WO2014080477A1 - Light emitting device - Google Patents

Abstract

This light emitting device (100) comprises: an organic functional layer (140) including a light emitting layer; and an optical-path changing layer (120) that changes the optical path of light from the light emitting layer. The optical-path changing layer (120) includes a plurality of refractive-index changing parts (121). If the peak wavelength of the light emission spectrum of the light from the light emitting layer is defined as λ, the size of each refractive-index changing part (121) is smaller than λ/2. The plurality of refractive-index changing parts (121) are arranged so as to be evenly spaced by a first interval in a first direction that is parallel to the organic functional layer (140), and are arranged so as to be evenly spaced by a second interval in a second direction that is parallel to the organic functional layer (140) and that intersects the first direction.

Description

Light emitting device

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

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

As a technique for improving the light extraction efficiency, there is a technique described in Patent Document 1. The light emitting device described in Patent Literature 1 includes a substrate, an organic functional layer, a cathode, and an anode. An anode or a cathode is disposed between the substrate and the organic functional layer, and a cathode or an anode is disposed on the opposite side of the substrate from the organic functional layer. Patent Document 1 describes that light extraction efficiency is improved by forming irregularities between the organic functional layer and the anode or between the organic functional layer and the cathode.

JP 2002-260868 A

The inventor considered that the technique described in Patent Document 1 has the following problems.
In the technique of Patent Document 1, the anode or the cathode has an uneven shape. For this reason, a leakage current may occur between the anode and the cathode.

An example of a problem to be solved by the present invention is to achieve both light extraction efficiency and reliability of a light emitting device.

The invention according to claim 1 includes an organic functional layer including at least a light emitting layer;
An optical path changing layer that is disposed on one surface side of the organic functional layer and changes an optical path of light from the light emitting layer;
With
The optical path changing layer is
The base region,
The refractive index is different from that of the base region, and the refractive index changing portion disposed in the base region;
Including
When the peak wavelength of the emission spectrum of the light from the light emitting layer is λ, the dimension of the refractive index changing portion is smaller than λ / 2,
The plurality of refractive index changing portions are arranged at equal intervals at a first interval in a first direction parallel to the organic functional layer, and are parallel to the organic functional layer and intersect with the first direction. It is the light-emitting device arrange | positioned at equal intervals by the 2nd space | interval in a 2nd direction.

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.

1A is a cross-sectional view of the light emitting device according to the embodiment, FIG. 1B is an enlarged view of a portion A in FIG. 1A, and FIG. 1C is an enlarged view of a B portion in FIG. FIG. It is a top view of the optical path changing layer of the light-emitting device concerning an embodiment. It is a figure which shows an example of the change characteristic of the refractive index in the optical path change layer of the light-emitting device which concerns on embodiment. It is a figure which shows another example of the change characteristic of the refractive index in the optical path change layer of the light-emitting device which concerns on embodiment. It is a figure which shows another example of the change characteristic of the refractive index in the optical path change layer of the light-emitting device which concerns on embodiment. 6A is a plan view showing an example of a more specific structure of the light emitting device according to the embodiment, and FIG. 6B is a cross-sectional view taken along the line BB in FIG. 6A. is there. FIG. 7A is a plan view showing the light emitting layer and the partition wall, FIG. 7B is an example of an enlarged view of part A in FIG. 7A, and FIG. 7C is A in FIG. It is another example of the enlarged view of a part. FIG. 8A and FIG. 8B are cross-sectional views illustrating a part of the process of manufacturing the light emitting device according to the embodiment. It is sectional drawing which shows the 1st example of an organic functional layer. It is sectional drawing which shows the 2nd example 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. 6 is a cross-sectional view of a light emitting device according to Example 3. FIG. 12 is a cross-sectional view illustrating a part of the process of manufacturing the light-emitting device according to Example 3. FIG. 6 is a cross-sectional view of a light emitting device according to Example 4. FIG. 6 is a cross-sectional view of a light emitting device according to Example 5. FIG. 6 is a cross-sectional view of a light emitting device according to Example 6. FIG. FIG. 18A and FIG. 18B are cross-sectional views illustrating a part of the process of manufacturing the light emitting device according to the sixth embodiment. 7 is a cross-sectional view of a light emitting device according to Example 7. FIG. 10 is a cross-sectional view of a light emitting device according to Example 8. FIG. 10 is a cross-sectional view of a light emitting device according to Example 9. FIG. It is sectional drawing of the light-emitting device based on Example 10. FIG. 12 is a sectional view of a light emitting device according to Example 11. FIG. It is sectional drawing of the light-emitting device based on Example 12. It is sectional drawing of the light-emitting device based on Example 13. It is sectional drawing of the light-emitting device based on Example 14. It is sectional drawing of the light-emitting device based on Example 15.

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)
1A is a cross-sectional view of the light emitting device 100 according to the embodiment, FIG. 1B is an enlarged view of a portion A in FIG. 1A, and FIG. 1C is a view of a B portion in FIG. It is an enlarged view. FIG. 2 is a plan view of the optical path changing layer 120 of the light emitting device 100 according to the embodiment. The light emitting device 100 includes an organic EL (Electro Luminescence) element. The light emitting device 100 can be used as a light source of, for example, a display, a lighting device, or an optical communication device.

The light emitting device 100 according to this embodiment includes an organic functional layer 140 including at least a light emitting layer, an optical path changing layer 120 that is disposed on one surface side of the organic functional layer 140, and changes an optical path of light from the light emitting layer, Is provided. The optical path changing layer 120 includes a base region 122 and a refractive index changing portion 121 having a refractive index different from that of the base region 122 and disposed in the base region 122. When the peak wavelength of the emission spectrum of light from the light emitting layer is λ, the dimension D of the refractive index changing portion 121 is smaller than λ / 2. A plurality of refractive index changing portions 121 are arranged at equal intervals at a first interval in a first direction parallel to the organic functional layer 140, and are parallel to the organic functional layer 140 and intersect with the first direction. They are arranged at equal intervals at second intervals in two directions. Note that the first direction and the second direction are, for example, directions orthogonal to each other. Further, the first interval and the second interval are equal to each other, for example. Examples of such an arrangement of the plurality of refractive index changing sections 121 include a regular lattice arrangement, a staggered lattice arrangement, and an orthorhombic lattice arrangement. Note that the first interval and the second interval may be different from each other.

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 device 100 is the relationship shown in each drawing. However, the positional relationship in this description is irrelevant to the positional relationship when the light emitting device 100 is used.

The light emitting device 100 further includes a translucent substrate 110 disposed to face the organic functional layer 140, and a translucent first disposed between the translucent substrate 110 and the organic functional layer 140. The electrode 130 and the 2nd electrode 150 arrange | positioned on the opposite side to the 1st electrode 130 on the basis of the organic functional layer 140 are provided. In the present embodiment, the optical path changing layer 120 is disposed between the translucent substrate 110 and the first electrode 130 and emits light from the light emitting device 100 to the outside (that is, the light extraction surface 110a side). Is the translucent substrate 110 side with respect to the optical path changing layer 120.

The translucent substrate 110 is a plate-like member made of a translucent material such as glass or resin. In the case of this embodiment, the upper surface of the translucent substrate 110, that is, the surface of the translucent substrate 110 opposite to the organic functional layer 140 is a flat light extraction surface 110a. The light extraction surface 110a is in contact with air (refractive index 1) filling the light emission space. In addition, the light extraction film may be affixed on the upper surface of the translucent board | substrate 110, and the upper surface of this light extraction film may comprise the light extraction surface.

The first electrode 130 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 130 may be a metal thin film that is thin enough to transmit light.

The second electrode 150 is a reflective electrode made of a metal film such as Al. The second electrode 150 reflects light traveling from the organic functional layer 140 toward the second electrode 150 toward the translucent substrate 110.

