Display device and display device production method

Abstract

The present invention provides a display device in which a high definition is easily achieved. The present invention also provides a display device that has a high display quality and a high definition. The present invention additionally provides a display device that has a high contrast. The present invention further provides a display device that is highly reliable. Provided is a display device that has a first light-emitting element, a second light-emitting element, and a partition wall that is located between the first light-emitting element and the second light-emitting element. The first light-emitting element has a first pixel electrode, a first EL layer on the first pixel electrode, and an upper electrode. The second light-emitting element has a second pixel electrode, a second EL layer on the second pixel electrode, and the upper electrode. The upper electrode covers the upper surface of the first EL layer and the upper surface of the second EL layer, and is in contact with side surfaces of the partition wall.

Description

Display device and method for manufacturing a display device

[0001] One aspect of the present invention relates to a display device. Another aspect of the present invention relates to a method for manufacturing a display device.

[0002] It should be noted that one aspect of the present invention is not limited to the above-mentioned technical field. Examples of technical fields of one aspect of the present invention disclosed herein include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, input devices, input / output devices, methods for driving them, or methods for manufacturing them. A semiconductor device refers to any device that can function by utilizing semiconductor properties.

[0003] In recent years, there has been a growing demand for higher resolution display panels. Devices requiring high-resolution display panels include, for example, smartphones, tablet devices, and notebook computers. Furthermore, stationary display devices such as television sets and monitors are also required to have higher resolutions. In addition, devices that require the highest level of resolution include, for example, devices for virtual reality (VR) or augmented reality (AR).

[0004] Furthermore, typical examples of display devices applicable to display panels include liquid crystal displays, organic EL (Electroluminescence) elements, light-emitting devices equipped with light-emitting elements such as light-emitting diodes (LEDs), and electronic paper that displays information using electrophoretic methods.

[0005] For example, the basic structure of an organic EL element consists of a layer containing a light-emitting organic compound sandwiched between a pair of electrodes. By applying a voltage to this element, light can be obtained from the light-emitting organic compound. Because a display device using such an organic EL element does not require a backlight, which is necessary for liquid crystal displays and the like, it is possible to realize a thin, lightweight, high-contrast, and low-power display device. For example, an example of a display device using an organic EL element is described in Patent Document 1.

[0006] Furthermore, while a method using a metal mask is known for fabricating different organic EL elements, it has limitations in terms of aperture ratio, resolution, and substrate size. Patent document 2 describes a method for fabricating different organic EL elements using photolithography without using a metal mask.

[0007] Japanese Patent Publication No. 2002-324673, International Publication No. 2023 / 285907

[0008] One aspect of the present invention aims to provide a display device that is easily made high-resolution, and a method for manufacturing the same. Another aspect of the present invention aims to provide a display device that combines high display quality and high resolution. Another aspect of the present invention aims to provide a display device with high contrast. Another aspect of the present invention aims to provide a highly reliable display device.

[0009] One aspect of the present invention aims to provide a display device having a novel configuration, or a method for manufacturing a display device. Another aspect of the present invention aims to provide a method for manufacturing the above-mentioned display device with a high yield. Another aspect of the present invention aims to mitigate at least one of the problems of the prior art.

[0010] One aspect of the present invention is a display device comprising a first light-emitting element, a second light-emitting element, and a partition wall located between the first and second light-emitting elements, wherein the first light-emitting element comprises a first pixel electrode, a first EL layer on the first pixel electrode, and an upper electrode, and the second light-emitting element comprises a second pixel electrode, a second EL layer on the second pixel electrode, and an upper electrode, the upper electrode covering the upper surface of the first EL layer and the upper surface of the second EL layer and in contact with the side surface of the partition wall.

[0011] In the above embodiment, the first EL layer preferably comprises a first layer and a second layer on the first layer, wherein the first layer includes a hole injection layer, the second layer includes a first luminescent compound, the edge of the first layer is located inward from the edge of the second layer, and the second EL layer preferably includes a second luminescent compound.

[0012] In the above embodiment, the first EL layer comprises a first layer, a second layer on the first layer, and a charge generation layer located between the first and second layers, wherein the first layer contains a first luminescent compound, the second layer contains a second luminescent compound, the edge of the charge generation layer is located inward from the edge of the second layer, and the second EL layer preferably contains a third luminescent compound.

[0013] Furthermore, in the above embodiment, it is preferable that the first luminescent compound and the second luminescent compound are compounds that emit light of the same color.

[0014] Furthermore, in the above embodiment, it is preferable that the first luminescent compound and the second luminescent compound are compounds that emit light of different colors.

[0015] Furthermore, in the above embodiment, it is preferable that the partition wall has an inverse tapered shape in cross-sectional view and is electrically conductive.

[0016] In the above embodiment, it is preferable that the device has a first insulating layer, the first insulating layer is located between the first pixel electrode and the second pixel electrode, the partition wall is in contact with the upper surface of the first insulating layer, and the angle between the contact surface of the partition wall and the first insulating layer and the side surface is 95 degrees or more and 150 degrees or less.

