Light emitting device

Abstract

To provide a light emitting device that has a higher directivity of light emitted therefrom, while increasing luminous efficacy with a micro-cavity structure.SOLUTION: A light emitting device of the present disclosure has, on a substrate, a first device having in this order a first lower electrode, a first luminous layer emitting light in a first color, a charge generating layer, a second luminous layer emitting the light in a first color, and an upper electrode. The interval between the first luminous layer and the first lower electrode is larger than the interval between the first luminous layer and the second luminous layer.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology of the present disclosure relates to a light-emitting element. [Background technology]

[0002] An organic light-emitting element (also called an organic electroluminescence element (organic EL element)) is an electronic element having a pair of electrodes and an organic compound layer disposed between these electrodes. By injecting electrons and holes from the pair of electrodes, excitons of the light-emitting organic compound in the organic compound layer are generated, and when the excitons return to the ground state, the organic light-emitting element emits light. Recent progress in organic light-emitting elements has been remarkable, with progress being made in lowering driving voltages, diversifying emission wavelengths, achieving high-speed response, and making light-emitting devices thinner and lighter.

[0003] As a technique for achieving high efficiency in organic light-emitting devices, a method of forming an organic layer for each color using a metal mask, photolithography, or the like (hereinafter referred to as a color-by-color method) is known.

[0004] On the other hand, in order to improve the power consumption of organic light-emitting devices, a tandem-type organic light-emitting device is known in which a charge generation layer is provided between multiple light-emitting layers. When an electric field is applied between the lower electrode and the upper electrode, carriers are generated in the charge generation layer, and the carriers are supplied to each light-emitting unit. This allows the light-emitting layer included in each light-emitting unit to emit light efficiently.

[0005] Patent Document 1 describes an organic light-emitting device in which a light-emitting layer is formed by a coating method. Patent Document 1 describes an organic light-emitting device having a first light-emitting unit and a second light-emitting unit between a first electrode and a second electrode, and having a charge generation layer between the light-emitting units. Patent Document 1 also describes that the thickness of the layer between the light-emitting layer of the first light-emitting unit and the light-emitting layer of the second light-emitting unit is made larger than the thickness between the first light-emitting layer and the first electrode, thereby increasing the light-emitting efficiency by the microcavity effect. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 9,209,422 Summary of the Invention [Problem to be solved by the invention]

[0007] In recent years, organic light-emitting elements have also been used in display panels for Augmented Reality (hereinafter referred to as AR panels), but for AR panels, panels with stronger directivity of emitted light are preferred. In order to increase the directivity of light emitted by an organic light-emitting element, it is better for the interference order of the microcavity structure used in the organic light-emitting element to be large. However, in the organic light-emitting element of Patent Document 1, it was found that when the interference order is large, the relationship in which the distance between the light-emitting layer of the first light-emitting unit and the light-emitting layer of the second light-emitting unit is larger than the distance between the first light-emitting layer and the first electrode does not hold.

[0008] The technology of the present disclosure has been made in consideration of the above problems, and provides a light-emitting element that has a microcavity structure to improve light emission efficiency and has higher directivity of emitted light. [Means for solving the problem]

[0009] In order to achieve the above object, the light-emitting device according to the present disclosure includes a first lower electrode, a first light-emitting layer that emits light of a first color, a charge generating layer, a second light-emitting layer that emits light of the first color, and a second light-emitting layer that emits light of the first color. The light-emitting element includes a first element having, in this order, a first light-emitting layer, a first lower electrode, and an upper electrode, and the distance between the first light-emitting layer and the first lower electrode is greater than the distance between the first light-emitting layer and the second light-emitting layer. Effect of the Invention

[0010] According to the technique of the present disclosure, it is possible to provide a light-emitting element that has a microcavity structure to improve the light-emitting efficiency and has higher directivity of emitted light. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating a schematic structure of a light-emitting element according to a first embodiment. [Diagram 2] 4A and 4B are diagrams illustrating driving of a light-emitting element according to an embodiment. [Diagram 3] 4A and 4B are diagrams illustrating light emission characteristics of a light emitting element according to an embodiment. [Figure 4] FIG. 6 is a diagram illustrating a schematic structure of a light-emitting element according to a second embodiment. [Diagram 5] FIG. 13 is a diagram illustrating a schematic structure of a light-emitting element according to a third embodiment. [Figure 6] FIG. 13 is a diagram illustrating a schematic structure of a light-emitting element according to a third embodiment. [Figure 7] FIG. 13 is a diagram illustrating a schematic structure of another light-emitting element according to the third embodiment. [Figure 8] FIG. 13 is a diagram illustrating a schematic structure of still another light-emitting element according to the third embodiment. [Figure 9] FIG. 1 illustrates an example of a display device according to an embodiment. [Figure 10] 1 is a diagram illustrating an example of an imaging device and an electronic device according to an embodiment. [Figure 11] FIG. 1 illustrates an example of a display device according to an embodiment. [Figure 12] 1 is a diagram showing an example of an automobile having a lighting device and a lamp according to an embodiment; [Figure 13] FIG. 2 is a diagram illustrating an example of a wearable device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Note that the present disclosure is not limited to the following embodiment, and can be modified as appropriate without departing from the gist of the present disclosure. In addition, in the drawings described below, parts having the same functions are given the same reference numerals, and their description may be omitted or simplified.

[0013] First Embodiment FIG. 1 is a cross-sectional view illustrating an example of a first subpixel 100a, a second subpixel 100b, and a third subpixel 100c of a light-emitting element 1 according to this embodiment.

[0014] Here, the substrate 101 side is considered to be the bottom and the opposite side to the substrate 101 is considered to be the top. In the light-emitting element 1 of FIG. 1, the lower electrodes 102a to 102c, the first organic layer 103, the second organic layer 104, the first light-emitting layers 105a to 105c, and the third organic layer 106 are arranged in this order on the substrate 101. Furthermore, the light-emitting element 1 is arranged in the following order on the third organic layer 106: the charge generating layer 107, the fourth organic layer 108, the second light-emitting layers 109a to 109c, the fifth organic layer 110, the upper electrode 111, and the protective layer 112. Furthermore, as shown in the figure, an insulating layer 113 is provided to cover both ends of the lower electrode 102a, and the insulating layer 113 is also called a pixel separation film or a bank. Similarly, an insulating layer is provided to cover both ends of the lower electrodes 102b and 102c.

[0015] Here, the first subpixel 100a is an example of a first element, the lower electrode 102a corresponds to a first lower electrode, the first light-emitting layer 105a corresponds to a first light-emitting layer that emits light of a first color, and the second light-emitting layer 109a corresponds to a second light-emitting layer that emits light of a first color. The second subpixel 100b is an example of a second element, the lower electrode 102b corresponds to a second lower electrode, the first light-emitting layer 105b corresponds to a third light-emitting layer that emits light of a second color, and the second light-emitting layer 109b corresponds to a fourth light-emitting layer that emits light of a second color.

[0016] In the light emitting element 1 of this embodiment, the first light emitting layers 105a to 105c and the second light emitting layer 109 are formed by a so-called color-coded method. That is, for example, an organic layer is formed for each color using a metal mask, photolithography, or the like. As a result, the first light emitting layers 105a to 105c emit light of different colors. Also, the second light emitting layers 109a to 109c also emit light of different colors. Also, in this embodiment, at least one of the first organic layer 103, the second organic layer 104, the third organic layer 106, the fourth organic layer 108, and the fifth organic layer 110 is formed by a color-coded method.

[0017] The light-emitting element 1 of the present embodiment is a so-called tandem-type light-emitting element in which a charge generation layer is provided between a plurality of light-emitting layers, and has a charge generation layer 107. The charge generation layer 107 is a layer that generates holes and electrons by applying a voltage between a lower electrode and an upper electrode. The charge generation layer 107 contains a compound that easily accepts electrons from other organic compounds. For example, the charge generation layer 107 is formed by combining an alkali metal with a compound having a lowest unoccupied molecular orbital level energy of −5.0 eV or less, and can function as a charge generation layer. The alkali metal constituting the charge generation layer 107 may be Li, and Li may be used as a simple metal, as a part of a compound, or as a part of an organometallic complex.