When a voltage is applied between the first electrode 130 and the second electrode 150, the light emitting layer of the organic functional layer 140 emits light. The first electrode 130, the base region 122 of the optical path changing layer 120, the refractive index changing portion 121 of the optical path changing layer 120, the translucent substrate 110, and the organic functional layer 140 are all the light emitting layer of the organic functional layer 140. Transmits at least part of the emitted light. Part of the light emitted from the light emitting layer is emitted (extracted) from the light extraction surface 110a of the translucent substrate 110 to the outside of the light emitting device 100 (that is, the light emission space).

For example, in the optical path changing layer 120, all regions other than the refractive index changing portion 121 are the base region 122. However, the optical path changing layer 120 may include a region other than the refractive index changing portion 121 and the base region 122. The optical path changing layer 120 is made of, for example, a dielectric material.

The optical path changing layer 120 has a plurality of (many) refractive index changing portions 121. When the peak wavelength (for example, the maximum peak wavelength) of the emission spectrum of light from the light emitting layer is λ, the dimension D (FIG. 1C) of each refractive index changing portion 121 is smaller than λ / 2. Here, the dimension D of the refractive index changing portion 121 means the maximum dimension of the outer shape of each refractive index changing portion 121 in plan view. As an example, the refractive index changing portion 121 may be spherical, and in this case, the dimension D is the outer diameter of the refractive index changing portion 121.

The plurality of refractive index changing portions 121 are arranged at equal intervals at a first interval in the first direction, and are arranged at equal intervals at a second interval in the second direction. Here, the interval between the refractive index changing portions 121 means the center-to-center distance d between adjacent refractive index changing portions 121 (FIG. 1C). For example, the center distance d between adjacent refractive index changing portions 121 is constant.

The plurality of refractive index changing portions 121 arranged in this way constitutes a photonic crystal. Among the light emitted from the light emitting layer of the organic functional layer 140, a part of the light incident on the optical path changing layer 120 is almost equal to the organic functional layer 140 by the photonic crystal composed of the plurality of refractive index changing portions 121. The direction (optical path) is changed in the orthogonal direction. Thereby, this light is radiated to the outside of the light emitting device 100 through the optical path changing layer 120 and the translucent substrate 110.

The center-to-center distance d between adjacent refractive index changing portions 121 is preferably λ / 2 or more and λ or less.

The dimension of the refractive index changing portion 121 is preferably λ / 10 or more.

For example, the refractive index of the refractive index changing portion 121 is smaller than the refractive index of the base region 122. For example, the refractive index difference between the refractive index changing portion 121 and the base region 122 increases as the distance from the boundary between the refractive index changing portion 121 and the base region 122 increases inward. That is, the refractive index of the refractive index changing portion 121 decreases as the distance from the boundary between the refractive index changing portion 121 and the base region 122 increases.

FIG. 3 is a diagram illustrating an example of a change characteristic of the refractive index in the optical path changing layer 120. That is, FIG. 3 shows an example of a change characteristic of the refractive index from one end C1 to the other end C2 of the line segment C shown in FIG. For example, in the base region 122, the refractive index is constant regardless of the position (region R1 and region R4 in FIG. 3). The refractive index of the boundary between the base region 122 and the refractive index changing portion 121 (the boundary between the region R1 and the region R2 and the boundary between the region R4 and the region R3 in FIG. 3) is the same as the refractive index of the base region 122. In the refractive index changing portion 121, the refractive index gradually decreases as the distance from the boundary between the refractive index changing portion 121 and the base region 122 increases, that is, toward the center of the refractive index changing portion 121 (see FIG. 3). Region R2, region R3). Thus, for example, the refractive index of the refractive index changing portion 121 is the same as the refractive index of the base region 122 at the boundary with the base region 122, and gradually decreases as the distance from the boundary increases.

The refractive index changing portion 121 is formed by heating a part of the optical path changing layer 120 (base region 122), for example. Therefore, as the material of the optical path changing layer 120, for example, a material whose refractive index is lowered by heating can be used. The material of the optical path changing layer 120 can be a material having a refractive index equal to or higher than the refractive index of the organic functional layer 140 and having a low refractive index when heated. Examples of such materials include phthalocyanine-based or azo-based organic materials used for DVDs or CDs. Further, as the material of the optical path changing layer 120, the material used for the organic functional layer 140 may be used, and the refractive index changing portion 121 may be formed by heating a part of the optical path changing layer 120 in a short time. The optical path changing layer 120 is made of a dielectric, for example. By heating a part of the optical path changing layer 120, the molecules are decomposed, and the refractive index of the heated part is lowered.

The refractive index changing portion 121 is a portion where the base region 122 is crystallized, and the refractive index of the refractive index changing portion 121 may be larger than the refractive index of the base region 122. For example, also in this case, the refractive index difference between the refractive index changing portion 121 and the base region 122 increases as the distance from the boundary between the refractive index changing portion 121 and the base region 122 increases inward. . That is, the refractive index of the refractive index changing portion 121 increases as the distance from the boundary between the refractive index changing portion 121 and the base region 122 increases.
FIG. 4 is a diagram illustrating another example of the change characteristic of the refractive index in the optical path changing layer 120. That is, FIG. 4 shows another example of the change characteristic of the refractive index from one end C1 to the other end C2 of the line segment C shown in FIG. For example, in the base region 122, the refractive index is constant regardless of the position (region R1 and region R4 in FIG. 4). The refractive index of the boundary between the base region 122 and the refractive index changing portion 121 (the boundary between the region R1 and the region R2 and the boundary between the region R4 and the region R3 in FIG. 4) is the same as the refractive index of the base region 122. In the refractive index changing portion 121, the refractive index gradually increases as the distance from the boundary between the refractive index changing portion 121 and the base region 122 increases, that is, toward the center of the refractive index changing portion 121 (see FIG. 4). Region R2, region R3). Thus, for example, the refractive index of the refractive index changing portion 121 is the same as the refractive index of the base region 122 at the boundary with the base region 122 and gradually increases as the distance from the boundary increases.

In this case, as the material of the optical path changing layer 120 (base region 122), a material whose refractive index is increased by heating can be used. When a part of the optical path changing layer 120 (base region 122) of such a material is heated and then cooled, the material constituting the optical path changing layer 120 (base region 122) is crystallized. As a result, the refractive index of the portion becomes higher than the refractive index of the surrounding portion (that is, the base region 122), and gradually increases as the refractive index of the portion moves away from the base region 122, for example. As a material of the optical path changing layer 120, for example, NPB (N, N-di (naphthalene-1-yl) -N, N-diphenyl-benzidine) used as a material of the organic functional layer 140 can be used.

The refractive index changing portion 121 may be a bubble. For example, bubbles can be partially formed in the optical path changing layer 120 by concentrically heating a part of the optical path changing layer 120 (base region 122) in a very short time to evaporate the material of the part.
FIG. 5 is a diagram showing still another example of the refractive index change characteristic in the optical path changing layer 120. That is, FIG. 5 shows still another example of the refractive index change characteristic from one end C1 to the other end C2 of the line segment C shown in FIG. For example, in the base region 122, the refractive index is constant regardless of the position (region R1 and region R4 in FIG. 5). The refractive index changes sharply at the boundary between the base region 122 and the refractive index changing portion 121 (the boundary between the region R1 and the region R2 and the boundary between the region R4 and the region R3 in FIG. 4). Since the refractive index changing portion 121 is a bubble, the refractive index of the refractive index changing portion 121 (region R2 and region R3 in FIG. 4) is smaller than the refractive index of the base region 122 and is constant.

