Display device

Abstract

The display device comprises: a supporting substrate (10), a thin film transistor layer (4), a light emitting element layer (5) having a plurality of light emitting elements (5R, 5G, 5B) having mutually different luminous colors, and a sealing layer (6) for sealing the light emitting element layer (5), wherein the light emitting element (5R, 5G, 5B) comprises a first electrode (22), a hole transport layer (24), a light emitting layer (25R, 25G, 25B), an electron transport layer (27R, 27G, 27B) and a second electrode (28), and the electron transport layer (27R, 27G, 27B) comprises oxide nanoparticles, a binder resin and a photopolymerization initiator.

Description

Technical Field

[0001] The present invention relates to a display device having a light-emitting element, wherein the light-emitting element has a hole transport layer (HTL), a light-emitting layer (EMSsive Layer, EML), and an electron transport layer (ETL). Background Art

[0002] Patent Document 1 discloses a display device including a light-emitting element in which a cathode and an electron transport layer common to a plurality of pixel electrodes are formed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Publication No. 2017-183510 Summary of the invention

[0006] Technical Problems to be Solved by the Invention

[0007] Generally, the electron injection efficiency from the electron transport layer of the light-emitting element to the light-emitting layer varies depending on the types of the light-emitting layer and the electron transport layer. As in the display device described in Patent Document 1, when a cathode and an electron transport layer are shared by a plurality of light-emitting elements having light-emitting layers of different types, it is difficult to optimize the electron injection efficiency from the electron transport layer to the light-emitting layer among the plurality of light-emitting elements.

[0008] Technical solutions for solving technical problems

[0009] The display device of the present invention is a display device including a display area having a plurality of pixels and a frame area around the display area, wherein the display area is provided with a substrate, a thin film transistor layer, a light-emitting element layer and a sealing layer in sequence, the light-emitting element layer having a plurality of light-emitting elements having different luminous colors, the sealing layer sealing the light-emitting element layer, the light-emitting element including a first electrode, a hole transport layer, a light-emitting layer, an electron transport layer and a second electrode in sequence from the substrate side, either one of the first electrode and the second electrode being an island electrode provided for each light-emitting element, the other of the first electrode and the second electrode being a common electrode shared with a plurality of the light-emitting elements, and the electron transport layer including oxide nanoparticles, an adhesive resin and a photopolymerization initiator.

[0010] Beneficial Effects

[0011] According to one aspect of the present invention, even when the type of the light-emitting layer differs between light-emitting elements, it is possible to more easily optimize the difference in electron injection efficiency between the light-emitting elements. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is an enlarged top view showing an example of the configuration of main parts in the display area of ​​the display device according to Embodiment 1.

[0013] Figure 2 The following is an example of the configuration of the main parts in the display area of ​​the above-mentioned display device. Figure 1 A side cross-sectional view along line BB is shown.

[0014] Figure 3 is a perspective view of the upper surface of the display device.

[0015] Figure 4 The following is an example of the main structure of the frame area of ​​the display device. Figure 3 Side cross-sectional view along line CC shown.

[0016] Figure 5 This is an energy diagram for explaining an example of energy levels in the main structure of the light-emitting element layer of the above-mentioned display device.

[0017] Figure 6 is a flowchart showing a method for manufacturing the above-mentioned display device.

[0018] Figure 7 It is a side cross-sectional view showing a specific configuration example of Modification 1 of the above-mentioned display device.

[0019] Figure 8 It is a side cross-sectional view showing a specific configuration example of Modification 2 of the above-mentioned display device.

[0020] Fig. 9 It is a side cross-sectional view showing a specific configuration example of Modification 3 of the above-mentioned display device.

[0021] Fig.10 It is a side cross-sectional view showing a specific configuration example of Modification 4 of the above-mentioned display device.

[0022] Fig.11 This is a side cross-sectional view showing a specific configuration example of a display device according to Embodiment 2.

[0023] Fig.12 This is a side cross-sectional view showing a specific configuration example of a display device according to Embodiment 3.

[0024] Fig.13 This is a side cross-sectional view showing a specific configuration example of a display device according to a fourth embodiment. DETAILED DESCRIPTION

[0025] [Implementation Method 1]

[0026] In the following content, "the same layer" means formed by the same material in the same process. In addition, "lower layer" refers to a layer formed in a process before the comparison object layer, and "upper layer" refers to a layer formed in a process after the comparison object layer. In addition, in this specification, the direction from the lower layer to the upper layer of the display device is called upward.

[0027] Figure 1 This is an enlarged top view showing an example of the configuration of main parts in the display area DA of the display device 2A according to the first embodiment. Figure 2 The following is an example of the configuration of the main parts in the display area DA of the display device 2A. Figure 1 A side cross-sectional view along line BB is shown. Figure 3 2A is a perspective view showing an upper surface of the display device 2A. Figure 4 FIG. 1 is a diagram showing an example of a main part configuration of the frame region NA of the display device 2A. Figure 3 The side cross-section of the CC line is shown. Figure 1 In the figure, the hole transport layer, the second electrode, the sealing layer, etc. described later are omitted. Figure 3 In the figure, the specific structure of the sealing layer and the specific structure of the TFT layer described later, the barrier layer and the resin layer are omitted.

[0028] like Figure 3 As shown in FIG. 1 , the display device 2A according to the present embodiment includes a display area DA and a frame area NA adjacent to the periphery of the display area DA. Figure 1 As shown in the example, a red sub-pixel including a red light-emitting element 5R, a green sub-pixel including a green light-emitting element 5G, and a blue sub-pixel including a blue light-emitting element 5B are provided in the display area DA. In addition, these red sub-pixels, green sub-pixels, and blue sub-pixels constitute one pixel, and the display area DA includes a plurality of pixels, and information is displayed through these pixels.

[0029] In addition, Figure 1 and Figure 2In the embodiment, the electron transport layer 27R included in the red light emitting element 5R, the electron transport layer 27G included in the green light emitting element 5G, and the electron transport layer 27B included in the blue light emitting element 5B are respectively composed of materials that meet the corresponding VBM (Valence Band Maximum) and the corresponding CBM (Conduction Band Minimum) of the red light emitting layer 25R included in the red light emitting element 5R, the green light emitting layer 25G included in the green light emitting element 5G, and the blue light emitting layer 25B included in the blue light emitting element 5B (see below for details). The above-mentioned VBM is equivalent to HOMO (Highest Occupied Molecular Orbital). The above-mentioned CBM is equivalent to LUMO (Lowest Unoccupied Molecular Orbital).

