WO2014109028A1

WO2014109028A1 - Light-emitting element

Info

Publication number: WO2014109028A1
Application number: PCT/JP2013/050284
Authority: WO
Inventors: 黒田　和男
Original assignee: パイオニア株式会社
Priority date: 2013-01-10
Filing date: 2013-01-10
Publication date: 2014-07-17

Abstract

This light-emitting element is provided with an organic functional layer (50) including a light-emitting layer, a first light-transmissive layer (110) arranged on the light extraction side relative to the organic functional layer (50), and a second light-transmissive layer (120) having a lower refractive index than the first light-transmissive layer (110) and embedded in the first light-transmissive layer (110). At least a part of the second light-transmissive layer (120) is a tilted part tilted relative to the light-emitting layer. The surface of the tilted part on the side of the organic functional layer (50) and the surface thereof on the light-extraction side both contact the first light-transmissive layer (110).

Description

Light emitting element

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

There is a light emitting element having an organic light emitting layer as one of the light emitting elements. In this light emitting element, 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. In the display device described in Patent Document 1, the thin film layer including the light emitting layer is closely fixed to the transparent substrate, and the angle conversion means for converting the emission angle of the light emitted from the light emitting layer and radiating the light to the outside is the transparent substrate. Is provided inside.

Patent Document 2 discloses an electroluminescence element in which a cathode, an electroluminescence layer, a transparent electrode layer, and a light transmitting body are arranged in this order, and the surface on the light transmitting body side of the transparent electrode layer is a light scattering uneven surface. Is described. Further, in Patent Document 2, a high refractive index layer having a refractive index equivalent to that of the transparent electrode layer is provided on the surface of the transparent electrode layer on the light transmitting body layer side, and the surface on the light transmitting body side of the high refractive index layer is irradiated with light. It also describes the use of a scattering uneven surface.

Further, in Patent Document 3, optical structures having different refractive indices from the surroundings are regularly arranged in a one-dimensional direction at intervals of about the emission wavelength, and organic EL (Electro Luminescence) light emission is caused by these optical structures. An organic EL light emitting element that converts light propagating in the element into a direction radiated from the organic EL light emitting element is described. The optical structure has a rectangular parallelepiped shape, a cylindrical shape, or the like composed of a plane orthogonal to the light emitting layer and a plane parallel to the plane.

JP-A-10-189251 JP 2004-296438 A JP 2004-311419 A

The organic EL light emitting element is configured, for example, by laminating a translucent electrode, an organic functional layer including a light emitting layer, and a metal electrode on a translucent substrate such as a glass substrate. In such an organic EL light emitting device, the following three factors can be cited as factors that reduce the light extraction efficiency. (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 element. In particular, light incident in an oblique direction with respect to a light-transmitting electrode having a relatively low light transmittance has a significant attenuation because the optical path length is 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. FIG. 1 shows a state in which light is emitted in a hemispherical form from the light emitting point P101 in order to make the drawing easy to see. In the current general light emitting element, only light (angled region R101 shown in FIG. 1) having an angle within about 20 degrees with respect to a line perpendicular to the translucent electrode can be extracted from the light emitting element. 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 P101. This is because the area of the region R102 is larger than that of the region R101 shown in FIG. For this reason, the inventor has improved the angle of the light extracted from the light emitting element within about 20 degrees with respect to a line perpendicular to the translucent electrode to about 25 degrees, for example, by improving 5 degrees. It was considered that the improvement effect of the light extraction efficiency is larger when the extraction efficiency of light having a larger angle (for example, light in the region R102 shown in FIG. 1) is improved by 5 degrees.

In the technique of Patent Document 1, since the light emitting layer is in close contact with the transparent substrate and the angle conversion means is disposed in the transparent substrate, light is entirely transmitted from the high refractive index light emitting layer to the low refractive index transparent substrate. It will be reflected. Therefore, it is difficult to improve the light extraction efficiency of the region R102 shown in FIG.

In the technique of Patent Document 2, basically, light is diffused on the concavo-convex surface. Therefore, the angle of light toward the reflective electrode is increased, the number of multiple reflections is increased, and the organic functional layer and the reflective electrode described above are increased. It is considered that the light extraction efficiency is not improved so much by the attenuation due to.

The technology of Patent Document 3 improves the light extraction efficiency in a narrow wavelength range. For this reason, there is a possibility that light emission characteristics in a broad wavelength range, which is one of the characteristics of the organic EL light emitting element, cannot be obtained sufficiently.

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

The invention according to claim 1 includes an organic functional layer including a light emitting layer,
A first light transmissive layer disposed on the light extraction side with respect to the organic functional layer;
A second light-transmitting layer having a refractive index lower than that of the first light-transmitting layer and embedded in the first light-transmitting layer;
With
At least a part of the second light transmissive layer is an inclined portion inclined with respect to the light emitting layer,
The surface on the organic functional layer side and the surface on the light extraction side in the inclined portion are inclined with respect to the light emitting layer, respectively.
In the light emitting element, a surface on the organic functional layer side and a surface on the light extraction side in the inclined portion are in contact with the first light transmitting layer.

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. It is sectional drawing of the light emitting element which concerns on embodiment. 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. 1 is a cross-sectional view of a light emitting device according to Example 1. FIG. 6 is a cross-sectional view of a light emitting device according to Example 2. FIG. 7 is a cross-sectional view of a light emitting device according to Example 3. FIG. 6 is a perspective view of a second light transmissive layer of a light emitting device according to Example 3. FIG. Each of FIGS. 9A to 9C is a cross-sectional view illustrating paths until light generated in the light emitting layer is emitted to the outside in the light emitting device according to the third embodiment. FIG. 10A is a plan view of the light-emitting element according to Example 4, and FIG. 10B is a cross-sectional view taken along the line CC in FIG. FIG. 11A is a cross-sectional view of the light emitting device according to Example 5, and FIG. 11B is a perspective view of the second light transmitting layer of the light emitting device according to Example 5. 6 is a cross-sectional view of a light emitting device according to Example 6. FIG. 6 is a cross-sectional view of a light emitting device according to Example 7. FIG. 14A is a cross-sectional view of the light emitting device according to Example 8, and FIG. 14B is a perspective view of the second light transmitting layer of the light emitting device according to Example 8. FIG. 15A is a perspective view of the second light transmitting layer of the light emitting device according to Example 9, and FIG. 15B is a cross-sectional view of the light emitting device according to Example 9. 16A is a cross-sectional view of the periphery of the second light-transmitting layer of the light-emitting element according to Example 10, and FIG. 16B is a diagram for explaining the effect of the light-emitting element according to Example 10. 12 is a cross-sectional view of a light-emitting element according to Example 11. FIG. It is sectional drawing of the light emitting element which concerns on Example 12. FIG. It is sectional drawing of the light emitting element which concerns on Example 13. 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 element according to the present embodiment includes an organic EL element. This light emitting element can be used as a light source for a display, a lighting device, an optical communication device, or the like.

FIG. 2 is a cross-sectional view of the light emitting device according to the embodiment.

The light emitting device according to the present embodiment includes an organic functional layer 50 including a light emitting layer, a first light transmissive layer 110 disposed on the light extraction side with respect to the organic functional layer 50, and refractive than the first light transmissive layer 110. And a second light-transmitting layer 120 embedded in the first light-transmitting layer 110 with a low rate. At least a part of the second light transmitting layer 120 is an inclined portion inclined with respect to the light emitting layer. The surface on the organic functional layer 50 side and the surface on the light extraction side in the inclined portion are inclined with respect to the light emitting layer, respectively, and the surface on the organic functional layer 50 side and the surface on the light extraction side in the inclined portion are first. 1 is in contact with the light transmissive layer 110. Here, being inclined with respect to the light emitting layer means being inclined with respect to the surface on which the light emitting layer extends, for example, being inclined with respect to the upper surface of the organic functional layer 50. Means. Further, being inclined with respect to the light emitting layer means not being parallel to the light emitting layer and not being orthogonal to the light emitting layer. The light extraction side means the light extraction surface d side described later.

Hereinafter, in order to simplify the description, description will be made assuming that the positional relationship (vertical relationship, etc.) of each component of the light emitting element is the relationship shown in each drawing. However, the positional relationship in this description is irrelevant to the positional relationship when the light emitting element is used.

In the present embodiment, the upper surface of the first light transmissive layer 110 (the surface opposite to the organic functional layer 50 side of the first light transmissive layer 110) is in contact with the light emission space 200 outside the light emitting element. The upper surface of the first light transmissive layer 110 constitutes a light extraction surface d that emits light from the light emitting element to the light emission space 200. The light emitting space 200 is an air layer and has a refractive index of 1. In addition, the light extraction film is affixed on the upper surface of the 1st translucent layer 110, and the upper surface of this light extraction film may comprise the light extraction surface d.

