Organic electroluminescent device and organic electroluminescent display

Abstract

To provide: an organic electroluminescent device in which the light emission loss in a sealing layer on a cathode is reduced and the external quantum efficiency is improved; and an organic electroluminescent display including the same.SOLUTION: An organic electroluminescent device 130 of the present invention includes, on a cathode, a lens layer 133 formed of a plurality of lenses L, and a cover layer 134 covering the lens layer 133. The lenses L are disposed to be aligned in a plane direction S perpendicular to a thickness direction T of the lens layer 133, lens diameters D and thicknesses H of the lenses L are randomly different at respective positions in the plane direction S, and the cover layer 134 is made of a material having a refractive index lower than that of the lenses L.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an organic electroluminescent device and an organic electroluminescent display. [Background technology]

[0002] In recent years, organic electroluminescent displays have been attracting attention as a display device that can replace liquid crystal display elements. The organic electroluminescent elements used in organic electroluminescent displays generally have a total thickness of 1 μm or less, and when a current is injected, they convert electrical energy into light energy and emit light in a planar form, making them ideal for self-luminous display devices.

[0003] An example of a conventional organic electroluminescent device is one in which an anode, a hole transport layer, a light-emitting layer, an electron transport layer, and a cathode are successively formed on a substrate by, for example, a vacuum deposition method. By selectively applying a DC voltage between the anode and the cathode, holes as carriers injected from the anode pass through the hole transport layer, and electrons injected from the cathode pass through the electron transport layer, and each reaches the light-emitting layer, where recombination of electrons and holes occurs, and from here, specific light emission dependent on the molecular skeleton of the organic material that is the light-emitting center constituting the light-emitting layer occurs, and a current flows.

[0004] In a top emission structure in which light is extracted from the top of the device, a part of the light generated in the light emitting layer becomes a plasmon loss mode that occurs at the interface between the anode and the cathode and the organic layers, and another part becomes a waveguide mode that cannot be extracted because it is confined in each organic layer, for example, in the sealing layer on the cathode. From the viewpoint of improving the external quantum efficiency of organic electroluminescent devices, it is required to reduce the light emission loss due to these modes. For example, a technology has been disclosed that reduces the light emission loss due to the plasmon loss mode by replacing the electron transport layer with a layer of semi-crystalline organic material (SCO) having a concave-convex pattern. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide an organic electroluminescent element that reduces luminescence loss in a sealing layer over a cathode and improves external quantum efficiency, and an organic electroluminescent display including the same. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention employs the following means.

[0007] (1) An organic electroluminescent element according to one aspect of the present invention includes a lens layer composed of a plurality of lenses and a cover layer covering the lens layer disposed on a cathode, the plurality of lenses being arranged side by side in a plane direction perpendicular to a thickness direction of the lens layer, the lenses having irregularly different diameters and thicknesses at each position in the plane direction, and the cover layer being made of a material having a lower refractive index than the lenses. Since the lens shape and size are irregularly different at each position of the lens layer, the light incident on the lens layer is reflected in a random direction, and the occurrence of a diffraction pattern in the sealing layer directly below is prevented, so that the light in the guided light mode is reduced. In addition, the material of the cover layer is a low refractive index material that improves light extraction, so that the light extraction from inside the lens is improved. Therefore, the light emission loss due to the guided light mode of the sealing layer on the cathode can be reduced, and the light that can be extracted as the substrate mode can be increased, thereby improving the external quantum efficiency.

[0008] (2) In the organic electroluminescent device according to the above aspect, when the average lens diameter is D1 and the maximum thickness of the plurality of lenses is H, it is preferable that the ratio (H1 / D1) of the maximum thickness H1 to the average lens diameter D1 is 0.5 or more and 1.0 or less. By setting the ratio (H1 / D1) in this range, the light collection rate in the front direction can be increased, and the light extraction from the front can be improved.

[0009] (3) In the organic electroluminescent device according to the above aspect, the lens layer has a thickness of 100 μm in the surface direction. 2 In other words, it is necessary to arrange at least two lenses in one pixel. By setting the number density of the lenses in this range, the irregularity of the lenses can more effectively prevent the occurrence of diffraction patterns. In addition, since alignment is not required when attaching the lens layer from the outside, the alignment yield in the manufacturing process is greatly improved, and the overall yield can be greatly increased.