For example, one surface (the lower surface in FIG. 1) of the translucent substrate 110 and one surface (the upper surface in FIG. 1) of the optical path changing layer 120 are in contact with each other. Further, the other surface (lower surface in FIG. 1) of the optical path changing layer 120 and one surface (upper surface in FIG. 1) of the first electrode 130 are in contact with each other. Further, the other surface (lower surface in FIG. 1) of the first electrode 130 and one surface (upper surface in FIG. 1) of the organic functional layer 140 are in contact with each other. Further, the other surface (lower surface in FIG. 1) of the organic functional layer 140 and one surface (upper surface in FIG. 1) of the second electrode 150 are in contact with each other. However, another layer may exist between the translucent substrate 110 and the optical path changing layer 120. Similarly, another layer may exist between the optical path changing layer 120 and the first electrode 130. Similarly, another layer may exist between the first electrode 130 and the organic functional layer 140. Similarly, another layer may exist between the organic functional layer 140 and the second electrode 150.

6A is a plan view showing an example of a more specific structure of the light emitting device 100 according to the embodiment, and FIG. 6B is a cross-sectional view taken along line BB in FIG. 6A. It is. In FIGS. 6B and 6A, the top and bottom are inverted from FIG. 1A.

The first electrode 130 constitutes an anode. The plurality of first electrodes 130 each extend in the Y direction in a strip shape. Adjacent first electrodes 130 are spaced apart from each other at a constant interval in the X direction orthogonal to the Y direction. Each of the first electrodes 130 is made of a metal oxide conductor such as ITO or IZO, for example. The refractive index of the first electrode 130 is approximately the same as that of the optical path changing layer 120 (for example, approximately 1.8). A bus line (bus electrode) 170 for supplying a power supply voltage to the first electrode 130 is formed on each surface of the first electrode 130. An insulating film is formed on the optical path changing layer 120 and the first electrode 130. In this insulating film, a plurality of stripe-shaped openings each extending in the Y direction are formed. Thereby, a plurality of partition walls 180 made of an insulating film are formed. Each of the openings formed in the insulating film reaches the first electrode 130, and the surface of each first electrode 130 is exposed at the bottom of the opening. An organic functional layer 140 is formed on the first electrode 130 in each opening of the insulating film. The organic functional layer 140 is configured by stacking a hole injection layer 141, a hole transport layer 142, a light emitting layer 143 ( light emitting layers 143R, 143G, 143B), and an electron transport layer 144 in this order. Materials for the hole injection layer 141 and the hole transport layer 142 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 143R, 143G, and 143B are made of a fluorescent organometallic compound that emits red light, green light, and blue light, respectively. The light emitting layers 143R, 143G, and 143B are arranged side by side in a state of being separated from each other by the partition wall portion 180. That is, the organic functional layer 140 is partitioned into a plurality of regions by the partition wall portion 180. An electron transport layer 144 is formed so as to cover the surfaces of the light emitting layers 143R, 143G, and 143B and the partition wall portion 180. A second electrode 150 is formed so as to cover the surface of the electron transport layer 144. The second electrode 150 constitutes a cathode. The second electrode 150 is formed in a band shape. The second electrode 150 is made of a metal such as Al or an alloy having a low work function and high reflectivity. The refractive index of the organic functional layer 140 is approximately the same as that of the first electrode 130 and the optical path changing layer 120 (for example, a refractive index of approximately 1.8).

In this manner, the light emitting layers 143R, 143G, and 143B that emit red, green, and blue light are repeatedly arranged in stripes, and the red, green, and green light is emitted from the surface of the translucent substrate 110 that serves as a light extraction surface. , Blue light is mixed at an arbitrary ratio to emit light that is recognized as a single emission color (for example, white).

7A is a plan view showing the light emitting layers 143R, 143G, and 143B and the partition wall portion 180, FIG. 7B is an example of an enlarged view of a portion A in FIG. 7A, and FIG. These are other examples of the enlarged view of the A section of Fig.7 (a). 7B and 7C, the refractive index changing portion 121 of the portion of the optical path changing layer 120 disposed above the light emitting layer 143R is illustrated, and the bus line 170 on the partition wall portion 180 is illustrated. It is shown.

As shown in FIGS. 7B and 7C, the plurality of refractive index changing portions 121 are two-dimensionally dispersed at a uniform interval in the region above each light emitting layer 143R, 143G, 143B. Are arranged. In addition, as shown in FIG.7 (b), the refractive index change part 121 does not need to be arrange | positioned in the area | region above the partition part 180, and each light emitting layer 143R is shown in FIG.7 (c). , 143G, 143B, the refractive index changing portion 121 may be disposed not only in the region above the partition wall portion 180, but also in the region above the partition wall portion 180.

Here, each of the light emitting layers 143R, 143G, and 143B emits light having different emission spectra. The peak wavelengths λ of the emission spectra of light from the light emitting layers 143R, 143G, and 143B are different from each other.
When the peak wavelength of the emission spectrum of red light emitted from the light emitting layer 143R is λR, the plurality of refractive index changing portions 121 arranged in the region on the light emitting layer 143R has a dimension of λR / 10 or more and λR / 2. Smaller than. Further, for the plurality of refractive index changing portions 121 arranged in the region on the light emitting layer 143R, the center-to-center distance between adjacent refractive index changing portions 121 is not less than λR / 2 and not more than λR.
Similarly, assuming that the peak wavelength of the emission spectrum of green light emitted from the light emitting layer 143G is λG, the plurality of refractive index changing portions 121 arranged in the region on the light emitting layer 143G have a dimension of λG / 10 or more and It is smaller than λG / 2. Further, for the plurality of refractive index changing portions 121 arranged in the region on the light emitting layer 143G, the center-to-center distance between adjacent refractive index changing portions 121 is not less than λG / 2 and not more than λG.
Similarly, assuming that the peak wavelength of the emission spectrum of blue light emitted from the light emitting layer 143B is λB, the plurality of refractive index changing portions 121 arranged in the region on the light emitting layer 143B have a size of λB / 10 or more and It is smaller than λB / 2. Further, regarding the plurality of refractive index changing portions 121 arranged in the region on the light emitting layer 143B, the center-to-center distance between adjacent refractive index changing portions 121 is not less than λB / 2 and not more than λB.

Next, an example of a process for manufacturing the light emitting device 100 according to the embodiment will be described. FIGS. 8A and 8B are cross-sectional views showing a part of this process.

First, an organic material such as phthalocyanine-based, azo-based, or NPB is formed on the lower surface of the translucent substrate 110 to form a portion that becomes the base region 122 in the optical path changing layer 120 (FIG. 8A). Note that the refractive index changing portion 121 is formed at an appropriate timing after the base region 122 is formed. The timing and method for forming the refractive index changing portion 121 will be described later.

Next, a light-transmitting conductive film made of a metal oxide conductor such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide) is formed on the lower surface of the optical path changing layer 120 (base region 122) by sputtering or the like. A first electrode 130 is formed by patterning the film by etching.

Next, the organic functional layer 140 is formed by depositing an organic material on the lower surface of the first electrode 130.

Next, a second electrode 150 is formed by depositing a metal material such as Al in a desired pattern on the lower surface of the organic functional layer 140 by vapor deposition using a mask or the like.

Note that the bus line 170 and the partition wall portion 180 are formed at appropriate timings as necessary. Further, a sealing layer may be formed on the lower surface of the second electrode 150 as necessary.

Next, how to form the refractive index changing portion 121 will be described.

The refractive index changing portion 121 is formed by heating a part of the optical path changing layer 120 (base region 122) by irradiating light. In addition, it is preferable that the wavelength of the light ray to irradiate is shorter than the light emission wavelength of a light emitting layer. Specifically, for example, by irradiating a part of the optical path changing layer 120 with a laser beam, a part of the optical path changing layer 120 can be heated to form the refractive index changing portion 121 (FIG. 8B). )).

When a material whose refractive index is lowered by heating is used as the material of the optical path changing layer 120, the molecular structure of the material constituting the optical path changing layer 120 is changed by heating a part of the optical path changing layer 120 (base region 122). Or the density distribution of the material constituting the optical path changing layer 120 changes (the density decreases). That is, the material constituting the optical path changing layer 120 is thermally changed. Thereby, the refractive index of the said part falls.

