EL display device and manufacturing method thereof

• US 8,198,806 B2
• Filed: 04/12/2010
• Issued: 06/12/2012
• Est. Priority Date: 09/03/1999
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Patel, Ashok
• Application Number:
  US12/758,566
• Publication Number:
  US 20100194275A1
• Time in Patent Office: 792 Days
• Field of Search: None
• US Class Current: 313/506
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1251 comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs
• CPC Class Codes: H01L 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile
• CPC Class Codes: H01L 29/78627 with a significant overlap between the lightly doped drain and the gate electrode, e.g. GOLDD
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 2102/321 Inverted OLED, i.e. having cathode between substrate and anode
• CPC Class Codes: H10K 50/805 Electrodes
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/822 characterised by their shape
• CPC Class Codes: H10K 50/826 Multilayers, e.g. opaque multilayers
• CPC Class Codes: H10K 50/854 comprising scattering means
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/123 Connection of the pixel electrodes to the thin film transistors [TFT]
• CPC Class Codes: H10K 59/17 Passive-matrix OLED displays
• CPC Class Codes: H10K 59/805 Electrodes

Abstract

Reducing the manufacturing cost of an EL display device and an electronic device furnished with the EL display device is taken as an objective. A textured structure in which projecting portions are formed on the surface of a cathode is used. External stray light is diffusely (irregularly) reflected by the action of the projecting portions when reflected by the surface of the cathode, and therefore a defect in which the face of an observer or the surrounding scenery is reflected in the surface of the cathode can be prevented. This can be completed without using a conventionally necessary high price circular polarizing film, and therefore it is possible to reduce the cost of manufacturing the EL display device.

Claims

1. An electroluminescence device comprising:

a first electrode;

a light emitting layer comprising an organic electroluminescent material over the first electrode; and

a second electrode over the light emitting layer,

wherein at least an upper surface of the first electrode has projecting portions, and

wherein a spacing between the projecting portions is in the range of 0.05 to 1 μ

m.

2. An electroluminescence device according to claim 1,

wherein the first electrode is a cathode, and

wherein the second electrode is an anode.

3. An electroluminescence device according to claim 1,

wherein the projection portions are unregulated.

4. An electroluminescence device according to claim 1, further comprising an insulating film comprising a resin material,

wherein the first electrode is formed over the insulating film.

5. An electroluminescence device according to claim 1, further comprising a thin film transistor electrically connected to the first electrode.

6. An electroluminescence device according to claim 1 is a display device.

7. An electroluminescence device comprising:

a first electrode;

a light emitting layer comprising an organic electroluminescent material over the first electrode; and

a second electrode over the light emitting layer,

wherein the light emitting layer has projecting portions, and

wherein a spacing between the projecting portions is in the range of 0.05 to 1 μ

m.

8. An electroluminescence device according to claim 7,

wherein the first electrode is a cathode, and

wherein the second electrode is an anode.

9. An electroluminescence device according to claim 7,

wherein the projection portions are unregulated.

10. An electroluminescence device according to claim 7, further comprising an insulating film comprising a resin material,

wherein the first electrode is formed over the insulating film.

11. An electroluminescence device according to claim 7, further comprising a thin film transistor electrically connected to the first electrode.

12. An electroluminescence device according to claim 7 is a display device.

13. An electroluminescence device comprising:

a first electrode;

a light emitting layer comprising an organic electroluminescent material over the first electrode; and

a second electrode over the light emitting layer,

wherein at least a lower surface of the second electrode has projecting portions, and

wherein a spacing between the projecting portions is in the range of 0.05 to 1 μ

m.

14. An electroluminescence device according to claim 13,

wherein the first electrode is a cathode, and

wherein the second electrode is an anode.

15. An electroluminescence device according to claim 13,

wherein the projection portions are unregulated.

16. An electroluminescence device according to claim 13, further comprising an insulating film comprising a resin material,

wherein the first electrode is formed over the insulating film.

17. An electroluminescence device according to claim 13, further comprising a thin film transistor electrically connected to the first electrode.

18. An electroluminescence device according to claim 13 is a display device.