[0010] (4) In the organic electroluminescent device according to the above aspect, the lens diameter is preferably 1.0 μm or more and 20.0 μm or less. By setting the lens diameter within this range, it becomes possible to arrange at least two lenses for one pixel on the light-emitting layer as described above, and lens alignment becomes unnecessary. It is also important that the lenses are arranged without any gaps, and therefore the lens shape viewed from above is not circular but polygonal.

[0011] (5) In the organic electroluminescent device according to the above aspect, it is preferable that adjacent lenses are disposed with no gap between them. By arranging lenses with irregular diameters and thicknesses without any gaps, it is possible to suppress the occurrence of uneven brightness within a light-emitting pixel or across a surface.

[0012] (6) In the organic electroluminescent element according to the above aspect, a sealing layer for sealing the organic electroluminescent layer is laminated between the organic electroluminescent layer and the lens layer, and the sealing layer is preferably composed of only an inorganic layer made of an inorganic material, or the inorganic layer and an organic layer made of an organic material, which are alternately laminated in the lamination direction.

[0013] (7) An organic electroluminescent display according to an aspect of the present invention includes an organic electroluminescent element having a top emission structure according to the above aspect. This configuration makes it possible to provide an organic electroluminescent display with reduced luminescence loss and improved external quantum efficiency. Effect of the Invention

[0014] According to the present invention, it is possible to provide an organic electroluminescent element in which the luminescence loss in the sealing layer on the cathode is reduced and the external quantum efficiency is improved, and an organic electroluminescent display including the same. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a diagram for explaining a laminated structure of an organic electroluminescent display according to one embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view of an organic electroluminescent element having a top emission structure that constitutes the organic electroluminescent display of FIG. 1. [Diagram 3] FIG. 2 is a diagram showing a modification of the organic electroluminescent display of FIG. 1 in terms of the configuration of the thin film sealing layer. [Figure 4] 4 is a cross-sectional view of an organic electroluminescent element having a top emission structure that constitutes the organic electroluminescent display of FIG. 3. [Diagram 5] (a) Plan view of one pixel, (b) Plan view of one lens, and (c) Plan view of the lens layer. [Figure 6] 2 is a graph showing the measurement results of the angular distribution of luminescence intensity in the configuration of the organic electroluminescent display of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an organic electroluminescent element and an organic electroluminescent display according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the drawings used in the following description may show characteristic parts in an enlarged scale for the sake of convenience in order to make the characteristics easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality. In addition, the materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited to them, and can be appropriately modified and implemented within the scope of the present invention. In addition, although FIGS. 1 to 4 are examples of a top emission structure that extracts light from the top of a substrate, the present invention is not limited to top emission.

[0017] Fig. 1 is a diagram illustrating a layered structure of an organic electroluminescent display 100A (100) according to one embodiment of the present invention. Fig. 2 is a cross-sectional view of an organic electroluminescent element 130A (130) constituting the organic electroluminescent display 100A. The organic electroluminescent display 100A mainly includes a backside barrier section 110, a backplane section 120, an organic electroluminescent element 130A, an adhesive layer 140, and a cover glass (and / or a flexible film (such as an ultraviolet ray cut film)) 150, which are arranged in this order along the layered direction.

[0018] The backside barrier section 110 includes a SiNx / SiOx layer, an organic / resin layer, and a SiNx / SiOx layer in this order. The backplane section 120 includes a substrate, a planarization film (PLN), and a thin film transistor (TFT) in this order.

[0019] The adhesive layer 140 comprises the following sequence: adhesive / touch panel (TP) / barrier layer (OCA) / adhesive layer.

[0020] 2, the organic electroluminescent element 130A includes a front plane portion 131, a thin film sealing layer 132A (132), a lens layer 133, and a cover layer 134, which are arranged in this order along the stacking direction. The front plane portion 131 includes an anode 131A, an organic layer 131E, and a cathode 131C, which are arranged in this order. The organic layer 131E includes, from the anode side to the cathode side, a hole injection layer (HIL), a hole transport layer (HTL), a light-emitting layer, a hole blocking layer (HBL), and an electron transport layer (ETL), which are arranged in this order.

[0021] Thin-film sealing layer 132A is disposed between front plane portion (organic electroluminescent layer) 131 and lens layer 133, and is a sealing layer that seals front plane portion 131. Here, a case is illustrated in which thin-film sealing layer 132A includes only an inorganic layer made of an inorganic material, specifically, only a SiNx / SiOx layer.