The light emitting element further includes a translucent first electrode 40 disposed between the organic functional layer 50 and the first translucent layer 110, and a second electrode facing the first electrode 40 with the organic functional layer 50 interposed therebetween. Electrode 60. That is, the first electrode 40 is disposed on one surface side of the organic functional layer 50, and the second electrode 60 is disposed on the other surface side of the organic functional layer 50.

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 Ag, Au, or 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. However, the second electrode 60 may be a transparent electrode made of a metal oxide conductor such as ITO or IZO, and a light reflecting layer (not shown) may be provided below the second electrode 60.

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 first light transmissive layer 110, the second light transmissive layer 120, the first electrode 40, and the organic functional layer 50 all transmit at least part of the light emitted from the light emitting layer of the organic functional layer 50. Part of the light emitted from the light emitting layer is emitted (extracted) from the light extraction surface d of the first light transmitting layer 110 to the outside of the light emitting element (that is, the light emission space 200).

The refractive index of the first light transmissive 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 transmissive layer 110 is made of, for example, a dielectric material. The light transmitting layer 110 is made of, for example, an epoxy resin having a refractive index of about 1.8. Alternatively, the first light transmissive layer 110 may be made of a high refractive index material containing nanoparticles using BaTiO ₃ , a high refractive index nanocomposite thin film, or the like. The first light transmissive layer 110 may be made of the same material as that of the organic functional layer 50. A thin film barrier film made of SiO ₂ or the like that suppresses the influence on the organic material may be formed between the first light transmitting layer 110 and the first electrode 40.

The second light transmitting layer 120 is made of, for example, porous silica. In the case of this embodiment, for example, the entire second light transmitting layer 120 is an inclined portion. The inclined portion is formed in a flat film shape, for example, and is inclined (inclined at an angle of, for example, 45 °) with respect to the organic functional layer 50. Note that the lower surface and the upper surface of the inclined portion are inclined in the same direction with respect to the light emitting layer, for example. Moreover, it is preferable that the lower surface and upper surface of an inclination part are mutually parallel. In this case, the light incident on the inclined portion is emitted from the inclined portion to the first light transmitting layer 110 at the same angle as the incident portion. However, the lower surface and the upper surface of the inclined portion may be inclined in directions opposite to each other with respect to the light emitting layer.

The layer thickness (film thickness) of the second light transmitting layer 120 is thicker than the wavelength of light emitted by the light emitting layer. When the layer thickness of the second light transmissive layer 120 is less than this wavelength, substantially about 100 nm or less, the evanescent light passes through the second light transmissive layer 120 and returns to the propagating light in the first light transmissive layer 110. It becomes difficult to totally reflect light at the interface between the second light transmitting layer 120 and the first light transmitting layer 110. By making the thickness of the second light transmissive layer 120 thicker than this wavelength, light can be totally reflected at the interface between the second light transmissive layer 120 and the first light transmissive layer 110. The layer thickness of the second light transmitting layer 120 is preferably sufficiently larger than the wavelength of light emitted by the light emitting layer (for example, 1 μm or more).

In addition, the minimum value of the dimension of the inclined part when the inclined part is viewed in the direction perpendicular to the inclined part and the interval (cycle) between the inclined parts arranged adjacent to each other when forming a plurality of inclined parts are also provided. , Larger than the wavelength of light emitted by the light emitting layer. These minimum values are also preferably sufficiently larger than the wavelength of light emitted by the light emitting layer (for example, 1 μm or more).

Note that the surface (lower surface) of the first light transmitting layer 110 on the organic functional layer 50 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.

The first light transmissive layer 110 is configured, for example, by curing a resin material with at least one of ultraviolet rays and heat. In addition, the 1st light transmission layer 110 is divided and formed in the part above the 2nd light transmission layer 120, and the part below the 2nd light transmission layer 120 like the Example mentioned later. Can do. For example, after forming a portion of the first light transmissive layer 110 above the second light transmissive layer 120, the second light transmissive layer 120 is formed on the lower surface of the upper portion, and then the second light transmissive layer. A lower portion of the first light transmissive layer 110 than the second light transmissive layer 120 is formed so as to cover 120. Accordingly, the second light transmissive layer 120 can be embedded in the first light transmissive layer 110.

The first electrode 40 is configured, for example, by sputtering a metal oxide conductor such as ITO or IZO on the lower surface of the first light transmitting layer 110. Furthermore, a partition wall is formed on the lower surface of the first electrode 40 as necessary. The organic functional layer 50 is configured by evaporating or applying an organic material including a light emitting layer between partition walls, for example. The second electrode 60 is configured by evaporating a metal material on the lower surface of the organic functional layer 50.

Next, the operation will be described.

The refractive index of the second light transmitting layer 120 is lower than the refractive index of the first light transmitting layer 110. For this reason, out of the light reaching the interface between the second light-transmitting layer 120 and the first light-transmitting layer 110, light having an angle greater than the critical angle at the interface is totally reflected at the interface. On the other hand, of the light reaching the interface, light having an angle less than the critical angle at the interface is transmitted through the second light transmitting layer 120 and is incident on the first light transmitting layer 110 again.

A light ray L11 illustrated in FIG. 2 travels through the first light-transmitting layer 110 and travels toward the lower surface of the second light-transmitting layer 120 (the surface on the light-emitting layer side) and the lower surface of the second light-transmitting layer 120. The light has an angle less than the critical angle at the interface with the first light transmissive layer 110. As shown in FIG. 2, is the light ray L11 transmitted through the second light transmissive layer 120 and again incident on the first light transmissive layer 110, and then emitted from the light extraction surface d to the outside (light emission space 200)? Alternatively, the light is totally reflected at the interface between the first light transmissive layer 110 and the light emission space 200. That is, the second light transmissive layer 120 does not substantially affect the extraction efficiency of the light beam L11.

On the other hand, the light ray L12 shown in FIG. 2 travels through the first light transmissive layer 110 and out of the second light transmissive layer 120 out of the light traveling toward the upper surface (the surface on the light extraction side) of the second light transmissive layer 120. The light has an angle greater than or equal to the critical angle at the interface between the upper surface and the first light transmissive layer 110. As shown in FIG. 2, the light L <b> 12 is totally reflected on the upper surface of the second light transmissive layer 120, so that its traveling direction is converted upward. For this reason, the light extraction surface d is reflected on the second light transmission layer 120 by reflecting a part of the light that is not emitted from the light extraction surface d at an angle before entering the second light transmission layer 120. Can be emitted to the outside. That is, the second light transmissive layer 120 plays a role of improving the extraction efficiency of the light beam L12. Further, the light totally reflected by the light extraction surface d is also totally reflected by the second light transmissive layer 120 and has an angle if it is not less than the critical angle at the interface between the first light transmissive layer 110 and the second light transmissive layer 120. As a result of the change, part of the light can be extracted to the outside.

Therefore, the light extraction efficiency of the light emitting element can be improved by the presence of the second light transmissive layer 120.

Next, an example of the layer structure of the organic functional layer 50 will be described.

FIG. 3 is a cross-sectional 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. 3, 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 element emits light in a single light emission color such as white.

The light emitting layer 53 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. 4 is a cross-sectional view 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 elements

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

According to the embodiment as described above, the light emitting element includes the first light transmitting layer 110 and the second light transmitting layer 120 embedded in the first light transmitting layer 110 having a refractive index lower than that of the first light transmitting layer. And at least a part of the second light transmitting layer 120 is an inclined portion inclined with respect to the light emitting layer. The surface on the organic functional layer 50 side and the surface on the light extraction side in the inclined portion are inclined with respect to the light emitting layer. The surface on the organic functional layer 50 side and the surface on the light extraction side in the inclined portion are in contact with the first light transmissive layer 110. Thereby, a part of the light reaching the second light transmitting layer 120 can be transmitted through the second light transmitting layer 120 and the other part can be totally reflected by the second light transmitting layer 120. Of the light totally reflected by the light extraction surface d, those having a critical angle or more at the interface between the first light transmitting layer 110 and the second light transmitting layer 120 are also totally reflected by the second light transmitting layer 120 and the angle. As a result of the change, a part of the light can be extracted to the outside. That is, the light extraction efficiency of the light emitting element can be improved by utilizing the reflection of light at the second light transmissive layer 120. Here, the light extraction efficiency can be improved regardless of the wavelength of light from the light emitting layer. Therefore, when the light-emitting element is an organic EL element, light emission characteristics in a broad wavelength range that is one of the characteristics of the organic EL element can be sufficiently obtained.

