Organic EL device with high contrast ratio and method for manufacturing the same

• US 6,781,293 B2
• Filed: 10/05/2001
• Issued: 08/24/2004
• Est. Priority Date: 10/14/2000
• Status: Expired due to Fees

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung SDI Company Limited
• Inventors: Cho, Sung-Woo
• Primary Examiner(s): Leurig, Sharlene L
• Application Number:
  US09/970,993
• Publication Number:
  US 20020043928A1
• Time in Patent Office: 1,054 Days
• Field of Search: 313/311, 313/498, 313/503, 313/505, 313/506, 315/169.3, 427/66
• US Class Current: 313/311
• CPC Class Codes: H10K 50/826 Multilayers, e.g. opaque multilayers
• CPC Class Codes: H10K 50/865 comprising light absorbing layers, e.g. light-blocking layers
• CPC Class Codes: H10K 59/173 comprising banks or shadow masks

Abstract

The present invention discloses an organic EL device, including: a transparent substrate having a display region and a non-display region, the display region having a pixel region; first electrodes formed on the display region of the substrate and spaced apart from each other; EL light-emitting layers formed on the portions of the first electrode corresponding to the pixel region; and second electrodes formed over the display region and having a light absorbing layer interposed therein.

Claims

1. An organic EL device, comprising:

a transparent substrate having a display region and a non-display region, the display region having a pixel region;

first electrodes formed on the display region of the substrate and spaced apart from each other;

EL light-emitting layers formed on portions of the first electrode corresponding to the pixel region; and

second electrodes formed over the EL light-emitting layers and comprising a first layer, a second layer and a light absorbing layer interposed between the first layer and the second layer.

2. The device of claim 1, wherein the first layer is adjacent to the EL light-emitting layer and thin enough to transmit part of ambient light.

3. The device of claim 2, wherein the first layer is less than about 100 Å

thick.

4. The device of claim 2, wherein the second electrode is thicker than the first electrode.

5. The device of claim 1, wherein the light absorbing layer of the second electrode is disposed on a location corresponding to the pixel region.

6. The device of claim 1, wherein the light absorbing layer is made of a material absorbing ambient light.

7. The device of claim 6, wherein the light absorbing layer is made of carbon, an inorganic material or an organic material.

8. The device of claim 1, further comprising cathode leads formed on the non-display region of the substrate and electrically connected to the second electrode.

9. The device of claim 8, further comprising an interlayer insulator formed on the substrate between said first electrodes, wherein the interlayer insulator includes a contact hole, and the cathode leads are electrically connected to the second electrode through the contact hole.

10. The device of claim 1, wherein the first electrode is made of indium tin oxide (ITO).

11. The device of claim 1, wherein the second electrode is made of low work function metal such as Al, Li, In, Mg, Ag, Ca or Ba.

12. The device of claim 1, further comprising:

an interlayer insulator formed over a portion of the display region except for portions of the first electrode corresponding to the pixel region; and

partition walls formed on the interlayer insulator in a perpendicular direction to the first electrodes.

13. A method for manufacturing an organic EL device, comprising:

a) forming first electrodes spared apart from each other on a transparent substrate having a display region with a pixel region and a non-display region;

b) forming an EL light-emitting layer on the portions of the first electrode corresponding to the pixel region; and

c) forming second electrodes with a light absorbing layer therein over the display region.

14. The method of claim 13, wherein the step of forming second electrodes further comprising steps of:

forming a first layer on the EL light-emitting layer;

forming the light absorbing layer on the first layer; and

forming a second layer on the light absorbing layer.

15. The method of claim 13, wherein the first layer is thin enough to transmit part of ambient light.

16. The method of claim 15, wherein the first layer of the second electrode is less than about 100 Å

thick.

17. The method of claim 15, wherein the second electrode is thicker than the first electrode.

18. The method of claim 13, wherein the light absorbing layer of the second electrode is disposed on a location corresponding to the pixel region except for the cathode contact hole region.

19. The method of claim 13, wherein the light absorbing layer is made of a material absorbing ambient light.

20. The method of claim 19, wherein the light absorbing layer is made of carbon, an inorganic material or an organic material.

21. The method of claim 20, further comprising, after the step of (a), the steps of:

forming an interlayer insulator over a portion of the display region except for portions of the first electrode corresponding to the pixel region; and

forming partition walls on the interlayer insulator in a direction perpendicular to the first electrodes.