In addition, when a material whose refractive index is increased by heating is used as the material of the optical path changing layer 120, the optical path changing layer 120 is configured by heating and cooling a part of the optical path changing layer 120 (base region 122). Crystallization of the material occurs. Thereby, the refractive index of the said part becomes higher than the refractive index of the surrounding part (namely, base region 122).

Here, the intensity distribution of the irradiated light (laser light or the like) is a Gaussian distribution, and the intensity at the center of the irradiation spot of the light is increased. For this reason, the closer to the center of the irradiation spot, the greater the influence on the molecular structure, density distribution, etc. of the material constituting the optical path changing layer 120. Therefore, the refractive index of the refractive index changing unit 121 is gradually reduced or increased toward the center of the irradiation spot, for example.

Further, by heating a part of the optical path changing layer 120 (base region 122) and evaporating the material of the part, bubbles are partially formed in the optical path changing layer 120, and the bubbles are used as the refractive index changing portion 121. Also good.

The timing for forming the refractive index changing portion 121 can be any timing after the optical path changing layer 120 (base region 122) is formed.

When the refractive index changing portion 121 is formed after the formation of the optical path changing layer 120 (base region 122) and before the formation of the first electrode 130, light is emitted from any surface side of the optical path changing layer 120 (base region 122). It may be irradiated.
In addition, in the case where the refractive index changing portion 121 is formed after the formation of the first electrode 130 and before the formation of the organic functional layer 140, a translucent substrate is used in order to suppress damage to the first electrode 130 due to light irradiation. Light is irradiated from the 110 side.
In any of these cases, the organic functional layer 140 has not yet been formed. For this reason, since it is not necessary to consider the damage to the organic functional layer 140, either a CW laser (continuous wave oscillation operation laser) or a pulse laser may be used.

Further, after the organic functional layer 140 and the second electrode 150 are formed, the refractive index changing portion 121 may be formed after the sealing is completed and the light emitting device 100 having a panel structure is constructed. In this case, light is irradiated from the translucent substrate 110 side. In this case, in order to use a CW laser or a pulse laser, it is preferable to consider that heat is not applied to the organic functional layer 140 as much as possible. Alternatively, a femtosecond laser or a nanosecond laser may be used.

Note that the light irradiation for forming the refractive index changing portion 121 is not limited to the laser light irradiation. For example, the refractive index changing portion 121 can also be formed by allowing light having a single wavelength other than a laser to pass through a mask and condensing with a lens and forming an image on a part of the optical path changing layer 120. Can do.

(First example of organic functional layer)
FIG. 9 is a diagram illustrating a first example of the layer structure of the organic functional layer 140. The organic functional layer 140 according to the first example has a structure in which a hole injection layer 141, a hole transport layer 142, a light emitting layer 143, an electron transport layer 144, and an electron injection layer 145 are stacked in this order. That is, the organic functional layer 140 is an organic electroluminescence light emitting layer. Note that instead of the hole injection layer 141 and the hole transport layer 142, one layer having the functions of these two layers may be provided. Similarly, instead of the electron transport layer 144 and the electron injection layer 145, one layer having the functions of these two layers may be provided (see FIG. 6B).

In the first example of the organic functional layer, the light emitting layer 143 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, in a plan view, a region having a light emitting layer 143 that emits red light, a region having a light emitting layer 143 that emits green light, and a region having a light emitting layer 143 that emits blue light are repeatedly provided. (See FIG. 6B). In this case, when each region emits light simultaneously, the light emitting device 100 emits light in a single light emission color such as white.

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

(Second example of organic functional layer)
FIG. 10 is a diagram illustrating a second example of the layer structure of the organic functional layer 140. FIG. 6 illustrates an example in which the regions separated from each other by the partition wall portion 180 in the organic functional layer 140 emit red light, green light, and blue light, respectively. On the other hand, in the second example, the light emitting layer 143 of the organic functional layer 140 has a configuration in which the light emitting layers 143a, 143b, and 143c are stacked in this order. The light emitting layers 143a, 143b, and 143c emit light of different colors (for example, red, green, and blue). The light emitting layers 143a, 143b, and 143c emit light at the same time, so that the light emitting device 100 emits light in a single light emission color such as white. Here, when it is desired to improve the light extraction efficiency of any one of the light emission from the light emitting layers 143a, 143b, and 143c, the peak wavelength of the emission spectrum of the light (the peak wavelengths λR, λG, and λB described above). The area ratio (area ratio in plan view) of the region where the dimension of the refractive index changing portion 121 and the center-to-center distance between adjacent refractive index changing portions 121 are set in correspondence with any one) The dimension of the refractive index changing portion 121 and the center-to-center distance between adjacent refractive index changing portions 121 are preferably larger than the area ratio of the portion corresponding to the peak wavelength of the other color. For example, when it is desired to improve the light extraction efficiency of light emitted from the light emitting layer 143a that emits red light, the dimensions of the plurality of refractive index changing portions 121 are set to be λR / 10 or more and smaller than λR / 2, and adjacent refractions. The area ratios of the portions in which the distance between the centers of the refractive index changing portions 121 is λR / 2 or more and λR or less correspond to the peak wavelengths of other colors, and the refractive index changing portions 121 adjacent to the dimensions of the refractive index changing portions 121 are adjacent to each other. It is possible to make it larger than the area ratio of the portion where the center-to-center distance is set.

As described above, according to the present embodiment, when the peak wavelength of the emission spectrum of light from the light emitting layer is λ, the dimension of the refractive index changing portion 121 is smaller than λ / 2. The plurality of refractive index changing portions 121 are arranged at equal intervals at a first interval in the first direction, and are arranged at equal intervals at a second interval in the second direction. The plurality of refractive index changing portions 121 constitutes a photonic crystal. Therefore, the direction of light reflected at the interface between the first electrode 130 and the translucent substrate 110 or the interface between the translucent substrate 110 and the light emission space (that is, light having a critical angle or more at each interface). Can be changed in a direction substantially orthogonal to the organic functional layer 140 by the plurality of refractive index changing portions 121. Thereby, since this light can be extracted from the light extraction surface 110a, the light extraction efficiency can be improved.
Unlike the technique of Patent Document 1, it is not necessary to form unevenness between the organic functional layer 140 and the first electrode 130 and between the organic functional layer 140 and the second electrode 150. For this reason, compared with the technique of patent document 1, the reliability of the light-emitting device 100 can be improved.
That is, it is possible to achieve both the light extraction efficiency and reliability of the light emitting device 100.

Further, since the center-to-center distance d between the adjacent refractive index changing portions 121 is not less than λ / 2 and not more than λ, the plurality of refractive index changing portions 121 can function more reliably as a photonic crystal.

For example, the refractive index of the refractive index changing portion 121 is smaller than the refractive index of the base region 122. Thereby, for example, when a material whose refractive index is lowered by heating is used as the optical path changing layer 120, the refractive index changing portion 121 can be formed by heating a part of the optical path changing layer 120.

For example, the refractive index changing portion 121 is a portion where the base region 122 is crystallized, and the refractive index of the refractive index changing portion 121 is larger than the refractive index of the base region 122. Accordingly, for example, when a material that is crystallized by heating to increase the refractive index is used as the optical path changing layer 120, the refractive index changing portion 121 can be formed by heating a part of the optical path changing layer 120. it can.

For example, the refractive index changing portion 121 is a bubble. Thereby, for example, when a material that generates bubbles by heating is used as the optical path changing layer 120, the refractive index changing portion 121 can be formed by heating a part of the optical path changing layer 120.

