Light-emitting element and light-emitting device

• US 8,878,159 B2
• Filed: 06/08/2011
• Issued: 11/04/2014
• Est. Priority Date: 09/30/2004
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Kumaki, Daisuke, Seo, Satoshi
• Primary Examiner(s): Cao, Phat X
• Application Number:
  US13/155,693
• Publication Number:
  US 20110233597A1
• Time in Patent Office: 1,245 Days
• Field of Search: 257/13, 257/40, 257/79, 257/E39.007
• US Class Current: 257/13
• CPC Class Codes: H10K 2102/101 comprising transparent conductive oxides [TCO]
• CPC Class Codes: H10K 2102/102 comprising tin oxides, e.g. fluorine-doped SnO2
• CPC Class Codes: H10K 2102/103 comprising indium oxides, e.g. ITO
• CPC Class Codes: H10K 2102/351 Thickness
• CPC Class Codes: H10K 50/14 Carrier transporting layers
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/165 comprising dopants
• CPC Class Codes: H10K 50/805 Electrodes
• 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 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/805 Electrodes
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

It is an object of the present invention to provide a light-emitting element having a layer containing a light-emitting material and a transparent conductive film between a pair of electrodes, in which electric erosion of the transparent conductive film and metal can be prevented, and also to provide a light-emitting device using the light-emitting element. According to one feature of the invention, a light-emitting element includes a first layer 102 containing a light-emitting material, a second layer 103 containing a material having a donor level, a third layer 104 including a transparent conductive film, and a fourth layer 105 containing a hole-transporting medium between a first electrode 101 and a second electrode 106, in which the first layer 102, the second layer 103, the third layer 104, the fourth layer 105, and the second electrode 106 are provided sequentially, in which the second electrode 106 has a layer containing metal.

Claims

1. A light-emitting device comprising:

an anode;

a first layer over the anode, the first layer comprising a light-emitting material;

a second layer over and in direct contact with the first layer;

a third layer over and in direct contact with the second layer, the third layer comprising a transparent conductive film;

a fourth layer over the third layer, the fourth layer comprising an organic compound doped with an electron-receiving material to the organic compound; and

a cathode over and in direct contact with the fourth layer, the cathode comprising a metal,

wherein each of the second layer and the third layer has a single layer structure,

wherein the second layer comprises a material selected from zinc oxide, tin oxide, titanium oxide, zinc sulfide, zinc selenide, and zinc telluride, and

wherein the transparent conductive film comprises a material selected from the group consisting of tin oxide, indium oxide, zinc oxide, zinc oxide containing gallium, and molybdenum oxide.

2. The light-emitting device according to claim 1, wherein the organic compound is a hole-transporting material.

3. The light-emitting device according to claim 2, wherein the hole-transporting material is a material having an aromatic-amine skeleton.

4. The light-emitting device according to claim 1, wherein the electron-receiving material is a metal oxide.

5. The light-emitting device according to claim 4, wherein the metal oxide is selected from molybdenum oxide, vanadium oxide, and rhenium oxide.

6. The light-emitting device according to claim 1, wherein the first layer has a multilayer structure.

7. The light-emitting device according to claim 1, further comprising a fifth layer between the anode and the first layer.

8. The light-emitting device according to claim 7, wherein the fifth layer comprises a hole-transporting material.

9. The light-emitting device according to claim 1, further comprising a filter on the side where light is extracted.

10. An electronic device of which display portion is equipped with the light-emitting device according to claim 1.

11. A light-emitting device comprising:

an anode;

a first layer over the anode, the first layer comprising a light-emitting material;

a second layer over and in direct contact with the first layer and comprising a first organic compound doped with an electron-supplying material to the first organic compound;

a third layer over and in direct contact with the second layer, the third layer comprising a transparent conductive film;

a fourth layer over the third layer, the fourth layer comprising a second organic compound doped with an electron-receiving material to the second organic compound; and

a cathode over and in direct contact with the fourth layer, the cathode comprising a metal,

wherein each of the second layer and the third layer has a single layer structure,

wherein the transparent conductive film comprises a material selected from the group consisting of tin oxide, indium oxide, zinc oxide, zinc oxide containing gallium, and molybdenum oxide.

12. The light-emitting device according to claim 11, wherein the first organic compound is an electron-transporting material.

13. The light-emitting device according to claim 12, wherein the electron-transporting material is a metal complex having a ligand including a π

-conjugated skeleton.

14. The light-emitting device according to claim 11, wherein the electron-supplying material is selected from an alkali metal, an alkali-earth metal, and a rare-earth metal.

15. The light-emitting device according to claim 11, wherein the second organic compound is a hole-transporting material.

16. The light-emitting device according to claim 15, wherein the hole-transporting material is a material having an aromatic-amine skeleton.

17. The light-emitting device according to claim 11, wherein the electron-receiving material is a metal oxide.

18. The light-emitting device according to claim 17, wherein the metal oxide is selected from molybdenum oxide, vanadium oxide, and rhenium oxide.

19. The light-emitting device according to claim 11, wherein the first layer has a multilayer structure.

20. The light-emitting device according to claim 11, further comprising a fifth layer between the anode and the first layer.

21. The light-emitting device according to claim 20, wherein the fifth layer comprises a hole-transporting material.

22. The light-emitting device according to claim 11, further comprising a filter on the side where light is extracted.

23. An electronic device of which display portion is equipped with the light-emitting device according to claim 11.