WO2014103042A1

WO2014103042A1 - Light-emitting device

Info

Publication number: WO2014103042A1
Application number: PCT/JP2012/084166
Authority: WO
Inventors: 黒田　和男
Original assignee: パイオニア株式会社
Priority date: 2012-12-28
Filing date: 2012-12-28
Publication date: 2014-07-03

Abstract

This light-emitting device is provided with an organic functional layer (50) and a translucent layer (100). The translucent layer (100) has an interface (35) and an interface (36). The interface (35) comprises alternately arranged first inclined surfaces (35a) and second inclined surfaces (35b), and a first light reflecting film (25) is formed along the second inclined surfaces (35b). The interface (36) comprises multiple protrusions (70). Each of the protrusions (70) includes three or more inclined surfaces inclined relative to the organic functional layer (50) in mutually different directions, and at least one of these inclined surfaces is not perpendicular to the organic functional layer (50).

Description

Light emitting device

The present invention relates to a light emitting device having an organic light emitting layer.

There is a light emitting device having an organic light emitting layer as one of the light emitting devices. In this light emitting device, it is desired to improve the ratio of light emitted to the outside (light extraction efficiency) of the light generated in the organic light emitting layer.

As a technique for improving the light extraction efficiency, there is a technique described in Patent Document 1. A surface light source device described in Patent Document 1 includes a light extraction substrate that constitutes a light emission surface of a light emitting element, a transparent resin layer provided on the light emission surface side of the substrate, and a light emission surface of the transparent resin layer. And a high refractive index thin film provided on the side surface. The transparent resin layer has a pyramid-shaped or prism-shaped concavo-convex structure on its light-emitting surface side. The angle formed between the pyramid-shaped or prism-shaped slope and the light exit surface is more than 40 ° and less than 65 °. The high refractive index thin film is provided along the concavo-convex structure, and the film thickness at each location is within an average film thickness ± 30%. The refractive index of the high refractive index thin film is higher than the refractive index of the transparent resin layer. 15-30% higher.

Further, Patent Document 2 describes a technique for taking out light confined in the light emitting layer by total reflection to the outside of the light emitting layer by arranging the reflector obliquely on the side of the light emitting layer.

Further, in the technique of Patent Document 3, the portion facing the light emission space in the light emitting device is constituted by two faces of a triangular prism shape. These two surfaces are alternately arranged in the x direction parallel to the light emitting layer, extend in the y direction parallel to the light emitting layer and orthogonal to the x direction, and Is inclined. One of these two surfaces is light reflective.

JP 2009-146654 A JP-T-2001-507503 Special table 2011-507164

Light extraction efficiency is reduced in an organic EL (Electro Luminescence) light emitting device configured by laminating a light transmitting electrode, an organic functional layer including a light emitting layer, and a metal electrode on a light transmitting substrate such as a glass substrate. There are the following three factors. (1) Due to the difference in refractive index between the translucent substrate and the translucent electrode, total reflection occurs at these interfaces, and light generated in the light emitting layer does not enter the translucent substrate. (2) Due to the difference in refractive index between the translucent substrate and the light emission space (air), total reflection occurs at these interfaces, and the light generated in the light emitting layer is not emitted to the outside. (3) The light transmitted through each layer is attenuated according to the light transmittance of each layer constituting the organic EL light emitting device. In particular, the light incident in an oblique direction with respect to the light-transmitting electrode having a relatively low light transmittance has a significant attenuation because the optical path length becomes long.

FIG. 1 is a diagram schematically showing the direction in which light is emitted from the light emitting point of the light emitting layer. Light is emitted in all directions (spherically) from the light emitting point of the light emitting layer. Note that FIG. 1 shows a state in which light is emitted in a hemispherical form from the light emitting point P1 in order to make the drawing easy to see. In the present general light emitting device, only light having an angle of about 20 degrees or less (light in the circular region R101 shown in FIG. 1) can be extracted from the light emitting device with reference to a line perpendicular to the translucent electrode. Absent. However, the region having a larger angle with the line perpendicular to the translucent electrode (for example, the annular region R102 shown in FIG. 1) has a larger total amount of light emitted from the light emitting point P1. This is because the area of the region R102 is larger than that of the region R101 shown in FIG. For this reason, the angle of the light extracted from the light emitting device is more than the angle that is within about 20 degrees with respect to a line perpendicular to the translucent electrode, for example, improved by 5 degrees to about 25 degrees. The improvement effect of the light extraction efficiency is larger when the extraction efficiency of light having a large current (for example, light in the region R102 shown in FIG. 1) is improved by 5 degrees.

In the technique of Patent Document 1, the total reflection occurring at the interface between the translucent substrate and the light emission space (air) is suppressed to improve the light extraction efficiency, and the above factor (2) is to be eliminated. Admitted to do. However, even if the above factor (2) is eliminated, unless the total reflection generated at the interface between the translucent electrode and the translucent substrate is efficiently suppressed (that is, the above factor (1) is efficiently eliminated). Unless it is) light extraction efficiency cannot be increased dramatically. That is, even in the structure described in Patent Document 1 described above, there is a lot of light that cannot be extracted to the outside, and it is considered that further improvement in light extraction efficiency is required.

The thickness of the light emitting layer of the organic EL light emitting device is very thin. For this reason, in the technique of Patent Document 2, unless the light emitting layers and the reflectors are alternately arranged at short intervals in the surface direction of the light emitting layer, light is attenuated by repeated reflection in the light emitting layer. For this reason, since the area which can arrange | position a light emitting layer becomes small compared with the area of a light-emitting device, the light emission efficiency in the whole light-emitting device is bad.

In the technique of Patent Document 3, light having no directional component in the x direction out of light having a directional component in the y direction that is greater than or equal to the critical angle is totally reflected by the two surfaces and is not extracted into the light emission space. There is room for improvement in light extraction efficiency.

An example of a problem to be solved by the present invention is to improve the light extraction efficiency of the light emitting device.

The invention according to claim 1 includes an organic functional layer including a light emitting layer,
A translucent layer disposed on one side of the organic functional layer;
With
The surface opposite to the organic functional layer in the translucent layer constitutes a light extraction surface that emits light emitted by the light emitting layer,
The translucent layer is
In order from the side closer to the organic functional layer,
A first light transmissive layer;
A second light transmissive layer having an interface with the first light transmissive layer;
Have
The interface between the first light transmissive layer and the second light transmissive layer is a first inclined surface that is inclined with respect to the organic functional layer, and an inclination direction of the first inclined surface with respect to the organic functional layer A second inclined surface inclined in the opposite direction to
A plurality of the first inclined surfaces and a plurality of the second inclined surfaces are arranged in the first direction parallel to the organic functional layer such that the first inclined surfaces and the second inclined surfaces are alternately positioned. Arranged side by side in one direction,
An interface between the second light transmissive layer and an adjacent region that is a region adjacent to the second light transmissive layer opposite to the first light transmissive layer includes a plurality of protrusions;
A first light reflecting film is formed along at least one of the plurality of first inclined surfaces and the plurality of second inclined surfaces;
Each of the plurality of protrusions includes three or more inclined surfaces inclined in different directions with respect to the organic functional layer, and at least one of these inclined surfaces is defined with respect to the organic functional layer. The light emitting device is not orthogonal.

The invention according to claim 9 includes an organic functional layer including a light emitting layer,
A translucent layer disposed on one side of the organic functional layer;
With
The surface opposite to the organic functional layer in the translucent layer constitutes a light extraction surface that emits light emitted by the light emitting layer,
The translucent layer is
In order from the side closer to the organic functional layer,
A first light transmissive layer;
A second light transmissive layer having an interface with the first light transmissive layer;
Have
The interface between the first light transmissive layer and the second light transmissive layer is a first inclined surface that is inclined with respect to the organic functional layer, and an inclination direction of the first inclined surface with respect to the organic functional layer A second inclined surface inclined in the opposite direction to
A plurality of the first inclined surfaces and a plurality of the second inclined surfaces are arranged in the first direction parallel to the organic functional layer such that the first inclined surfaces and the second inclined surfaces are alternately positioned. Arranged side by side in one direction,
An interface between the second light transmissive layer and an adjacent region that is a region adjacent to the second light transmissive layer opposite to the first light transmissive layer includes a plurality of protrusions;
A first light reflecting film is formed along at least one of the plurality of first inclined surfaces and the plurality of second inclined surfaces;
Each of the plurality of protrusions is a light emitting device formed in a polygonal pyramid shape, a conical shape, a polygonal frustum shape, a truncated cone shape, or a hemispherical shape.

The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.