The light emitting device 100 includes a light transmissive substrate 110 disposed to face the organic functional layer 140, and a light transmissive first electrode 130 disposed between the light transmissive substrate 110 and the organic functional layer 140. And a second electrode 150 disposed on the side opposite to the first electrode 130 with respect to the organic functional layer 140. The optical path changing layer 120 is disposed between the translucent substrate 110 and the first electrode 130, and the light extraction side that emits light from the light emitting device 100 to the outside (that is, the light extraction surface 110 a side) The light transmitting substrate 110 side with respect to the layer 120. Therefore, the direction of the light from the light emitting layer toward the translucent substrate 110 side can be changed to the direction that can be extracted from the light extraction surface 110a by the photonic crystal including the plurality of refractive index changing portions 121.

(Example 1)
FIG. 11 is a cross-sectional view of the light emitting device 100 according to the first embodiment. In the above-described embodiment, a bottom emission type light emitting device that emits light from the translucent substrate 110 has been described. In Example 1, a top emission type light emitting device is described.

The light-emitting device 100 according to Example 1 is different from the light-emitting device 100 according to the above-described embodiment in the points described below, and is configured in the same manner as the light-emitting device 100 according to the embodiment in other points.

On the side opposite to the organic functional layer 140 side of the translucent substrate 110, that is, on the upper surface side of the translucent substrate 110, a light reflecting film 160 is formed. The light reflecting film 160 is made of a metal film such as Al. Note that the upper surface of the light-transmitting substrate 110 and the lower surface of the light reflecting film 160 may be in contact with each other, or even if another layer exists between the light transmitting substrate 110 and the light reflecting film 160. good. In the case of Example 1, the second electrode 150 is translucent. The second electrode 150 can be, for example, a transparent electrode made of a metal oxide conductor such as ITO or IZO. However, the second electrode 150 may be a metal thin film that is thin enough to transmit light. The lower surface of the second electrode 150 is a light extraction surface 150a. The anode has a work function higher than that of the cathode by selecting a material having a higher work function than that of the cathode or by performing a treatment such as activation.

In the case of Example 1, a part of the light traveling from the light emitting layer toward the second electrode 150 is radiated from the light extraction surface 150a through the second electrode 150.

On the other hand, the light traveling from the light emitting layer toward the first electrode 130 enters the optical path changing layer 120 from the first electrode 130 and then enters the light transmitting substrate 110 from the optical path changing layer 120. reflect. A part of this light is then radiated from the light extraction surface 150a through the transparent substrate 110, the optical path changing layer 120, the first electrode 130, the organic functional layer 140, and the second electrode 150 in this order. Here, the direction of light obliquely incident on the optical path changing layer 120 is changed to a substantially perpendicular direction with respect to the light extraction surface 150 a by the action of the plurality of refractive index changing portions 121. Thereby, the light extraction efficiency is improved as compared with the case where the plurality of refractive index changing portions 121 do not exist.

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

(Example 2)
FIG. 12 is a cross-sectional view of the light emitting device 100 according to the second embodiment. In the light emitting device 100 according to the first embodiment, as illustrated in FIG. 12, the light reflecting film 160 may be disposed between the translucent substrate 110 and the optical path changing layer 120. Note that the lower surface of the translucent substrate 110 and the upper surface of the light reflecting film 160 may be in contact with each other, or even if another layer exists between the translucent substrate 110 and the light reflecting film 160. good. In this case, the same effect as that of the first embodiment can be obtained.

Here, in the case of Example 2, it is preferable that the distance from the light emitting layer to the light reflecting film 160 is an odd multiple of λ / 4 considering the refractive index of the optical path changing layer 120. Accordingly, the light extracted from the light extraction surface 150a after being reflected by the light reflection film 160 and the light extraction surface 150a from the light emitting layer toward the second electrode 150 (without being reflected by the light reflection film 160). Since the phases of the light extracted from each other match each other, it is possible to suppress a decrease in light extraction efficiency due to the cancellation of the light due to the phase shift of each other.

(Example 3)
FIG. 13 is a cross-sectional view of the light emitting device 100 according to the third embodiment. The light emitting device 100 according to Example 3 is different from the light emitting device 100 according to the above-described embodiment in the points described below, and is configured similarly to the light-emitting device 100 according to the embodiment in other points.

The optical path changing layer 120 is disposed not between the translucent substrate 110 and the first electrode 130 but between the organic functional layer 140 and the second electrode 150. That is, the light emitting device 100 includes a light transmissive substrate 110 disposed to face the organic functional layer 140 and a light transmissive first disposed between the light transmissive substrate 110 and the organic functional layer 140. The electrode 130 and the second electrode 150 disposed on the side opposite to the first electrode 130 with respect to the organic functional layer 140 are provided. The optical path changing layer 120 is disposed between the organic functional layer 140 and the second electrode 150, and the light extraction side (that is, the light extraction surface 110a side) that emits light from the light emitting device 100 to the outside is the optical path changing layer. 120 is the light-transmitting substrate 110 side.

More specifically, the optical path changing layer 120 is disposed adjacent to the organic functional layer 140. The optical path changing layer 120 is also disposed adjacent to the second electrode 150. Here, an N-type impurity is introduced into the optical path changing layer 120 so that the voltage can be easily applied from the second electrode 150 to the organic functional layer 140, and the optical path changing layer 120 is a conductive layer. preferable. That is, the optical path changing layer 120 is preferably an N-doped layer.

In the case of Example 3, part of the light traveling from the light emitting layer toward the first electrode 130 is radiated from the light extraction surface 110a through the first electrode 130 and the translucent substrate 110 in this order.

On the other hand, the light traveling from the light emitting layer toward the optical path changing layer 120 passes through the optical path changing layer 120 and is then reflected (totally reflected) by the second electrode 150 which is a reflective electrode. A part of this light is emitted from the light extraction surface 110a through the optical path changing layer 120, the organic functional layer 140, the first electrode 130, and the translucent substrate 110 in this order. Here, the direction of light incident obliquely with respect to the optical path changing layer 120 is changed to a substantially perpendicular direction with respect to the light extraction surface 110 a by the action of the plurality of refractive index changing portions 121. Thereby, the light extraction efficiency is improved as compared with the case where the plurality of refractive index changing portions 121 do not exist.

Thus, also in Example 3, the same effect as the above-described embodiment can be obtained.
Note that the light passing through the photonic crystal tends to have a narrow band. The light that can be extracted from the light extraction surface 110a without going through the photonic crystal from the light emitting layer has a broad spectrum peculiar to the organic EL. On the other hand, since the light reflected by the second electrode 150 passes through the photonic crystal, it becomes a narrow band. Light in which narrow band light is superimposed on light having a broad spectrum is emitted from the light extraction surface 110a.

Next, an example of a process for manufacturing the light emitting device 100 according to Example 3 will be described. 14A and 14B are cross-sectional views illustrating a part of the process of manufacturing the light emitting device 100 according to the third embodiment. First, a light-transmitting conductive film made of a metal oxide conductor such as ITO or IZO is formed on the lower surface of the light-transmitting substrate 110 by sputtering or the like, and patterned by etching to form the first electrode 130. Form. Next, the organic functional layer 140 is formed by depositing an organic material on the lower surface of the first electrode 130. If necessary, the bus line 170 and the partition wall portion 180 are formed at appropriate timings. Next, an organic material such as phthalocyanine-based, azo-based, or NPB is formed on the lower surface of the organic functional layer 140 to form a portion that becomes the base region 122 in the optical path changing layer 120. Next, a first material 151 of the second electrode 150 is formed by depositing a metal material such as Al in a desired pattern on the lower surface of the base region 122 in the optical path changing layer 120 by vapor deposition using a mask or the like. Next, a refractive index changing portion 121 is formed in the base region 122 by irradiating the base region 122 of the optical path changing layer 120 with a light beam such as a laser from the first portion 151 side (FIG. 14A). Here, the first portion 151 of the second electrode 150 functions as a mask for suppressing the influence of light rays on the organic functional layer 140. Next, a metal material such as Al is deposited in a desired pattern on the lower surface of the first portion 151 of the second electrode 150 by vapor deposition using a mask or the like to form the second portion 152 of the second electrode 150. (FIG. 14B). Thus, the second electrode 150 having a laminated structure of the first portion 151 and the second portion 152 is formed. Thereby, the hole formed in the first portion 151 by the irradiation of the light beam is filled with the second portion 152, so that the second electrode 150 can be formed in a desired pattern shape. Note that a sealing layer may be formed on the lower surface of the second electrode 150 as necessary.
When at least one of the organic functional layer 140 and the optical path changing layer 120 is sensitive to the atmosphere, it is desirable to perform film formation and laser irradiation in a vacuum or in a specific gas. This method increases the number of manufacturing steps.
In that case, the first portion 151 is made a uniform film (about 10 nm) thick enough to transmit light, and the laser is condensed and irradiated from above to change the refractive index of the refractive index changing section 121. . After changing the refractive index of the refractive index changing portion 121, the second portion 152 is formed, and a reflective film composed of the first portion 151 and the second portion 152 is formed. By doing so, it is not necessary to perform laser irradiation in a vacuum or in a specific gas, so that the manufacturing process can be reduced accordingly. Even when the laser irradiation is performed between the step of forming the first portion 151 and the step of forming the second portion 152 as described above, the laser irradiation may be performed in a vacuum or in a specific gas. good.

