Light-emitting element, display device, and method for manufacturing light-emitting element

Patent metadata

Field	Value
Publication number	US-9825250-B2
Application number	US-201414897021-A
Country	US
Kind code	B2
Filing date	Jun 30, 2014
Priority date	Jul 4, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

An organic EL element includes: a first electrode that is a metal layer; a transparent conductive layer containing indium zinc oxide; and a light-emitting layer, wherein the first electrode, the transparent conductive layer, and the light-emitting layer are stacked, and a ratio of zinc to indium in a vicinity of an interface of the transparent conductive layer is lower than or equal to 0.25, the interface being closer to the light-emitting layer.

First claim

The invention claimed is:

1. A light-emitting element comprising:
a metal layer;
a transparent conductive layer containing indium zinc oxide; and
a light-emitting layer,
wherein the metal layer, the transparent conductive layer, and the light-emitting layer are stacked, and
a ratio of zinc to indium in a surface layer of the transparent conductive layer is lower than or equal to 0.25, the surface layer facing the light-emitting layer.

2. The light-emitting element according to claim 1 ,
wherein the transparent conductive layer is approximately 5 nm or less in thickness.

3. The light-emitting element according to claim 1 ,
wherein the metal layer contains aluminum.

4. The light-emitting element according to claim 1 , further comprising
a hole injection layer is disposed between the transparent conductive layer and the light-emitting layer.

5. The light-emitting element according to claim 4 ,
wherein the hole injection layer contains an organic amine.

6. The light-emitting element according to claim 4 , further comprising
an electron block layer is disposed between the hole injection layer and the light-emitting layer.

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

8. A method for manufacturing a light-emitting element, the method comprising:
forming a metal layer;
forming a transparent conductive layer above the metal layer, the transparent conductive layer containing indium zinc oxide;
oxidizing the metal layer; and
forming a light-emitting layer above the transparent conductive layer,
wherein a ratio of zinc to indium in a surface layer of the transparent conductive layer is lower than or equal to 0.25, the surface layer facing the light-emitting layer.

9. The method according to claim 8 ,
wherein the oxidizing includes baking the metal layer or irradiating the metal layer with ultraviolet rays.

10. The method according to claim 8 ,
wherein the oxidizing is performed after the forming of the transparent conductive layer.

11. The method according to claim 8 ,
wherein the oxidizing is performed between the forming of the metal layer and the forming of the transparent conductive layer.

12. The method according to claim 8 ,
wherein in the forming of the transparent conductive layer, the transparent conductive layer is formed with a thickness of approximately 5 nm or less.

13. The method according to claim 8 ,
wherein the metal layer contains aluminum.

14. The method according to claim 8 , further comprising
forming a hole injection layer between the forming of the transparent conductive layer and the forming of the light-emitting layer.

15. The method according to claim 14 ,
wherein the hole injection layer contains an organic amine.

16. The method according to claim 14 , further comprising
forming an electron block layer between the forming of the hole injection layer and the forming of the light-emitting layer.

17. The light-emitting element according to claim 1 , wherein
the indium zinc oxide contained in the transparent conductive layer is in contact with the metal layer,
the metal layer contains a metallic element having a lower ionization potential than zinc, and
the transparent conductive layer has a thickness of 5 nm or less.

18. The light-emitting element according to claim 1 , further comprising
forming a zinc segregation layer in the surface layer of the transparent conductive layer, the zinc segregation layer being positioned closer to the light-emitting layer than a remaining portion of the surface layer.

19. The light-emitting element according to claim 1 , wherein
the transparent conductive layer is formed directly on the metal layer, and
the metal layer contains an aluminum alloy.

20. The light-emitting element according to claim 1 , wherein
wherein the ratio of zinc to indium in the surface layer of the transparent conductive layer is higher than or equal to 0.17.

21. The light-emitting element according to claim 1 , wherein
the transparent conductive layer permits passing of certain wavelengths of light while blocking others to modify a color of the light passing therethrough.

Assignees

• Joled Inc

Inventors

• Yokota Kazuhiro
• Abe Yuuki
• Shinokawa Yasuharu
• Mishima Kosuke

Classifications

• H01L51/56

  Electricity · mapped topic

• H01L51/5218 Primary

  Electricity · mapped topic

• H01L51/5096

  Electricity · mapped topic

• H01L51/5088

  Electricity · mapped topic

• H01L2251/308

  Electricity · mapped topic