[0018] The compound having a lowest unoccupied molecular orbital level energy of −5.0 eV or less used in the charge generation layer 107 may be, but is not limited to, a hexaazatriphenylene compound, a radialene compound, hexafluoroquinodimethane, etc. The lowest unoccupied molecular orbital level energy is low enough to extract an electron from the highest occupied molecular orbital (HOMO) of the alkali metal, thereby enabling charge generation.

[0019] As a result, positive and negative charges are generated in the charge generation layer 107, and the charge generation layer 107 can supply positive or negative charges to layers above and below the charge generation layer 107. In other words, when an electric field is applied between the lower electrode and the upper electrode, carriers are generated in the charge generation layer 107 and the carriers are supplied to the first light-emitting layers 105a to 105c and the second light-emitting layers 109a to 109c, allowing both light-emitting layers to emit light efficiently.

[0020] The light emitting element 1 of the present embodiment is configured so that the sets of the first light emitting layers 105a-105c and the second light emitting layers 109a-109c emit the same color by adopting a color-coded method. For example, the set of the first light emitting layer 105a and the second light emitting layer 109a may be configured to emit red light, the set of the first light emitting layer 105b and the second light emitting layer 109b may be configured to emit green light, and the set of the first light emitting layer 105c and the second light emitting layer 109c may be configured to emit blue light.

[0021] Furthermore, the light emitting element 1 of this embodiment has a so-called microcavity structure. That is, the optical path length from the upper surfaces of the lower electrodes 102a-102c to the light emitting positions of the first light emitting layers 105a-105c corresponding to the lower electrodes 102a-102c is denoted by Lr. Also, the phase shift when light with a wavelength λ is reflected at the interface of the lower electrode 102 is denoted by Φr. In this case, Then, the following equation (1) holds: Lr=(2m-(Φr / π))×(λ / 4) ···(1) Here, m is an integer equal to or greater than 0. The optical distances of the first organic layer 103 and the second organic layer 104 can be optimized for each color so as to satisfy the above formula (1). Here, λ may be the dominant wavelength of the light-emitting element 1. The dominant wavelength λ may be the wavelength emitted from the light-emitting element and extracted to the outside of the light-emitting element. In addition, the dominant wavelength λ may be the maximum peak wavelength of the light-emitting material contained in the light-emitting element.

[0022] If the wavelength λ satisfies the formula (1), the light of each color emitted by the light-emitting element 1 is intensified, but even if the wavelength λ is within a range of values ​​shifted by ±λ / 12, the light emitted by the light-emitting element 1 can be intensified. That is, in this embodiment, the wavelength λ that satisfies the following formula (2) may be adopted. Lr=(2m-(Φr / π))×(λ / 4)±λ / 12 ···(2)

[0023] Furthermore, if the optical distance, which is the distance between the light emitting positions of the first light emitting layers 105a-105c and the reflecting surface of the upper electrode 111, is Ls, and the phase shift when light with wavelength λ is reflected at the interface of the upper electrode 111 is Φs, the following formula (3) is established. Note that m' is an integer equal to or greater than 0, and m'=0 in this embodiment. Ls=(2m'-(Φs / π))×(λ / 4)=-(Φs / π)×(λ / 4) ···(3)

[0024] Similarly to formula (1), if the wavelength λ satisfies formula (3), the light emitted by the light-emitting element 1 is intensified, but even if the wavelength λ is within a range of values ​​shifted by ±λ / 12, the light emitted by the light-emitting element 1 can be intensified. That is, in this embodiment, the wavelength λ that satisfies the following formula (4) may be adopted. Ls=(2m'-(Φs / π))×(λ / 4)±λ / 12 =-(Φs / π)×(λ / 4)±λ / 12 ···(4)

[0025] Therefore, for the optical path length L1 between the lower electrodes 202a to 202c and the first light emitting layers 105a to 105c, the condition shown in the following formula (5) is satisfied based on formulas (1) and (3). L1=Lr+Ls=(2m-Φ / π)×(λ / 4) ···(5) Here, Φ is the sum Φr+Φs of the phase shifts when light of wavelength λ is reflected at the interface of lower electrode 102 and the interface of upper electrode 111.

[0026] Furthermore, although the wavelength λ that satisfies formula (5) is most strongly enhanced, the light emitted by the light-emitting element 1 can also be strengthened by using a wavelength λ within a range of values ​​shifted by ±λ / 12. That is, in this embodiment, a wavelength λ that satisfies the following formula (6) may be adopted. L1=Lr+Ls=(2m-Φ / π)×(λ / 4)±λ / 12 (6)

[0027] Although the above describes the case of the first light-emitting layers 105a-105c, the same relationship holds true for the second light-emitting layers 109a-109c. Therefore, by configuring both the first light-emitting layers 105a-105c and the second light-emitting layers 109a-109c as a microcavity structure, the light-emitting element 1 can achieve more efficient light emission than light-emitting elements according to conventional technology.

[0028] [Microcavity effect of the light-emitting device according to this embodiment] In general, a panel with strong directivity is preferable for an AR panel. In order to increase the directivity of the light emitted by the light emitting element 1, it is more preferable that the interference order of the microcavity structure is large.

[0029] Here, the interference order corresponds to the value of m or m' in the above formulas (1) to (6), and the interference orders m and m' are 0 or positive integers. When m=0 or m'=0, the optical path in each of the above formulas takes the minimum positive value that satisfies the formula. In this embodiment, the interference order m between the upper surface of the lower electrode 102a to 105c and the lower surface of the corresponding first light emitting layer 105a to 105c is 1, and the optical path length Lr is 3λ / 4 when the phase shift φ is -π. Also, the interference order m between the upper surface of the lower electrode 102a to 102c and the lower surface of the corresponding second light emitting layer 109a to 109c is 2, and the optical path length Lr is 5λ / 4 when the phase shift φ is -π.

[0030] For example, when the first subpixel 100a is a pixel that emits red light, the distance between the upper surface of the lower electrode 102a and the lower surface of the first light-emitting layer 105a is about 250 nm, the distance between the upper surface of the lower electrode 102a and the second light-emitting layer 109a is about 410 nm, and the distance between the upper surface of the first light-emitting layer 105a and the second light-emitting layer 109a is about 150 nm.

[0031] In addition, as an example, when the second subpixel 100b is a pixel that emits green light, The distance between the upper surface of the electrode 102b and the lower surface of the first light-emitting layer 105b is about 200 nm, the distance between the upper surface of the lower electrode 102b and the lower surface of the second light-emitting layer 109b is about 340 nm, and the distance between the upper surface of the first light-emitting layer 105b and the lower surface of the second light-emitting layer 109b is about 120 nm.

[0032] For example, when the third subpixel 100c is a pixel that emits blue light, the distance between the upper surface of the lower electrode 102c and the lower surface of the first light-emitting layer 105c is about 170 nm, the distance between the upper surface of the lower electrode 102c and the lower surface of the second light-emitting layer 109c is about 280 nm, and the distance between the upper surface of the first light-emitting layer 105c and the lower surface of the second light-emitting layer 109c is about 100 nm.

[0033] Furthermore, as shown in the figure, the thickness between the first light-emitting layer 105a and the lower electrode 102a ("A" in the figure) is thicker than the thickness between the first light-emitting layer 105a and the second light-emitting layer 109a ("B" in the figure). When the order of interference is large, the thickness A between the first light-emitting layer 105a and the lower electrode 102a in FIG. 1 is made thicker than the thickness B between the first light-emitting layer 105a and the second light-emitting layer 109a, thereby enabling the light-emitting element 1 to emit light with high efficiency due to the microcavity effect. The relationship between the lower electrodes 102b, 102c, the first light-emitting layers 105b, 105c, and the second light-emitting layers 109b, 109c is also similar.