Example 4
FIG. 15 is a cross-sectional view of the light emitting device 100 according to the fourth embodiment. The light emitting device 100 according to the fourth embodiment is different from the light emitting device 100 according to the third embodiment described above (FIG. 13) in the points described below, and is otherwise the same as the light emitting device 100 according to the third embodiment. It is configured.

In the case of Example 4, a dielectric layer 190 is disposed between the first portion 151 and the second portion 152 of the second electrode 150. The dielectric layer 190 is made of a light-transmitting material having a high refractive index. The dielectric layer 190 is made of an organic material such as NPB, for example. The first portion 151 is a thin metal film that is thin enough to transmit light.

In the case of Example 4, a part of the light traveling from the light emitting layer toward the first electrode 130 is radiated from the light extraction surface 110a through the first electrode 130 and the translucent substrate 110 in this order.
On the other hand, the light traveling from the light emitting layer toward the optical path changing layer 120 side passes through the optical path changing layer 120, the first portion 151 of the second electrode 150, and the dielectric layer 190 in this order, and then the second portion of the second electrode 150. Reflected at 152. Part of this light is radiated from the light extraction surface 110a through the dielectric layer 190, the first portion 151, the optical path changing layer 120, the organic functional layer 140, the first electrode 130, and the translucent substrate 110 in this order. The

According to the fourth embodiment, the same effect as that of the third embodiment can be obtained and the plasmon loss generated by the reflection film can be reduced.

(Example 5)
FIG. 16 is a cross-sectional view of the light emitting device 100 according to the fifth embodiment. The light emitting device 100 according to the fifth embodiment is different from the light emitting device 100 according to the first embodiment described above (FIG. 11) in the points described below, and is otherwise similar to the light emitting device 100 according to the first embodiment. It is configured.

The optical path changing layer 120 is disposed not between the translucent substrate 110 and the first electrode 130 but between the organic functional layer 140 and the second electrode 150. Here, an N-type impurity is introduced into the optical path changing layer 120 so that the voltage can be easily applied from the second electrode 150 to the organic functional layer 140, and the optical path changing layer 120 is a conductive layer. preferable. That is, the optical path changing layer 120 is preferably an N-doped layer. Note that the second electrode 150 may be an anode and the first electrode 130 may be a cathode. In this case, it is preferable to introduce a P-type impurity into the optical path changing layer 120 to make the optical path changing layer 120 a P-doped layer.

In the case of Example 5, a part of the light traveling from the light emitting layer toward the second electrode 150 is radiated from the light extraction surface 150a through the second electrode 150.

On the other hand, the light traveling from the light emitting layer toward the first electrode 130 is incident on the translucent substrate 110 from the first electrode 130 and reflected by the light reflecting film 160. A part of this light is then emitted from the light extraction surface 150a through the transparent substrate 110, the first electrode 130, the organic functional layer 140, the optical path changing layer 120, and the second electrode 150 in this order. Here, the direction of light obliquely incident on the optical path changing layer 120 is changed to a substantially perpendicular direction with respect to the light extraction surface 150 a by the action of the plurality of refractive index changing portions 121. Thereby, the light extraction efficiency is improved as compared with the case where the plurality of refractive index changing portions 121 do not exist.

Thus, the same effects as in the first embodiment can be obtained in the fifth embodiment.

In the case of Example 5, the light reflecting film 160 may be disposed between the translucent substrate 110 and the first electrode 130 as in Example 2. Also in this case, for the same reason as in Example 2, it is preferable that the distance from the light emitting layer to the light reflecting film 160 is an odd multiple of λ / 4.

(Example 6)
FIG. 17 is a cross-sectional view of the light emitting device 100 according to the sixth embodiment. The light emitting device 100 according to Example 6 is different from the light emitting device 100 according to Example 4 (FIG. 15) in the points described below, and is configured in the same manner as the light emitting device 100 according to Example 4 in other points. ing.

In the case of Example 6, the high refractive index dielectric layer 190 made of an organic material such as NPB is disposed between the organic functional layer 140 and the first portion 151. Similar to the fourth embodiment, the first portion 151 is a thin metal film that is thin enough to transmit light. The optical path changing layer 120 is disposed between the first portion 151 and the second portion 152.

In the case of Example 6, a part of the light traveling from the light emitting layer toward the first electrode 130 is radiated from the light extraction surface 110a through the first electrode 130 and the translucent substrate 110 in this order.
On the other hand, the light traveling from the light emitting layer toward the dielectric layer 190 side passes through the dielectric layer 190, the first portion 151 of the second electrode 150, and the optical path changing layer 120 in this order, and then the second portion of the second electrode 150. Reflected at 152. A part of this light is emitted from the light extraction surface 110a through the optical path changing layer 120, the first portion 151, the dielectric layer 190, the organic functional layer 140, the first electrode 130, and the translucent substrate 110 in this order. The

Also in Example 6, the same effect as in Example 4 can be obtained.

Next, an example of a process for manufacturing the light emitting device 100 according to Example 6 will be described. 18A and 18B are cross-sectional views illustrating a part of the process of manufacturing the light emitting device 100 according to the sixth embodiment. First, a light-transmitting conductive film made of a metal oxide conductor such as ITO or IZO is formed on the lower surface of the light-transmitting substrate 110 by sputtering or the like, and patterned by etching to form the first electrode 130. Form. Next, the organic functional layer 140 is formed by depositing an organic material on the lower surface of the first electrode 130. If necessary, the bus line 170 and the partition wall portion 180 are formed at appropriate timings. Next, a dielectric layer 190 is formed by depositing an organic material such as NPB on the lower surface of the organic functional layer 140. Next, a first material 151 of the second electrode 150 is formed on the lower surface of the dielectric layer 190 by depositing a metal material such as Al in a desired pattern by vapor deposition using a mask. Next, an organic material such as phthalocyanine-based, azo-based, or NPB is formed on the lower surface of the first portion 151 to form a portion that becomes the base region 122 in the optical path changing layer 120. Next, the refractive index changing portion 121 is formed in the base region 122 by irradiating the base region 122 of the optical path changing layer 120 with a light beam such as a laser from the lower surface side of the optical path changing layer 120 (FIG. 18A). Here, the first portion 151 of the second electrode 150 functions as a mask for suppressing the influence of light rays on the organic functional layer 140. In particular, the refractive index changing portion 121 is formed by irradiating the light path changing layer 120 with light rays in a state where the first portion 151 is disposed beyond the light path changing layer 120 as viewed from the light source. The effect of suppressing the influence on the organic functional layer 140 is high. Also, there is an advantage that this focusing can be easily performed by focusing the irradiated light beam with the first portion 151 made of a thin film metal as a reference. Next, a metal material such as Al is deposited in a desired pattern on the lower surface of the first portion 151 of the second electrode 150 by vapor deposition using a mask or the like to form the second portion 152 of the second electrode 150. (FIG. 18 (b)). Thus, the second electrode 150 composed of the first portion 151 and the second portion 152 is formed. Note that a sealing layer may be formed on the lower surface of the second portion 152 as necessary.