[0030] like Figure 2 As shown, the display device 2A involved in this embodiment includes a support substrate 10, a thin film transistor layer 4, a light emitting element layer 5, and a sealing layer 6 in order from the bottom layer. The display device 2A may also include a functional film having an optical compensation function, a touch sensor function, a protective function, etc. on the upper layer of the sealing layer 6. In addition, a resin layer and a barrier layer (not shown) are formed between the thin film transistor layer 4 and the support substrate 10.

[0031] The support substrate 10 may be a flexible substrate such as a PET film or a rigid substrate such as a glass substrate. The material of the resin layer 12 is polyimide.

[0032] The barrier layer is a layer that prevents foreign matter such as water and oxygen from penetrating the thin film transistor layer 4 and the light emitting element layer 5 when the display device 2A is used. In addition, the barrier layer can be composed of a silicon oxide film, a silicon nitride film, or a silicon oxynitride film formed by, for example, CVD, or a stacked film of these layers.

[0033] The thin film transistor layer 4 includes a source wiring SH and a planarization film 21. In addition, regarding a specific configuration example of the thin film transistor layer 4, the following will be used. Figure 8 etc. for explanation.

[0034] The source wiring SH may also include at least one of aluminum (Al), tungsten (W), molybdenum (Mo), tantalum (Ta), chromium (Cr), titanium (Ti), and copper (Cu). In addition, the source wiring SH is composed of a single layer film or a stacked film of the above metals. In particular, in the present embodiment, the source wiring SH includes Al.

[0035] like Figure 2As shown, the light-emitting element layer 5 (for example, an organic light-emitting diode layer) includes: a first electrode 22 (anode), a hole injection layer 41, a hole transport layer 24, a light-emitting layer 25 including a red light-emitting layer 25R, a green light-emitting layer 25G and a blue light-emitting layer 25B, an edge cover 23 covering the edge of the first electrode 22, an auxiliary wiring 26, electron transport layers 27R, 27G, 27B and a second electrode 28 (cathode).

[0036] In this embodiment, if Figure 1 As shown, the light emitting element layer 5 includes: a red light emitting element 5R including a red light emitting layer 25R, a green light emitting element 5G including a green light emitting layer 25G, and a blue light emitting element 5B including a blue light emitting layer 25B as multiple light emitting elements.

[0037] The first electrode 22 is provided at a position overlapping with the planarization film 21 and the contact hole 21c when viewed from above. The first electrode 22 is electrically connected to the source wiring SH via the contact hole 21c. Therefore, the signal in the thin film transistor layer 4 is supplied to the first electrode 22 via the source wiring SH. The thickness of the first electrode 22 may also be, for example, 100 nm. In the present embodiment, the first electrode 22 is, for example, composed of ITO (Indium Tin Oxide) and Ag or an alloy containing Ag, and has light reflectivity.

[0038] In this embodiment, the hole transport layer 24 is formed on the hole injection layer 41. The hole transport layer 24 is an inorganic hole transport layer, and contains, for example, NiO or MgNiO as a hole transport material.

[0039] The light emitting layer 25 is formed for each of the plurality of light emitting elements at a position overlapping the first electrode 22. In this embodiment, the light emitting layer 25 includes the red light emitting layer 25R, the green light emitting layer 25G, and the blue light emitting layer 25B described above for each of the plurality of light emitting elements.

[0040] In this embodiment, the red light emitting layer 25R, the green light emitting layer 25G, and the blue light emitting layer 25B emit red light, green light, and blue light, respectively. That is, the red light emitting element 5R, the green light emitting element 5G, and the blue light emitting element 5B are light emitting elements that emit red light, green light, and blue light, respectively.

[0041] Here, blue light is light having a central wavelength of emission in a wavelength band of 400 nm to 500 nm. In addition, green light is light having a central wavelength of emission in a wavelength band of, for example, more than 500 nm to 600 nm. In addition, red light is light having a central wavelength of emission in a wavelength band of, for example, more than 600 nm to 780 nm.

[0042] The edge cover 23 is an organic insulating film, for example, containing an organic material such as polyimide, acrylic acid, etc. The edge cover 23 is formed at a position covering the edge of each first electrode 22. In addition, the edge cover 23 has an opening 23h corresponding to each of the plurality of light-emitting elements, and a portion of each first electrode 22 is exposed from the edge cover 23. Therefore, the edge cover 23 divides each pixel of the display device 2A into a red sub-pixel, a green sub-pixel, and a blue sub-pixel.

[0043] In this embodiment, the auxiliary wiring 26 is formed at a position overlapping with the edge cover 23. Figure 3 As shown, the auxiliary wiring 26 is arranged in a lattice shape. In this embodiment, the auxiliary wiring 26 is in contact with the sealing layer 6 side of the second electrode 28. In addition, in this embodiment, the auxiliary wiring 26 is not limited to Figure 3 As shown, a plurality of linear auxiliary wirings 26 arranged at substantially equal intervals are arranged to intersect each other vertically. For example, as in the PenTile arrangement, the intervals between adjacent auxiliary wirings 26 may be different depending on the position, and the auxiliary wirings 26 may also intersect each other obliquely.

[0044] The material of the auxiliary wiring 26 may also be silver. Silver is a metal layer of the thin film transistor layer 4, and is generally a material used for the bottom plate of the display device. Since the auxiliary wiring 26 is made of silver, the material used to form the back plate can be used when forming the auxiliary wiring 26. In addition, the auxiliary wiring 26 may also have a single Al or Cu structure, a Ti / Al / Ti stacked structure, or a W / Ta stacked structure.

[0045] The electron transport layer 27 is formed for each of the plurality of light-emitting elements at a position overlapping with each of the first electrodes 22. In the present embodiment, the electron transport layer 27 includes an electron transport layer 27R for the red light-emitting element 5R, an electron transport layer 27G for the green light-emitting element 5G, and an electron transport layer 27B for the blue light-emitting element 5B.

[0046] Figure 5 2A is an energy diagram for explaining an example of energy levels in the main structure of the light emitting element layer 5 of the display device 2A. Figure 2As shown, in the case where the light-emitting layer 25 in the structure in which the hole injection layer 41, the hole transport layer 24, the light-emitting layer 25 and the electron transport layers 27R, 27G, 27B are stacked in order from the bottom layer and colored into three colors: a red light-emitting layer 25R, a green light-emitting layer 25G and a blue light-emitting layer 25B, the light-emitting materials VBM and CBM of the three-color light-emitting layers 25R, 25G, 25B are different from each other. Therefore, if the structure other than the light-emitting layers 25R, 25G, 25B is composed of the same material for all three colors, then due to the difference in the light-emitting materials of the three-color light-emitting layers 25R, 25G, 25B, the light-emitting brightness and external quantum efficiency (EQE) will decrease, and the chromaticity of the light-emitting layers 25R, 25G, 25B will decrease. Figure 5 In the example shown, the VBM of the red light-emitting layer 25R is 3.4 and the CBM is 5.4, the VBM of the green light-emitting layer 25G is 3.1 and the CBM is 5.4, and the VBM of the blue light-emitting layer 25B is 2.7 and the CBM is 5.4. The VBMs of the red light-emitting layer 25R, the green light-emitting layer 25G and the blue light-emitting layer 25B are different from each other.

