Light-emitting element

• US 9,653,705 B2
• Filed: 10/20/2015
• Issued: 05/16/2017
• Est. Priority Date: 10/23/2014
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Uesaka, Shogo, Sasaki, Toshiki, Ohsawa, Nobuharu
• Primary Examiner(s): Dulka, John P
• Assistant Examiner(s): Sylvia, Christina
• Application Number:
  US14/887,980
• Publication Number:
  US 20160118625A1
• Time in Patent Office: 574 Days
• CPC Class Codes: H10K 2102/00 Constructional details relating to the organic devices covered by this subclass
• CPC Class Codes: H10K 2102/101 comprising transparent conductive oxides [TCO]
• CPC Class Codes: H10K 50/13 comprising stacked EL layers within one EL unit
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 50/814 combined with auxiliary electrodes, e.g. ITO layer combined with metal lines
• CPC Class Codes: H10K 50/818 Reflective anodes, e.g. ITO combined with thick metallic layers
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/351 comprising more than three subpixels, e.g. red-green-blue-white [RGBW]

Abstract

An electrode layer having high reflectance and a light-emitting element having high emission efficiency are provided. The light-emitting element includes a first electrode layer, a second electrode layer, and an EL layer between the first electrode layer and the second electrode layer. The first electrode layer includes a conductive layer and an oxide layer in contact with the conductive layer. The conductive layer has a function of reflecting light. The oxide layer includes In and M (M represents Al, Si, Ti, Ga, Y, Zr, Sn, La, Ce, Nd, or Hf). A content of the M in the oxide layer is higher than or equal to a content of the In.

Claims

1. A light-emitting element comprising:

a first electrode layer;

a second electrode layer; and

an EL layer between the first electrode layer and the second electrode layer,

wherein the first electrode layer comprising;

a conductive layer; and

an oxide layer in contact with the conductive layer,

wherein the conductive layer has a function of reflecting light,

wherein the oxide layer includes In and M (M represents Al, Si, Ti, Ga, Y, Zr, Sn, La, Ce, Nd, or Hf), and

wherein a content of the M in the oxide layer is higher than or equal to a content of the In.

2. The light-emitting element according to claim 1, further comprising a third electrode layer, wherein the EL layer is interposed between the second electrode layer and the third electrode layer.

3. The light-emitting element according to claim 2, wherein the third electrode layer includes an oxide whose composition is different from the composition of the oxide layer.

4. The light-emitting element according to claim 2, wherein an emission color of light from a first region between the first electrode layer and the second electrode layer can be different from an emission color of light from a second region between the second electrode layer and the third electrode layer.

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

wherein the EL layer comprises a first light-emitting layer and a second light-emitting layer,

wherein the first light-emitting layer includes a first compound having a function of emitting light, and

wherein the second light-emitting layer includes a second compound having a function of emitting light.

6. The light-emitting element according to claim 1, wherein the conductive layer includes Al or Ag.

7. The light-emitting element according to claim 1, wherein the oxide layer includes In, Ga, and Zn.

8. A light-emitting element comprising:

a first electrode layer;

an EL layer over the first electrode layer; and

a second electrode layer over the EL layer,

wherein the first electrode layer comprising;

a conductive layer; and

an oxide layer on and in contact with the conductive layer,

wherein the conductive layer has a function of reflecting light,

wherein the oxide layer includes In and M (M represents Al, Si, Ti, Ga, Y, Zr, Sn, La, Ce, Nd, or Hf), and

wherein a content of the M in the oxide layer is higher than or equal to a content of the In.

9. The light-emitting element according to claim 8, further comprising a third electrode layer, wherein the EL layer is over the third electrode layer.

10. The light-emitting element according to claim 9, wherein the third electrode layer includes an oxide whose composition is different from the composition of the oxide layer.

11. The light-emitting element according to claim 9, wherein an emission color of light from a first region between the first electrode layer and the second electrode layer can be different from an emission color of light from a second region between the second electrode layer and the third electrode layer.

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

wherein the EL layer comprises a first light-emitting layer and a second light-emitting layer,

wherein the first light-emitting layer includes a first compound having a function of emitting light, and

wherein the second light-emitting layer includes a second compound having a function of emitting light.

13. The light-emitting element according to claim 8, wherein the conductive layer includes Al or Ag.

14. The light-emitting element according to claim 8, wherein the oxide layer includes In, Ga, and Zn.

15. A light-emitting element comprising:

a first electrode layer;

an EL layer on and in contact with the first electrode layer; and

a second electrode layer on and in contact with the EL layer,

wherein the first electrode layer comprising;

a conductive layer; and

an oxide layer on and in contact with the conductive layer,

wherein the conductive layer has a function of reflecting light,

wherein the oxide layer includes In and M (M represents Al, Si, Ti, Ga, Y, Zr, Sn, La, Ce, Nd, or Hf), and

wherein a content of the M in the oxide layer is higher than or equal to a content of the In.

16. The light-emitting element according to claim 15, further comprising a third electrode layer, wherein the EL layer is on and in contact with the third electrode layer.

17. The light-emitting element according to claim 16, wherein the third electrode layer includes an oxide whose composition is different from the composition of the oxide layer.

18. The light-emitting element according to claim 16, wherein an emission color of light from a first region between the first electrode layer and the second electrode layer can be different from an emission color of light from a second region between the second electrode layer and the third electrode layer.

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

wherein the EL layer comprises a first light-emitting layer and a second light-emitting layer,

wherein the first light-emitting layer includes a first compound having a function of emitting light, and

wherein the second light-emitting layer includes a second compound having a function of emitting light.

20. The light-emitting element according to claim 15, wherein the conductive layer includes Al or Ag.