Display device and display device manufacturing method

Abstract

A display device (1) comprises: a substrate (2); a plurality of light-emitting elements (10R, 10G, 10B) each formed by laminating, on the substrate (2), a lower electrode (5), a functional layer (FCR, FCG, FCB) including a light-emitting layer (REM, GEM, BEM), and an upper electrode (8) in this order from the substrate (2) side; a first passivation film (12) that is disposed so as to cover at least the upper electrodes (8) of the respective light-emitting elements (10R, 10G, 10B) and that has first contact holes (12C1-12C6) disposed at positions overlapping the upper electrodes (8) in plan view; and a conductive layer (13) that electrically connects the upper electrodes (8) via the first contact holes (12C1-12C6).

Description

Display device and method for manufacturing a display device

[0001] The present disclosure relates to a display device and a method for manufacturing a display device.

[0002] In recent years, various display devices have been developed as light-emitting devices provided with light-emitting elements. In particular, display devices provided with QLED (Quantum dot Light Emitting Diode) or OLED (Organic Light Emitting Diode) have attracted high attention because they can achieve low power consumption, thinning, and high image quality.

[0003] For example, Patent Document 1 describes a display device in which upper electrodes of a plurality of light-emitting elements are provided so as to be in contact with side surfaces of a conductive partition wall that is formed prior to a functional layer including a light-emitting layer provided in the light-emitting element and an upper electrode and is located between the plurality of light-emitting elements.

[0004] Japanese Patent Application Laid-Open No. 2023-102959

[0005] However, since the display device described in Patent Document 1 employs a structure in which the upper electrode provided in the light-emitting element is in contact with the side surface of the partition wall without passing through a contact hole, there is a problem that contact defects are likely to occur structurally between the upper electrode and the side surface of the partition wall.

[0006] An aspect of the present disclosure aims to provide a display device in which contact defects between upper electrodes of a plurality of light-emitting elements and a conductive layer that electrically connects the upper electrodes of the plurality of light-emitting elements are suppressed, and a method for manufacturing a display device.

[0007] To solve the aforementioned problems, the display device of the present disclosure includes: a substrate; a plurality of light-emitting elements formed on the substrate by stacking a lower electrode, a functional layer including a light-emitting layer, and an upper electrode in this order from the substrate side; a first passivation film provided so as to cover at least the upper electrode of each of the plurality of light-emitting elements and having a first contact hole provided at a position that overlaps with the upper electrode in a plan view; and a conductive layer that electrically connects the upper electrodes through the first contact holes.

[0008] To solve the above problems, the method for manufacturing a display device of the present disclosure includes the steps of: forming a plurality of lower electrodes on a substrate; forming a plurality of light-emitting elements by patterning, in which the lower electrodes, a functional layer including a light-emitting layer, and an upper electrode are stacked in this order from the substrate side at positions that overlap with each of the plurality of lower electrodes in a plan view; forming a first passivation film, performed after the step of forming the plurality of light-emitting elements by patterning, which covers at least the upper electrode of each of the plurality of light-emitting elements and has a first contact hole provided at a position that overlaps with each of the upper electrodes in a plan view; and forming a conductive layer that electrically connects each of the upper electrodes through the first contact holes.

[0009] According to one aspect of this disclosure, a display device in which contact failures between the upper electrodes and conductive layers of each of a plurality of light-emitting elements are suppressed, and a method for manufacturing the display device can be provided.

[0010] Figure 1 is a plan view showing the schematic configuration of the display device of Embodiment 1. Figure 1 is a cross-sectional view showing the schematic configuration of the display area of ​​the display device of Embodiment 1 shown in Figure 1. Figure 1 is a plan view showing a magnified view of one pixel in the display area of ​​the display device of Embodiment 1 shown in Figure 1. Figure 2 is a diagram showing part of the manufacturing process of the display device of Embodiment 1. Figure 3 is a diagram showing part of the manufacturing process of the display device of Embodiment 1 that is performed after the manufacturing process of the display device of Embodiment 1 shown in Figure 4. Figure 4 is a diagram showing part of the manufacturing process of the display device of Embodiment 1 that is performed after the manufacturing process of the display device of Embodiment 1 shown in Figure 5. Figure 6 is a diagram showing part of the manufacturing process of the display device of Embodiment 1 that is performed after the manufacturing process of the display device of Embodiment 1 shown in Figure 6. Figure 2 is a plan view showing a magnified view of one pixel in the display area of ​​the display device of Embodiment 2. Figure 8 is a cross-sectional view along the line X-X' in Figure 8, showing the schematic configuration of the display area of ​​the display device of Embodiment 2 shown in Figure 8. Figure 8 is a cross-sectional view along the line Y-Y' in Figure 8, showing the schematic configuration of the display area of ​​the display device of Embodiment 2 shown in Figure 8. Figure 8 is a cross-sectional view along the line Z-Z' in Figure 8, showing the schematic configuration of the display area of ​​the display device of Embodiment 2 shown in Figure 8. Figure 8 is a diagram showing an example of a conductive layer provided in the display area of ​​the display device of Embodiment 2 shown in Figure 8. This figure shows an example of a conductive layer provided in the display area of ​​a display device, which is a modified example of the display device of Embodiment 2 shown in Figure 8.

[0011] The embodiments of this disclosure will be described below with reference to Figures 1 to 13. For the sake of convenience, in the following, components having the same function as those described in a particular embodiment will be denoted by the same reference numerals, and their descriptions may be omitted.

[0012] [Embodiment 1] Figure 1 is a plan view showing the schematic configuration of the display device 1 of Embodiment 1. Figure 2 is a cross-sectional view showing the schematic configuration of the display area DA of the display device 1 of Embodiment 1 shown in Figure 1. Figure 3 is a plan view showing an enlarged view of one pixel PIX in the display area DA of the display device 1 of Embodiment 1 shown in Figure 1.

[0013] As shown in Figure 1, the display device 1 comprises a frame area NDA and a display area DA. The display area DA of the display device 1 is provided with a plurality of pixels PIX, and each pixel PIX includes a red subpixel RSP, a blue subpixel BSP, and a green subpixel GSP. In this embodiment, the case in which one pixel PIX is composed of a red subpixel RSP, a blue subpixel BSP, and a green subpixel GSP is described as an example, but it is not limited to this. For example, one pixel PIX may include subpixels of other colors in addition to the red subpixel RSP, blue subpixel BSP, and green subpixel GSP.

[0014] As shown in Figures 1, 2, and 3, the display device 1 includes a plurality of light-emitting elements in the display area DA. In this embodiment, the plurality of light-emitting elements are described as including a red light-emitting element 10R (first light-emitting element) containing a red light-emitting layer REM (first light-emitting layer), a blue light-emitting element 10B (second light-emitting element) containing a blue light-emitting layer BEM (second light-emitting layer), and a green light-emitting element 10G (third light-emitting element) containing a green light-emitting layer GEM (third light-emitting layer), but the embodiment is not limited to this.

[0015] In this embodiment, we will explain using as an example the case in which the display area DA of the display device 1 includes a red subpixel RSP which contains the red light-emitting element 10R shown in Figure 2, a blue subpixel BSP which contains the blue light-emitting element 10B shown in Figure 2, and a green subpixel GSP which contains the green light-emitting element 10G. As shown in Figure 1, the frame area NDA of the display device 1 is provided with terminal sections TER for wiring to drive the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G shown in Figure 2.

[0016] As shown in Figure 2, the display device 1 comprises a substrate 2, a red light-emitting element 10R, a blue light-emitting element 10B, and a green light-emitting element 10G provided on the substrate 2, a first passivation film 12 provided so as to cover at least the upper electrodes 8 of the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, and having first contact holes 12C1 to 12C6 provided in positions that overlap with the upper electrodes 8 in a plan view, a second passivation film 11R provided between the upper electrode 8 of the red light-emitting element 10R and the first passivation film 12 so as to be in contact with both the upper electrode 8 of the red light-emitting element 10R and the first passivation film 12, and having second contact holes 11RC1 and 11RC2, and the upper electrode 8 of the blue light-emitting element 10B and the first The present invention includes a third passivation film 11B provided between the passivation film 12 and the upper electrode 8 provided on the blue light-emitting element 10B and the first passivation film 12, and having second contact holes 11BC1 and 11BC2; a fourth passivation film 11G provided between the upper electrode 8 provided on the green light-emitting element 10G and the first passivation film 12, and having second contact holes 11GC1 and 11GC2; and a conductive layer 13 that electrically connects each upper electrode 8 via the respective first contact holes 12C1 to 12C6 and the respective second contact holes 11RC1, 11RC2, 11BC1, 11BC2, 11GC1, and 11GC2. In this embodiment, the display device 1 is described as having a passivation film that includes a first passivation film 12, as well as a second passivation film 11R, a third passivation film 11B, and a fourth passivation film 11G. However, the invention is not limited to this, and the display device 1 may have only the first passivation film 12 as a passivation film. In this case, the conductive layer 13 electrically connects each of the upper electrodes 8 through their respective first contact holes 12C1 to 12C6.With this configuration, the conductive layer 13 that electrically connects the upper electrodes 8 of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G is provided so as to be in contact with the upper surfaces of the upper electrodes 8 of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G via first contact holes 12C1 to 12C6 provided in the first passivation film 12. As a result, the portion in contact between the conductive layer 13 and the upper electrodes 8 is protected by the first passivation film 12, and contact failures between the conductive layer 13 and the upper electrodes 8 can be suppressed. In this embodiment, the red light-emitting element 10R is formed by stacking a lower electrode 5, a functional layer FCR including a red light-emitting layer REM, and an upper electrode 8 in this order from the substrate 2 side. The blue light-emitting element 10B is formed by stacking a lower electrode 5, a functional layer FCB including a blue light-emitting layer BEM, and an upper electrode 8 in this order from the substrate 2 side. The green light-emitting element 10G is formed by stacking a lower electrode 5, a functional layer FCG including a green light-emitting layer GEM, and an upper electrode 8 in this order from the substrate 2 side. In this embodiment, the case in which the display device 1 is equipped with a red light-emitting element 10R, a blue light-emitting element 10B, and a green light-emitting element 10G is described as an example, but the invention is not limited to this, and the display device 1 may be equipped with, for example, a plurality of light-emitting elements that emit a specific color.

