Light emitting element, display device, and method for manufacturing light emitting element

Abstract

The light-emitting element (10) comprises an AN (2), an HTL (3), a CA (7), an ETL (5) and an EML (6), wherein at least a portion of the EML overlaps a portion of one of the HTL and the ETL, and a portion of the EML overlaps a portion of the other of the HTL and the ETL, and when viewed from above, the HTL and the ETL are arranged relative to each other with the EML in between.

Description

Technical Field

[0001] The present disclosure relates to a light emitting element, a display device, and a method for manufacturing a light emitting element. Background Art

[0002] In recent years, the development of self-luminous light-emitting elements using quantum dots or organic light-emitting materials in the light-emitting layer has been actively carried out. Such light-emitting elements are usually manufactured by sequentially stacking the layers constituting the light-emitting element on a substrate in a direction perpendicular to the substrate surface. For example, the light-emitting element described in Patent Document 1 has a structure in which a first electrode, a functional layer including a light-emitting layer, and a second electrode covering the functional layer are sequentially stacked on a substrate.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Publication No. 2007-188779 Summary of the invention

[0006] Problems to be solved by the invention

[0007] Therefore, conventional light-emitting elements generally have a structure in which a functional layer such as an electrode or a carrier transport layer is stacked on the light-emitting layer in a manner in contact with the light-emitting layer. In most cases, the light-emitting element has a pair of electrodes and a pair of carrier transport layers, and has a structure in which one of the pair of carrier transport layers and one of the pair of electrodes are stacked on the light-emitting layer.

[0008] Therefore, in the existing light-emitting element, the injection of carriers and the extraction of light are both performed from the direction perpendicular to the substrate surface (in the same direction, in opposite directions). In the previous light-emitting element, electrodes and carrier transport layers are arranged on the light extraction path for extracting light from the light-emitting layer. Therefore, the existing light-emitting element is affected by the light absorption of the electrodes and carrier transport layers arranged on the above-mentioned light extraction path or the refractive index difference.

[0009] In addition, the electrodes and carrier transport layers arranged on the above-mentioned light extraction path need to be light-transmissive. Therefore, these electrodes and carrier transport layers are restricted by the use of transparent materials. However, it is very difficult to develop materials that simultaneously meet the conductive gas properties and optical properties suitable for carrier injection. In addition, even if such materials can be developed, there are problems such as film making process or cost.

[0010] One aspect of the present disclosure is completed in view of the above-mentioned problems, and its purpose is to provide a light-emitting element, a display device and a method for manufacturing a light-emitting element that have higher freedom in material selection for electrodes and carrier transport layers than before and can improve light extraction efficiency.

[0011] Solutions to Solve Problems

[0012] In order to solve the above-mentioned problems, a light-emitting element involved in one embodiment of the present invention comprises a first electrode, a first carrier transport layer electrically in contact with the above-mentioned first electrode, a second electrode separately arranged from the above-mentioned first electrode, a second carrier transport layer electrically in contact with the above-mentioned second electrode, and a light-emitting layer, at least a part of the above-mentioned light-emitting layer overlaps with a part of the above-mentioned first carrier transport layer, and a part of the above-mentioned light-emitting layer overlaps with a part of the above-mentioned second carrier transport layer, and when viewed from above, the above-mentioned first carrier transport layer and the above-mentioned second carrier transport layer are arranged relative to each other with the above-mentioned light-emitting layer in between.

[0013] In order to solve the above-mentioned problems, a display device according to one embodiment of the present disclosure includes the above-mentioned light-emitting element according to one embodiment of the present disclosure.

[0014] In order to solve the above-mentioned problems, in a method for manufacturing a light-emitting element involved in one embodiment of the present invention, the light-emitting element comprises a first electrode, a first carrier transport layer electrically in contact with the above-mentioned first electrode, a second electrode arranged separately from the above-mentioned first electrode, a second carrier transport layer electrically in contact with the above-mentioned second electrode, and a light-emitting layer, at least a part of the above-mentioned light-emitting layer overlaps with a part of the above-mentioned first carrier transport layer, and a part of the above-mentioned light-emitting layer overlaps with a part of the above-mentioned second carrier transport layer, and when viewed from above, the above-mentioned first carrier transport layer and the above-mentioned second carrier transport layer are arranged opposite to each other with the above-mentioned light-emitting layer in between, and the manufacturing method comprises: a step of forming the above-mentioned first carrier transport layer; a step of forming the above-mentioned second carrier transport layer separately from the above-mentioned first carrier transport layer; and a step of forming the above-mentioned light-emitting layer in a space portion between the above-mentioned first carrier transport layer and the above-mentioned second carrier transport layer when viewed from above.

[0015] Beneficial Effects

[0016] According to one embodiment of the present disclosure, a light-emitting element, a display device, and a method for manufacturing a light-emitting element can be provided, which have a higher degree of freedom in selecting materials for electrodes and carrier transport layers than before and can improve light extraction efficiency.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a perspective view showing a schematic configuration of the main parts of the display device according to Embodiment 1 when viewed from above.

[0019] Figure 2 It means Figure 1 The I-I line shown will Figure 1The display device shown is a cross-sectional view schematically showing the structure of a main part of the display device when the display device is cut.

[0020] Figure 3 This is a cross-sectional view schematically showing the structure of a display device according to Embodiment 1.

[0021] Figure 4 The diagram is a cross-sectional view showing part of a process for manufacturing a light-emitting element in the display device according to Embodiment 1 in order of process steps.

[0022] Figure 5 This is another cross-sectional view showing part of the manufacturing process of the light emitting element in the display device according to Embodiment 1 in order of the process.

[0023] Figure 6 This is another cross-sectional view showing part of the process of manufacturing the light emitting element in the display device according to Embodiment 1 in order of the process.

[0024] Figure 7 This is another cross-sectional view showing part of the process of manufacturing the light emitting element in the display device according to Embodiment 1 in order of the process.

[0025] Figure 8 This is a plan view showing the relationship between pixels and light-emitting regions of the display device according to Embodiment 1.

[0026] Fig. 9 This is a cross-sectional view schematically showing the structure of a main part of the display device described in Patent Document 1.

[0027] Fig.10 Yes means Fig. 9 A top view showing the relationship between pixels and light-emitting areas of a display device shown.

[0028] Fig.11 This is a graph showing the relationship between the ratio of the long side dimension of a pixel to the short side dimension of the pixel and the pixel effective area ratio in the display device according to Embodiment 1.

[0029] Fig.12 This is a perspective view showing a schematic configuration of the main parts of the display device according to Modification 1 of Embodiment 1 when viewed from above.

[0030] Fig.13 This is a perspective view showing a schematic configuration of the main parts of a display device according to Modification 2 of Embodiment 1 when viewed from above.

[0031] Fig.14 It means Figure 1 The I-I line shown will Figure 1Another cross-sectional view schematically showing the structure of the main part of the display device when the display device is cut away.

[0032] Fig.15 This is another cross-sectional view schematically showing the structure of the main part of the display device according to the second embodiment.

[0033] Fig.16 This is a cross-sectional view showing part of the manufacturing process of the light emitting element in the display device involved in Embodiment 2 in order of the process.

[0034] Fig.17 This is a perspective view showing a schematic structure of the main parts of the display device according to Embodiment 3 when viewed from above.

[0035] Fig.18 It means Fig.17 The II-II line shown will Fig.17 The display device shown is a cross-sectional view schematically showing the structure of a main part of the display device when the display device is cut.

[0036] Fig.19 The cross-sectional view shows part of the manufacturing process of the light-emitting element in the display device involved in Embodiment 3 in order of the process.

[0037] Fig. 20 Another cross-sectional view showing part of the manufacturing process of the light-emitting element in the display device according to Embodiment 3 in order of the process.

[0038] Fig.21 It is a plan view schematically showing the structure of the main parts when the light-emitting element involved in Embodiment 4 is viewed from above.

[0039] Fig. 22 It means along Fig.21 The III-III line shown will Fig.21 The light emitting element shown is a cross-sectional view schematically showing the structure of a main part of the light emitting element when the light emitting element is cut.

[0040] Fig.23 It is a plan view schematically showing the structure of the main parts when the light emitting element involved in the modification example of Embodiment 4 is viewed from above.

[0041] Fig.24 This is another plan view schematically showing the structure of the main parts when the light emitting element involved in the modification example of the fourth embodiment is viewed from above.

[0042] Fig.25 This is another plan view schematically showing the structure of the main parts when the light emitting element according to the modification of the fourth embodiment is viewed from above.

[0043] Fig.26 This is another plan view schematically showing the structure of the main parts when the light emitting element according to the modification of the fourth embodiment is viewed from above.

[0044] Fig. 27 This is a cross-sectional view schematically showing the structure of a main part of a display device according to Embodiment 5.

[0045] Fig.28 This is a flowchart showing a part of the manufacturing process of the light-emitting element and the display device involved in Embodiment 5 in order of the process.

[0046] Fig.29 This is a cross-sectional view schematically showing a configuration of a main portion of a display device according to Modification 1 of Embodiment 5.

[0047] Fig.30 This is a cross-sectional view schematically showing the structure of a main part of a display device according to a second variation of the fifth embodiment.

[0048] Fig.31 This is a cross-sectional view schematically showing the structure of a main part of a display device according to a third variation of the fifth embodiment.

[0049] Fig.32 This is a cross-sectional view schematically showing the structure of a main part of a light emitting element according to a fourth variation of the fifth embodiment. DETAILED DESCRIPTION

[0050] [Implementation Method 1]

[0051] Hereinafter, a layer formed in a process before a layer to be compared is referred to as a “lower layer”, and a layer formed in a process after the layer to be compared is referred to as an “upper layer”.

[0052] <Schematic Configuration of Display Device 100 and Light Emitting Element 10 >

[0053] Figure 1 This is a perspective view showing a schematic configuration of a main part of the display device 100 according to the present embodiment when viewed from above. Figure 2 It means use Figure 1 II wire cut shown Figure 1 The display device 100 shown is a cross-sectional view schematically showing the structure of a main part of the display device 100 . Figure 3 is a cross-sectional view showing a schematic structure of a display device 100 according to this embodiment. Figure 1 In FIG. 1 , the upper surface of the display device 100 is shown through the sealing substrate 22 .

[0054] like Figure 1As shown, the display device 100 includes, for example, a red pixel RP, a green pixel GP, and a blue pixel BP. The red pixel RP is provided with a light emitting element 10R that emits red light. The green pixel GP is provided with a light emitting element 10G that emits green light. The blue pixel BP is provided with a light emitting element 10B that emits blue light.

[0055] Here, red light refers to light having a peak emission wavelength in a band between 600 nm and 780 nm. In addition, green light refers to light having a peak emission wavelength in a band between 500 nm and 600 nm. Blue light refers to light having a peak emission wavelength in a band between 400 nm and 500 nm.

[0056] In addition, the light emitting element 10R preferably has a peak emission wavelength in the range of 620 nm to 650 nm. The light emitting element 10G preferably has a peak emission wavelength in the range of 520 nm to 540 nm. The light emitting element 10B preferably has a peak emission wavelength in the range of 440 nm to 460 nm.

[0057] However, this embodiment is not limited to the above structure, and may include a light emitting element that emits light having a peak emission wavelength in a wavelength band other than the above wavelength band.

[0058] Hereinafter, when it is not necessary to distinguish between the light emitting elements 10R, 10G, 10B, the light emitting elements 10R, 10G, 10B are collectively referred to as "light emitting elements 10". In addition, when it is not necessary to distinguish between the pixels RP, GP, BP, the pixels RP, GP, BP are collectively referred to as "pixels P". As described above, the display device 100 includes a plurality of pixels P, and each pixel P includes a light emitting element 10 corresponding to the pixel P.

[0059] In addition, for convenience of description, the anode is referred to as "AN", the hole transport layer is referred to as "HTL", the insulating layer is referred to as "IL", the electron transport layer is referred to as "ETL", the light emitting layer is referred to as "EML", and the cathode is referred to as "CA".

[0060] like Figure 1 as well as Figure 2 As shown, the light emitting element 10 includes AN2, HTL3, IL4, ETL5, EML6, CA7, and a bank BK.

[0061] like Figure 3 As shown, the display device 100 includes a substrate 1 as a support, a light emitting element layer 11 including a plurality of light emitting elements 10 , a sealing resin 21 as a sealing layer, and a sealing substrate 22 .

