ORGANIC ELECTROLUMINESCENT DEVICE, LIGHTING APPARATUS, AND METHOD FOR MANUFACTURING THE ORGANIC ELECTROLUMINESCENT DEVICE

• US 20130182418A1
• Filed: 12/12/2012
• Published: 07/18/2013
• Est. Priority Date: 01/17/2012
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Tomoaki Sawabe
• Inventors: SAWABE, Tomoaki, Ono, Tomio, Sugi, Keiji, Enomoto, Shintaro
• Granted Patent: US 8,963,414 B2
• Time in Patent Office: Days
• US Class Current: 362/157
• CPC Class Codes: F21L 4/00 Electric lighting devices with self-contained electric batteries or cells
• CPC Class Codes: H10K 50/80 Constructional details
• CPC Class Codes: H10K 50/814 combined with auxiliary electrodes, e.g. ITO layer combined with metal lines
• CPC Class Codes: H10K 50/822 characterised by their shape
• CPC Class Codes: H10K 50/854 comprising scattering means
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass

Abstract

According to one embodiment, an organic electroluminescent device includes first and second electrodes, an interconnection layer, an organic light emitting layer and a light scattering layer. The first electrode has includes first, second and third portions. The interconnection layer is electrically connected to the first electrode. The third portion overlays the interconnection layer when projected to the plane. The first and second portions do not overlay the interconnection layer. The second electrode overlays the second portion and does not overlay the first and the third portions. The organic light emitting layer is provided between the second portion and the second electrode. The second portion is disposed between the fourth portion of the light scattering layer and the second electrode. The fifth portion of the light scattering layer overlays the interconnection layer. The light scattering layer does not overlay the first portion when projected to the plane.

Claims

1. An organic electroluminescent device comprising:

a first electrode having a major surface and including a first portion, a second portion arranged with the first portion in a first direction parallel to the major surface and a third portion arranged with the first portion in the first direction, the first electrode being light transmissive;

an interconnection layer extending in a plane parallel to the major surface, the interconnection layer being light-reflective and electrically connected to the first electrode, and having a conductivity higher than a conductivity of the first electrode, the third portion overlaying the interconnection layer when projected to the plane, and the first portion and the second portion not overlaying the interconnection layer when projected to the plane;

a second electrode being light-reflective, the second electrode overlaying the second portion and not overlaying the first portion and the third portion when projected to the plane;

an organic light emitting layer provided between the second portion and the second electrode; and

a light scattering layer including a fourth portion and a fifth portion arranged with the fourth portion in a direction parallel to the major surface, the second portion being disposed between the fourth portion and the second electrode, the fifth portion overlaying the interconnection layer when projected to the plane, and the light scattering layer not overlaying the first portion when projected to the plane.

2. The device according to claim 1, further comprising a substrate provided between the first electrode and the light scattering layer, the substrate being light transmissive.

3. The device according to claim 2, further comprising an intermediate layer provided between the substrate and the first electrode and including an irregular structure portion.

4. The device according to claim 1, wherein the second electrode has a width not less than 1 micrometer and not more than 2000 micrometers.

5. The device according to claim 1, wherein

the interconnection layer has a strip-shaped portion extending along a direction parallel to the plane, and

a width of the interconnection layer is not less than 1 micrometer and not more than 2000 micrometers, the width being along the direction perpendicular to the extending direction of the strip-shaped portion of the interconnection layer and parallel to the plane.

6. The device according to claim 1, wherein the interconnection layer includes at least one selected from the group consisting of Mo, Ta, Nb, Al, Ni, and Ti.

7. The device according to claim 1, wherein a width of the first electrode along a direction parallel to the plane is not less than 20 millimeters.

8. The device according to claim 1, wherein a light emitted from the organic light emitting layer is a white light.

9. The device according to claim 1, wherein the second electrode includes a plurality of strip-shaped first pattern portions extending in a first direction parallel to the major surface.

10. The device according to claim 9, wherein the second electrode further including a plurality of strip-shaped second pattern portions extending along a second direction parallel to the major surface and non-parallel to the first direction.