[0017] As shown in Figure 2, in this embodiment, we will explain using the example that each of the functional layers FCR including the red light-emitting layer REM of the red light-emitting element 10R, the functional layer FCB including the blue light-emitting layer BEM of the blue light-emitting element 10B, and the functional layer FCG including the green light-emitting layer GEM of the green light-emitting element 10G are constructed by laminating the lower charge transport layer, the corresponding color light-emitting layer, and the upper charge transport layer in this order from the substrate 2 side, but we are not limited to this. For example, each of the functional layers FCR including the red light-emitting layer REM, the functional layer FCB including the blue light-emitting layer BEM, and the functional layer FCG including the green light-emitting layer GEM may consist only of the corresponding color light-emitting layer, or it may consist of one of the lower charge transport layer and the upper charge transport layer and the corresponding color light-emitting layer.

[0018] As shown in Figure 2, in this embodiment, we will explain using as an example the case in which each of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G is provided with an anode as the lower electrode 5, a hole injection layer as the first lower charge transport layer 6HI which is the lower layer constituting the lower charge transport layer, a hole transport layer as the second lower charge transport layer 6HT which is the upper layer constituting the lower charge transport layer, an electron transport layer as the upper charge transport layer 7ET, and a cathode as the upper electrode 8. However, we are not limited to this, and for example, between the light-emitting layer of the corresponding color and the upper electrode 8, there may be an electron transport layer as the first upper charge transport layer which is the lower layer constituting the upper charge transport layer 7ET, and an electron injection layer as the second upper charge transport layer which is the upper layer constituting the upper charge transport layer 7ET. That is, in the case where each of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G is provided with an anode as a lower electrode 5 and a cathode as an upper electrode 8, and a lower charge transport layer is provided, the lower charge transport layer may be at least one of a hole injection layer and a hole transport layer, and if an upper charge transport layer is provided, the upper charge transport layer may be at least one of an electron transport layer and an electron injection layer.

[0019] On the other hand, each of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G may have a cathode as the lower electrode 5 and an anode as the upper electrode 8. In this case, if a lower charge transport layer is provided, the lower charge transport layer may be at least one of an electron injection layer and an electron transport layer, and if an upper charge transport layer is provided, the upper charge transport layer may be at least one of a hole transport layer and a hole injection layer.

[0020] Furthermore, the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G shown in Figure 2 may be either top-emission or bottom-emission types. The red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G have a sequential stacking structure in which the cathode, which is the upper electrode 8, is positioned above the anode, which is the lower electrode 5. To make it a top-emission type, the anode, which is the lower electrode 5, is an electrode that reflects visible light, and the cathode, which is the upper electrode 8, is an electrode that transmits visible light. To make it a bottom-emission type, the anode, which is the lower electrode 5, is an electrode that transmits visible light, and the cathode, which is the upper electrode 8, is an electrode that reflects visible light. On the other hand, in the case of an inverted stack structure in which the anode, which is the upper electrode, is positioned above the cathode, which is the lower electrode 5, in order to make it a top emission type, the cathode, which is the lower electrode 5, is an electrode that reflects visible light and the anode, which is the upper electrode 8, is an electrode that transmits visible light. In order to make it a bottom emission type, the cathode, which is the lower electrode 5, is an electrode that transmits visible light and the anode, which is the upper electrode 8, is an electrode that reflects visible light.

[0021] The electrodes that reflect visible light are not particularly limited in terms of the material used to form them, as long as they can reflect visible light and are conductive. For example, they may be formed using metallic materials such as Al, Mg, Li, and Ag, or alloys of the metallic materials, or laminates of the metallic materials and transparent metal oxides (e.g., indium tin oxide, indium zinc oxide, indium gallium zinc oxide, etc.), or laminates of the alloys and the transparent metal oxides.

[0022] On the other hand, electrodes that transmit visible light are not particularly limited in terms of the material used to form them, as long as they can transmit visible light and are conductive. For example, they may be formed using a thin film made of a transparent metal oxide (e.g., indium tin oxide, indium zinc oxide, indium gallium zinc oxide, etc.) or a metallic material such as Al or Ag, or a nanowire made of a metallic material such as Al or Ag.

[0023] In this embodiment, as shown in Figure 2, the second passivation film 11R has second contact holes 11RC1 and 11RC2 formed in a position that overlaps with the respective first contact holes 12C1 and 12C2 provided in the first passivation film 12 in a plan view, the third passivation film 11B has second contact holes 11BC1 and 11BC2 formed in a position that overlaps with the respective first contact holes 12C3 and 12C4 provided in the first passivation film 12 in a plan view, and the fourth passivation film 11G has second contact holes 11GC1 and 11GC2 formed in a position that overlaps with the respective first contact holes 12C5 and 12C6 provided in the first passivation film 12 in a plan view. Furthermore, the conductive layer 13 electrically connects the upper electrodes 8 of the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, respectively, through the first contact holes 12C1 to 12C6 and the second contact holes 11RC1, 11RC2, 11BC1, 11BC2, 11GC1, and 11GC2. In other words, the conductive layer 13 electrically connects the upper electrodes 8 of the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G via contact holes CH1 and CH2, which consist of a first contact hole 12C1 and a second contact hole 11RC1, and a first contact hole 12C2 and a second contact hole 11RC2, provided on the red light-emitting element 10R; contact holes CH3 and CH4, which consist of a first contact hole 12C3 and a second contact hole 11BC1, and a first contact hole 12C4 and a second contact hole 11BC2, provided on the blue light-emitting element 10B; and contact holes CH5 and CH6, which consist of a first contact hole 12C5 and a second contact hole 11GC1, and a first contact hole 12C6 and a second contact hole 11GC2, provided on the green light-emitting element 10G.According to the display device 1, the conductive layer 13 that electrically connects the upper electrodes 8 of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G is provided so as to be in contact with the upper surfaces of the upper electrodes 8 of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G via contact holes CH1 to CH6 provided in either the second passivation film 11R, the third passivation film 11B, and the fourth passivation film 11G and the first passivation film 12. Therefore, the portion in contact between the conductive layer 13 and the upper electrodes 8 is protected by either the second passivation film 11R, the third passivation film 11B, and the fourth passivation film 11G and the first passivation film 12, thereby suppressing contact failures between the conductive layer 13 and the upper electrodes 8.

[0024] As described above, in this embodiment, an example has been given in which a second passivation film 11R is provided on the red light-emitting element 10R, a third passivation film 11B is provided on the blue light-emitting element 10B, and a fourth passivation film 11G is provided on the green light-emitting element 10G, along with the first passivation film 12. However, the embodiment is not limited to this. If a conductive layer 13 that electrically connects the upper electrodes 8 of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G can be provided so as to be in contact with the upper surfaces of the upper electrodes 8 of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G via contact holes, then it is not necessary to provide one or more of the second passivation film 11R, third passivation film 11B, and fourth passivation film 11G, for example, all of the second passivation film 11R, third passivation film 11B, and fourth passivation film 11G.

[0025] As shown in Figure 2, in the display device 1, it is preferable that the first passivation film 12 is also formed between the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G so as to cover the side walls of each of them. With this configuration, insulation between each of the functional layer FCR including the red light-emitting layer REM, the functional layer FCB including the blue light-emitting layer BEM, and the functional layer FCG including the green light-emitting layer GEM and the conductive layer 13 can be more reliably ensured.

[0026] Furthermore, as shown in Figure 2, in the display device 1, it is preferable that the first passivation film 12 is also formed between the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G. With this configuration, even if wiring or the like, formed as the same layer as the lower electrode 5 and the upper electrode 8, is provided between the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, the wiring can be covered by the first passivation film 12 provided between the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, so that the position of providing the conductive layer 13 between the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G can be freely selected.

[0027] As shown in Figure 2, the display device 1 includes a support substrate 51. In the display area DA of the display device 1, a barrier layer 52, a thin-film transistor layer 3 including transistors, a red light-emitting element 10R, a blue light-emitting element 10B, a green light-emitting element 10G and bank 4, and a sealing layer 24 are provided on the support substrate 51 in this order from the support substrate 51 side. The substrate 2 includes the support substrate 51, the barrier layer 52, and the thin-film transistor layer 3 including transistors.

