Display device

Abstract

The present invention comprises: a base substrate (10); a TFT layer (20) which is provided on the base substrate (10); a light-emitting element layer (40a) which is provided on the TFT layer (20), and in which a plurality of first electrodes (30), a common edge cover (31a), a plurality of light-emitting functional layers (32), and a common second electrode (33) are laminated in this order in correspondence with a plurality of subpixels that constitute a display region (D); and a sealing film (45) which is provided on the light-emitting element layer (40a), wherein a light-shielding layer (44a) that is formed from a black resin so as to overlap with the edge cover (31a) is provided to a first inorganic sealing film (41) that constitutes the sealing film (45), on the opposite side from the base substrate (10).

Description

display device

[0001] This invention relates to a display device.

[0002] In recent years, self-emissive display devices using, for example, organic light-emitting diodes (OLEDs) and quantum dot light-emitting diodes (QLEDs) have attracted attention as alternatives to liquid crystal displays. Here, a display device using QLEDs comprises, for example, a base substrate, a thin-film transistor (TFT) layer provided on the base substrate, a QLED element layer provided on the TFT layer, and a sealing film provided on the QLED element layer. In the QLED element layer, multiple first electrodes, a common edge cover, multiple QLED layers (light-emitting functional layers), and a common second electrode are stacked in order, corresponding to multiple subpixels that constitute the display area.

[0003] For example, Patent Document 1 discloses an organic electroluminescent (EL) device having a substrate, pixel electrodes (corresponding to the first electrode) provided on the substrate for each subpixel, a functional layer provided on the pixel electrodes, a counter electrode (corresponding to the second electrode) provided on the functional layer, and a sealing film provided on the counter electrodes, wherein a light-shielding layer is provided between the pixel electrodes on the upper layer of the sealing layer to suppress the generation of crosstalk (stray light).

[0004] Japanese Patent Publication No. 2016-143630

[0005] Incidentally, in self-emissive display devices using QLEDs, OLEDs, etc., edge covers are provided in a grid pattern to cover the peripheral edges of each first electrode, and by forming these edge covers from black resin, the reflection of ambient light is suppressed, and a display device that does not use polarizing plates has been proposed. Furthermore, in such self-emissive display devices, it has been proposed to form the light-emitting functional layer, which is formed by the conventional vacuum deposition method, by a coating method such as inkjet. Therefore, in a self-emissive display device in which the edge cover is formed from black resin and the light-emitting functional layer is formed by a coating method, if the film thickness of the edge cover is increased to improve the reflection suppression performance, the film thickness of the light-emitting functional layer covering the edge cover becomes uneven, resulting in uneven coating. Conversely, if the film thickness of the edge cover is reduced to suppress the occurrence of uneven coating of the light-emitting functional layer, the reflection suppression performance becomes insufficient, so there is a trade-off between ensuring reflection suppression performance and ensuring the coatability of the light-emitting functional layer. It should be noted that in the organic EL device disclosed in the above-mentioned Patent Document 1, the light-shielding layer is a graphene laminate film, so there is room for improvement in the manufacturing process.

[0006] The present invention has been made in view of the above, and its objective is to ensure the coating properties of the light-emitting functional layer while ensuring reflection suppression performance using a black resin.

[0007] To achieve the above objective, the present invention provides a display device comprising: a base substrate; a thin film transistor layer provided on the base substrate; a light-emitting layer provided on the thin film transistor layer, wherein a plurality of first electrodes, a common edge cover, a plurality of light-emitting functional layers, and a common second electrode are sequentially laminated corresponding to a plurality of subpixels constituting a display area; and a sealing film provided on the light-emitting layer, wherein a first inorganic sealing film, an organic sealing film, and a second inorganic sealing film are sequentially laminated, wherein the edge cover is provided so as to cover the peripheral end of each of the plurality of first electrodes, and a light-shielding layer made of black resin is provided on the side of the first inorganic sealing film opposite to the base substrate so as to overlap with the edge cover.

[0008] According to the present invention, by using a black resin, it is possible to ensure the coating properties of the light-emitting functional layer while maintaining reflection suppression performance.

[0009] Figure 1 is a plan view showing the schematic configuration of a QLED display device according to the first embodiment of the present invention. Figure 2 is a plan view of the display area of ​​a QLED display device according to the first embodiment of the present invention. Figure 3 is a cross-sectional view of the display area of ​​a QLED display device according to the first embodiment of the present invention. Figure 4 is an equivalent circuit diagram of the TFT layer constituting the QLED display device according to the first embodiment of the present invention. Figure 5 is a cross-sectional view of the QLED layer constituting the QLED display device according to the first embodiment of the present invention. Figure 6 is a detailed cross-sectional view of the display area of ​​a QLED display device according to the first embodiment of the present invention. Figure 7 is another detailed cross-sectional view of the display area of ​​a QLED display device according to the first embodiment of the present invention. Figure 8 is a cross-sectional view of the display area of ​​a QLED display device according to the second embodiment of the present invention, and corresponds to Figure 6. Figure 9 is a cross-sectional view of the display area of ​​a QLED display device according to the third embodiment of the present invention, and corresponds to Figure 6. Figure 10 is a cross-sectional view of the display area of ​​a QLED display device according to the fourth embodiment of the present invention, and corresponds to Figure 6.

[0010] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments.

[0011] 《First Embodiment》 Figures 1 to 7 show a first embodiment of the display device according to the present invention. In the following embodiments, a QLED display device equipped with a QLED element layer is exemplified as a display device equipped with a light-emitting element layer. Here, Figure 1 is a plan view showing the schematic configuration of the QLED display device 50a of this embodiment. Figures 2 and 3 are a plan view and a cross-sectional view of the display area D of the QLED display device 50a. Figure 4 is an equivalent circuit diagram of the TFT layer 20 constituting the QLED display device 50a. Figure 5 is a cross-sectional view of the QLED layer 32 constituting the QLED display device 50a. Figure 6 is a detailed cross-sectional view of the display area D of the QLED display device 50a along the Y direction in Figure 2. Figure 7 is a detailed cross-sectional view of the display area D of the QLED display device 50a along the X direction in Figure 2.