[0022] Fig. 3 is a diagram for explaining a laminated structure of an organic electroluminescent display 100B in which the configuration of the thin film sealing layer 132 of the organic electroluminescent display 100A in Fig. 1 is changed. Fig. 4 is a cross-sectional view of an organic electroluminescent element 130B (130) having a top emission structure constituting the organic electroluminescent display 100B in Fig. 3. The thin film sealing layer 132B may be formed by alternately stacking inorganic layers and organic layers made of an organic material in the lamination direction. Here, a case is illustrated in which the thin film sealing layer 132B includes a SiNx / SiOx layer, an organic / resin layer, and a SiNx / SiOx layer in this order.

[0023] The lens layer 133 is composed of a plurality of lenses L formed on the front plane portion 131 (on the cathode 131C). The plurality of lenses L are arranged side by side in a plane direction S perpendicular to a thickness direction (stacking direction) T of the lens layer 133. On the side of the lens layer 133 opposite to the cathode 131C (upper side), portions having surfaces with different curvatures are regarded as different lenses L. It is essential that adjacent lenses L among the plurality of lenses L are in contact with each other.

[0024] The lens diameter D and thickness H of each lens L vary irregularly at each position in the surface direction S. The lens diameter D is the size of each lens in the surface direction S, and is not particularly limited, but may be, for example, 1.0 μm or more and 20.0 μm or less. The lens thickness H is the size of each lens in the thickness direction T, and when the maximum thickness of the plurality of lenses is H1, it is preferable that the ratio (H1 / D1) of the maximum thickness H1 to the average lens diameter D1 is 0.5 or more and 1.0 or less.

[0025] In this embodiment, the case where the lens diameter D and thickness H are irregularly different means that the lens diameter D and thickness H of the lens L are not uniform in plan view from the thickness direction T. For example, 2 The lens diameter D and thickness H of the lenses L included in this region may be defined as being irregularly different when the deviations from the average value of the lens diameter D and thickness H are 0% or more and 50% or less, respectively. Note that the irregularity of the distribution of the lens diameter D and thickness H can be confirmed, for example, from an image (SEM image, etc.) obtained in a plan view from the stacking direction.

[0026] The adjacent lenses are arranged without any gaps. By arranging the lenses having irregular diameters and thicknesses without any gaps, it is possible to suppress the occurrence of uneven brightness within a light-emitting pixel or across a surface.

[0027] Each lens L is made of a material having a refractive index of 1.4 or more and 2.1 or less. Examples of such materials include a siloxane-based polymer, a polymer in which ZrO, TiO2, or the like is dispersed, a mixture of inorganic substances mainly composed of ZrO or TiO2, or a compound containing at least one of them as a main component. In addition, it is preferable that the raw material of the lens L does not contain a solvent.

[0028] When the lens diameter is D and the maximum thickness of the multiple lens thicknesses H is H1, it is preferable that the ratio (H1 / D1) of the maximum thickness H1 to the average lens diameter D1 is 0.5 or more and 1.0 or less. This makes it possible to increase the light collection rate in the front direction and improve the light extraction from the front.

[0029] The lens layer 133 has a thickness of 100 μm in the surface direction S. 2 Each lens layer 133 includes one or more lenses L, and preferably 1.8 to 50 lenses L. In addition, it is preferable that the region of the lens layer 133 that overlaps with the light-emitting layer in the stacking direction includes one or more lenses L, and it is more preferable that four or more lenses L are included.

[0030] The lens layer 133 can be formed by, for example, a molding method using a mold including nanoimprint, an inkjet method, a sputtering method, or the like.

[0031] The cover layer 134 covers the surface of the lens layer 133. The surface of the cover layer 134 opposite to the lens layer 133 (upper side) is flattened. The total thickness of the lens layer 133 and the cover layer 134 is preferably about 10 to 20 μm. The cover layer 134 is made of a material having a lower refractive index than the lens L. Examples of such materials include siloxane-based polymers, methacrylic acid-based polymers, silicone, acrylic polymers, and compounds containing at least one of these as a main component. It is preferable that this filler does not contain a solvent.

[0032] The cover layer 134 is formed, for example, by filling a depletion layer (void) present on the surface of the lens layer 133 using a screen printing method or an inkjet method after the lens layer 133 is formed.

[0033] When a voltage is applied to the organic layer by the two electrodes (anode 131A, cathode 131C) of the front plane section 131, holes and electrons injected into the organic layer from each electrode recombine in the light-emitting layer to generate excitons, which enter an excited state, and generate light as energy released when returning to the ground state (organic electroluminescence (EL) phenomenon).