[0062] like Figure 2As shown, the display device 100 has a structure in which the above-mentioned layers of the light-emitting element 10 are stacked on the substrate 1 as a support body to form a light-emitting element layer 11 including a plurality of light-emitting elements 10. In addition, in the present disclosure, the direction from the substrate 1 side toward the sealing substrate 22 side is referred to as "upward", and the direction from the sealing substrate 22 side toward the substrate 1 side is referred to as "downward".

[0063] like Figure 3 As shown, the sealing resin 21 is provided in a frame shape at the four ends of the display region in the display device 100. The sealing substrate 22 is bonded to the substrate 1 via the sealing resin 21. The sealing substrate 22 covers the plurality of light-emitting elements 10 provided in the light-emitting element layer 11. Thus, the light-emitting element 10 is sealed by the sealing resin 21 and the sealing substrate 22 so that the light-emitting element 10 is not degraded by moisture or oxygen in the atmosphere. As the above-mentioned sealing substrate 22, for example, a glass substrate (sealing glass) can be used.

[0064] Hereinafter, an example is given in which the lower electrode (first electrode) is AN2 and the upper electrode (second electrode) is CA7. However, the present embodiment is not limited thereto, and the lower electrode (first electrode) may be CA7 and the upper electrode (second electrode) may be AN2.

[0065] The substrate 1 is an array substrate. On the substrate 1, a driving circuit including a plurality of driving elements such as TFTs (thin film transistors) (not shown) for driving the light emitting elements 10 is provided as a pixel circuit.

[0066] AN2 (first electrode) is made of a conductive material and injects holes into EML6 through HTL3. AN2 is a common layer shared by each pixel P and is formed in a whole surface on substrate 1 in a manner covering the surface of substrate 1. AN2 is electrically connected to the TFT of substrate 1 (specifically, for example, the drain electrode of the TFT).

[0067] The display device 100 involved in this embodiment is a top emission type display device that emits light generated in EML6 from the side opposite to the substrate 1, and a light reflecting electrode is used as the lower electrode. Therefore, as the above-mentioned conductive material used for AN2, for example, metals commonly used for anodes in the past, such as Al (aluminum), Ag (silver), Mg (magnesium), or alloys of these metals, etc. can be listed. However, in the case where AN2 is the upper electrode, inorganic oxides such as ITO (indium tin oxide) and InGaZnOx (indium gallium zinc oxide) or conductive compounds doped with impurities in these inorganic oxides can also be used as the above-mentioned conductive material. These conductive materials can be used alone or in combination of two or more.

[0068] HTL3 (first carrier transport layer) is a layer that transports holes from AN2 to EML6 and is in electrical contact with AN2. HTL3 is a common layer shared by each pixel P and is formed in a whole surface on AN2 so as to cover the surface of AN2.

[0069] In addition, the HTL 3 has a plurality of convex portions 3a protruding upward. The convex portions 3a are provided to protrude, for example, in a direction perpendicular to the surface of the substrate 1. When viewed from above, the convex portions 3a are formed, for example, in stripes.

[0070] In the display area of ​​the display device 100, when viewed from above, a plurality of pixels P are arranged in a matrix along a horizontal direction (row direction, first direction) and a vertical direction (column direction, second direction) perpendicular to the horizontal direction. Each pixel P is formed in a rectangular shape, for example. When viewed from above, the convex portions 3a are respectively arranged, for example, on a boundary along a vertical direction between pixels P adjacent to each other in the horizontal direction, and are spaced apart from each other along the boundary (in other words, in the vertical direction).

[0071] HTL3 may be opaque. Since HTL3 does not cover the top of EML6, it does not need to be transparent. Therefore, HTL3 may be transparent or opaque. In HTL3, a material suitable for electronic properties can be selected from the materials used in AN2 and EML6. In the case where HTL3 is opaque, the convex portion 3a can be used as a shielding cover to prevent light interference. In addition, in the case where the lower electrode is CA7 and the upper electrode is AN2, HTL3 is preferably transparent, but it does not necessarily have to be transparent.

[0072] The material of HTL3 may be any hole transporting material as long as it can stabilize the transport of holes into EML6, and among these, a material having a high hole mobility is preferred.

[0073] The material of HTL3 can use a known hole transport material. Among them, if a semiconductor material is used as the material of HTL3, the manufacturing method of the TFT backplane in the substrate 1 can be directly applied, and the processing of HTL3 can be easily performed. Therefore, it is advantageous in terms of process. According to the present embodiment, as described above, HTL3 does not cover the top of EML6, so it does not need to be transparent. Therefore, the material of HTL3 can use general semiconductor materials without any problem. In addition, by using a semiconductor material in the material of HTL3, as the carrier density, the hole density can be easily increased, and the resistance of HTL3 can be reduced. As a result, a low-resistance ohmic contact can be obtained. In the present embodiment, there is no need to consider the optical properties of the carrier transport layer, and a low-resistance p-type semiconductor can be used for HTL3.

[0074] As the above-mentioned semiconductor materials for HTL3, for example, Si (silicon), oxide semiconductors (metal oxides), Group IV semiconductors, Group II-VI compound semiconductors, Group III-V compound semiconductors, etc. can be cited. As the above-mentioned oxide semiconductors (metal oxides), for example, MoO3 (molybdenum trioxide), Cr2O3 (chromium oxide), NiO (nickel oxide), WO3 (tungsten trioxide), ITO (indium tin oxide), InGaZnOx (indium gallium zinc oxide), Ga2O3 (gallium oxide), In2O3 (indium oxide), etc. can be cited. In addition, the classification of oxide semiconductors and metal oxides is not necessarily clear, and metal oxides are included and called oxide semiconductors. In addition, even if the material of HTL3 is a metal oxide, it does not matter in terms of obtaining the function of HTL3. As the above-mentioned Group IV semiconductors, for example, Si (silicon), Ge (germanium), etc. can be cited. Examples of the above-mentioned II-VI compound semiconductors include IZO (indium-doped zinc oxide), ZAO (aluminum-doped zinc oxide), ZnO (zinc oxide), MgO (magnesium oxide), ZnMgO (zinc magnesium oxide), ZnS (zinc sulfide), ZnSe (zinc selenide), ZnSSe (zinc sulfide selenide), MgS (magnesium sulfide), MgSe (magnesium selenide), and MgSSe (magnesium sulfide selenide). Examples of the above-mentioned III-V compound semiconductors include AlAs (aluminum arsenide), GaAs (gallium arsenide), InAs (indium arsenide), and AlGaInAs (aluminum gallium indium arsenide) as mixed crystals thereof, AlN (aluminum nitride), GaN (gallium nitride), InN (indium nitride), and AlGaInN (aluminum gallium indium nitride) as mixed crystals thereof, GaP (gallium phosphide), and AlGaInP (aluminum gallium indium phosphide). However, the above-mentioned hole transporting material is only an example, and is not limited to the above-mentioned exemplified materials. These hole transporting materials may be used alone or in combination of two or more.

[0075] In addition, HTL3 may have a function of hindering the transmission of electrons. In this case, the hole transport material is preferably an electron blocking material that prevents the penetration of electrons moving from ETL5. Thus, the recombination efficiency of holes and electrons in EML6 can be improved. In addition, HTL3 may also have a function as a hole injection layer that promotes the injection of holes from AN2 to EML6.

[0076] On the HTL3, a plurality of IL4 are formed in an island shape. On these IL4, ETL5 (second carrier transport layer) is formed in an island shape so as to protrude upwards and face the convex portion 3a in a plan view. ETL5 is formed on the HTL3 via the IL4.

[0077] In this embodiment, IL4 insulates HTL3 from ETL5. ETL5 (second carrier transport layer) is a layer that transports electrons from CA7 to EML6, and is in electrical contact with CA7.

[0078] ETL5 has a shape similar to IL4. IL4 and ETL5 are formed in, for example, an I-shape in a plan view.

[0079] The ETL5 has a longitudinal line portion 5a as a main line portion extending in the longitudinal direction as the extending direction of the convex portion 3a, and a transverse line portion 5b as a branch line portion extending in the transverse direction (in-plane direction) perpendicular to the longitudinal line portion 5a at both ends of the extending direction of the longitudinal line portion 5a in each pixel P. The longitudinal line portion 5a is alternately arranged with the convex portion 3a between adjacent convex portions 3a, for example, in a manner that divides the pixel P into two. The transverse line portions 5b, 5b are respectively arranged at intervals from each other along the transverse boundary (in other words, transversely) between adjacent pixels P in the longitudinal direction when viewed from above.

[0080] Similarly, IL4 has a longitudinal line portion 4a as a main line portion extending in the longitudinal direction as the extending direction of the convex portion 3a in a plan view, and a transverse line portion 4b as a branch line portion located at both ends of the extending direction of the longitudinal line portion 4a in each pixel P and extending in the transverse direction perpendicular to the longitudinal line portion 4a. The longitudinal line portion 4a is alternately provided with the convex portion 3a between adjacent convex portions 3a, for example, in a manner that divides the pixel P into two. The transverse line portions 4b·4b are provided at intervals from each other along the transverse boundary (in other words, transversely) between adjacent pixels P in a plan view, for example, in the longitudinal direction.

[0081] In addition, banks BK are provided at the four corners of the pixel P, and the banks BK have a height higher than the upper surface of the HTL3 and the upper surface of the ETL5. The banks BK insulate the HTL3 and the ETL5 at the four corners of the pixel P. The banks BK are opaque, and together with the convex portion 3a and the horizontal line portions 4b and 5b, function as separation walls that separate the pixels P (in other words, separate the light-emitting elements 10).

[0082] The pixel P is surrounded by the horizontal line portions 4b and 5b, the convex portion 3a, and the bank BK, respectively, in a plan view.

[0083] IL4 is an insulating layer having light transmittance. In addition, IL4 is preferably a transparent insulating layer. As the material of IL4, a known transparent insulating material can be used. As the above-mentioned transparent insulating material, for example, inorganic insulating materials such as SiO2 (silicon oxide), SiN (silicon nitride), SION (silicon oxynitride); organic insulating materials such as silicone resin, epoxy resin, acrylic resin, fluorine resin, etc. can be listed.

[0084] ETL5 is preferably transparent, but not necessarily transparent. In ETL5, a material suitable for electronic properties can be selected from the materials used in CA7 and EML6. In addition, when the lower electrode is CA7 and the upper electrode is AN2, an opaque material is selected as the material of ETL5. When ETL5 is opaque, ETL5 can be used as a shielding cover to prevent interference of light.

[0085] Well-known electron transport materials can be used for ETL5. Among them, if a semiconductor material is used as the material of ETL5, the manufacturing method of the TFT backplane in the substrate 1 can be directly applied as with HTL3, and the processing of ETL5 can be easily performed. Therefore, it is advantageous in terms of process. According to this embodiment, since ETL5 does not cover the top of EML6, it does not need to be transparent. Therefore, for the material of ETL5, general semiconductor materials can be used without problems. In addition, by using a semiconductor material in the material of ETL5, the electron density can be easily increased as a carrier density, and the resistance of ETL5 can be reduced. As a result, a low-resistance ohmic contact can be obtained. As a result, sufficient current can be obtained only by making CA7 electrically contact with at least a portion of ETL5.

[0086] In the present embodiment, it is not necessary to consider the optical characteristics of the carrier transport layer, and a low-resistance n-type semiconductor can be used for the ETL 5 .

[0087] As the semiconductor material used for ETL5, for example, Si, oxide semiconductors (metal oxides), II-VI compound semiconductors, III-V compound semiconductors, IV-IV compound semiconductors, etc. can be listed. As the oxide semiconductor (metal oxide), for example, the above-mentioned MoO3, Cr2O3, NiO, WO3, ITO, InGaZnOx, Ga2O3, In2O3, etc. can be listed. As the II-VI compound semiconductor, for example, the above-mentioned IZO, ZAO, ZnO, MgO, ZnMgO, ZnS, ZnSe, ZnSSe, MgS, MgSe, MgSSe, etc. can be listed. As the III-V compound semiconductor, for example, the above-mentioned AlAs, GaAs, InAs, and AlGaInAs as a mixed crystal thereof; AlN, GaN, InN, and AlGaInN, GaP, AlInGaP, etc. as a mixed crystal thereof can be listed. Examples of the IV-IV group compound semiconductor include semiconductors composed of different elements such as SiGe (silicon germanium) and SiC (silicon carbide). These electron transporting materials may be used alone or in combination of two or more.

[0088] In addition, ETL5 may also have the function of hindering the transport of holes. In this case, the electron transport material is preferably a hole blocking material that prevents the penetration of holes moving from AN2. Thus, the recombination efficiency of holes and electrons in EML6 can be improved. In addition, ETL5 may also have the function of an electron injection layer that promotes the injection of electrons from CA7 to EML6.