[0017] Preferably, the pixel has a first insulating layer, the ends of the first and second pixel electrodes are covered by the first insulating layer, the partition wall is located on the first insulating layer, the first EL layer is in contact with the upper surface of the first pixel electrode and the upper surface of the first insulating layer, the second EL layer is in contact with the upper surface of the second pixel electrode and the upper surface of the first insulating layer, and the upper electrode is in contact with the upper surface of the first insulating layer.

[0018] In the above embodiment, it is preferable that the partition wall contains oxygen and indium.

[0019] Furthermore, in the above embodiment, it is preferable to have a transistor, the transistor being located below the first pixel electrode and connected to the first pixel electrode.

[0020] Furthermore, in the above embodiment, it is preferable that the transistor is located below the first pixel electrode and connected to the first pixel electrode, and that the semiconductor layer in which the channel is formed contains a metal oxide.

[0021] Alternatively, in one aspect of the present invention, a first pixel electrode and a second pixel electrode are formed on a substrate; a first conductive film is formed on the first pixel electrode and the second pixel electrode; a first mask is formed on the first conductive film; a partition wall is formed between the first pixel electrode and the second pixel electrode by wet etching using the first mask; a first film is formed on the first pixel electrode, the second pixel electrode, and the partition wall using a vapor deposition method, wherein the formation of the first film is carried out such that the material flies at a first angle with respect to the perpendicular direction of the surface to be formed on the substrate; a second film is formed on the first film using a vapor deposition method, wherein the formation of the second film is carried out with respect to the perpendicular direction The method for manufacturing a display device involves the following steps: the material is flown at a second angle, a second mask is formed on the second film, the second mask is formed to overlap with the first pixel electrode, a first EL layer is formed by removing a part of the second film and a part of the first film using the second mask, a second EL layer is formed on the second pixel electrode, an upper electrode is formed using a vapor deposition method on the first EL layer, on the second EL layer, and in contact with the side surface of the partition wall, the formation of the upper electrode is carried out so that the material is flown at a third angle with respect to the vertical direction, the first angle is 0 degrees or more, the second angle is greater than the first angle, and the third angle is greater than the second angle.

[0022] Furthermore, in the above embodiment, it is preferable to form a third film using a vapor deposition method in which the material flies at a first angle with respect to the vertical direction, form a fourth film using a vapor deposition method in which the material flies at a second angle with respect to the vertical direction, and then form a second EL layer by processing the third and fourth films.

[0023] According to one aspect of the present invention, it is possible to provide a display device that is easily made high-resolution, and a method for manufacturing the same. Alternatively, it is possible to provide a display device that combines high display quality and high resolution. Alternatively, it is possible to provide a display device with high contrast. Alternatively, it is possible to provide a highly reliable display device.

[0024] Furthermore, according to one aspect of the present invention, a display device having a novel configuration, or a method for manufacturing a display device, can be provided. Alternatively, a method for manufacturing the above-mentioned display device with a high yield can be provided. According to one aspect of the present invention, at least one of the problems of the prior art can be mitigated.

[0025] Furthermore, the description of these effects does not preclude the existence of other effects. Moreover, one aspect of the present invention does not necessarily have to possess all of these effects. Other effects can be extracted from the description in the specification, drawings, claims, etc.

[0026] Figures 1A and 1B show examples of the configuration of a display device. Figures 2A, 2B, and 2C show examples of the configuration of a display device. Figure 3 shows an example of the configuration of a display device. Figures 4A, 4B, 4C, 4D, 4E, and 4F illustrate examples of methods for manufacturing a display device. Figures 5A and 5B illustrate examples of methods for manufacturing a display device. Figures 6A, 6B, and 6C illustrate examples of methods for manufacturing a display device. Figures 7A, 7B, and 7C illustrate examples of methods for manufacturing a display device. Figure 8 illustrates an example of a method for manufacturing a display device. Figures 9A and 9B illustrate examples of methods for manufacturing a display device. Figures 10A, 10B, 10C, 10D, and 10E illustrate examples of methods for manufacturing a display device. Figures 11A and 11B show examples of the configuration of a display device manufacturing apparatus. Figure 12 shows an example of the configuration of a display device. Figure 13 shows an example of the configuration of a display device. Figures 14A and 14B show examples of display device configurations. Figures 15A and 15B show examples of display device configurations. Figure 16 shows an example of display device configuration. Figure 17 shows an example of display device configuration. Figure 18 shows an example of display device configuration. Figures 19A, 19B, 19C, 19D, 19E, and 19F show examples of light-emitting device configurations. Figures 20A, 20B, and 20C show examples of light-emitting device configurations. Figures 21A, 21B, 21C, and 21D show examples of electronic device configurations. Figures 22A, 22B, 22C, 22D, 22E, and 22F show examples of electronic device configurations. Figures 23A, 23B, 23C, 23D, 23E, 23F, and 23G show examples of electronic device configurations. Figures 24A and 24B show examples of electronic device configurations. Figure 24C shows how electronic devices are being used.