It is a figure which shows typically the direction in which light is radiated | emitted from the light emission point of a light emitting layer. 2A is a perspective view of the light-emitting device according to the embodiment, FIG. 2B is a cross-sectional view of the light-emitting device according to the embodiment when viewed in the direction of arrow A in FIG. 2A, and FIG. It is sectional drawing which looked at the light-emitting device which concerns on embodiment in the arrow B direction of Fig.2 (a). FIG. 3A is a perspective view of the second light transmissive layer, and FIG. 3B is a perspective view of the first light transmissive layer. FIG. 4A to FIG. 4C are cross-sectional views illustrating paths until light generated in the organic functional layer is emitted to the outside in the light emitting device according to the embodiment. FIG. 5A to FIG. 5C are cross-sectional views illustrating paths until light generated in the organic functional layer is emitted to the outside in the light emitting device according to the embodiment. FIG. 6A to FIG. 6C are cross-sectional views illustrating paths through which light generated in the organic functional layer is emitted to the outside in the light emitting device according to the comparative example. FIG. 7A to FIG. 7C are cross-sectional views illustrating paths until light generated in the organic functional layer is emitted to the outside in the light emitting device according to the comparative example. It is sectional drawing which shows the 1st example of the layer structure of an organic functional layer. It is sectional drawing which shows the 2nd example of the layer structure of an organic functional layer. 10A is a plan view of the light-emitting device according to Example 1, and FIG. 10B is a cross-sectional view taken along the line CC in FIG. 10A. FIG. 11A and FIG. 11B are cross-sectional views of the light emitting device according to the second embodiment. 12A is a cross-sectional view illustrating a part of the light-emitting device according to the third embodiment, and FIG. 12B is a cross-sectional view illustrating a part of the light-emitting device according to the fourth embodiment. 13A is a cross-sectional view showing a part of the light emitting device according to Example 5, FIG. 13B is a plan view showing a part of the first light-transmitting layer in Example 5, and FIG. 13C is the example. FIG. 5 is a perspective view showing a part of a first light transmissive layer in FIG. 10 is a cross-sectional view showing a part of a light emitting device according to Example 6. FIG. FIG. 10 is a cross-sectional view illustrating a part of the light emitting device according to Example 7. FIG. 16A to FIG. 16E are cross-sectional views illustrating a method for manufacturing a light emitting device according to Example 7. FIG. 10 is a cross-sectional view illustrating a part of the light emitting device according to Example 8. FIG. 10 is a cross-sectional view illustrating a part of the light emitting device according to Example 9; FIG. 19A to FIG. 19D are cross-sectional views illustrating a method for manufacturing a light-emitting device according to Example 9. 20A to 20D are cross-sectional views illustrating the method for manufacturing the light emitting device according to the tenth embodiment. 12 is a sectional view of a light emitting device according to Example 11. FIG. It is sectional drawing of the light-emitting device based on Example 12. It is sectional drawing of the light-emitting device based on Example 13. It is a perspective view of the light-emitting device concerning Example 14. 25A is a cross-sectional view of the light-emitting device according to Example 14 as viewed in the direction of arrow A in FIG. 24, and FIG. 25B is a cross-sectional view of the light-emitting device according to Example 14 as viewed in the direction of arrow B of FIG. FIG. It is a top view of the light-emitting device concerning Example 14. FIG. 27A is a perspective view of the light emitting device according to the fifteenth embodiment, and FIG. 27B is a cross-sectional view of the light emitting device according to the fifteenth embodiment when viewed in the direction of arrow A in FIG.

Hereinafter, embodiments will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

(Embodiment)
The light emitting device according to this embodiment includes an organic EL element. This light emitting device can be used as a light source of a display, a lighting device, or an optical communication device, for example.

2A is a perspective view of the light-emitting device according to the embodiment, FIG. 2B is a cross-sectional view of the light-emitting device according to the embodiment when viewed in the direction of arrow A in FIG. 2A, and FIG. It is sectional drawing which looked at the light-emitting device which concerns on embodiment in the arrow B direction of Fig.2 (a).

The light-emitting device according to this embodiment includes an organic functional layer 50 including a light-emitting layer, and a light-transmitting layer 100 disposed on one surface side of the organic functional layer 50. The surface of the translucent layer 100 opposite to the organic functional layer 50 constitutes a light extraction surface d that emits light emitted from the light emitting layer. The light transmissive layer 100 includes a first light transmissive layer 110 and a second light transmissive layer 120 having an interface 35 between the first light transmissive layer 110 in order from the side closer to the organic functional layer 50. The interface 35 between the first light transmitting layer 110 and the second light transmitting layer 120 includes a first inclined surface 35 a that is inclined with respect to the organic functional layer 50 and a first inclined surface 35 a that is inclined with respect to the organic functional layer 50. And a second inclined surface 35b inclined in a direction opposite to the inclined direction. The plurality of first inclined surfaces 35a and the plurality of second inclined surfaces are arranged such that the first inclined surfaces 35a and the second inclined surfaces 35b are alternately positioned in the first direction (arrow B direction) parallel to the organic functional layer 50. 35b are arranged side by side in the first direction. An interface 36 between the second light-transmitting layer 120 and the adjacent region 200 that is adjacent to the second light-transmitting layer 120 on the opposite side of the first light-transmitting layer 110 has a plurality of protrusions 70. The first light reflection film 25 is formed along at least one of the plurality of first inclined surfaces 35a and the plurality of second inclined surfaces 35b. Each of the plurality of protrusions 70 includes three or more inclined surfaces inclined in different directions with respect to the organic functional layer 50, and at least one of these inclined surfaces is relative to the organic functional layer 50. Are not orthogonal. Here, being inclined with respect to the organic functional layer 50 means being inclined with respect to the surface on which the organic functional layer 50 extends, for example, with respect to the upper surface of the organic functional layer 50. Means that Moreover, each protrusion 70 is formed in the shape which diameter-reduces toward the opposite side to the organic functional layer 50 side on the basis of the 1st translucent layer 110, for example. Further, the base end of each projection 70 (the bottom surface of each projection 70 when each projection 70 is regarded as an independent structure) is located on the same plane, for example. For example, the protrusion 70 may have a quadrangular pyramid shape with a vertex shifted from the center in plan view, and one or two side surfaces thereof may be orthogonal to the organic functional layer 50. Further, the protrusion 70 may have a triangular prism shape (laterally triangular prism shape), and one side surface and two bottom surfaces may be orthogonal to the organic functional layer 50. Each of the plurality of protrusions 70 includes three or more inclined surfaces inclined in different directions with respect to the organic functional layer 50, and any of these inclined surfaces is orthogonal to the organic functional layer 50. It is also preferred not to.

Further, the light emitting device according to the present embodiment includes an organic functional layer 50 including a light emitting layer, and a light transmissive layer 100 disposed on one surface side of the organic functional layer 50. The surface of the translucent layer 100 opposite to the organic functional layer 50 constitutes a light extraction surface d that emits light emitted from the light emitting layer. The light transmissive layer 100 includes a first light transmissive layer 110 and a second light transmissive layer 120 having an interface 35 between the first light transmissive layer 110 in order from the side closer to the organic functional layer 50. The interface 35 between the first light transmitting layer 110 and the second light transmitting layer 120 includes a first inclined surface 35 a that is inclined with respect to the organic functional layer 50 and a first inclined surface 35 a that is inclined with respect to the organic functional layer 50. And a second inclined surface 35b inclined in a direction opposite to the inclined direction. The plurality of first inclined surfaces 35a and the plurality of second inclined surfaces are arranged such that the first inclined surfaces 35a and the second inclined surfaces 35b are alternately positioned in the first direction (arrow B direction) parallel to the organic functional layer 50. 35b are arranged side by side in the first direction. An interface 36 between the second light-transmitting layer 120 and the adjacent region 200 that is adjacent to the second light-transmitting layer 120 on the opposite side of the first light-transmitting layer 110 has a plurality of protrusions 70. The first light reflection film 25 is formed along at least one of the plurality of first inclined surfaces 35a and the plurality of second inclined surfaces 35b. Each of the plurality of protrusions 70 is formed in a polygonal pyramid shape, a conical shape, a polygonal frustum shape, a truncated cone shape, or a hemispherical shape. For example, each protrusion 70 is arranged in a direction to reduce the diameter toward the side opposite to the organic functional layer 50 side with respect to the first light transmitting layer 110. Further, the base end of each projection 70 (the bottom surface of each projection 70 when each projection 70 is regarded as an independent structure) is located on the same plane, for example.

Note that at least one of the first inclined surface 35a and the second inclined surface 35b adjacent to each other is not formed with a light reflecting film, and is a light transmitting surface.

In the following, in order to simplify the description, the positional relationship (vertical relationship, etc.) of each component of the light emitting device will be described as the relationship shown in each drawing. However, the positional relationship in this description is irrelevant to the positional relationship when the light emitting device is used.

In the case of this embodiment, the adjacent region 200 is, for example, a light emission space outside the light emitting device. Therefore, in the present embodiment, the adjacent region 200 is composed of an air layer (refractive index 1). That is, the adjacent region 200 is made of gas. Further, for example, the upper surface of the second light transmitting layer 120 is in contact with the air layer and constitutes a light extraction surface d. In addition, the light extraction film is affixed on the upper surface of the 2nd translucent layer 120, and the upper surface of this light extraction film may comprise the light extraction surface d.

The light emitting device further includes a translucent first electrode (translucent electrode) 40 disposed between the organic functional layer 50 and the first translucent layer 110, and the first electrode based on the organic functional layer 50. 40 and a second electrode 60 disposed on the opposite side of 40.

For example, the first electrode 40 is in contact with the surface of the first light transmitting layer 110 on the organic functional layer 50 side. The first electrode 40 may be a transparent electrode made of a metal oxide conductor such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide). However, the first electrode 40 may be a metal thin film that is thin enough to transmit light.