[0089] The bank BK can be made of an organic insulating material such as a polyimide resin or an acrylic resin.

[0090] EML6 is a layer containing a light-emitting material, and emits light due to the recombination of electrons transported from CA7 and holes transported from AN2.

[0091] The EML6 is formed in the concave portion CP surrounded by the HTL3, IL4, ETL5 and the bank BK. In other words, the EML6 is formed in the concave portion CP, and the concave portion CP includes the convex portion 3a, IL4, ETL5 and the bank BK in a part of the side wall. When viewed from above, the convex portion 3a and the IL4 and ETL5 are arranged opposite to each other with the EML6 sandwiched therebetween. The light emitting element 10 emits light from the side and bottom of the concave portion CP.

[0092] When viewed from the cross section, the convex portion 3a, IL4 and ETL5 each have a forward tapered shape. More specifically, the convex portion 3a, IL4 and ETL5 each have a trapezoidal cross-sectional shape whose upper end is smaller than the lower end. The side surface of IL4 and the side surface of ETL5 are formed on the same plane.

[0093] As in Figure 2 As shown by the frame F1 shown by the two-dot chain line in FIG. 1 , the EML 6 is formed overlappingly on a part of the HTL 3. A part of the EML 6 is formed overlappingly on a part of the convex portion 3a. Figure 2 As shown by being surrounded by a frame F2 indicated by two-dot chain lines, a part of the EML 6 is formed to overlap a part of the ETL 5 .

[0094] EML6, as a light-emitting material, may include, for example, a nano-sized quantum dot phosphor (hereinafter referred to as "QD"). The above-mentioned QD may use a well-known QD. The above-mentioned QD may, for example, include at least one semiconductor material composed of at least one element selected from the group consisting of Cd (cadmium), S (sulfur), Te (tellurium), Se (selenium), Zn (zinc), In (indium), N (nitrogen), P (phosphorus), As (arsenic), Sb (antimony), aluminum (Al), Ga (gallium), Pb (lead), Si (silicon), Ge (germanium), and Mg (magnesium). In addition, the above-mentioned QD may also be a two-component core type, a three-component core type, a four-component core type, a core-shell type, or a core-multi-shell type. In addition, the above-mentioned QD may include nanoparticles doped with at least one of the above-mentioned elements, and may also have a structure with an inclined composition.

[0095] However, the present embodiment is not limited to the above-mentioned examples, and the EML 6 may include, for example, an organic light-emitting material that emits light of various colors as a light-emitting material instead of the QD.

[0096] As described above, in the case of a QLED (quantum dot light emitting diode) using QD as the light emitting material, the driving current between AN2 and CA7 causes holes and electrons to recombine in EML 6. In addition, light (fluorescence) is emitted in the process of excitons generated thereby migrating from the conduction band energy level of QD to the valence band energy level.

[0097] On the other hand, when the light emitting element 10 is an OLED (organic light emitting diode) using an organic light emitting material as a light emitting material, holes and electrons are recombined in the EML 6 by the driving current between AN2 and CA7, and light is emitted in the process of excitons generated thereby migrating to the ground state.

[0098] In addition, the light emitting element 10 may be a light emitting element other than OLED and QLED (for example, an inorganic light emitting diode, etc.).

[0099] CA7 (second electrode) is made of a conductive material and injects electrons into EML6 through ETL5. Figure 1 As shown, CA7 is provided separately from AN2, for example, in contact with at least a portion of the upper surface of ETL5 and not in contact with EML6. CA7 is not located above EML6, and only needs to be in electrical contact with a portion of ETL5. On EML6, a sealing substrate 22 covering the light emitting element 10 is provided adjacent to EML6.

[0100] As mentioned above, ETL5 is composed of, for example, a low-resistance and opaque semiconductor material. According to this embodiment, by using a semiconductor material in the material of ETL5, a low-resistance ohmic contact can be obtained. Therefore, even if the contact area between CA7 and ETL5 is narrow, there is no problem. CA7 can be arranged between adjacent pixels P, and can also function as a shielding cover.

[0101] As the conductive material used in CA7, for example, metals such as Al, Ag, and Mg that are usually used for cathodes in the past can be listed; alloys of these metals; inorganic oxides such as ZnO (zinc oxide), ITO (indium tin oxide), and InGaZnOx (indium gallium zinc oxide); conductive compounds in which impurities are doped in these inorganic oxides, etc. These conductive materials can be used alone or in combination of two or more. In addition, the alloy can further contain Li (lithium).

[0102] In the above-described light-emitting element 10 , the thicknesses of layers other than IL4 and EML6 can be set in the same manner as in a conventional light-emitting element.

[0103] The thickness of EML6 is set to a thickness that can provide a site for recombination of electrons and holes and develop a light-emitting function. In addition, when QDs are used in EML6, for example, the thickness of EML6 is preferably several times the outermost particle diameter of QDs.

[0104] The particle size of QD can be set in the same manner as in the past. The particle size of the QD core is, for example, 1 to 30 nm, and the outermost particle size of QD including the shell is, for example, 1 to 50 nm. The number of QD stacking layers in the light emitting element 10 is, for example, 1 to 20 layers.

[0105] However, if the layer thickness of EML6 exceeds 100nm, it is difficult to fill the luminescent material into the recess CP. In addition, HTL3, IL4 and ETL5 have a conical cross-section. When the layer thickness of EML6 exceeds 100nm, the height of HTL3 and ETL5 also becomes higher accordingly. Therefore, if the layer thickness of EML6 exceeds 100nm, the cross-sectional area of ​​EML6 in the direction parallel to the surface of EML6 (that is, in the lateral direction in the cross-sectional view) also increases. As a result, the carrier injection density in the lateral direction in the cross-sectional view decreases, and the luminous efficiency decreases. Therefore, in order for EML6 to emit light well, the layer thickness of EML6 is preferably less than 100nm.

[0106] In addition, the cross-sectional area through which the current passes through the light-emitting element 10 is narrower than that of the conventional light-emitting element. However, the current density works advantageously when the cross-sectional area is narrow. The resistance of the HTL and ETL of the conventional light-emitting element is the same as that of the EML and cannot be ignored, but the resistance of the HTL and ETL of the present embodiment is very small compared to the EML and can be ignored.

[0107] In this embodiment, IL4 is provided only directly below ETL5, and EML6 is formed in concave portion CP including convex portion 3a, IL4, and ETL5 in a part of the side wall. Therefore, in this embodiment, the thickness of EML6 is set larger than that of IL4.

[0108] The thickness of IL4 is sufficient as long as the tunneling probability of carriers is sufficiently low. The thickness of IL4 is preferably set to be 5 nm or more. In addition, in order for EML6 to emit light well, the thickness of EML6 is preferably 5 nm or more. Therefore, the thickness of EML6 is preferably in the range of 5 nm or more and 100 nm or less, and more preferably in the range of more than 5 nm and 100 nm or less.

[0109] In addition, the height of the upper surface of EML6 is set to be lower than the height of the upper surface of the convex portion 3a and the upper surface of the ETL5. In addition, the height of the convex portion 3a is equal to the sum of the layer thickness of IL4 and the layer thickness of ETL5. Therefore, the height of the convex portion 3a of HTL3 and the sum of the layer thickness of IL4 and the layer thickness of ETL5 are set to be greater than the layer thickness of EML6.

[0110] In addition, for example, when QD is used in the light-emitting material of EML6, the distance between the adjacent convex portion 3a and ETL5 and IL4 is preferably more than twice the particle size of the QD. When the distance between the adjacent convex portion 3a and ETL5 and IL4 is narrower than the particle size of the QD, the QD cannot be filled in the concave portion CP. In order to fill the concave portion CP with QD without gaps, the above distance is preferably more than twice the width of the particle size of the QD.

[0111] In this embodiment, the outer dimensions of the EML6 of each recess CP when viewed from the upper surface side of the light emitting element 10 are equal to [the length of the protrusion 3a in the extension direction (= the length of the longitudinal line portion 5a in the extension direction)]X[the width between the protrusion 3a and the ETL5].

[0112] In addition, the length of the convex portion 3a in the extending direction and the width between the convex portion 3a and the ETL5 can be appropriately set according to the pixel size and are not particularly limited. As an example, the length of the convex portion 3a in the extending direction is 50 μm, and the width between the convex portion 3a and the ETL5 is set to 0.5 μm.

[0113] The line width of the convex portion 3a when observed from the upper surface side of the light-emitting element 10 is preferably 0.25μm as the lower limit by considering the limitation of the patterning selection ratio, and the upper limit is 50μm from the pixel pitch of 8K resolution in the diagonal 17-inch size. That is, the line width of the convex portion 3a when observed from the upper surface side of the light-emitting element 10 is preferably in the range of 0.25μm to 50μm. In addition, the line width of the ETL5 when observed from the upper surface side of the light-emitting element 10 is also preferably in the range of 0.25μm to 50μm for the same reason. In addition, here, "the line width of the convex portion 3a when observed from the upper surface side of the light-emitting element 10" means "the minimum width of the line width of the length of the convex portion 3a in the direction perpendicular to the extension direction of the convex portion 3a". In addition, "the line width of the ETL5 when observed from the upper surface side of the light-emitting element 10" means "the minimum width of the line width of the length of the ETL5 in the direction perpendicular to the extension direction of the ETL5".

[0114] In general photolithography processes, it is easy to process line spacings of about sub-micrometers. Therefore, the above-mentioned line widths and inter-electrode distances can also be easily processed. In addition, although the process cost increases, the line spacing can be further reduced in the current process, and the line spacing of about 0.1 μm can be processed.

[0115] The aspect ratio of EML 6 is in the range of 1 to 5. When the aspect ratio is in the range of 1 to 5 and the thickness of EML 6 is 100 nm or less, the ideal sub-pixel width (in other words, the width between the protrusion 3 a and the ETL 5 ) is 0.5 μm at maximum.

[0116] According to the present embodiment, there is no concept of sequential / inverse structure like in the conventional light emitting element, and connection with the TFT, carrier injection, and light extraction can be optimized independently.

[0117] <Method for Manufacturing Light Emitting Element 10 and Display Device 100>

[0118] Next, refer to Figures 4 to 7 , a method for manufacturing the light emitting element 10 and the display device 100 according to this embodiment is described. Figure 4 to Figure 7 1 is a cross-sectional view showing part of the manufacturing process of the light emitting element 10 in the display device 100 according to the present embodiment in order of process. Figure 4 to Figure 7 Shown with Figure 2 The cross section of the light emitting element 10 shown corresponds to the cross section of the display device 100 . Figure 5 express Figure 4 Manufacturing process following the manufacturing process shown. Figure 6 express Figure 5 Manufacturing process following the manufacturing process shown. Figure 7 express Figure 6 Manufacturing process following the manufacturing process shown.

[0119] First, as in Figure 4 As shown in S1, a substrate 1 as a support is prepared. Next, AN2 in contact with the drain of a TFT (not shown) in the substrate 1 is formed on the entire surface of the display region of the substrate 1 (step S1, first electrode forming step).

[0120] The substrate 1 can be made in advance by a known TFT process, or a commercially available array substrate can be used. The substrate 1 can be made, for example, by the following method. First, a TFT layer including TFTs and a plurality of wirings is formed on an insulating substrate by a known method. Next, a planarization layer composed of a photosensitive resin is formed on the TFT layer by a known method. Thereafter, a contact hole for connecting AN2 to the drain electrode of the TFT is formed on the planarization layer. Thus, a substrate 1 provided with a plurality of TFTs is formed.

[0121] In forming AN2, various conventionally known methods can be used as anode forming methods such as vapor deposition, sputtering, and a method of heating after coating nanoparticles. AN2 is connected to the drain electrode of the TFT via a contact hole formed in the planarization layer.

[0122] Next, as in Figure 4 As indicated by S2 , a hole transporting material layer 13 made of a hole transporting material, which will become HTL3 , is formed on the entire surface of AN2 (step S2 ).

[0123] The hole transport material layer 13 can be formed by sputtering, coating and sintering, or nanoparticle coating, etc. The hole transport material layer 13 is formed to have a thickness greater than that of the EML 6 .

[0124] Then, as in Figure 4 As shown in S3 , a mask 111 for processing the surface of the hole transporting material layer 13 into a concavo-convex shape is formed on the hole transporting material layer 13 as an etching mask (step S3 ).

[0125] As the mask 111 , a resist pattern may be formed by a common photolithography method, or a metal mask may be used to cover the formation region of the convex portion 3 a in the hole transport material layer 13 instead of the resist pattern.

