IP Library › Granted Patent US 10,367,160
Granted Patent B2
US 10,367,160 · App. 15/492,439 · Granted Jul 30, 2019

Light-emitting element

Inventors: Satoshi Seo (Sagamihara, JP); Satoko Shitagaki (Isehara, JP); Nobuharu Ohsawa (Zama, JP); Hideko Inoue (Atsugi, JP); Kunihiko Suzuki (Isehara, JP)
Assignee: Semiconductor Energy Laboratory Co., Ltd.
H01L51/5028C07D409/10C09K11/06H01L51/0072H01L51/0074H01L51/5016H05B33/14C09K2211/1007C09K2211/1011C09K2211/1029C09K2211/1044C09K2211/1088C09K2211/1092C09K2211/185H01L51/006H01L51/0056H01L51/0058H01L51/0059H01L51/0061H01L51/0085
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Quick Facts
Patent No.
US 10,367,160
App. No.
15/492,439
Granted
Jul 30, 2019
Kind
B2
Abstract

A light-emitting element having high external quantum efficiency is provided. A light-emitting element having low drive voltage is provided. Provided is a light-emitting element which includes a light-emitting layer containing a phosphorescent compound, a first organic compound, and a second organic compound between a pair of electrodes. A combination of the first organic compound and the second organic compound forms an exciplex (excited complex). An emission spectrum of the exciplex overlaps with an absorption band located on the longest wavelength side of an absorption spectrum of the phosphorescent compound. A peak wavelength of the emission spectrum of the exciplex is longer than or equal to a peak wavelength of the absorption band located on the longest wavelength side of the absorption spectrum of the phosphorescent compound.

Claims (34)

1. A light-emitting element comprising:

a light-emitting layer comprising a first compound, a second compound, and a guest material,

wherein the first compound and the second compound are capable of forming an exciplex, and

wherein an emission peak wavelength of the exciplex is longer than or equal to a peak wavelength of an absorption band located on the longest wavelength side of an absorption spectrum of the guest material.

2. The light-emitting element according to claim 1 , wherein the guest material is a light-emitting substance.

3. The light-emitting element according to claim 1 , wherein the guest material is a phosphorescent compound.

4. The light-emitting element according to claim 1 , wherein excitation energy of the exciplex is transferred to the guest material so that the guest material emits phosphorescence.

5. The light-emitting element according to claim 1 ,

wherein the first compound has an electron-trapping property, and

wherein the second compound has a hole-trapping property.

6. A light-emitting device comprising the light-emitting element according to claim 1 .

7. A light-emitting element comprising:

a light-emitting layer comprising a first compound, a second compound, and a guest material,

wherein the first compound and the second compound are capable of forming an exciplex, and

wherein an emission peak wavelength of the exciplex is longer than or equal to a peak wavelength of an absorption band located on the longest wavelength side of an absorption spectrum of the guest material and shorter than or equal to an emission peak wavelength of the guest material.

8. The light-emitting element according to claim 7 , wherein the guest material is a light-emitting substance.

9. The light-emitting element according to claim 7 , wherein the guest material is a phosphorescent compound.

10. The light-emitting element according to claim 7 , wherein excitation energy of the exciplex is transferred to the guest material so that the guest material emits phosphorescence.

11. The light-emitting element according to claim 7 ,

wherein the first compound has an electron-trapping property, and

wherein the second compound has a hole-trapping property.

12. A light-emitting device comprising the light-emitting element according to claim 7 .

13. A light-emitting element comprising:

a light-emitting layer comprising a first compound, a second compound, and a guest material,

wherein the first compound and the second compound are capable of forming an exciplex,

wherein an emission spectrum of the exciplex overlaps with an absorption band located on the longest wavelength side of an absorption spectrum of the guest material, and

wherein a difference between a peak wavelength of the emission spectrum of the exciplex and a peak wavelength of an emission spectrum of the guest material is 30 nm or less.

14. The light-emitting element according to claim 13 , wherein the guest material is a light-emitting substance.

15. The light-emitting element according to claim 13 , wherein the guest material is a phosphorescent compound.

16. The light-emitting element according to claim 13 , wherein excitation energy of the exciplex is transferred to the guest material so that the guest material emits phosphorescence.

17. The light-emitting element according to claim 13 ,

wherein the first compound has an electron-trapping property, and

wherein the second compound has a hole-trapping property.

18. A light-emitting device comprising the light-emitting element according to claim 13 .

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 4, 2018
From: SEO, SATOSHI; SHITAGAKI, SATOKO; OHSAWA, NOBUHARU; INOUE, HIDEKO; SUZUKI, KUNIHIKO
To: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
Reel/Frame 047062/0353 →
Priority Claims (1)
JP 2011-064553 · Mar 23, 2011 · national
Continuity (3)
Continuation 14924054 · Oct 27, 2015
Continuation 13419892 · Mar 14, 2012
Related Publication 20170279063A1 · Sep 28, 2017
Cited By (8)
US 12,201,018 US 12,336,369 US 12,400,590 US 12,480,038 US 12,534,459 US 12,581,794 US 12,660,501 US 12,672,453