[0012] As shown in Figure 1, the QLED display device 50a includes, for example, a rectangular display area D for displaying images and a frame-shaped frame area F surrounding the display area D. In this embodiment, a rectangular display area D is used as an example, but this rectangular shape also includes substantially rectangular shapes such as shapes with arc-shaped sides, shapes with arc-shaped corners, and shapes with notches in part of the sides.

[0013] In the display area D, as shown in Figure 2, multiple subpixels P are arranged in a matrix. Also, in the display area D, as shown in Figure 2, for example, subpixels Pr having a red light-emitting region Lr for displaying red, subpixels Pg having a green light-emitting region Lg for displaying green, and subpixels Pb having a blue light-emitting region Lb for displaying blue are arranged adjacent to each other. In the display area D, for example, one pixel is composed of three adjacent subpixels Pr, Pg, and Pb, each having a red light-emitting region Lr, a green light-emitting region Lg, and a blue light-emitting region Lb, respectively, and displaying different colors.

[0014] A terminal portion T is provided at the positive end of the frame region F in the Y direction in Figure 1, extending in one direction (the X direction in Figure 1). Furthermore, between the display region D and the terminal portion T, as shown in Figure 1, a bendable portion B is provided on the display region D side of the terminal portion T in the frame region F, extending in one direction (the X direction in the figure), which can be bent, for example, 180° (in a U shape) with the X direction in the figure as the axis of bending.

[0015] As shown in Figure 3, the QLED display device 50a comprises a resin substrate 10 provided as a base substrate, a TFT layer 20 provided on the resin substrate 10, a QLED element layer 40a provided on the TFT layer 20 as a light-emitting layer, and a sealing film 45a provided on the QLED element layer 40a.

[0016] The resin substrate 10 is made of, for example, polyimide resin.

[0017] As shown in Figure 3, the TFT layer 20 comprises a base coat film 11 provided on a resin substrate 10, a plurality of first TFTs 9a, a plurality of second TFTs 9b, and a plurality of capacitors 9c provided on the base coat film 11, and a planarization film 19 provided on each of the first TFTs 9a, second TFTs 9b, and capacitors 9c. In the TFT layer 20, as shown in Figure 2, a plurality of gate lines 14g are provided so as to extend parallel to each other in the X direction in the figure. Also in the TFT layer 20, as shown in Figure 2, a plurality of source lines 18f are provided so as to extend parallel to each other in a direction that intersects (orthogonal to) the plurality of gate lines 14g, i.e., in the Y direction in the figure. In the TFT layer 30, as shown in Figure 2, a plurality of power lines 18g are provided so as to extend parallel to each other in the Y direction in the figure. And each power line 18g is provided so as to be adjacent to each source line 18f, as shown in Figure 2. Furthermore, in the TFT layer 20, as shown in Figure 4, a first TFT 9a, a second TFT 9b, and a capacitor 9c are provided in each subpixel P. In the TFT layer 20, as shown in Figure 3, a base coat film 11, a semiconductor film which will become a semiconductor layer 12a (described later), a first metal film which will become a gate insulating film 13, a gate line 14g, a first interlayer insulating film 15, a second metal film which will become an upper conductive layer 16c (described later), a second interlayer insulating film 17, a third metal film which will become a source line 18f or power line 18g, and a planarization film 19 are stacked in that order on the resin substrate 10.

[0018] The base coat film 11, gate insulating film 13, first interlayer insulating film 15, and second interlayer insulating film 17 are composed of, for example, single-layer or multilayer films of inorganic insulating films such as silicon nitride, silicon oxide, or silicon oxynitride.

[0019] As shown in Figure 4, the first TFT 9a is electrically connected to the corresponding gate line 14g, source line 18f, and second TFT 9b at each subpixel P. Here, as shown in Figure 3, the first TFT 9a comprises a semiconductor layer 12a provided on a base coat film 11, a gate electrode 14a provided on the semiconductor layer 12a via a gate insulating film 13, and a source electrode 18a and a drain electrode 18b provided spaced apart from each other on the second interlayer insulating film 17.

[0020] The semiconductor layer 12a and the semiconductor layer 12b, described later, are formed from a semiconductor film made of polysilicon such as LTPS (low temperature polysilicon), and include a source region and a drain region defined to be spaced apart from each other, and a channel region defined between the source region and the drain region.

[0021] The gate electrode 14a is provided so as to overlap the channel region of the semiconductor layer 12a and is configured to control conductivity between the source region and the drain region of the semiconductor layer 12a. Here, the gate electrode 14a is formed of a first metal film, similar to the gate wire 14g, etc.

[0022] As shown in Figure 3, the source electrode 18a and the drain electrode 18b are electrically connected to the source region and drain region of the semiconductor layer 12a, respectively, via contact holes formed in the gate insulating film 13, the first interlayer insulating film 15, and the second interlayer insulating film 17. Here, the source electrode 18a and the drain electrode 18b are formed from a third metal film, similar to the source wire 18f and the power supply wire 18g.

[0023] As shown in Figure 4, the second TFT 9b is electrically connected to the corresponding first TFT 9a, power line 18g, and QLED element 35 (described later) at each subpixel P. Here, as shown in Figure 3, the second TFT 9b comprises a semiconductor layer 12b provided on the base coat film 11, a gate electrode 14b provided on the semiconductor layer 12b via a gate insulating film 13, and a source electrode 18c and a drain electrode 18d provided spaced apart from each other on the second interlayer insulating film 17.

[0024] The gate electrode 14b is provided so as to overlap the channel region of the semiconductor layer 12b and is configured to control conductivity between the source region and the drain region of the semiconductor layer 12b. Here, the gate electrode 14b is formed of a first metal film, similar to the gate wire 14g, etc.

[0025] As shown in Figure 3, the source electrode 18c and drain electrode 18d are electrically connected to the source region and drain region of the semiconductor layer 12b, respectively, through contact holes formed in the laminated film of the gate insulating film 13, the first interlayer insulating film 15, and the second interlayer insulating film 17. Here, the source electrode 18c and drain electrode 18d are formed from a third metal film, similar to the source wire 18f and power supply wire 18g.

[0026] In this embodiment, semiconductor layers 12a and 12b formed from a semiconductor film made of polysilicon are exemplified, but semiconductor layers 12a and 12b may be formed from a semiconductor film made of an oxide semiconductor such as In-Ga-Zn-O. Furthermore, the TFT layer 20 may have a hybrid structure in which a TFT having a semiconductor layer made of polysilicon and a TFT having a semiconductor layer made of an oxide semiconductor are provided.