[0028] The support substrate 51 may be a resin substrate made of a resin material such as polyimide, or it may be a glass substrate. In this embodiment, since the display device 1 is a flexible display device, the case in which a resin substrate made of a resin material such as polyimide is used as the support substrate 51 will be described as an example, but it is not limited to this. When the display device 1 is a non-flexible display device, a glass substrate can be used as the support substrate 51.

[0029] The barrier layer 52 is a layer that prevents foreign substances such as water and oxygen from entering the transistor, the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G. For example, it can be composed of a silicon oxide film, a silicon nitride film, or a silicon oxynitride film, or a laminate of these, formed by the CVD method.

[0030] The transistor included in the thin-film transistor layer 3 includes, for example, a semiconductor film 53, a gate insulating film 54, a gate electrode 55, an interlayer insulating film 56, a source electrode 57S and a drain electrode 57D, and a first planarization film 58. The source electrode 57S is in contact with one end of the semiconductor film 53 via a contact hole 54C provided in the gate insulating film 54 and a contact hole 56C provided in the interlayer insulating film 56, and the drain electrode 57D is in contact with the other end of the semiconductor film 53 via another contact hole 54C provided in the gate insulating film 54 and another contact hole 56C provided in the interlayer insulating film 56.

[0031] In the thin-film transistor layer 3 containing the transistor, in a plan view, the region where the transistor is located includes the semiconductor film 53, the gate insulating film 54, the gate electrode 55, the interlayer insulating film 56, the source electrode 57S and the drain electrode 57D, the first planarization film 58, the conductive member 59 that electrically connects the drain electrode 57D and the lower electrode 5, and the second planarization film 60. In a plan view, the region where the transistor is not located includes the gate insulating film 54, the interlayer insulating film 56, the first planarization film 58, and the second planarization film 60. The conductive member 59 is in contact with the drain electrode 57D via a contact hole 58C provided in the first planarization film 58, and the lower electrode 5 is in contact with the conductive member 59 via a contact hole 60C provided in the second planarization film 60.

[0032] The semiconductor film 53 may be made of, for example, low-temperature polysilicon (LTPS) or an oxide semiconductor (for example, an In-Ga-Zn-O semiconductor). In this embodiment, the case where the transistor has a top gate structure is given as an example, but it is not limited to this, and the transistor may have a bottom gate structure.

[0033] The gate electrode 55, source electrode 57S, drain electrode 57D, and conductive member 59 can be made of a single-layer or multilayer film of a metal containing, for example, at least one of aluminum, tungsten, molybdenum, tantalum, chromium, titanium, or copper.

[0034] The gate insulating film 54 and the interlayer insulating film 56 can be composed of, for example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a laminate of these, formed by a CVD method.

[0035] The first planarization film 58 and the second planarization film 60 can be made of, for example, a coatable organic material such as polyimide or acrylic.

[0036] The red light-emitting element 10R includes a lower electrode 5, a functional layer FCR including a red light-emitting layer REM, and an upper electrode 8. The blue light-emitting element 10B includes a lower electrode 5, a functional layer FCB including a blue light-emitting layer BEM, and an upper electrode 8. The green light-emitting element 10G includes a lower electrode 5, a functional layer FCG including a green light-emitting layer GEM, and an upper electrode 8. The bank 4 covering the edge of the lower electrode 5 can be formed, for example, by coating an organic material such as polyimide or acrylic and then patterning it using photolithography. As shown in Figure 2, the display device 1 includes a bank 4 provided so as to be in contact with at least a portion of the end of the lower electrode 5, and a portion of the first passivation film 12 formed between the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, i.e., the portion of the first passivation film 12 formed between the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, may overlap with the bank 4 in a plan view. In this embodiment, the case in which bank 4 is provided is given as an example for explanation, but bank 4 is not required.

[0037] The second passivation film 11R provided on the red light-emitting element 10R, the third passivation film 11B provided on the blue light-emitting element 10B, and the fourth passivation film 11G provided on the green light-emitting element 10G may each be formed from the same material, or some of the passivation films may be formed from different materials. The second passivation film 11R, the third passivation film 11B, and the fourth passivation film 11G are preferably films that have moisture-proof and etching-resistant properties for the purpose of protecting the underlying layer. The second passivation film 11R, the third passivation film 11B, and the fourth passivation film 11G may be formed from, for example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a laminate of these, formed by a vapor deposition method such as CVD, but are not limited thereto, and may also be formed from films formed by, for example, a sputtering method.

[0038] The first passivation film 12 is preferably a film having moisture-proof and etching-resistant properties for the purpose of protecting the underlying layer. The first passivation film 12 may be formed by a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a laminate of these, for example, by a vapor deposition method such as CVD, but is not limited thereto, and may also be formed by a film formed using a sputtering method, for example.

[0039] The conductive layer 13 may be made of, for example, a transparent metal oxide (e.g., indium tin oxide, indium zinc oxide, indium gallium zinc oxide, etc.), or a single-layer or multilayer film of a metal containing at least one of aluminum, tungsten, molybdenum, tantalum, chromium, titanium, or copper, or it may be made of, for example, Ag or MgAg, which are commonly used when forming the lower electrode 5 or upper electrode 8 as a cathode.

[0040] The sealing layer 24 is preferably a translucent film when the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G are all of the top-emission type. The sealing layer 24 can be composed of, for example, a first sealing film 21 that covers the first passivation film 12 and the conductive layer 13, a second sealing film 22 that is above the first sealing film 21, and a third sealing film 23 that is above the second sealing film 22. The sealing layer 24 prevents foreign substances such as water and oxygen from penetrating the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G.

[0041] For example, the first sealing film 21 and the third sealing film 23 may be formed of an inorganic film, and the second sealing film 22 may be formed of an organic film. The first sealing film 21 and the third sealing film 23 which are inorganic films may be formed by, for example, a CVD method, and may be composed of a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a laminated film thereof. The second sealing film 22 which is an organic film may be a light-transmissive organic film having a planarizing effect, and can be composed of, for example, an organic material such as acrylic that can be applied. The second sealing film 22 which is an organic film may be formed by, for example, an inkjet method.

[0042] As the material used for forming the hole injection layer (HIL) provided as the first lower charge transport layer 6HI, there is no particular limitation as long as it is a hole injection material capable of stabilizing the injection of holes into the light-emitting layer. For example, a composite of poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrene sulfonic acid (PSS) (PEDOT:PSS) can be used.

[0043] As the material used for forming the hole transport layer (HTL) provided as the second lower charge transport layer 6HT, for example, organic materials such as poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl))diphenylamine)] (TFB), N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)-benzidine (poly-TPD) or polyvinylcarbazole (PVK) may be used, or nanoparticles having hole transport properties such as NiO particles may be used.

[0044] As the material used for forming the electron transport layer (ETL) provided as the upper charge transport layer 7ET, for example, organic materials such as 2,2',2''-(1,3,5-benzenetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) may be used, or nanoparticles having electron transport properties such as ZnO particles or particles of an oxide containing Zn and Mg may be used.

[0045] Furthermore, if an electron injection layer (EIL) is provided between the upper charge transport layer 7ET and the upper electrode 8, which is the cathode, the material used to form the electron injection layer (EIL) is not particularly limited as long as it is an electron-injection material that can stabilize the injection of electrons into the light-emitting layer. For example, alkali metals or alkaline earth metals such as aluminum, strontium, calcium, lithium, cesium, magnesium oxide, aluminum oxide, strontium oxide, lithium oxide, lithium fluoride, magnesium fluoride, strontium fluoride, calcium fluoride, barium fluoride, cesium fluoride, polymethyl methacrylate, sodium polystyrene sulfonate, alkali metals or alkaline earth metals, oxides of alkali metals or alkaline earth metals, fluorides of alkali metals or alkaline earth metals, or organic complexes of alkali metals can be used.

[0046] In each embodiment of this disclosure, the red light-emitting layer REM of the red light-emitting element 10R, the blue light-emitting layer BEM of the blue light-emitting element 10B, and the green light-emitting layer GEM of the green light-emitting element 10G are each light-emitting layers containing quantum dots, and the case in which the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G are QLEDs (Quantum dot Light Emitting Diodes) is described as an example, but is not limited thereto. For example, the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G may be OLEDs (Organic Light Emitting Diodes) that have a light-emitting layer containing an organic light-emitting material instead of a light-emitting layer containing quantum dots.

[0047] A quantum dot is a semiconductor nanoparticle that emits light when excitons are generated by injected electrons and holes, and when the excitons lose energy, the electrons and holes recombine. A quantum dot may have a core / shell structure, for example, that includes a core and a shell that covers at least a portion of the surface of the core. The shell may be a single layer, a multi-shell consisting of multiple layers containing different materials, or a giant shell with a thickness of 2 nm or more.

[0048] Quantum dots may contain materials used for conventionally known core materials and shell materials in the respective materials of the core and the shell. Quantum dots may have, for example, a core / shell structure including group I-III-V chalcogenide-based materials / ZnS such as InP / ZnS, CdSe / ZnS, CdSe / ZnSe, CdSe / CdS, ZnSe / ZnS or CuInGaS (CIGS). In addition, quantum dots may contain InZnP, CdSeTe, or ZnSeTe. Further, the core of the quantum dots may contain CuInZnS, CuInS, CuGaS, AgInS, or ZnAgInS. Note that the shell may be formed of a plurality of layers including a plurality of different materials.