[0027] The embodiments will be described below with reference to the drawings. However, it will be readily apparent to those skilled in the art that the embodiments can be implemented in many different ways, and their form and details can be modified in various ways without departing from the spirit and scope thereof. Accordingly, the present invention shall not be construed as being limited to the contents of the following embodiments.

[0028] In the structure of the invention described below, the same reference numerals are commonly used among different drawings for the same or resembling parts with the same functions, and repeated explanations thereof are omitted. Also, when referring to similar functions, the hatching patterns may be the same, and there may be no particular reference numerals attached.

[0029] In each of the drawings described in this specification, the sizes of each component, the thicknesses of layers, or regions may be exaggerated for clarity. Therefore, they are not necessarily limited to that scale.

[0030] The ordinal numbers such as "first", "second", etc. in this specification are attached to avoid confusion of components and do not numerically limit them.

[0031] In this specification, etc., "the upper surface shapes are approximately the same" means that at least a part of the contours overlap between the stacked layers. For example, it includes the case where the upper layer and the lower layer are processed by the same mask pattern or a part of them is processed by the same mask pattern. However, strictly speaking, the contours may not overlap exactly, and the upper layer may be located inside the lower layer or outside the lower layer. In this case, it may also be said that "the upper surface shapes are approximately the same".

[0032] In this specification, etc., the upper surface shape of a certain component refers to the contour shape of the component in its plan view. Also, the plan view means looking from the normal direction of the surface of the surface on which the component is formed or the support (e.g., substrate) on which the component is formed.

[0033] In the following, expressions indicating directions such as "upper" and "lower" are basically used in accordance with the directions in the drawings. However, for the purpose of facilitating explanations, etc., the directions indicated by "upper" or "lower" in the specification may not match the drawings. As an example, when explaining the stacking order (or formation order) of a laminate, etc., even if the surface (formed surface, support surface, adhesive surface, flat surface, etc.) on which the laminate is provided in the drawing is located above the laminate, the formed surface may be described as being below, and the laminate may be described as being above.

[0034] Also, in this specification and the like, the term "film" and the term "layer" can be mutually interchanged. For example, the term "insulating layer" may be mutually interchangeable with the term "insulating film".

[0035] Note that in this specification, the EL layer refers to a layer (also called a light-emitting layer) provided between a pair of electrodes of a light-emitting element and containing at least a light-emitting substance, or a laminate including the light-emitting layer.

[0036] Also, in this specification and the like, a display panel substrate to which a connector such as an FPC (Flexible Printed Circuit) or a TCP (Tape Carrier Package) is attached, or a substrate on which an IC is mounted by a COG (Chip On Glass) method or the like may be called a display panel module, a display module, or simply a display panel.

[0037] (Embodiment 1) In this embodiment, a configuration example of a display device according to an aspect of the present invention and an example of its manufacturing method will be described.

[0038] One aspect of the present invention is a display device having a light-emitting element (also referred to as a light-emitting device). The display device has at least two light-emitting elements that emit light of different colors. Each light-emitting element has a pair of electrodes and an EL layer therebetween. The light-emitting element is preferably an organic EL element (organic electroluminescence element). Two or more light-emitting elements that emit light of different colors each have an EL layer containing a different material. For example, by having three types of light-emitting elements that emit red (R), green (G), or blue (B) light respectively, a full-color display device can be realized.

[0039] Here, when differentiating between light-emitting elements of different emission colors by creating part or all of the EL layer, it is known that this is done by deposition using a shadow mask such as a metal mask. However, with this method, deviations from the design occur in the shape and position of island-like organic films due to various influences such as the precision of the metal mask, the misalignment between the metal mask and the substrate, the deflection of the metal mask, and the spreading of the contour of the deposited film due to vapor scattering, making it difficult to increase the resolution and aperture ratio of the display device. For this reason, measures have been taken to artificially increase the resolution (also called pixel density) by applying special pixel arrangement methods such as pentile arrangements.

[0040] One aspect of the present invention involves processing the EL layer into a fine pattern without using a shadow mask such as a metal mask. This makes it possible to realize a display device with high resolution and a high aperture ratio, which has been difficult to achieve until now. Furthermore, since the EL layer can be differentiated, it is possible to realize a display device with extremely vivid colors, high contrast, and high display quality.

[0041] One aspect of the present invention involves providing a partition wall between two adjacent light-emitting elements (a first light-emitting element and a second light-emitting element) to physically divide the EL layer. The partition wall is a conductive structure with an inverse tapered shape on its sides. The partition wall can also be described as having a shape in which its upper part protrudes laterally more than its lower part. The partition wall is formed so as to be located between two adjacent pixel electrodes. Alternatively, the partition wall is provided so as to surround one pixel electrode. When the EL layer of the first light-emitting element is deposited, a step is created by the partition wall.

[0042] In this specification, "step breakage" refers to the phenomenon in which a layer, film, electrode, etc., is divided due to the shape of the surface on which it is formed (for example, a step or other difference in height).