[0027] As shown in Figure 4, the capacitor 9c is electrically connected to the corresponding first TFT 9a and power line 18g at each sub-pixel P. Here, as shown in Figure 3, the capacitor 9c comprises a lower conductive layer 14c formed of a first metal film, an upper conductive layer 16c formed of a second metal film, and a first interlayer insulating film 15 provided between the lower conductive layer 14c and the upper conductive layer 16c. The upper conductive layer 16c is electrically connected to the power line 18g via a contact hole formed in the second interlayer insulating film 17, as shown in Figure 3.

[0028] The planarized film 19 has a flat surface in the display area D and is made of an organic resin material such as polyimide resin.

[0029] As shown in Figures 3, 6, and 7, the QLED element layer 40a comprises a plurality of first electrodes 30 stacked sequentially corresponding to a plurality of subpixels P, a common edge cover 31a, a plurality of QLED layers 32, and a common second electrode 33. Here, in each subpixel P, the first electrode 30, the QLED layer 32, and the second electrode 33 constitute a QLED element 35, as shown in Figure 3, and in the QLED element layer 40a, the plurality of QLED elements 35 corresponding to the plurality of subpixels P are arranged in a matrix.

[0030] As shown in Figure 3, the first electrode 30 is electrically connected to the drain electrode 18d of the second TFT 9b of each subpixel P via a contact hole formed in the planarization film 19. The first electrode 30 also has the function of injecting holes into the QLED layer 32. Furthermore, to improve the hole injection efficiency into the QLED layer 32, it is more preferable to form the first electrode 30 from a material with a large work function. Here, the first electrode 30 is formed from a laminated film in which transparent conductive films such as an indium tin oxide (ITO) film or an indium zinc oxide (IZO) film, a metal film such as a silver film or a silver alloy film, and transparent conductive films such as an ITO film or an IZO film are sequentially stacked and have light reflectivity.

[0031] The edge cover 31a is provided in a grid pattern across the entire display area D, and as shown in Figure 3, it is provided to cover the peripheral edge of the first electrode 30. Here, the edge cover 31a is composed of a single layer or multilayer film of a transparent inorganic insulating film such as silicon nitride, silicon oxide, or silicon oxynitride.

[0032] The QLED layer 32 is provided as a light-emitting functional layer and, as shown in Figures 5 and 7, comprises a hole injection layer 1, a hole transport layer 2, a light-emitting layer 3, an electron transport layer 4, and an electron injection layer 5 stacked in order on the first electrode 30. In this embodiment, a configuration in which each of the multiple light-emitting functional layers is a QLED layer 32 is illustrated, but at least one of the multiple light-emitting functional layers may be a QLED layer 32.

[0033] The hole injection layer 1, also called the anode buffer layer, has the function of bringing the energy levels of the first electrode 30 and the QLED layer 32 closer together, thereby improving the hole injection efficiency from the first electrode 30 to the QLED layer 32. Examples of materials constituting the hole injection layer 1 include, as organic materials, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, phenylenediamine derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, etc., and as inorganic materials, it contains at least one nanoparticle. The nanoparticle may, for example, contain nickel oxide (NiO) and further contain nitrate ions (NO₂). ３ － ) is included. Furthermore, as shown in Figure 7, the hole injection layer 1 is provided in common to correspond to multiple subpixels P. In this embodiment, a hole injection layer 1 common to multiple subpixels P is illustrated, but multiple hole injection layers 1 may be provided to correspond to multiple subpixels P.

[0034] The hole transport layer 2 has the function of improving the efficiency of hole transport from the first electrode 30 to the QLED layer 32. Examples of materials constituting the hole transport layer 2 include porphyrin derivatives, aromatic tertiary amine compounds, styrylamine derivatives, polyvinylcarbazole, poly-p-phenylenevinylene, polysilane, triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amine-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, hydrogenated amorphous silicon, hydrogenated amorphous silicon carbide, zinc sulfide, zinc selenide, and the like. Furthermore, examples of materials that constitute the hole transport layer 2 include functional polymer materials such as poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl))diphenylamine)] (abbreviated as "TFB"), poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine] (abbreviated as "poly-TPD"), and polyvinylcarbazole (abbreviated as "PVK"). The material that constitutes the hole transport layer 2 may consist of only one of the above-mentioned materials, or may consist of two or more as appropriate. In addition, as shown in Figure 7, multiple hole transport layers 2 are provided corresponding to multiple subpixels P. Furthermore, as shown in Figure 7, the hole transport layer 2 has a thickness where the subpixel Pg that displays green is thinner than the subpixel Pr that displays red, and a thickness where the subpixel Pb that displays blue is thicker. Therefore, by setting the optical path length according to the wavelengths of red, green, and blue, a cavity structure can be formed that improves the light extraction efficiency through the resonance effect of light.

[0035] The light-emitting layer 3 is a region in which holes and electrons are injected from the first electrode 30 and the second electrode 33, respectively, when voltage is applied by the first electrode 30 and the second electrode 33, and where holes and electrons recombine. Furthermore, as shown in Figure 7, the light-emitting layer 3 includes a red light-emitting layer 3r provided on the sub-pixel Pr that displays red, a green light-emitting layer 3g provided on the sub-pixel Pg that displays green, and a blue light-emitting layer 3b provided on the sub-pixel Pb that displays blue. Here, the light-emitting layer 3 is formed of a material with high luminescence efficiency. The light-emitting layer 3 includes, for example, a plurality of quantum dots as the light-emitting material. Furthermore, each quantum dot constituting the light-emitting layer 3 may have a core / shell structure including a core that emits light when excitons are applied and a shell formed around the core to protect the core. In this embodiment, the light-emitting layer 3 may also include an organic or inorganic ligand that coordinates to each quantum dot by forming a coordination bond with the outermost surface of each quantum dot.

[0036] In this embodiment, "quantum dot" refers to a dot with a maximum width of 100 nm or less. The shape of the quantum dot is not particularly restricted and is not limited to a spherical three-dimensional shape (circular cross-sectional shape), as long as it satisfies the above maximum width. Furthermore, the shape of the quantum dot may be, for example, a polygonal cross-sectional shape, a rod-shaped three-dimensional shape, a branch-shaped three-dimensional shape, a three-dimensional shape with irregularities on the surface, or a combination thereof.