(Example 1)
FIG. 5 is a cross-sectional view of the light emitting device according to this example. The light-emitting element according to this example is different from the light-emitting element according to the above-described embodiment in the points described below, and is otherwise configured in the same manner as the light-emitting element according to the above-described embodiment.

In the case of the present embodiment, the second light transmitting layer 120 has a plurality of inclined portions inclined with respect to the light emitting layer in the same direction. FIG. 5 shows two

inclined portions

120a and 120b. Each

inclination part

120a, 120b is the same as that of the 2nd light transmission layer 120 in said embodiment. Note that the upper surface and the lower surface of the inclined portion 120a are inclined in the same direction with respect to the light emitting layer. Similarly, the upper surface and the lower surface of the inclined portion 120b are inclined in the same direction with respect to the light emitting layer.

The inclination angles of the

inclined portions

120a and 120b can be set to the same angle, for example. The

inclined portions

120a and 120b are spaced apart from each other at a predetermined interval (for example, a constant interval) in a direction parallel to the light emitting layer, and are disposed in parallel to each other.

As shown in FIG. 5, in the case of the present embodiment, the light beams L11 and L12 operate in the same manner as in the above embodiment.

The light ray L13 shown in FIG. 5 travels through the first light transmitting layer 110 and travels toward the lower surface of the one inclined portion 120a (the surface on the light emitting layer side), and the lower surface of the inclined portion 120a and the first light transmitting light. The light has an angle greater than the critical angle at the interface with the layer 110. As shown in FIG. 5, the light ray L13 is totally reflected on the lower surface of the inclined portion 120a. Thereafter, as shown in FIG. 5, a part of the light beam L13 is totally reflected on the upper surface of the other inclined portion 120b, so that its traveling direction is converted upward. For this reason, the extraction efficiency of the light beam L13 can be improved by the cooperation of the

inclined portions

120a and 120b.

According to this example, the same effect as the above embodiment can be obtained. In the case of this embodiment, the light emitting element has a plurality of inclined portions (

inclined portions

120a, 120b, etc.) inclined in the same direction with respect to the light emitting layer. The light extraction efficiency can be improved more than the form.

In the present embodiment, the second light transmitting layer 120 may include a plurality of inclined portions inclined with respect to the light emitting layer at different inclination angles. As a result, the extraction efficiency can be improved with respect to light having various angles. For example, the inclination directions of the inclined portions with respect to the light emitting layer are the same as each other, but the inclination angles (the absolute values of the inclination angles) of these inclined portions are different from each other. Alternatively, the inclination directions of the inclined portions with respect to the light emitting layer are different from each other, and the inclination angles of the inclined portions are different from each other.

(Example 2)
FIG. 6 is a cross-sectional view of the light emitting device according to this example. The light-emitting element according to this example is different from the light-emitting element according to the above-described embodiment in the points described below, and is otherwise configured in the same manner as the light-emitting element according to the above-described embodiment.

In the case of the present embodiment, the second light transmitting layer 120 has a plurality of inclined portions inclined with respect to the light emitting layer in opposite directions. FIG. 6 shows two

inclined portions

120a and 120b. Each

inclination part

120a, 120b is the same as that of the 2nd light transmission layer 120 in said embodiment. Note that the upper surface (surface on the light extraction side) and the lower surface (surface on the organic functional layer side) of the inclined portion 120a are inclined in the same direction with respect to the light emitting layer. Similarly, the upper surface (surface on the light extraction side) and the lower surface (surface on the organic functional layer side) of the inclined portion 120b are inclined in the same direction with respect to the light emitting layer.

The absolute value of the inclination angle of the

inclined portions

120a and 120b with respect to the light emitting layer can be set to the same value, for example. The

inclined portions

120a and 120b are separated from each other at a predetermined interval (for example, a constant interval) in a direction parallel to the light emitting layer, for example.

As shown in FIG. 6, in the case of the present embodiment, the light beams L11 and L12 operate in the same manner as in the above embodiment. In addition, the light beam L14 illustrated in FIG. 6 is light that takes a path that is plane-symmetrical (plane-symmetrical with respect to a plane orthogonal to the light-emitting layer) with respect to the light beam L12. The light beam L14 also has the same operation as the light beam L12 (a plane-symmetric operation with respect to a plane orthogonal to the light emitting layer). In the case of this example, the extraction efficiency of the light beam L14 can be improved as compared with the above embodiment.

inclined portions

120a, 120b, etc.) inclined in directions opposite to each other with respect to the light emitting layer. The light extraction efficiency can be improved more than the form.

Note that, also in the present embodiment, the second light transmitting layer 120 may include a plurality of inclined portions inclined at different inclination angles with respect to the light emitting layer. That is, the inclination directions of the inclined portions with respect to the light emitting layer are opposite to each other, and the inclination angles (the absolute values of the inclination angles) of the inclined portions are different from each other. As a result, the extraction efficiency can be improved with respect to light having various angles.

(Example 3)
FIG. 7 is a cross-sectional view of the light emitting device according to this example. FIG. 8 is a perspective view of a part of the second light transmitting layer 120 of the light emitting device according to this embodiment. Each of FIGS. 9A to 9C is a cross-sectional view illustrating paths through which light generated in the light emitting layer is emitted to the outside in the light emitting device according to this example. The light-emitting element according to this example is different from the light-emitting element according to the above-described embodiment in the points described below, and is otherwise configured in the same manner as the light-emitting element according to the above-described embodiment.

As shown in FIG. 7, in the case of the present embodiment, the second light transmitting layer 120 includes a plurality of inclined portions inclined with respect to the light emitting layer in directions opposite to each other. The second light transmissive layer 120 includes a plurality of inclined portions that are inclined with respect to the light emitting layer in the same direction. In each of the inclined portions, the lower surface and the upper surface are inclined in the same direction with respect to the light emitting layer.

Further, the second light-transmitting layer 120 is disposed along a first inclined portion (for example, along surfaces A0 to A3 described later) that is inclined with respect to the light emitting layer around a first axis extending in the first direction in a plan view. Tilted with respect to the light emitting layer around a second axis that intersects (for example, perpendicular to) the first direction in plan view, and the tilted portions disposed along the planes C0 to C3 described later). Second inclined portions (for example, inclined portions respectively disposed along the surfaces B0 and B1 described later, or inclined portions respectively disposed along the surfaces D0 and D1 described later).

As shown in FIG. 8, the second light transmitting layer 120 includes each side surface of the truncated pyramid whose cross-sectional area decreases toward either the light extraction side or the light emitting layer side, and the same number of side surfaces as the truncated pyramid. And each side surface of the pyramid having a lower base (bottom surface) coinciding with the upper base of the truncated pyramid and having a cross-sectional area that decreases toward either the light extraction side or the light emitting layer side. A plurality of units 121 each composed of an inclined portion are arranged in a direction parallel to the light emitting layer.

For example, the height of the pyramid that defines the shape of the unit 121 (the distance from the lower base to the upper base) and the height of the pyramid (the distance from the lower base (bottom surface) to the apex) are equal to each other.

FIG. 8 shows two units 121 of the second light transmissive layer 120.
Among these units, the front unit 121 includes four inclined portions arranged along four side surfaces A0, B0, C1, and D1 of the quadrangular pyramid whose cross-sectional area decreases toward the light extraction side, and the quadrangular pyramid. Four inclined portions respectively disposed along four side faces C0, D0, A1, and B1 of a quadrangular pyramid having a lower base that coincides with the upper base of the quadrangular pyramid and having a cross-sectional area that decreases toward the light emitting layer. A total of eight ramps are included.
Here, the quadrangular frustum and the quadrangular pyramid that define the shape of the unit 121 are rectangular in plan view. More specifically, the quadrangular pyramid is a regular quadrangular pyramid, and the quadrangular pyramid is a regular quadrangular pyramid.

The rear unit 121 is configured in the same manner as the front unit 121. Of the four side surfaces of the truncated pyramid that defines the shape of the back unit 121, the side surface corresponding to the side surface A0 of the front unit 121 is referred to as a side surface A2, and the side surface corresponding to the side surface C1 of the front unit 121 is the side surface C3. Called. Of the four sides of the quadrangular pyramid that defines the shape of the back unit 121, the side corresponding to the side C0 of the front unit 121 is referred to as side C2, and the side corresponding to the side A1 of the front unit 121 is the side. This is referred to as A3.

In addition, the plurality of units 121 are arranged without a gap so that, for example, one side of the lower base of the truncated pyramid defining the shape of each other coincides with each other.

The first light transmissive layer 110 includes a first portion 111 located on the upper side (light extraction side) of the second light transmissive layer 120 and a first portion located on the lower side (light emitting layer side) of the second light transmissive layer 120. 2 parts 112. The refractive index of the second light transmitting layer 120 is lower than the refractive index of the first portion 111 and lower than the refractive index of the second portion 112. Note that the refractive index of the first portion 111 and the refractive index of the second portion 112 may be equal to each other or may be different from each other.