11. The device according to claim 1, wherein the second electrode includes at least one of aluminum and silver.

12. The device according to claim 1, wherein the light scattering layer includes a resin layer and a plurality of particles, the particles being dispersed in the resin layer and having an average diameter not less than 200 nanometers and not more than 100 micrometers.

13. The device according to claim 12, wherein an absolute value of a difference between a refractive index of the resin layer and a refractive index of the particles is not less than 0.1.

14. The device according to claim 1, wherein the light scattering layer changes a travel direction of a light emitted from the organic light emitting layer.

15. The device according to claim 1, wherein the light scattering layer scatters a light reflected by the interconnection layer and the second electrode.

16. The device according to claim 1, wherein the light scattering layer scatters an external light incident upon at least one of the interconnection layer and the second electrode.

17. The device according to claim 1, wherein the second electrode has a grid pattern.

18. A lighting apparatus comprising:

an organic electroluminescent device including

a first electrode having a major surface and including a first portion, a second portion arranged with the first portion in a first direction parallel to the major surface and a third portion arranged with the first portion in the first direction, the first electrode being light transmissive,

an interconnection layer extending in a plane parallel to the major surface, the interconnection layer being light-reflective and electrically connected to the first electrode, and having a conductivity higher than a conductivity of the first electrode, the third portion overlaying the interconnection layer when projected to the plane, and the first portion and the second portion not overlaying the interconnection layer when projected to the plane,

a second electrode being light-reflective, the second electrode overlaying the second portion and not overlaying the first portion and the third portion when projected to the plane,

an organic light emitting layer provided between the second portion and the second electrode, and

a light scattering layer including a fourth portion and a fifth portion arranged with the fourth portion in a direction parallel to the major surface, the second portion being disposed between the fourth portion and the second electrode, the fifth portion overlaying the interconnection layer when projected to the plane, and the light scattering layer not overlaying the first portion when projected to the plane; and

a power supply unit electrically connected to the interconnection layer and the second electrode, and configured to supply a current passing through the organic light emitting layer via the interconnection layer, the first electrode, and the second electrode.

19. A method for manufacturing an organic electroluminescent device comprising:

preparing a workpiece including;

a first electrode having a major surface and including a first portion, a second portion arranged with the first portion in a first direction parallel to the major surface and third portion arranged with the first portion in the first direction, the first electrode being light transmissive;

an interconnection layer extending in a plane parallel to the major surface, the interconnection layer being light-reflective and electrically connected to the first electrode, and having a conductivity higher than a conductivity of the first electrode, the third portion overlaying the interconnection layer when projected to the plane and the first portion and the second portion not overlaying the interconnection layer when projected to the plane;

a second electrode being light-reflective, the second electrode overlaying the second portion and not overlaying the first portion and the third portion when projected to the plane;

an organic light emitting layer provided between the second portion and the second electrode; and

a light scattering layer including a fourth portion and a fifth portion arranged with the fourth portion in a direction parallel to the major surface, the second portion being disposed between the fourth portion and the second electrode, the fifth portion overlaying the interconnection layer when projected to the plane, and the light scattering layer not overlaying the first portion when projected to the plane, the work piece having a processing surface parallel to the plane; and

forming a light scattering layer on the processing surface by exposure processing using the interconnection layer and the second electrode as masks, the light scattering layer including a fourth portion and a fifth portion arranged with the fourth portion in a direction parallel to the major surface, the second portion being disposed between the fourth portion and the second electrode, the fifth portion overlaying the interconnection layer when projected to the plane, and the light scattering layer not overlaying the first portion when projected to the plane.

20. The method according to claim 19, wherein

the forming the light scattering layer includes

forming a resin film on the processing surface, the resin film capable to generate a photosensitivity, and

irradiating the resin film with a light to cause the photosensitivity to be generated by using the interconnection layer and the second electrode as masks to process the resin film into a pattern reflecting pattern shapes of the interconnection layer and the second electrode.