[0043] Subsequently, a resist mask is formed to cover the target pixel electrode and a portion of the partition wall, and the EL layer located in the area not covered by the resist mask is removed by etching. At this time, it is preferable to form a mask layer after the deposition of the EL layer, and to etch this film together with the etching of the EL layer to form a mask layer on the EL layer. The mask layer can function as a hard mask. It is also preferable to leave the mask layer after the resist mask is removed. This allows the EL layer of the first light-emitting element to be protected in the subsequent etching process. The mask layer is sometimes called a sacrificial layer.

[0044] Next, the EL layer of the second light-emitting element is formed. Then, a resist mask is formed to cover the target pixel electrode and a portion of the partition wall, and the EL layer located in the area not covered by the resist mask is removed by etching. When etching the EL layer of the second light-emitting element, it is preferable that the mask layer remains on the EL layer of the first light-emitting element. This protects the EL layer of the first light-emitting element during the etching of the EL layer of the second light-emitting element.

[0045] Next, the EL layer of the third light-emitting element is formed using the same process as for forming the EL layer of the second light-emitting element.

[0046] After forming the EL layer in each light-emitting element using the above process, the upper electrode is formed by covering the EL layer and the partition wall. At this time, the upper electrode is formed by a film formation method that provides higher step coverage than the EL layer. This makes it possible to have a configuration in which a part of the upper electrode covers the edge of the EL layer and is in contact with a part of the partition wall.

[0047] This results in the formation of a light-emitting element in a region surrounded by partitions, which includes pixel electrodes, island-shaped EL layers, and upper electrodes in contact with the partitions. The partitions in contact with the upper electrodes can also function as wiring for supplying potential to the upper electrodes.

[0048] By using the method described above, it is possible to create different types of light-emitting elements using photolithography, which enables microfabrication, without using a metal mask. This makes it possible to manufacture display devices with extremely high resolution and a high aperture ratio.

[0049] While it is difficult to reduce the spacing between different colored EL layers to less than 10 μm using, for example, a metal mask formation method, the above method allows for narrowing the spacing to 3 μm or less, 2 μm or less, or even 1 μm or less. For example, by using an exposure apparatus for LSIs, the spacing can be narrowed to 500 nm or less, 200 nm or less, 100 nm or less, and even 50 nm or less. This significantly reduces the area of ​​the non-emitting region that may exist between two light-emitting elements, making it possible to approach an aperture ratio of 100%. For example, an aperture ratio of 50% or more, 60% or more, 70% or more, 80% or more, and even 90% or more, can be achieved, and even less than 100%.

[0050] Furthermore, the size of the EL layer itself can be made significantly smaller compared to when a metal mask is used. Also, for example, when a metal mask is used to create different EL layers, variations in thickness occur between the center and edges of the island-shaped EL layer, resulting in a smaller effective area usable as an emitting region relative to the total area of ​​the EL layer. On the other hand, with the above manufacturing method, island-shaped EL layers are formed by processing a film deposited to a uniform thickness, so the thickness can be made uniform, and even if the size of the EL layer is fine, almost the entire area can be used as an emitting region. Therefore, the above manufacturing method can achieve both high resolution and a high aperture ratio.

[0051] Thus, the above manufacturing method makes it possible to realize a display device that integrates fine light-emitting elements. As a result, a display device can be realized with a configuration in which each pixel has three colored light-emitting elements, and with a resolution of 500 ppi or more, 1000 ppi or more, 2000 ppi or more, 3000 ppi or more, 5000 ppi or more, and even 8000 ppi or more. Therefore, a display device with high resolution can be realized without applying special pixel arrangement methods such as the PenTile method to artificially increase resolution.

[0052] Below, we will explain more specific examples with reference to the diagrams.

[0053] [Configuration Example] Figure 1A shows a schematic top view of the display device 100. The display device 100 has multiple red light-emitting elements 110R, multiple green light-emitting elements 110G, and multiple blue light-emitting elements 110B.

[0054] The light-emitting elements 110R, 110G, and 110B are each arranged in a matrix. Figure 1A shows a so-called stripe arrangement, in which light-emitting elements of the same color are arranged in one direction. However, the arrangement method of the light-emitting elements is not limited to this, and other arrangement methods such as S-stripe arrangement, delta arrangement, zigzag arrangement may be applied, or a pentile arrangement may be used. Figure 1B shows an example in which an S-stripe arrangement is used.

[0055] It is preferable to use EL elements such as OLEDs (Organic Light Emitting Diodes) or QLEDs (Quantum-dot Light Emitting Diodes) as the light-emitting elements 110R, 110G, and 110B. Examples of light-emitting materials for EL elements include fluorescent materials, phosphorescent materials, and thermally activated delayed fluorescence (TADF) materials. Not only organic compounds but also inorganic compounds (such as quantum dot materials) can be used as light-emitting materials for EL elements.