[0034] 8 shows cross-sectional views of a first subpixel 600a, a second subpixel 600b, and a third subpixel 600c of a light-emitting element 6 of a conventional technology as a comparative example of the light-emitting element 1 of the present embodiment. As shown in FIG. 8, in the light-emitting element 6, a lower electrode 602a to 602c, a first organic layer 603, a second organic layer 604, a first light-emitting layer 605a, a third organic layer 606, a charge generating layer 607, and a fourth organic layer 608 are formed on a substrate 601 in this order from the substrate 601 side. Furthermore, in the light-emitting element 6, a second light-emitting layer 609a, a fifth organic layer 610, an upper electrode 611, and a protective layer 612 are formed on the fourth organic layer 608 in this order from the substrate 601 side. In addition, in the light-emitting element 6, an insulating layer 613 is provided to cover an end of the lower electrode 602a.

[0035] In the light-emitting element 6, the thickness between the first light-emitting layer 605a and the second light-emitting layer 609a ("B'" in the figure) is thicker than the thickness between the first light-emitting layer 605a and the lower electrode 602a ("A'" in the figure). Therefore, in the light-emitting element 6, the interference order m between the upper surface of the lower electrode 602a and the lower surface of the first light-emitting layer 605a is 0, and the optical path length Lr is λ / 4 when the phase shift φ is -π. Furthermore, the interference order m between the upper surface of the lower electrode 602a and the lower surface of the second light-emitting layer 609a is 0, and the optical path length Lr is 3λ / 4 when the phase shift φ is -π.

[0036] For example, when the first subpixel 600a is a pixel that emits red light, the distance between the upper surface of the lower electrode 602a and the lower surface of the first light-emitting layer 605a is about 80 nm, the distance between the upper surface of the lower electrode 602a and the lower surface of the second light-emitting layer 609a is about 250 nm, and the distance between the upper surface of the first light-emitting layer 605a and the lower surface of the second light-emitting layer 609a is about 150 nm.

[0037] For example, when the second subpixel 600b is a pixel that emits green light, the distance between the upper surface of the lower electrode 602b and the lower surface of the first light-emitting layer 605b is about 60 nm, the distance between the upper surface of the lower electrode 602b and the lower surface of the second light-emitting layer 609b is about 200 nm, and the distance between the upper surface of the first light-emitting layer 605b and the lower surface of the second light-emitting layer 609b is about 120 nm.

[0038] For example, when the third subpixel 600c is a pixel that emits blue light, the distance between the upper surface of the lower electrode 602c and the lower surface of the first light-emitting layer 605c is about 50 nm, the distance between the upper surface of the lower electrode 602c and the lower surface of the second light-emitting layer 609c is about 170 nm, and the distance between the upper surface of the first light-emitting layer 605c and the lower surface of the second light-emitting layer 609c is about 100 nm. It is.

[0039] Therefore, when the order of interference becomes smaller, the relationship that the thickness B' between the first light-emitting layer 605a and the second light-emitting layer 609a is thicker than the thickness A' between the first light-emitting layer 605a and the lower electrode 602a does not hold.

[0040] As described above, according to the light-emitting element 1 of this embodiment, when the interference order between the first lower electrode and the first light-emitting layer and between the first lower electrode and the second light-emitting layer is large, the light-emitting efficiency can be increased due to the microcavity effect.

[0041] In the light-emitting element 1 according to the present embodiment, the interference order m between the upper surface of the lower electrode 102a and the lower surface of the first light-emitting layer 105a is set to 1, but the interference order m may be any number equal to or greater than 1. Similarly, in the light-emitting element 1 according to the present embodiment, the interference order m between the upper surface of the lower electrode 102a and the lower surface of the second light-emitting layer 109a is set to 2, but the interference order m may be any number equal to or greater than 2.

[0042] <Second embodiment> Next, a light emitting device according to a second embodiment will be described. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0043] 2 shows a cross-sectional view illustrating an example of a first subpixel 200a, a second subpixel 200b, and a third subpixel 200c of the light-emitting element 2 according to this embodiment. As shown in the figure, the light-emitting element 2 has a substrate 201, lower electrodes 202a to 202c, a first organic layer 203, and first light-emitting layers 205a to 205c, similar to the light-emitting element 1. Furthermore, the light-emitting element 2 has a third organic layer 206, a charge generating layer 207, a fourth organic layer 208, second light-emitting layers 209a to 209c, a fifth organic layer 210, an upper electrode 211, a protective layer 212, and an insulating layer 213, similar to the light-emitting element 1.

[0044] In the light-emitting element 2 of the present embodiment, reflective layers 215a-215c and optical adjustment layers 216a-216c are further formed on the light-emitting element 1 of the first embodiment. The optical adjustment layers 216a-216c can be formed of insulating layers. The optical adjustment layer 216a is an example of a first optical adjustment layer, and the optical adjustment layer 216b is an example of a second optical adjustment layer.

[0045] In the light-emitting element 2 of the present embodiment, a microcavity structure may be adopted to make the thicknesses of the optical adjustment layers 216a to 216c different for each subpixel. For example, the thickness of the optical adjustment layer 216a may be set so as to satisfy the red interference condition, the thickness of the optical adjustment layer 216b may be set so as to satisfy the green interference condition, and the thickness of the optical adjustment layer 216c may be set so as to satisfy the blue interference condition.

[0046] The optical path length from the upper surface of the reflective layer 215a to the light emitting position of the first light emitting layer 205a is defined as L1a. The optical path length L1a is the sum of the optical distance between the upper surface of the lower electrode 202a and the first light emitting layer 205a, the optical distance of the thickness of the lower electrode 202a, and the optical distance of the thickness of the optical adjustment layer 216a. The optical path length from the upper surface of the reflective layer 215b to the light emitting position of the first light emitting layer 205b is defined as L1b. The optical path length L1b is the sum of the optical distance between the upper surface of the lower electrode 202b and the first light emitting layer 205b, the optical distance of the thickness of the lower electrode 202b, and the optical distance of the thickness of the optical adjustment layer 216b. The optical path length from the upper surface of the reflective layer 215c to the light emitting position of the first light emitting layer 205c is defined as L1c. The optical path length L1c is the sum of the optical distance from the upper surface of the lower electrode 202c to the first light emitting layer 205c, the optical distance through the thickness of the lower electrode 202c, and the optical distance through the thickness of the optical adjustment layer 216c.

[0047] Similarly, the optical path length from the upper surface of the reflective layer 215a to the light emitting position of the second light emitting layer 209a is defined as L2a. The optical path length L2a is the distance between the upper surface of the lower electrode 202a and the second light emitting layer 209a. The optical path length L2c is the sum of the optical distance, the optical distance of the thickness of the lower electrode 202a, and the thickness of the optical adjustment layer 216a. In addition, the optical path length from the upper surface of the reflective layer 215b to the light-emitting position of the second light-emitting layer 209b is L2b. The optical path length L2b is the sum of the optical distance from the upper surface of the lower electrode 202b to the second light-emitting layer 209b, the optical distance of the thickness of the lower electrode 202b, and the thickness of the optical adjustment layer 216b. In addition, the optical path length L2c is the sum of the optical distance from the upper surface of the reflective layer 215c to the light-emitting position of the second light-emitting layer 209c, the optical distance of the thickness of the lower electrode 202c, and the thickness of the optical adjustment layer 216c.

[0048] In this manner, in the light emitting element 2 of this embodiment, an optical resonator structure is provided between the reflective layer 215a and the first light emitting layer 205a, which resonates the light emitted by the first light emitting layer 205a by reflecting it by the reflective layer 215a. In addition, an optical resonator structure is provided between the reflective layer 215b and the first light emitting layer 205b, which resonates the light emitted by the first light emitting layer 205b by reflecting it by the reflective layer 215b. In addition, an optical resonator structure is provided between the reflective layer 215c and the first light emitting layer 205c, which resonates the light emitted by the first light emitting layer 205c. In the light emitting element 2 of this embodiment, the total thickness of the organic layers is reduced by the optical distance of the thicknesses of the lower electrodes 202a to 202c and the optical adjustment layers 216a to 216c corresponding to the lower electrodes 202a to 202c. The thinner the total thickness of the organic layers, the smaller the voltage applied to the organic light emitting element. The total thickness of the organic layers is reduced by the optical distance between the thicknesses of the lower electrodes 202a to 202c and the optical adjustment layers 216a to 216c corresponding to the lower electrodes 202a to 202c, and the driving voltage is suppressed, thereby reducing power consumption.