[0047] The electron transport layers 27R, 27G, and 27B of this embodiment are composed of materials suitable for the corresponding red light emitting layer 25R, green light emitting layer 25G, and blue light emitting layer 25B. Examples thereof are shown below (Table 1).

[0048] [Table 1]

[0049]

[0050] The electron transport layer (ETL) 27R corresponding to the red light emitting layer (EML) 25R is composed of, for example, ZnO containing the reagent (N-12). The CBM of the electron transport layer 27R is 4.3 eV and the VBM is 7.2 eV. The CBM of the corresponding red light emitting layer 25R is 3.4 eV and the VBM is 5.4 eV.

[0051] The hole transport layer (HTL) 24 is made of, for example, TFB, and the hole injection layer (HIL) 41 is made of, for example, PEDOT:PSS. TFB is poly[(9,9'-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butyl))diphenylamine)].

[0052] The electron transport layer 27G corresponding to the green light emitting layer 25G is composed of, for example, ZnO containing the reagent (N-11). The CBM of the electron transport layer 27G is 3.9 eV, and the VBM is 7.2 eV. The CBM of the corresponding green light emitting layer 25G is 3.1 eV, and the VBM is 5.4 eV.

[0053] The electron transport layer 27B corresponding to the blue light emitting layer 25B is made of, for example, ZnMgO. The CBM of the electron transport layer 27B is 3.4 eV and the VBM is 7.2 eV. The CBM of the corresponding blue light emitting layer 25B is 2.7 eV and the VBM is 5.4 eV.

[0054] As the monomer of the binder resin, N-vinyl-2-pyrrolidone was used, and as the photopolymerization initiator, 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone was used.

[0055] In this way, the electron transport layer 27R material that matches the CBM and VBM of the red light-emitting layer 25R is selected, the electron transport layer 27G material that matches the CBM and VBM of the green light-emitting layer 25G is selected, and the electron transport layer 27B material that matches the CBM and VBM of the blue light-emitting layer 25B is selected. Then, the electron transport layers 27R, 27G, and 27B composed of materials suitable for the light-emitting layers of each color are coated by photolithography. The materials of each electron transport layer 27R, 27G, and 27B include oxide nanoparticles such as ZnO, ZnMgO, and LiZnO as electron transport materials, monomer resins (binder resins), photopolymerization initiators, and the like.

[0056] For example, the monomer resin is a styrene derivative, acrylonitrile, acrylate, acrylamide derivative, N-vinyl pyrrolidone, α-olefins, vinyl ethers, etc. as a monosubstituted ethylene compound (vinyl compound); a methacrylate, methacrylamide derivatives, etc. as a 1,1-disubstituted ethylene (vinylidene compound); and a 1,3-butadiene, isoprene, etc. as a diene compound.

[0057] In addition, for example, the photopolymerization initiator is acetophenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-ethoxy-2-phenylacetophenone, etc. as an acetophenone-based compound, benzophenone, tetramethyl Michler's ketone, etc. as a benzophenone-based compound, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone as a propiophenone-based compound, and in addition, 2,2'-azobis(2-methylpropylamidine) dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, etc.

[0058] The photopolymerization initiators involved in these embodiments do not generate acid when the photopolymerization (initiation) treatment is performed by UV irradiation as light irradiation. Therefore, when the above-mentioned photopolymerization (initiation) treatment is performed, the light-emitting element will not be damaged by the above-mentioned acid. In this way, the photopolymerization initiator involved in this embodiment includes a compound that does not generate acid during the light irradiation phase for initiating the polymerization reaction.

[0059] In addition, by adjusting the weight ratio of the monomer resin or changing the monomer resin, the film thickness and mobility of the electron transport layers 27R, 27G, and 27B suitable for the materials of the red light emitting layer 25R, the green light emitting layer 25G, and the blue light emitting layer 25B can be adjusted. The electron transport layers 27R, 27G, and 27B can be uniformly coated by separate coating using photolithography.

[0060] Other examples are shown in the following (Table 2). In other examples, VBM and CBM are different depending on the particle size of ZnO.

[0061] [Table 2]

[0062]

[0063] The electron transport layer 27R corresponding to the red light emitting layer 25R is composed of ZnO with a particle size of 5.5 nm. The CBM of the electron transport layer 27R is 3.8 eV and the VBM is 7.2 eV.

[0064] The electron transport layer 27G corresponding to the green light emitting layer 25G is composed of ZnO with a particle size of 3.2 nm. The CBM of the electron transport layer 27G is 3.2 eV and the VBM is 7.2 eV.

[0065] The electron transport layer 27B corresponding to the blue light emitting layer 25B is composed of ZnO with a particle size of 2.6 nm. The CBM of the electron transport layer 27B is 2.7 eV and the VBM is 7.2 eV.

[0066] In this embodiment, by making the materials of each electron transport layer 27R, 27G, 27B different between the different red light-emitting elements 5R, green light-emitting elements 5G and blue light-emitting elements 5B, the CBM of the electron transport layers 27R, 27G, 27B in each light-emitting element can be made different.

[0067] For example, the electron transport layer 27R may include ZnO nanoparticles as oxide nanoparticles. Also, the electron transport layer 27G may include MgZnO nanoparticles as oxide nanoparticles. Furthermore, the electron transport layer 27B may include LiZnO nanoparticles as oxide nanoparticles.

[0068] In addition, in this embodiment, the VBM and CBM of the electron transport layers 27R, 27G, and 27B may be different in pixels, and the electron transport layers 27R, 27G, and 27B may have the same material. For example, in this embodiment, the electron transport layers 27R, 27G, and 27B may have the same oxide nanoparticle material between the different red light-emitting elements 5R, green light-emitting elements 5G, and blue light-emitting elements 5B. Here, by making the particle size of the oxide nanoparticles of the electron transport layers 27R, 27G, and 27B different, the band gap of each electron transport layer 27 can be made different.