[0049] The particle size of the quantum dots is about 1 to 100 nm. The quantum dots may have a spherical shape or a non-spherical shape. In the present disclosure, the particle size of the quantum dots may be measured by performing cross-sectional observation in the film thickness direction for each of the red emission layer REM, the blue emission layer BEM, and the green emission layer GEM. In the cross-sectional observation, each particle size of the quantum dots may be regarded as the same as the diameter of a circle having the same area as the respective cross-sectional areas. The particle size of the quantum dots may be measured by measuring 20 particle sizes in the cross-sectional observation and calculating the average thereof. The cross-sectional observation may be performed by analyzing an image obtained by imaging a cross section of each layer as a transmission electron microscope image (TEM image).

[0050] As shown in Figure 2, in the display device 1, a lower film 14 made of the same material as the lower charge transport layer may be provided between each of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G. In this embodiment, each of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G is provided with a lower charge transport layer consisting of a first lower charge transport layer 6HI and a second lower charge transport layer 6HT, and a laminate of a first lower charge transport layer 6HI' made of the same material as the first lower charge transport layer 6HI and a second lower charge transport layer 6HT' made of the same material as the second lower charge transport layer 6HT is provided as the lower film 14. As shown in Figure 2, in the display device 1, the lower film 14 may be covered with a first passivation film 12 and a conductive layer 13. Furthermore, as shown in Figure 2, the display device 1 includes a bank 4 provided so as to be in contact with at least a portion of the end of the lower electrode 5, and the lower membrane 14 may be provided on the bank 4.

[0051] When the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G are of the top-emission type, it is preferable that the conductive layer 13 is formed of a material that transmits visible light, for example, a transparent metal oxide (for example, indium tin oxide, indium zinc oxide, indium gallium zinc oxide, etc.).

[0052] In this embodiment, the conductive layer 13 of the display device 1 is described as being provided in such a way that, in a plan view, it overlaps with a part of the display area DA where the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G are provided, as shown in Figure 3, but the embodiment is not limited to this. For example, if the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G are of the top-emission type and the conductive layer 13 is made of a material that transmits visible light, the conductive layer 13 may be provided in such a way that, in a plan view, it overlaps with the entire display area DA where the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G are provided. Furthermore, if the conductive layer 13 is a metal wiring, that is, by forming the conductive layer 13 in a wiring shape using a metal material, a conductive layer with high electrical conductivity that can be suitably used whether the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G are of the top-emission type or the bottom-emission type can be realized.

[0053] As shown in Figure 3, the display device 1 includes a pixel PIX comprising a red subpixel RSP (first subpixel) containing a red light-emitting element 10R (first light-emitting element), a blue subpixel BSP (second subpixel) containing a blue light-emitting element 10B (second light-emitting element), and a green subpixel GSP (third subpixel) containing a green light-emitting element 10G (third light-emitting element). The conductive layer 13 preferably overlaps with the respective first contact holes 12C1 to 12C6, which are located in positions overlapping with the upper electrodes 8 of the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, respectively, in a plan view, and also includes a portion that crosses the pixel PIX. In this embodiment, as shown in Figure 3, the conductive layer 13 preferably overlaps with the contact hole CH1 consisting of a first contact hole 12C1 and a second contact hole 11RC1, the contact hole CH2 consisting of a first contact hole 12C2 and a second contact hole 11RC2, the contact hole CH3 consisting of a first contact hole 12C3 and a second contact hole 11BC1, the contact hole CH4 consisting of a first contact hole 12C4 and a second contact hole 11BC2, the contact hole CH5 consisting of a first contact hole 12C5 and a second contact hole 11GC1, and the contact hole CH6 consisting of a first contact hole 12C6 and a second contact hole 11GC2, and also includes a portion that crosses the pixel PIX. In this embodiment, as shown in Figure 3, the conductive layer 13 is formed to include a portion that crosses the pixel PIX at the shortest distance, i.e., a linear portion, but is not limited to this. Bank 4 has an opening 4K, shown by a dotted line in Figure 3, in the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, respectively.Furthermore, at the opening 4K of bank 4, the lower electrode 5 is in contact with the functional layer FCR including the red light-emitting layer REM, the functional layer FCB including the blue light-emitting layer BEM, and the functional layer FCG including the green light-emitting layer GEM, respectively. As a result, the opening 4K of bank 4 becomes the effective light-emitting region of the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, respectively. Therefore, in this embodiment, as shown in Figure 3, contact holes CH1 to CH6 are provided on the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, respectively, outside the above-mentioned effective light-emitting region in a plan view, thereby avoiding the influence of the contact holes CH1 to CH6 on the effective light-emitting region.

[0054] As described above, in this embodiment, we will explain using the example of providing two contact holes CH1 to CH2 on the red light-emitting element 10R, two contact holes CH3 to CH4 on the blue light-emitting element 10B, and two contact holes CH5 to CH6 on the green light-emitting element 10G. However, we are not limited to this, and the number of contact holes provided on each light-emitting element can be determined as appropriate, and the number of contact holes provided on each light-emitting element may differ for each color. Furthermore, in this embodiment, we will explain using the example of providing contact holes CH1 to CH6 outside the above-described effective light-emitting regions of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G. However, as in Embodiment 2 described later, contact holes may also be provided within the above-described effective light-emitting regions of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G.

[0055] As shown in Figure 1, the display device 1 is equipped with terminals TER for wiring to drive the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, and it is preferable that the terminals TER are made of the same material as the conductive layer 13. With this configuration, the conductive layer 13 can be formed in the terminal TER formation process without having to perform a separate process for forming the conductive layer 13.

[0056] Based on Figures 4, 5, 6, and 7, the manufacturing method of the display device 1 described later includes a step of forming a light-emitting element by patterning (steps S3 to S14 shown in Figures 4 and 5). In a patterning step using a normal photolithography method, for example, in the case of a light-emitting layer, after forming the light-emitting layer, a resist layer is applied thereon, an etching step is performed using the resist layer as a mask, and then a peeling step of the resist layer is performed. In this case, it has been confirmed that the light-emitting properties of the light-emitting layer deteriorate when the resist layer, peeling solution and washing water come into direct contact with the light-emitting layer. The mechanism of deterioration is not known, but it has been confirmed that the light-emitting intensity decreases in photoluminescence evaluation after the material single film comes into contact with a solvent or water. Therefore, in the process of forming the light-emitting elements by patterning (steps S3 to S14 shown in Figures 4 and 5) included in the manufacturing method of the display device 1, all the necessary layers for each color of light-emitting element are first laminated so that the surface of the light-emitting layer is not exposed to the resist layer, stripping solution, and washing water, and more preferably, a passivation film is further laminated before applying the resist layer and performing patterning to form each color of light-emitting element. According to the manufacturing method of the display device 1, the sidewall portion of the light-emitting layer is exposed to solvents such as stripping solution and washing water, but most of the area that contributes to light emission is protected, so deterioration of the light-emitting layer can be suppressed.

[0057] Figure 4 shows a part of the manufacturing process of the display device 1 of Embodiment 1. Figure 5 shows a part of the manufacturing process of the display device 1 of Embodiment 1 that is carried out after the manufacturing process of the display device 1 of Embodiment 1 shown in Figure 4. Figure 6 shows a part of the manufacturing process of the display device 1 of Embodiment 1 that is carried out after the manufacturing process of the display device 1 of Embodiment 1 shown in Figure 5. Figure 7 shows a part of the manufacturing process of the display device 1 of Embodiment 1 that is carried out after the manufacturing process of the display device 1 of Embodiment 1 shown in Figure 6.

[0058] If the display device 1 is equipped only with a first passivation film 12 as a passivation film, the manufacturing method of the display device 1 is a step of forming a plurality of lower electrodes 5 on a substrate 2 (step S1 shown in Figure 4), a step of forming a light-emitting element by patterning in which a functional layer including the lower electrodes 5 and an upper electrode 8 are stacked in this order from the substrate 2 side at positions that overlap with each of the plurality of lower electrodes 5 in a plan view (steps S3 to S14 shown in Figures 4 and 5), and a step of forming the light-emitting element by patterning (as shown in Figures 4 and 5) The process includes the steps of forming a first passivation film 12 that covers at least the upper electrode 8 of each of the multiple light-emitting elements and has first contact holes 12C1 to 12C6 located at positions that overlap with each of the upper electrodes 8 in a plan view (steps S15 to S18 shown in Figure 6), which are performed after steps S3 to S14 shown, and forming a conductive layer 13 that electrically connects each of the upper electrodes 8 through the first contact holes 12C1 to 12C6 (step S19 shown in Figure 7). In this embodiment, the case in which the display device 1 is equipped with a red light-emitting element 10R, a blue light-emitting element 10B, and a green light-emitting element 10G is described as an example, but the process is not limited to this, and the display device 1 may be equipped with multiple light-emitting elements that emit a specific color, for example. In this case, when the display device 1 is equipped with multiple light-emitting elements that emit a specific color, only the step of forming the light-emitting elements that emit a specific color by patterning is required. In this embodiment, if the display device 1 is equipped with a bank 4, the process of forming a bank 4 in contact with the lower electrodes 5 is included between the process of forming a plurality of lower electrodes 5 on the substrate 2 (S1 shown in Figure 4) and the process of forming a plurality of light-emitting elements by patterning (processes S3 to S14 shown in Figures 4 and 5).