[0126] After the mask 111 is formed, as in Figure 5 As shown in step S4, the surface of the hole transport material layer 13 is etched by wet etching or dry etching to form a concavo-convex surface. Then, the mask 111 is removed. Thus, the HTL 3 having a plurality of convex portions 3a on the surface is formed (step S4).

[0127] Specifically, the region of the surface of the hole transport material layer 13 not covered by the mask 111 in plan view is etched. Thus, a concave portion having a residual film thickness T1 is formed in the region not covered by the mask 111. Also, a convex portion 3a is formed in the region covered by the mask 111.

[0128] In addition, here, the remaining film thickness T1 represents the layer thickness of the portion other than the convex portion 3a in HTL3. The remaining film thickness T1 is preferably as thin as about 5nm or more and 20nm or less. Between EML6 and AN2, which is the lower light reflection electrode, it is preferred that the light absorption is small. The lower limit of the residual film thickness T1 that can leave HTL3 in the form of a continuous film is 5nm, and the upper limit of the residual film thickness T1 that does not affect the light absorption is 20nm. In addition, the layer thickness of HTL3 is represented by the sum of the remaining film thickness T1 and the height of the convex portion 3a.

[0129] According to the present embodiment, the HTL 3 is formed to have the convex portion 3 a protruding upward on the surface through the first carrier transport layer forming step including the above-described steps S2 to S4 .

[0130] Next, as in Figure 5 As shown in S5 , the insulating film 14 to be the IL4 is formed entirely on the HTL 3 so as to cover the protrusion 3 a (step S5 ).

[0131] When the insulating film 14 is made of an inorganic insulating material, sputtering, CVD (chemical vapor deposition) or the like can be used for forming the insulating film 14. Alternatively, when the insulating film 14 is made of an organic insulating material such as a resin, a coating method or the like can be used.

[0132] Then, as in Figure 5 As shown in S6 , the electron transport material layer 15 to be the ETL 5 is formed between the protrusions 3 a covered by the insulating film 14 so that the upper surface of the electron transport material layer 15 is at the same height as the upper surface of the protrusion 3 a (step S6 ).

[0133] The electron transport material layer 15 can be formed by the same method as the hole transport material layer 13 , such as sputtering, coating and sintering, or nanoparticle coating.

[0134] Then, as in Figure 6 As shown in S7, a pattern forming process is formed on the electron transport material layer 15 as an etching mask. Figure 1 as well as Figure 2 The mask 112 of the ETL 5 having the shape shown is formed (step S7).

[0135] As the mask 112 , a resist pattern may be formed by a common photolithography method, or a metal mask may be used to cover the pattern formation region of the ETL 5 instead of the resist pattern.

[0136] Then, as in Figure 6As shown in step S8, the portion of the electron transport material layer 15 not covered by the mask 112 is removed by wet etching or dry etching. Thereafter, the mask 112 is removed. Thus, an island-shaped ETL 5 having a desired pattern is formed (step S8).

[0137] According to this embodiment, the second carrier transport layer forming process including steps S6 to S8 is performed to form an island-shaped ETL5 separated from HTL3. According to this embodiment, steps S6 to S8 are performed after step S5 to finally form ETL5 on HTL3 via IL4.

[0138] Then, as in Figure 6 As shown in S9 , a mask 113 for patterning the insulating film 14 so as to conform to the shape of the ETL 5 is formed on the ETL 5 as an etching mask (step S9 ).

[0139] As the mask 113 , a resist pattern may be formed by a common photolithography method, or the upper surface of the ETL 5 may be covered with a metal mask instead of the resist pattern.

[0140] Then, as in Figure 7 As shown in S10, the portion of the insulating film 14 not covered by the mask 113 and the ETL5 is removed by etching or ashing. Then, the mask 113 is removed. Thus, the pattern is formed into an island-shaped IL4 having a shape similar to that of the ETL5. Figure 1 As shown in FIG. 1 , a bank BK having a height higher than the upper surface of the convex portion 3a and the upper surface of the ETL5 is formed. Thus, a concave portion CP surrounded by the HTL3, IL4, ETL5 and the bank BK is formed in each pixel P. Figure 1 As shown, CA7 is formed on ETL5 (step S10).

[0141] According to the present embodiment, after step S5 , etching or ashing of the insulating film 14 and removal of the mask 113 are performed in steps S9 and S10 , thereby forming the IL4 as described above (insulating layer forming step).

[0142] In addition, in this embodiment, as described above, the case where CA7 is formed (second electrode forming process) after bank BK is formed (bank forming process) is described as an example. However, the order of forming CA7 (second electrode forming process) and forming bank BK (bank forming process) may be reversed.

[0143] The bank BK can be formed by, for example, coating of a bank material and photolithography.

[0144] In addition, CA7 can be formed by the same method as HTL3, IL4 and ETL5. Specifically, after forming the conductive layer of CA7, an etching mask is formed on the conductive layer, and the conductive layer is etched by wet etching or dry etching, and then the mask is removed. In addition, CA7 can also be formed by printing, evaporation, CVD, etc. In the formation of the conductive layer, various methods known in the past can be used as the cathode film forming method such as evaporation or sputtering. In this way, the light-emitting element 10 involved in this embodiment is manufactured.

[0145] In addition, Figure 6 In S8 and S9 of FIG. 1 , the case where the mask 113 is formed after the mask 112 is removed is illustrated as an example. However, depending on the type of the mask 112 and the etching method, the mask 112 may be used directly for patterning the IL4 without being removed.

[0146] Next, as in Figure 7 As shown in S11 , the EML 6 is formed in the concave portion CP which is a space portion between the HTL 3 and the ETL 5 in a plan view (step S11 , light emitting layer forming step).

[0147] The EML6 can be formed by filling the above-mentioned concave portion CP with a luminescent material by, for example, inkjet coating. In the case where the EML6 is a QD layer including QDs, the EML6 can be formed by inkjet coating a colloidal solution in which QDs are dispersed on the above-mentioned concave portion CP, etc. At this time, the EML6 adjusts the formation conditions such as the layer thickness of the EML6 so that the height of the upper surface of the EML6 is lower than the height of the upper surface of the convex portion 3a and the upper surface of the ETL5.

[0148] According to the present embodiment, the EML 6 can be formed last as described above, and the light emitting element 10 can be manufactured without causing process damage to the EML 6 .

[0149] After step S12 , the light emitting element 10 is sealed with the sealing resin 21 and the sealing substrate 22 , thereby manufacturing the display device 100 .

[0150] <Effect>

[0151] As described above, the light emitting element 10 according to the present embodiment includes AN2, HTL3, CA7, ETL5, and EML6. At least a portion of EML6 overlaps a portion of HTL3, and a portion of EML6 overlaps a portion of ETL5. HTL3 and ETL5 are disposed opposite to each other with EML6 interposed therebetween in a plan view.

[0152] The light-emitting element 10 performs carrier injection and light extraction from different directions. As described above, in the light-emitting element 10, when viewed from above, HTL3 and ETL5 are opposite to each other with EML6 sandwiched therebetween. Therefore, carriers can be injected from the lateral direction in the in-plane direction of EML6, i.e., in the cross-sectional view, and on the other hand, light can be extracted in the longitudinal direction (specifically, the upward direction) in the direction intersecting the lateral direction, i.e., in the cross-sectional view. Therefore, carrier injection and light extraction can be performed independently and the most appropriate design can be performed respectively. In addition, the most appropriate manufacturing processes can be adopted for the manufacture of HTL3 and ETL5, and the manufacture of AN2 and CA7, respectively.

[0153] In addition, as described above, EML6 is provided on a portion of HTL3 and a portion of ETL5. Therefore, EML6 is formed by a process later than HTL3 and ETL5. EML6 is located at a position higher than HTL3 and ETL5, and there is no electrode and carrier transport layer on the upper surface of EML6 which becomes the light extraction surface of EML6 (that is, on the light extraction path). Therefore, the light emitting element 10 does not need to use a transparent material in one of a pair of electrodes and one of a pair of carrier transport layers as in the existing light emitting element, and the freedom of selection of materials for the electrode and the carrier transport layer is higher than before.

[0154] For AN2, CA7, HTL3, and ETL5, it is possible to use a good conductive material without optical restrictions for the purpose of improving light extraction efficiency and improving electrical characteristics. Therefore, according to this embodiment, it is possible to achieve both improvement in light extraction efficiency and improvement in electrical characteristics.

[0155] Furthermore, the light emitting element 10 is not affected by light absorption or refractive index difference of electrodes and carrier transport layers provided on the light extraction path of the EML 6 as in conventional light emitting elements.

[0156] Therefore, according to this embodiment, it is possible to provide a light emitting element 10 , a display device 100 , and a method for manufacturing the light emitting element 10 , which have a higher degree of freedom in selecting materials for electrodes and carrier transport layers than before and can improve light extraction efficiency.

[0157] As described above, the light emitting element 10 does not have other layers such as electrodes and carrier transport layers on the light extraction path of the EML 6. Therefore, according to this embodiment, process damage of the EML 6 can be reduced compared with conventional light emitting elements.

[0158] in addition, Figure 8 1 is a plan view showing the relationship between a pixel P and a light-emitting region of the display device 100 according to the present embodiment. Fig. 9This is a cross-sectional view schematically showing the structure of a main part of the display device described in Patent Document 1. Fig.10 Yes means Fig. 9 A top view showing the relationship between a pixel P and a light emitting area of ​​a display device shown.

[0159] like Figure 2 and Figure 8 As shown, the display device 100 involved in this embodiment requires only small banks BK at the four corners of the pixel P. The line width of the convex portion 3a and the line width of the ETL5 vary according to the line width of the photolithography and the selectivity of the etching, and can be controlled to a certain extent. The line width of the convex portion 3a and the line width of the ETL5 obtained after etching the HTL3 and the ETL5 is twice the selectivity of the exposure line width.

[0160] Assuming the above selection ratio is 0.5, if Figure 8 The pixel effective area ratio of the display device 100 shown is EA1, and EA1=(1×50)×2 / (50.25×2.5)≈0.80. The pixel effective area is represented by the area of ​​the light emitting region relative to the area of ​​the pixel P.

[0161] On the other hand, Fig. 9 and Fig.10 As shown in FIG. 1 , if the effective area ratio of pixels of the conventional display device (Patent Document 1) is EA2, then EA2 = 1 × 1 / (1.7 × 1.7) ≈ 0.35.

[0162] Therefore, according to the present embodiment, compared with a conventional display device, the effective area ratio of pixels can be improved, and a higher aperture ratio than conventional ones can be achieved.

[0163] The pixel effective area ratio is determined by the long side size of the pixel P ( Figure 8 The vertical dimension of the pixel P shown is determined by: Fig.11 represents the relative length of the long side of the pixel P to the short side of the pixel P in the display device 100 according to the present embodiment ( Figure 8 The graph of the relationship between the ratio of the horizontal dimension of the pixel P shown in FIG. Fig.11 , the effective pixel area ratio is shown when the ratio of the long side dimension of the pixel P to the short side dimension of the pixel P is changed to 0.5 to 50. Fig.11 As shown, by setting the ratio of the long side dimension of the pixel P to the short side dimension of the pixel P to 10 or more, a pixel effective area ratio close to 0.9 (that is, 90%) can be obtained.

[0164] In addition, the pixel effective area ratio equivalent to that of the existing display device is also satisfied in a state close to a square in which the ratio of the long side dimension of the pixel P to the short side dimension of the pixel P is less than 1. In addition, the existing display device has a carrier transport layer and an electrode on the light extraction surface side above the EML, and the transmittance of the carrier transport layer and the electrode on the light extraction surface side needs to be considered.

[0165] However, according to the present embodiment, as described above, a good conductive material that is not subject to optical constraints can be used for any carrier transport layer and electrode, and both the improvement of light extraction efficiency and the improvement of electrical characteristics can be taken into account. In addition, as the carrier transport layer and electrode, it is assumed that the transmittance in the case of Al, Mg, ZnO, ITO, InGaZnOx, etc. is 80% to 90%. However, the light-emitting element 10 of the present embodiment does not have other layers above the EML 6, and there is no need to consider the absorption of light by the carrier transport layer and the electrode above the EML 6 as in the existing display device.

[0166] <Variation 1>

[0167] Fig.12 It is a perspective view showing a schematic configuration of the main parts of the display device 100 according to the present modification example when viewed from above.