[0069] For example, the electron transport layers 27R, 27G, and 27B may have ZnO nanoparticles as oxide nanoparticles in any light-emitting element. Here, the particle size of the ZnO nanoparticles of the electron transport layer 27R may be larger than the particle size of the ZnO nanoparticles of the electron transport layer 27G, and the particle size of the ZnO nanoparticles of the electron transport layer 27G may be larger than the particle size of the ZnO nanoparticles of the electron transport layer 27B. Specifically, the particle size of the ZnO nanoparticles of the electron transport layer 27R is preferably greater than 5 nm and less than 8 nm, the particle size of the ZnO nanoparticles of the electron transport layer 27G is preferably greater than 3 nm and less than 5 nm, and the particle size of the ZnO nanoparticles of the electron transport layer 27B is preferably greater than 1.5 nm and less than 3 nm.

[0070] Moreover, for example, in this embodiment, the band gaps of the electron transport layers 27R, 27G, and 27B can be made different by making the composition ratios of the oxide nanoparticles in the electron transport layers 27R, 27G, and 27B different between the different red light emitting elements 5R, green light emitting elements 5G, and blue light emitting elements 5B. For example, when x is a real number greater than 0 and less than 1, the electron transport layers 27R, 27G, and 27B can have Mg x Zn 1-x Here, the value of x may be gradually increased in the order of the electron transport layer 27R, the electron transport layer 27G, and the electron transport layer 27B.

[0071] Specifically, in the electron transport layer 27R, the value of x may be greater than or equal to 0 and less than 0.1, in the electron transport layer 27G, the value of x may be greater than or equal to 0.1 and less than 0.3, and in the electron transport layer 27B, the value of x may be greater than or equal to 0.3 and less than 0.5.

[0072] like Figure 2As shown, the second electrode 28 is formed on the upper layer of the electron transport layer 27 as a common electrode shared by a plurality of light-emitting elements. In addition, the second electrode 28 has metal nanowires and has high light transmittance. The metal nanowires provided by the second electrode 28 may be, for example, silver nanowires. In addition, the second electrode 28 may also have conductive metal nanowires such as gold nanowires, aluminum nanowires, or copper nanowires. Moreover, the second electrode 28 is electrically connected to the auxiliary wiring 26 formed on the second electrode 28.

[0073] In this embodiment, the material of the second electrode 28 may also be a mixed material containing a silver nanowire dispersion. In addition, the mixed material may also contain an adhesive, a dispersant or other additives. Moreover, the material of the second electrode 28 is not limited to metal nanowires, and a transparent electrode film such as ITO may also be used.

[0074] The sealing layer 6 prevents foreign matter such as water and oxygen from penetrating into the light emitting element layer 5 .

[0075] Next, refer to Figure 3 and Figure 4 Each configuration in the frame area NA around the display area DA will be described.

[0076] like Figure 4 As shown, the display device 2A may include a support substrate 10, a resin layer 12, a barrier layer 3, a thin film transistor layer 4, and a sealing layer 6 in the frame region NA. Figure 4 The dummy bank DB is shown as being formed of the edge mask 23. The dummy bank DB can be used as a spacer and abuts against a CVD mask or the like for forming a common layer in the display area DA.

[0077] Furthermore, the display device 2A may include a Figure 3 and Figure 4 The first bank BK1 formed by the edge cover 23 and the second bank BK2 formed by the planarization film 21 and the edge cover 23 are shown. The first bank BK1 and the second bank BK2 are formed in a frame shape around the display area DA. The first bank BK1 and the second bank BK2 restrict the wetting and diffusion of the organic sealing film 32 caused by the organic sealing film 32 of the sealing layer 6 applied on the upper layer. For example, Figure 4 In the embodiment, the first bank BK1 abuts against the end of the organic sealing film 32 , thereby restricting the wetting and diffusion of the organic sealing film 32 .

[0078] like Figure 3 and Figure 4 As shown in FIG. 2 , the display device 2A includes a trunk wiring 34 between the planarization film 21 and the second electrode 28 in the frame region NA. The trunk wiring 34 is the same layer as the auxiliary wiring 26 and is made of the same material as the auxiliary wiring 26. Figure 3As shown, the auxiliary wiring 26 branches from the main wiring 34 and extends from the frame area NA to the display area DA. As described above, the auxiliary wiring 26 branched from the main wiring 34 is formed in a lattice shape at a position overlapping the edge cover 23 in the display area DA.

[0079] like Figure 3 and Figure 4 As shown, in the frame area NA, a slit 35 as an opening of the planarization film 21 may be formed at a portion of the periphery surrounding the display area DA. By forming thin film transistors of the thin film transistor layer 4 on the display area DA side of the slit 35 and the periphery of the display device 2A, a Figure 3 and Figure 4 The gate driver monolithic GD shown in FIG.

[0080] Here, if Figure 4 As shown in FIG. 1 , the trunk wiring 34 extends together with the second electrode 28 to the periphery of the display device 2A including the inside of the slit 35 and closer to the slit 35. Figure 4 As shown, a conductive film 36 made of the same material and the same layer as the first electrode 22 is formed in the frame area NA. The conductive film 36 extends from the side closer to the display area DA than the slit 35 on the frame area NA, through the inside of the slit 35, to the peripheral side closer to the display device 2A than the slit 35. Therefore, the trunk wiring 34 and the conductive film 36 are electrically connected at a position including the inside of the slit 35.

[0081] The conductive film 36 further extends to a position overlapping the first bank BK1 and the second bank BK2. At the position overlapping the first bank BK1 and the second bank BK2, a source conductive film 37 of the same material and layer as the source wiring SH of the thin film transistor layer 4 is formed. Therefore, in the first connecting portion CN1 including the position between the first bank BK1 and the second bank BK2, the conductive film 36 is connected to the source conductive film 37.

[0082] like Figure 3 As shown, the display device 2A includes a terminal portion 38 in the frame area NA. The terminal portion 38 is formed around the second bank BK2. A driver (not shown) is mounted on the terminal portion 38, and the driver supplies a signal for driving each light-emitting element in the display area DA via a routing wiring 39. The slit 35 may not be formed at the position where the routing wiring 39 is formed around the four sides of the display area DA.

[0083] The source conductive film 37 is also formed at a position overlapping the routing wiring 39 and the first bank BK1 and the second bank BK2. Therefore, the routing wiring 39 is connected to the source conductive film 37 in the second connection portion CN2 at a position overlapping the routing wiring 39 and including the first bank BK1 and the second bank BK2.

[0084] The source conductive film 37 in the first connection portion CN1 is electrically connected to the source conductive film 37 in the second connection portion CN2. Therefore, the electrical connection between the high voltage power supply and the trunk wiring 34, and further the high voltage power supply and the auxiliary wiring 26 is established via the routing wiring 39, the source conductive film 37, and the conductive film 36. Therefore, the auxiliary wiring 26 is electrically connected to both the high voltage power supply and the second electrode 28, which has the effect of reducing the voltage drop at a position of the second electrode 28 away from the high voltage power supply.