[0034] The anode 131A is provided on the bottom surface of the organic layer. The anode 131A may also function as a reflective layer. This improves the light emitting efficiency of the organic electroluminescent device. The material of the anode 131A may include a single metal element such as silver (Ag), aluminum (Al), chromium (Cr), titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), molybdenum (Mo), copper (Cu), tantalum (Ta), tungsten (W), platinum (Pt), neodymium (Nd), or gold (Au), or an alloy of these metals.

[0035] As an example, the anode 131A includes a first transparent electrode, a reflective electrode, and a second transparent electrode. The material of the anode is, for example, ITO / Ag alloy / ITO. ITO is a transparent electrode made of indium tin oxide. The Ag alloy used may be an alloy of Ag, Pd, Cu, etc. from the viewpoint of stability, but if the reflectance of the electrode is high, an electrode made of, for example, an Al-based alloy can be used. ITO, Ag alloy, and ITO may have a film thickness of 50 nm, 150 nm, and 10 nm, respectively, but can be appropriately determined according to the device design. It is not necessarily an alloy, and a single metal may be used as long as a stable anode is formed. For example, a structure of ITO / Ag / ITO is also possible.

[0036] The cathode 131C is provided on the top surface of the organic layer. The cathode 131C is provided on the opposite side of the anode 131A. In the case of a top emission structure, it is generally necessary to emit light from the cathode 131C side. Therefore, the cathode 131C needs to be transparent or semi-transparency. When the cathode 131C is formed of a transparent electrode such as ITO or IZO, its film thickness can be about several hundred nanometers, but as long as in-plane conductivity and an equipotential surface can be formed, any film thickness can be selected according to the panel size and resolution. When a metal electrode is used, a thick film thickness is not preferable because it impairs transparency, so the film thickness of the cathode 131C is preferably 15 nm or less. The material of the cathode 131C may be a single metal element such as aluminum (Al), magnesium (Mg), calcium (Ca), or sodium (Na), or an alloy of these metals. More specifically, the material of the cathode can be an alloy of magnesium and silver (MgAg alloy), or an alloy of aluminum (Al) and lithium (Li) (AlLi or a stack of two layers thereof). Any type or composition of electrode can be selected as the cathode 131C.

[0037] The light-emitting layer is provided between the anode 131A and the cathode 131C. The light-emitting layer emits light due to excitons generated by recombination of holes and electrons injected from the anode 131A and the cathode 131C. The light-emitting layer emits light having a wavelength corresponding to the constituent material. For example, when the light-emitting layer emits blue light, the light-emitting layer contains ADN (anthracene dinaphthyl) as a host material and 2.0 mol % of blue-emitting 4,4'-bis[2-{4-(N,N-diphenylamino)phenyl}vinyl]biphenyl (DPAVBi) mixed as a guest material. The thickness of the light-emitting layer is, for example, 30 nm. However, the material and thickness of the light-emitting layer are not particularly limited.

[0038] The hole injection layer functions as a buffer layer to increase the efficiency of hole injection into the light emitting layer and prevent leakage. As an example, the hole injection layer has an aromatic amine structure. The hole injection layer may include any one of 4,4',4''-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA) and 4,4',4''-tris(2-naphthylphenylamino)triphenylamine (2-TNATA). As an example, the thickness of the hole injection layer is 5 nm or more. For example, the thickness of the hole injection layer is 10 nm. The hole injection layer may be doped with a P-type dopant.

[0039] The hole transport layer is provided between the light emitting layer and the anode 131A. The hole transport layer increases the efficiency of hole transport to the light emitting layer. As an example, the hole transport layer has an aromatic amine structure. A representative material for the hole transport layer is bis[(N-naphthyl)-N-phenyl]benzidine (α-NPD). As an example, the thickness of the hole transport layer may be 5 nm or more and 130 nm or less. For example, the thickness of the hole transport layer is 10 nm. The hole transport layer may be doped with a P-type dopant.

[0040] The hole blocking layer prevents holes injected from the hole transport region into the light emitting layer from moving to the electron transport region. The hole blocking layer adjusts the carrier number density of the light emitting layer, and can increase the exciton generation efficiency by the carrier confinement effect. The material of the hole blocking layer can be selected according to the materials of the light emitting layer and the electron transport layer. For example, the hole blocking layer is a material having a lower HOMO level (i.e., a larger ionization potential) than the light emitting layer. In this way, the hole blocking layer can suppress the movement of holes from the light emitting layer and improve the recombination probability. Furthermore, the hole blocking layer is preferably formed of a material whose LUMO level is close to the LUMO level of the electron transport layer. This reduces the charge injection barrier.