A barrier film 70 is formed between the first light transmissive layer 110 and the first electrode 40. The barrier film 70 is made of, for example, a SiO ₂ thin film or graphene.

Further, a light extraction film 130 having an uneven structure (not shown) on the surface (upper surface) is attached to the upper surface of the first light transmissive layer 110, and the upper surface of the light extraction film 130 forms a light extraction surface d. ing.

In the case of the present embodiment, it is assumed that each of the truncated pyramid defining the shape of each unit 121 and the side surfaces of the pyramid are inclined so that the absolute value of the angle with respect to the light emitting layer is 45 degrees. Here, the absolute value of the angle with respect to the light emitting layer being 45 degrees means that the angle with respect to the light emitting layer is 45 degrees or 135 degrees (−45 degrees).

Here, FIG. 7 shows a quadrangular pyramid apex P1 that defines the shape of one unit 121, and a quadrangular pyramid apex P2 that defines the shape of the other unit 121, out of two units 121 arranged in a row. It is sectional drawing when a light emitting element is cut | disconnected in the surface which passes and is orthogonal to a light emitting layer. Each of FIGS. 9A to 9C shows the same cross section as FIG.

Hereinafter, with reference to FIGS. 9A to 9C, the light passing through the cross section shown in FIG. 7 has an upward component (the angle with respect to the light emitting layer is larger than 0 degree and larger than 180 degrees). A path of light incident on an inclined portion (for example, the inclined portion 120c along the plane C1 in FIGS. 9A to 9C) having an angle of 135 degrees with respect to the light emitting layer will be described. For convenience, the description will be made assuming that the minimum unit of the light angle is 0.1 degree.

Here, it is assumed that the refractive index of the first light transmitting layer 110 is 1.8. The second light transmissive layer 120 is made of, for example, porous silica and has a refractive index of about 1.27 to 1.3. In this case, the critical angle at the interface between the second light transmitting layer 120 and the first light transmitting layer 110 is 46.2 degrees. Moreover, the layer thickness (film thickness) of the 2nd translucent layer 120 shall be fixed, and shall be 2 micrometers. In addition, the height of the quadrangular frustum defining the shape of the unit 121 and the quadrangular pyramid is 20 μm.

Of the light emitted from the light emitting layer, light having an upward component passes through the first electrode 40, the barrier film 70, and the second portion 112 of the first light transmitting layer 110 in this order, and the second light transmitting layer. It reaches 120 inclined portions 120c.

Among these, light having an inclination angle θ with respect to the light emitting layer of 1 degree or more and 91.1 degrees or less (light rays L21 and L22 shown in FIG. 9A) passes through the inclined part 120c and passes through the inclined part 120c. The light enters the first portion 111. This is because the inclination angle of the inclined portion 120c is 135 degrees as described above. For this reason, the incident angle of the light having the inclination angle θ of 1 to 91.1 degrees with respect to the inclined portion 120c is (135-90-91.1) to (135-90-1) degrees, that is, −46. This is because any absolute value is less than the critical angle (46.2 degrees) from 1 degree to 44 degrees.
A part of the light transmitted through the inclined portion 120c, that is, light having an inclination angle θ of 45 degrees or more and 91.1 degrees or less, such as the light beam L21 shown in FIG. 9A, reaches the inclined section other than the inclined section 120c. Without being transmitted, the light passes through the first portion 111 and the light extraction film 130 in this order and is emitted to the light emission space 200.
Further, another part of the light incident on the inclined portion 120c, that is, light having an inclination angle θ of 1.2 degrees or more and 44.9 degrees or less like the light ray L22 shown in FIG. After coming out of the slope, it reaches an inclined portion 120d (an inclined portion along the plane A2) that is obliquely opposed to the inclined portion 120c and is adjacent to the inclined portion 120c. And the advancing direction is converted upwards by totally reflecting in the inclination part 120d. Specifically, the inclination angle θ is converted to 45.1 degrees or more and 88.8 degrees or less. For this reason, the light then passes through the first portion 111 and the light extraction film 130 in this order, and is emitted to the light emission space 200.

Further, light having an inclination angle θ of 91.2 degrees or more and 134.9 degrees or less (light rays L23 and L24 shown in FIG. 9B) is totally reflected on the lower surface of the inclined portion 120c. This is because the incident angle of the light having the inclination angle θ of 91.2 degrees or more and 134.9 degrees or less to the inclined portion 120c is (135-90-134.9) degrees or more and (135-90-91.2) degrees or less. That is, it is -89.9 degrees or more and -46.2 degrees or less, and any absolute value becomes the critical angle (46.2 degrees) or more. Light having an inclination angle θ of 91.2 degrees or more and 134.9 degrees or less is converted to an inclination angle θ of 135.1 degrees or more and 178.8 degrees or less by being totally reflected by the lower surface of the inclined portion 120c.
The light after being totally reflected by the inclined portion 120c passes through the inclined portion 120g adjacent to the inclined portion 120c (adjacent to the opposite side to the inclined portion 120d) and enters the first portion 111.
Among these, a part of the light (the light beam L23 shown in FIG. 9B, etc.) is then transmitted through the first portion 111 and the light extraction film 130 in this order, and is emitted to the light emission space 200.
Further, another part of light (such as the light beam L24 shown in FIG. 9B) is then adjacent to the inclined portion 120g (adjacent to the side opposite to the inclined portion 120c) on the upper surface of the inclined portion 120h. After total reflection, the light is emitted to the light emission space 200.

Note that light having an inclination angle θ of 135 degrees (such as the light beam L25 shown in FIG. 9C) does not enter the inclined portion 120c but is transmitted to the light emitting space 200 after passing through the inclined portion 120g.

In the above, compared with the case where the 2nd light transmission layer 120 does not exist, the taking-out efficiency of the light ray L22 shown to Fig.9 (a) improves.

Similarly, with respect to light other than the light passing through the cross section shown in FIG. 7, any one of the inclined portions of the second light transmitting layer 120 (inclined portions along the planes B0, B1, D0, D1, etc.). A part of the light is reflected from the surface of the light-emitting element or is transmitted through one of the inclined portions. At this time, the second light-transmitting layer 120 contributes to the improvement of the light extraction efficiency by a mechanism similar to the mechanism described in FIGS. 9A to 9C.

When the inclination angle of the inclined part is smaller than 45 ° (shallow), a part of the light is totally reflected toward the second electrode 60 side by the second light-transmitting layer 120 and then applied to the second electrode. Then, the light is reflected to the second light transmitting layer 120 side. As a result, among the inclined portions of the second light-transmitting layer 120, it is possible to hit the inclined portion in a direction different from the inclined portion where the part of light hits before. Thereby, a part of the part of the light can be extracted from the light emitting element by the same mechanism as described above.

Also in this embodiment, at least a part of the second light transmitting layer 120 is an inclined portion inclined with respect to the light emitting layer. The surface on the organic functional layer 50 side and the surface on the light extraction side in the inclined portion are in contact with the first light transmissive layer 110. For this reason, the effect similar to said embodiment is acquired.

Further, the second light transmitting layer 120 has a plurality of inclined portions inclined with respect to the light emitting layer in the same direction. For this reason, the effect similar to said Example 1 is acquired.

Further, the second light transmitting layer 120 has a plurality of inclined portions inclined with respect to the light emitting layer in opposite directions. For this reason, the same effect as in the second embodiment can be obtained.

In addition, the second light transmitting layer 120 intersects the first inclined portion inclined with respect to the light emitting layer around the first axis extending in the first direction in a plan view (for example, the first direction in the plan view (for example, And a second inclined portion inclined with respect to the light emitting layer around a second axis that is orthogonal to each other. Therefore, the extraction efficiency of light traveling in various directions in plan view can be improved.

The second light transmitting layer 120 has each side surface of the truncated pyramid whose cross-sectional area is reduced toward either the light extraction side or the light emitting layer side, and the same number of side surfaces as the truncated pyramid. Each of the side surfaces of the pyramid having a lower base coinciding with the upper base of the pyramid frustum and reducing the cross-sectional area toward either the light extraction side or the light emitting layer side, and each of the inclined portions disposed along the side surfaces. A plurality of units 121 are arranged in a direction parallel to the light emitting layer. For this reason, in the case of the present embodiment, the second light transmissive layer 120 includes inclined portions having more directions as compared with the first embodiment. Thereby, the extraction efficiency of light in various directions can be improved as compared with the first embodiment. Similarly, in the case of the present embodiment, the second light transmissive layer 120 includes inclined portions having more directions as compared to the second embodiment. Thereby, the extraction efficiency of light in various directions can be improved as compared with the second embodiment. For example, the effect described above with reference to FIG. 9 or an equivalent effect can be obtained.

