Benzo[a] Anthracene Compound, Light-Emitting Element, Display Device, Electronic Device, and Lighting Device

• US 20160126463A1
• Filed: 10/29/2015
• Published: 05/05/2016
• Est. Priority Date: 10/31/2014
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KADOMA, Hiroshi, SUZUKI, Tsunenori, SEO, Satoshi, OGITA, Kaori
• Granted Patent: US 10,236,448 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C07D 209/86 with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the ring system
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1011 Condensed systems
• CPC Class Codes: C09K 2211/1029 containing one nitrogen atom as the heteroatom
• CPC Class Codes: H10K 2101/10 Triplet emission
• CPC Class Codes: H10K 2101/27 Combination of fluorescent and phosphorescent emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/121 for assisting energy transfer, e.g. sensitization
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 59/32 Stacked devices having two or more layers, each emitting at different wavelengths
• CPC Class Codes: H10K 85/622 containing four rings, e.g. pyrene
• CPC Class Codes: H10K 85/626 containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• CPC Class Codes: H10K 85/633 comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole

Abstract

Provided is a light-emitting element with high emission efficiency including a fluorescent material as a light-emitting substance. In a light-emitting element including a pair of electrodes and an EL layer between the pair of electrodes, a delayed fluorescence component due to triplet-triplet annihilation accounts for 20% or more of light emitted from the EL layer, and the light has at least one emission spectrum peak in the blue wavelength range. The EL layer includes an organic compound in which an energy difference between the lowest singlet excited energy level and the lowest triplet excited energy level is 0.5 eV or more. The EL layer includes a benzo[a]anthracene compound.

Claims

1. A light-emitting element comprising:

a pair of electrodes; and

an EL layer between the pair of electrodes,

wherein a delayed fluorescence component due to triplet-triplet annihilation accounts for 20% or more of light emitted from the EL layer, and the light has at least one emission spectrum peak in a blue wavelength range.

2. The light-emitting element according to claim 1, wherein the blue wavelength range is greater than or equal to 400 nm and less than or equal to 550 nm.

3. The light-emitting element according to claim 1, wherein the EL layer comprises a guest material capable of emitting fluorescence.

4. The light-emitting element according to claim 3, wherein the guest material comprises a pyrene skeleton.

5. A light-emitting element comprising:

a pair of electrodes; and

an EL layer between the pair of electrodes,

wherein the EL layer comprises an organic compound in which an energy difference between a lowest singlet excited energy level and a lowest triplet excited energy level is 0.5 eV or more, and

wherein a delayed fluorescence component accounts for 20% or more of light emitted from the EL layer, and the light has at least one emission spectrum peak in a blue wavelength range.

6. The light-emitting element according to claim 5, wherein the blue wavelength range is greater than or equal to 400 nm and less than or equal to 550 nm.

7. The light-emitting element according to claim 5, wherein, in the organic compound, a difference in equivalent energy value between a peak wavelength of a fluorescence spectrum and a peak wavelength of a phosphorescence spectrum is 0.5 eV or more.

8. The light-emitting element according to claim 5, wherein the organic compound comprises a benzo[a]anthracene skeleton.

9. The light-emitting element according to claim 5, wherein the EL layer comprises a guest material capable of emitting fluorescence.

10. The light-emitting element according to claim 9, wherein the guest material comprises a pyrene skeleton.

11. A benzo[a]anthracene compound represented by a formula (G1),

12. The benzo[a]anthracene compound according to claim 11,

wherein the arylene group includes one or more substituents.

13. The benzo[a]anthracene compound according to claim 12,

wherein the substituents of the arylene group are bonded to each other to form a ring.

14. A light-emitting element comprising:

a pair of electrodes; and

an EL layer between the pair of electrodes,

wherein the EL layer comprises the benzo[a]anthracene compound according to claim 11.

15. The light-emitting element according to claim 14, wherein the EL layer comprises a guest material capable of emitting fluorescence.

16. The light-emitting element according to claim 15, wherein the guest material is configured to exhibit an emission spectrum peak in a blue wavelength range.

17. The light-emitting element according to claim 15, wherein the guest material is capable of emitting delayed fluorescence.

18. The light-emitting element according to claim 15, wherein the guest material comprises a pyrene skeleton.

19. The benzo[a]anthracene compound according to claim 11,

wherein the benzo[a]anthracene compound is represented by a formula (G2), and

20. The benzo[a]anthracene compound according to claim 19, wherein Ar is any of a substituted or unsubstituted phenylene group and a substituted or unsubstituted biphenyldiyl group.

21. The benzo[a]anthracene compound according to claim 19, wherein Ar is a substituted or unsubstituted m-phenylene group.

22. The benzo[a]anthracene compound according to claim 19,

wherein the benzo[a]anthracene compound is represented by a formula (G4), and

23. The benzo[a]anthracene compound according to claim 22, wherein the benzo[a]anthracene compound is represented by a formula (100),

24. The benzo[a]anthracene compound according to claim 11,

wherein the benzo[a]anthracene compound is represented by a formula (G3), and

25. The benzo[a]anthracene compound according to claim 24, wherein Ar is any of a substituted or unsubstituted phenylene group and a substituted or unsubstituted biphenyldiyl group.

26. The benzo[a]anthracene compound according to claim 24, wherein Ar is a substituted or unsubstituted nm-phenylene group.

27. The benzo[c]anthracene compound represented according to claim 24,

wherein the benzo[a]anthracene compound is represented by a formula (G5), and