[0059] If the display device 1 is equipped with only a first passivation film 12 as a passivation film, and is equipped with a red light-emitting element 10R, a blue light-emitting element 10B, and a green light-emitting element 10G, the method for manufacturing the display device 1 includes the steps of forming the red light-emitting element 10R by patterning, forming the blue light-emitting element 10B by patterning, and forming the green light-emitting element 10G by patterning.In other words, in the process of forming the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G by patterning (steps S3 to S14 shown in Figures 4 and 5), in a plan view, the lower electrode 5 (first lower electrode), the functional layer FCR (first functional layer) including the red light-emitting layer REM (first light-emitting layer), and the upper electrode 8 (first upper electrode) provided on the red light-emitting element 10R are arranged in this order from the substrate 2 side, at a position where they overlap with the lower electrode 5 (first lower electrode) provided on the red light-emitting element 10R, which is one of the electrodes of the plurality of lower electrodes 5. The process involves patterning a stacked red light-emitting element 10R (first light-emitting element) (steps S3 to S7 shown in Figure 4), and then, in a plan view, a blue light-emitting element that emits light of a different color from the red light-emitting layer REM (first light-emitting layer) is placed at a position where it overlaps with the lower electrode 5 (second lower electrode) provided on the blue light-emitting element 10B, which is one of the other electrodes among the multiple lower electrodes 5. The process involves patterning a blue light-emitting element 10B (second light-emitting element) by which a functional layer FCB (second functional layer) containing a light-emitting layer BEM (second light-emitting layer) and an upper electrode 8 (second upper electrode) provided on the blue light-emitting element 10B are stacked in this order from the substrate 2 side (steps S8 to S12 shown in Figure 4), and then patterning a plurality of blue light-emitting elements 10B (second light-emitting elements) (steps S8 to S12 shown in Figure 4), followed by the process of forming a green light-emitting element, which is a further subset of the electrodes among the plurality of lower electrodes 5 in a plan view. The process includes a step (S13 to S14 shown in Figure 4) of patterning a green light-emitting element 10G (third light-emitting element) in which the lower electrode 5 (third lower electrode) provided on 10G overlaps with a functional layer FCG (third functional layer) which includes a green light-emitting layer GEM (third light-emitting layer) that emits light of a different color from the red light-emitting layer REM (first light-emitting layer) and the blue light-emitting layer BEM (second light-emitting layer), and the upper electrode 8 (third upper electrode) provided on the green light-emitting element 10G are stacked in this order from the substrate 2 side.Then, in the step of forming the conductive layer 13 included in the manufacturing method of the display device 1 (step S19 shown in Figure 7), a conductive layer 13 is formed that electrically connects the upper electrode 8 (first upper electrode) provided on the red light-emitting element 10R, the upper electrode 8 (second upper electrode) provided on the blue light-emitting element 10B, and the upper electrode 8 (third upper electrode) provided on the green light-emitting element 10G, respectively, through their respective first contact holes 12C1 to 12C6.

[0060] As described above, the display device 1 may be provided with only the first passivation film 12 as a passivation film. However, since the deterioration of the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G can be further suppressed in each of the steps of forming the red light-emitting element 10R by patterning, the blue light-emitting element 10B, and the green light-emitting element 10G by patterning, in this embodiment, we will describe a case in which the display device 1 further includes, along with the first passivation film 12, a second passivation film 11R provided on the red light-emitting element 10R, a third passivation film 11B provided on the blue light-emitting element 10B, and a fourth passivation film 11G provided on the green light-emitting element 10G. Furthermore, in this embodiment, we will describe, as an example, the case in which the first lower charge transport layer 6HI of each of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G provided in the display device 1 is a common layer, and the second lower charge transport layer 6HT of each of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G provided in the display device 1 is also a common layer. However, we are not limited to this, and at least one of the first lower charge transport layer 6HI and the second lower charge transport layer 6HT may be formed of different materials for each of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G.

[0061] The manufacturing method of the display device 1 of this embodiment described above includes a step of forming a common lower charge transport layer, a first lower charge transport layer 6HI and a second lower charge transport layer 6HT, on the surface of the substrate 2 on which the multiple lower electrodes 5 are provided, which is performed between the step of forming a plurality of lower electrodes 5 on the substrate 2 (step S1 shown in Figure 4) and the step of forming a red light-emitting element 10R (first light-emitting element) by patterning (steps S3 to S7 shown in Figure 4).

[0062] Then, the process of forming the red light-emitting element 10R (first light-emitting element) by patterning (steps S3 to S7 shown in Figure 4) is the process of forming a first resist layer RE1 having a first aperture RE1K at a position that overlaps with the lower electrode 5 (first lower electrode) provided on the red light-emitting element 10R in a plan view on the second lower charge transport layer 6HT, which is the common lower charge transport layer (step S3 shown in Figure 4), and forming a red light-emitting layer REM on the first resist layer RE1 and the first aperture RE1K. Steps include: stacking a first light-emitting layer, an upper charge transport layer 7ET (first upper charge transport layer) provided on the red light-emitting element 10R, an upper electrode 8 (first upper electrode) provided on the red light-emitting element 10R, and a second passivation film 11R in this order from the substrate 2 side (step S4 shown in Figure 4); and forming a second resist layer RE2 on the second passivation film 11R at a position that overlaps with the lower electrode 5 (first lower electrode) in a plan view (step S5 shown in Figure 4). Then, by etching using the first resist layer RE1 and the second resist layer RE2 as masks, a red light-emitting element 10R (first light-emitting element) is formed, which consists of a lower electrode 5 (first lower electrode), a functional layer FCR (first functional layer) composed of a first lower charge transport layer 6HI, a second lower charge transport layer 6HT, a red light-emitting layer REM, and an upper charge transport layer 7ET, an upper electrode 8 (first upper electrode), and a second passivation film 11R, stacked in this order from the substrate 2 side. The process includes forming a child and leaving the common lower charge transport layers, the first lower charge transport layer 6HI and the second lower charge transport layer 6HT, at positions that overlap with the lower electrode 5 (second lower electrode) provided on the blue light-emitting element 10B and at positions that overlap with the lower electrode 5 (third lower electrode) provided on the green light-emitting element 10G in a plan view (step S6 shown in Figure 4), and peeling off the first resist layer RE1 and the second resist layer RE2 (step S7 shown in Figure 4).

[0063] Then, the process of forming the blue light-emitting element 10B (second light-emitting element) by patterning (steps S8 to S12 shown in Figure 5) includes the step of forming a third resist layer RE3 having a second aperture RE3K at a position that overlaps with the lower electrode 5 (second lower electrode) provided on the blue light-emitting element 10B (second light-emitting element) in a plan view (step S8 shown in Figure 5), the step of stacking a blue light-emitting layer BEM (second light-emitting layer), an upper charge transport layer 7ET (second upper charge transport layer) provided on the blue light-emitting element 10B, an upper electrode 8 (second upper electrode) provided on the blue light-emitting element 10B, and a third passivation film 11B in this order from the substrate 2 side (step S9 shown in Figure 5), and the step of forming a fourth resist layer RE4 on the third passivation film 11B at a position that overlaps with the lower electrode 5 (second lower electrode) in a plan view (Figure 5 The process includes the steps of: step S10 shown in Figure 5; etching using the third resist layer RE3 and the fourth resist layer RE4 as masks to form a blue light-emitting element 10B (second light-emitting element) in which a lower electrode 5 (second lower electrode), a functional layer FCB (second functional layer) consisting of a first lower charge transport layer 6HI, a second lower charge transport layer 6HT, a blue light-emitting layer BEM and an upper charge transport layer 7ET, an upper electrode 8 (second upper electrode), and a third passivation film 11B are stacked in this order from the substrate 2 side, and leaving the common lower charge transport layers, the first lower charge transport layer 6HI and the second lower charge transport layer 6HT, in a position that overlaps with the lower electrode 5 (third lower electrode) provided on the green light-emitting element 10G in a plan view (step S11 shown in Figure 5); and peeling off the third resist layer RE3 and the fourth resist layer RE4 (step S12 shown in Figure 5).

[0064] Then, the process of forming the green light-emitting element 10G (third light-emitting element) by patterning (steps S13 to S14 shown in Figure 5) is as follows: Step (S13 shown in Figure 5) of forming a fifth resist layer RE5 having a third aperture RE5K at a position that overlaps with the lower electrode 5 (third lower electrode) provided on the green light-emitting element 10G (third light-emitting element) in a plan view; Step (S13 shown in Figure 5) of stacking the green light-emitting element GEM (third light-emitting layer), the upper charge transport layer 7ET (third upper charge transport layer) provided on the green light-emitting element 10G, the upper electrode 8 (third upper electrode) provided on the green light-emitting element 10G, and the fourth passivation film 11G in this order from the substrate 2 side (not shown); and Step (S13 to S14 shown in Figure 5) of the green light-emitting element 11 The process includes: forming a sixth resist layer on G at a position that overlaps with the lower electrode 5 (third lower electrode) in a plan view (not shown); forming a green light-emitting element 10G (third light-emitting element) by etching using the fifth resist layer RE5 and the sixth resist layer as masks (not shown), thereby stacking the lower electrode 5 (third lower electrode), a functional layer FCG (third functional layer) which includes a green light-emitting layer GEM composed of a first lower charge transport layer 6HI, a second lower charge transport layer 6HT, a green light-emitting layer GEM, and an upper charge transport layer 7ET, an upper electrode 8 (third upper electrode), and a fourth passivation film 11G in this order from the substrate 2 side; and peeling off the fifth resist layer RE5 and the sixth resist layer (S14 step shown in Figure 5).