Also, the height of the truncated pyramid defining the shape of the unit 121 is equal to the height of the pyramid. Thereby, compared with the case where the height of the truncated pyramid and the height of the pyramid are different from each other, the total amount of the inclined portion (total amount of the inclined portion) in the region occupied by the unit 121 (region in the thickness direction of the light emitting element) is increased. can do. Therefore, the light extraction efficiency can be increased more efficiently by the second light transmitting layer 120 disposed in a limited region (region in the thickness direction of the light emitting element).

Further, since the truncated pyramid that defines the shape of the unit 121 is a rectangular truncated pyramid having a rectangular shape in plan view, a plurality of units 121 can be arranged with no gap therebetween. Thereby, more inclined parts can be arrange | positioned in the limited area | region.

Specifically, the plurality of units 121 can be arranged side by side without a gap so that the sides of the lower base of the truncated pyramid defining the shape of each other coincide with each other. By doing so, it is possible to regularly arrange a plurality of inclined portions, so that the light extraction efficiency can be improved uniformly in each region in the plane of the light emitting element.

Note that even when the truncated pyramid that defines the shape of the unit 121 is a triangular truncated pyramid, there are cases where a plurality of units 121 can be arranged without gaps (when the bottom surface is an equilateral triangle, a right isosceles triangle, or the like).
Further, the truncated pyramid defining the shape of the unit 121 may be a polygonal truncated pyramid having a number of side faces equal to or larger than a pentagonal truncated pyramid. Further, the truncated pyramid that defines the shape of the unit 121 may be a truncated pyramid having a plane shape other than a rectangle.
In these cases, the case where the first axis and the second axis intersect with each other in a relationship other than orthogonal is included.

In the present embodiment, each unit 121 may be turned upside down from that shown in FIG.
Further, the vertical direction of each unit 121 may be different (can be set individually). In other words, the unit 121 in the direction shown in FIG. 8 and the unit 121 that is upside down from FIG. 8 may be mixed. For example, the units 121 whose tops and bottoms are inverted in this manner may be alternately arranged (arranged in a staggered manner in a plan view).

Example 4
FIG. 10A is a plan view of the light emitting device according to this example, and FIG. 10B is a cross-sectional view taken along the line CC in FIG. 10A. In this example, an example of a more specific configuration of the light emitting device according to Example 3 will be described. In FIGS. 10B and 10A, the upper and lower sides are inverted with respect to FIG.

The first electrode 40 constitutes an anode. The plurality of first electrodes 40 each extend in a band shape in the Y direction parallel to the light emitting layer. Adjacent first electrodes 40 are parallel to the light emitting layer and spaced apart from each other in the X direction perpendicular 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. In this insulating film, a plurality of stripe-shaped openings each extending in the Y direction are formed. 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 Ag, Au, or Al 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, green, and blue light are arbitrarily mixed from the light extraction surface d. In this way, light that is recognized as a single emission color (for example, white) is emitted.

Here, a method of forming the first light transmissive layer 110 and the second light transmissive layer 120 will be described.

First, after the first portion 111 of the first light transmitting layer 110 is formed with an organic material or the like, an uneven shape having the same shape as the unit 120 (FIG. 8) is formed on one surface of the first portion 111. The uneven shape can be formed by processing the surface of the first portion 111 using a known surface processing technique such as cutting and polishing, laser processing, chemical etching, or thermal imprinting. Note that, as in other embodiments described later, the first portion 111 of the first light-transmissive layer 110 may be formed of glass or the like.

Next, the second light transmitting layer 120 is formed by vapor deposition or sputtering so as to cover the uneven shape of one surface of the first portion 111. Accordingly, the second light transmitting layer 120 is formed as a three-dimensional film reflecting the uneven shape of the first portion 111.

Next, the second portion 112 is formed of an organic material or the like so as to cover the second light transmitting layer 120. Thereby, it is possible to realize a structure in which the second light transmissive layer 120 is embedded in the first light transmissive layer 110.

In addition, after forming the second portion 112 in which the concavo-convex shape that meshes with the concavo-convex shape of the first portion 111 is formed on one surface in advance, after the second light-transmitting layer 120 is formed, the second portion 112 is changed to the second portion 112. You may affix on the translucent layer 120. FIG.

Also, the second light transmissive layer 120 may be formed in advance separately from the first portion 111, and the second light transmissive layer 120 may be attached to the first portion 111.

Also in this embodiment, the same effect as in the third embodiment can be obtained.

(Example 5)
FIG. 11A is a cross-sectional view of the light emitting device according to this example, and FIG. 11B is a perspective view of the second light transmitting layer 120 of the light emitting device according to this example. The light emitting device according to this example is different from the light emitting device according to Example 3 (FIGS. 7 and 8) in the points described below, and is otherwise the same as the light emitting device according to Example 3. It is configured.

As shown in FIG. 11B, in the case of the present embodiment, the second light-transmitting layer 120 includes each side surface of the truncated pyramid whose cross-sectional area decreases toward either the light extraction side or the light emitting layer side. Second side having the same number of side surfaces as the truncated pyramid and having a lower base coinciding with the upper base of the truncated pyramid and having a cross-sectional area that is reduced toward either the light extraction side or the light emitting layer side. Each unit 121 is formed by arranging a plurality of units 121 each having a slope portion arranged along each side surface of the truncated pyramid in a direction parallel to the light emitting layer. Therefore, each unit 121 is formed with a polygonal opening 125 that penetrates the second light transmitting layer 120 from the light emitting layer side to the light extraction side.

In the case of the present embodiment as well, similarly to the third embodiment, the second light transmitting layer 120 naturally includes a plurality of inclined portions inclined with respect to the light emitting layer in opposite directions and emits light in the same direction. A plurality of inclined portions inclined with respect to the layer are included.

Further, in the case of this example as well, as in Example 3, the second light-transmitting layer 120 is naturally the first inclined with respect to the light emitting layer around the first axis extending in the first direction in plan view. And an inclined portion and a second inclined portion that is inclined with respect to the light emitting layer around a second axis that intersects (specifically, is orthogonal to) the first direction in plan view.

For example, the height of the truncated pyramid that defines the shape of the unit 121 (the distance from the lower base to the upper base) and the height of the second truncated pyramid (the distance from the lower base to the upper base) are equal to each other.

FIG. 11B shows one unit 121 of the second light transmissive layer 120.
The unit 121 includes four inclined portions arranged along four side surfaces A0, B0, C1, and D1 of the quadrangular pyramid whose cross-sectional area is reduced toward the light extraction side, and an upper base of the quadrangular pyramid. And four inclined portions respectively disposed along the four side surfaces C0, D0, A1, and B1 of the second quadrangular pyramid having a lower base that coincides with the light emitting layer side and whose cross-sectional area decreases toward the light emitting layer side. A total of eight ramps are included. For this reason, the unit 121 is formed with a rectangular opening 125 that penetrates the second light transmitting layer 120 from the light emitting layer side to the light extraction side. Note that the first portion 111 and the second portion 112 of the first light transmitting layer 110 are in contact with each other through the opening 125. Further, the interface between the first portion 111 and the second portion 112 is formed in parallel to the light emitting layer, for example.
Here, the quadrangular frustum and the second quadrangular frustum that define the shape of the unit 121 have a rectangular shape in plan view. More specifically, the square frustum and the second square frustum are regular square frustums.
In addition, when the length of one side of the opening 125 is L (see FIG. 11A), the value of L is 0 in the third embodiment (FIGS. 7 and 8).

In the case of the present embodiment, by using a mask or the like, the second light-transmitting layer 120 is selectively formed in a region other than the opening 125 on the lower surface of the first portion 111 to thereby form the second light-transmitting light having the opening 125. Layer 120 can be formed. Alternatively, the second light-transmitting layer 120 having the opening 125 may be formed by forming the second light-transmitting layer 120 on the entire lower surface of the first portion 111 and then partially etching the second light-transmitting layer 120. Can be formed.

Further, as in the third embodiment, the plurality of units 121 are arranged without a gap so that one side of the bottom base of the truncated pyramid defining the shape of each other coincides with each other.

In the present embodiment, the second light transmitting layer 120 has each side surface of the truncated pyramid whose cross-sectional area decreases toward either the light extraction side or the light emitting layer side, and the same number of side surfaces as the truncated pyramid. And each side surface of the second truncated pyramid that has a lower base that coincides with the upper base of the truncated pyramid and whose cross-sectional area decreases toward the other of the light extraction side and the light emitting layer side, respectively. It is configured by arranging a plurality of units 121 each having an inclined portion arranged in a direction parallel to the light emitting layer. The number and arrangement of the inclined portions included in each unit 121 are the same as those in the third embodiment. For this reason, the same effect as that of the third embodiment can be obtained by this embodiment.