[0041] The electron transport layer is provided between the cathode 131C and the light-emitting layer. The electron transport layer increases the efficiency of electron transport to the light-emitting layer. The material of the electron transport layer is not particularly limited as long as the material has electron transport properties. The electron transport layer may include an arylpyridine derivative, a benzimidazole derivative, etc. The electron transport layer may be doped with an N-type dopant. Furthermore, the electron transport layer may include an alkali metal, an alkaline earth metal, a rare earth metal, and their oxides, composite oxides, fluorides, carbonates, etc.

[0042] Adjacent organic electroluminescent elements are partitioned by a pixel-defining film (PDL). By using a black material with high resistivity as the material for the pixel-defining film, it is possible to suppress the decrease in surface reflection even without a polarizing plate. In addition, the organic electroluminescent elements are covered with a thin-film sealing layer, and a substrate such as glass is further bonded over the entire surface of the thin-film sealing layer via an adhesive layer, thereby sealing the organic electroluminescent elements.

[0043] As described above, in the organic electroluminescent display equipped with the organic electroluminescent element of this embodiment, the shape and size of the lens are irregularly different at each position of the lens layer, so that the light incident on the lens layer is reflected in a random direction, and the occurrence of a diffraction pattern in the sealing layer directly below is prevented, so that the light in the guided light mode is reduced. In addition, the material of the cover layer is a low refractive index material that improves light extraction, so that the light extraction from inside the lens is improved. Therefore, the light emission loss due to the guided light mode of the sealing layer on the cathode can be reduced, and the light that can be extracted as the substrate mode can be increased, thereby improving the external quantum efficiency. EXAMPLES

[0044] The effects of the present invention will be more clearly understood by the following examples. Note that the present invention is not limited to the following examples, and can be modified as appropriate without departing from the spirit and scope of the present invention.

[0045] Example 1 Regarding the lenses constituting the lens layer of the organic electroluminescent display of the embodiment, the average lens diameter was set to 1.5 μm, and the maximum lens thickness was set to 1.0 μm. 2 A sample was prepared with 44.4 lenses per unit.

[0046] Example 2 Regarding the lenses constituting the lens layer of the organic electroluminescent display of the embodiment, the average lens diameter was set to 2.0 μm, and the maximum lens thickness was set to 1.5 μm. 2 A sample was prepared with 25.0 lenses per unit.

[0047] Example 3 Regarding the lenses constituting the lens layer of the organic electroluminescent display of the embodiment, the average lens diameter was set to 3.0 μm, and the maximum lens thickness was set to 2.0 μm. 2 A sample was prepared with 11.1 lenses per unit.

[0048] Example 4 Regarding the lenses constituting the lens layer of the organic electroluminescent display of the embodiment, the average lens diameter was set to 5.0 μm, and the maximum lens thickness was set to 3.3 μm. 2 A sample was prepared with 4.0 lenses per unit.

[0049] Example 5 Regarding the lenses constituting the lens layer of the organic electroluminescent display of the embodiment, the average lens diameter was set to 5.0 μm, and the maximum lens thickness was set to 2.6 μm. 2 A sample was prepared with 4.0 lenses per unit.

[0050] Example 6 Regarding the lenses constituting the lens layer of the organic electroluminescent display of the embodiment, the average lens diameter was set to 7.5 μm, and the maximum lens thickness was set to 5.0 μm. 2A sample was prepared with 0.67 lenses per unit.

[0051] Example 7 Regarding the lenses constituting the lens layer of the organic electroluminescent display of the embodiment, the average lens diameter was set to 10.0 μm, and the maximum lens thickness was set to 8.0 μm. 2 A sample was prepared with 0.80 lenses per unit.

[0052] (Reference example) A sample was produced as a reference example in a configuration in which the organic electroluminescent display of Example 1 was not provided with a lens.

[0053] Comparative Example 1 The lenses constituting the lens layer of the organic electroluminescent display of the prior art were microlenses with a lens diameter of 22.0 μm and a thickness of 17.0 μm. 2 The number of lenses per unit was set to 0.2. The other conditions were the same as those in Example 1.

[0054] Comparative Example 2 The lenses constituting the lens layer of the organic electroluminescent display of the prior art were microlenses with a lens diameter of 5.0 μm and a thickness of 2.0 μm. 2 The number of lenses per unit was set to 4.0. The other conditions were the same as in Example 1.