[0037] Quantum dots are typically preferably made of a semiconductor. Here, the semiconductor preferably has a certain bandgap. Also, the semiconductor may be any material that can emit light and preferably contains at least the materials described below. Further, the semiconductor preferably can emit blue, green, and red light respectively. Also, the semiconductor contains at least one selected from the group consisting of, for example, II-VI group compounds, III-V group compounds, chalcogenides, and perovskite compounds. Note that the II-VI group compound means a compound containing a group II element and a group VI element, and the III-V group compound means a compound containing a group III element and a group V element. Also, the group II elements include group-2 elements and group-12 elements, the group III elements include group-3 elements and group-13 elements, the group V elements include group-5 elements and group-15 elements, and the group VI elements may include group-6 elements and group-16 elements.

[0038] The II-VI group compound contains at least one selected from the group consisting of, for example, MgS, MgSe, MgTe, CaS, CaSe, CaTe, SrS, SrSe, SrTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, HgS, HgSe, and HgTe.

[0039] The III-V group compound contains at least one selected from the group consisting of, for example, GaAs, GaP, InN, InAs, InP, and InSb.

[0040] The chalcogenide is a compound containing a group VIA (16) element and contains, for example, CdS or CdSe. Also, the chalcogenide may contain mixed crystals thereof.

[0041] The perovskite compound has a composition represented by, for example, the general formula CsPbX ３ and contains at least one selected from the group consisting of, for example, Cl, Br, and I as the constituent element X.

[0042] Note that the notation of the group number of elements using Roman numerals is based on the old IUPAC (International Union of Pure and Applied Chemistry) system or the old CAS (Chemical Abstracts Service) system, and the notation of the group number of elements using Arabic numerals is based on the current IUPAC system.

[0043] The electron transport layer 4 has a function of efficiently moving electrons to the light-emitting layer 3. Here, examples of the material constituting the electron transport layer 4 include, as organic compounds, oxadiazole derivatives, triazole derivatives, benzoquinone derivatives, naphthoquinone derivatives, anthraquinone derivatives, tetracyanoanthraquinodimethane derivatives, diphenoquinone derivatives, fluorenone derivatives, silole derivatives, metal oxynoid compounds, etc., and inorganic materials can be used. Further, the material constituting the electron transport layer 4 may contain zinc oxide (ZnO), magnesium zinc oxide (MgZnO), etc. Furthermore, the material constituting the electron transport layer 4 may contain only one type of the above-described materials, or may contain two or more types as appropriate. Also, as shown in FIG. 7, the electron transport layer 4 is provided in common corresponding to a plurality of sub-pixels P. In the present embodiment, the electron transport layer 4 common to a plurality of sub-pixels P is exemplified, but a plurality of electron transport layers 4 may be provided corresponding to a plurality of sub-pixels P.

[0044] The electron injection layer 5 has a function of bringing the energy levels of the second electrode 33 and the QLED layer 32 closer and improving the efficiency of injecting electrons from the second electrode 33 into the QLED layer 32. By this function, the driving voltage of the QLED element 35 can be lowered. Note that the electron injection layer 5 is also called a cathode buffer layer. Here, examples of the material constituting the electron injection layer 5 include, for example, inorganic alkali compounds such as lithium fluoride (LiF), magnesium fluoride (MgF ２ ), calcium fluoride (CaF ２ ), strontium fluoride (SrF ２ ), barium fluoride (BaF ２ ), and aluminum oxide (Al ２ O ３Examples include strontium oxide (SrO) and others. Furthermore, as shown in Figure 7, the electron injection layer 5 is provided in common for multiple subpixels P. In this embodiment, a common electron injection layer 5 for multiple subpixels P is illustrated, but multiple electron injection layers 5 may be provided for multiple subpixels P.

[0045] As shown in Figures 3, 6, and 7, the second electrode 33 is provided so as to cover each QLED layer 32 and edge cover 31a. The second electrode 33 also has the function of injecting electrons into the QLED layer 32. Furthermore, in order to improve the electron injection efficiency into the QLED layer 32, it is more preferable that the second electrode 33 be made of a material with a small work function. Here, the second electrode 33 is formed of a transparent conductive film such as an ITO film or an IZO film, and has high light transmittance.

[0046] As shown in Figures 3, 6, and 7, the sealing film 45a is provided so as to cover the second electrode 33 and comprises a first inorganic sealing film 41, an organic sealing film 42, and a second inorganic sealing film 43 that are sequentially laminated on the second electrode 33, and has the function of protecting the QLED layer 32 of the QLED element 35 from moisture, oxygen, etc. Here, the first inorganic sealing film 41 and the second inorganic sealing film 43 are made of inorganic insulating films such as silicon nitride film, silicon oxide film, and silicon oxynitride film. The organic sealing film 42 is made of organic resin material such as acrylic resin, epoxy resin, silicone resin, polyurea resin, parylene resin, polyimide resin, and polyamide resin. Furthermore, in the sealing film 45a, as shown in Figures 3, 6, and 7, a light-shielding layer 44a is provided in a grid pattern on the side of the first inorganic sealing film 41 opposite to the resin substrate 10, specifically between the first inorganic sealing film 41 and the organic sealing film 42, so as to overlap with the edge cover 31a.

[0047] The light-shielding layer 44a is made of a black resin, and is composed of an organic resin material such as acrylic resin, epoxy resin, silicone resin, polyurea resin, parylene resin, polyimide resin, or polyamide resin in which a black pigment such as carbon black is dispersed. Here, the OD (Optical Density) value of the light-shielding layer 44a is, for example, 0.6 or more. The OD value is defined as OD value = -log(emission intensity / incident intensity), and the larger the OD value, the lower the transmittance.

[0048] The QLED display device 50a described above is configured such that, at each subpixel P, a gate signal is input to the first TFT 9a via the gate line 14g, thereby turning on the first TFT 9a, and a voltage corresponding to the source signal is written to the gate electrode 14b and capacitor 9c of the second TFT 9b via the source line 18f. A current from the power line 18g, defined based on the gate voltage of the second TFT 9b, is supplied to the QLED element 35, causing the light-emitting layer 3 of the QLED element 35 to emit light and display an image. In addition, in the QLED display device 50a, even if the first TFT 9a is turned off, the gate voltage of the second TFT 9b is maintained by the capacitor 9c, so the light emission from the light-emitting layer 3 is maintained until the gate signal for the next frame is input.