[0168] like Fig.12 As shown, the ETL5 involved in this modification has a fishbone shape when viewed from above. More specifically, the ETL5 has a longitudinal line portion 5a, a transverse line portion 5b, and a plurality of branch line portions 5c located between the transverse line portions 5b and protruding in a comb-like manner into each recessed portion CP in a manner intersecting the longitudinal line portion 5a when viewed from above. Therefore, the IL4 involved in this modification also has a fishbone shape, which has a longitudinal line portion 4a, a transverse line portion 4b, and a plurality of branch line portions 4c located between the transverse line portions 4b and protruding in a comb-like manner into each recessed portion CP in a manner intersecting the longitudinal line portion 4a when viewed from above.

[0169] In addition, the convex portion 3a involved in this modified example has a fishbone shape, which has a longitudinal line portion 3a1 as a main line portion extending longitudinally parallel to the longitudinal line portion 5a when viewed from above, and a plurality of branch line portions 3a2 protruding in a comb-tooth shape into each recess CP in a manner intersecting the longitudinal line portion 3a1.

[0170] In this modification, the branch line portion 5c and the branch line portion 3a2 are extended in parallel with the horizontal line portion 5b. In addition, the ETL5 and the convex portion 3a are formed into a comb shape relative to each concave portion CP when viewed from above, and the branch line portion 5c and the branch line portion 3a2 as the respective comb teeth are alternately arranged in a mutually meshing manner. In this way, by providing the concave and convex in the top view on the HTL3 and ETL5 as the side walls of the concave portion CP, the carrier injection area can be expanded and the carrier injection property based on the HTL3 and ETL5 can be improved. In addition, the aspect ratio of the EML6 can be substantially reduced.

[0171] However, the mutually adjacent branch line portions 5c and branch line portions 3a2 may be arranged relative to each other in the extending direction of each branch line portion 5c, 3a2, and do not necessarily need to be arranged alternately. In addition, the branch line portions 5c and branch line portions 3a2 do not necessarily need to be parallel to the horizontal line portion 5b.

[0172] <Variation 2>

[0173] Fig.13 It is a perspective view showing a schematic configuration of the main parts of the display device 100 according to the present modification example when viewed from above.

[0174] For example Fig.13 As shown, it is preferred that the convex portion 3a, IL4 and ETL5 have curved corners when viewed from above. In other words, it is preferred that the convex portion 3a, IL4 and ETL5 have a shape that eliminates the corners where straight lines intersect each other when viewed from above. Thereby, local electric field concentration at the corners of the convex portion 3a, IL4 and ETL5 can be avoided.

[0175] In addition, Fig.13 As an example, the Fig.12 The convex portion 3a, IL4 and ETL5 shown in the figure have curved corners in a plan view, but the present embodiment is not limited to this. Figure 1 The ETL5 and IL4 shown may also have curved corners when viewed from above. Figure 1 as well as Figure 2 In the example shown, when the lower electrode is CA7, HTL3 may have a curved corner in a plan view.

[0176] <Variation 3>

[0177] Fig.14 It means along Figure 1 II wire cut shown Figure 1 The display device 100 shown is another cross-sectional view schematically showing the structure of the main parts of the display device 100 .

[0178] like Fig.14As shown, it is preferred that the convex portion 3a, IL4 and ETL5 have a curved cross-sectional shape. In other words, when observed in cross section, it is preferred that the convex portion 3a, IL4 and ETL5 have curved wavy corners without any corners where straight lines intersect each other. Thus, local electric field concentration at the corners of the convex portion 3a, IL4 and ETL5 can be avoided.

[0179] It should be noted that the method of forming the corners of the convex parts 3a, IL4 and ETL5 into a wave shape is not particularly limited. For example, the convex parts 3a, IL4 and ETL5 having a convex structure with a gentle inclination angle at the end surface can be formed by light interference caused by half exposure and the resolution of the exposure machine.

[0180] <Other Modifications>

[0181] As mentioned above, in Figure 3 In the embodiment, as the sealing substrate 22, for example, a glass substrate (sealing glass) is used. Furthermore, by bonding the substrate 1 and the sealing substrate 22 via the sealing resin 21, glass sealing of the light-emitting element 10 (so-called can sealing without an organic sealing film and an inorganic sealing film) is performed. However, the sealing method of the light-emitting element 10 is not limited to the above method. For example, instead of the sealing resin 21 and the sealing substrate 22, a sealing substrate (sealing glass) composed of frame-shaped glass formed by forming sintered glass (powdered glass) into a frame shape may be used to perform can sealing of the light-emitting element 10. In addition, on the upper surface of the light-emitting element 10, as a sealing layer, for example, an organic sealing layer may be formed by an inkjet method, or an inorganic sealing film composed of a nitride film may be formed by a CVD method.

[0182] However, if a film is formed on the EML 6 , the EML 6 may be damaged, which may adversely affect the light-emitting characteristics.

[0183] Therefore, among the above-mentioned sealing methods, can sealing of the light emitting element 10 using the above-mentioned sealing substrate 22 or frame-shaped glass is particularly preferable. This can protect the light emitting element 10 without causing process damage to the EML 6.

[0184] In addition, Figure 2 In the embodiment, the case where AN2 is the lower electrode and CA7 is the upper electrode is described as an example. However, the present disclosure is not limited thereto, and CA7 may be the lower electrode and AN2 may be the upper electrode. In this case, CA7 may be used as the reflective electrode.

[0185] By arranging AN2, HTL3, IL4, ETL5, and CA7 so that the side of HTL3 and ETL5 where carrier injection is difficult is on the lower side, the electric field distribution applied to EML6 can be expanded, and the injection of carriers can be further improved.

[0186] In this embodiment, the display device 100 is described as an example of a light-emitting device (electronic device) including the light-emitting element 10. However, the light-emitting element 10 can also be applied to light-emitting devices other than the display device 100, such as lighting devices.

[0187] [Implementation Method 2]

[0188] In this embodiment, the differences from Embodiment 1 are described. In addition, for convenience of description, components having the same functions as those described in Embodiment 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

[0189] Fig.15 1 is another cross-sectional view showing a schematic structure of a main part of the display device 100 according to the present embodiment. Figure 1 The same. Therefore, Fig.15 Equivalent to Figure 1 II wire cut shown Figure 1 The display device 100 shown is another cross-sectional view schematically showing the structure of a main part of the display device 100 .

[0190] The light emitting element 10 and the display device 100 according to this embodiment have the same structure as the light emitting element 10 and the display device 100 according to Embodiment 1 except for the following points. Fig.15 As shown, IL4 of the light emitting element 10 and the display device 100 according to this embodiment is formed in an island shape on HTL3 so as to cover the entire bottom surface of the recess CP. Therefore, the bottom surface of the recess CP of the light emitting element 10 and the display device 100 according to this embodiment is formed by IL4.

[0191] As in Embodiment 1, in this embodiment, EML6 is formed so that the height of the upper surface of EML6 is lower than the height of the upper surface of HTL3 and the upper surface of ETL5. However, in this embodiment, the depth of the recessed portion CP surrounded by HTL3, IL4, ETL5, and bank BK is smaller than that of the light emitting element 10 and the display device 100 involved in Embodiment 1, and the thickness of IL4 is smaller. In this embodiment, the depth of the recessed portion CP is equal to the thickness of ETL5. Therefore, in this embodiment, ETL5 and EML6 are formed in such a way that the thickness of ETL5 is greater than the thickness of ETL6.

[0192] Next, a method for manufacturing the light emitting element 10 and the display device 100 according to this embodiment will be described. Fig.161 is a cross-sectional view showing part of the manufacturing process of the light emitting element 10 in the display device 100 according to the present embodiment in order of process. Fig.16 Shown with Fig.15 The cross section of the light emitting element 10 shown corresponds to the cross section of the display device 100. Fig.16 express Figure 6 The manufacturing process after the manufacturing process shown in S8.

[0193] In this embodiment, similarly to the first embodiment, after performing steps S1 to S8, as in Fig.16 As indicated by S9 in the figure, as step S9, a mask 113 is formed on the ETL 5 and between the protrusion 3a covered by the insulating film 14 and the ETL 5.

[0194] Then, as in Fig.16 As shown in step S10, as step S10, the portion of the insulating film 14 not covered by the mask 113 and the ETL5 is removed by etching or ashing. Then, the mask 113 is removed. Thus, the IL4 is patterned into an island shape so as to cover the entire bottom surface of the concave portion CP. Next, as in the first embodiment, Figure 1 As shown in FIG. 1 , a bank BK having a height higher than the upper surface of the convex portion 3a and the upper surface of the ETL5 is formed. Thus, a concave portion CP surrounded by the HTL3, IL4, ETL5, and the bank BK is formed in each pixel P. Figure 1 As shown, C77 is formed on ETL5 in the same manner as in the first embodiment (step S10).

[0195] Then, as in Fig.16 As shown in S11, in the concave portion CP, EML6 is formed in the same manner as in Embodiment 1 (step S11, light-emitting layer forming process). At this time, in this embodiment, the formation conditions of EML6 such as the layer thickness of EML6 are adjusted so that the height of the upper surface of EML6 is lower than the height of the upper surface of the convex portion 3a and the upper surface of ETL5.

[0196] Thereafter, the light emitting element 10 is sealed in the same manner as in Embodiment 1, thereby manufacturing the display device 100 .

[0197] In the light emitting element 10 according to the first embodiment, since the IL4 as the insulating layer exists only directly below the ETL5, the electric field is concentrated around the IL4 where the ETL5 and the HTL3 are close, and localized light emission may occur.

[0198] In contrast, in this embodiment, since the bottom surface of the recess CP is formed by IL4, the electric field is not concentrated only on a portion around IL4, and the current flows in a direction parallel to the surface of the substrate 1. Therefore, according to this embodiment, the light emitting element 10 can emit light uniformly in the planar direction.

[0199] <Implementation method 3>

[0200] This embodiment will describe the differences from Embodiments 1 and 2. For convenience of description, components having the same functions as those described in Embodiments 1 and 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0201] Fig.17 This is a perspective view showing a schematic configuration of a main part of the display device 100 according to the present embodiment when viewed from above. Fig.18 It means use Fig.17 The II-II line shown is cut Fig.17 The display device 100 shown in FIG. 1 is a cross-sectional view schematically showing the main structure of the display device 100. Fig.17 In FIG. 1 , the upper surface of the display device 100 is shown through the sealing substrate 22 .

[0202] The light emitting element 10 and the display device 100 according to this embodiment have the same structures as those of the light emitting element 10 and the display device 100 according to Embodiment 1 except for the following points. Fig.17 as well as Fig.18 As shown, the light emitting element 10 and the display device 100 according to the present embodiment are formed so that the lower surface of CA7 has the same shape as the upper surface of ETL5 and overlaps with ETL5. Therefore, CA7 has a shape similar to that of ETL5 and IL4.

[0203] In addition, Fig.17 In the example, CA7, ETL5 and IL4 are formed in an I-shape when viewed from above. However, the planar shapes of CA7, ETL5 and IL4 are not limited to the above shapes. Fig.12 or Fig.13 The planar shapes of ETL5 and IL4 shown are the same planar shapes.

[0204] Next, a method for manufacturing the light emitting element 10 and the display device 100 according to this embodiment will be described. Fig.19 as well as Fig. 20 1 is a cross-sectional view showing part of the manufacturing process of the light emitting element 10 in the display device 100 according to the present embodiment in order of process. Fig.19as well as Fig. 20 Shown with Fig.18 The cross section of the light emitting element 10 shown corresponds to the cross section of the display device 100 . Fig.19 express Figure 5 The manufacturing process after the manufacturing process shown in S6. Fig. 20 express Fig.19 The manufacturing process after the manufacturing process shown.

[0205] In this embodiment, after performing steps S1 to S6 in the same manner as in embodiment 1, Fig.19 As shown in step S21 , a conductive layer 17 made of a conductive material, which will become CA7, is formed in the entire surface on the electron transport material layer 15 and the insulating film 14 (step S21 ).

[0206] In forming the conductive layer 17 , various conventionally known methods can be used as a cathode film forming method such as a vapor deposition method or a sputtering method.

[0207] Next, if Fig.19 As shown in S22, on the conductive layer 17, a pattern forming Fig.17 and Fig.18 The mask 114 of CA7 and ETL5 of the shape shown is formed (step S22).

[0208] As the mask 114, a resist pattern may be formed by a common photolithography method, or a metal mask may be used to cover the pattern formation region of CA7 and ETL5 instead of the resist pattern.

[0209] Then, as in Fig.19 As shown in step S23, the conductive layer 17 and the electron transport material layer 15 are removed by wet etching or dry etching, except for the portions not covered by the mask 114. Then, the mask 114 is removed. Thus, the island-shaped CA7 and ETL5 having a desired pattern are formed (step S23).