[0085] In addition, when the support substrate 10 is a flexible substrate, Figure 3 As shown, the display device 2A may also include a bending portion F formed along the outer periphery of the display device 2A between the second bank BK2 and the terminal portion 38. The actual display device 2A is bent by the bending portion F, so that the peripheral side of the display device 2A including the terminal portion 38 is folded from the bending portion F toward the back side of the display device 2A.

[0086] Next, refer to Figure 6 , a method for manufacturing the display device 2A according to this embodiment is described. Figure 6 It is a flowchart showing each manufacturing process of the display device 2A involved in this embodiment.

[0087] First, the resin layer is formed on a light-transmitting support substrate (e.g., a mother glass substrate) (step S1). Next, the barrier layer is formed on the upper layer of the resin layer (step S2). Next, the thin film transistor layer 4 is formed on the upper layer of the barrier layer (step S3). In the formation of each layer from step S1 to step S3, a conventionally known film forming method can be used.

[0088] In addition, in step S3, the source conductive film 37 may be formed together with the source wiring SH. In addition, the slit 35 and a part of the second bank may be formed together with the planarization film 21. Furthermore, the transistor included in the gate driver monolith GD may be formed together with the thin film transistor Tr in the thin film transistor layer 4.

[0089] Next, a light emitting element layer 5 is formed on the upper layer of the thin film transistor layer 4 (step S4). After step S4, a sealing layer 6 is formed (step S5). Next, the laminate including the support substrate 10, the resin layer, the barrier layer, the thin film transistor layer 4, the light emitting element layer 5 and the sealing layer 6 is cut to obtain a plurality of single pieces (step S6). Next, an electronic circuit substrate (e.g., an IC chip) is mounted on the terminal portion 38 as the display device 2A (step S7).

[0090] In addition, in the present embodiment, the light-transmitting glass substrate may be directly used as the support substrate 10. However, the flexible display device 2A can be manufactured by adding some steps.

[0091] For example, after step S5, a laser is irradiated to the lower surface of the resin layer through the light-transmitting support substrate to reduce the bonding force between the support substrate and the resin layer, and the support substrate is peeled off from the resin layer. Next, a lower surface film such as a PET film is attached to the lower surface of the resin layer as the support substrate 10. Then, by transitioning to step S6, the flexible display device 2A can be obtained. In this case, the terminal portion 38 side can also be folded from the bent portion F to the back side of the support substrate 10 between step S6 and step S7.

[0092] [Modification 1]

[0093] Figure 7 It is a side cross-sectional view showing a specific configuration example of a display device 2B according to Modification 1. The same components as those of Embodiment 1 are denoted by the same reference numerals, and detailed description thereof will not be repeated.

[0094] Reference Figure 2 In the above example, the auxiliary wiring 26 is formed on the second electrode 28, but the auxiliary wiring 26 of the display device 2B involved in the modification example 1 may also be as follows. Figure 7 As shown, it is formed on the edge cover 23 so as to be covered by the second electrode 28.

[0095] According to this structure, in Modification 1, the flatness of the upper surface of the second electrode 28 can be improved, and the sealing layer 6 can be formed more easily than in Embodiment 1.

[0096] [Variation 2]

[0097] Figure 8 1 is a side cross-sectional view showing a specific configuration example of a display device 2C according to Modification 2. The same components as those of Embodiment 1 are denoted by the same reference numerals, and detailed description thereof will not be repeated.

[0098] exist Figure 8In the modified examples shown below, the resin layer 12 and the barrier layer 3 are shown in the figure. In addition, the provision of the hole injection layer 41 is omitted.

[0099] The thin film transistor layer 4 includes, from the bottom layer, a semiconductor layer 15, a first inorganic layer 16 (gate insulating film), a gate electrode GE, a second inorganic layer 18, a capacitor wiring CE, a third inorganic layer 20, a source wiring SH (metal wiring layer) and a source electrode SE, and a planarization film 21 (interlayer insulating film). The thin film transistor Tr is configured to include the semiconductor layer 15, the first inorganic layer 16 and the gate electrode GE.

[0100] The semiconductor layer 15 is composed of, for example, low temperature polysilicon (LTPS) or an oxide semiconductor. Figure 8 In the figure, the thin film transistor in which the semiconductor layer 15 serves as a channel is shown as a top gate structure, but it may also be a bottom gate structure (for example, when the channel of the thin film transistor is an oxide semiconductor).

[0101] The gate electrode GE and the capacitor electrode CE include, for example, at least one of aluminum (Al), tungsten (W), molybdenum (Mo), tantalum (Ta), chromium (Cr), titanium (Ti) and copper (Cu). In addition, the gate electrode GE and the capacitor electrode CE are composed of a single layer film or a stacked film of the above metals. In particular, in the present embodiment, the gate electrode GE includes Mo.

[0102] The first inorganic layer 16, the second inorganic layer 18, and the third inorganic layer 20 may be formed of, for example, silicon oxide (SiO x ) film, silicon nitride (SiN x ) film or a laminated film thereof. The planarizing film 21 can be made of a photosensitive organic material that can be coated, such as polyimide, acrylic acid, etc. A contact hole 21c is formed at a position of the planarizing film 21 that overlaps with the source wiring SH of the thin film transistor Tr.

[0103] The sealing layer 6 includes a first inorganic sealing film 31 on top of the second electrode 28, an organic sealing film 32 on top of the first inorganic sealing film 31, and a second inorganic sealing film 33 on top of the organic sealing film 32, to prevent foreign matter such as water and oxygen from penetrating into the light-emitting element layer 5. The first inorganic sealing film 31 and the second inorganic sealing film 33 can be composed of, for example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a laminated film thereof formed by a CVD method. The organic sealing film 32 can be composed of a photosensitive organic material such as polyimide or acrylic acid that can be applied.

[0104] The second electrode 28 is also formed at a position overlapping with the contact hole formed in the electron transport layer 27 , thereby forming a contact portion 28 c and establishing electrical connection between the auxiliary wiring 26 and the second electrode 28 .

[0105] The edge cover 23C may be disposed on the hole transport layer 24C formed on the red, green and blue sub-pixels. The edge cover 23C has an opening 23h corresponding to each of the plurality of light emitting elements, and a portion of the hole transport layer 24C is exposed from the edge cover 23C.