[0056] In this embodiment, when describing matters common to components distinguished by letters or numbers attached to their reference numerals (such as the first EL layer 112R and the first EL layer 112G), the reference numerals (such as the first EL layer 112) may be used without further explanation.

[0057] Furthermore, partition walls 120 are provided between each light-emitting element 110. The partition walls 120 have a grid-like upper surface shape. It can also be said that the light-emitting elements 110 are provided in the region surrounded by the partition walls 120.

[0058] Figure 2A is a schematic cross-sectional view of the display device 100 corresponding to the cutting line B-A shown in Figure 1A. The display device 100 has a plurality of transistors 150, a light-emitting element 110R, a light-emitting element 110G, and a light-emitting element 110B.

[0059] A transistor 150 is provided on the substrate 101. The transistor 150 has a semiconductor layer 151 on which a channel is formed, an insulating layer 152 that functions as a gate insulating layer, a conductive layer 153 that functions as a gate electrode, and a pair of conductive layers 154 that are in contact with the semiconductor layer 151 and function as a source electrode and a drain electrode. The conductive layers 154 are provided on an insulating layer 131 that covers the semiconductor layer 151, the insulating layer 152, and the conductive layers 153, and are in contact with the semiconductor layer 151 at an opening provided in the insulating layer 131. In Figure 2A, the transistor 150 is provided below the pixel electrode 111.

[0060] It is preferable to use a metal oxide (also called an oxide semiconductor) that exhibits semiconductor properties as the semiconductor layer 151. As the oxide semiconductor, an oxide semiconductor such as indium oxide or In-Ga-Zn oxide (IGZO) can be used. Alternatively, the semiconductor layer of the transistor may have silicon. Examples of silicon include amorphous silicon and crystalline silicon (low-temperature polysilicon, single-crystal silicon, etc.).

[0061] In addition, metal oxides that can be used in the semiconductor layer 151 include tin oxide, zinc oxide, indium tin oxide, indium titanium oxide, indium gallium oxide, indium tungsten oxide, indium zinc oxide, indium gallium aluminum oxide, indium gallium tin oxide, gallium zinc oxide, aluminum zinc oxide, indium aluminum zinc oxide, indium tin zinc oxide, indium titanium zinc oxide, indium gallium zinc oxide, indium gallium tin zinc oxide, and indium gallium aluminum zinc oxide. Alternatively, silicon-containing indium tin oxide, gallium tin oxide, aluminum tin oxide, etc., can also be used.

[0062] In this example, transistor 150 is shown as a so-called top-gate type transistor, where the gate electrode is located on the upper side of the semiconductor layer, but it is not limited to this. For example, a bottom-gate type transistor, where the gate electrode is located below the semiconductor layer, can also be used.

[0063] An insulating layer 132 is provided covering the conductive layer 154 and the insulating layer 131, and light-emitting elements 110R, 110G, and 110B are provided on the insulating layer 132.

[0064] The light-emitting element 110R has a first EL layer 112R and a second EL layer 114R on the first EL layer 112R between the pixel electrode 111R and the upper electrode 115. The light-emitting element 110G has a first EL layer 112G and a second EL layer 114G on the first EL layer 112G between the pixel electrode 111G and the upper electrode 115. The light-emitting element 110B has a first EL layer 112B and a second EL layer 114B on the first EL layer 112B between the pixel electrode 111B and the upper electrode 115.

[0065] It is preferable that the upper electrodes 115 of the light-emitting elements 110R, 110G, and 110B are electrically connected to each other. In the configuration shown in Figure 2A, the upper electrodes 115 of the light-emitting elements 110R, 110G, and 110B are shared, and a continuous conductive layer covers the EL layers of the three light-emitting elements. The upper electrodes 115 can function as a common electrode used in common by multiple functional elements.

[0066] Each pixel electrode 111 is provided on an insulating layer 132 and is connected to a conductive layer 154 at an opening in the insulating layer 132. As a result, each pixel electrode 111 is connected to either the source electrode or the drain electrode of the transistor 150.

[0067] The first EL layer 112R of the light-emitting element 110R has a luminescent organic compound that emits at least red light. The first EL layer 112G of the light-emitting element 110G has a luminescent organic compound that emits at least green light. The first EL layer 112B of the light-emitting element 110B has a luminescent organic compound that emits at least blue light. Blue light has, for example, an emission peak in the wavelength range of 450 nm or more and less than 500 nm. Green light has, for example, an emission peak in the wavelength range of 500 nm or more and less than 600 nm. Red light has, for example, an emission peak in the wavelength range of 600 nm or more and less than 700 nm.

[0068] The first EL layer 112R, the first EL layer 112G, and the first EL layer 112B may each have, in addition to a layer containing a light-emitting organic compound (light-emitting layer), one or more of the following: an electron injection layer, an electron transport layer, an electron blocking layer, a hole injection layer, a hole transport layer, and a hole blocking layer. The second EL layer 114R, the second EL layer 114G, and the second EL layer 114B may each have one or more of the following: an electron injection layer, an electron transport layer, an electron blocking layer, a hole injection layer, a hole transport layer, and a hole blocking layer.