Also, the height of the truncated pyramid that defines the shape of the unit 121 is equal to the height of the second truncated pyramid. As a result, more inclined portions can be formed in the region occupied by the unit 121 (region in the thickness direction of the light emitting element) than when the height of the truncated pyramid and the height of the second truncated pyramid are different from each other. it can.

According to the present embodiment, the same effects as those of the above-described third embodiment can be obtained in other respects.

In this embodiment, as in the third embodiment, each unit 121 may be turned upside down from that shown in FIG. Similarly to the third embodiment, the vertical direction of each unit 121 may be different (set individually).

(Example 6)
FIG. 12 is a cross-sectional view of the light emitting device according to this example. The light-emitting element according to this example is different from any of the light-emitting elements described above in the configuration described below in the configuration of the first light-transmitting layer 110. The configuration is the same as that of the light emitting element.

In the case of the present embodiment, the first light transmissive layer 110 includes the light transmissive substrate 140 disposed on the light extraction side with respect to the second light transmissive layer 120. The translucent substrate 140 is formed in a flat plate shape with a translucent material such as glass or resin. When the translucent substrate 140 is made of glass, the refractive index of the translucent substrate 140 is, for example, about 1.5. The translucent substrate 140 may be a translucent film. The refractive index of the translucent substrate 140 is lower than the refractive index of at least the second portion 112 of the first translucent layer 110.

The configuration of the second light transmissive layer 120 may be any of the above configurations. As an example, FIG. 12 shows an example in which the configuration of the fifth embodiment is adopted as the configuration of the second light transmitting layer 120. As shown in FIG. 12, the upper end of the second light transmissive layer 120 (the upper end of the unit 121) and the lower surface of the light transmissive substrate 140 may be in contact with each other, or the upper end of the second light transmissive layer 120 may be The first portion 111 may be interposed between the translucent substrate 140.

In the case of the present embodiment, the structure from the first portion 111 to the second electrode 60 is sequentially formed on the translucent substrate 140 (on the lower surface in FIG. 12) using the previously formed translucent substrate 140 as a support substrate. By forming, a light emitting element can be manufactured.

Here, the refractive index of the portion of the first light transmitting layer 110 between the second light transmitting layer 120 and the light transmitting substrate 140 (that is, the first portion 111) is made equal to the refractive index of the light transmitting substrate 140. be able to. By doing in this way, the reflection of the light etc. between the part between the 2nd translucent layer 120 and the translucent board | substrate 140 in the 1st translucent layer 110, and the translucent board | substrate 140 can be suppressed. . As a result, a region where total reflection of light occurs is located between the second portion 112 of the first light transmissive layer 110 and the light transmissive substrate 140 and is a region parallel to the light emitting layer. Since the area of this region is smaller than the contact area between the first portion 111 and the translucent substrate 140, an improvement in light extraction efficiency can be expected.

In the case of this example, since the first light-transmitting layer is configured to include the light-transmitting substrate 140, the rigidity (mechanical strength) of the light-emitting element can be improved. In addition, since the light-emitting element can be manufactured using the light-transmitting substrate 140 as a support substrate, the light-emitting element can be easily manufactured.

(Example 7)
FIG. 13 is a cross-sectional view of the light emitting device according to this example. The light emitting device according to this example is different from the light emitting device according to Example 6 described above (FIG. 12) in the points described below, and is otherwise configured in the same manner as the light emitting device according to Example 6. Yes.

In Example 6 described above, an example in which the refractive index of the portion of the first light transmissive layer 110 between the second light transmissive layer 120 and the light transmissive substrate 140 is equal to the refractive index of the light transmissive substrate 140 has been described. .

On the other hand, in the case of the present embodiment, the portion of the first light transmissive layer 110 on the light extraction side with respect to the second light transmissive layer 120 is composed of the light transmissive substrate 140. The light transmissive substrate 140 is in contact with the light extraction side surface (the upper surface in FIG. 13) of the second light transmissive layer 120. In other words, the first portion 111 is configured by the translucent substrate 140.
According to the present embodiment, since the first portion 111 does not need to be configured by two portions, the configuration of the light emitting element can be simplified as compared with the above-described Embodiment 6.

(Example 8)
FIG. 14A is a cross-sectional view of the light emitting device according to this example, and FIG. 14B is a perspective view of the second light transmitting layer 120 of the light emitting device according to this example. The light-emitting element according to this example is different from the light-emitting element according to the above-described embodiment in the points described below, and is otherwise configured in the same manner as the light-emitting element according to the above-described embodiment.

As shown in FIG. 14, in the case of the present embodiment, the second light transmitting layer 120 includes a plurality of inclined portions inclined with respect to the light emitting layer in opposite directions. The second light transmissive layer 120 includes a plurality of inclined portions that are inclined with respect to the light emitting layer in the same direction.

As shown in FIG. 14B, the second light transmitting layer 120 is configured by arranging a plurality of first units 201 and second units 202 in a direction parallel to the light emitting layer.
The 1st unit 201 consists of a slope part arranged along the 1st and 2nd slope which is two slopes of the 1st gable roof shape 221, respectively. The first gable roof shape 221 has a first axis 211 parallel to the light emitting layer as a top, and is convex toward the light extraction side or the light emitting layer side. Note that the gable roof shape means that two rectangular surfaces having the same shape and dimensions are aligned with each other and the positions of the sides having a common length are inclined with respect to each other as the axis of rotation. Thus, the two rectangular surfaces are formed so as to be diagonally opposed to each other (including a state in which they are orthogonal to each other).
In addition, the second unit 202 includes inclined portions respectively disposed along the third and fourth inclined surfaces that are the two inclined surfaces of the second gable roof shape 222. The second gable roof shape 222 has a second axis 212 that is parallel to the light emitting layer and orthogonal to the first axis 211 as a top, and is convex toward the light extraction side or the light emitting layer side. .

For this reason, also in the case of the present embodiment, the second light-transmitting layer 120 naturally has a first inclined portion inclined with respect to the light emitting layer around the first axis extending in the first direction in plan view, and in plan view. And a second inclined portion inclined with respect to the light emitting layer around a second axis that intersects (specifically, orthogonally) with respect to the first direction.

More specifically, for example, the first unit 201 and the second unit 202 are alternately arranged in the longitudinal direction of the first shaft 211, and the first unit 201 and the second unit 202 are connected to the second shaft 212. Are alternately arranged in the longitudinal direction.

More specifically, for example, the first gable roof shape 221 and the second gable roof shape 222 are convex in the same direction, and are composed of two first units 201 and two second units 202 4. The ends of the light emitting layer side or the light extraction side of the two units are in contact with each other at one point P201 in plan view. In the example of FIG. 14, the first gable roof shape 221 and the second gable roof shape 222 are convex toward the light extraction side, and four units including two first units 201 and two second units 202 are provided. The ends on the light emitting layer side are in contact with each other at a point P201. That is, a large number of first units 201 and a large number of second units 202 are arranged in a zigzag shape in a plan view without any gaps so that four units adjacent to each other are in contact with each other at one point in a plan view.

More specifically, for example, the dimension of the first unit 201 in the direction orthogonal to the light emitting layer is equal to the dimension of the second unit 202 in the direction orthogonal to the light emitting layer.

Also in this example, the absolute value of the angle of each inclined portion of the second light transmitting layer 120 with respect to the light emitting layer is, for example, 45 degrees. That is, the first inclined surface, the second inclined surface, the third inclined surface, and the fourth inclined surface are inclined at an angle of 45 degrees with respect to the light emitting layer.

The first light-transmitting layer 110 is composed of a first portion 111 and a second portion 112, the barrier film 70 is formed between the first light-transmitting layer 110 and the first electrode 40, and the first The point that the light extraction film 130 is affixed on the upper surface of the light transmissive layer 110 is the same as in the third embodiment. Further, the point that the first light transmissive layer 110 includes the light transmissive substrate 140 is the same as that in the sixth embodiment. FIG. 14 shows an example in which the first portion 111 is interposed between the upper end of the second light-transmitting layer 120 and the light-transmitting substrate 140, but the upper end of the second light-transmitting layer 120 ( The upper ends of the first unit 201 and the second unit 202) and the lower surface of the translucent substrate 140 may be in contact with each other.