[0049] Next, the manufacturing method of the QLED display device 50a of this embodiment will be described. The manufacturing method of the QLED display device 50a of this embodiment comprises a TFT layer formation step, a QLED element layer formation step, and a sealing film formation step.

[0050] <TFT layer formation process> First, for example, a non-photosensitive polyimide resin (about 6 μm thick) is applied to a glass substrate, and then a resin substrate 10 is formed by performing pre-baking and post-baking on the applied film.

[0051] Next, a base coat film 11 is formed on the substrate surface on which the resin substrate 10 is formed by sequentially depositing a silicon oxide film (approximately 500 nm thick) and a silicon nitride film (approximately 100 nm thick) using, for example, a plasma CVD (chemical vapor deposition) method.

[0052] Subsequently, an amorphous silicon film (approximately 50 nm thick) is deposited on the substrate surface on which the base coat film 11 is formed by plasma CVD, and the amorphous silicon film is crystallized by laser annealing or the like to form a polysilicon semiconductor film. After that, the semiconductor film is patterned to form semiconductor layers 12a and 12b, etc.

[0053] Furthermore, a silicon oxide film (approximately 100 nm) is formed on the substrate surface on which the semiconductor layer 12a is formed, for example, by plasma CVD, to form a gate insulating film 13 that covers the semiconductor layer 12a.

[0054] Next, a first metal film, such as a molybdenum film (approximately 250 nm thick), is formed on the substrate surface on which the gate insulating film 13 is formed, for example, by sputtering. Then, the first metal film is patterned to form the gate wire 14g, gate electrodes 14a and 14b, lower conductive layer 14c, etc.

[0055] Subsequently, using gate electrodes 14a and 14b as masks, impurity ions are doped to make a portion of the semiconductor layers 12a and 12b conductive.

[0056] Furthermore, a first interlayer insulating film 15 is formed on the substrate surface, where a portion of the semiconductor layer 12a or the like is made conductive, by depositing a silicon nitride film (approximately 100 nm thick) using, for example, a plasma CVD method.

[0057] Next, a second metal film, such as a molybdenum film (approximately 250 nm thick), is deposited on the substrate surface on which the first interlayer insulating film 15 is formed, for example, by sputtering. After that, the second metal film is patterned to form an upper conductive layer 16c, etc.

[0058] Subsequently, a second interlayer insulating film 17 is formed on the substrate surface on which the upper conductive layer 16c etc. is formed, by sequentially depositing a silicon oxide film (approximately 300 nm thick) and a silicon nitride film (approximately 200 nm thick) using, for example, a plasma CVD method.

[0059] Furthermore, contact holes are formed by appropriately patterning the gate insulating film 13, the first interlayer insulating film 15, and the second interlayer insulating film 17.

[0060] Next, a third metal film is formed on the substrate surface where the contact holes are formed, for example by sputtering, by sequentially depositing a titanium film (approximately 50 nm thick), an aluminum film (approximately 600 nm thick), and a titanium film (approximately 50 nm thick). After that, the third metal film is patterned to form source electrodes 18a and 18c, drain electrodes 18b and 18d, source wire 18f, power line 18g, etc.

[0061] Finally, a photosensitive polyimide resin (approximately 2.5 μm thick) is applied to the substrate surface on which the source electrode 18a, etc., is formed, for example, by a spin coating method or a slit coating method. Then, a planarization film 19 is formed by pre-baking, exposure, development, and post-baking of the coated film.

[0062] In this manner, the TFT layer 20 can be formed.

[0063] <QLED element layer formation process> First, on the substrate surface on which the TFT layer 20 was formed in the TFT layer formation process described above, a transparent conductive film such as an ITO film (thickness about 10 nm), a metal film such as an Ag film (thickness about 100 nm), and a transparent conductive film such as an ITO film (thickness about 10 nm) are sequentially formed by, for example, a sputtering method. Then, these laminated films are patterned to form the first electrode 30, etc.

[0064] Next, an inorganic insulating film, such as a silicon nitride film (approximately 300 nm thick), is deposited on the substrate surface on which the first electrode 30 and the like are formed, for example, by plasma CVD. The inorganic insulating film is then patterned to form an edge cover 31a.

[0065] Subsequently, a hole injection layer 1 is formed on the substrate surface on which the edge cover 31a is formed by ejecting an ink containing nanoparticles in which the above-mentioned constituent materials have been dissolved (dispersed), for example, by an inkjet method.

[0066] Furthermore, after forming a resist pattern on the substrate surface on which the hole injection layer 1 is formed, for example, an ink containing nanoparticles in which the constituent materials of the hole transport layer 2 described above are dissolved (dispersed) is ejected by an inkjet method, and then an ink containing nanoparticles in which the constituent materials of the red light-emitting layer (3r) are dissolved (dispersed) is ejected to form the red light-emitting layer (3r) and the hole transport layer 2 of the subpixel Pr by a lift-off method.

[0067] Subsequently, similar to the subpixel Pr, the green light-emitting layer (3g) and hole transport layer 2 for subpixel Pg and Pb, and the blue light-emitting layer (3b) and hole transport layer 2 for subpixel Pb are sequentially formed using the lift-off method. This creates a hole transport layer 2 with different film thicknesses for each subpixel Pr, Pg, and Pb, as well as a light-emitting layer 3 consisting of a red light-emitting layer (3r), a green light-emitting layer (3g), and a blue light-emitting layer (3b).

[0068] Next, an electron transport layer 4 is formed on the substrate surface on which the light-emitting layer 3 is formed by ejecting an ink containing nanoparticles in which the above-mentioned constituent materials are dissolved (dispersed), for example, by an inkjet method.

[0069] Furthermore, the QLED layer 32 is formed by ejecting an ink containing nanoparticles in which the above-mentioned constituent materials are dissolved (dispersed) onto the substrate surface on which the electron transport layer 4 is formed, for example by an inkjet method, to form an electron injection layer 5.