[0065] Then, in the step of forming the conductive layer 13 (step S19 shown in Figure 7), the upper electrode 8 (first upper electrode) provided on the red light-emitting element 10R, the upper electrode 8 (second upper electrode) provided on the blue light-emitting element 10B, and the upper electrode 8 (third upper electrode) provided on the green light-emitting element 10G are electrically connected via the respective first contact holes 12C1 to 12C6 shown in Figure 2, and the respective second contact holes 11RC1, 11RC2, 11BC1, 11BC2, 11GC1, and 11GC2 of the second passivation films 11R, third passivation film 11B, and fourth passivation film 11G, which are formed to overlap with the respective first contact holes 12C1 to 12C6 in a plan view.

[0066] In this embodiment, the case in which a red light-emitting element 10R, a blue light-emitting element 10B, and a green light-emitting element 10G are formed in this order by patterning has been described as an example, but the invention is not limited to this, and the order in which each color of light-emitting element is formed can be appropriately determined.

[0067] Furthermore, between the process of forming the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G by patterning (steps S3 to S14 shown in Figures 4 and 5) and the process of forming the conductive layer 13 (step S19 shown in Figure 7), a step of forming the first passivation film 12 (steps S15 to S18 shown in Figure 6) is performed.

[0068] The steps for forming the first passivation film 12 (steps S15 to S18 shown in Figure 6) include, for example, a step of depositing or coating the first passivation film 12 over the entire display area DA of the display device 1 (step S15 shown in Figure 6), a step of forming a seventh resist layer RE6 having fifth openings RE6K1 to RE6K6 provided corresponding to the positions where contact holes CH1 to CH6 are formed (step S16 shown in Figure 6), and etching the first passivation film 12 using the seventh resist layer RE6 as a mask. The process includes forming contact holes CH1 to CH6 by forming contact holes 12C1 to 12C6, and forming second contact holes 11RC1 and 11RC2 in the second passivation film 11R, second contact holes 11BC1 and 11BC2 in the third passivation film 11B, and second contact holes 11GC1 and 11GC2 in the fourth passivation film 11G (step S17 shown in Figure 6), and peeling off the seventh resist layer RE6 (step S18 shown in Figure 6).

[0069] Furthermore, the manufacturing method of the display device 1 preferably further includes, after the step of forming the conductive layer 13 (step S19 shown in Figure 7), a step of forming an eighth resist layer RE7 having a sixth aperture RE7K provided in a plan view at a position corresponding to the effective light-emitting regions of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G described above (step S20 shown in Figure 7), a step of removing the conductive layer 13 that overlaps with the effective light-emitting regions of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G in a plan view by etching using the eighth resist layer RE7 as a mask (step S21 shown in Figure 7), and a step of peeling off the eighth resist layer RE7 (step S22 shown in Figure 7). As described above, when the conductive layer 13 that overlaps with the effective light-emitting regions of the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G in a plan view is removed, that is, when the conductive layer 13 that overlaps with the opening 4K of the bank 4 shown by the dotted line in Figure 3 in a plan view is removed, the reflection and absorption of light from the light-emitting elements by the conductive layer 13 can be suppressed.

[0070] In this embodiment, in the step of forming the third resist layer RE3 (step S8 shown in Figure 5), it is preferable in a plan view that the second aperture RE3K is located inside the edge of the laminate of the first lower charge transport layer 6HI and the second lower charge transport layer 6HT, which are the common lower charge transport layers left over from the step of forming the red light-emitting element 10R (first light-emitting element) by patterning (steps S3 to S7 shown in Figure 4). Similarly, in the step of forming the fifth resist layer RE5 (step S13 shown in Figure 5), it is preferable in a plan view that the third aperture RE5K is located inside the edge of the laminate of the first lower charge transport layer 6HI and the second lower charge transport layer 6HT, which are the common lower charge transport layers left over from the step of forming the blue light-emitting element 10B (second light-emitting element) by patterning (steps S8 to S12 shown in Figure 5). As described above, after the step (not shown) of forming a green light-emitting element 10G (third light-emitting element) in which the lower electrode 5 (third lower electrode), the first lower charge transport layer 6HI, the second lower charge transport layer 6HT, the green light-emitting layer GEM composed of the green light-emitting layer GEM and the upper charge transport layer 7ET are stacked in this order from the substrate 2 side, an upper electrode 8 (third upper electrode), and a fourth passivation film 11G remains between the red light-emitting element 10R (first light-emitting element) and the blue light-emitting element 10B (second light-emitting element), between the blue light-emitting element 10B (second light-emitting element) and the green light-emitting element 10G (third light-emitting element), and between the green light-emitting element 10G (third light-emitting element) and the red light-emitting element 10R (first light-emitting element), a lower film 14 composed of the first lower charge transport layer 6HI' and the second lower charge transport layer 6HT', which are part of the common lower charge transport layer, remains between the red light-emitting element 10R (first light-emitting element) and the blue light-emitting element 10B (second light-emitting element), between the blue light-emitting element 10B (second light-emitting element) and the green light-emitting element 10G (third light-emitting element) and the red light-emitting element 10R (first light-emitting element). In this embodiment, the case in which the lower film 14 remains was described as an example, but the invention is not limited to this, and the lower film 14 may be made to disappear by adjusting the position of the openings formed in the resist layer.

[0071] Furthermore, if the manufacturing method of the display device 1 includes, as in this embodiment, steps S20, S21, and S22 shown in Figure 7 after the step of forming the conductive layer 13 (step S19 shown in Figure 7), then preferably a step of forming a sealing layer 24 (not shown) that at least covers the display area DA on which the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G are provided, after the step of peeling off the eighth resist layer RE7 (step S22 shown in Figure 7). Note that the step of forming the sealing layer 24 may include a step of forming a first sealing film 21, a step of forming a second sealing film 22 on the first sealing film 21, and a step of forming a third sealing film 23 on the second sealing film 22.

[0072] Furthermore, as shown in Figure 1, if the display device 1 is equipped with terminal portions TER for wiring to drive the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, the terminal portions TER may be formed together with the conductive layer 13 in the step of forming the conductive layer 13 (step S19 shown in Figure 7) included in the manufacturing method of the display device 1. With this manufacturing method of the display device 1, the terminal portions TER and the conductive layer 13 can be formed in a single step, thus reducing the number of steps.

[0073] [Embodiment 2] Figure 8 is a plan view showing an enlarged view of one pixel PIX in the display area DA of the display device 1a of Embodiment 2. Figure 9 is a cross-sectional view along the line X-X' in Figure 8, showing the schematic configuration of the display area DA of the display device 1a of Embodiment 2 shown in Figure 8. Figure 10 is a cross-sectional view along the line Y-Y' in Figure 8, showing the schematic configuration of the display area DA of the display device 1a of Embodiment 2 shown in Figure 8. Figure 11 is a cross-sectional view along the line Z-Z' in Figure 8, showing the schematic configuration of the display area DA of the display device 1a of Embodiment 2 shown in Figure 8.

[0074] As shown in Figures 8, 9, 10, and 11, the bank 4 provided in the display device 1a has an opening 4K, indicated by a dotted line in Figure 8, in each of the red light-emitting element 10R, blue light-emitting element 10B, and green light-emitting element 10G. As shown in Figures 9, 10, and 11, the lower electrode 5 is in contact with the functional layer FCR including the red light-emitting layer REM, the functional layer FCB including the blue light-emitting layer BEM, and the functional layer FCG including the green light-emitting layer GEM, in the portion of the opening 4K of the bank 4, so that the portion of the opening 4K of the bank 4 becomes the effective light-emitting region of the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, respectively. In this embodiment, as shown in Figure 8, contact holes CH1 to CH3 are provided on each of the red light-emitting element 10R, the blue light-emitting element 10B, and the green light-emitting element 10G, within the above-mentioned effective light-emitting region, which is different from the display device 1 of Embodiment 1 described above, in that contact holes CH1 to CH6 are provided outside the effective light-emitting region. Note that the other configurations of the display device 1a are the same as those of the display device 1 in Embodiment 1 described above, so their explanation will be omitted here.

[0075] In Embodiment 1, the shape of the conductive layer 13 in one pixel PIX within the display area DA of the display device 1 of Embodiment 1 was explained based on Figure 3, but the shape of the conductive layer 13 in the entire display area DA of the display device 1 of Embodiment 1 was not explained. Therefore, based on Figures 12 and 13, the shape of the conductive layer 13 in the display area DA of the display device 1 of Embodiment 1 will also be explained while describing the conductive layers 13, 15, 15a, and 15b provided in the display areas DA of the display devices 1a and 1b of Embodiment 2.

[0076] Figure 12 shows an example of conductive layers 13 and 15 provided in the display area DA of the display device 1a of Embodiment 2 shown in Figure 8.