[0106] like Figure 8 As shown, the edge cover 23C of the display device 2C covers the edge of the portion of the hole transport layer 24C corresponding to the red light-emitting layer 25R, exposing the middle of the portion of the hole transport layer 24C corresponding to the red light-emitting layer 25R, covers the edge of the portion of the hole transport layer 24C corresponding to the green light-emitting layer 25G, exposing the middle of the portion of the hole transport layer 24C corresponding to the green light-emitting layer 25G, and covers the edge of the portion of the hole transport layer 24C corresponding to the blue light-emitting layer 25B, exposing the middle of the portion of the hole transport layer 24C corresponding to the blue light-emitting layer 25B.

[0107] [Variation 3]

[0108] Fig. 9 2 is a side cross-sectional view showing a specific configuration example of a display device 2D according to Modification 3. The same components as those of Modification 2 are denoted by the same reference numerals, and detailed description thereof will not be repeated.

[0109] The edge cover 23D of the display device 2D covers the edge of the first electrode 22 and has an opening 23h corresponding to each of the plurality of light emitting elements. A portion of each first electrode 22 is exposed from the edge cover 23D. The hole transport layer 24D is formed to cover the edge cover 23D, the opening 23h and the auxiliary wiring 26.

[0110] The contact hole overlapping with the contact hole formed in the electron transport layer 27 is formed so as to reach the auxiliary wiring 26 also on the hole transport layer 24D. Thus, the contact portion 28c reaches the auxiliary wiring 26, and the electrical connection between the auxiliary wiring 26 and the second electrode 28 is established.

[0111] like Fig. 9 As shown, the edge cover 23D of the display device 2D covers the edge of the first electrode 22 corresponding to the red light emitting layer 25R so that the center of the first electrode 22 is exposed, covers the edge of the first electrode 22 corresponding to the green light emitting layer 25G so that the center of the first electrode 22 is exposed, and covers the edge of the first electrode 22 corresponding to the blue light emitting layer 25B so that the center of the first electrode 22 is exposed. Fig.10 The same is true in .

[0112] [Variation 4]

[0113] Fig.101 is a side cross-sectional view showing a specific configuration example of a display device 2E according to Modification 4. The same components as those of Modification 3 are denoted by the same reference numerals, and detailed description thereof will not be repeated.

[0114] Compared with Modification 3, the auxiliary wiring 26 is formed on the upper surface of the hole transport layer 24D. In this case, the contact hole forming the contact portion 28 c is not formed in the hole transport layer 24D but is formed only in the electron transport layer 27 .

[0115] [Implementation Method 2]

[0116] Fig.11 It is a side cross-sectional view showing a specific configuration example of a display device 2F according to Embodiment 2. The same components as those of Modification 2 are denoted by the same reference numerals, and detailed description thereof will not be repeated.

[0117] Compared with the display device 2C of variant example 2, the display device 2F of embodiment 2 has two different structures in that the film thicknesses of the electron transport layer 27R, the electron transport layer 27G and the electron transport layer 27B are different from each other, and the edge cover 23 covers the edges of the red light-emitting layer 25R, the green light-emitting layer 25G and the blue light-emitting layer 25B.

[0118] The thickness dR of the electron transit layer 27R is 80 nm, the thickness dG of the electron transit layer 27G is 60 nm, and the thickness dB of the electron transit layer 27B is 40 nm. That is, the thickness dR of the electron transit layer 27R is greater than the thickness dG of the electron transit layer 27G, and the thickness dG is greater than the thickness dB of the electron transit layer 27B.

[0119] When the current density of the current flowing through any of the electron transport layers 27R, 27G, and 27B of the light-emitting element of the display device 2F according to the present embodiment is represented by J, the following equation (1) holds true according to Child's law.

[0120] J=9ε r ε0μ e V 2 / 8d 3 ･･･(1)

[0121] Here, ε r μ is the relative dielectric constant of the electron transport layers 27R, 27G, and 27B relative to vacuum, and ε0 is the dielectric constant of vacuum. e is the mobility of electrons in the electron transport layers 27R, 27G, and 27B. V is the voltage applied to the electron transport layers 27R, 27G, and 27B. d is the film thickness of the electron transport layers 27R, 27G, and 27B.

[0122] Therefore, according to the above formula (1), the smaller the film thickness of the electron transport layer 27R, 27G, and 27B, the greater the current density of the current flowing through the electron transport layer 27R, 27G, and 27B. Therefore, by making the film thickness dR greater than the film thickness dG, and making the film thickness dG greater than the film thickness dB, the current density of the current flowing in the electron transport layer 27G and the electron transport layer 27B can be made greater than the current density of the current flowing in the electron transport layer 27R.

[0123] By increasing the current density of the current flowing in the electron transport layer 27R, the density of electrons injected from the electron transport layer 27 to the light emitting layer 25 increases. Therefore, by the above-mentioned configuration, the electron injection efficiency from the electron transport layer 27 to the light emitting layer 25 between the light emitting elements due to the difference in energy level between the electron transport layer 27 and the light emitting layer 25 can be optimized.

[0124] In addition, in this embodiment, the materials of the electron transport layers 27R, 27G, and 27B may be different between the light-emitting elements. In the mutually different electron transport layers 27R, 27G, and 27B, since the film thickness and the material are different, the electron injection efficiency from the electron transport layer 27 to the light-emitting layer 25 between the light-emitting elements can be optimized more efficiently.

[0125] like Fig.11 As shown, the edge cover 23 covers the edge of the red light emitting layer 25R to expose the middle of the red light emitting layer 25R, covers the edge of the green light emitting layer 25G to expose the middle of the green light emitting layer 25G, and covers the edge of the blue light emitting layer 25B to expose the middle of the blue light emitting layer 25B. Fig.12 and Fig.13 The same is true in Chinese.

[0126] [Implementation method 3]

[0127] Fig.12 It is a side cross-sectional view showing a specific configuration example of a display device 2G according to Embodiment 3. The same components as those of Modification 2 are denoted by the same reference numerals, and detailed description thereof will not be repeated.

[0128] A display device 2G according to Embodiment 3 and Figure 8 The display device 2C described above is different in that an electron transport layer 29 is provided instead of the electron transport layer 27 and the second electrode 28, and an edge cover 23 covers the edges of the red light emitting layer 25R, the green light emitting layer 25G, and the blue light emitting layer 25B.

[0129] The electron transport layer 29 is formed for each of the plurality of light-emitting elements at a position overlapping with each of the first electrodes 22, similarly to the electron transport layer 27. In the present embodiment, the electron transport layer 29 includes an electron transport layer 29R for the red light-emitting element 5R, an electron transport layer 29G for the green light-emitting element 5G, and an electron transport layer 29B for the blue light-emitting element 5B.