[0049] For example, in the first embodiment, in the first subpixel 100a, the thickness of the organic layer from the upper surface of the lower electrode 102a to the lower surface of the upper electrode 111 is about 470 nm. In the second subpixel 100b, the thickness of the organic layer from the upper surface of the lower electrode 102b to the lower surface of the upper electrode 111 is about 390 nm, and in the third subpixel 100c, the thickness of the organic layer from the upper surface of the lower electrode 102c to the lower surface of the upper electrode 111 is about 330 nm.

[0050] In this embodiment, in the first subpixel 200a, the thickness of the organic layer from the upper surface of the lower electrode 202a to the lower surface of the upper electrode 211 is about 250 nm. In the second subpixel 100b, the thickness of the organic layer from the upper surface of the lower electrode 202b to the lower surface of the upper electrode 211 is about 230 nm, and in the third subpixel 200c, the thickness of the organic layer from the upper surface of the lower electrode 202c to the lower surface of the upper electrode 211 is about 210 nm.

[0051] In this way, according to the light-emitting device 2 of the present embodiment, the film thickness of each of the organic layers can be made thinner than that of the light-emitting device 1 of the first embodiment. Furthermore, the total film thickness of the organic layers is reduced by the optical distance between the lower electrodes 202a-202c and the optical adjustment layers 216a-216c, and the driving voltage is suppressed, thereby making it possible to further reduce power consumption.

[0052] Furthermore, in this embodiment, when the interference order m from the upper surfaces of the reflective layers 215a-215c to the lower surfaces of the first light emitting layers 205a-205c is 1 and the phase shift φ is -π, the optical path length Lr is 3λ / 4. When the interference order m from the upper surfaces of the reflective layers 215a-215c to the lower surfaces of the second light emitting layers 209a-209c is 2 and the phase shift φ is -π, the optical path length Lr is 5λ / 4.

[0053] For example, when the first subpixel 200a is a pixel that emits red light, the distance between the upper surface of the reflective layer 215a and the lower surface of the first light-emitting layer 205a is about 310 nm, the distance between the upper surface of the reflective layer 215a and the lower surface of the second light-emitting layer 209a is about 490 nm, and the distance between the upper surface of the first light-emitting layer 205a and the lower surface of the second light-emitting layer 209a is about 160 nm.

[0054] For example, when the second subpixel 200b is a pixel that emits green light, the distance between the upper surface of the reflective layer 215b and the lower surface of the first light-emitting layer 205b is about 250 nm, the distance between the upper surface of the reflective layer 215b and the lower surface of the second light-emitting layer 209b is about 400 nm, and the distance between the upper surface of the first light-emitting layer 205c and the lower surface of the second light-emitting layer 209c is about 140 nm.

[0055] For example, when the third subpixel 200c is a pixel that emits blue light, the distance between the upper surface of the reflective layer 215c and the lower surface of the first light-emitting layer 205c is about 210 nm, the distance between the upper surface of the reflective layer 215c and the lower surface of the second light-emitting layer 209c is about 360 nm, and the distance between the upper surface of the first light-emitting layer 205c and the lower surface of the second light-emitting layer 209c is about 120 nm.

[0056] Therefore, in the light-emitting element 2, similarly to the first embodiment, it is found that the thickness A between the first light-emitting layer 205a and the reflective layer 215a is thicker than the thickness B between the first light-emitting layer 205a and the second light-emitting layer 209a.

[0057] Generally, when the interference order is increased to strengthen the directivity of light emitted from a light-emitting element, the total thickness of the organic layers becomes thicker and the driving voltage of the light-emitting element becomes higher. According to the light-emitting element 2 of this embodiment, the total thickness of the organic layers can be reduced by the optical distance between the lower electrodes 202a-202c and the optical adjustment layers 216a-216c, so that the driving voltage of the light-emitting element can be further reduced.

[0058] <Third embodiment> Next, a light emitting device according to embodiment 3 will be described. In the following description, the same components as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0059] 3 is a cross-sectional view showing an example of a first subpixel 300a, a second subpixel 300b, and a third subpixel 300c of the light-emitting element 3 according to this embodiment. As shown in the figure, the light-emitting element 3 has a substrate 301, lower electrodes 302a to 302c, a first organic layer 303, and first light-emitting layers 305a to 305c, similar to the light-emitting element 1. The light-emitting element 3 also has a third organic layer 306, a charge generating layer 307, a fourth organic layer 308, second light-emitting layers 309a to 309c, a fifth organic layer 310, an upper electrode 311, a protective layer 312, and an insulating layer 313, similar to the light-emitting element 1 of the first embodiment. In the light-emitting element 2 of this embodiment, a groove 314 is further formed on the surface of the insulating layer 313 on the organic layer side as a separation structure, in addition to the light-emitting element 1 of the first embodiment.

[0060] Fig. 4 is an enlarged cross-sectional view of the vicinity of the groove 314 in Fig. 3. In the light-emitting element 3 of the present embodiment, a first organic layer 303, a third organic layer 306, a charge generating layer 307, a fourth organic layer 308, a fifth organic layer 310, and an upper electrode 311 are formed inside the groove 314 from the insulating layer 313 side (substrate 301 side).

[0061] The charge generation layer 307 may be configured to be shared by a plurality of sub-pixels. In that case, charges supplied from the charge generation layer 307 may be supplied to adjacent sub-pixels. In order to reduce such leakage current between sub-pixels, a groove 314 is formed in the light-emitting element 3. The thickness of the organic compound layer inside the groove 314 ("E" in the figure) is thinner than the thickness of the organic compound layer outside the groove 314 ("F" in the figure), and the resistance inside the groove is high. As a result, leakage current between adjacent sub-pixels is suppressed, and color mixing between sub-pixels having different emission colors can be suppressed.

[0062] In the light emitting element 3, when the order of interference is increased to strengthen the directivity of the emitted light, the thickness of the organic layer between the lower electrodes 302a to 302c and the charge generating layer 307 becomes thicker, and the groove 31 4 becomes more likely to be filled with an organic layer.

[0063] In the light-emitting element 3, the second organic layer 304 and the first light-emitting layers 305a to 305c are not formed inside the grooves 314 by a coating method. As a result, when the charge generation layer 307 is formed, the grooves 314 are not filled with an organic layer, and the charge generation layer 307 is formed inside the grooves 314. The thickness of the charge generation layer 307 inside the grooves 314 ("C" in the figure) is thinner than the thickness of the charge generation layer 207 in the flat portion outside the grooves 314 ("D" in the figure). As a result, the resistance inside the grooves 314 is increased, and leakage current between adjacent subpixels is suppressed.

[0064] Furthermore, in the groove 314, the fourth organic layer 308 and the fifth organic layer 310 are formed in the groove, thereby preventing the thickness of the organic layer from the charge generation layer 307 to the upper electrode 311 inside the groove 314 from becoming thin. As a result, the leakage current generated between the charge generation layer 307 and the upper electrode 311 can be suppressed.

[0065] Therefore, the light-emitting element 3 according to this embodiment can enhance the directivity of emitted light while suppressing leakage current between subpixels and further suppressing leakage current between the charge generating layer and the upper electrode.

[0066] <Fourth embodiment> Next, a light emitting device according to a fourth embodiment will be described. In the following description, the same components as those in the above-described embodiments are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0067] FIG. 5 is a cross-sectional view showing an example of the first subpixel 400a, the second subpixel 400b, and the third subpixel 400c of the light-emitting element 4 according to this embodiment. As shown in the figure, the light-emitting element 4 has a substrate 401, lower electrodes 402a to 402c, a first organic layer 403, and a first light-emitting layer 405a to 405c, similar to the light-emitting element 2. Similarly to the light-emitting element 2, the light-emitting element 4 has a third organic layer 406, a charge generation layer 407, a fourth organic layer 408, a second light-emitting layer 409a to 409c, a fifth organic layer 410, an upper electrode 411, a protective layer 412, and an insulating layer 413. Similarly to the light-emitting element 2, the light-emitting element 4 has reflective layers 415a to 415c and optical adjustment layers 416a to 416c. In the light-emitting element 4 of this embodiment, a groove 414 is formed on the surface of the insulating layer 413 on the organic layer side as a separation structure, in addition to the light-emitting element 2.