The second electrode 60 is a reflective electrode made of a metal film such as Al. The second electrode 60 reflects light traveling from the organic functional layer 50 toward the second electrode 60 toward the light extraction surface d.

When a voltage is applied between the first electrode 40 and the second electrode 60, the light emitting layer of the organic functional layer 50 emits light. The light-transmitting layer 100 (in the case of the present embodiment, the first light-transmitting layer 110 and the second light-transmitting layer 120), the first electrode 40, and the organic functional layer 50 are all the light-emitting layers of the organic functional layer 50. Transmits at least part of the emitted light. Part of the light emitted from the light emitting layer is emitted (extracted) from the light extraction surface d of the light transmitting layer 100 to the outside of the light emitting device (that is, the light emission space).

3A is a perspective view of the second light transmitting layer 120, and FIG. 3B is a perspective view of the first light transmitting layer 110. FIG.

As shown in FIG. 3A, the second light transmissive layer 120 is a light transmissive plate. A first inclined surface 35 a and a second inclined surface 35 b are formed on the surface of the second light transmitting layer 120 on the first light transmitting layer 110 side, that is, the lower surface 122, and the surface of the second light transmitting layer 120 on the adjacent region 200 side, A plurality of protrusions 70 are formed on the upper surface 121.

As shown in FIG. 3B, the first light transmissive layer 110 is a light transmissive plate. The top surface 111 of the first light transmissive layer 110 is formed in a concavo-convex shape that meshes with the concavo-convex shape of the bottom surface 122 of the second light transmissive layer 120. The interface between the upper surface 111 and the lower surface 122 is the interface 35. The lower surface 112 of the first light transmissive layer 110 is formed flat. However, a certain degree of surface roughness of the lower surface 112 is allowed. The lower surface 112 is disposed in parallel to the organic functional layer 50.

As shown in FIG. 3A, the upper surface 121 of the second light transmitting layer 120 forms an interface 36. For example, a plurality of protrusions 70 can be formed on the upper surface 121 by forming irregularities on the upper surface 121 of the second light transmitting layer 120. The unevenness can be formed by processing the surface of the second light transmitting layer 120 using a known surface processing technique such as cutting and polishing, laser processing, chemical etching, or thermal imprinting. However, the 2nd light transmission layer 120 may be comprised by attaching the several protrusion 70 formed separately on the upper surface of the main body of the 2nd light transmission layer 120 formed flat. Or the 2nd light transmission layer 120 may be comprised by affixing the sheet | seat which has several protrusion 70 on the upper surface of the main body of the 2nd light transmission layer 120 formed flat.

The plurality of protrusions 70 are two-dimensionally distributed on the upper surface of the first light transmissive layer 110. Specifically, for example, the plurality of protrusions 70 are arranged at regular intervals in a matrix or zigzag arrangement in plan view. However, the interval between the adjacent protrusions 70 may not be constant.

It can be mentioned that the plurality of protrusions 70 include protrusions 70 formed in a cone shape. More specifically, each of the plurality of protrusions 70 may be formed in a conical shape, for example.

Alternatively, the plurality of protrusions 70 may include protrusions 70 formed in a polygonal pyramid shape. More specifically, each of the plurality of protrusions 70 may be formed in a polygonal pyramid shape, for example.

More specifically, each of the plurality of protrusions 70 may be formed in a quadrangular pyramid shape, for example. In this case, each of the plurality of protrusions 70 includes four inclined surfaces inclined in different directions with respect to the organic functional layer 50, and none of these inclined surfaces is orthogonal to the organic functional layer 50. . In this case, for example, the plurality of protrusions 70 can be arranged in a matrix in a plan view without any gap. One or two side surfaces of the quadrangular pyramid-shaped protrusion 70 may be orthogonal to the organic functional layer 50.
Further, the shape of the protrusion 70 may be other polygonal pyramid shapes such as a triangular pyramid shape, a pentagonal pyramid shape, and a hexagonal pyramid shape, for example.

Further, the plurality of protrusions 70 may include a protrusion 70 formed in a conical shape. In this case, each of the plurality of protrusions 70 may be formed in a conical shape.

Alternatively, the plurality of protrusions 70 may include a hemispherical protrusion 70. In this case, each of the plurality of protrusions 70 may be formed in a hemispherical shape.

Further, the shape of the protrusion 70 may be a polygonal frustum shape, a truncated cone shape, or a shape in which the top of the hemisphere is cut. Furthermore, the shape of the protrusion 70 is not limited to these shapes, and includes three or more inclined surfaces inclined in different directions with respect to the organic functional layer 50, and at least one of these inclined surfaces. Any shape may be used as long as it satisfies the condition that it is not orthogonal to the organic functional layer 50.

The lower surface 122 of the second translucent layer 120 forming the interface 35 is formed in an uneven shape having a first inclined surface 35a and a second inclined surface 35b. For example, a plurality of first inclined surfaces 35 a and a plurality of second inclined surfaces 35 b are formed by forming a plurality of inverted V grooves parallel to each other on the lower surface of the second light transmitting layer 120. The uneven shape can be formed by processing the surface of the second light transmitting layer 120 using a known surface processing technique such as cutting and polishing, laser processing, chemical etching, or thermal imprinting. However, a plurality of first inclined surfaces 35a and a plurality of second inclined surfaces 35b are formed by attaching a plurality of protrusions in parallel to the lower surface of the main body portion of the second light transmitting layer 120 formed flat. May be. For example, along the first direction (arrow B direction) parallel to the organic functional layer 50, the first inclined surface 35a and the second inclined surface 35b are alternately arranged with no gap. For this reason, the gable roof-shaped protrusion which protrudes toward the 1st translucent layer 110 side is formed of the 1st inclined surface 35a and the 2nd inclined surface 35b which were mutually arrange | positioned mutually.

More specifically, for example, the first inclined surface 35 a has a rectangular surface parallel to the organic functional layer 50, and the first rotation direction about the first rotation axis parallel to the organic functional layer 50. The surface is rotated by a first angle. The second inclined surface 35b located next to the first inclined surface 35a is a rectangular surface parallel to the organic functional layer 50 and is opposite to the first rotation direction around the first rotation axis. It is a surface rotated by a second angle in the second rotation direction of the direction. For example, the first rotation axis is orthogonal to the first direction. In addition, the inclination angles (first angles) of the first inclined surfaces 35a with respect to the organic functional layer 50 are equal to each other, for example. Similarly, the inclination angle (second angle) of each second inclined surface 35b with respect to the organic functional layer 50 is equal to each other, for example. The magnitudes of the first angle and the second angle are, for example, equal to each other. However, the magnitudes of the first angle and the second angle may be different from each other.

The first inclined surface 35a and the second inclined surface 35b are formed in the same shape and size, for example. It is preferable that the dimension of the first inclined surface 35 a and the second inclined surface 35 b in the short direction (the rectangular short dimension) is sufficiently larger than the wavelength of the light generated in the organic functional layer 50.

For example, the first and second

inclined surfaces

35a and 35b are arranged along the same plane. More specifically, the first and second

inclined surfaces

35 a and 35 b are arranged along one plane parallel to the organic functional layer 50, for example. That is, the distance from the organic functional layer 50 to each first inclined surface 35a is equal to the distance from the organic functional layer 50 to each second inclined surface 35b.

For example, the first light reflection film 25 is formed along one of the first inclined surface 35a and the second inclined surface 35b adjacent to each other. For example, the first light reflecting film 25 is formed along each of the plurality of second inclined surfaces 35b. For example, the first light reflecting film 25 is formed along the entire surface of the second inclined surface 35b. However, the 1st light reflection film 25 may be formed along a part of 2nd inclined surface 35b like the Example mentioned later.

The first light reflecting film 25 is made of a material having high reflectivity, for example, a metal such as Ag or Al. For example, the first light reflecting film 25 is formed by obliquely depositing a metal film on the lower surface of the second light-transmitting layer 120, whereby one of the first inclined surface 35a and the second inclined surface 35b (for example, the second inclined surface). A metal film is selectively formed on the surface 35b).

The second light transmissive layer 120 is made of a light transmissive material such as glass or resin. When the 2nd translucent layer 120 is comprised with glass, the refractive index of the 2nd translucent layer 120 is about 1.5, for example. The second light transmissive layer 120 may be a light transmissive film. The refractive index of the second light transmissive layer 120 is smaller than the refractive index of the first light transmissive layer 110.

The refractive index of the first light transmissive layer 110 is larger than the refractive index of the second light transmissive layer 120. This facilitates extraction of light from the first electrode 40 side to the first light transmissive layer 110 side. The refractive index of the first light transmissive layer 110 is, for example, about the same as the refractive index of the first electrode 40. The first light transmissive layer 110 includes, for example, an epoxy resin having a refractive index of about 1.8 and a barrier film that suppresses the influence on the organic material. Alternatively, the first light transmissive layer 110 may be formed of a high refractive index material containing nanoparticles using BaTiO ₃ or a high refractive index nanocomposite thin film. However, the first light transmissive layer 110 may be made of the same material as the organic functional layer 50.

The refractive index of the first light transmitting layer 110 is, for example, not less than the refractive index of the first electrode 40 and not more than 2.3.

