Light-emitting device and electric apparatus

• US 6,858,878 B2
• Filed: 01/07/2003
• Issued: 02/22/2005
• Est. Priority Date: 05/06/2000
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Koyama, Jun, Yamazaki, Shunpei
• Primary Examiner(s): Flynn, Nathan J.
• Assistant Examiner(s): Forde, Remmon R.
• Application Number:
  US10/337,416
• Publication Number:
  US 20030146446A1
• Time in Patent Office: 777 Days
• Field of Search: 257/98, 257/91, 257/99, 257/744, 257/745, 257/749, 313/503, 313/491, 313/492
• US Class Current: 257/98
• CPC Class Codes: H05B 33/02 Details
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/828 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 50/865 comprising light absorbing layers, e.g. light-blocking layers
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/80524 Transparent cathodes, e.g. comprising thin metal layers
• CPC Class Codes: H10K 59/8792 comprising light absorbing layers, e.g. black layers

Abstract

A light shield film is provided adjacent to an anode of an EL element that consists of the anode, an EL layer, and a cathode. The anode and the cathode are transparent or semitransparent to visible light and hence transmit EL light. With this structure, ambient light is absorbed by the light shield film and does not reach an observer. This prevents an external view from appearing on the observation surface.

Claims

1. A light-emitting device comprising:

an electroluminescence element comprising an anode, a cathode, and an electroluminescence layer between said anode and said cathode, formed over a substrate; and

a light shield film in contact with said electroluminescence element, formed over said substrate,

wherein said cathode comprises a first layer in contact with said electroluminescence layer and a second layer in contact with said first layer, and

wherein said first layer comprises a metal containing a group-1 or group-2 element in the periodic table, and said second layer comprises an oxide conductive film.

2. The light-emitting device according to claim 1, wherein said light shield film is a film selected from the group consisting of an insulating film dispersed with metal particles or carbon particles, a titanium film, a titanium nitride film, a chromium film, a molybdenum film, a tungsten film, a tantalum film, or a tantalum nitride film, and a semiconductor film.

3. The light-emitting device according to claim 1, wherein said anode is an oxide conductive film.

4. The light-emitting device according to claim 1, wherein said first layer is 5-70 nm in thickness.

5. The light-emitting device according to claim 1, wherein at least one thin film transistor formed over said substrate is electrically connected to said anode or said cathode.

6. A camera comprising:

an electroluminescence element comprising an anode, a cathode, and an electroluminescence layer between said anode and said cathode, formed over a substrate; and

a light shield film in contact with said electroluminescence element, formed over said substrate,

wherein said cathode comprises a first layer in contact with said electroluminescence layer and a second layer, and

wherein said first layer comprises a metal containing a group-1 or group-2 element in the periodic table, and said second layer comprises an oxide conductive film.

7. A camera according to claim 6, wherein at least one thin film transistor formed over said substrate is electrically connected to said anode or said cathode.

8. A camera according to claim 6, said light shield film is a film selected from the group consisting of an insulating film dispersed with metal particles or carbon particles, a titanium film, a titanium nitride film, a chromium film, a molybdenum film, a tungsten film, a tantalum film, or a tantalum nitride film, and a semiconductor film.

9. A camera according to claim 6, wherein said first layer is 5-70 nm in thickness.

10. An image reproducing apparatus comprising:

an electroluminescence element comprising an anode, a cathode, and an electroluminescence layer between said anode and said cathode, formed over a substrate; and

a light shield film in contact with said electroluminescence element, formed over said substrate,

wherein said cathode comprises a first layer in contact with said electroluminescence layer and a second layer in contact with said light shield film,

wherein said first layer comprises a metal containing a group-1 or group-2 element in the periodic table, and said second layer comprises an oxide conductive film.

11. An image reproducing apparatus according to claim 10, wherein at least one thin film transistor formed over said substrate is electrically connected to said cathode or said anode.

12. An image reproducing apparatus according to claim 10, said light shield film is a film selected from the group consisting of an insulating film dispersed with metal particles or carbon particles, a titanium film, a titanium nitride film, a chromium film, a molybdenum film, a tungsten film, a tantalum film, or a tantalum nitride film, and a semiconductor film.