(Example 7)
FIG. 19 is a cross-sectional view of the light emitting device 100 according to the seventh embodiment. The light emitting device 100 according to the seventh embodiment is different from the light emitting device 100 according to the sixth embodiment (FIG. 17) in the points described below, and is configured in the same manner as the light emitting device 100 according to the sixth embodiment in other points. ing.

In Example 7, the second electrode 150 is a thin metal film that is thin enough to transmit light. The second electrode 150 is made of a single metal thin film disposed between the dielectric layer 190 and the optical path changing layer 120, and is not disposed below the optical path changing layer 120. The lower surface of the optical path changing layer 120 is a light extraction surface 120a. Further, a light reflection film 160 is formed on the upper side of the translucent substrate 110. Note that the end portion of the second electrode 150 is drawn to the outside of the light emitting device 100 at the end portion in the extending direction of the partition wall portion 180 (the front side or the back side in FIG. 19). Can be applied with a voltage.

In the case of Example 7, a part of the light traveling from the light emitting layer toward the dielectric layer 190 is emitted from the light extraction surface 120a through the dielectric layer 190, the second electrode 150, and the optical path changing layer 120 in this order. The
On the other hand, part of the light traveling from the light emitting layer toward the first electrode 130 is transmitted through the first electrode 130 and the light-transmitting substrate 110 in this order, and then reflected by the light reflecting film 160, thereby transmitting the light-transmitting substrate 110, The light is emitted from the light extraction surface 120a through the first electrode 130, the organic functional layer 140, the dielectric layer 190, the second electrode 150, and the optical path changing layer 120 in this order.

Also in Example 7, the same effect as in Example 6 can be obtained.

In the case of Example 7 as well, for the same reason as in Example 2, the light reflecting film 160 may be disposed between the translucent substrate 110 and the first electrode 130. Also in this case, for the same reason as in Example 2, it is preferable that the distance from the light emitting layer to the light reflecting film 160 is an odd multiple of λ / 4. Accordingly, the light extracted from the light extraction surface 120a after being reflected by the light reflection film 160 and the light extraction surface 120a from the light emitting layer toward the optical path changing layer 120 side (without being reflected by the light reflection film 160). Decrease in light extraction efficiency due to cancellation of light extracted from each other can be suppressed.

(Example 8)
FIG. 20 is a cross-sectional view of the light emitting device 100 according to the eighth embodiment. The light emitting device 100 according to the eighth embodiment is different from the light emitting device 100 according to the first embodiment (FIG. 11) in the points described below, and is otherwise configured in the same manner as the light emitting device 100 according to the first embodiment. ing.

In the case of Example 8, the optical path changing layer 120 is disposed on the side opposite to the light extraction side (that is, the light extraction surface 150a side) that emits light from the light emitting device 100 to the outside with the organic functional layer 140 as a reference. . Each of the first surface parallel to the organic functional layer 140 and the second surface parallel to the organic functional layer 140 and spaced from the first surface in the direction perpendicular to the organic functional layer 140 , The plurality of refractive index changing portions 121 are arranged at equal intervals at a first interval in the first direction, and are arranged at equal intervals at second intervals in the second direction (refractive index changing portion group shown in FIG. 20). 123, 124). That is, a group (refractive index changing section groups 123, 124, etc.) composed of a plurality of refractive index changing sections 121 arranged in a planar manner is arranged in at least two stages.

By arranging the group of the plurality of refractive index changing portions 121 arranged in a planar manner in this manner in two or more stages, a direction substantially perpendicular to the organic functional layer 140 (and hence on the light extraction surface 150a). The light can be reflected in a direction substantially perpendicular to the direction. In this case, there is no loss due to the reflective film, and thereby the light extraction efficiency can be increased.

Example 9
FIG. 21 is a cross-sectional view of the light emitting device 100 according to the ninth embodiment. The light emitting device 100 according to the ninth embodiment is different from the light emitting device 100 according to the sixth embodiment (FIG. 17) in the points described below, and is configured in the same manner as the light emitting device 100 according to the sixth embodiment in other points. ing.

In the case of Example 9, the first portion 151 of the second electrode 150 is adjacent to the organic functional layer 140. That is, the thin film constituting the cathode is adjacent to the organic functional layer 140. The optical path changing layer 120 is adjacent to the first portion 151.

In the case of Example 9, as in Example 8, the optical path changing layer 120 is the light extraction side (that is, the light extraction surface 110a side) that emits light from the light emitting device 100 to the outside with the organic functional layer 140 as a reference. Located on the opposite side. The configuration of the optical path changing layer 120 is the same as that of the eighth embodiment.

(Example 10)
FIG. 22 is a cross-sectional view of the light emitting device 100 according to the tenth embodiment. In the ninth embodiment, as shown in FIG. 22, a group of a plurality of refractive index changing portions 121 arranged in a planar manner may be arranged in three stages. That is, the light emitting device 100 includes three stages of refractive index changing portion groups 123, 124, and 125. The greater the number of steps of the refractive index changing portion group, the better the light reflection efficiency. Therefore, in the case of the configuration of FIG. 22, the light reflection efficiency can be reliably increased as compared with the case where the refractive index changing portion group has two stages.

More specifically, in the direction perpendicular to the organic functional layer 140, a plurality of refractive index changing portions 121 are arranged at equal intervals at a third interval. That is, a plurality of refractive index changing portion groups are arranged at equal intervals in the vertical direction.

As shown in FIG. 22, the reflective electrode (for example, the second portion 152 of the second electrode 150) may also cover the partition wall portion 180. The same applies to other examples and embodiments.

(Example 11)
FIG. 23 is a cross-sectional view of the light emitting device 100 according to the eleventh embodiment. As shown in FIG. 23, a group of a plurality of refractive index changing sections 121 arranged in a planar manner may be arranged in four or more stages (for example, six stages). That is, the light emitting device 100 includes six stages of refractive index changing portion groups 123, 124, 125, 126, 127, and 128. By arranging the refractive index changing portion groups in four or more stages, the light reflection efficiency can be further increased.

Note that, as shown in FIG. 23, the partition wall portion 180 may be buried in the optical path changing layer 120. The same applies to the other embodiments.

Example 12
FIG. 24 is a cross-sectional view of the light emitting device 100 according to the twelfth embodiment. The light emitting device 100 according to Example 12 is different from the light emitting device 100 according to Example 9 (FIG. 21) in the points described below, and is configured in the same manner as the light emitting device 100 according to Example 9 in other points. ing.

In the case of Example 12, the second electrode 150 does not have the first portion 151 (FIG. 21) and is disposed only on the lower surface side of the optical path changing layer 120. According to the twelfth embodiment, the same effect as the ninth embodiment can be obtained.

(Example 13)
FIG. 25 is a cross-sectional view of the light emitting device 100 according to Example 13. The light-emitting device 100 according to Example 13 is different from the light-emitting device 100 according to Example 11 (FIG. 23) in the points described below, and is otherwise configured in the same manner as the light-emitting device 100 according to Example 11. ing.

In the case of the thirteenth embodiment, the plurality of refractive index changing portions 121 are in the first direction, the second direction, and the organic functional layer 140 in the region R11 having the curved surface S11 facing the light extraction side (that is, the light extraction surface 110a side). They are arranged at equal intervals in the direction perpendicular to the surface.