The second light transmissive layer 120 has two inclined surfaces of a first gable roof shape 221 that has a first axis 211 parallel to the light emitting layer as a top and is convex toward the light extraction side or the light emitting layer side. Light extraction with the first unit 201 formed of inclined portions arranged along the first and second inclined surfaces and the second axis 212 parallel to the light emitting layer and orthogonal to the first axis 211 as the top. Of the second gable roof shape 222 convex toward the side or the light emitting layer side, and the second unit 202 composed of inclined portions respectively arranged along the third and fourth inclined surfaces which are two inclined surfaces. The plurality of layers are arranged in a direction parallel to the layer. For this reason, in the case of the present embodiment, the second light transmissive layer 120 includes inclined portions having more directions as compared with the first embodiment. Thereby, the extraction efficiency of light in various directions can be improved as compared with the first embodiment. Further, light that does not hit the second light transmissive layer 120 that forms the gable roof shape can pass directly to the first portion 111 of the first light transmissive layer 110, and the adjacent second light transmissive layer having the gable roof shape. The light is totally reflected on the upper surface of 120 and then travels toward the light extraction side. Similarly, in the case of the present embodiment, the second light transmissive layer 120 includes inclined portions having more directions as compared to the second embodiment. Thereby, the extraction efficiency of light in various directions can be improved as compared with the second embodiment.

The first unit 201 and the second unit 202 are alternately arranged in the longitudinal direction of the first shaft 211, and the first unit 201 and the second unit 202 are alternately arranged in the longitudinal direction of the second shaft 212. Has been placed. Thereby, regularity can be given to arrangement | positioning of the inclination part in the 2nd translucent layer 120. FIG. As a result, the light extraction efficiency can be improved more uniformly in each region in the plane of the light emitting element.

In addition, the first gable roof shape 221 and the second gable roof shape 222 are convex in the same direction, and the light emitting layer side in the four units including the two first units 201 and the two second units 202. Alternatively, the end portions on the light extraction side are in contact with each other at one point P201 in plan view. Thereby, while the regularity of arrangement | positioning of the inclination part in the 2nd translucent layer 120 can further be improved, the planar arrangement density of the 1st unit 201 and the 2nd unit 202 can be raised. As a result, the light extraction efficiency can be improved more uniformly in each region in the plane of the light emitting element, and the light extraction efficiency can be further increased.

Further, the dimension of the first unit 201 in the direction orthogonal to the light emitting layer is equal to the dimension of the second unit 202 in the direction orthogonal to the light emitting layer. Thereby, compared with the case where the height of the 1st unit 201 and the height of the 2nd unit 202 mutually differ, the total amount (the area | region in the thickness direction of a light emitting element) which the 2nd light transmission layer 120 occupies (the amount of inclination parts) The total area of the inclined portion) can be increased. Therefore, the light extraction efficiency can be increased more efficiently by the second light transmitting layer 120 disposed in a limited region (region in the thickness direction of the light emitting element).

In the present embodiment, the first unit 201 may be reversed upside down from that shown in FIG. Similarly, the second unit 202 may be inverted from that shown in FIG.
In addition, the vertical direction of each of the plurality of first units 201 may be individually different (the vertical direction may be set individually). Similarly, the vertical direction of each of the plurality of second units 202 may be individually different (the vertical direction may be set individually).

Example 9
FIG. 15A is a perspective view of the second light transmitting layer 120 of the light emitting device according to this example, and FIG. 15B is a cross-sectional view of the light emitting device according to Example 9. The light-emitting element according to this example is different from the light-emitting element according to the above-described embodiment in the points described below, and is otherwise configured in the same manner as the light-emitting element according to the above-described embodiment.

In the case of this example, the second light transmitting layer 120 is configured by arranging a plurality of units 340 shown in FIG. 15A in a direction parallel to the light emitting layer.
In FIG. 15 (a), the first gable roof shape 321 has a first axis 311 extending in a first direction (arrow A direction) parallel to the light emitting layer and having a predetermined length as a top, on the light extraction side. Or it is convex toward either one of the light emitting layer side. The two inclined surfaces of the first gable roof shape 321 are referred to as first and second inclined surfaces, respectively. The first and second inclined surfaces have the same shape.
The second gable roof shape 322 has the second axis 312 as the top. The second gable roof shape 322 is formed in the same shape as the first gable roof shape 321 and is convex in the same direction as the first gable roof shape 321. The second axis 312 is the first axis in the second direction (arrow B direction) parallel to the light emitting layer and orthogonal to the first direction, as much as the width of the first gable roof shape 321 in the second direction. This is the axis obtained by shifting 311. The two inclined surfaces of the second gable roof shape 322 are referred to as third and fourth inclined surfaces, respectively.
The third gable roof shape 323 has the third axis 313 as the top. The third gable roof shape 323 is formed in the same shape as the first gable roof shape 321 and is convex in the same direction as the first gable roof shape 321. The third axis 313 is located in a plane including the first axis 311 and the second axis 312 and is orthogonal to the first axis 311 (and the second axis 312). The third shaft 313 is separated from the one end 311a of the first shaft 311 on the first shaft 311 by ½ of the width of the first gable roof shape 321 (the width of the first gable roof shape 321 in the second direction). It passes through the point P301. In plan view, the third axis 313 is in the second direction (arrow B direction) from the end of the first gable roof shape 321 in the third direction (arrow C direction) which is the opposite direction to the second direction (arrow B direction). Extending across the end of the second gable roof shape 322. The two inclined surfaces of the third gable roof shape 323 are referred to as fifth and sixth inclined surfaces, respectively.
The fourth gable roof shape 324 has the fourth axis 314 as the top. The fourth gable roof shape 324 is formed in the same shape as the first gable roof shape 321 and is convex in the same direction as the first gable roof shape 321. The fourth axis 314 is formed by shifting the third axis 313 in the first direction (arrow A direction) by the same width as the width of the first gable roof shape 321 (the width of the first gable roof shape 321 in the second direction). The resulting axis. The two inclined surfaces of the fourth gable roof shape 324 are referred to as seventh and eighth inclined surfaces, respectively.
Each of the gable roof shapes 321 to 324 penetrates the other two gable roof shapes whose axial directions are orthogonal to each other (for example, the first gable roof shape 321 is the third gable roof shape 323 and the fourth gable roof shape). 324)
Of the eight inclined surfaces (first to eighth inclined surfaces), the unit 340 has the other seven inclined surfaces when viewed from the convex direction of the first to fourth gable roof shapes 321 to 324. It consists of the inclination part each arrange | positioned along the part which is not covered by any of these.

Therefore, in the case of the present embodiment, the second light transmissive layer 120 naturally includes a plurality of inclined portions inclined with respect to the light emitting layer in opposite directions. The second light transmissive layer 120 includes a plurality of inclined portions that are inclined with respect to the light emitting layer in the same direction.

Furthermore, the second light-transmitting layer 120 naturally intersects the first inclined portion inclined with respect to the light emitting layer around the first axis extending in the first direction in plan view and the first direction in plan view. And a second inclined portion inclined with respect to the light emitting layer around a second axis (specifically orthogonal).

For example, a plurality of units 340 shown in FIG. 15A are arranged side by side without any gap.

In this example, the absolute value of the angle of the first to eighth inclined surfaces with respect to the light emitting layer is, for example, 45 degrees.

The first light-transmitting layer 110 is composed of a first portion 111 and a second portion 112, the barrier film 70 is formed between the first light-transmitting layer 110 and the first electrode 40, and the first The point that the light extraction film 130 is affixed on the upper surface of the light transmissive layer 110 is the same as in the third embodiment.

FIG. 15B shows, for example, a light emitting element that passes through a midpoint P311 at both ends of the third axis 313 and a midpoint P312 at both ends of the fourth axis 314 and is orthogonal to the light emitting layer. It is sectional drawing when cutting. It can be seen that this cross section is the same as the cross sectional shape of the third embodiment (FIG. 7). For this reason, also in the present embodiment, the same effect of improving the light extraction efficiency as in the third embodiment can be obtained.

Further, since the second light transmitting layer 120 is configured by arranging a plurality of units 340 having the above-described configuration in a direction parallel to the light emitting layer, for example, a cross-sectional shape as illustrated in FIG. Become. This cross-sectional shape is the same as that in the third embodiment (FIG. 7). For this reason, the same effect as that of the third embodiment can be obtained by this embodiment.

In this embodiment, the unit 340 may be turned upside down from that shown in FIG.
Further, the vertical direction of each of the plurality of units 340 may be different (the vertical direction may be set individually).

(Example 10)
FIG. 16A is a cross-sectional view of the periphery of the second light transmitting layer 120 of the light emitting device according to this example, and FIG. 16B is a diagram for explaining the effect of the light emitting device according to this example.

In the case of the present example, the refractive index of the second light transmitting layer 120 is higher toward the light emitting layer side.

