LIGHT-EMITTING ELEMENT, LIGHT-EMITTING DEVICE, AND ELECTRONIC DEVICE

• US 20090283757A1
• Filed: 05/13/2009
• Published: 11/19/2009
• Est. Priority Date: 05/16/2008
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: SEO, Satoshi, OHSAWA, Nobuharu
• Granted Patent: US 8,247,804 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 50/155 comprising dopants
• CPC Class Codes: H10K 50/165 comprising dopants
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 85/342 comprising iridium
• CPC Class Codes: H10K 85/633 comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom
• CPC Class Codes: H10K 85/636 comprising heteroaromatic 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

Disclosed is a light-emitting element with a good carrier balance and manufacturing method thereof which does not require the formation of the heterostructure. The light-emitting element includes an organic compound film containing a first organic compound as the main component (base material) between an anode and a cathode, wherein the organic compound film is provided in contact with the anode and with the cathode. The first organic compound further includes a light-emitting region to which a light-emitting substance is added and includes a hole-transport region to which a hole-trapping substance is added and/or an electron-transport region to which an electron-trapping substance is added. The hole-transport region is located between the light-emitting region and the anode, and the electron-transport region is located between the light-emitting region and the cathode.

Claims

1. A light-emitting element comprising:

an organic compound film containing a first organic compound between an anode and a cathode,

wherein the organic compound film is provided in contact with the anode and with the cathode,

wherein the organic compound film comprises;

a light-emitting region to which a light-emitting substance is added; and

a hole-transport region to which a hole-trapping substance is added,

wherein the hole-transport region is located between the light-emitting region and the anode, and

wherein a HOMO level of the hole-trapping substance is higher than a HOMO level of the first organic compound by 0.2 eV or more.

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

wherein the light-emitting substance is a phosphorescent compound.

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

wherein the light-emitting element comprises a first region in which an electron-accepting substance is added to the organic compound film, and

wherein the first region is in contact with the anode.

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

wherein the light-emitting element comprises a first region in which an electron-accepting substance is added to the organic compound film,

wherein the first region is in contact with the anode, and

wherein the electron-accepting substance is selected from vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

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

wherein the light-emitting element comprises a second region in which an electron-donating substance is added to the organic compound film, and

wherein the second region is in contact with the cathode.

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

wherein the light-emitting element comprises a second region in which an electron-donating substance is added to the organic compound film,

wherein the second region is in contact with the cathode, and

wherein the electron-donating substance comprises an alkali metal, an alkaline-earth metal, and a rare metal.

7. A light-emitting element comprising:

an organic compound film containing a first organic compound between an anode and a cathode,

wherein the organic compound film is provided in contact with the anode and with the cathode,

wherein the organic compound film comprises;

a light-emitting region to which a light-emitting substance is added; and

an electron-transport region to which an electron-trapping substance is added,

wherein the electron-transport region is located between the light-emitting region and the cathode, and

wherein a LUMO level of the electron-trapping substance is lower than a LUMO level of the first organic compound by 0.2 eV or more.

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

wherein the light-emitting substance is a phosphorescent compound.

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

wherein the light-emitting element comprises a first region in which an electron-accepting substance is added to the organic compound film, and

wherein the first region is in contact with the anode.

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

wherein the light-emitting element comprises a first region in which an electron-accepting substance is added to the organic compound film,

wherein the first region is in contact with the anode, and

wherein the electron-accepting substance is selected from vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

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

wherein the light-emitting element comprises a second region in which an electron-donating substance is added to the organic compound film, and

wherein the second region is in contact with the cathode.

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

wherein the light-emitting element comprises a second region in which an electron-donating substance is added to the organic compound film,

wherein the second region is in contact with the cathode, and

wherein the electron-donating substance comprises an alkali metal, an alkaline-earth metal, and a rare metal.

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

wherein the light-emitting element comprises a hole-transport region in which a hole-trapping substance is added to the first organic compound,

wherein the hole-transport region is located between the light-emitting region and the anode, and

wherein a HOMO level of the hole-trapping substance is higher than a HOMO level of the first organic compound by 0.2 eV or more.

14. A light-emitting element comprising:

an organic compound film containing a first organic compound between an anode and a cathode,

wherein the organic compound film is provided in contact with the anode and with the cathode,

wherein the organic compound film comprises;

a light-emitting region to which a light-emitting substance is added; and

a first charge generation region being in contact with the anode,

wherein the first charge generation region comprises;

an N-type region in which an electron-donating substance is added to the first organic compound; and

a P-type region to which an electron-accepting substance is added, and

wherein the N-type region is in contact with the anode.

15. The light-emitting element according to claim 14,

wherein the light-emitting substance is a phosphorescent compound.

16. The light-emitting element according to claim 14,

wherein the electron-donating substance comprises an alkali metal, an alkaline-earth metal, and a rare metal.

17. The light-emitting element according to claim 14,

wherein the electron-accepting substance is selected from vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

18. The light-emitting element according to claim 14,

wherein the light-emitting element comprises a hole-transport region in which an hole-trapping substance is added to the organic compound film, and

wherein the hole-transport region is located between the first charge generation region and the light-emitting region, and

wherein a HOMO level of the hole-trapping substance is higher than a HOMO level of the first organic compound by 0.2 eV or more.

19. The light-emitting element according to claim 14,

wherein the light-emitting element comprises an electron-transport region in which an electron-trapping substance is added to the organic compound film,

wherein the electron-transport region is located between the light-emitting region and the anode, and

wherein a LUMO level of the electron-trapping substance is lower than a LUMO level of the first organic compound by 0.2 eV or more.

20. The light-emitting element according to claim 14,

wherein the light-emitting element comprises a second charge generation region which is in contact with the cathode,

wherein the second charge generation region comprises the N-type region and the P-type region, and

wherein the P-type region is in contact with the cathode.

21. A light-emitting element comprising:

an organic compound film containing a first organic compound between an anode and a cathode,

wherein the organic compound film is provided in contact with the anode and with the cathode,

wherein the organic compound film comprises;

a light-emitting region to which a light-emitting substance is added; and

a first charge generation region being in contact with the cathode,

wherein the first charge generation region comprises;

an N-type region in which an electron-donating substance is added to the first organic compound; and

a P-type region to which an electron-accepting substance is added, and

wherein the P-type region is in contact with the cathode.

22. The light-emitting element according to claim 21,

wherein the light-emitting substance is a phosphorescent compound.

23. The light-emitting element according to claim 21,

wherein the electron-donating substance comprises an alkali metal, an alkaline-earth metal, and a rare metal.

24. The light-emitting element according to claim 21,

wherein the electron-accepting substance is selected from vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide.

25. The light-emitting element according to claim 21,

wherein the light-emitting element comprises a hole-transport region in which an hole-trapping substance is added to the organic compound film,

wherein the hole-transport region is located between the anode and the light-emitting region, and

wherein a HOMO level of the hole-trapping substance is higher than a HOMO level of the first organic compound by 0.2 eV or more.

26. The light-emitting element according to claim 21,

wherein the light-emitting element comprises an electron-transport region in which an electron-trapping substance is added to the organic compound film, and

wherein the electron-transport region is located between the light-emitting region and the first charge generation region, and

wherein a LUMO level of the electron-trapping substance is lower than a LUMO level of the first organic compound by 0.2 eV or more.