[0077] As shown in Figure 12, the display area DA of the display device 1a comprises a plurality of pixels PIX, each including a red subpixel RSP containing a red light-emitting element 10R (first light-emitting element), a blue subpixel BSP containing a blue light-emitting element 10B (second light-emitting element), and a green subpixel GSP containing a green light-emitting element 10G (third light-emitting element). The display area DA of the display device 1a is provided with a grid-shaped conductive layer including a conductive layer 13 and a conductive layer 15. The first wiring, which corresponds to the conductive layer 13, overlaps with the respective contact holes CH1 to CH3, including a first contact hole located at a position overlapping with the upper electrode 8 of the red light-emitting element 10R (first light-emitting element), the upper electrode 8 of the blue light-emitting element 10B (second light-emitting element), and the upper electrode 8 of the green light-emitting element 10G (third light-emitting element), in a plan view, and is formed in a shape that crosses the pixels PIX. In this embodiment, as shown in Figure 12, the first wiring corresponding to the conductive layer 13 is formed in a shape that crosses the pixels PIX at the shortest distance, i.e., a straight line shape, but is not limited to this. The second wiring corresponding to the conductive layer 15 is electrically connected to the first wiring corresponding to the conductive layer 13, and in a plan view, it overlaps with the region between multiple pixels PIX and is formed along a second direction D2 that intersects with the first direction D1, which is the extending direction of the first wiring corresponding to the conductive layer 13. In the display area DA of the display device 1 described above in Embodiment 1, a grid-shaped conductive layer including the conductive layer 13 and the conductive layer 15 may also be provided.

[0078] Figure 13 shows an example of conductive layers 13, 15a, and 15b provided in the display area DA of the display device 1b, which is a modified example of the display device of Embodiment 2 shown in Figure 8.

[0079] As shown in Figure 13, the display area DA of the display device 1b comprises a plurality of pixels PIX, each including a red subpixel RSP containing a red light-emitting element 10R (first light-emitting element), a blue subpixel BSP containing a blue light-emitting element 10B (second light-emitting element), and a green subpixel GSP containing a green light-emitting element 10G (third light-emitting element). The display area DA of the display device 1b is provided with a substantially grid-shaped conductive layer, which includes a conductive layer 13, a conductive layer 15a, and a conductive layer 15b. The conductive layer 15b extends along a first direction D1, the conductive layer 15a extends along a second direction D2, and the conductive layer 13 extends from the conductive layer 15b along the second direction D2. The trunk wiring corresponding to the conductive layer 15a and conductive layer 15b is provided so as to overlap with the area between the plurality of pixels PIX in a plan view. Each of the multiple branch wirings corresponding to the conductive layer 13 extends from the conductive layer 15b, which is the main wiring, so as to overlap with the respective contact holes, including the first contact hole, which is located in a position that overlaps with the upper electrode 8 of the red light-emitting element 10R (first light-emitting element), the upper electrode 8 of the blue light-emitting element 10B (second light-emitting element), and the upper electrode 8 of the green light-emitting element 10G (third light-emitting element) in a plan view. In the display area DA of the display device 1 described above in Embodiment 1, a substantially grid-shaped conductive layer including the conductive layer 13, the conductive layer 15a, and the conductive layer 15b may also be provided.

[0080] As described above, in this embodiment, the case in which a grid-shaped conductive layer or a substantially grid-shaped conductive layer is provided in the display area DA of the display devices 1a and 1b has been described as an example, but the invention is not limited to this, and for example, the conductive layer may be provided over the entire display area of ​​the display device. In the case where the conductive layer is provided over the entire display area of ​​the display device and the light-emitting element provided in the display device is of the top-emission type, it is preferable that the conductive layer is made of a material that transmits visible light, for example, a transparent metal oxide (for example, indium tin oxide, indium zinc oxide, indium gallium zinc oxide, etc.).

[0081] [Additional Notes] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0082] This disclosure can be used for display devices and methods for manufacturing display devices.

[0083] 1, 1a, 1b Display device 2 Substrate 3 Thin-film transistor layer 4 Bank 4K Bank opening 5 Lower electrode 6HI, 6HI' First lower charge transport layer 6HT, 6HT' Second lower charge transport layer 7ET Upper charge transport layer 8 Upper electrode 10R Red light-emitting element 10B Blue light-emitting element 10G Green light-emitting element 11R Second passivation film 11B Third passivation film 11G Fourth passivation film 11RC1, 11RC2 Second contact hole 11BC1, 11BC2 Second contact hole 11GC1, 11GC2 Second contact hole 12 First passivation film 12C1-12C6 First contact hole 13, 15, 15a, 15b Conductive layer 14 Lower film 21 First sealing film 22 Second sealing film 23 Third sealing film 24 Sealing layer REM Red light-emitting layer BEM Blue light-emitting layer GEM Green light-emitting layer FCR Functional layer including red light-emitting layer FCB Functional layer including blue light-emitting layer FCG Functional layer including green light-emitting layer CH1 to CH6 Contact holes RE1 First resist layer RE1K First aperture RE2 Second resist layer RE3 Third resist layer RE3K Second aperture RE4 Fourth resist layer RE5 Fifth resist layer RE5K Third aperture RE6 Seventh resist layer RE6K1 to RE6K6 Fifth aperture RE7 Eighth resist layer RE7K Sixth aperture PIX Pixel RSP Red subpixel GSP Green subpixel BSP Blue subpixelDA Display area NDA Frame area TER Terminal section D1 First direction D2 Second direction

Claims

1. A display device comprising: a substrate; a plurality of light-emitting elements formed on the substrate by stacking a lower electrode, a functional layer including a light-emitting layer, and an upper electrode in this order from the substrate side; a first passivation film provided so as to cover at least the upper electrode of each of the plurality of light-emitting elements and having a first contact hole provided at a position that overlaps with the upper electrode in a plan view; and a conductive layer that electrically connects the upper electrodes through the first contact holes.

2. The display device according to claim 1, wherein the plurality of light-emitting elements include a first light-emitting element having a first light-emitting layer as the light-emitting layer, a second light-emitting element having a second light-emitting layer that emits a different color from the first light-emitting layer as the light-emitting layer, and a third light-emitting element having a third light-emitting layer that emits a different color from the first light-emitting layer and the second light-emitting layer as the light-emitting layer.

3. The device includes: a second passivation film provided between the upper electrode of the first light-emitting element and the first passivation film so as to be in contact with both the upper electrode of the first light-emitting element and the first passivation film; a third passivation film provided between the upper electrode of the second light-emitting element and the first passivation film so as to be in contact with both the upper electrode of the second light-emitting element and the first passivation film; and a fourth passivation film provided between the upper electrode of the third light-emitting element and the first passivation film so as to be in contact with both the upper electrode of the third light-emitting element and the first passivation film, wherein each of the second passivation film, the third passivation film, and the fourth passivation film has a second contact hole formed in a position that overlaps with the respective first contact holes provided in the first passivation film in a plan view. The display device according to claim 2, wherein the conductive layer electrically connects each of the upper electrodes via the respective first contact holes and the respective second contact holes.

4. The display device according to any one of claims 1 to 3, wherein the first passivation film is also formed between each of the plurality of light-emitting elements.

5. The display device according to any one of claims 1 to 3, wherein the first passivation film is also formed between each of the plurality of light-emitting elements so as to cover the side walls of each of the plurality of light-emitting elements.

6. The display device according to any one of claims 1 to 5, comprising a bank provided so as to be in contact with at least a portion of the end of the lower electrode, wherein a portion of the first passivation film formed between each of the plurality of light-emitting elements overlaps with the bank in a plan view.

7. The display device according to any one of claims 1 to 6, wherein the functional layer including the light-emitting layer is configured by stacking the lower charge transport layer, the light-emitting layer, and the upper charge transport layer in this order from the substrate side.

8. The display device according to claim 7, wherein a lower film made of the same material as the lower charge transport layer is provided between each of the plurality of light-emitting elements.

9. The display device according to claim 8, wherein the lower film is covered with the first passivation film and the conductive layer.

10. The display device according to claim 8 or 9, comprising a bank provided so as to be in contact with at least a portion of the end of the lower electrode, wherein the lower membrane is provided on the bank.

11. The display device according to any one of claims 7 to 10, wherein the lower electrode is an anode, the lower charge transport layer is at least one of a hole injection layer and a hole transport layer, the upper charge transport layer is at least one of an electron transport layer and an electron injection layer, and the upper electrode is a cathode.

12. The display device according to any one of claims 7 to 10, wherein the lower electrode is a cathode, the lower charge transport layer is at least one of an electron injection layer and an electron transport layer, the upper charge transport layer is at least one of a hole transport layer and a hole injection layer, and the upper electrode is an anode.

13. The display device according to any one of claims 1 to 12, wherein the lower electrode is an electrode that reflects visible light, and the upper electrode is an electrode that transmits visible light.

14. The display device according to claim 13, wherein the conductive layer is made of a material that transmits visible light.

15. The display device according to claim 14, wherein the conductive layer is provided so as to overlap the entire display area on which the plurality of light-emitting elements are provided in a plan view.

16. The display device according to any one of claims 1 to 12, wherein the lower electrode is an electrode that transmits visible light, and the upper electrode is an electrode that reflects visible light.