[0069] The stacked structure of the first EL layer 112R and the second EL layer 114R can function as an EL layer of the light-emitting element 110R. Furthermore, the stacked structure of the first EL layer 112G and the second EL layer 114G can function as an EL layer of the light-emitting element 110G. Additionally, the stacked structure of the first EL layer 112B and the second EL layer 114B can function as an EL layer of the light-emitting element 110B.

[0070] Each of the second EL layers 114R, 114G, and 114B may, for example, have an electron injection layer or a hole injection layer. Alternatively, each of the second EL layers 114R, 114G, and 114B may have an electron transport layer and an electron injection layer laminated together, or a hole transport layer and a hole injection layer laminated together.

[0071] The first EL layer 112R has a layer 112aR and a layer 112bR on top of layer 112aR. The first EL layer 112G has a layer 112aG and a layer 112bG on top of layer 112aG. The first EL layer 112B has a layer 112aB and a layer 112bB on top of layer 112aB. In the light-emitting element 110R, it is preferable that the end of layer 112aR is located inward from at least one of layer 112bR and the second EL layer 114R. This allows the side surface of layer 112aR to be covered with either layer 112bR or the second EL layer 114R, and a configuration can be made in which the upper electrode 115 and layer 112aR do not come into contact. If layer 112aR comes into contact with the upper electrode 115 on its side surface, a leakage current may occur between the highly conductive layer in layer 112aR and the upper electrode 115. Such leakage currents can cause malfunctions in the operation of the light-emitting element 110R. In particular, in a configuration where layer 112aR has a hole injection layer, it is preferable that layer 112aR does not come into contact with the upper electrode 115.

[0072] Similarly, in the light-emitting element 110G, it is preferable that the edge of layer 112aG is located inward of at least one of layer 112bG and the second EL layer 114G. This allows the side surface of layer 112aG to be covered by either layer 112bG or the second EL layer 114G. Furthermore, in the light-emitting element 110B, it is preferable that the edge of layer 112aB is located inward of at least one of layer 112bB and the second EL layer 114B. This allows the side surface of layer 112aB to be covered by either layer 112bB or the second EL layer 114B.

[0073] Hereafter, the symbols R, G, and B may be omitted in descriptions common to the first EL layer 112R, the first EL layer 112G, and the first EL layer 112B. Similarly, the symbols R, G, and B may be omitted in layers 112aR, 112aG, 112aB, etc.

[0074] Figure 2A shows an example configuration in which the side surface of layer 112a is covered by layer 112b.

[0075] Note that in Figure 2A and subsequent drawings, for the sake of clarity, layers 112aR, 112bR and the second EL layer 114R, 112aG, 112bG and the second EL layer 114G, and layers 112aB, 112bB and the second EL layer 114B are shown as separate layers, but the boundaries between each layer may be difficult to observe.

[0076] Layer 112a has at least a hole injection layer or an electron injection layer. Layer 112a can also be configured by stacking a hole injection layer and a hole transport layer, or by stacking an electron injection layer and an electron transport layer. Furthermore, layer 112a can also have an emissive layer.

[0077] As an example of the configuration, layer 112a has a hole injection layer, layer 112b has a hole transport layer, an emissive layer on the hole transport layer, and an electron transport layer on the emissive layer, and the second EL layer 114 has an electron injection layer.

[0078] A conductive film that is translucent (also called transparent) to visible light is used on either each pixel electrode 111 or the upper electrode 115, and a conductive film that is reflective is used on the other. By making each pixel electrode 111 translucent and the upper electrode 115 reflective, a bottom-emission type light-emitting element can be created. Conversely, by making each pixel electrode 111 reflective and the upper electrode 115 translucent, a top-emission type light-emitting element can be created. Furthermore, by making both each pixel electrode 111 and the upper electrode 115 translucent, a dual-emission type display device can also be created.

[0079] Furthermore, a protective layer 135 is provided to cover the upper electrode 115.

[0080] The protective layer 135 can be, for example, a single-layer structure or a multilayer structure including at least an inorganic insulating film. Examples of inorganic insulating films include oxide films or nitride films such as silicon oxide film, silicon oxide nitride film, silicon nitride film, silicon nitride film, aluminum oxide film, aluminum oxide nitride film, and hafnium oxide film. Alternatively, semiconductor materials such as indium gallium oxide and indium gallium zinc oxide may be used as the protective layer 135.

[0081] Furthermore, a laminated film of an inorganic insulating film and an organic insulating film can also be used as the protective layer 135. For example, it is preferable to have a configuration in which an organic insulating film is sandwiched between a pair of inorganic insulating films.

[0082] An insulating layer 133 is provided to cover the ends of each pixel electrode 111. The portion of the pixel electrode 111 that is not covered by the insulating layer 133 functions as the light-emitting region of the light-emitting element 110. The ends of the insulating layer 133 are preferably tapered. The insulating layer 133 may be omitted if it is not needed.