[0210] Then, if Fig. 20 As shown in S9 to S11 of the embodiment, except that CA7 having a shape similar to that of ETL5 is formed on ETL5, the same steps S9 to S11 as those of the embodiment 1 are performed. Then, the light emitting element 10 is sealed by using the sealing resin 21 and the sealing substrate 22, thereby manufacturing the Fig.17 and Fig.18 The display device 100 is shown.

[0211] That is, in this embodiment, instead of step S7, step S8, and step S12, steps S21 to S23 are performed to manufacture the display device 100. Fig. 20As shown in S11, EML6 adjusts the formation conditions such as the layer thickness of EML6 so that the height of the upper surface of EML6 is lower than the height of the upper surface of the convex portion 3a and the upper surface of ETL5. Therefore, in this embodiment, although CA7 is in contact with the entire upper surface of ETL5, in this embodiment, CA7 is formed in a manner that does not contact EML6. Therefore, even in this embodiment, EML6 will not be damaged by the process due to CA7 being stacked on EML6. In addition, light absorption by CA7 is not accepted in the light extraction direction, which can improve the light extraction efficiency.

[0212] Therefore, according to this embodiment, in addition to the effects of Embodiment 1, CA7 and ETL5 can be patterned together as described above, and CA7 and ETL5 can be easily formed. In addition, when AN2 is an upper electrode, AN2 and HTL3 can be patterned together, and AN2 and HTL3 can be easily formed.

[0213] <Implementation method 4>

[0214] In this embodiment, the differences from Embodiments 1 to 3 are described. In addition, for convenience of description, components having the same functions as those described in Embodiments 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

[0215] Fig.21 It is a plan view showing a schematic structure of the main parts when the light emitting element 30 according to the present embodiment is viewed from above. Fig. 22 It means along Fig.21 The III-III line shown will Fig.21 The light emitting element 30 shown is a cross-sectional view schematically showing the structure of the main part of the light emitting element 30 when the light emitting element 30 is cut.

[0216] The light emitting element 30 according to this embodiment has the same structure as the light emitting element 10 according to Embodiment 1 except for the following points. Although not shown in the figure, the display device 100 according to this embodiment includes the light emitting element 30 shown below instead of the light emitting element 10. Fig.21 and Fig. 22 As shown, in the light emitting element 30 according to the present embodiment, the HTL 3 has a concentric shape centered on the ETL 5 in a plan view. More specifically, the light emitting element 30 surrounds the outer periphery of the ETL 5 in a frame shape so that the ETL 5 is located at the center of the pixel P and the convex portion 3 a surrounds the ETL 5 .

[0217] HTL3 has a similar shape to ETL5 when viewed from above. Fig.21 and Fig. 22In the example shown, the case where the ETL 5 is circular in a plan view and the HTL 3 is formed in a circular shape having the convex portion 3 a in an annular shape (in other words, a circular frame shape) is exemplified.

[0218] In this embodiment, EML6 is formed in the concave portion CP surrounded by HTL3, IL4 and ETL5. In other words, EML6 is formed in the concave portion CP including the convex portion 3a, IL4 and ETL5 on a part of the side wall. In addition, since the convex portion 3a of the light-emitting element 30 surrounds the outer periphery of the ETL5 in a frame shape as described above, the bank BK is not required in the formation of the concave portion CP and the separation of each pixel P.

[0219] If used Fig. 22 As shown in the box F3 surrounded by two dotted lines, a part of EML6 is formed overlappingly on a part of HTL3. Fig. 22 As shown in the frame F4 surrounded by two-dot chain lines, a part of the EML 6 is formed overlapping with a part of the ETL 5 .

[0220] In addition, in the light emitting element 30, CA7 is formed in an island shape on each pixel P, AN2 can be formed in common on each pixel P, AN2 can be formed in an island shape on each pixel P, and CA7 can be formed in common on each pixel P. CA7 can be arranged between adjacent pixels P as long as it is in electrical contact with a part of ETL5.

[0221] In this embodiment, for example, Figure 4 S3 and Figure 5 In S4 shown in FIG. Fig.21 As shown in FIG. 1 , HTL 3 is formed into a circular shape having an annular convex portion 3a. Figure 6 In S7 and S8 shown in FIG. 1 , the ETL 5 is formed into a circular shape having a circular protrusion 3 a at the center of the pixel P in a plan view. Fig.16 In S9 and S10 shown in FIG. 1 , no bank BK is formed. Fig.16 The IL4 is patterned in the same manner as in S9 and S10 shown in the figure. Except for these points, the same steps as those shown in the second embodiment can be performed to manufacture the Fig.21 and Fig. 22 The light emitting element 30 and the display device 100 including the light emitting element 30 are shown.

[0222] As described above, the light emitting element 30 involved in this embodiment is the same as the light emitting element 10, and includes AN2, HTL3, CA7, ETL5, and EML6. In addition, at least a portion of EML6 overlaps a portion of HTL3, and a portion of EML6 overlaps a portion of ETL5. HTL3 and ETL5 are arranged opposite to each other with EML6 sandwiched therebetween in a plan view. Therefore, according to this embodiment, the same effect as that of Embodiment 1 can be obtained.

[0223] In addition, according to this embodiment, Fig.21 and Fig. 22 In the process, since the lateral electric field (that is, the electric field in the in-plane direction of the EML 6) is evenly distributed around, light can be emitted uniformly in the planar direction.

[0224] <Modification>

[0225] Figure 23 to Figure 26 Each of them is a plan view schematically showing the structure of the main part when the light emitting element 30 according to the present modification example is viewed from above.

[0226] Figure 23 to Figure 25 In the illustrated light emitting elements 30, when viewed from above, HTL3 has a concentric shape with ETL5 as the center, and the convex portion 3a surrounds the periphery of ETL5 in a frame shape. In addition, in any example, HTL3 has a shape similar to ETL5 in a top view. In addition, in a top view, the outer shape of the pixel P is the same as that of the HTL3.

[0227] like Fig.23 As shown in FIG. 1 , HTL3 and ETL5 may also be formed into a longitudinal elliptical shape in which the longitudinal axis is longer than the lateral axis when viewed from above. Fig.24 As shown in FIG. 1 , HTL3 and ETL5 may also be formed into a transverse elliptical shape in which the horizontal axis is longer than the vertical axis when viewed from above. Fig.25 As shown, HTL3 and ETL5 may also be formed into a regular polygon (a regular n-sided shape, where n is an integer greater than or equal to 3) in a plan view. Fig.25 The example in which HTL3 and ETL5 are formed as regular hexagons with n = 6 is shown. However, regular pentagons with n = 5 and polygons with n being an integer multiple of 5 cannot form a plurality of pixels P in an array without gaps between the pixels P. Therefore, n≠(integer multiple of 5) is preferred.

[0228] in addition, Figure 23 to Figure 25 The convex portion 3a and the ETL5 shown may each have a comb-shaped concave-convex shape when viewed from above. As an example, Fig.26 For example, Fig.23 The convex portion 3 a and the ETL 5 shown in the figure are provided with comb-shaped concavities and convexities in a plan view. Fig.26The ETL 5 shown has a convex portion 5d protruding in a comb-tooth shape in the concave portion CP on the surface facing the convex portion 3a in a plan view. Fig.26 The convex portion 3a shown has a convex portion 3a3 protruding in a comb-teeth shape into the concave portion CP on the surface facing the ETL 5 in a plan view.

[0229] Thus, the HTL3 and ETL5 (in other words, the convex portion 3a and ETL5) facing each other in a plan view have a comb-shaped structure in a plan view, so that the carrier injection property of the HTL3 and ETL5 can be further improved. In addition, the aspect ratio of the EML6 can be substantially reduced.

[0230] In addition, Figure 21 to Figure 26 , an example is shown in which the HTL 3 has a concentric shape with the ETL 5 as the center when viewed from above. However, it goes without saying that the ETL 5 may also have a concentric shape with the HTL 3 as the center.

[0231] <Implementation method 5>

[0232] In this embodiment, the differences from Embodiments 1 to 4 are described. In addition, for convenience of description, components having the same functions as those described in Embodiments 1 to 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

[0233] <Schematic Structure of Display Device 100 and Light Emitting Element 40 >

[0234] Fig. 27 It is a cross-sectional view schematically showing the structure of a main part of a display device 100 according to the present embodiment.

[0235] like Fig. 27 As shown in FIG. 1 , the display device 100 according to this embodiment has the same structure as the display device 100 according to Embodiment 1, except that the light emitting element 40 is provided instead of the light emitting element 10. Therefore, in this embodiment, a light emitting element 40R that emits red light is provided in the red pixel RP. A light emitting element 40G that emits green light is provided in the green pixel GP. A light emitting element 40B that emits blue light is provided in the blue pixel BP. In this embodiment, when it is not necessary to distinguish these light emitting elements 40R, 40G, and 40B, these light emitting elements 40R, 40G, and 40B are collectively referred to as "light emitting element 40".

[0236] In addition, for convenience of description, the light reflective electrode is denoted as “RE” and the resin layer is denoted as “RL” below.

[0237] like Fig. 27As shown, the light emitting element 40 includes RE41, RL42, AN43, CA44, IL45, HTL46, ETL47, EML48, and a bank BK (not shown).

[0238] Hereinafter, an example is given in which AN43 is a pixel electrode (first electrode) formed in an island shape in each pixel P, and CA44 is a common electrode (second electrode) shared by each pixel P. However, the present embodiment is not limited thereto, and CA44 may be a pixel electrode (first electrode) and AN43 may be a common electrode.

[0239] The display device 100 according to this embodiment is similar to the display device 100 according to Embodiment 1, and is a top emission type display device that emits light generated by the EML 6 from the side opposite to the substrate 1 .

[0240] RE41 is formed in a whole surface on the substrate 1 so as to cover the surface of the substrate 1. Examples of the conductive material used for RE41 include light-reflective metals such as Al, Ag, and Mg, and alloys of these metals.

[0241] According to the present embodiment, by providing the RE 41 , light can be easily extracted from the upper surface direction of the EML 48 .

[0242] RL42 is a common layer shared by each pixel P, and is formed in a solid state on RE41 so as to cover the surface of RE41. RL42 has a plurality of convex portions 42a protruding upward. The convex portions 42a are provided to protrude in a direction perpendicular to the surface of the substrate 1, for example.

[0243] Although not shown in the figure, in the present embodiment, a plurality of pixels P are arranged in a matrix along the horizontal and vertical directions in the display area of ​​the display device 100. Each pixel P is formed in a rectangular shape, for example. The convex portions 42a are provided on the vertical direction boundary between, for example, horizontally adjacent pixels P, separated from each other along the boundary (in other words, the vertical direction) in a plan view.

[0244] As the material of RL42, for example, organic insulating materials such as polyimide and acrylic resin can be cited. The height of the convex portion 42a is, for example, in the range of several hundred nm to several μm. The height of the convex portion 42a can be formed in such a way that the sum of the thickness of IL45 and the thickness of EML48 is lower than the sum of the height of the convex portion 42a, the thickness of AN43, and the thickness of HTL46 while the thickness of EML6 is set within the above range. As a result, the height of the upper surface of EML48 is lower than the height of the upper surface of HTL46 and the height of the upper surface of ETL47.

[0245] The thickness of RL42 between the protrusions 42a can be any thickness that can ensure the insulation between RE41 and AN43 and CA44 and can be processed. The thickness of RL42 between the protrusions 42a is preferably in the range of 20nm to 100nm, for example. If the thickness of RL42 between the protrusions 42a is greater than 20nm, there is no influence of the tunneling effect and insulation can be ensured. In addition, if the height of the protrusion 42a is taken into consideration, when RL42 forms a protrusion 42a that protrudes upward than the RL42 between the protrusions 42a, the thickness of RL42 between the protrusions 42a is preferably less than 100nm. In addition, by setting the thickness of RL42 between the protrusions 42a to less than 100nm, the thickness of RL42 between the protrusions 42a can be made uniform.

[0246] AN43 and CA44 are provided separately from each other and cover at least a part of the side surfaces of the mutually adjacent convex portions 42a.

[0247] exist Fig. 27 In the example, AN43 is formed as an island-shaped pixel electrode for each pixel P, and is separated from AN43 of an adjacent pixel P on the upper surface of the protrusion 42a. Fig. 27 In the example shown, the AN 43 in the adjacent pixels P covers one side surface and the other side surface of the convex portion 42a, respectively. The AN 43 in each pixel P covers from a part of the upper surface of the convex portion 42a in each pixel P to a part of the side surface.

[0248] On the other hand, CA44 is a common electrode shared by the pixels P, and is provided from one side surface to the other side surface of the convex portion 42 a adjacent to the convex portion 42 a provided with AN43 .