[0070] Finally, a transparent conductive film, such as an ITO film (approximately 100 nm thick), is deposited on the substrate surface on which the QLED layer 32 is formed by sputtering using a mask to form the second electrode 33.

[0071] In this manner, the QLED element layer 40a can be formed.

[0072] <Encapsulation Film Formation Process> First, on the substrate surface on which the QLED element layer 40a was formed in the above QLED element layer formation process, a silicon nitride film (approximately 50 nm), a silicon oxynitride film (approximately 1500 nm), and a silicon oxide film (approximately 50 nm) are sequentially deposited using a film deposition mask, for example, by plasma CVD, to form a first inorganic encapsulation film 41.

[0073] Next, a photosensitive acrylic resin (approximately 2 μm thick) colored black is applied to the substrate surface on which the first inorganic encapsulation film 41 is formed, for example, by a spin coating method or a slit coating method. Then, a light-shielding layer 44a is formed by pre-baking, exposure, development, and post-baking of the coated film.

[0074] Subsequently, an acrylic resin (approximately 10 μm thick) or the like is applied to the substrate surface on which the light-shielding layer 44a is formed, for example, by an inkjet method, to form an organic encapsulation film 42.

[0075] Furthermore, a second inorganic encapsulation film 43 is formed on the substrate surface on which the organic encapsulation film 42 is formed by depositing a silicon nitride film (approximately 500 nm thick) or the like using a film-forming mask, for example, by plasma CVD, thereby forming an encapsulation film 45a.

[0076] Finally, after attaching a protective sheet (not shown) to the substrate surface on which the sealing film 45a is formed, the glass substrate is peeled off from the bottom surface of the resin substrate 10 by irradiating the resin substrate 10 with laser light from the glass substrate side, and then a protective sheet (not shown) is attached to the bottom surface of the resin substrate 10 from which the glass substrate has been peeled off.

[0077] As described above, the QLED display device 50a of this embodiment can be manufactured.

[0078] As described above, in the QLED display device 50a of this embodiment, a light-shielding layer 44a made of black resin is provided between the first inorganic encapsulation film 41 and the organic encapsulation film 42 that constitute the encapsulation film 45a so as to overlap with the edge cover 31a. Therefore, the light-shielding layer 44a suppresses the reflection of external light due to wiring etc. of the TFT layer 20, and reflection suppression performance can be ensured. Furthermore, even if the film thickness of the light-shielding layer 44a made of black resin is increased, it does not significantly affect the coatability of the QLED layer 32 on the resin substrate 10 side, so the coatability of the QLED layer 32 can be ensured. Thus, by using black resin, reflection suppression performance can be ensured and the coatability of the QLED layer 32 can be ensured. In addition, since the light-shielding layer 44a is formed in the encapsulation film 45a and not in the QLED element layer 40a, it is not necessary to consider the effect of degassing from the light-shielding layer 44a, and a lower-cost acrylic resin, for example, can be used instead of polyimide resin, thus reducing manufacturing costs.

[0079] 《Second Embodiment》 Figure 8 shows a second embodiment of the display device according to the present invention. Here, Figure 8 is a cross-sectional view of the display area D of the QLED display device 50b of this embodiment, and corresponds to Figure 6. In the following embodiments, the same reference numerals are used for parts that are the same as in Figures 1 to 7, and their detailed descriptions are omitted.

[0080] In the first embodiment described above, a QLED display device 50a in which the edge cover 31a is formed of an inorganic insulating film was exemplified. However, in this embodiment, a QLED display device 50b in which the edge cover 31b is formed of black resin is exemplified.

[0081] The QLED display device 50b, like the QLED display device 50a of the first embodiment described above, includes a rectangular display area D and a frame-shaped frame area F surrounding the display area D. Furthermore, as shown in Figure 8, the QLED display device 50b includes a resin substrate 10, a TFT layer 20 provided on the resin substrate 10, a QLED element layer 40b provided on the TFT layer 20 as a light-emitting element layer, and a sealing film 45b provided on the QLED element layer 40b.

[0082] As shown in Figure 8, the QLED element layer 40b comprises a plurality of first electrodes 30 stacked sequentially corresponding to a plurality of subpixels P, a common edge cover 31b, a plurality of QLED layers 32, and a common second electrode 33. Here, in the QLED element layer 40b, a plurality of QLED elements 35 corresponding to a plurality of subpixels P are arranged in a matrix.

[0083] The edge cover 31b is provided in a grid pattern over the entire display area D, and as shown in Figure 8, it is provided to cover the peripheral edge of the first electrode 30. Here, the edge cover 31b is made of, for example, a black resin, and is made of an organic resin material such as polyimide resin in which a black pigment such as carbon black is dispersed. Here, the OD value of the edge cover 31b is, for example, 0.6 or more. The film thickness of the edge cover 31b is about the same as the film thickness of the edge cover 31a in the first embodiment described above.

[0084] As shown in Figure 8, the sealing film 45b is provided so as to cover the second electrode 33 and comprises a first inorganic sealing film 41, an organic sealing film 42, and a second inorganic sealing film 43 that are sequentially laminated on the second electrode 33, and has the function of protecting the QLED layer 32 of the QLED element 35 from moisture, oxygen, etc. Furthermore, as shown in Figure 8, in the sealing film 45b, a light-shielding layer 44b is provided in a grid pattern on the side of the first inorganic sealing film 41 opposite to the resin substrate 10, specifically between the first inorganic sealing film 41 and the organic sealing film 42, so as to overlap with the edge cover 31b.

[0085] The light-shielding layer 44b is made of a black resin, and is composed of an organic resin material such as acrylic resin, epoxy resin, silicone resin, polyurea resin, parylene resin, polyimide resin, or polyamide resin in which a black pigment such as carbon black is dispersed. Here, the OD value of the light-shielding layer 44b is, for example, 0.6 or higher. The film thickness of the light-shielding layer 44b is, for example, about 1.5 μm, which is thinner than the film thickness of the light-shielding layer 44a in the first embodiment (about 2 μm).

[0086] The QLED display device 50b described above is configured to display an image by appropriately emitting light from the light-emitting layer 3 of the QLED element 35 via the first TFT 9a and the second TFT 9b at each subpixel P.

[0087] The QLED display device 50b of this embodiment can be manufactured by changing the material and method used to form the edge cover 31a in the QLED element layer formation step of the first embodiment, and by changing the film thickness of the light-shielding layer 44a in the sealing film formation step.