The first light-transmitting layer 110 is configured, for example, by applying an organic material to the lower surface of the second light-transmitting layer 120 and curing it. Accordingly, the upper surface 111 of the first light transmissive layer 110 has a shape reflecting the uneven shape of the lower surface of the second light transmissive layer 120. However, the first light transmissive layer 110 may be attached to the second light transmissive layer 120 after being formed separately from the second light transmissive layer 120.

The first electrode 40 is configured, for example, by sputtering a metal oxide conductor such as ITO or IZO on the lower surface 112 of the first light transmitting layer 110. Furthermore, for example, a partition wall is formed on the lower surface of the first electrode 40.

The organic functional layer 50 is configured by depositing or applying an organic material including a light emitting layer between the partition walls. The second electrode 60 is configured by evaporating a metal material on the lower surface of the organic functional layer 50.

Note that the surface (lower surface) of the first light transmitting layer 110 opposite to the second light transmitting layer 120 side and one surface (upper surface) of the first electrode 40 are in contact with each other. Further, the other surface (lower surface) of the first electrode 40 and one surface (upper surface) of the organic functional layer 50 are in contact with each other. Further, the other surface (lower surface) of the organic functional layer 50 and one surface (upper surface) of the second electrode 60 are in contact with each other. However, another layer may exist between the first light-transmissive layer 110 and the first electrode 40. Similarly, another layer may exist between the first electrode 40 and the organic functional layer 50. Similarly, another layer may exist between the organic functional layer 50 and the second electrode 60.

4 (a) to 4 (c) and FIGS. 5 (a) to 5 (c) show how many paths until the light generated in the organic functional layer 50 is emitted to the outside in the light emitting device according to the present embodiment. It is sectional drawing which illustrated this. 4A to 4C and FIGS. 5A to 5C, the region R1 is on the low refractive index side (second light transmitting layer 120), and the region R2 is on the high refractive index side (first light transmitting layer). Optical layer 110). 4 (a) to 4 (c) and FIGS. 5 (a) to 5 (c) are particularly for explaining the function of the lower interface 35 of the second light transmitting layer 120. FIG.

Here, since the first light-transmissive layer 110, the first electrode 40, and the organic functional layer 50 have, for example, the same refractive index, refraction and reflection do not occur at the interfaces. Moreover, the uneven structure (arrangement of the first inclined surface 35a and the second inclined surface 35b) of the interface 35 on the light emitting layer side in the second light transmitting layer 120 is periodic. Furthermore, the thickness of the first light transmitting layer 110 and the second light transmitting layer 120 is about 10 μm, for example, whereas the thickness of the first electrode 40 and the organic functional layer 50 is about 100 nm, for example. The thicknesses of the first electrode 40 and the organic functional layer 50 are negligible compared to the thicknesses of the first light transmitting layer 110 and the second light transmitting layer 120. From these facts, even if it is considered that the second electrode 60 and the light emitting point are present at a position on the plane c in contact with the top of the protrusion on the light emitting layer side in the second light transmitting layer 120, there is substantially a problem. Absent. Accordingly, the following description will be made with reference to FIGS. 4A to 4C and FIGS. 5A to 5C assuming that the second electrode 60 and the light emitting point are located on the plane c.

As shown in FIG. 4A, the light ray A is incident on the first light transmitting layer 110 (region) at an angle θ1 with respect to the normal line n1 of the surface a1 (second inclined surface 35b) having the first light reflecting film 25. The surface a1 is reached from the R2) side. The light ray A is reflected by the surface a1, and then reaches the surface b1 at an angle θ2 with respect to the normal line n2 of the surface b1 (first inclined surface 35a) adjacent to the surface a1. When the angle θ2 is less than the critical angle, the light beam A is refracted at the surface b1 and is incident on the second light transmitting layer 120 at the angle θ3, and is adjacent to the surface b1 side at the adjacent surface a2 (second inclined surface 35b). Reflects with a directional component and travels toward interface 36.

As shown in FIG. 4B, the angle θ1 of the light beam B is larger than the angle θ1 of the light beam A. Similarly to the light ray A, the light beam B is reflected by the surface a1 and then refracted by the surface b1, and enters the second light transmitting layer 120 (region R1) from the first light transmitting layer 110 (region R2). Reflected with a direction component on the surface b2 side, which is the first inclined surface 35a opposite to the surface b1 at a2, and travels toward the interface 36.

As shown in FIG. 4 (c), the light ray C is almost parallel to the surface a1. The light ray C is refracted at the surface b1 and enters the second light-transmitting layer 120 (region R1) from the first light-transmitting layer 110 (region R2) and travels toward the interface 36.

As shown in FIG. 5 (a), the light ray D reflected by the surface a1 and returning to the original is reflected by the plane c which is the upper surface of the second electrode 60 and travels to the surface b1. Since the light beam D is incident on the surface b1 perpendicularly, the light beam D is directly incident on the second light-transmitting layer 120 (region R1) from the first light-transmitting layer 110 (region R2) and travels toward the interface 36.

As shown in FIG. 5B, the light beam E is a light beam having a polarity different from that of the angle θ1 of the light beam A, and enters the surface a1 from the left side of the normal line n1. The light beam E is reflected on the surface a1, reflected on the plane c which is the upper surface of the second electrode 60, and then reflected again on the surface a1. Thereafter, the light beam E enters the second light transmitting layer 120 (region R1) from the surface b1, reflects off the surface a2, and travels toward the interface 36.

As shown in FIG. 5 (c), the light beam F is incident on the surface b1 at an angle greater than or equal to the total reflection angle. The light beam F totally reflected by the surface b1 is reflected by the surface a1, then reflected by the plane c which is the upper surface of the second electrode 60, and then reaches the surface b1 again. The light beam F further enters the second light transmitting layer 120 (region R1) from the surface b1, and then travels toward the interface 36.

In this way, light rays that reach the interface 35 in various directions can be directed toward the interface 36 by the functions of the first inclined surface 35a, the second inclined surface 35b, and the first light reflecting film 25 of the interface 35.

In addition, a plurality of protrusions 70 are formed on the interface 36, and each protrusion 70 includes three or more inclined surfaces that are inclined in different directions with respect to the organic functional layer 50. At least one of them is not orthogonal to the organic functional layer 50. For example, each protrusion 70 is formed in a polygonal pyramid shape, a conical shape, or a hemispherical shape. Therefore, even for light that cannot be changed upward sufficiently by the functions of the first inclined surface 35a, the second inclined surface 35b, and the first light reflecting film 25 of the interface 35, the light is sufficiently increased by the function of the inclined surface of the protrusion 70. It can be changed upward so that it can be taken out from the light emitting device. Therefore, the light extraction efficiency of the light emitting device can be improved. Further, with respect to the light traveling from the interface 35 toward the interface 36, the path is directed upward by the inclined surface of the projection 70 of the interface 36 not directly at a position far from the light emission point of the light but directly above the light emission point. Can be changed. Therefore, there is a high possibility that the direction of the light can be changed to a direction in which the light can be extracted from the light extraction surface d before the light is attenuated.

Next, as a comparative example, a light emitting device in which the light reflecting film (first light reflecting film 25) is not formed on the interface 35 and the upper surface 121 of the second light transmitting layer 120 is flat will be described. FIG. 6A, FIG. 6B, FIG. 6C, FIG. 7A, FIG. 7B, and FIG. 7C are generated in the organic functional layer in the light emitting device according to the comparative example. It is sectional drawing which illustrated the path | route until emitted light was discharge | released outside. The angles of the light rays A to F shown in FIGS. 6 (a) to 6 (c) and FIGS. 7 (a) to 7 (c) are shown in FIGS. 4 (a) to 4 (c) and 5 respectively. The angles are the same as those of the light rays A to F shown in (a) to FIG. 5 (c).

In the comparative example, among the light beams A to F, the light beam A (FIG. 6A), the light beam B (FIG. 6B), the light beam E (FIG. 7B), and the light beam F (FIG. 7C). ), The angles toward the interface 36 are respectively gentle. Therefore, in the comparative example, the possibility that the light is totally reflected at the interface 36 (the possibility that the light is not emitted outside from the light extraction surface d) is higher than that in the present embodiment. That is, according to the present embodiment, the light extraction efficiency can be increased as compared with the comparative example.

Next, an example of the layer structure of the organic functional layer 140 will be described.

FIG. 8 is a view showing a first example of the layer structure of the organic functional layer 50. The organic functional layer 50 has a structure in which a hole injection layer 51, a hole transport layer 52, a light emitting layer 53, an electron transport layer 54, and an electron injection layer 55 are stacked in this order. That is, the organic functional layer 50 is an organic electroluminescence light emitting layer. Instead of the hole injection layer 51 and the hole transport layer 52, one layer having the functions of these two layers may be provided. Similarly, instead of the electron transport layer 54 and the electron injection layer 55, one layer having the functions of these two layers may be provided.

In the example of FIG. 8, the light emitting layer 53 is, for example, a layer that emits red light, a layer that emits blue light, a layer that emits yellow light, or a layer that emits green light. In this case, for example, in a plan view, a region having the light emitting layer 53 that emits red light, a region having the light emitting layer 53 that emits green light, and a region having the light emitting layer 53 that emits blue light are repeated. It may be provided. In this case, when each region emits light simultaneously, the light emitting device emits light in a single light emission color such as white.