[0083] In this specification, an object is said to have a tapered end if the angle between the side surface of the object and the contact surface of the object to be formed (also called the taper angle) is greater than 0 degrees and less than 90 degrees, and the object has a cross-sectional shape in which the thickness increases continuously from the end. On the other hand, an object is said to have an inverse tapered shape if the angle between the side surface of the object and the contact surface of the object to be formed is greater than 90 degrees and less than 180 degrees.

[0084] The insulating layer 133 preferably contains an organic resin. By using an organic resin as the insulating layer 133, adhesion to the first EL layer 112 can be improved. In particular, when each EL layer is processed by etching, it is preferable to use an insulating layer 133 with high adhesion to each EL layer, as this reduces the problem of each EL layer peeling off after etching. By suppressing the peeling of the EL layers, the manufacturing yield can be improved.

[0085] Furthermore, by using an organic resin for the insulating layer 133, its surface can be made flat or gently curved. This improves the coverage of the film formed on the insulating layer 133.

[0086] Examples of materials that can be used for the insulating layer 133 include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimidoamide resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins.

[0087] Each first EL layer 112 has a region in contact with the upper surface of the pixel electrode 111 and a region in contact with the surface of the insulating layer 133. The ends of each first EL layer 112 are located on the insulating layer 133.

[0088] A partition wall 120 is provided on the insulating layer 133. The partition wall 120 is conductive and has an inverse tapered shape.

[0089] Figure 2B shows an enlarged view of the light-emitting element 110B, the light-emitting element 110G, the partition wall 120 located between them, and the vicinity thereof.

[0090] The ends of the first EL layer 112B and the first EL layer 112G are located on the insulating layer 133. The upper electrode 115 covers the end of the first EL layer 112B and is in contact with the upper surface of the insulating layer 133 and a part of the side surface of the partition wall 120. The upper electrode 115 also covers the end of the first EL layer 112G and is in contact with the upper surface of the insulating layer 133 and a part of the side surface of the partition wall 120.

[0091] As shown in Figure 2B, the partition wall 120 is provided with a portion of the first EL layer 112B and a portion of the first EL layer 112G, with their sides facing each other. The first EL layer 112B has a first portion located on the pixel electrode 111 and functioning as the EL layer of the light-emitting element, and a second portion located on the partition wall 120. In the configuration shown in Figure 2B, a portion of the first EL layer 112B is provided on the pixel electrode 111, and an organic layer is provided on the partition wall 120, which is the other portion of the first EL layer 112B. Similarly, a portion of the first EL layer 112G is provided on the pixel electrode 111, and an organic layer is provided on the partition wall 120, which is the other portion of the first EL layer 112G. Furthermore, the first EL layer 112B has other sides that do not face the first EL layer 112G, and these sides form a continuous surface with the partition wall 120 and are covered by the upper electrode 115. Furthermore, the first EL layer 112G has other sides that do not face the first EL layer 112B, and these sides form a continuous surface with the partition wall 120 and are covered by the upper electrode 115.

[0092] The upper electrode 115 covers the side surface of the partition wall 120 and the upper surface of the insulating layer 133.

[0093] It is preferable that the upper electrodes 115 of adjacent light-emitting elements (here, light-emitting elements 110B and 110G are shown as examples) are electrically connected to each other. In the configuration shown in Figures 2A and 2B, the upper electrodes 115 are shared between light-emitting elements 110B and 110G, and a continuous conductive layer covers the EL layers of the two light-emitting elements. However, a portion of the upper electrode 115 may be missing on the side of the partition wall 120. The upper electrode 115 may be separated into multiple parts due to the partial disappearance. Even in such a case, each of the separated portions of the upper electrode 115 can be electrically connected via the partition wall 120.

[0094] As shown in Figure 1A and other figures, the partition wall 120 is arranged in a grid pattern so as to weave between the light-emitting elements 110, and can therefore also function as wiring that supplies potential to the upper electrode 115 of each light-emitting element 110.

[0095] In Figure 2A above, the height of the partition wall 120 is depicted as being greater than its width, but in reality, the cross-sectional width may be greater than the height. Figure 2B and others show an example where the cross-sectional width of the partition wall 120 is greater than its height. Also, Figure 2B and others show an example where the width of the EL layer is wider than the width of the partition wall.

[0096] Preferably, the height of the partition wall 120 is greater than the thickness of the thickest of the first EL layer 112R, the first EL layer 112G, and the first EL layer 112B. If the first EL layer 112 is too thick, it may become difficult for the partition wall 120 to cause a step in the layer. The taper angle θ of the partition wall 120 can be greater than 90 degrees and less than 180 degrees. The closer the taper angle is to 90 degrees, the easier it is for the partition wall 120 and the upper electrode 115 to come into contact when the upper electrode 115 is formed, while the gap between the end of the first EL layer 112 and the partition wall 120 becomes smaller. The closer the taper angle is to 180 degrees, the easier it is for the first EL layer 112 to cause a step in the layer, while it becomes difficult to bring the upper electrode 115 and the partition wall 120 into contact. For this reason, the taper angle θ should be, for example, 95 degrees or more and 150 degrees or less, preferably 100 degrees or more and 135 degrees or less.