[0068] Fig. 6 is an enlarged cross-sectional view of the vicinity of groove 414 in Fig. 5. In light-emitting element 4, inside groove 414, a first organic layer 403, a first light-emitting layer 405a, a third organic layer 406, a charge generating layer 407, a fourth organic layer 408, a second light-emitting layer 409a, a fifth organic layer 410, and an upper electrode 411 are formed from the insulating layer 413 side (substrate 401 side).

[0069] In the light emitting element 4 of this embodiment, the thickness of the organic layer between the lower electrodes 402a-402c and the corresponding first light emitting layers 405a-405c can be reduced by the optical distance between the lower electrodes 402a-402c and the corresponding optical adjustment layers 416a-416c. As a result, when the charge generating layer 407 is formed, the groove 414 is not filled with the organic layer, and the charge generating layer 407 is formed inside the groove 414. In addition, the fourth organic layer 408, the second light emitting layer 409, and the fifth organic layer 410 are formed inside the groove 414 between the charge generating layer 407 and the upper electrode 411.

[0070] In this manner, by forming the fourth organic layer 408, the second light-emitting layer 409, and the fifth organic layer 410 inside the groove 414, the thickness of the organic layer from the charge generating layer 407 inside the groove 414 to the upper electrode 411 ("G" in the figure) is prevented from becoming thin.

[0071] Therefore, according to the light-emitting element 4 of the present embodiment, the organic layer from the charge generating layer 407 inside the groove 414 to the upper electrode 411 is prevented from becoming thin. It is possible to suppress the leakage current between the charge generating layer and the upper electrode 411. In the light-emitting element 4, the total film thickness of the organic layers can be reduced while increasing the directivity of the light emitted by the light-emitting element 4, and therefore the driving voltage of the light-emitting element can be reduced. Furthermore, the light-emitting element 4 can suppress the leakage current between the charge generating layer and the upper electrode while suppressing the leakage current between the subpixels.

[0072] <Fifth embodiment> Next, a light emitting device according to embodiment 5 will be described. In the following description, the same components as those in the above embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0073] FIG. 7 is a cross-sectional view showing an example of a first subpixel 500a, a second subpixel 500b, and a fifth subpixel 500c of the light-emitting element 5 according to this embodiment. As shown in the figure, the light-emitting element 5 has a substrate 501, lower electrodes 502a to 502c, a first organic layer 503, and a first light-emitting layer 505a to 505c, similar to the light-emitting element 4. Similarly to the light-emitting element 4, the light-emitting element 5 has a third organic layer 506, a charge generating layer 507, a fourth organic layer 508, a second light-emitting layer 509a to 509c, a fifth organic layer 510, an upper electrode 511, a protective layer 512, and an insulating layer 513. Similarly to the light-emitting element 4, the light-emitting element 5 has reflective layers 515a to 515c and optical adjustment layers 516a to 516c. Also, in the light-emitting element 5, a groove 514 is formed on the surface of the insulating layer 513 on the organic layer side as a separation structure.

[0074] In the light-emitting element 5 of this embodiment, a planarization layer 517 is formed in comparison with the light-emitting element 4 of the fourth embodiment, and color filters 518a to 518c corresponding to the sub-pixels 500a to 500c are disposed on the planarization layer 517. The color filters 518a, 518b, and 518c transmit different colors. Note that the color filters 518a, 518b, and 518c may not be provided in the light-emitting element 5.

[0075] Furthermore, microlenses 519a to 519c corresponding to the sub-pixels 500a to 500c are formed on the color filters 518a, 518b, and 518c, respectively. Therefore, according to the light-emitting element 5 of the present embodiment, the leakage current between the charge generating layer 507 and the upper electrode 511 can be suppressed, and the light of each color output from the sub-pixels 500a to 500c can be efficiently extracted by the microlenses 519a to 519c.

[0076] [Structure of organic light-emitting element] The organic light-emitting element of this embodiment is provided by forming an insulating layer, a lower electrode, a functional layer including a light-emitting layer, and an upper electrode on a substrate. A protective layer, a color filter, a microlens, etc. may be provided on the upper electrode. When a color filter is provided, a planarizing layer may be provided between the protective layer. The planarizing layer may be made of acrylic resin, etc. The same applies when a planarizing layer is provided between the color filter and the microlens.

[0077] [substrate] The material of the substrate constituting the organic light-emitting element may be at least one of quartz, glass, silicon, resin, and metal. In addition, a switching element such as a transistor and wiring may be provided on the substrate, and an insulating layer may be provided thereon. As the insulating layer, any material may be used as long as it can form a contact hole so that wiring can be formed between the first electrode and the insulating layer, and insulation from wiring that is not connected can be ensured. For example, resin such as polyimide, silicon oxide, silicon nitride, etc. may be used.

[0078] [electrode] The electrodes of the organic light-emitting element may be a pair of electrodes. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. In addition, the electrode that supplies holes to the light-emitting layer is the anode, and the electrode with a lower potential is the cathode. The electrode that supplies electrons can also be called the cathode.

[0079] The material constituting the anode should have as large a work function as possible. For example, a metal such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, or tungsten, or a mixture containing these metals, can be used for the anode. Alternatively, an alloy combining these metals, or a metal oxide such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), or indium zinc oxide can be used for the anode. Also, a conductive polymer such as polyaniline, polypyrrole, or polythiophene can be used for the anode.

[0080] Any of these electrode materials may be used alone, or two or more of these materials may be used in combination. The anode may be composed of a single layer or multiple layers.

[0081] When the electrode of the organic light-emitting element is configured as a reflective electrode, the electrode material may be, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or an alloy or laminate thereof. The above materials may function as a reflective film without serving as an electrode. When used as a transparent electrode, a transparent conductive layer of oxide such as indium tin oxide (ITO) or indium zinc oxide may be used, but is not limited to these. Photolithography technology may be used to form the electrode.

[0082] On the other hand, the material for the cathode should have a small work function. Examples of the material include alkali metals such as lithium, alkaline earth metals such as calcium, aluminum, titanium, manganese, silver, lead, chromium, and other metals or mixtures containing these metals. Alternatively, alloys combining these metals can be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, zinc-silver, and the like can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials may be used alone or in combination of two or more types. The cathode may have a single layer structure or a multi-layer structure. Among these, it is preferable to use silver, and it is even more preferable to use a silver alloy to reduce the aggregation of silver. As long as the aggregation of silver can be reduced, the ratio of the alloy is not important. For example, the ratio of silver to other metals may be 1:1, 3:1, and the like.

[0083] The cathode may be a top emission element using an oxide conductive layer such as ITO, or a bottom emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but it is more preferable to use a direct current or alternating current sputtering method, etc., since the film coverage is good and the resistance can be easily reduced.

[0084] [Pixel isolation layer] The pixel separation layer is formed of a silicon nitride (SiN) film, a silicon oxynitride (SiON) film, or a silicon oxide (SiO) film formed by chemical vapor deposition (CVD). In order to increase the resistance of the organic compound layer in the in-plane direction, it is preferable that the organic compound layer, particularly the hole transport layer, is formed thinly on the sidewall of the pixel separation layer. Specifically, the thickness of the sidewall can be thinned by increasing the taper angle of the sidewall of the pixel separation layer or the thickness of the pixel separation layer to increase vignetting during deposition.

[0085] On the other hand, it is preferable to adjust the sidewall taper angle and film thickness of the pixel separation layer to such an extent that no voids are formed in the protective layer formed thereon. Since no voids are formed in the protective layer, the occurrence of defects in the protective layer can be reduced. Since the occurrence of defects in the protective layer is reduced, deterioration in reliability such as the occurrence of dark spots and poor continuity of the second electrode can be reduced. It is possible.

[0086] According to this embodiment, even if the taper angle of the sidewall of the pixel separation layer is not steep, it is possible to effectively suppress charge leakage to adjacent pixels. As a result of the study by the inventors of the present application, it was found that the charge leakage can be sufficiently reduced if the taper angle is in the range of 60 degrees or more and 90 degrees or less. The thickness of the pixel separation layer is preferably 10 nm or more and 150 nm or less. In addition, the same effect can be obtained even if the pixel electrode is composed only of a pixel electrode without a pixel separation layer. However, in this case, it is preferable that the thickness of the pixel electrode is half or less than that of the organic layer, or the pixel electrode end is forward tapered to less than 60 degrees, since this reduces short circuits of the organic light-emitting element.