17. The display device according to claim 13 or 16, wherein the conductive layer is a metal wiring.

18. The display device according to any one of claims 1 to 14, 16, or 17, wherein the conductive layer is provided so as to overlap with a part of the display area on which the plurality of light-emitting elements are provided in a plan view.

19. The display device according to claim 18, wherein the plurality of light-emitting elements include a first light-emitting element having a first light-emitting layer as the light-emitting layer, a second light-emitting element having a second light-emitting layer that emits a different color from the first light-emitting layer as the light-emitting layer, and a third light-emitting element having a third light-emitting layer that emits a different color from the first light-emitting layer and the second light-emitting layer, and comprises a pixel having a first subpixel having the first light-emitting element, a second subpixel having the second light-emitting element, and a third subpixel having the third light-emitting element, and the conductive layer overlaps with the respective first contact holes provided in a plan view at positions overlapping with the upper electrodes of the respective first light-emitting elements, the first light-emitting element, and the third light-emitting element, and includes a portion that crosses the pixel.

20. The display device according to claim 18, wherein the plurality of light-emitting elements include a first light-emitting element having a first light-emitting layer as the light-emitting layer, a second light-emitting element having a second light-emitting layer that emits a different color from the first light-emitting layer as the light-emitting layer, and a third light-emitting element having a third light-emitting layer that emits a different color from the first light-emitting layer and the second light-emitting layer as the light-emitting layer, and comprises a plurality of pixels, each comprising a first subpixel having the first light-emitting element, a second subpixel having the second light-emitting element, and a third subpixel having the third light-emitting element, and the conductive layer includes a main wiring and a plurality of branch wirings electrically connected to the main wiring, the main wiring is provided so as to overlap with the region between the plurality of pixels in a plan view, and each of the plurality of branch wirings extends from the main wiring so as to overlap with the respective first contact holes provided at positions that overlap with the upper electrodes of the first light-emitting element, the second light-emitting element, and the third light-emitting element, respectively, in a plan view.

21. The display device according to claim 18, wherein the plurality of light-emitting elements include a first light-emitting element having a first light-emitting layer as the light-emitting layer, a second light-emitting element having a second light-emitting layer that emits a different color from the first light-emitting layer as the light-emitting layer, and a third light-emitting element having a third light-emitting layer that emits a different color from the first light-emitting layer and the second light-emitting layer, and comprises a plurality of pixels, each including a first subpixel having the first light-emitting element, a second subpixel having the second light-emitting element, and a third subpixel having the third light-emitting element, and the conductive layer includes a first wiring and a second wiring electrically connected to the first wiring, the first wiring is formed in a shape that overlaps with the respective first contact holes provided in a position that overlaps with the upper electrodes of the respective first light-emitting elements, the first light-emitting element, and the third light-emitting element, in a plan view, and crosses the pixels, and the second wiring is formed in a shape that overlaps with the region between the plurality of pixels in a plan view, and intersects with a second direction that crosses a first direction which is the extending direction of the first wiring.

22. The display device according to any one of claims 1 to 21, further comprising terminal portions for wiring to drive each of the plurality of light-emitting elements, wherein the terminal portions are formed of the same material as the conductive layer.

23. A method for manufacturing a display device, comprising: a step of forming a plurality of lower electrodes on a substrate; a step of patterning a plurality of light-emitting elements, in which the lower electrodes, a functional layer including a light-emitting layer, and an upper electrode are stacked in this order from the substrate side at positions that overlap with each of the plurality of lower electrodes in a plan view; a step of forming a first passivation film, performed after the step of patterning the plurality of light-emitting elements, which covers at least the upper electrode of each of the plurality of light-emitting elements and has a first contact hole provided at a position that overlaps with each of the upper electrodes in a plan view; and a step of forming a conductive layer that electrically connects each of the upper electrodes through the first contact holes.

24. The process of forming the plurality of light-emitting elements by patterning includes: forming a first light-emitting element by patterning in which, in a plan view, the first lower electrode, a first functional layer including a first light-emitting layer as the functional layer, and a first upper electrode as the upper electrode are stacked in this order from the substrate side at a position overlapping with a first lower electrode which is a part of the plurality of lower electrodes; and forming a second light-emitting element by patterning in which, after the process of forming the plurality of first light-emitting elements by patterning, the second lower electrode, a second functional layer including a second light-emitting layer which emits light of a different color from the first light-emitting layer as the functional layer, and a second upper electrode as the upper electrode are stacked in this order from the substrate side at a position overlapping with a second lower electrode which is another part of the plurality of lower electrodes in a plan view; A method for manufacturing a display device according to claim 23, comprising the step of forming the plurality of second light-emitting elements by patterning, wherein, in a plan view, the third lower electrode is stacked in this order from the substrate side at a position where it overlaps with the third lower electrode, which is a further portion of the plurality of lower electrodes, the third functional layer includes a third light-emitting layer that emits light of a different color from the first light-emitting layer and the second light-emitting layer as the functional layer, and the third upper electrode is the upper electrode, and in the step of forming the conductive layer, the conductive layer is formed to electrically connect the first upper electrode, the second upper electrode and the third upper electrode through the respective first contact holes.

25. The process includes a step of forming a common lower charge transport layer on the surface of the substrate on which the plurality of lower electrodes are provided, which is performed between the step of forming a plurality of lower electrodes on the substrate and the step of forming the first light-emitting element by patterning, wherein the step of forming the first light-emitting element by patterning includes a step of forming a first resist layer on the common lower charge transport layer having a first opening in a position that overlaps with the first lower electrodes in a plan view, a step of stacking the first light-emitting layer, a first upper charge transport layer, a first upper electrode, and a second passivation film on the first resist layer and the first opening in this order from the substrate side, and a step of forming a second resist layer on the second passivation film in a position that overlaps with the first lower electrodes in a plan view, The process of forming the second light-emitting element by patterning includes the steps of: etching the first resist layer and the second resist layer as masks to form the first light-emitting element in which the first lower electrode, the first functional layer, the first upper electrode, and the second passivation film are stacked in this order from the substrate side, and leaving the common lower charge transport layer at a position overlapping with the second lower electrode and a position overlapping with the third lower electrode in a plan view, and peeling off the first resist layer and the second resist layer, and the process of forming the second light-emitting element by patterning includes the steps of: forming a third resist layer having a second opening at a position overlapping with the second lower electrode in a plan view; stacking the second light-emitting layer, the second upper charge transport layer, the second upper electrode, and the third passivation film on the third resist layer and the second opening in this order from the substrate side; and forming a fourth resist layer on the third passivation film at a position overlapping with the second lower electrode in a plan view. The process of forming the third light-emitting element by patterning includes the steps of: etching using the third resist layer and the fourth resist layer as a mask to form the second light-emitting element in which the second lower electrode, the second functional layer, the second upper electrode, and the third passivation film are stacked in this order from the substrate side, leaving the common lower charge transport layer in a position that overlaps with the third lower electrode in a plan view; and peeling off the third resist layer and the fourth resist layer.The process includes: forming a fifth resist layer having a third opening in a position overlapping with the third lower electrode in a plan view; stacking the third light-emitting layer, the third upper charge transport layer, the third upper electrode, and the fourth passivation film on the fifth resist layer and the third opening in this order from the substrate side; forming a sixth resist layer on the fourth passivation film in a position overlapping with the third lower electrode in a plan view; forming the third light-emitting element by etching using the fifth resist layer and the sixth resist layer as masks, wherein the third lower electrode, the third functional layer, the third upper electrode, and the fourth passivation film are stacked in this order from the substrate side; and peeling off the fifth resist layer and the sixth resist layer. The method for manufacturing a display device according to claim 24, wherein in the step of forming the conductive layer, the conductive layer is formed to electrically connect the first upper electrode, the second upper electrode, and the third upper electrode via the respective first contact holes and the respective second contact holes of the second passivation film, the third passivation film, and the fourth passivation film, which are formed so as to overlap with the respective first contact holes in a plan view.

26. The method for manufacturing a display device according to claim 25, wherein in the step of forming the third resist layer, the second opening is formed in a plan view so as to be located inside the end of the common lower charge transport layer left in the step of forming the first light-emitting element by patterning, in the step of forming the fifth resist layer, the third opening is formed in a plan view so as to be located inside the end of the common lower charge transport layer left in the step of forming the second light-emitting element by patterning, and after the step of forming the third light-emitting element, a portion of the common lower charge transport layer remains between the first light-emitting element and the second light-emitting element, between the second light-emitting element and the third light-emitting element, and between the third light-emitting element and the first light-emitting element.

27. A method for manufacturing a display device according to any one of claims 23 to 26, comprising the step of forming a bank in contact with the lower electrodes between the step of forming a plurality of lower electrodes on the substrate and the step of forming the plurality of light-emitting elements by patterning.

28. A method for manufacturing a display device according to any one of claims 23 to 27, comprising the step of forming a sealing layer that covers at least the display area on which the plurality of light-emitting elements are provided, performed after the step of forming the conductive layer.

29. A method for manufacturing a display device according to any one of claims 23 to 28, comprising terminal portions for wiring to drive each of the plurality of light-emitting elements, wherein the terminal portions are formed together with the conductive layer in the step of forming the conductive layer.

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