More specifically, the second light transmitting layer 120 is configured by, for example, laminating a plurality of layers. And the refractive index of these several layers is so high that it becomes a layer by the side of a light emitting layer.

In FIG. 16A, the second light transmitting layer 120 includes a first layer 401, a second layer 402, a third layer 403, and a fourth layer 404 in order from the light extraction side. For example, the refractive index of the first layer 401 is 1.3, the refractive index of the second layer 402 is 1.4, the refractive index of the third layer 403 is 1.5, and the refractive index of the fourth layer 404 is 1.6. It has become. Further, the refractive indexes of the first portion 111 and the second portion 112 are, for example, 1.8, respectively.

For this reason, the amount of change in the refractive index is relatively small at the interface between the second portion 112 and the second light transmissive layer 120, and the refractive index toward the light extraction side in the second light transmissive layer 120. However, the refractive index changes sharply at the interface between the second light transmitting layer 120 and the first portion 111 of the first light transmitting layer 110. In other words, when straddling the second light transmitting layer 120 from the light emitting layer side toward the light extraction side, the refractive index gradually decreases and then increases rapidly.

With this configuration, light (light including a downward component) reaching the second light transmitting layer 120 from the light extraction side is totally reflected at the interface between the first portion 111 and the second light transmitting layer 120. It becomes easy.
On the other hand, light reaching the second light transmissive layer 120 from the light emitting layer side (light including an upward component) is likely to enter the second light transmissive layer 120 from the second portion 112, and consequently the second light transmissive layer 120. In addition, the light passes through the first light transmissive layer 110 and is easily emitted to the outside from the light extraction surface d.
Therefore, the light extraction efficiency of the light emitting element is improved.

FIG. 16B shows the relationship between the incident angle (horizontal axis) of light and the transmittance (vertical axis) with respect to the second light transmitting layer 120. At the interface where the refractive index changes sharply (interface between the first portion 111 and the second light transmitting layer 120), as shown by the curve A401 in FIG. 16B, gradually from the angle before the critical angle is reached. Reflection occurs. On the other hand, when the refractive index gradually changes (when entering the second light transmitting layer 120 from the second portion 112 side), the transmittance ratio changes in the direction of the arrow D in FIG. The amount of reflection decreases. For this reason, by adopting the structure as shown in FIG. 16A, the light traveling from the light extraction side toward the second light transmissive layer 120 has more reflection near the critical angle, and the second light transmissive layer from the light emitting layer side. With respect to light directed to 120, it becomes possible to increase the transmission near the critical angle.

According to the present example, the refractive index of the second light transmitting layer 120 is higher toward the light emitting layer side. Thereby, the light extraction efficiency of the light emitting element is improved.

In the present embodiment, the refractive index of the second light transmissive layer 120 may increase continuously toward the light emitting layer instead of stepwise.

(Example 11)
FIG. 17 is a cross-sectional view of the light emitting device according to this example. The light emitting device according to this example is different from the light emitting device according to Example 4 described above (FIG. 10) in the points described below, and is otherwise configured in the same manner as the light emitting device according to Example 4. Yes.

In the case of the present embodiment, the light emitting element may have the light extraction film 130 but may not have the light extraction film 130 as shown in FIG. A translucent protective member (for example, protective glass) 160 is disposed above the first translucent layer 110. The protection member 160 is supported on the base member 80 via the support member 84, for example. On the base member 80, the light emitting element having the structure described in the fourth embodiment is fixed. The space surrounded by the base member 80, the protection member 160, and the support member 84 is sealed. Note that a gas (for example, air or inert gas) is filled between the protective member 160 and the first light transmissive layer 110. In the case of the present embodiment, the upper surface of the protection member 160 constitutes the light extraction surface d.

The base member 80 can be a sealing body (sealing layer), 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.

Also in this embodiment, the same effect as that of Embodiment 4 can be obtained. Moreover, since the 1st translucent layer 110 is protected by the protection member 160, durability of a light emitting element can be improved.

Example 12
FIG. 18 is a cross-sectional view of the light emitting device according to this example. In the above description, an example in which the first light transmissive layer 110 and the first electrode 40 are provided separately has been described. However, as shown in FIG. 18, the second portion 112 of the first light transmissive layer 110 is formed of a light transmissive electrode. You may have a function. That is, in this case, the second portion 112 is configured by a light-transmitting conductor such as a metal oxide conductor such as ITO. According to the present embodiment, since the second portion 112 of the first light transmissive layer 110 also functions as a light transmissive electrode, it is possible to reduce the number of parts of the light emitting element.

(Example 13)
FIG. 19 is a cross-sectional view of the light emitting device according to this example. As shown in FIG. 19, a light-transmitting protective film 170 may be formed on the upper surface of the first light-transmitting layer 110. The protective film 170 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 170 is formed by using, for example, a vapor phase growth method such as a CVD method or a sputtering method. In this embodiment, the upper surface of the protective film 170 constitutes the light extraction surface d.

Also in this example, the same effect as in the above embodiment can be obtained. In addition, since the first light transmissive layer 110 is protected by the protective film 170, the durability of the light emitting element can be improved.

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.

Claims

An organic functional layer including a light emitting layer;
A first light transmissive layer disposed on the light extraction side with respect to the organic functional layer;
A second light-transmitting layer having a refractive index lower than that of the first light-transmitting layer and embedded in the first light-transmitting layer;
With
At least a part of the second light transmissive layer is an inclined portion inclined with respect to the light emitting layer,
The surface on the organic functional layer side and the surface on the light extraction side in the inclined portion are inclined with respect to the light emitting layer, respectively.
The light emitting element in which the surface by the side of the said organic functional layer in the said inclination part and the surface by the side of the said light extraction are in contact with the said 1st light transmission layer, respectively.
The light emitting device according to claim 1, wherein the second light transmitting layer includes a plurality of the inclined portions inclined with respect to the light emitting layer at different inclination angles.
The light emitting device according to claim 1 or 2, wherein the second light transmitting layer includes a plurality of the inclined portions inclined with respect to the light emitting layer in opposite directions.
4. The light emitting device according to claim 1, wherein the second light transmitting layer includes a plurality of the inclined portions inclined with respect to the light emitting layer in the same direction.
The second light-transmitting layer intersects the first inclined portion inclined with respect to the light emitting layer around a first axis extending in the first direction in plan view, and intersects the first direction in plan view. The light emitting device according to any one of claims 1 to 4, further comprising a second inclined portion inclined about the two light axes with respect to the light emitting layer.
The second translucent layer is
Each side surface of the truncated pyramid whose cross-sectional area is reduced toward either the light extraction side or the light emitting layer side;
A pyramid having the same number of side faces as the pyramid frustum and having a lower base coinciding with the upper base of the frustum frustum, the cross-sectional area of which decreases toward either the light extraction side or the light emitting layer side Each side of
A unit composed of the inclined portions respectively disposed along
The light emitting device according to claim 1, wherein a plurality of light emitting elements are arranged in a direction parallel to the light emitting layer.
The light emitting device according to claim 6, wherein the height of the truncated pyramid and the height of the truncated pyramid are equal to each other.
The second translucent layer is
Each side surface of the truncated pyramid whose cross-sectional area is reduced toward either the light extraction side or the light emitting layer side;
A first base having the same number of side surfaces as the truncated pyramid and having a lower base coinciding with the upper base of the truncated pyramid, the cross-sectional area being reduced toward either the light extraction side or the light emitting layer side; Each side of the truncated pyramid,
A unit composed of the inclined portions respectively disposed along
The light emitting device according to claim 1, wherein a plurality of light emitting elements are arranged in a direction parallel to the light emitting layer.
The light emitting device according to claim 8, wherein a height of the truncated pyramid and a height of the second truncated pyramid are equal to each other.
10. The light emitting device according to claim 6, wherein the truncated pyramid is a rectangular truncated pyramid having a rectangular shape in plan view.
The light emitting device according to any one of claims 6 to 10, wherein the plurality of units are arranged without a gap so that one side of the lower base of the truncated pyramid defining the shape of each other coincides with each other.
The light emitting device according to any one of claims 1 to 11, wherein a refractive index of the second light transmitting layer is increased toward the light emitting layer side.
The light-emitting element according to any one of claims 1 to 12, wherein the first light-transmitting layer includes a light-transmitting substrate disposed closer to the light extraction side than the second light-transmitting layer.
The light emitting element according to claim 13, wherein a refractive index of a portion of the first light transmissive layer between the second light transmissive layer and the light transmissive substrate is equal to a refractive index of the light transmissive substrate.
The portion on the light extraction side of the first light transmissive layer with respect to the second light transmissive layer is made of a light transmissive substrate.
The light-emitting element according to claim 13, wherein the light-transmitting substrate is in contact with the light extraction side surface of the second light-transmitting layer.