[0130] The electron transport layer 29 includes both the material of the electron transport layer 27 and the material of the second electrode 28. For example, the electron transport layer 29 includes a photosensitive material and oxide nanoparticles, and metal nanowires (not shown) are dispersed in the photosensitive material. Therefore, the electron transport layer 29 also functions as a counter electrode corresponding to the first electrode 22. In other words, the display device 2G of this embodiment can be regarded as Figure 8 The display device 2C has a structure in which the electron transport layer 27 and the second electrode 28 are formed as the same electron transport layer 29 .

[0131] In addition, in the present embodiment, the auxiliary wiring 26 formed on the edge cover 23 is in direct contact with the electron transport layer 29 having the function of the second electrode. Therefore, it is not necessary to form a contact hole in the electron transport layer 29 for the electrical connection between the auxiliary wiring 26 and the second electrode. Therefore, in the present embodiment, since the contact hole is not formed, the positional accuracy requirement for forming components such as the light emitting layer 25 is reduced, and it is easier to achieve a higher resolution of the display device 2G.

[0132] [Implementation Method 4]

[0133] Fig.13 It is a side cross-sectional view showing a specific configuration example of a display device 2H according to Embodiment 4. The same components as those of Embodiment 3 are denoted by the same reference numerals, and detailed description thereof will not be repeated.

[0134] The display device 2H according to this embodiment is different from the display device 2H according to the previous embodiment. Fig.12 Compared with the display device 2G of FIG. 1 , the configuration is different only in that the auxiliary wiring 26 is formed between the electron transport layer 29 and the first inorganic sealing film 31 and is adjacent to the electron transport layer 29 on the sealing layer 6 side.

[0135] In this embodiment, as in Embodiment 3, there is no need to form a contact hole in the electron transport layer 29 . Therefore, the positional accuracy requirements for forming components such as the light emitting layer 25 can be reduced, and the display device 2H can be more easily improved in resolution.

[0136] Furthermore, in the present embodiment, the auxiliary wiring 26 is formed after the electron transport layer 29 is formed. Therefore, damage to the layers below the electron transport layer 29 in the patterning process of the auxiliary wiring 26 is reduced.

[0137] In addition, since the electron transport layer 29 includes metal nanowires dispersed in the photosensitive resin, the metal nanowires are buried in the electron transport layer 29. Therefore, in the present embodiment, the damage to the metal nanowires in the electron transport layer 29 can be reduced in the patterning process of the auxiliary wiring 26. Therefore, it is not necessary to form a protective film or the like on the electron transport layer 29 for protecting the electron transport layer 29 in order to implement the patterning process of the auxiliary wiring 26.

[0138] The light-emitting element layer 5 of the display devices 2A to 2H of the above-mentioned embodiments is flexible and can be bent. In the above-mentioned embodiments, an example is given in which the light-emitting layer 25 is a quantum dot layer having quantum dots, and the light-emitting element layer 5 has a QLED (Quantum dot Light Emitting Diode: quantum dot light-emitting diode) as an example of a light-emitting element. However, it is not limited to this. For example, the light-emitting layer 25 of the above-mentioned embodiments may also be an organic layer. That is, the light-emitting element layer 5 involved in the above-mentioned embodiments may also have an OLED (Organic Light Emitting Diode: organic light-emitting diode) as a light-emitting element. In this case, the display device involved in each embodiment may also be an organic EL (ElectroLuminescence: electroluminescence) display.

[0139] The present invention 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 means disclosed in different embodiments are also included in the technical scope of the present invention. Moreover, new technical features can be formed by combining the technical methods disclosed in each embodiment.

[0140] Description of Reference Numerals

[0141] 2A Display device

[0142] 4 Thin Film Transistor Layer

[0143] 5 Light-emitting element layer

[0144] 5R Red light emitting element

[0145] 5G Green Light Emitting Components

[0146] 5B blue light emitting element

[0147] 6 Sealing layer

[0148] 10 Support base plate (base plate)

[0149] 221 First Electrode

[0150] 23 Edge cover

[0151] 24 Hole transport layer

[0152] 25 Luminous Layer

[0153] 25R Red light emitting layer

[0154] 25G Green light emitting layer

[0155] 25B Blue light emitting layer

[0156] 26 Auxiliary wiring

[0157] 27R Electron transport layer

[0158] 27G Electron Transport Layer

[0159] 27B Electron transport layer

[0160] 28 Second electrode

[0161] 41 Hole injection layer

[0162] DA display area

[0163] NA border area.

Claims

1. A display device, comprising: a display area having a plurality of pixels; and a frame area around the display area, characterized in that: The display region is provided with a substrate, a thin film transistor layer, a light emitting element layer and a sealing layer in order, the light emitting element layer having a plurality of light emitting elements with different luminous colors, and the sealing layer sealing the light emitting element layer, The light-emitting element includes, in order from the substrate side, a first electrode, a hole transport layer, a light-emitting layer, an electron transport layer, and a second electrode. One of the first electrode and the second electrode is an island-shaped electrode provided for each light-emitting element, and the other of the first electrode and the second electrode is a common electrode shared by a plurality of the light-emitting elements. The electron transport layer comprises oxide nanoparticles, a binder resin and a photopolymerization initiator. The light emitting element comprises: A red light emitting element, wherein the light emitting layer has a red light emitting layer that emits red light; A green light emitting element, wherein the light emitting layer includes a green light emitting layer that emits green light; and The blue light emitting element comprises a blue light emitting layer for emitting blue light in the light emitting layer. Each of the plurality of pixels includes: a red sub-pixel having the red light-emitting element; a green sub-pixel having the green light-emitting element; and a blue sub-pixel having the blue light-emitting element, In the red light-emitting element, the green light-emitting element, and the blue light-emitting element, materials of the electron transport layer are different from each other, The oxide nanoparticles of the electron transport layer of the red light-emitting element are ZnO nanoparticles, The oxide nanoparticles of the electron transport layer of the green light emitting element are MgZnO nanoparticles, The oxide nanoparticles of the electron transport layer of the blue light-emitting element are LiZnO nanoparticles.

2. The display device according to claim 1, characterized in that The film thickness of the electron transport layer of the red light-emitting element, the film thickness of the electron transport layer of the green light-emitting element, and the film thickness of the electron transport layer of the blue light-emitting element are different from each other.

3. The display device according to claim 2, characterized in that: The film thickness of the electron transport layer gradually decreases in the order of the red light-emitting element, the green light-emitting element, and the blue light-emitting element.