[0249] AN43 is made of a conductive material and injects holes into EML48 via HTL46. CA44 is made of a conductive material and injects electrons into EML48 via ETL47.

[0250] The same conductive material as that of AN2 and CA7 can be used for AN43 and CA44. AN43 and CA44 may be formed of the same conductive material or may be formed of materials having different work functions.

[0251] HTL 46 (first carrier transport layer) is a layer for transporting holes from AN 43 to EML 48 and is in electrical contact with AN 43. ETL 47 (second carrier transport layer) is a layer for transporting electrons from CA 44 to EML 48 and is in electrical contact with CA 44.

[0252] HTL 46 covers at least a part of the side surface of convex portion 42a formed with AN43 via AN43. ETL 47 covers at least a part of the side surface of convex portion 42a formed with CA44 via CA44. HTL 46 and ETL 47 are respectively provided from one side surface to the other side surface of mutually adjacent convex portions 42a.

[0253] When viewed from above, HTL46 has Figure 1 The ETL 47 has the same shape as the convex portion 3a of the HTL 3 shown in FIG. Figure 1 The same shape as shown for ETL5.

[0254] In this embodiment, the four corners of the pixel P are also provided with Figure 1 The bank BK is the same as the bank BK shown in FIG. The bank BK insulates the HTL 46 and the ETL 47 at the four corners of the pixel P. The bank BK is opaque and functions as a separation wall for separating the pixels P (in other words, separating the light emitting elements 40) together with the HTL 46 and the ETL 47 covering the convex portions 42a. The bank BK is formed to have a height higher than the upper surface of the HTL 46 and the upper surface of the ETL 47.

[0255] The HTL 46 can be made of the same material as the HTL 3. The ETL 47 can be made of the same material as the ETL 5. The bank BK can be made of the same material as the bank BK according to the first embodiment.

[0256] On RL42 between the convex parts 42a, IL45 is provided in a manner to cover the respective edges of AN43 and CA44, and AN43 and CA44 cover the convex parts 42a. IL45 insulates the mutually adjacent AN43 and CA44. In addition, IL45 also functions as an edge cover of AN43 and CA44. Thus, it is possible to prevent the electric field from being concentrated on the edges of AN43 and CA44.

[0257] Between the convex parts 42a, HTL46 is formed on AN43 via IL45. The edge of HTL46 is overlapped on the edge of AN43 via IL45. In addition, between the convex parts 42a, ETL47 is formed on CA44 via IL45. The edge of ETL47 is overlapped on the edge of CA44 via IL45. Between the convex parts 42a, below HTL46 and ETL47, IL45 is formed so as to cover the entire upper surface of RL42 between the convex parts 42a.

[0258] According to the present embodiment, the IL45 covers the entire upper surface of the RL42 between the protrusions 42a, thereby forcibly flowing current in a direction parallel to the surface of the substrate 1. Therefore, according to the present embodiment, the light emitting element 40 can emit light uniformly in the planar direction.

[0259] IL45 can use the same insulating material as IL4. The insulation of AN43, CA44 and RE41 is ensured by RL42. Therefore, IL45 only needs to have a layer thickness of 2nm or more to form a continuous film. In addition, if the height of the convex portion 42a is considered, in order to form a convex portion 42a that protrudes upward from IL45, the layer thickness of IL45 is preferably 100nm or less. In addition, by making the layer thickness of IL45 less than 100nm, the layer thickness of IL45 can be made uniform.

[0260] The EML 48 is formed in the recess CP surrounded by the IL 45 , the HTL 46 , the ETL 47 , and the bank BK. In other words, the EML 48 is formed in the recess CP including the HTL 46 , the ETL 47 , and the bank BK on a portion of the sidewall.

[0261] HTL46 and ETL47 are not located above EML48, but are disposed opposite to each other with EML48 sandwiched therebetween in a plan view. Similarly, AN43 and CA44 are not located above EML48, but are disposed opposite to each other with EML48 sandwiched therebetween in a plan view.

[0262] When observed in cross section, the convex portion 42a has a positive cone shape. More specifically, the convex portion 42a has a trapezoidal cross-sectional shape with the upper end smaller than the lower end. Therefore, AN43, CA44, HTL46, and ETL47 covering the convex portion 42a each have a positive cone shape in a cross-sectional view and have an inclined surface along the side wall of the convex portion 42a.

[0263] Therefore, if Fig. 27 As shown in the box F5 surrounded by two dotted lines, a part of EML48 is formed to overlap a part of ETL47. Fig. 27 As shown in the frame F6 surrounded by two-dot chain lines, a part of the EML 48 is formed so as to overlap a part of the HTL 46 .

[0264] The EML 48 includes a light-emitting material, and emits light by recombination of electrons transported from the CA 44 and holes transported from the AN 43. The light-emitting material may be the same as that used for the EML 6.

[0265] <Method for Manufacturing Light Emitting Element 40 and Display Device 100>

[0266] Next, a method for manufacturing the light emitting element 40 and the display device 100 according to this embodiment will be described. Fig.28 This is a flowchart showing a part of the manufacturing process of the light emitting element 40 and the display device 100 according to the present embodiment in order of process.

[0267] In this embodiment, first, the substrate 1 as a support is prepared similarly to Embodiment 1. Then, RE 41 is formed on the substrate 1 in a solid state over the entire display region of the substrate 1 (step S31 , reflective electrode forming step).

[0268] RE41 can be formed in the same manner as AN2 in the first embodiment.

[0269] Next, RL42 having a plurality of protrusions 42a on the surface is formed on RE41 (step S32, resin layer forming step).

[0270] RL42 can be formed in the same manner as HTL3 in Embodiment 1. In this embodiment, instead of step S2 in Embodiment 1, a resin film to be RL42 is formed on RE41 in a solid surface. Next, as in step S3 in Embodiment 1, a mask for processing the surface of the resin film into a concave-convex shape is formed on the resin film as an etching mask. Next, as in step S4 in Embodiment 1, the surface of the resin film is etched by wet etching or dry etching, thereby processing the surface of the resin film into a concave-convex shape. Thereafter, the mask is removed. Thus, the RL42 is formed.

[0271] Next, AN43 and CA44 are formed so as to cover at least a part of the side surfaces of the mutually adjacent convex portions 42 a (step S33 , first electrode and second electrode forming step).

[0272] AN43 and CA44 can be formed simultaneously using the same material. AN43 and CA44 can be formed in the same manner as CA7 in Embodiment 1. Specifically, first, a conductive layer to become AN43 and CA44 is formed on RL42 in a whole-surface manner in a manner that covers the convex portion 42a. Next, an etching mask is formed on the conductive layer, and after the conductive layer is etched by wet etching or dry etching, the mask is removed. In addition, AN43 and CA44 can of course also be formed by printing, vapor deposition, CVD, etc.

[0273] As described above, by using the same material for AN43 and CA44, AN43 and CA44 can be formed at the same time. Therefore, the light emitting element 40 can be formed more easily in a shorter time.

[0274] However, the present embodiment is not limited thereto, and a conductive layer for adjusting the work function may be further formed on the conductive layer and patterned to thereby form AN43 and CA44 having different work functions.

[0275] Next, IL45 is formed on RL42 between the protrusions 42a so as to cover the respective edge portions of AN43 and CA44 that cover the protrusions 42a (step S34, insulating layer forming step).

[0276] In forming IL45 , similarly to IL4 , various conventionally known methods such as sputtering, CVD, and coating can be used as a method for forming an insulating layer.

[0277] Next, HTL46 is formed via AN43 to cover at least a portion of the side surface of the convex portion 42a formed with AN43 (step S35, first carrier transport layer forming step). Specifically, HTL46 is formed on IL45 to straddle the convex portion 42a formed with AN43.

[0278] Next, ETL 47 is formed via CA 44 to cover at least a portion of the side surface of the convex portion 41 a formed with CA 44 (step S36 , second carrier transport layer forming step). Specifically, ETL 47 is formed on IL 45 to straddle the convex portion 41 a formed with CA 44.

[0279] The HTL 46 and the ETL 47 can be formed using an etching mask by the same method as the HTL 3 and the ETL 5 in Embodiment 1. In addition, the order of step S35 and step S36 may be reversed.

[0280] Next, the bank BK is formed to have a height higher than the upper surfaces of the HTL 46 and the ETL 47 by the same method as the bank BK in Embodiment 1. Thus, a concave portion CP surrounded by the IL 45 , the HTL 46 , the ETL 47 , and the bank BK is formed in each pixel P.

[0281] Next, the EML 48 is formed in the concave portion CP (step S37 , light emitting layer forming step). The EML 48 can be formed in the same manner as the EML 6 in the first embodiment.

[0282] Thereafter, the light emitting element 40 is sealed by the sealing resin 21 and the sealing substrate 22 in the same manner as in Embodiment 1 (step S38 , sealing layer forming step). In this way, the display device 100 according to this embodiment is manufactured.

[0283] As described above, the light emitting element 40 according to the present embodiment includes AN43, HTL46, CA44, ETL47, and EML48. At least a portion of EML48 overlaps a portion of HTL46, and a portion of EML48 overlaps a portion of ETL47. In a plan view, HTL46 and ETL47 are disposed opposite to each other with EML48 interposed therebetween.

[0284] Therefore, according to the light emitting element 40, the same effect as that of the light emitting element 10 can be obtained. Therefore, in this embodiment, the same effect as that of the first embodiment can be obtained.

[0285] In addition, in this embodiment, HTL46 and ETL47 are aligned with each other in a plan view. Figure 1 The case where the convex portion 3a of the HTL3 and the ETL5 have the same shape is described as an example. However, it goes without saying that the HTL46 and the ETL47 may also have the same shape in a top view. Fig.12 or Fig.13 The convex portion 3a of the HTL3 shown has the same shape as that of the ETL5.

[0286] <Variation 1>

[0287] Fig.29 It is a cross-sectional view schematically showing the structure of a main part of a display device 100 according to this modification.

[0288] exist Fig.28 In the process, step S34 (insulating layer forming step) may be performed between step S35 (first carrier transport layer forming step) and step S36 (second carrier transport layer forming step) and step S37 (light emitting layer forming step).

[0289] Thus, after forming the HTL 46 and the ETL 47, by forming the IL 45 between the adjacent convex portions 42a, it is possible to manufacture Fig.29 The light emitting element 40 and the display device 100 are shown.

[0290] Fig.29 The light emitting element 40 and the display device 100 shown are similar to the light emitting element 40 and the display device 100 except for the following aspects. Fig. 27 The light emitting element 40 and the display device 100 shown are the same. In this modification, the edge of HTL46 is disposed on the edge of AN43 and in contact with the edge of AN43. In addition, the edge of ETL47 is disposed on the edge of CA44 and in contact with the edge of CA44. IL45 is disposed at a position higher than HTL46 and ETL47, and covers the edge of AN43, the edge of CA44, the edge of HTL46, and the edge of ETL47, respectively.

[0291] According to this modification, the electric field can be prevented from being concentrated only on the edge portions, and the current can flow in a direction parallel to the surface of the substrate 1. Therefore, the light emitting element 40 and the display device 100 that emit light uniformly in the planar direction can be manufactured.

[0292] <Variation 2>

[0293] Fig.30 It is a cross-sectional view schematically showing the structure of a main part of a display device 100 according to this modification.

[0294] exist Fig.28 In the process, step S34 (insulating layer forming step) may be performed between step S32 (resin layer forming step) and step S33 (first electrode and second electrode forming step).

[0295] According to this modification, by forming IL45 between adjacent convex portions 42a before forming AN43 and CA44, it is possible to manufacture Fig.30 The light emitting element 40 and the display device 100 are shown.

[0296] Fig.30 The light emitting element 40 and the display device 100 shown are similar to the light emitting element 40 and the display device 100 except for the following aspects. Fig. 27 The light emitting element 40 and the display device 100 shown are the same. In this modification, IL45 is arranged at a lower layer than AN43 and CA44, covering the edge of the protrusion 42a. The edge of AN43 and the edge of CA44 are arranged on IL45. The edge of HTL46 is arranged on the edge of AN43 in contact with the edge of AN43. In addition, the edge of ETL47 is arranged on the edge of CA44 in contact with the edge of CA44.

[0297] According to this modification, the electric field can be prevented from concentrating only on the edge of the convex portion 42a, and current can flow in a direction parallel to the surface of the substrate 1. Therefore, the light emitting element 40 and the display device 100 that emit light uniformly in the planar direction can be manufactured.

[0298] <Variation 3>

[0299] Fig.31 It is a cross-sectional view schematically showing the structure of a main part of a display device 100 according to this modification.