[0088] As described above, in the QLED display device 50b of this embodiment, a light-shielding layer 44b made of black resin is provided between the first inorganic encapsulation film 41 and the organic encapsulation film 42 that constitute the encapsulation film 45b so as to overlap with the edge cover 31b. Therefore, the reflection of external light due to wiring etc. of the TFT layer 20 is suppressed by the light-shielding layer 44b and the edge cover 31b (made of black resin), and reflection suppression performance can be ensured. Furthermore, even if the film thickness of the light-shielding layer 44b made of black resin is increased, it does not significantly affect the coatability of the QLED layer 32 on the resin substrate 10 side, so the coatability of the QLED layer 32 can be ensured. Thus, by using black resin, reflection suppression performance can be ensured and the coatability of the QLED layer 32 can be ensured. In addition, since the light-shielding layer 44b is formed in the encapsulation film 45b and not in the QLED element layer 40b, it is not necessary to consider the effect of degassing from the light-shielding layer 44b, and a lower-cost acrylic resin, for example, can be used instead of polyimide resin, thus reducing manufacturing costs.

[0089] Furthermore, according to the QLED display device 50b of this embodiment, the edge cover 31b is formed of black resin, and the thickness of the light-shielding layer 44b can be made thin, thereby improving the patternability when forming the light-shielding layer 44b.

[0090] <Third Embodiment> Figure 9 shows a third embodiment of the display device according to the present invention. Here, Figure 9 is a cross-sectional view of the display area D of the QLED display device 50c of this embodiment, and corresponds to Figure 6.

[0091] In the first and second embodiments described above, QLED display devices 50a and 50b were illustrated in which light-shielding layers 44a and 44b are provided within the sealing films 45a and 45b. In this embodiment, however, a QLED display device 50c is illustrated in which a light-shielding layer 46a is provided on the sealing film 45c.

[0092] The QLED display device 50c, like the QLED display device 50a of the first embodiment described above, includes a rectangular display area D and a frame-shaped frame area F surrounding the display area D. Furthermore, as shown in Figure 9, the QLED display device 50c includes a resin substrate 10, a TFT layer 20 provided on the resin substrate 10, a QLED element layer 40a provided on the TFT layer 20 as a light-emitting element layer, a sealing film 45c provided on the QLED element layer 40a, and a light-shielding layer 46a provided on the sealing film 45c.

[0093] As shown in Figure 9, the sealing film 45c is provided so as to cover the second electrode 33 and comprises a first inorganic sealing film 41, an organic sealing film 42, and a second inorganic sealing film 43 that are sequentially stacked on the second electrode 33, and has the function of protecting the QLED layer 32 of the QLED element 35 from moisture, oxygen, etc.

[0094] As shown in Figure 9, the light-shielding layer 46a is provided in a grid pattern on the side of the first inorganic encapsulation film 41 opposite to the resin substrate 10, specifically on the second inorganic encapsulation film 43 of the encapsulation film 45c, so as to overlap with the edge cover 31a. Here, the light-shielding layer 46a is made of black resin, and is composed of organic resin materials such as acrylic resin, epoxy resin, silicone resin, polyurea resin, parylene resin, polyimide resin, and polyamide resin in which a black pigment such as carbon black is dispersed. The OD value of the light-shielding layer 46a is, for example, 0.6 or higher. The film thickness of the light-shielding layer 46a is, for example, about 2 μm.

[0095] The QLED display device 50c described above is configured to display an image by appropriately emitting light from the light-emitting layer 3 of the QLED element 35 via the first TFT 9a and the second TFT 9b at each subpixel P.

[0096] The QLED display device 50c of this embodiment can be manufactured by forming a sealing film 45c in the sealing film formation step of the first embodiment without forming a light-shielding layer 44a, and after the sealing film formation step, applying a black-colored photosensitive acrylic resin or the like to the substrate surface on which the sealing film 45c is formed, for example by a spin coating method or a slit coating method, and then patterning the coated film to form a light-shielding layer 46a.

[0097] As described above, in the QLED display device 50c of this embodiment, since the light-shielding layer 46a formed of black resin on the second inorganic encapsulation film 43 of the encapsulation film 45c is provided so as to overlap with the edge cover 31a, the reflection of external light due to wiring etc. of the TFT layer 20 is suppressed by the light-shielding layer 46b, and reflection suppression performance can be ensured. Furthermore, even if the film thickness of the light-shielding layer 46a using black resin is increased, it does not significantly affect the coatability of the QLED layer 32 on the resin substrate 10 side, so the coatability of the QLED layer 32 can be ensured. Therefore, by using black resin, reflection suppression performance can be ensured and the coatability of the QLED layer 32 can be ensured. In addition, since the light-shielding layer 46a is formed on the encapsulation film 45c and not in the QLED element layer 40a, it is not necessary to consider the effect of degassing from the light-shielding layer 46a, and for example, a lower-cost acrylic resin than polyimide resin can be used, thus reducing manufacturing costs.

[0098] Furthermore, according to the QLED display device 50c of this embodiment, since the light-shielding layer 46a is formed on the highly flat organic encapsulation film 42 via a second inorganic encapsulation film 43, the patternability when forming the light-shielding layer 46a can be improved.

[0099] 《Fourth Embodiment》 Figure 10 shows a fourth embodiment of the display device according to the present invention. Here, Figure 10 is a cross-sectional view of the display area D of the QLED display device 50d of this embodiment, and corresponds to Figure 6.

[0100] In the third embodiment described above, a QLED display device 50c in which the edge cover 31a is formed of an inorganic insulating film was exemplified. However, in this embodiment, a QLED display device 50d in which the edge cover 31b is formed of black resin is exemplified.

[0101] The QLED display device 50d, like the QLED display device 50a of the first embodiment described above, includes a rectangular display area D and a frame-shaped frame area F surrounding the display area D. Furthermore, as shown in Figure 10, the QLED display device 50d includes a resin substrate 10, a TFT layer 20 provided on the resin substrate 10, a QLED element layer 40b provided on the TFT layer 20 as a light-emitting element layer, a sealing film 45c provided on the QLED element layer 40b, and a light-shielding layer 46b provided on the sealing film 45c.

