Organic electroluminescence display device having anode and drain sealing structure and a method for fabricating thereof

• US 7,911,128 B2
• Filed: 08/18/2005
• Issued: 03/22/2011
• Est. Priority Date: 12/29/2004
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Bang, Hee-Suk, Han, Chang-Wook, Ahn, Tae-Joon
• Primary Examiner(s): MacChiarolo; Peter J
• Assistant Examiner(s): GREEN, TRACIE Y
• Application Number:
  US11/207,228
• Publication Number:
  US 20060138942A1
• Time in Patent Office: 2,042 Days
• Field of Search: 313501-512
• US Class Current: 313/504
• CPC Class Codes: H10K 59/1216 the pixel elements being capacitors
• CPC Class Codes: H10K 59/127 comprising two substrates, e.g. display comprising OLED array and TFT driving circuitry on different substrates

Abstract

An organic electroluminescence display device and a fabrication method thereof is described. The organic electroluminescence display device includes first and second substrates. A cathode including a transparent conductive material and a thin metal film, an organic electroluminescence (EL) layer formed on the cathode, and an anode formed on the organic EL layer are formed on the first substrate. A driving transistor that contains a drain electrode is formed on the second substrate. The first and second substrates are bonded to each other such that the drain electrode contacts the anode.

Claims

1. An organic light emitting device comprising:

a first substrate;

a cathode on the first substrate, wherein the cathode comprises a transparent conductive material layer on the first substrate and a metal film formed on the transparent conductive material layer, and wherein the metal film transmits light incident from following organic electroluminescence (EL) layer and has a work function smaller than that of the following organic electroluminescence (EL) layer, and the cathode has a step;

an organic electroluminescence (EL) layer on the metal film of the cathode, wherein the organic EL layer comprises an electron injection layer and an electron transfer layer that transmit electrons supplied from the cathode;

a hole injection layer and a hole transfer layer that transmit holes supplied from an anode; and

an organic light-emitting layer between the electron transfer layer and the hole transfer layer;

the anode on the organic EL layer, the cathode disposed closer to the first substrate than the anode;

a second substrate corresponding to the first substrate; and

a driving transistor containing a drain electrode on the second substrate, wherein the drain electrode comes in contact with the anode

to bond the first substrate and the second substrate to each other.

2. The device of claim 1, wherein the metal film has a thickness of less than about 50 angstroms.

3. The device of claim 2, wherein the metal film has a thickness of about 10 angstroms.

4. The device of claim 1, wherein the metal film has a thickness of about 100 angstroms to about 300 angstroms.

5. The device of claim 4, wherein the metal film directly contacts the first substrate.

6. The device of claim 1, wherein the anode comprises a metal film having a work function larger than that of the cathode.

7. The device of claim 1, wherein the anode comprises a multilayer structure.

8. The device of claim 7, wherein an outermost layer of the multilayer structure comprises a metal film having a work function larger than that of at least one of the other layers of the multilayer metal structure.

9. The device of claim 1, wherein the anode comprises an opaque thin film.

10. The device of claim 1, wherein the anode has a protrusion that contacts the drain electrode of the driving transistor.

11. The device of claim 10, wherein the protrusion in the anode is formed by the step on the cathode.

12. An organic light emitting device comprising:

a first substrate;

a cathode on the first substrate, wherein the cathode comprises a transparent conductive material layer on the first substrate and a metal film formed on the transparent conductive material layer, and wherein the metal film transmits light incident from following organic electroluminescence (EL) layer and has a work function smaller than that of the following organic electroluminescence (EL) layer, and the cathode has a step;

an organic electroluminescence (EL) layer on the metal film of the cathode, wherein the organic EL layer comprises an electron injection layer and an electron transfer layer that transmit electrons supplied from the cathode;

a hole injection layer and a hole transfer layer that transmit holes supplied from an anode; and

an organic light-emitting layer between the electron transfer layer and the hole transfer layer;

the anode on the organic EL layer, the cathode disposed closer to the first substrate than the anode, wherein the anode has a protrusion formed by the step on the cathode;

a second substrate corresponding to the first substrate; and

a driving transistor containing a drain electrode on the second substrate, wherein the drain electrode comes in contact with the anode

to bond the first substrate and the second substrate to each other.

13. The device of claim 12, wherein the metal film has a thickness of less than about 50 angstroms.

14. The device of claim 13, wherein the metal film has a thickness of about 10 angstroms.

15. The device of claim 12, wherein the metal film has a thickness of about 100 angstroms to about 300 angstroms.

16. The device of claim 12, wherein the metal film directly contacts the first substrate.

17. The device of claim 12, wherein the anode comprises a metal film having a work function larger than that of the cathode.

18. The device of claim 12, wherein the anode comprises a multilayer structure.

19. The device of claim 18, wherein an outermost layer of the multilayer structure comprises a metal film having a work function larger than that of at least one of the other layers of the multilayer metal structure.

20. The device of claim 12, wherein the anode comprises an opaque thin film.

21. An organic light emitting device comprising:

a first substrate;

a cathode on the first substrate, wherein the cathode comprises a transparent conductive material layer on the first substrate and a metal film formed on the transparent conductive material layer, and wherein the metal film transmits light incident from following organic electroluminescence (EL) layer and has a work function smaller than that of the following organic electroluminescence (EL) layer, and the metal film is formed in the range of about 10 to 50 angstroms to transmit light, the cathode has a step;

an organic electroluminescence (EL) layer on the metal film of the cathode, wherein the organic EL layer comprises an electron injection layer and an electron transfer layer that transmit electrons supplied from the cathode;

a hole injection layer and a hole transfer layer that transmit holes supplied from an anode; and

an organic light-emitting layer between the electron transfer layer and the hole transfer layer;

the anode on the organic EL layer, the cathode disposed closer to the first substrate than the anode, wherein the anode has a protrusion formed by the step on the cathode;

a second substrate corresponding to the first substrate; and

a driving transistor containing a drain electrode on the second substrate, wherein the drain electrode comes in contact with the anode

to bond the first substrate and the second substrate to each other.