Self light-emitting device using an inert gas

• US 6,847,163 B1
• Filed: 10/25/2000
• Issued: 01/25/2005
• Est. Priority Date: 10/29/1999
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Konuma, Toshimitsu, Mizukami, Mayumi, Tsutsui, Tetsuo
• Primary Examiner(s): Patel, Nimeshkumar D.
• Assistant Examiner(s): COLON, GERMAN
• Application Number:
  US09/696,619
• Time in Patent Office: 1,553 Days
• Field of Search: 313498-512, 313483-484
• US Class Current: 313/512
• CPC Class Codes: G02F 1/133602 Direct backlight
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 2102/351 Thickness
• CPC Class Codes: H10K 50/8428 Vertical spacers, e.g. arranged between the sealing arrangement and the OLED
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/17 Passive-matrix OLED displays

Abstract

To provide a method of improving an efficiency for extracting light in a self light-emitting device using an organic EL material. In the self light-emitting device having a structure in which an EL layer (102) is sandwiched between a transparent electrode (103) and a catrode (101), a film thickness of the EL layer (102) and a film thickness of the transparent electrode (102) are equivalent to the film thicknesses in which there is no occurrence of a guided light, and an inert gas is filled in a space between the transparent electrode (103) and a cover material (105).

Claims

1. A self light-emitting device comprising:

an opaque electrode over a substrate;

an EL layer over the opaque electrode;

a transparent electrode over the EL layer; and

an inert gas filled in a space between the transparent electrode and a cover material, wherein each of said EL layer and said transparent electrode has a film thickness (d) in which there is substantially no occurrence of a guided light in terms of a wavelength of a light generated in said EL layer, and

wherein said light generated in said EL layer is emitted to said cover material side.

2. A device according to claim 1, wherein said film thickness (d) satisfies a formula d≦

λ

/(4n), when a light with a wavelength generated by the EL layer passes through a medium with a refractive index n.

3. A self light-emitting device comprising:

an opaque electrode over a substrate;

an EL layer over the opaque electrode, said EL layer having a light-emitting layer;

a transparent electrode over the EL layer;

an inert gas is filled in a space between the transparent electrode and a cover material; and

a buffer layer provided between said light-emitting layer and said transparent electrode or between said light-emitting layer and said opaque electrode,

wherein each of said EL layer and said transparent electrode has a film thickness (d) in which there is substantially no occurrence of a guided light in terms of a wavelength of a light generated in said EL layer, and

wherein said light generated in said EL layer is emitted to said cover material side.

4. A device according to claim 3, wherein said film thickness (d) satisfies a formula d≦

λ

/(4n), when a light with a wavelength generated by the EL layer passes through a medium with a refractive index n.

5. A self light-emitting device having a pixel portion comprising a semiconductor device and an EL element electrically connected to the semiconductor device formed on a substrate, said EL element comprising:

an opaque electrode;

an EL layer over the opaque electrode;

a transparent electrode over the EL layer; and

an inert gas filled in a space between the transparent electrode and a cover material,

wherein each of said EL layer and said transparent electrode has a film thickness (d) in which there is substantially no occurrence of a guided light in terms of a wavelength of a light generated in said EL layer, and

wherein said light generated in said EL layer is emitted to said cover material side.

6. A device according to claim 5, wherein said film thickness (d) satisfies a formula d≦

λ

/(4n), when a light with a wavelength generated by the EL layer passes through a medium with a refractive index n.

7. A self light-emitting device having a pixel portion comprising a semiconductor device and an EL element electrically connected to the semiconductor device formed on a substrate, said EL element comprising:

an opaque electrode;

an EL layer over the opaque electrode, said EL layer having a light-emitting layer;

a transparent electrode over the EL layer;

an inert gas filled in a space between the transparent electrode and a cover material; and

a buffer layer provided between said light-emitting layer and said transparent electrode or between said light-emitting layer and said opaque electrode,

wherein each of said EL layer and said transparent electrode has a film thickness (d) in which there is substantially no occurrence of a guided light in terms of a wavelength of a light generated in said EL layer, and

wherein said light generated in said EL layer is emitted to said cover material side.

8. A device according to claim 7, wherein said film thickness (d) satisfies a formula d≦

λ

/(4n), when a light with a wavelength generated by the EL layer passes through a medium with a refractive index n.

9. A self light-emitting device having a pixel portion comprising:

a plurality of opaque electrodes arranged in stripe shapes over a substrate;

an EL layer over the plurality of opaque electrodes;

a plurality of transparent electrodes over the EL layer, the plurality of transparent electrodes provided in stripe shapes so as to be orthogonal to the plurality of opaque electrodes; and

an inert gas filled in a space between the transparent electrode and a cover material,

wherein each of said EL layer and said transparent electrode has a film thickness (d) in which there is substantially no occurrence of a guided light in terms of a wavelength of a light generated in said EL layer, and

wherein a said light generated in said EL layer is emitted to said cover material side.

10. A device according to claim 9, wherein said film thickness (d) satisfies a formula d≦

λ

/(4n), when a light with a wavelength generated by the EL layer passes through a medium with a refractive index n.

11. A self light-emitting device having a pixel portion comprising:

a plurality of opaque electrodes arranged in stripe shapes over a substrate;

an EL layer over the plurality of opaque electrodes;

a plurality of transparent electrodes over the EL layer, the plurality of the transparent electrodes provided in stripe shapes so as to be orthogonal to the plurality of opaque electrodes; and

an inert gas filled in a space between the transparent electrode and a cover material; and

a buffer layer provided between said EL layer and said transparent electrode or between said EL layer and said transparent electrode has a film thickness (d) in which there is substantially no occurrence of a guided light in terms of a wavelength of a light generated in said EL layer, and

wherein said light generated in said EL layer is emitted to said cover material side.

12. A device according to claim 11, wherein said film thickness (d) satisfies a formula d≦

λ

/(4n), with a wavelength generated by the EL layer passes through a medium with a refractive index n.