Note that the light emitting layer 143 may be configured to emit light in a single light emission color such as white by mixing materials for emitting a plurality of colors.

FIG. 9 is a diagram showing a second example of the layer structure of the organic functional layer 50. The light emitting layer 53 of the organic functional layer 50 has a structure in which light emitting

layers

53a, 53b, and 53c are laminated in this order. The

light emitting layers

53a, 53b, and 53c emit light of different colors (for example, red, green, and blue). The

light emitting layers

53a, 53b, and 53c emit light at the same time, so that the light emitting device emits light in a single emission color such as white.

According to the embodiment as described above, the interface 35 has a plurality of first inclined surfaces 35a and a plurality of second inclined surfaces 35b. Therefore, light incident on the interface 35 at an angle greater than the critical angle can be reduced, and total reflection at the interface 35 can be suppressed. As a result, light with a large angle can be easily incident on the second light transmitting layer 120 from the first light transmitting layer 110, so that the light extraction efficiency is improved. In particular, in the first inclined surface 35a and the second inclined surface 35b closer to the light emitting layer, the effect of improving the light extraction efficiency by allowing light having a large angle to enter the adjacent layer is great (see FIG. 1). The first light reflection film 25 is formed along at least one of the plurality of first inclined surfaces 35a and the plurality of second inclined surfaces 35b. Thereby, the inclined surface on which the light reflecting film (first light reflecting film 25) is not formed transmits light, and the inclined surface on which the light reflecting film is formed reflects light. By having a combination of these inclined surfaces, it is possible to increase the probability that the direction of light can be converted into a direction that can be extracted from the light extraction surface d at the interface 35. Therefore, the light extraction efficiency of the light emitting device can be improved.

In addition, the light emitting device includes a first electrode 40 disposed between the organic functional layer 50 and the first light transmitting layer 110, and the first electrode 40 is located on the organic functional layer 50 side in the first light transmitting layer 110. The refractive index of the first translucent layer 110 that is in contact with the surface is not less than the refractive index of the first electrode 40 and not more than 2.3. This facilitates extraction of light from the first electrode 40 toward the first light transmissive layer 110 and suppresses a decrease in light extraction efficiency from the first light transmissive layer 110 to the second light transmissive layer 120. be able to.

The first light reflecting film 25 is formed along one of the first inclined surface 35a and the second inclined surface 35b adjacent to each other. Thereby, since the periodicity of the arrangement of the first light reflecting film 25 at the interface 35 can be provided, the extraction efficiency can be improved evenly in any region of the light emitting device.

Further, since the first light reflecting film 25 is disposed along each of the plurality of second inclined surfaces 35b, the periodicity of the arrangement of the first light reflecting film 25 at the interface 35 can be made more uniform. Therefore, the extraction efficiency can be improved more uniformly in any region of the light emitting device.

Further, when the plurality of protrusions 70 include the protrusions 70 formed in the shape of cones, the protrusions 70 include three or more inclined surfaces that are inclined in different directions with respect to the organic functional layer 50, and A structure in which at least one of these inclined surfaces is not orthogonal to the organic functional layer 50 can be easily realized.

In addition, when the plurality of protrusions 70 include protrusions 70 formed in a polygonal pyramid shape, the gap between the protrusions 70 adjacent to each other should be made as small as possible, and the plurality of protrusions 70 should be arranged with as little gap as possible. It can be easily realized. For example, as shown in FIG. 2A, the plurality of quadrangular pyramid-shaped projections 70 can be arranged in a matrix without any gap.

In addition, when the plurality of protrusions 70 includes a conical protrusion 70, the side surface of the conical protrusion 70 has a very large number of angles compared to the protrusion 70 having a pyramid shape or the like. Of inclined surfaces (of virtually infinite kinds of angles). For this reason, it can be expected to improve the light extraction efficiency at various angles.

In addition, when the plurality of protrusions 70 include a hemispherical protrusion 70, the outer surface of the hemispherical protrusion 70 has an extremely large number of angles compared to the protrusion 70 having a pyramid shape or the like. Of inclined surfaces (of virtually infinite kinds of angles). For this reason, it can be expected to improve the light extraction efficiency at various angles. Furthermore, the outer surface of the projection 70 formed in a hemispherical shape includes inclined surfaces having a very large number of angles (substantially infinite types of angles) in a side view as compared with the conical projection 70. For this reason, it can be expected that the light extraction efficiency of more angles can be improved as compared with the case where the conical protrusion 70 is used.

(Example 1)
In Example 1, an example of a more specific configuration of the light emitting device according to the embodiment will be described. 10A is a plan view of the light-emitting device according to Example 1, and FIG. 10B is a cross-sectional view taken along the line CC in FIG. 10A. In FIGS. 10B and 10A, the top and bottom are reversed from those in FIG.

The first electrode 40 constitutes an anode. The plurality of first electrodes 40 each extend in the Y direction in a strip shape. Adjacent first electrodes 40 are spaced apart at regular intervals in the X direction orthogonal to the Y direction. Each of the first electrodes 40 is made of, for example, a metal oxide conductor such as ITO or IZO. In addition, the 1st electrode 40 may be a metal thin film which has the thickness of the grade which has translucency. The refractive index of the first electrode 40 is, for example, about the same as that of the first light-transmitting layer 110 (for example, the refractive index is about 1.8). A bus line (bus electrode) 72 for supplying a power supply voltage to the first electrode 40 is formed on each surface of the first electrode 40. An insulating film is formed on the first light transmitting layer 110 and the first electrode 40. A plurality of stripe-shaped openings each extending in the Y direction are formed in the insulating film. Thereby, a plurality of partition walls 71 made of an insulating film are formed. Each opening formed in the insulating film reaches the first electrode 40, and the surface of each first electrode 40 is exposed at the bottom of the opening. An organic functional layer 50 is formed on the first electrode 40 in each opening of the insulating film. The organic functional layer 50 is configured by laminating a hole injection layer 51, a hole transport layer 52, a light emitting layer 53 (

light emitting layers

53R, 53G, 53B), and an electron transport layer 54 in this order. Examples of materials for the hole injection layer 51 and the hole transport layer 52 include aromatic amine derivatives, phthalocyanine derivatives, porphyrin derivatives, oligothiophene derivatives, polythiophene derivatives, benzylphenyl derivatives, compounds in which tertiary amines are linked by fluorene groups, hydrazones. Derivatives, silazane derivatives, silanamine derivatives, phosphamine derivatives, quinacridone derivatives, polyaniline derivatives, polypyrrole derivatives, polyphenylene vinylene derivatives, polythienylene vinylene derivatives, polyquinoline derivatives, polyquinoxaline derivatives, carbon and the like. The

light emitting layers

53R, 53G, and 53B are made of a fluorescent organometallic compound that emits red light, green light, and blue light, respectively. The

light emitting layers

53R, 53G, and 53B are arranged side by side in a state of being separated from each other by the partition wall portion 71. That is, the organic functional layer 50 forms a plurality of light emitting regions separated by the partition wall 71. An electron transport layer 54 is formed so as to cover the surfaces of the

light emitting layers

53R, 53G, 53B and the partition wall 71. A second electrode 60 is formed so as to cover the surface of the electron transport layer 54. The second electrode 60 constitutes a cathode. The second electrode 60 is formed in a strip shape. The second electrode 60 is made of a metal or alloy such as Al or Ag having a low work function and high reflectivity. The refractive index of the organic functional layer 50 is about the same as that of the first electrode 40 and the first light transmitting layer 110 (for example, the refractive index is about 1.8).

In this manner, the

light emitting layers

53R, 53G, and 53B that emit red, green, and blue light, respectively, are repeatedly arranged in a stripe shape, and red light is emitted from the surface of the second light transmissive layer 120 that serves as the light extraction surface d. , Green and blue light are mixed at an arbitrary ratio to emit light that is recognized as a single emission color (for example, white).

Also in Example 1, the same effect as the above embodiment can be obtained.

(Example 2)
FIG. 11A and FIG. 11B are cross-sectional views of the light emitting device according to this example. FIG. 11A corresponds to FIG. 2B, and FIG. 11B corresponds to FIG. In the above description, the first light transmissive layer 110 and the first electrode 40 are separately provided. However, as shown in FIGS. 11A and 11B, the first light transmissive layer 110 is formed of a light transmissive electrode. You may have the function of. That is, in this case, the first light transmissive layer 110 is made of a light transmissive conductor such as a metal oxide conductor such as ITO. According to this embodiment, since the first light transmissive layer 110 also functions as a light transmissive electrode, the number of components of the light emitting device can be reduced.

(Example 3)
FIG. 12A is a cross-sectional view showing a part of the light emitting device according to this example. In this light-emitting device, the top of the gable roof-shaped ridge 31 and the valley between the adjacent ridges 31 constituting the concavo-convex shape of the upper surface of the first light-transmitting layer 110 are substantially from the organic functional layer 50. It has

parallel surfaces

31a and 31b. The first light reflecting film 25 is not formed on the

surfaces

31a and 31b, and the

surfaces

31a and 31b are light transmitting surfaces. That is, the interface 35 of the light emitting device according to the present embodiment has the

surfaces

31 a and 31 b that are light transmission surfaces formed in parallel to the organic functional layer 50.