[0087] [Organic compound layer] The organic compound layer of the organic light-emitting element may be formed as a single layer or multiple layers. When multiple layers are included, they may be called hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, or electron injection layer depending on their functions. The organic compound layer is mainly composed of organic compounds, but may also contain inorganic atoms or inorganic compounds. For example, it may contain copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, or the like. The organic compound layer may be disposed between the first electrode and the second electrode, or may be disposed in contact with the first electrode and the second electrode.

[0088] [Protective layer] In the organic light-emitting device of this embodiment, a protective layer may be provided on the second electrode. For example, by bonding glass provided with a moisture absorbent on the second electrode, it is possible to reduce the intrusion of water and the like into the organic compound layer and reduce the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the cathode to reduce the intrusion of water and the like into the organic compound layer. For example, after forming the cathode, the cathode may be transported to another chamber without breaking the vacuum, and a silicon nitride film having a thickness of 2 μm may be formed by the CVD method to serve as a protective layer. A protective layer may be provided using an atomic deposition method (ALD method) after the film formation by the CVD method. The material of the film formed by the ALD method is not limited, and may be silicon nitride, silicon oxide, aluminum oxide, or the like. Silicon nitride may be further formed by the CVD method on the film formed by the ALD method. The film formed by the ALD method may have a smaller thickness than the film formed by the CVD method. Specifically, it may be 50% or less, or even 10% or less.

[0089] [Color Filter] In the organic light-emitting element of this embodiment, a color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on another substrate and then bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer described above using a photolithography technique. The color filter may be made of a polymer.

[0090] [Planarization layer] In the organic light-emitting element of this embodiment, a planarization layer may be provided between the color filter and the protective layer. The planarization layer is provided for the purpose of reducing the unevenness of the layer below. In addition, when the purpose is not limited, the planarization layer may be called a resin layer. The planarization layer may be composed of an organic compound, and may be a low molecular weight or a high molecular weight, but is preferably a high molecular weight.

[0091] The planarization layer may be provided above and below the color filter, and may be made of the same or different materials.Specific examples of the materials include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0092] [Microlens] The organic light-emitting element may have an optical member such as a microlens on its light-emitting side. The microlens may be made of acrylic resin, epoxy resin, or the like. The microlens may be intended to increase the amount of light extracted from the organic light-emitting element and control the direction of the extracted light. The microlens may have a hemispherical shape. When the microlens has a hemispherical shape, among the tangents to the hemisphere, there is a tangent that is parallel to the insulating layer, and the tangent and the hemisphere are the vertices of the microlens. The vertex of the microlens can be determined in the same manner in any cross-sectional view. That is, among the tangents to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the tangent and the semicircle are the vertices of the microlens.

[0093] It is also possible to define the midpoint of the microlens. In the cross section of the microlens, a line segment is imaginary from a point where an arc shape ends to a point where another arc shape ends, and the midpoint of the line segment can be called the midpoint of the microlens. The cross section for determining the vertex and midpoint may be a cross section perpendicular to the insulating layer.

[0094] The microlens has a first surface having a convex portion and a second surface opposite to the first surface. It is preferable that the second surface is disposed closer to the functional layer than the first surface. To achieve such a configuration, it is necessary to form a microlens on the light-emitting element. When the functional layer is an organic layer, it is preferable to avoid processes that result in high temperatures in the manufacturing process. In addition, when the second surface is disposed closer to the functional layer than the first surface, it is preferable that the glass transition temperatures of all organic compounds constituting the organic layer are 100°C or higher, and more preferably 130°C or higher.

[0095] [Opposite substrate] The organic light-emitting device of this embodiment may have an opposing substrate on the planarization layer. The opposing substrate is called an opposing substrate because it is provided at a position corresponding to the above-mentioned substrate. The constituent material of the opposing substrate may be the same as that of the above-mentioned substrate. When the above-mentioned substrate is the first substrate, the opposing substrate can be the second substrate.

[0096] [Organic layer] The functional layers including the light-emitting layer constituting the organic light-emitting device of this embodiment (hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) are formed by the method shown below.

[0097] The organic compound layer constituting the organic light-emitting device of this embodiment can be formed by a dry process such as a vacuum deposition method, an ionization deposition method, a sputtering method, a plasma method, etc. Also, instead of a dry process, a wet process can be used in which a layer is formed by dissolving the compound in an appropriate solvent and applying a known coating method (e.g., spin coating, dipping, casting method, LB method, inkjet method, etc.).

[0098] Here, when the layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When the layer is formed by a coating method, the layer can be formed by combining with a suitable binder resin.

[0099] Examples of binder resins include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, urea resin, etc. Furthermore, these binder resins may be used alone as homopolymers or copolymers, or may be used in combination of two or more types. Furthermore, known additives such as plasticizers, antioxidants, and ultraviolet absorbers may be used in combination as necessary.

[0100] [Pixel circuit] The light-emitting device having the organic light-emitting element of this embodiment may have a pixel circuit connected to the organic light-emitting element. The pixel circuit may be an active matrix type that controls the emission of the first organic light-emitting element and the second organic light-emitting element independently. The active matrix type circuit may be voltage programming or current programming. The drive circuit has a pixel circuit for each pixel. The pixel circuit may have an organic light-emitting element, a transistor that controls the emission luminance of the organic light-emitting element, a transistor that controls the emission timing, a capacitance that holds the gate voltage of the transistor that controls the emission luminance, and a transistor for connecting to GND without passing through the light-emitting element.

[0101] The light emitting device has a display region and a peripheral region arranged around the display region. The display region has a pixel circuit, and the peripheral region has a display control circuit. The mobility of a transistor constituting the pixel circuit may be smaller than the mobility of a transistor constituting the display control circuit. The slope of the current-voltage characteristic of the transistor constituting the pixel circuit may be smaller than the slope of the current-voltage characteristic of the transistor constituting the display control circuit. The slope of the current-voltage characteristic can be measured by the so-called Vg-Ig characteristic. The transistor constituting the pixel circuit is a transistor connected to a light emitting element such as a first organic light emitting element.

[0102] [Pixels] The organic light-emitting element of this embodiment has a plurality of pixels. The pixels have sub-pixels that emit different colors from each other. The sub-pixels may have, for example, RGB emission colors. The pixels emit light in a region also called a pixel aperture. This region is the same as the first region. The pixel aperture may be 15 μm or less, or 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc. The distance between the sub-pixels may be 10 μm or less, or more specifically, it may be 8 μm, 7.4 μm, 6.4 μm.

[0103] The pixels may have a known arrangement in a plan view. For example, the arrangement may be a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the sub-pixels in a plan view may be any known shape. For example, a rectangle, a quadrangle such as a diamond, or a hexagon. Note that the shape of the sub-pixel is considered to be included in the rectangle if it is, for example, close to a rectangle. Therefore, the shape of the sub-pixel may be a shape that is close to any of the known shapes described above. A pixel may be configured by combining the shape of the sub-pixels and the pixel arrangement.

[0104] [Applications of organic light-emitting devices] The organic light-emitting element according to the present embodiment can be used as a component of a display device or a lighting device. Other uses of the organic light-emitting element include an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, and a light-emitting device having a white light source and a color filter.

[0105] The display device may be an image information processing device having an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., an information processing unit that processes the input information, and displays the input image on a display unit.

[0106] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of the touch panel function may be an infrared type, a capacitance type, a resistive film type, or an electromagnetic induction type, and is not particularly limited. The display device may be used in the display unit of a multifunction printer.

[0107] 9 is a schematic diagram showing an example of a display device having the organic light-emitting element according to the above embodiment. The display device 1000 has a tab between an upper cover 1001 and a lower cover 1009. The display device may have a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008. The touch panel 1003 and the display panel 1005 are connected by flexible printed circuits FPCs 1002 and 1004. Transistors are printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position if the display device is a portable device.