4. The display device according to claim 1, characterized in that The light emitting element layer further comprises: an edge mask that divides the pixel into the red sub-pixel, the green sub-pixel, and the blue sub-pixel; and The auxiliary wiring is formed in a lattice shape at a position overlapping with the edge cover, The auxiliary wiring is electrically connected to the second electrode.

5. The display device according to claim 4, characterized in that: The auxiliary wiring is adjacent to the sealing layer side of the edge cover.

6. The display device according to claim 4, characterized in that: The auxiliary wiring is adjacent to the sealing layer side of the second electrode.

7. The display device according to claim 1, characterized in that: The common electrode includes metal nanowires.

8. A display device comprising: a display area having a plurality of pixels; and a frame area around the display area, characterized in that: The display region is provided with a substrate, a thin film transistor layer, a light emitting element layer and a sealing layer in order, the light emitting element layer having a plurality of light emitting elements with different luminous colors, and the sealing layer sealing the light emitting element layer, The light-emitting element includes, in order from the substrate side, a first electrode, a hole transport layer, a light-emitting layer, an electron transport layer, and a second electrode. One of the first electrode and the second electrode is an island-shaped electrode provided for each light-emitting element, and the other of the first electrode and the second electrode is a common electrode shared by a plurality of the light-emitting elements. The electron transport layer comprises oxide nanoparticles, a binder resin and a photopolymerization initiator. The light-emitting elements include: a red light-emitting element having a red light-emitting layer that emits red light; a green light-emitting element having a green light-emitting layer that emits green light; and a blue light-emitting element having a blue light-emitting layer that emits blue light. Each of the plurality of pixels includes: a red sub-pixel having the red light-emitting element; a green sub-pixel having the green light-emitting element; and a blue sub-pixel having the blue light-emitting element, In the red light-emitting element, the green light-emitting element, and the blue light-emitting element, materials of the electron transport layer are different from each other, The oxide nanoparticles of the electron transport layer of the red light emitting element, the green light emitting element and the blue light emitting element are ZnO nanoparticles, The diameter of the ZnO nanoparticles of the electron transport layer of the red light-emitting element is greater than the diameter of the ZnO nanoparticles of the electron transport layer of the green light-emitting element. The diameter of the ZnO nanoparticles of the electron transport layer of the green light emitting element is greater than the diameter of the ZnO nanoparticles of the electron transport layer of the blue light emitting element.

9. The display device according to claim 8, characterized in that: The diameter of the ZnO nanoparticles in the electron transport layer of the red light-emitting element is greater than or equal to 5 nm and less than or equal to 8 nm. The diameter of the ZnO nanoparticles in the electron transport layer of the green light emitting element is greater than or equal to 3 nm and less than or equal to 5 nm. The diameter of the ZnO nanoparticles in the electron transport layer of the blue light-emitting element is greater than or equal to 1.5 nm and less than or equal to 3 nm.

10. The display device according to claim 8, characterized in that: The film thickness of the electron transport layer of the red light-emitting element, the film thickness of the electron transport layer of the green light-emitting element, and the film thickness of the electron transport layer of the blue light-emitting element are different from each other.

11. The display device according to claim 10, characterized in that: The film thickness of the electron transport layer gradually decreases in the order of the red light-emitting element, the green light-emitting element, and the blue light-emitting element.

12. The display device according to claim 8, characterized in that The light emitting element layer further comprises: an edge mask that divides the pixel into the red sub-pixel, the green sub-pixel, and the blue sub-pixel; and The auxiliary wiring is formed in a lattice shape at a position overlapping with the edge cover, The auxiliary wiring is electrically connected to the second electrode.

13. The display device according to claim 12, characterized in that: The auxiliary wiring is adjacent to the sealing layer side of the edge cover.

14. The display device according to claim 12, characterized in that: The auxiliary wiring is adjacent to the sealing layer side of the second electrode.

15. The display device according to claim 8, characterized in that: The common electrode includes metal nanowires.

16. A display device comprising: a display area having a plurality of pixels; and a frame area around the display area, characterized in that: The display region is provided with a substrate, a thin film transistor layer, a light emitting element layer and a sealing layer in order, the light emitting element layer having a plurality of light emitting elements with different luminous colors, and the sealing layer sealing the light emitting element layer, The light-emitting element includes, in order from the substrate side, a first electrode, a hole transport layer, a light-emitting layer, an electron transport layer, and a second electrode. One of the first electrode and the second electrode is an island-shaped electrode provided for each light-emitting element, and the other of the first electrode and the second electrode is a common electrode shared by a plurality of the light-emitting elements. The electron transport layer comprises oxide nanoparticles, a binder resin and a photopolymerization initiator. The light-emitting elements include: a red light-emitting element having a red light-emitting layer that emits red light; a green light-emitting element having a green light-emitting layer that emits green light; and a blue light-emitting element having a blue light-emitting layer that emits blue light. Each of the plurality of pixels includes: a red sub-pixel having the red light-emitting element; a green sub-pixel having the green light-emitting element; and a blue sub-pixel having the blue light-emitting element, In the red light-emitting element, the green light-emitting element, and the blue light-emitting element, materials of the electron transport layer are different from each other, The oxide nanoparticles of the electron transport layer of the red light-emitting element are Mg xr Zn (1-xr) O nanoparticles, The oxide nanoparticles of the electron transport layer of the green light emitting element are Mg xg Zn (1-xg) O nanoparticles, The oxide nanoparticles of the electron transport layer of the blue light-emitting element are Mg xb Zn (1-xb) O nanoparticles, xr, xg, and xb are real numbers greater than or equal to 0 and less than 1, xr <xg<xb。 17. The display device according to claim 16, characterized in that: The film thickness of the electron transport layer of the red light-emitting element, the film thickness of the electron transport layer of the green light-emitting element, and the film thickness of the electron transport layer of the blue light-emitting element are different from each other.

18. The display device according to claim 17, characterized in that: The film thickness of the electron transport layer gradually decreases in the order of the red light-emitting element, the green light-emitting element, and the blue light-emitting element.

19. The display device according to claim 16, characterized in that: The light emitting element layer further comprises: an edge mask that divides the pixel into the red sub-pixel, the green sub-pixel, and the blue sub-pixel; and The auxiliary wiring is formed in a lattice shape at a position overlapping with the edge cover, The auxiliary wiring is electrically connected to the second electrode.

20. The display device according to claim 19, characterized in that The auxiliary wiring is adjacent to the sealing layer side of the edge cover.

21. The display device according to claim 19, characterized in that The auxiliary wiring is adjacent to the sealing layer side of the second electrode.

22. The display device according to claim 16, characterized in that The common electrode includes metal nanowires.

Images