[0300] Fig.31 The light emitting element 40 and the display device 100 shown are similar to the light emitting element 40 and the display device 100 except for the following aspects. Fig. 27 The light emitting element 40 shown in the figure is the same as the display device 100. In this modification, AN43 and CA44 are light reflecting electrodes, respectively. In this modification, CA44, which is a common electrode, is extended between the protrusions 42a toward the edge of AN43, which is a pixel electrode, to the vicinity of the edge of AN43, instead of setting RE41. Therefore, in this modification, CA44 is extended on the bottom surface of the concave portion CP. IL45 is formed to cover the upper surface and edge of CA44 between the protrusions 42a and the edge of AN43, and to cover the entire protrusions 42a.

[0301] If the insulation between CA44 and AN43 can be ensured, the edge of CA44 and the edge of AN43 are preferably arranged as close as possible, and most preferably, they are opposite to each other at a minimum distance to ensure the insulation between CA44 and AN43. Therefore, in order to make the distance between the edge of CA44 and the edge of AN43 have the same insulation in the vertical and horizontal directions, it is preferred that the typical thickness of IL45 is at least 20nm. In addition, as the distance between the edge of CA44 and the edge of AN43 increases, it is easy to produce a depression directly above the edge of CA44 and the edge of AN43 when IL45 is formed. Therefore, from the perspective of maintaining the uniformity of IL45, the distance is preferably less than 100nm.

[0302] In this modification, since RE41 is not required, the reflective electrode forming step S31 is not performed, and RL42 is formed on the substrate 1 in step S32 (resin layer forming step). Then, in step S33 (first electrode and second electrode forming step), CA44 is extended to be formed between the adjacent convex portions 42a. Fig.28 Steps S34 to S38 are shown. In this way, the display device 100 according to this modification can be manufactured.

[0303] As described above, according to this modification, the light emitting element 40 capable of easily extracting light from the upper surface direction of the EML 48 can be manufactured without separately forming the RE 41 .

[0304] In addition, in this modification, the case where AN43 is a pixel electrode and CA44 is a common electrode is described as an example. However, as described above, CA44 may also be a pixel electrode and AN43 may also be a common electrode. In addition, instead of CA44, AN43 may also be extended between the convex portions 42a toward the edge of CA44 to the vicinity of the edge of CA44.

[0305] <Variation 4>

[0306] Fig.32 It is a cross-sectional view schematically showing the structure of the main part of the light emitting element 50 according to the present modification.

[0307] The light emitting element 50 is similar to the light emitting element 30 according to the third embodiment. The HTL 46 and the ETL 47 may have concentric shapes with one of them being the center and the other surrounding the periphery of the one in a plan view.

[0308] exist Fig.32 In the illustrated example, the case where the ETL 47 has a concentric shape with the HTL 46 as the center is illustrated. Fig.32In the light emitting element 50 shown, the HTL 46 is located at the center of the pixel P, and the ETL 47 surrounds the outer periphery of the HTL 46 in a frame shape so as to surround the HTL 46. The ETL 47 is extended toward the adjacent pixel P.

[0309] The outer shape of the convex portion 42a covered by HTL46 and the outer shape of the convex portion 42a covered by ETL47 may also have a similar shape when viewed from above. In addition, when viewed from above, the outer shape of the pixel P has a shape similar to the outer shape of the convex portion 42a. The outer shape of the convex portion 42a and the outer shape of the pixel P may be any one of a circle, a longitudinal ellipse, a transverse ellipse, and a regular polygon (a regular n-sided shape, where n is an integer greater than 3). However, in this variation, a regular pentagon with n=5 and a polygon with n being an integer multiple of 5 cannot be arranged to form a plurality of pixels P in a manner without gaps between the pixels P. Therefore, it is preferred that n≠(an integer multiple of 5).

[0310] In addition, in a plan view, the HTL 46 and the ETL 47 in the pixel P may respectively have convex portions protruding into the concave portion CP in a comb-teeth shape on surfaces facing each other.

[0311] In the light emitting element 50 according to this modification, similarly to the fourth embodiment, the lateral electric field is evenly distributed around the periphery, and thus light can be emitted uniformly in the planar direction.

[0312] In addition, as mentioned above, Fig.32 In the example shown, AN43 is a pixel electrode, CA44 is a common electrode, and ETL47 has a concentric shape centered on HTL46. However, it goes without saying that CA44 can also be a pixel electrode, AN43 can also be a common electrode, and HTL46 can also have a concentric shape centered on ETL47.

[0313] The present disclosure is not limited to the above-mentioned embodiments, and various changes can be made within the scope of the claims. The embodiments obtained by appropriately combining the technical solutions disclosed in different embodiments are also included in the technical scope of the present disclosure. Moreover, by combining the technical means disclosed in each embodiment, new technical features can be formed.

[0314] Description of Reference Numerals

[0315] 2. 43 AN (anode)

[0316] 3.46 HTL (hole transport layer)

[0317] 3a, 3a3, 3b, 5d, 42a convex part

[0318] 3a1, 4a, 5a vertical line

[0319] 4b, 5b horizontal line

[0320] 3a2, 4c, 5c branch line (comb teeth)

[0321] 4. 45 IL (insulation layer)

[0322] 5.47 ETL (Electron Transport Layer)

[0323] 6.48 EML

[0324] 7.44 CA (cathode)

[0325] 10, 10R, 10G, 10B, 30, 40, 40R, 40G, 40B, 50 light emitting elements

[0326] 22 Sealing substrate (sealing layer)

[0327] 41 RE (reflective electrode)

[0328] 42 RL (resin layer)

[0329] 100 Display device

Claims

1. A light emitting element, characterized in that: have: a first electrode; a first carrier transport layer electrically contacting the first electrode; a second electrode disposed separately from the first electrode; a second carrier transport layer electrically contacting the second electrode; as well as Luminescent layer, At least a portion of the light-emitting layer overlaps a portion of the first carrier transport layer, and a portion of the light-emitting layer overlaps a portion of the second carrier transport layer. In a plan view, the first carrier transport layer and the second carrier transport layer are arranged opposite to each other with the light emitting layer sandwiched therebetween; The light emitting element further includes an insulating layer disposed on the first carrier transport layer. The first electrode is a light reflecting electrode, The first carrier transport layer is formed on the first electrode and has a convex portion protruding upward. The second carrier transport layer is formed on the insulating layer so as to protrude upward so as to face the convex portion in a plan view. The light emitting layer is formed in the concave portion, and a portion of a side wall of the concave portion includes the convex portion and the second carrier transport layer.

2. The light emitting element according to claim 1, characterized in that The bottom surface of the recess is formed by the insulating layer.

3. The light emitting element according to claim 1 or 2, characterized in that: The second electrode is formed to be in contact with at least a portion of an upper surface of the second carrier transport layer and not in contact with the light emitting layer.

4. The light emitting element according to claim 1 or 2, characterized in that: The second electrode is formed so as to overlap the second carrier transport layer so that a lower surface of the second electrode has the same shape as an upper surface of the second carrier transport layer.

5. A light emitting element, characterized in that: have: a first electrode; a first carrier transport layer in electrical contact with the first electrode; a second electrode spaced apart from the first electrode; a second carrier transport layer in electrical contact with the second electrode; as well as Luminescent layer, At least a portion of the light-emitting layer overlaps a portion of the first carrier transport layer, and a portion of the light-emitting layer overlaps a portion of the second carrier transport layer. In a plan view, the first carrier transport layer and the second carrier transport layer are arranged opposite to each other with the light emitting layer sandwiched therebetween; The light emitting element further comprises a resin layer having a plurality of convex portions, The first electrode and the second electrode cover at least a portion of the side surfaces of the convex portions adjacent to each other, The first carrier transport layer covers at least a portion of a side surface of the protrusion on which the first electrode is formed, via the first electrode. The second carrier transport layer covers at least a portion of a side surface of the protrusion on which the second electrode is formed, via the second electrode. The light emitting layer is formed in the concave portion, and a portion of a side wall of the concave portion includes the convex portion and the second carrier transport layer.

6. The light emitting element according to claim 5, characterized in that further comprising a reflective electrode, The resin layer is formed on the reflective electrode.

7. The light emitting element according to claim 5, characterized in that The first electrode and the second electrode are light reflecting electrodes, At least one of the first electrode and the second electrode extends between the protrusions adjacent to each other.

8. The light emitting element according to claim 1 or 5, characterized in that: The second carrier transport layer is made of a semiconductor.

9. The light emitting element according to claim 1 or 5, characterized in that: The first carrier transport layer is made of a semiconductor.

10. The light emitting element according to claim 8, characterized in that The first carrier transport layer and the second carrier transport layer are opaque.

11. The light emitting element according to claim 9, characterized in that The first carrier transport layer and the second carrier transport layer are opaque.

12. The light emitting element according to any one of claims 1, 2, 5 to 7, characterized in that: A sealing layer is disposed on the light emitting layer and adjacent to the light emitting layer.

13. The light emitting element according to any one of claims 1, 2, 5 to 7, characterized in that: The first carrier transport layer and the second carrier transport layer are formed in a comb shape in a plan view, and are alternately arranged so that the comb teeth of the layers mesh with each other.

14. The light emitting element according to any one of claims 1, 2, 5 to 7, characterized in that: The first carrier transport layer and the second carrier transport layer have concentric shapes in which one is the center and the other surrounds the periphery of the one in a plan view.

15. A display device, characterized in that: A light-emitting element according to any one of claims 1, 2, and 5 to 7.

16. A method for manufacturing a light-emitting element, the light-emitting element comprising: a first electrode; a first carrier transport layer electrically contacting the first electrode; a second electrode disposed separately from the first electrode; a second carrier transport layer electrically contacting the second electrode; as well as Luminescent layer, at least a portion of the light-emitting layer overlaps a portion of the first carrier transport layer, and a portion of the light-emitting layer overlaps a portion of the second carrier transport layer; In a plan view, the first carrier transport layer and the second carrier transport layer are disposed opposite to each other with the light emitting layer sandwiched therebetween. The method for manufacturing the light emitting element is characterized by comprising: forming the first carrier transport layer; forming an insulating layer on the first carrier transport layer; forming the second carrier transport layer apart from the first carrier transport layer; A step of forming the light emitting layer in a space between the first carrier transport layer and the second carrier transport layer in a plan view; and a step of forming the first electrode before the step of forming the first carrier transport layer, The first electrode is a light reflecting electrode, In the step of forming the first carrier transport layer, the first carrier transport layer is formed on the first electrode in such a manner that the first carrier transport layer has a convex portion protruding upward; In the step of forming the second carrier transport layer, the second carrier transport layer is formed on the insulating layer so as to protrude upward so as to face the convex portion in a plan view; The light emitting layer is formed in a concave portion, and the concave portion is defined by a side wall including the convex portion and the second carrier transport layer.

17. A method for manufacturing a light-emitting element, the light-emitting element comprising: a first electrode; a first carrier transport layer electrically contacting the first electrode; a second electrode disposed separately from the first electrode; a second carrier transport layer electrically contacting the second electrode; as well as Luminescent layer, at least a portion of the light-emitting layer overlaps a portion of the first carrier transport layer, and a portion of the light-emitting layer overlaps a portion of the second carrier transport layer; In a plan view, the first carrier transport layer and the second carrier transport layer are disposed opposite to each other with the light emitting layer sandwiched therebetween. The method for manufacturing the light emitting element is characterized by comprising: forming the first carrier transport layer; forming the second carrier transport layer apart from the first carrier transport layer; A step of forming the light-emitting layer in a space between the first carrier transport layer and the second carrier transport layer when viewed from above; The method for manufacturing the light emitting element further comprises: a step of forming a resin layer having a plurality of protrusions; and forming the first electrode and the second electrode so as to cover at least a portion of the side surfaces of the protrusions adjacent to each other, In the process of forming the first carrier transport layer, the first carrier transport layer is formed via the first electrode in a manner that covers at least a portion of the side surface of the protrusion formed with the first electrode, and in the process of forming the second carrier transport layer, the second carrier transport layer is formed via the second electrode in a manner that covers at least a portion of the side surface of the protrusion formed with the second electrode.

18. The method for manufacturing a light emitting element according to claim 17, characterized in that: Before forming the resin layer, a step of forming a reflective electrode is included; In the step of forming the resin layer, the resin layer is formed on the reflective electrode.

19. The method for manufacturing a light emitting element according to claim 17, wherein: The first electrode and the second electrode are light reflecting electrodes, In the step of forming the first electrode and the second electrode, at least one of the first electrode and the second electrode is formed so as to extend between the protrusions adjacent to each other.

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