13. An image reproducing apparatus according to claim 10, wherein said first layer is 5-70 nm in thickness.

14. A mobile computer comprising:

an electroluminescence element comprising an anode, a cathode, and an electroluminescence layer between said anode and said cathode, formed over a substrate; and

a light shield film in contact with said electroluminescence element, formed over said substrate,

wherein said cathode comprises a first layer in contact with said electroluminescence layer and a second layer in contact with said light shield film, and

wherein said first layer comprises a metal containing a group-1 or group-2 element in the periodic table, and said second layer comprises an oxide conductive film.

15. A mobile computer according to claim 14, wherein at least one thin film transistor formed over said substrate is electrically connected to said anode or said cathode.

16. A mobile computer according to claim 14, said light shield film is a film selected from the group consisting of an insulating film dispersed with metal particles or carbon particles, a titanium film, a titanium nitride film, a chromium film, a molybdenum film, a tungsten film, a tantalum film, or a tantalum nitride film, and a semiconductor film.

17. A mobile computer according to claim 14, wherein said first layer is 5-70 nm in thickness.

18. A mobile computer according to claim 14, wherein said light-emitting device is incorporated into an electronic apparatus selected from the group consisting of an EL display, a video camera, a digital camera, an image reproducing apparatus, a mobile computer, a personal computer, a cellular phone, and a car audio apparatus.

19. A personal computer comprising:

an electroluminescence element comprising an anode, a cathode, and an electroluminescence layer between said anode and said cathode, formed over a substrate; and

a light shield film in contact with said electroluminescence element, formed over said substrate,

wherein said cathode comprises a first layer in contact with said electroluminescence layer and a second layer, and

wherein said first layer comprises a metal containing a group-1 or group-2 element in the periodic table, and said second layer comprises an oxide conductive film.

20. A personal computer according to claim 19, wherein at least one thin film transistor formed over said substrate is electrically connected to said cathode or said anode.

21. A personal computer according to claim 19, said light shield film is a film selected from the group consisting of an insulating film dispersed with metal particles or carbon particles, a titanium film, a titanium nitride film, a chromium film, a molybdenum film, a tungsten film, a tantalum film, or a tantalum nitride film, and a semiconductor film.

22. A personal computer according to claim 19, wherein said first layer is 5-70 nm in thickness.

23. A cellular phone comprising:

an electroluminescence element comprising an anode, a cathode, and an electroluminescence layer between said anode and said cathode, formed over a substrate; and

a light shield film in contact with said electroluminescence element, formed over said substrate,

wherein said cathode comprises a first layer in contact with said electroluminescence layer and a second layer, and

wherein said first layer comprises a metal containing a group-1 or group-2 element in the periodic table, and said second layer comprises an oxide conductive film.

24. A cellular phone according to claim 23, wherein at least one thin film transistor formed over said substrate is electrically connected to said cathode or said anode.

25. A cellular phone according to claim 23, said light shield film is a film selected from the group consisting of an insulating film dispersed with metal particles or carbon particles, a titanium film, a titanium nitride film, a chromium film, a molybdenum film, a tungsten film, a tantalum film, or a tantalum nitride film, and a semiconductor film.

26. A cellular phone according to claim 23, wherein said first layer is 5-70 nm in thickness.

27. A car audio apparatus comprising:

an electroluminescence element comprising an anode, a cathode, and an electroluminescence layer between said anode and said cathode, formed over a substrate; and

a light shield film in contact with said electroluminescence element, formed over said substrate,

wherein said cathode comprises a first layer in contact with said electroluminescence layer and a second layer, and

wherein said first layer comprises a metal containing a group-1 or group-2 element in the periodic table, and said second layer comprises an oxide conductive film.

28. A car audio apparatus according to claim 27, wherein at least one thin film transistor formed over said substrate is electrically connected to said cathode or said anode.

29. A car audio apparatus according to claim 27, said light shield film is a film selected from the group consisting of an insulating film dispersed with metal particles or carbon particles, a titanium film, a titanium nitride film, a chromium film, a molybdenum film, a tungsten film, a tantalum film, or a tantalum nitride film, and a semiconductor film.

30. A car audio apparatus according to claim 27, said first layer is 5-70 nm in thickness.