[0102] As shown in Figure 10, the light-shielding layer 46b is provided in a grid pattern on the side of the first inorganic encapsulation film 41 opposite to the resin substrate 10, specifically on the second inorganic encapsulation film 43 of the encapsulation film 45c, so as to overlap with the edge cover 31b. Here, the light-shielding layer 46b is made of a black resin, and is composed of an organic resin material such as acrylic resin, epoxy resin, silicone resin, polyurea resin, parylene resin, polyimide resin, or polyamide resin in which a black pigment such as carbon black is dispersed. The OD value of the light-shielding layer 46b is, for example, 0.6 or higher. The film thickness of the light-shielding layer 46b is, for example, about 1.5 μm.

[0103] The QLED display device 50d described above is configured to display an image by appropriately emitting light from the light-emitting layer 3 of the QLED element 35 via the first TFT 9a and the second TFT 9b at each subpixel P.

[0104] The QLED display device 50d of this embodiment can be manufactured by changing the material and method used to form the edge cover 31a in the QLED element layer formation process of the first embodiment, forming a sealing film 45c in the sealing film formation process without forming a light-shielding layer 44a, and then, after the sealing film formation process, applying a black-colored photosensitive acrylic resin or the like to the substrate surface on which the sealing film 45c has been formed, for example by a spin coating method or a slit coating method, and then patterning the coated film to form a light-shielding layer 46b.

[0105] As described above, in the QLED display device 50d of this embodiment, since the light-shielding layer 46b formed of black resin on the second inorganic encapsulation film 43 of the encapsulation film 45c is provided so as to overlap with the edge cover 31b, the reflection of external light due to wiring etc. of the TFT layer 20 is suppressed by the light-shielding layer 46b and the edge cover 31b (formed of black resin), and reflection suppression performance can be ensured. Furthermore, even if the film thickness of the light-shielding layer 46b using black resin is increased, it does not significantly affect the coatability of the QLED layer 32 on the resin substrate 10 side, so the coatability of the QLED layer 32 can be ensured. Therefore, by using black resin, reflection suppression performance can be ensured and the coatability of the QLED layer 32 can be ensured. In addition, since the light-shielding layer 46b is formed on the encapsulation film 45c and not in the QLED element layer 40b, it is not necessary to consider the effect of degassing from the light-shielding layer 46b, and for example, a lower-cost acrylic resin can be used instead of polyimide resin, thus reducing manufacturing costs.

[0106] Furthermore, according to the QLED display device 50d of this embodiment, the edge cover 31b is formed of black resin, the thickness of the light-shielding layer 46b can be made thin, and since the light-shielding layer 46b is formed on the highly flat organic encapsulation film 42 via the second inorganic encapsulation film 43, the patternability when forming the light-shielding layer 46b can be further improved.

[0107] <Other Embodiments> In the above embodiments, QLED display devices in which the first electrode is the anode and the second electrode is the cathode were illustrated. However, the present invention can also be applied to QLED display devices in which the stacked structure of the QLED layer is reversed, with the first electrode being the cathode and the second electrode being the anode.

[0108] Furthermore, while the above embodiments illustrate QLED display devices in which the electrode of the TFT connected to the first electrode is used as the drain electrode, the present invention can also be applied to QLED display devices in which the electrode of the TFT connected to the first electrode is called the source electrode.

[0109] Furthermore, although the above embodiments have described a QLED display device as an example, the present invention can be applied to a display device equipped with a plurality of light-emitting elements driven by electric current, and can be applied to an organic EL display device using OLEDs, for example.

[0110] As described above, the present invention is useful for self-illuminating display devices.

[0111] B Folding section D Display area F Frame area Lb Blue light-emitting area Lg Green light-emitting area Lr Red light-emitting area P, Pb, Pg, Pr Subpixels T Terminal section 1 Hole injection layer 2 Hole transport layer 3 Light-emitting layer 3b Blue light-emitting layer 3g Green light-emitting layer 3r Red light-emitting layer 4 Electron transport layer 5 Electron injection layer 9a First TFT 9b Second TFT 9c Capacitor 10 Resin substrate (base substrate) 11 Base coat film 12a, 12b Semiconductor layer 13 Gate insulating film 14a, 14b Gate electrode 14c Lower conductive layer 14g Gate wire 15 First interlayer insulating film 16c Upper conductive layer 17 Second interlayer insulating film 18a, 18c Source electrode 18b, 18d Drain electrode 18f Source wire 18g Power line 19 Planarization film 20 TFT layer (thin film transistor layer) 30 First electrode 31a, 31b Edge cover 32 QLED layer (quantum dot light-emitting diode layer, light-emitting functional layer) 33 Second electrode 35 QLED element 40a, 40b QLED element layer (light-emitting element layer) 41 First inorganic encapsulation film 42 Organic encapsulation film 43 Second inorganic encapsulation film 44a, 44b, 46a, 46b Light-shielding layer 45a, 45b, 45c Encapsulation film 50a, 50b, 50c, 50d QLED display device

Claims

1. A display device comprising: a base substrate; a thin film transistor layer provided on the base substrate; a light-emitting layer provided on the thin film transistor layer, wherein a plurality of first electrodes, a common edge cover, a plurality of light-emitting functional layers, and a common second electrode are sequentially laminated corresponding to a plurality of subpixels constituting a display area; and a sealing film provided on the light-emitting layer, wherein a first inorganic sealing film, an organic sealing film, and a second inorganic sealing film are sequentially laminated, wherein the edge cover is provided so as to cover the peripheral end of each of the plurality of first electrodes, and a light-shielding layer made of black resin is provided on the side of the first inorganic sealing film opposite to the base substrate so as to overlap with the edge cover.

2. A display device according to claim 1, characterized in that the light-shielding layer is provided between the first inorganic encapsulation film and the organic encapsulation film.

3. A display device according to claim 1, characterized in that the light-shielding layer is provided on the second inorganic encapsulation film.

4. A display device according to any one of claims 1 to 3, characterized in that the edge cover is formed of an inorganic insulating film.

5. A display device according to any one of claims 1 to 3, characterized in that the edge cover is formed of black resin to be thinner than the film thickness of the light-shielding layer.

6. A display device according to any one of claims 1 to 5, characterized in that at least one of the plurality of light-emitting functional layers is a quantum dot light-emitting diode layer.

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