Light-Emitting Element, Light-Emitting Device, Electronic Device, and Lighting Device

• US 20140034932A1
• Filed: 08/02/2013
• Published: 02/06/2014
• Est. Priority Date: 08/03/2012
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Seo, Hiromi, Seo, Satoshi
• Application Number:
  US13/958,127
• Publication Number:
  US 20140034932A1
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 2101/30 Highest occupied molecular orbital [HOMO], lowest unoccupied molecular orbital [LUMO] or Fermi energy values
• CPC Class Codes: H10K 2101/40 Interrelation of parameters between multiple constituent active layers or sublayers, e.g. HOMO values in adjacent layers
• 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 50/30 Organic light-emitting transistors
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole

Abstract

The light-emitting element has a structure in which a first organic compound and a second organic compound form an exciplex (excited complex) in a light-emitting layer. The S1 level and the T1 level of the formed exciplex are positioned extremely close to each other compared to the S1 level and the T1 level of the respective substances (the first organic compound and the second organic compound) before the formation of the exciplex.

Claims

1. A light-emitting element comprising:

a pair of electrodes; and

a layer between the pair of electrodes,

wherein the layer consists essentially of a first organic compound and a second organic compound,

wherein the first organic compound has an electron-transport property, and

wherein the second organic compound has a p-phenylenediamine skeleton.

2. The light-emitting element according to claim 1, wherein the second organic compound has a 4-(9H-carbazol-9-yl)aniline skeleton.

3. The light-emitting element according to claim 1, wherein the second organic compound has a 9-aryl-9H-carbazol-3-amine skeleton.

4. The light-emitting element according to claim 1, wherein the first organic compound is capable of forming an exciplex with the second organic compound.

5. The light-emitting element according to claim 1, wherein the first organic compound has an electron mobility of 10⁻

6 cm²/Vs or higher.

6. A light-emitting device comprising:

a transistor; and

the light-emitting element according to claim 1, wherein the light-emitting element is electrically connected to the transistor.

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

8. A light-emitting element comprising:

a pair of electrodes; and

a layer between the pair of electrodes,

wherein the layer comprises a first organic compound, a second organic compound, and a compound capable of converting triplet excited energy into light emission,

wherein the first organic compound has an electron-transport property, and

wherein the second organic compound is represented by the following formula;

9. The light-emitting element according to claim 8, wherein the first organic compound is capable of forming an exciplex with the second organic compound.

10. The light-emitting element according to claim 8, wherein the first organic compound has an electron mobility of 10⁻

6 cm²/Vs or higher.

11. The light-emitting element according to claim 8, wherein the compound is an organometallic complex.

12. The light-emitting element according to claim 11, wherein the organometallic complex includes iridium.

13. A light-emitting device comprising:

a transistor; and

the light-emitting element according to claim 8, wherein the light-emitting element is electrically connected to the transistor.

14. A lighting device comprising the light-emitting element according to claim 8.