[0055] Comparative Example 3 The lenses constituting the lens layer of the conventional organic electroluminescent display were microlenses with a lens diameter of 5.0 μm and a thickness of 1.5 μm. 2 The number of lenses per unit was set to 4.0. The other conditions were the same as in Example 1.

[0056] Table 1 shows the measurement results of the Reference Example, Examples 1 to 7, Comparative Examples 1 to 3, and the Reference Example.

[0057] [Table 1]

[0058] In Examples 1 to 7, the emission illuminance is improved compared to the Reference Example due to the lens effect that satisfies the range of the H1 / D1 ratio of the present invention (0.5 or more and 1.0 or less). This is because the lenses with random diameters and heights (thicknesses) are arranged without gaps, preventing diffraction. On the other hand, in Comparative Examples 2 and 3, the emission illuminance is lower than that of the Reference Example because the lens configuration has regularity and diffraction occurs.

[0059] Fig. 5(a) is a plan view (top view) of one pixel when the light emitting region is assumed to be a rectangle. Fig. 5(b) is a plan view of a lens constituting the lens layer. Fig. 5(c) is a plan view of the lens layer.

[0060] For lenses and pixels of various sizes, we measured the number of lenses contained in the area overlapping one pixel, i.e., the lens density. The average values ​​of the measurement results are shown in Table 2.

[0061] [Table 2]

[0062] The lens density is 4.0 or less, and the lens diameter D must be smaller than the length P of one side of one pixel. It is preferable that the area of ​​one pixel contains at least one lens.

[0063] Example 8 Measurements were carried out on the organic electroluminescent display of the embodiment described above. The lenses constituting the lens layer had an average lens diameter of 7.5 μm and a maximum lens thickness of 7.0 μm.

[0064] 6 is a graph showing the angular distribution of luminescence intensity measured in the organic electroluminescent display configurations of Example 8 and Reference Example. The horizontal axis of the graph shows the angle between the lamination direction of the organic electroluminescent display and the traveling direction of the light generated in the light-emitting layer. The vertical axis of the graph shows the luminescence intensity.

[0065] Example 8 exhibits a higher emission intensity than the Reference Example over the entire angle range. In the direction of an angle of 0 degrees, i.e., directly above the light-emitting layer, the emission intensity obtained in Example 8 is 110 to 120% of the emission intensity obtained in the Reference Example. In addition, in the direction of an angle of 45 degrees, the emission intensity obtained in Example 8 is approximately 120% of the emission intensity obtained in the Reference Example. [Explanation of symbols]

[0066] 100A, 100B, 100... Organic electroluminescent display 110 Backside barrier section 120 Backplane section 130A, 130B, 130... Organic electroluminescent device 131 Front plane section 131A···Anode 131C···Cathode 131E...Organic layer 132A, 132B, 132...Thin film sealing layer 133 Lens layer 134 Cover layer 140...adhesive layer 150···Cover glass L··· Lens D: Lens diameter D1: Average lens diameter H Lens thickness H1: Maximum lens thickness S...plane direction T: Thickness direction

Claims

1. A lens layer including a plurality of lenses; a cover layer covering the lens layer on the cathode; The plurality of lenses are arranged side by side in a plane direction perpendicular to a thickness direction of the lens layer, the lens diameter and thickness are irregularly different at each position in the plane direction; 13. An organic electroluminescent device, wherein the cover layer is made of a material having a lower refractive index than the lens.

2. When the average value of the lens diameter is D1 and the maximum thickness of the plurality of lenses is H1, 2. The organic electroluminescent device according to claim 1, wherein a ratio (H1 / D1) of the maximum thickness H1 to the average lens diameter D1 is 0.5 or more and 1.0 or less.

3. The lens layer has a thickness of 100 μm in the surface direction. ２ 3. The organic electroluminescent device according to claim 1, further comprising one or more lenses per one element.

4. 3. The organic electroluminescent device according to claim 1, wherein the lens has a diameter of 1.0 μm or more and 20.0 μm or less.

5. 3. The organic electroluminescent device according to claim 1, wherein adjacent lenses are disposed with no gap between them.

6. a sealing layer that seals the organic electroluminescent layer is laminated between the organic electroluminescent layer and the lens layer; 3. The organic electroluminescent device according to claim 1, wherein the sealing layer is formed by alternately stacking, in a stacking direction, an inorganic layer made of an inorganic material alone or an inorganic layer and an organic layer made of an organic material.

7. 3. An organic electroluminescent display comprising the organic electroluminescent element having a top emission structure according to claim 1.

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