DOUBLE SIDE EMITTING ORGANIC LIGHT EMITTING DIODE AND METHOD OF FABRICATING THE SAME

• US 20080018242A1
• Filed: 07/20/2006
• Published: 01/24/2008
• Est. Priority Date: 07/20/2006
• Status: Abandoned Application

• Current Assignee: Chunghwa Picture Tubes Limited
• Original Assignee: Chunghwa Picture Tubes Limited
• Inventors: Su, Cheng-Feng, Tang, Shuenn-Jiun, Shen, Wen-Jian, Tzen, Chih-Kwang
• Application Number:
  US11/459,005
• Publication Number:
  US 20080018242A1
• Time in Patent Office: Days
• US Class Current: 313/506
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers

Abstract

A method of fabricating a double side emitting organic light emitting diode (OLED) including the following steps is provided. First, a transparent substrate is provided. Then, a first transparent electrode and an organic light emitting layer are sequentially formed on the transparent substrate. Next, a second transparent electrode is formed on the organic light emitting layer. The method of forming the second transparent electrode includes the following steps. A first film composed of alkali metal compound or alkaline-earth metal compound is formed on the organic light emitting layer; a second film composed of metal material is formed on the first film and has a thickness between 20 angstroms and 50 angstroms; a third film composed of transparent conductive material is formed on the second film by using a plasma diffusion deposition process or an ionic thermal evaporation process.

Claims

1. A method of fabricating a double side emitting organic light emitting diode, comprising:

providing a transparent substrate;

forming a first transparent electrode and an organic electroluminescent layer on the transparent substrate sequentially;

forming a second transparent electrode on the organic electroluminescent layer, wherein the step of forming the second transparent electrode comprises;

forming a first film on the organic electroluminescent layer, wherein the first film is made of an alkali metal compound or an alkaline-earth metal compound;

forming a second film on the first film, wherein the second film is made of a metallic material, and a thickness of the second film is between 20 angstroms and 50 angstroms; and

performing a plasma diffusion deposition process or an ionic thermal evaporation process to form a third film on the second film, wherein the third film is made of a transparent conductive material.

2. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein the transparent substrate comprises a glass substrate.

3. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein a material of the first transparent electrode is selected from a group consisting of indium tin oxide, indium zinc oxide, aluminiun zinc oxide, antimony tin oxide, zinc oxide, indium oxide and tin oxide.

4. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein the step of forming the organic electroluminescent layer comprises:

forming a hole injection layer on the first transparent electrode;

forming a hole transport layer on the hole injection layer;

forming a light emitting layer on the hole transport layer;

forming an electron transport layer on the light emitting layer; and

forming an electron injection layer on the electron transport layer.

5. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein a thickness of the first film is between 5 angstroms and 100 angstroms.

6. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein the alkali metal compound comprises a lithium compound.

7. The method of fabricating a double side emitting organic light emitting diode according to claim 6, wherein the lithium compound is selected from a group consisting of lithium fluoride and lithium oxide.

8. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein the metallic material is selected from a group consisting of Al, Au, Ag, Ca, Mg, Mg/Al alloy and Mg/Ag alloy.

9. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein a thickness of the third film is between 500 angstroms and 3000 angstroms.

10. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein a plasma power of the plasma diffusion deposition process is between 5000W and 15000W.

11. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein an operation temperature of the plasma diffusion deposition process is between 20°

C. and 300°

C.

12. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein a plasma gas used in the plasma diffusion deposition process comprises Ar, O₂, N₂ or water vapor.

13. The method of fabricating a double side emitting organic light emitting diode according to claim 1, wherein the transparent conductive material comprises indium tin oxide or indium zinc oxide.

22. The double side emitting organic light emitting diode according to claim 13, wherein a thickness of the third film is between 500 angstroms and 3000 angstroms.

23. The double side emitting organic light emitting diode according to claim 13, wherein the transparent conductive material comprises indium tin oxide or indium zinc oxide.

14. A double side emitting organic light emitting diode, comprising:

a transparent substrate;

a first transparent electrode, disposed on the transparent substrate;

an organic electroluminescent layer, disposed on the first transparent electrode; and

a second transparent electrode, disposed on the organic electroluminescent layer, wherein the second transparent electrode comprises;

a first film, disposed on the organic electroluminescent layer, wherein the first film is made of an alkali metal compound or an alkaline-earth metal compound;

a second film, disposed on the first film, wherein the second film is made of a metallic material, and a thickness of the second film is between 20 angstroms and 50 angstroms; and

a third film, disposed on the second film, wherein the third film is made of a transparent conductive material;

wherein, a driving voltage of the double side emitting organic light emitting diode is smaller than or equal to 5 volt, and a transmission rate of the second transparent electrode is higher than 50%.

15. The double side emitting organic light emitting diode according to claim 14, wherein the transparent substrate comprises a glass substrate.

16. The double side emitting organic light emitting diode according to claim 14, wherein a material of the first transparent electrode is selected from a group consisting of indium tin oxide, indium zinc oxide, aluminium zinc oxide, antimony tin oxide, zinc oxide, indium oxide and tin oxide.

17. The double side emitting organic light emitting diode according to claim 14, wherein the organic electroluminescent layer comprises:

a hole injection layer, disposed on the first transparent electrode;

a hole transport layer, disposed on the hole injection layer;

a light emitting layer, disposed on the hole transport layer;

an electron transport layer, disposed on the light emitting layer; and

an electron injection layer, disposed on the electron transport layer.

18. The double side emitting organic light emitting diode according to claim 14, wherein a thickness of the first film is between 5 angstroms and 100 angstroms.

19. The double side emitting organic light emitting diode according to claim 14, wherein the alkali metal compound comprises a lithium compound.

20. The double side emitting organic light emitting diode according to claim 19, wherein the lithium compound is selected from a group consisting of lithium fluoride and lithium oxide.

21. The double side emitting organic light emitting diode according to claim 14, wherein the metallic material is selected from a group consisting of Al, Au, Ag, Ca, Mg, Mg/Al alloy and Mg/Ag alloy.