug 4, 2016
Priority date	Aug 3, 2012
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

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), Ar1 and Ar2 each independently represent a fluorenyl group, a spirofluorenyl group, or a biphenyl group, and Ar3 represents a substituent including a carbazole skeleton.

First claim

The invention claimed is:

1. A light-emitting element comprising:
a hole transport layer comprising a first organic compound; and
a light-emitting layer over the hole transport layer, the light-emitting layer comprising a second organic compound, a third organic compound, and a phosphorescent compound,
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 1,
wherein A represents a substituted or unsubstituted 3-carbazolyl group,
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 a molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000,
wherein the third organic compound is a π-electron deficient heteroaromatic compound,
wherein a HOMO level of the third organic compound is lower than a HOMO level of the second organic compound, and
wherein a LUMO level of the third organic compound is lower than a LUMO of the second organic compound.

2. The light-emitting element according to claim 1 ,
wherein the first organic compound is represented by General Formula (G3),

and
wherein R 1 to R 4 , R 11 to R 17 , and R 21 to R 25 each independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms, an unsubstituted phenyl group, a phenyl group substituted by at least one alkyl group having 1 to 10 carbon atoms, an unsubstituted biphenyl group, or a biphenyl substituted by at least one alkyl group having 1 to 10 carbon atoms.

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

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

5. An electronic device comprising the light-emitting device according to claim 4 in a display portion.

6. A lighting device comprising the light-emitting device according to claim 4 in a light-emitting portion.

7. A light-emitting element comprising:
a hole transport layer comprising a first organic compound; and
a light-emitting layer over the hole transport layer, the light-emitting layer comprising a second organic compound, a third organic compound, and a phosphorescent compound,
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 1,
wherein A represents a substituted or unsubstituted 3-carbazolyl group,
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 a molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000,
wherein a combination of the second organic compound and the third organic compound forms an exciplex
wherein the third organic compound is a η-electron deficient heteroaromatic compound,
wherein a HOMO level of the third organic compound is lower than a HOMO level of the second organic compound, and
wherein a LUMO level of the third organic compound is lower than a LUMO of the second organic compound.

8. The light-emitting element according to claim 7 , wherein the first organic compound is represented by General Formula (G3),

and
wherein R 1 to R 4 , R 1 to R 17 , and R 21 to R 25 each independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms, an unsubstituted phenyl group, a phenyl group substituted by at least one alkyl group having 1 to 10 carbon atoms, an unsubstituted biphenyl group, or a biphenyl substituted by at least one alkyl group having 1 to 10 carbon atoms.

9. The light-emitting element according to claim 7 ,
wherein the Ar 1 and the Ar 2 each independently represent a substituted or unsubstituted spiro-9,9′-bifluoren-2-yl group, or a biphenyl-4-yl group.

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

11. An electronic device comprising the light-emitting device according to claim 10 in a display portion.

12. A lighting device comprising the light-emitting device according to claim 10 in a light-emitting portion.

13. A light-emitting element comprising:
a hole transport layer comprising a first organic compound; and
a light-emitting layer over the hole transport layer, the light-emitting layer comprising a second organic compound, a third organic compound, and a phosphorescent compound,
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,
wherein A represents a substituted or unsubstituted 3-carbazolyl group,
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 a molecular weight of the first organic compound is greater than or equal to 500 and less than or equal to 2000,
wherein a combination of the second organic compound and the third organic compound forms an exciplex,
wherein an emission spectrum of the exciplex overlaps with an absorption band of the phosphorescent compound which is located on the longest wavelength side
wherein the third organic compound is a π-electron deficient heteroaromatic compound,
wherein a HOMO level of the third organic compound is lower than a HOMO level of the second organic compound, and
wherein a LUMO level of the third organic compound is lower than a LUMO of the second organic compound.

14. The light-emitting element according to claim 13 , wherein the first organic compound is represented by General Formula (G3),

and
wherein R 1 to R 4 , R 11 to R 17 , and R 21 to R 25 each independently represent hydrogen, an alkyl group having 1 to 10 carbon atoms, an unsubstituted phenyl group, a phenyl group substituted by at least one alkyl group having 1 to 10 carbon atoms, an unsubstituted biphenyl group, or a biphenyl substituted by at least one alkyl group having 1 to 10 carbon atoms.

15. The light-emitting element according to claim 13 ,
wherein the Ar 1 and the Ar 2 each independently represent a substituted or unsubstituted spiro-9,9′-b

Assignees

• Semiconductor Energy Lab

Inventors

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

Classifications

• C09K11/025

  non-luminescent particle coatings or suspension media · CPC title

• C09K11/06

  containing organic luminescent materials · CPC title

• C09K2211/1044

  containing two nitrogen atoms as heteroatoms · 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