By making the

surfaces

31a and 31b substantially parallel to the organic functional layer 50 light transmitting surfaces, it is possible to easily extract light rays that are substantially orthogonal to the organic functional layer 50 to the outside. With respect to the light in such a direction, it is possible to improve the light extraction efficiency by extracting the light outside without being reflected by the first light reflection film 25.

Example 4
FIG. 12B is a cross-sectional view showing a part of the light emitting device according to this example. As shown in FIG. 12B, the

surfaces

31a and 31b may be covered with the first light reflecting film 25 so that the

surfaces

31a and 31b substantially parallel to the organic functional layer 50 become light transmission surfaces. Good. That is, the film thickness of the part covering the

surfaces

31a and 31b in the first light reflection film 25 is smaller than the film thickness of the part forming the light reflection surface in the first light reflection film 25. It is possible to form such a film thickness distribution by forming the first light reflecting film 25 by oblique vapor deposition. According to the present embodiment, the same effect as that of the third embodiment can be obtained.

(Example 5)
FIG. 13A is a cross-sectional view showing a part of the light emitting device according to this example, FIG. 13B is a plan view showing a part of the first light transmitting layer 110 in this example, and FIG. It is a perspective view which shows a part of 1st translucent layer 110 in an Example. In the present embodiment, the shape of each protrusion 31 on the upper surface of the first light transmissive layer 110 is changed. As shown in these drawings, each of the protrusions 31 has a trapezoidal cross-sectional shape, and the upper base is a surface 31 d substantially parallel to the organic functional layer 50. In other words, the 1st inclined surface 35a and the 2nd inclined surface 35b which comprise the protrusion 31 are mutually spaced apart in those arrangement directions. The first light reflection film 25 is formed on the surface 31d, and the surface 31d forms a light transmission surface. In this way, by making the surface 31d substantially parallel to the organic functional layer 50 as a light transmission surface, the light rays perpendicularly incident on the surface 31d are incident on the first light reflecting film as in the third embodiment. Since the light is emitted to the outside without being reflected by 25, the light extraction efficiency can be improved.

(Example 6)
FIG. 14 is a cross-sectional view showing a part of the light emitting device according to the present embodiment. In the present embodiment, the adjacent protrusions 31 are separated from each other in the arrangement direction thereof. A surface 31 d substantially parallel to the organic functional layer 50 is formed between adjacent protrusions 31. The first light reflection film 25 is formed on the surface 31d, and the surface 31d forms a light transmission surface. According to the present embodiment, the same effect as that of the fifth embodiment can be obtained.

(Example 7)
FIG. 15 is a cross-sectional view showing a part of the light emitting device according to the present embodiment. In this light emitting device, the light reflecting structure 22 formed on the interface 35 is different from the above embodiment. That is, in the above-described embodiment, the light reflecting structure is configured by the first light reflecting film 25, whereas the light reflecting structure 22 in the present example has the first light reflecting film 25 and the second light transmitting film. A low refractive index film 21 made of a material having a refractive index lower than that of the layer 120 (for example, SiO ₂ ) is laminated. The light ray I incident on the light reflecting structure 22 at an incident angle larger than the critical angle from the second light transmitting layer 120 side is totally reflected at the interface between the second light transmitting layer 120 and the low refractive index film 21 and is reflected on the interface 36. Head. Here, the reflectivity of the total reflection is 100%, and the reflectivity of the reflective film such as metal is about 90%. Therefore, the total reflection by the low refractive index film 21 is performed only by the first light reflection film 25. Compared with the case of reflecting, it is possible to expect an improvement in reflectance and, in turn, an improvement in light extraction efficiency. On the other hand, the light beam J incident on the light reflecting structure 22 at an incident angle smaller than the critical angle from the second light transmitting layer 120 side is transmitted through the low refractive index film 21 and reflected by the surface of the first light reflecting film 25. Head to interface 36. In this way, by disposing the low refractive index film 21 on the first light reflecting film 25, a part of the light rays (light rays I and the like) are totally reflected by the low refractive index film 21 and directed toward the interface 36. Therefore, it is possible to expect an improvement in reflectance and, in turn, an improvement in light extraction efficiency.

FIG. 15 shows an example in which the low refractive index film 21 is in contact with the second light transmitting layer 120 and the first light reflecting film 25 is in contact with the first light transmitting layer 110. The arrangement of the film 25 and the low refractive index film 21 may be interchanged.

FIGS. 16A to 16E are cross-sectional views showing a method for manufacturing a light emitting device according to this example.

First, a second light-transmitting layer 120 having a plurality of protrusions 70 formed on the upper surface 121 and an uneven shape formed on the lower surface 122 is prepared (FIG. 16A).

Next, the low refractive index film 21 made of SiO ₂ or the like having a refractive index lower than that of the second light transmitting layer 120 is formed on the lower surface 122 of the second light transmitting layer 120 by sputtering or the like. Thereafter, the low refractive index film 21 is partially removed by a lift-off method, an etching method, or the like, and the low refractive index film 21 is patterned (FIG. 16B).

Next, the first light reflection film 25 made of a metal having a high reflectance such as Ag or Al is formed on the lower surface of the second light transmission layer 120 by an oblique deposition method or the like. The first light reflecting film 25 is laminated on the low refractive index film 21 to form, for example, the light reflecting structure 22 along the second inclined surface 35b (FIG. 16C).

Next, a UV curable resin having a refractive index higher than the refractive index of the second light transmissive layer 120 and similar to the refractive index of the first electrode 40 and the organic functional layer 50 is formed on the lower surface of the second light transmissive layer 120. Apply. Thereafter, the UV curable resin is irradiated with ultraviolet rays to be cured. As a result, the first light-transmitting layer 110 in contact with the uneven shape of the second light-transmitting layer 120 and the light reflecting structure 22 is formed on the lower surface of the second light-transmitting layer 120 (FIG. 16D).

Next, a transparent conductive film made of a metal oxide conductor such as ITO is formed on the lower surface of the first light transmissive layer 110 by sputtering or the like, and is patterned by etching to form the first electrode 40. Next, a photosensitive resist (not shown) is applied so as to cover the first electrode 40. Thereafter, a plurality of openings reaching the first electrode 40 are formed in the photosensitive resist through exposure and development processing. Thereby, the partition part which separates an organic functional layer for every luminescent color is formed. Next, a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer are stacked on the first electrode 40 by applying an organic material inside each of the plurality of openings by an inkjet method. The organic functional layer 50 to be formed is formed. Next, using a mask having an opening corresponding to the pattern of the second electrode 60, an electrode material such as Al or Ag is deposited on the organic functional layer 50 in a desired pattern by vapor deposition or the like. The electrode 60 is formed (FIG. 16E). It is good also as forming a sealing layer on the 2nd electrode 60 as needed. Through the above steps, the light-emitting device according to this example is obtained.

(Example 8)
FIG. 17 is a cross-sectional view showing a part of the light emitting device according to this example. In the present embodiment, an example in which the light reflection structure formed by the low refractive index film 21 and the first light reflection film 25 is changed from the seventh embodiment will be described. As shown in FIG. 17, the light reflecting structure 22 a has a sandwich structure in which a low refractive index film 21 having a refractive index smaller than that of the second light transmitting layer 120 holds the first light reflecting film 25. Thereby, it is possible to totally reflect the light incident on the light reflecting structure 22a from the second light transmitting layer 120 side and the first light transmitting layer 110 side, and it is possible to further reduce the reflection loss compared to the seventh embodiment. It becomes.

Example 9
FIG. 18 is a cross-sectional view showing a part of the light emitting device according to this example. In the present embodiment, a modification of the light reflecting structure including the first light reflecting film 25 and the low refractive index layer will be described. As shown in FIG. 18, the low refractive index layer of the light reflecting structure 24 includes a gap portion 23 provided between the second light transmitting layer 120 and the first light transmitting layer 110. That is, the light reflecting structure 24 is constituted by the gap portion 23 and the first light reflecting film 25. The gap 23 may be filled with air or other gas having a refractive index smaller than that of the second light transmissive layer 120, or may be a vacuum. Since the refractive index of the gap 23 is smaller than the refractive index of the second light transmissive layer 120, the gap 23 has the same function as the low refractive index film 21 described above. FIG. 18 illustrates the case where the gap portion 23 is in contact with the second light transmission layer 120 and the first light reflection film 25 is in contact with the first light transmission layer 110. The arrangement with the one-light reflecting film 25 may be exchanged.

FIG. 19A to FIG. 19D are cross-sectional views showing a method for manufacturing a light emitting device according to this example.

First, a second light-transmissive layer 120 having a plurality of protrusions 70 formed on the upper surface 121 and an uneven shape formed on the lower surface 122 is prepared (FIG. 19A).

Next, a first light reflecting film 25 made of a metal having a high reflectance such as Ag or Al is formed on the lower surface 122 of the second light transmitting layer 120 by an oblique deposition method or the like (FIG. 19B). .