[0108] The display device 1000 may have a color filter having red, green, and blue colors. The color filters may be arranged in a delta arrangement of the red, green, and blue colors. The display device 1000 may be used in a display unit of a mobile terminal. In this case, the display device 1000 may have both a display function and an operation function. Examples of the mobile terminal include mobile phones such as smartphones, tablets, and head-mounted displays.

[0109] Moreover, the display device 1000 may be used as a display unit of an imaging device having an optical unit with a plurality of lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. Moreover, the display unit may be a display unit exposed to the outside of the imaging device, or a display unit disposed within a viewfinder. The imaging device may be a digital camera or a digital video camera.

[0110] Next, Fig. 10A shows a schematic diagram illustrating an example of an imaging device having an organic light-emitting element according to the embodiment. The imaging device 1100 may have a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may have the above-mentioned display device. In this case, the display device may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the moving speed of the subject, the possibility that the subject will be blocked by an obstruction, and the like.

[0111] Since the timing suitable for imaging is short, it is better to display information as soon as possible. Therefore, it is preferable to configure a display device with a fast response speed using the organic light-emitting element of the above embodiment. The display device using the organic light-emitting element of the above embodiment can be used more preferably than these devices, such as liquid crystal display devices, which require a high display speed.

[0112] The imaging device 1100 has an optical section (not shown). The optical section has a plurality of lenses, which form an image on an imaging element housed in a housing 1104. The focus of the plurality of lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically. The imaging device may be called a photoelectric conversion device. The photoelectric conversion device can include an imaging method that does not capture images sequentially, but detects the difference from the previous image, cuts out an image from an image that is always recorded, and the like.

[0113] FIG. 10B is a schematic diagram showing an example of an electronic device having an organic light-emitting element according to the embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that recognizes a fingerprint and performs unlocking or the like. An electronic device having a communication unit can also be called a communication device. The electronic device 1200 may further have a camera function by including a lens and an image sensor. An image captured by the camera function is displayed on the display unit. Examples of the electronic device include a smartphone and a notebook computer.

[0114] Next, Fig. 11A shows a schematic diagram illustrating an example of a display device having the organic light-emitting element according to the embodiment. Fig. 11A shows a display device 1300 such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The display unit 1302 has: The organic light-emitting element according to the above embodiment may be used. The display device 1300 has a frame 1301 and a base 1303 that supports a display unit 1302. The base 1303 is not limited to the form shown in FIG. 11A. The lower side of the frame 1301 may also serve as the base. The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0115] FIG. 11B is a schematic diagram showing another example of a display device having an organic light-emitting element according to the embodiment. The display device 1310 of FIG. 11B is configured to be bendable, and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 may have the organic light-emitting element according to the embodiment. The first display unit 1311 and the second display unit 1312 may be one display device without a joint. The first display unit 1311 and the second display unit 1312 can be separated at the bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first display unit and the second display unit may display one image.

[0116] Next, FIG. 12A shows a schematic diagram illustrating an example of a lighting device having an organic light-emitting element according to the above embodiment. The lighting device 1400 may have a housing 1401, a light source 1402, a circuit board 1403, an optical film 1404, and a light diffusion unit 1405. The light source has the organic light-emitting element according to the above embodiment. The optical filter may be a filter that improves the color rendering of the light source. The light diffusion unit can effectively diffuse the light of the light source, such as for lighting up, and deliver the light to a wide range. The optical filter and the light diffusion unit may be provided on the light emission side of the lighting. If necessary, a cover may be provided on the outermost part.

[0117] The lighting device 1400 is, for example, a device that illuminates a room. The lighting device may emit white, neutral white, or any other color from blue to red. It may have a dimming circuit that dims them. The lighting device 1400 may have an organic light-emitting element according to the above embodiment and a power supply circuit connected thereto. The power supply circuit is a circuit that converts AC voltage to DC voltage. Moreover, white has a color temperature of 4200K, and neutral white has a color temperature of 5000K. Moreover, the lighting device 1400 may have a color filter. Moreover, the lighting device 1400 may have a heat dissipation unit. The heat dissipation unit dissipates heat inside the device to the outside of the device, and examples of the heat dissipation unit include metals with high specific heat and liquid silicon.

[0118] 12B is a schematic diagram of an automobile, which is an example of a moving body having the organic light-emitting element according to the embodiment. The automobile has a tail lamp, which is an example of a lamp. The automobile 1500 has a tail lamp 1501, and may be configured to turn on the tail lamp when braking or the like is performed.

[0119] The tail lamp 1501 has an organic light-emitting element according to the above embodiment. The tail lamp may have a protective member for protecting the organic EL element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0120] An automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window may be a transparent display as long as it is not a window for checking the front and rear of the automobile. The transparent display may have an organic light-emitting element according to the above embodiment. In this case, the constituent materials of the electrodes and the like of the organic light-emitting element are made of transparent materials.

[0121] The moving object having the organic light-emitting element according to the embodiment may be a ship, an aircraft, a drone, or the like. The moving object may have a body and a lighting device provided on the body. The lighting device may emit light to notify the user of the position of the body. The lighting device includes the organic light-emitting element according to the above embodiment.

[0122] In addition, the display device having the organic light-emitting element according to the above embodiment can be applied to a system that can be attached as a wearable device such as smart glasses, HMD, smart contacts, etc. The image capturing and display device used in such an application example has an image capturing device capable of photoelectrically converting visible light, and a display device capable of emitting visible light.

[0123] 13A shows glasses 1600 (smart glasses) according to an application example of a display device having the organic light-emitting element of the above embodiment. An imaging device 1602 such as a CMOS sensor or a SPAD is provided on the front side of a lens 1601 of the glasses 1600. In addition, any of the display devices described above is provided on the back side of the lens 1601.

[0124] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the display device according to each embodiment. The control device 1603 also controls the operations of the image capture device 1602 and the display device. The lens 1601 is formed with an optical system for focusing light on the image capture device 1602.

[0125] FIG. 13B shows glasses 1610 (smart glasses) according to another application example of the display device having the organic light-emitting element of the embodiment. The glasses 1610 have a control device 1612. The control device 1612 is equipped with an imaging device corresponding to the imaging device 1602 and a display device. An optical system for projecting light emitted by the display device in the control device 1612 is formed in the lens 1611, and an image is projected onto the lens 1611. The control device 1612 functions as a power source that supplies power to the imaging device and the display device, and controls the operation of the imaging device and the display device. The control device may have a line-of-sight detection unit that detects the line of sight of the wearer. Infrared light may be used for detecting the line of sight. The infrared light emission unit emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit having a light receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. By having a reduction means for reducing light from the infrared light emission unit to the display unit in a planar view, deterioration of image quality is reduced.

[0126] The gaze of the user with respect to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be applied to gaze detection using the image of the eyeball. As an example, a gaze detection method based on a Purkinje image formed by reflection of irradiated light on the cornea can be used. More specifically, the gaze detection process is performed based on the pupil-corneal reflex method. Using the pupil-corneal reflex method, a gaze vector that indicates the direction (rotation angle) of the eyeball is calculated based on the pupil image and the Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0127] The display device having the organic light-emitting element according to the above embodiment may have an imaging device having a light-receiving element, and may control the display image of the display device based on information about the user's line of sight from the imaging device.

[0128] Specifically, the display device determines a first field of view area to which the user gazes and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received by the display device. In the display area of ​​the display device, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0129] The display area may have a first display area and a second display area different from the first display area, and the display device may select an area with a high priority from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received by the display device. The display device may control the resolution of the area with a high priority to be higher than the resolution of areas other than the area with a high priority. In other words, the display device may lower the resolution of an area with a relatively low priority.

[0130] The display device may use AI (Artificial Intelligence) to determine the first field of view area or the area with high priority. The AI ​​may be a model configured to estimate the angle of the line of sight and the distance to an object at the end of the line of sight from an image of the eyeball, using an image of the eyeball and the direction in which the eyeball in the image was actually looking as teacher data. The AI ​​program may be included in the display device, the imaging device, or an external device. If the external device has the AI ​​program, the AI ​​program is transmitted from the external device to the display device via communication.

[0131] When the display device controls display based on visual recognition detection, the display device can be preferably applied to smart glasses further including an imaging device for capturing an image of the outside world. The smart glasses can display captured outside information in real time.