Here, if the surface facing the light extraction surface 110a in the region R11 is a plane parallel to the light extraction surface 110a, the interface between the first electrode 130 and the translucent substrate 110, the translucent substrate, or the like. The light reflected at a certain angle at the interface between the light emitting space 110 and the light emitting space is reflected at the same angle by the second portion 152 of the second electrode 150 and attenuates while repeating these reflections. In order to suppress the occurrence of such behavior, a plurality of refractive index changing portions 121 are arranged at regular intervals in a region R11 having a curved surface S11 facing the light extraction surface 110a. Thus, the light reflected at a certain angle at the interface between the first electrode 130 and the translucent substrate 110 or at the interface between the translucent substrate 110 and the light emission space is composed of the plurality of refractive index changing portions 121. Since light can be reflected at different angles depending on the photonic crystal, light extraction efficiency can be improved.

Note that, as shown in FIG. 25, the first portion 151 of the second electrode 150 may cover a portion of the partition wall portion 180 that protrudes from the organic functional layer 140 toward the second portion 152 side. In addition, the first portion 151 and the second portion 152 of the second electrode 150 may be connected to each other through the through hole 210.

(Example 14)
FIG. 26 is a cross-sectional view of the light emitting device 100 according to Example 14. The light-emitting device 100 according to Example 14 is different from the light-emitting device 100 according to Example 3 (FIG. 13) in the points described below, and is otherwise configured in the same manner as the light-emitting device 100 according to Example 3. ing.

In the case of Example 14, as in Example 9, the optical path changing layer 120 is the light extraction side (that is, the light extraction surface 110a side) that emits light from the light emitting device 100 to the outside with the organic functional layer 140 as a reference. Located on the opposite side. A plurality of refractive index changing portions 121 are arranged in the base region 122 in a three-dimensional manner with a uniform interval therebetween.

As described above, by arranging the plurality of refractive index changing portions 121 in a three-dimensional manner at a uniform interval, a direction orthogonal to the organic functional layer 140 as much as possible (thus, light) Light can be reflected in a direction that is as orthogonal as possible to the extraction surface 150a. Thereby, the light extraction efficiency can be increased.

More specifically, as in the ninth embodiment, the group of refractive index changing sections 121 (refractive index changing section groups 123, 124, etc.) arranged in a planar manner is arranged in at least two or more stages. Has been placed.

By arranging two or more groups of the plurality of refractive index changing portions 121 arranged in a planar manner in this manner, the organic functional layer 140 can be more reliably secured in the same manner as in the ninth embodiment. Light can be reflected in a direction that is substantially orthogonal (thus, a direction that is also substantially orthogonal to the light extraction surface 110a). Thereby, the light extraction efficiency can be increased.

(Example 15)
FIG. 27 is a cross-sectional view of the light emitting device 100 according to Example 15. The light emitting device 100 according to Example 15 is different from the light emitting device 100 according to the embodiment (FIG. 1) in the points described below, and is otherwise configured in the same manner as the light emitting device 100 according to the embodiment. .

The translucent substrate 110 is disposed to face the organic functional layer 140. The partition wall 180 partitions the organic functional layer 140 into a plurality of regions. In the region sandwiched between the partition wall portion 180 and the translucent substrate 110, the plurality of refractive index changing portions 121 are in the first direction in the region R12 that narrows toward the translucent substrate 110 side. They are arranged at equal intervals in the second direction and the direction perpendicular to the organic functional layer 140.

By arranging the plurality of refractive index changing portions 121 in this way, among the light reflected at the interface between the optical path changing layer 120 and the translucent substrate 110 or the interface between the translucent substrate 110 and the light emission space, In addition, it is possible to increase the probability that the optical path of the light entering the region above the partition wall portion 180 can be changed to the direction extracted from the light extraction surface 110a, that is, the direction orthogonal to the light extraction surface 110a as much as possible.

In FIG. 27, as the region R12, an isosceles trapezoidal cross-sectional region (mesa-shaped region) is illustrated which is wide on the partition wall 180 side and narrow on the translucent substrate 110 side. However, the region R12 may be a triangular cross-sectional region (triangular columnar region) or a polygonal pyramid region in which the partition wall 180 side is the base and the light-transmitting substrate 110 side is the apex.

Note that the physical distance using the wavelength such as λ / 4 as a parameter takes into account the refractive index of each part of the light emitting device. That is, for example, λ / 4 in a material having a refractive index of 1.8 is λ / (4 × 1.8) as an actual distance.

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 (12)

1. An organic functional layer including at least a light emitting layer;
   An optical path changing layer that is disposed on one surface side of the organic functional layer and changes an optical path of light from the light emitting layer;
   With
   The optical path changing layer is
   The base region,
   The refractive index is different from that of the base region, and the refractive index changing portion disposed in the base region;
   Including
   When the peak wavelength of the emission spectrum of the light from the light emitting layer is λ, the dimension of the refractive index changing portion is smaller than λ / 2,
   The plurality of refractive index changing portions are arranged at equal intervals at a first interval in a first direction parallel to the organic functional layer, and are parallel to the organic functional layer and intersect with the first direction. Light emitting devices arranged at equal intervals at second intervals in the second direction.
2. The light emitting device according to claim 1, wherein a distance between centers of the adjacent refractive index changing portions is λ / 2 or more and λ or less.
3. The light emitting device according to claim 1 or 2, wherein the refractive index changing portion has a dimension of λ / 10 or more.
4. The light emitting device according to any one of claims 1 to 3, wherein a refractive index of the refractive index changing portion is smaller than a refractive index of the base region.
5. The refractive index changing portion is a portion where the base region is crystallized, and a refractive index of the refractive index changing portion is larger than a refractive index of the base region. Light-emitting device.
6. The light emitting device according to any one of claims 1 to 3, wherein the refractive index changing portion is a bubble.
7. The light emitting device further includes:
   A translucent substrate disposed to face the organic functional layer;
   A translucent first electrode disposed between the translucent substrate and the organic functional layer;
   A second electrode disposed on the opposite side of the first electrode with respect to the organic functional layer;
   With
   The optical path changing layer is disposed between the translucent substrate and the first electrode,
   The light emitting device according to any one of claims 1 to 6, wherein a light extraction side for emitting light from the light emitting device to the outside is the light transmitting substrate side with respect to the optical path changing layer.
8. The light emitting device further includes:
   A translucent substrate disposed to face the organic functional layer;
   A translucent first electrode disposed between the translucent substrate and the organic functional layer;
   A second electrode disposed on the opposite side of the first electrode with respect to the organic functional layer;
   With
   The optical path changing layer is disposed between the organic functional layer and the second electrode,
   The light emitting device according to any one of claims 1 to 6, wherein a light extraction side for emitting light from the light emitting device to the outside is the light transmitting substrate side with respect to the optical path changing layer.
9. The optical path changing layer is disposed on the side opposite to the light extraction side that emits light from the light emitting device to the outside with respect to the organic functional layer,
   In each of a first surface parallel to the organic functional layer and a second surface parallel to the organic functional layer and spaced from the first surface in a direction perpendicular to the organic functional layer The plurality of refractive index changing portions are arranged at equal intervals at the first interval in the first direction, and are arranged at equal intervals at the second interval in the second direction. A light-emitting device according to claim 1.
10. The light emitting device according to claim 9, wherein a plurality of the refractive index changing portions are arranged at equal intervals at a third interval in a direction perpendicular to the organic functional layer.
11. The plurality of refractive index changing portions are arranged at equal intervals in a region having a curved surface facing the light extraction side in the first direction, the second direction, and a direction perpendicular to the organic functional layer. 9. The light emitting device according to 9.
12. A translucent substrate disposed to face the organic functional layer;
    A partition wall partitioning the organic functional layer into a plurality of regions;
    Further comprising
    In the region sandwiched between the partition wall and the translucent substrate, the plurality of refractive index changing portions are disposed in the region narrowing toward the translucent substrate side, the first direction, and the first The light emitting device according to any one of claims 1 to 8, wherein the light emitting devices are arranged at equal intervals in two directions and a direction perpendicular to the organic functional layer.

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