Next, the first light transmissive layer 110 is prepared. The first light transmissive layer 110 is made of an epoxy resin having a refractive index larger than that of the second light transmissive layer 120 and having a refractive index comparable to that of the first electrode 40 and the organic functional layer 50. On the upper surface of the first light transmissive layer 110, a concavo-convex shape that meshes with the concavo-convex shape on the lower surface of the second light transmissive layer 120 is formed. Furthermore, a minute protrusion 32 is formed on the upper surface of the first light transmitting layer 110 (FIG. 19C).

Next, using the minute protrusions 32 as spacers, the uneven shape on the lower surface of the second light transmitting layer 120 and the uneven shape on the upper surface of the first light transmitting layer 110 are brought into contact with each other. The minute protrusions 32 are in contact with the first light reflecting film 25, and a gap 23 is formed between the first light reflecting film 25 and the upper surface of the first light transmissive layer 110. As a result, a light reflecting structure 24 including the first light reflecting film 25 and the gap 23 is formed between the second light transmitting layer 120 and the first light transmitting layer 110 (FIG. 19D). .

The first light reflecting film 25 may be formed on the upper surface of the first light transmitting layer 110, or formed on both the upper surface of the first light transmitting layer 110 and the lower surface of the second light transmitting layer 120. It may be. Further, the minute protrusions 32 functioning as spacers may be provided on the lower surface of the second light transmitting layer 120, or provided on both the upper surface of the first light transmitting layer 110 and the lower surface of the second light transmitting layer 120. It may be done. In addition, a structure separate from the first light-transmitting layer 110 and the second light-transmitting layer 120 is disposed between the upper surface of the first light-transmitting layer 110 and the lower surface of the second light-transmitting layer 120. It may function as a spacer.

(Example 10)
20 (a) to 20 (d) are cross-sectional views illustrating a method for manufacturing a light-emitting device according to this example. In this embodiment, an example in which the light reflecting structure 24 including the first light reflecting film 25 and the gap 23 is changed and a manufacturing method thereof will be described.

First, the manufacturing method will be described. First, a second light transmitting layer 120 having a plurality of protrusions 70 formed on the upper surface 121 and an uneven shape formed on the lower surface 122 is prepared (FIG. 20A).

On the other hand, the first light transmissive layer 110 is prepared in the same manner as in Example 9 above. However, in the present embodiment, the minute protrusion 32 is not formed on the first light transmitting layer 110.

Next, a first light reflecting film 25 made of a metal having a high reflectance such as Ag or Al is selectively formed on the upper surface of the first light transmitting layer 110 by an oblique deposition method or the like (FIG. 20B). )).

Next, using the difference in thermal expansion coefficient between the first light transmissive layer 110 and the first light reflecting film 25, a buckling structure (sag-like swell) is formed in the first light reflecting film 25. That is, the first light reflection film 25 is shaped to wave up and down in a sectional view. For example, a buckling structure can be formed in the first light reflection film 25 by heating the first light reflection film 25 to about 100 ° C. and then lowering the temperature to room temperature (FIG. 20C).

Next, the concave / convex shape on the upper surface of the first light-transmitting layer 110 and the concave / convex shape on the lower surface of the second light-transmitting layer 120 are brought into contact with each other with the first light reflecting film 25 having the buckling structure interposed therebetween. Match. Thereby, between the 1st light transmission layer 110 and the 2nd light transmission layer 120, the space | gap part 23 produced with the buckling structure of the 1st light reflection film 25 and the 1st light reflection film 25, A light reflecting structure 24 is formed (FIG. 22D).

Therefore, the light emitting device according to the present embodiment has the light reflecting structure 24 including the first light reflecting film 25 and the gap portion 23 generated with the buckling structure of the first light reflecting film 25. . According to the present embodiment, the same effect as that of the ninth embodiment can be obtained.

(Example 11)
FIG. 21 is a cross-sectional view of the light emitting device according to this example. The light emitting device according to this example has a light-transmitting protective film 130 in addition to the configuration of the above embodiment. The protective film 130 covers the plurality of protrusions 70 on the upper surface 121 of the second light transmissive layer 120. The protective film 130 may be made of an inorganic material such as a silicon oxide film, or may be made of the same material as the first electrode 40. The protective film 130 is formed using, for example, a vapor deposition method such as a CVD method or a sputtering method. In this embodiment, the light transmissive layer 100 includes a protective film 130 in addition to the first light transmissive layer 110 and the second light transmissive layer 120. Further, the upper surface of the protective film 130 constitutes a light extraction surface d.

Also in this example, the same effect as in the embodiment can be obtained. In addition, since the second light transmissive layer 120 is protected by the protective film 130, the durability of the light emitting device can be improved.

Example 12
FIG. 22 is a cross-sectional view of the light emitting device according to this example. In the light emitting device according to this example, a translucent protective member (for example, protective glass) 140 is disposed above the second light transmissive layer 120 of the light emitting device according to the above embodiment. The protection member 140 is supported on the base member 80 via the support member 84, for example. On the base member 80, the light emitting device having the structure described in the above embodiment is fixed. The space surrounded by the base member 80, the protection member 140, and the support member 84 is sealed. Note that a gas (for example, air or inert gas) is filled between the protective member 140 and the second light transmissive layer 120. Here, the space between the protection member 140 and the second light transmissive layer 120 is the adjacent region 200. In the case of the present embodiment, the light transmissive layer 100 includes an adjacent region 200 made of a gas and a protective member 140 in addition to the first light transmissive layer 110 and the second light transmissive layer 120. Further, the upper surface of the protection member 140 constitutes a light extraction surface d.

Also in this example, the same effect as in the above embodiment can be obtained. Moreover, since the 2nd light transmission layer 120 is protected by the protection member 140, durability of a light-emitting device can be improved. Furthermore, part of the light reflected by the protective member 140 and returned to the second light transmissive layer 120 can also be converted into a direction that can be extracted from the light extraction surface d by being reflected by the interface 35.

(Example 13)
FIG. 23 is a cross-sectional view of the light emitting device according to this example. In this example, an example of a more specific configuration of the light emitting device according to Example 12 will be described. As shown in FIG. 23, the base member 80 can be a sealing body, for example. In the base member 80, a conductor 191 for electrically connecting the second electrode 60 to the outside is provided through the base member 80 at a portion covering the partition wall 71. According to this embodiment, the same effect as that of Embodiment 12 can be obtained.

(Example 14)
FIG. 24 is a perspective view of the light emitting device according to this example. 25A is a cross-sectional view of the light-emitting device according to the present embodiment as viewed in the direction of arrow A in FIG. 24, and FIG. 25B is a cross-sectional view of the light-emitting device according to the present embodiment as viewed in the direction of arrow B in FIG. FIG. FIG. 26 is a plan view of the interface 35 of the light emitting device according to this example. For example, this light-emitting device is configured in the same manner as the light-emitting device according to the above-described embodiment (FIG. 2) with respect to other configurations described below.

As shown in FIGS. 24 to 26, the interface 35 between the first light transmitting layer 110 and the second light transmitting layer 120 is either the first inclined surface 35 a or the second inclined surface 35 b with respect to the organic functional layer 50. A third inclined surface 35c inclined in a direction different from the inclined direction; and a fourth inclined surface 35d inclined in a direction opposite to the inclined direction of the third inclined surface 35c with respect to the organic functional layer 50. is doing. A plurality of third inclined surfaces are arranged such that the third inclined surfaces 35c and the fourth inclined surfaces 35d are alternately positioned in a second direction that is parallel to the organic functional layer 50 and intersects the first direction (arrow B direction). The surface 35c and the plurality of fourth inclined surfaces 35d are arranged side by side in the second direction. The second light reflection film 26 is formed along at least one of the plurality of third inclined surfaces 35c and the plurality of fourth inclined surfaces 35d. The second light reflecting film 26 is the same as the first light reflecting film 25.
Specifically, for example, the second light reflecting film 26 is formed along each of the plurality of fourth inclined surfaces 35d. In addition, the plurality of third inclined surfaces 35c are light-transmitting surfaces on which the second light reflecting film 26 is not formed.

As shown in FIG. 26, in plan view, a region R11 in which the first inclined surface 35a and the second inclined surface 35b are disposed, and a region R12 in which the third inclined surface 35c and the fourth inclined surface 35d are disposed. Are different from each other.
For example, the second direction is orthogonal to the first direction. That is, the second direction is, for example, the arrow A direction. The directions of the third inclined surface 35c and the fourth inclined surface 35d are, for example, directions obtained by rotating the first inclined surface 35a and the second inclined surface 35b by 90 degrees in the plane. However, the first direction and the second direction only need to cross each other, and the angle formed by the first direction and the second direction may be other than 90 degrees.

In the present embodiment, the direction of the inclined surface is changed for each region in the interface 35 as described above. The structure of the light emitting device in the region R11 and the structure of the light emitting device in the region R12 are configured in the same manner except that the direction of the inclined surface is different.

For example, as shown in FIG. 26, a plurality of first regions R11 (a region where the first inclined surface 35a and the second inclined surface 35b are arranged) and a plurality of second regions R12 (the third inclined surface 35c and the fourth inclined surface). And the area where the surface 35d is arranged) are alternately arranged in plan view. Specifically, for example, a plurality of first regions R11 and a plurality of second regions R12 are arranged adjacent to each other in a staggered manner.