[0132] The disclosure of this embodiment includes the following configuration. (Configuration 1) a first element having, on a substrate, a first lower electrode, a first light-emitting layer that emits light of a first color, a charge generating layer, a second light-emitting layer that emits light of the first color, and an upper electrode, in this order; The distance between the first light-emitting layer and the first lower electrode is greater than the distance between the first light-emitting layer and the second light-emitting layer. A light-emitting device characterized by: (Configuration 2) a second element having, on the substrate, a second lower electrode, a third light-emitting layer emitting light of a second color different from the first color, the charge generating layer, a fourth light-emitting layer emitting light of the second color, and the upper electrode, in this order; The distance between the third light-emitting layer and the second lower electrode is greater than the distance between the third light-emitting layer and the fourth light-emitting layer. 2. The light-emitting device according to configuration 1. (Configuration 3) When the optical path length between the first lower electrode and the first light-emitting layer is L1, and the optical path length between the first lower electrode and the second light-emitting layer is L2, the following formulas (1) and (2) are satisfied: L1=(2m-(Φ / π))×(λ / 4)±(λ / 12)(m≧1) ···(1) L2=(2m-(Φ / π))×(λ / 4)±(λ / 12)(m≧2) ···(2) Here, λ is the dominant wavelength of the light emitted by the first element, Φ is the phase shift when the light of the dominant wavelength λ is reflected at the interface of the first lower electrode, and m is an integer. 3. The light-emitting device according to configuration 1 or 2. (Configuration 4) the first element has a reflective layer and a first optical adjustment layer between the substrate and the first lower electrode, The second element has a reflective layer and a second optical adjustment layer between the substrate and the second lower electrode. 3. The light-emitting device according to configuration 2. (Configuration 5) the first element has an organic layer between the first lower electrode and the charge generating layer, and an insulating layer between the first lower electrode and the organic layer; the insulating layer has a groove on a surface facing the organic layer, The organic layer is not formed in the groove. 5. The light-emitting device according to any one of configurations 1 to 4. (Configuration 6) The light-emitting device according to configuration 5, wherein the organic layer has a plurality of layers, and the thickest layer of the plurality of layers is not formed in at least a portion of the groove. (Configuration 7) The light-emitting element according to configuration 6, wherein the first element has a reflective layer and a first optical adjustment layer between the substrate and the first lower electrode. (Configuration 8) the first element has an insulating layer in contact with an upper surface of the first lower electrode, and at least one organic layer disposed between the charge generating layer and the upper electrode; the insulating layer has a groove on a surface facing the organic layer, 5. The light-emitting device according to any one of configurations 1 to 4, wherein the organic layer is formed in the groove. (Configuration 9) 9. The light-emitting device according to any one of configurations 8, wherein the organic layer has a plurality of layers, and the thickest layer of the plurality of layers is formed at least partially within the groove. (Configuration 10) The light-emitting element according to configuration 9, wherein the first element has a reflective layer and a first optical adjustment layer between the substrate and the first lower electrode. (Configuration 11) 11. The light-emitting device according to configuration 10, wherein the organic layer is not formed in the groove. (Configuration 12) 12. The light-emitting device according to any one of configurations 1 to 11, further comprising a lens on the light-emitting side of the light-emitting device. (Configuration 13) A display device having a plurality of pixels, At least one of the plurality of pixels has a light-emitting element according to any one of configurations 1 to 12 and a transistor connected to the light-emitting element. A display device comprising: (Configuration 14) An optical section having a plurality of lenses; an imaging element that receives light that has passed through the optical unit; a display unit that displays an image captured by the imaging element; having The display unit has the light-emitting element according to any one of configurations 1 to 12. A photoelectric conversion device comprising: (Configuration 15) A display unit having the light-emitting device according to any one of configurations 1 to 12; A housing provided with the display unit; A communication unit provided in the housing for communicating with an external device; 1. An electronic device comprising: (Configuration 16) A light source having the light-emitting element according to any one of configurations 1 to 12; a light diffusing portion or an optical film that transmits light emitted by the light source; A lighting device comprising: (Configuration 17) A lighting device having the light-emitting element according to any one of configurations 1 to 12; An aircraft having the lighting device provided thereon; A moving object comprising: [Explanation of symbols]

[0133] 1 light emitting element, 102a to 102c lower electrodes, 105a to 105c first light emitting layer, 107 charge generating layer, 109a to 109c second light emitting layer

Claims

1. a first element having, on a substrate, a first lower electrode, a first light-emitting layer that emits light of a first color, a charge generating layer, a second light-emitting layer that emits light of the first color, and an upper electrode, in this order; a distance between the first light-emitting layer and the first lower electrode is larger than a distance between the first light-emitting layer and the second light-emitting layer; When the optical path length between the first lower electrode and the first light-emitting layer is L1 and the optical path length between the first lower electrode and the second light-emitting layer is L2, the following formulas (1) and (2) hold: L1=(2m-(Φ / π))×(λ / 4)±(λ / 12)(m≧1) ...(1) L2=(2m-(Φ / π))×(λ / 4)±(λ / 12)(m≧2) ...(2) where λ is the dominant wavelength of the light emitted by the first element, Φ is the phase shift when the light of the dominant wavelength λ is reflected at the interface of the first lower electrode, and m is an integer. A light-emitting element characterized by:

2. a second element having, on the substrate, a second lower electrode, a third light-emitting layer emitting light of a second color different from the first color, the charge generating layer, a fourth light-emitting layer emitting light of the second color, and the upper electrode, in this order; The distance between the third light-emitting layer and the second lower electrode is greater than the distance between the third light-emitting layer and the fourth light-emitting layer. The light-emitting device according to claim 1 .

3. the first element has a reflective layer and a first optical adjustment layer between the substrate and the first lower electrode, The second element has a reflective layer and a second optical adjustment layer between the substrate and the second lower electrode. The light-emitting device according to claim 2 .

4. the first element has an organic layer between the first lower electrode and the charge generating layer, and an insulating layer between the first lower electrode and the organic layer; the insulating layer has a groove on a surface facing the organic layer, The organic layer is not formed in the groove. The light-emitting device according to claim 1 .

5. 5. The light-emitting device according to claim 4, wherein the organic layer has a plurality of layers, and the thickest layer of the plurality of layers is not formed in at least a part of the groove.

6. The light-emitting element according to claim 5 , wherein the first element has a reflective layer and a first optical adjustment layer between the substrate and the first lower electrode.

7. the first element has an insulating layer in contact with an upper surface of the first lower electrode, and at least one organic layer disposed between the charge generating layer and the upper electrode; the insulating layer has a groove on a surface facing the organic layer, The light-emitting device according to claim 1 , wherein the organic layer is formed in the groove.

8. 8. The light-emitting element according to claim 7, wherein the organic layer has a plurality of layers, and the thickest layer of the plurality of layers is formed in at least a part of the groove.

9. The light-emitting element according to claim 8 , wherein the first element has a reflective layer and a first optical adjustment layer between the substrate and the first lower electrode.

10. The light-emitting device according to claim 9 , wherein the organic layer is not formed in the groove.

11. The light-emitting element according to claim 1 , further comprising a lens on the light-emitting side of the light-emitting element.

12. A display device having a plurality of pixels, At least one of the plurality of pixels comprises the light-emitting element according to any one of claims 1 to 11 and a transistor connected to the light-emitting element. A display device characterized by:

13. an optical section having a plurality of lenses; an imaging element that receives light that has passed through the optical unit; a display unit that displays an image captured by the imaging element; and The display unit includes the light-emitting element according to any one of claims 1 to 11. A photoelectric conversion device characterized by:

14. A display unit having the light-emitting element according to any one of claims 1 to 11; a housing provided with the display unit; a communication unit provided in the housing for communicating with an external device; An electronic device comprising:

15. a light source having the light-emitting element according to any one of claims 1 to 11; a light diffusing portion or an optical film that transmits light emitted by the light source; A lighting device comprising:

16. A lighting fixture having the light-emitting element according to any one of claims 1 to 11; an aircraft on which the lighting fixture is provided; A moving object characterized by having:

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