In the second light-transmitting layer 120, the portion disposed in each first region R11 and the portion disposed in each second region R12 are formed as individual blocks and arranged side by side on the same plane. May be. In this case, the second light-transmitting layer 120 is formed as a plurality of blocks having the same shape, and a plurality of these blocks are arranged side by side with their directions different from each other by 90 degrees. Can be produced. Similarly, also about the 1st light transmission layer 110, the part arrange | positioned in each 1st area | region R11 and the part arrange | positioned in each 2nd area | region R12 are formed as a separate block, and they are on the same plane. They may be arranged side by side. However, the second light transmissive layer 120 and the first light transmissive layer 110 may be integrally formed as a whole.

According to the present embodiment, since there are inclined surfaces at many angles at the interface 35, it is possible to convert light at various angles into directions that can be extracted from the light emitting device at the interface 35. In the region R11, the first inclined surface 35a and the second electrode 60 having interfaces having different refractive indexes between the first light reflecting film 25 on the second inclined surface 35b and the second electrode 60 that is a reflective electrode. Even for a light beam having an angle that causes an operation pattern that repeats reflection between the inclined surface and the adjacent region R12, the inclined surface (third inclined surface 35c, fourth inclined surface 35d) having a different angle from the previous one is entered. It hits. As a result, even light of such an angle can be extracted from the operation pattern of repeated reflection and extracted to the air layer.
Similarly, in the region R12, the third inclined surface 35c and the second electrode having interfaces having different refractive indexes between the second light reflecting film 26 on the fourth inclined surface 35d and the second electrode 60 serving as the reflective electrode. Even for a light beam having an angle that causes an operation pattern that repeats reflection with respect to 60, by entering the adjacent region R11, inclined surfaces (first inclined surface 35a and second inclined surface 35b having different angles from that of the previous region). ). As a result, even light of such an angle can be extracted from the operation pattern of repeated reflection and extracted to the air layer.

In addition, a plurality of first regions R11 in which the first inclined surface 35a and the second inclined surface 35b are arranged, and a plurality of second regions R12 in which the third inclined surface 35c and the fourth inclined surface 35d are arranged are planar. They are arranged adjacent to each other alternately in view. Thereby, in the first region R11, the light having an angle that forms a repetitive reflection pattern that is not extracted from the light-emitting device is not located far from the first region R11 but is adjacent to the first region R11. It can be changed upward in the two regions R12. Therefore, there is a high possibility that the direction of the light can be changed to a direction in which the light can be extracted from the light extraction surface d before the light is attenuated. Similarly, in the second region R12, the light having an angle that forms a repetitive reflection pattern that is not extracted from the light emitting device is adjacent to the second region R12, not far from the second region R12. It can be changed upward in the first region R11. Therefore, there is a high possibility that the direction of the light can be changed to a direction in which the light can be extracted from the light extraction surface d before the light is attenuated.

(Example 15)
FIG. 27A is a perspective view of the light-emitting device according to the present example, and FIG. 27B is a cross-sectional view of the light-emitting device according to the present example when viewed in the direction of arrow A in FIG.

The light-emitting device according to Example 16 includes a first light reflecting film 25 disposed along the first inclined surface 35a and a first light reflecting film 25 disposed along the second inclined surface 35b.

For example, in FIG. 27B, with the region E as a boundary, the first light reflecting film 25 is formed along each first inclined surface 35a in the left region, and each second inclined surface is formed in the right region. A first light reflecting film 25 is formed along 35b.

According to the present example, in addition to the same effects as the above embodiment, the following effects can be obtained. That is, at the interface 35, the first light reflection film 25 can be oriented in two directions. Therefore, it is possible to increase the possibility that light having various angles can be extracted from the light emitting device to the outside.

As mentioned above, although embodiment and the Example were described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

For example, after the first light reflecting film 25 is deposited on the lower surface of the second light transmitting layer 120, the third light transmitting material made of a material having a softening point or a melting point lower than that of the second light transmitting layer 120 (for example, ITO or IZO). A layer is formed on the lower surface of the second light transmitting layer 120 by sputtering or vapor deposition, and a fourth light transmitting layer made of a high refractive index material is formed on the lower surface of the third light transmitting layer. Thereby, the 1st translucent layer 110 which consists of a 3rd translucent layer and a 4th translucent layer can be formed. Here, when the softening point of the high refraction material is about the same as or higher than that of the second light transmission layer 120, the second light transmission layer 120 of the high refraction material is directly formed on the lower surface of the second light transmission layer 120. The uneven shape (reverse V-groove shape) on the lower surface of the second light transmitting layer 120 is greatly broken (blunted), and the first inclined surface 35a and the second inclined surface 36b are not flat. On the other hand, after forming a third light-transmitting layer such as ITO or IZO as an intermediate layer, a fourth light-transmitting layer made of a high refractive material is formed, thereby forming a concave-convex shape on the lower surface of the second light-transmitting layer 120 ( Even if the reverse V-groove shape is slightly collapsed, it can be prevented from being largely collapsed.

Claims

An organic functional layer including a light emitting layer;
A translucent layer disposed on one side of the organic functional layer;
With
The surface opposite to the organic functional layer in the translucent layer constitutes a light extraction surface that emits light emitted by the light emitting layer,
The translucent layer is
In order from the side closer to the organic functional layer,
A first light transmissive layer;
A second light transmissive layer having an interface with the first light transmissive layer;
Have
The interface between the first light transmissive layer and the second light transmissive layer is a first inclined surface that is inclined with respect to the organic functional layer, and an inclination direction of the first inclined surface with respect to the organic functional layer A second inclined surface inclined in the opposite direction to
A plurality of the first inclined surfaces and a plurality of the second inclined surfaces are arranged in the first direction parallel to the organic functional layer such that the first inclined surfaces and the second inclined surfaces are alternately positioned. Arranged side by side in one direction,
An interface between the second light transmissive layer and an adjacent region that is a region adjacent to the second light transmissive layer opposite to the first light transmissive layer includes a plurality of protrusions;
A first light reflecting film is formed along at least one of the plurality of first inclined surfaces and the plurality of second inclined surfaces;
Each of the plurality of protrusions includes three or more inclined surfaces inclined in different directions with respect to the organic functional layer, and at least one of these inclined surfaces is defined with respect to the organic functional layer. Light emitting device that is not orthogonal.
A translucent electrode disposed between the organic functional layer and the first translucent layer;
The translucent electrode is in contact with the surface of the first translucent layer on the organic functional layer side,
2. The light emitting device according to claim 1, wherein a refractive index of the first light transmissive layer is equal to or higher than a refractive index of the light transmissive electrode and equal to or lower than 2.3.
3. The light emitting device according to claim 1, wherein the first light reflecting film is formed along one of the first inclined surface and the second inclined surface adjacent to each other.
4. The light emitting device according to claim 1, wherein the plurality of protrusions include protrusions formed in a cone shape.
The light emitting device according to claim 4, wherein the plurality of protrusions include protrusions formed in a polygonal pyramid shape.
The light emitting device according to claim 4 or 5, wherein the plurality of protrusions include a conical protrusion.
The light emitting device according to any one of claims 1 to 6, wherein the plurality of protrusions include a hemispherical protrusion.
The interface between the first light transmissive layer and the second light transmissive layer is inclined with respect to the organic functional layer in a direction different from any of the first inclined surface and the second inclined surface. 3 inclined surfaces, and a fourth inclined surface inclined in a direction opposite to the inclination direction of the third inclined surface with respect to the organic functional layer,
A plurality of the third inclined surfaces and a plurality of the third inclined surfaces are arranged so that the third inclined surfaces and the fourth inclined surfaces are alternately positioned in a second direction parallel to the organic functional layer and intersecting the first direction. Are arranged side by side in the second direction,
6. The second light reflecting film is formed along at least one of the plurality of third inclined surfaces and the plurality of fourth inclined surfaces. The light emitting device described.
An organic functional layer including a light emitting layer;
A translucent layer disposed on one side of the organic functional layer;
With
The surface opposite to the organic functional layer in the translucent layer constitutes a light extraction surface that emits light emitted by the light emitting layer,
The translucent layer is
In order from the side closer to the organic functional layer,
A first light transmissive layer;
A second light transmissive layer having an interface with the first light transmissive layer;
Have
The interface between the first light transmissive layer and the second light transmissive layer is a first inclined surface that is inclined with respect to the organic functional layer, and an inclination direction of the first inclined surface with respect to the organic functional layer A second inclined surface inclined in the opposite direction to
A plurality of the first inclined surfaces and a plurality of the second inclined surfaces are arranged in the first direction parallel to the organic functional layer such that the first inclined surfaces and the second inclined surfaces are alternately positioned. Arranged side by side in one direction,
An interface between the second light transmissive layer and an adjacent region that is a region adjacent to the second light transmissive layer opposite to the first light transmissive layer includes a plurality of protrusions;
A first light reflecting film is formed along at least one of the plurality of first inclined surfaces and the plurality of second inclined surfaces;
Each of the plurality of protrusions is a light emitting device formed in a polygonal pyramid shape, a conical shape, a polygonal frustum shape, a truncated cone shape, or a hemispherical shape.