[0097] The partition wall 120 can be made of various conductive materials. For example, metals, alloys, oxide conductive materials, nitride conductive materials, etc., can be used. For example, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metallic materials, can be used.

[0098] Furthermore, an oxide conductive material such as indium tin oxide can be used as the partition wall 120. Other materials that can be used include indium oxide, indium zinc oxide, indium titanium oxide, indium gallium zinc oxide, indium tin zinc oxide, indium titanium zinc oxide, and indium gallium tin zinc oxide. Alternatively, indium tin oxide containing silicon can also be used. It is preferable that the oxide conductive material contains indium because this can enhance the conductivity of the material.

[0099] In one aspect of the present invention, since the EL layer can be manufactured separately between adjacent light-emitting elements, leakage current through the EL layer can be substantially eliminated compared to cases where the EL layers are in contact with each other or where a common EL layer is used. This prevents unintended light emission and enables the realization of a display device with high contrast and high display quality. Furthermore, in the first EL layer 112, the portion that functions as the EL layer of the light-emitting element 110 is located within a region surrounded by the partition wall 120 in a plan view. In addition, within the region surrounded by the partition wall 120, the first EL layer 112 is covered by the upper electrode 115 and the protective layer 135, preventing the diffusion of impurities such as moisture into the first EL layer 112 and enabling the realization of a highly reliable display device. Moreover, in this configuration, since the processing of the first EL layer 112 and other parts can be performed entirely by photolithography without using a metal mask, it is easier to achieve high resolution and high aperture ratio compared to cases where a metal mask is used.

[0100] The edges Q of the second EL layer 114 and layer 112bB are located closer to the side surface of the partition wall 120 than the edge P of layer 112aB. Figure 2B shows that edge P is aligned with the edge of the upper surface of the partition wall 120. When forming layers 112aB, 112bB, and the second EL layer 114 using vapor deposition, it is preferable to perform the deposition of layer 112aB so that the material flies from the deposition source perpendicular to, or approximately perpendicular to, the substrate surface. Furthermore, it is preferable to perform the deposition of layer 112bB and the second EL layer 114 so that the material flies from the deposition source to the side surface of the partition wall 120. For example, in Figure 2B, it is preferable to perform the deposition so that the material flies to the area below the side surface of the partition wall 120. Here, when we say that the material flies perpendicular to the substrate surface, or roughly perpendicular to it, we mean, for example, that the material flies in a direction of 75 degrees to 105 degrees relative to the substrate surface, preferably 80 degrees to 100 degrees, and more preferably 85 degrees to 95 degrees. By controlling the direction in which the material flies from the deposition source in this way, layers 112aB, 112bB, and the second EL layer 114 can be formed such that the end Q is located closer to the side surface of the partition wall 120 than the end P.

[0101] Figure 2A and others show an example in which the partition wall 120 is provided on the insulating layer 133, but the insulating layer 133 does not need to be provided. Figure 2C shows an example in which the insulating layer 133 is not provided. In Figure 2C, the partition wall 120 is provided in contact with the upper surface of the insulating layer 132, similar to the pixel electrode 111. Also, the ends of the first EL layer 112B and the ends of the first EL layer 112G are located on the insulating layer 132, and the upper electrode 115 is in contact with the insulating layer 132 and the partition wall 120.

[0102] As shown in Figure 3, a configuration in which multiple light-emitting units are stacked can also be used as the EL layer of the light-emitting element. A configuration in which multiple light-emitting units are connected in series via an intermediate layer containing a charge generation layer is sometimes called a tandem structure.

[0103] In Figure 3, the first EL layer 112B has a structure in which layers 112aB, 112bB, 112gB, and 112hB are stacked in that order. The first EL layer 112G has a structure in which layers 112aG, 112bG, 112gG, and 112hG are stacked in that order. The first EL layer 112R has a structure in which layers 112aR, 112bR, 112gR, and 112hR are stacked in that order.

[0104] Hereafter, the symbols R, G, and B may be omitted in layers 112gR, 112gG, 112gB, 112hR, 112hG, and 112hB.

[0105] Layer 112b includes a first light-emitting layer, layer 112g includes a charge-generating layer, and layer 112h includes a second light-emitting layer.

[0106] As an example, layer 112a has a hole injection layer, layer 112b has a hole transport layer, a first light-emitting layer, and an electron transport layer, layer 112g has a charge generation layer, layer 112h has a hole transport layer, a second light-emitting layer on the hole transport layer, and an electron transport layer on the second light-emitting layer, and the second EL layer 114 has an electron injection layer.

[0107] In this case, layer 112b may have an electron blocking layer between the hole transport layer and the light-emitting layer. Layer 112b may also have a hole blocking layer between the light-emitting layer and the electron transport layer. Layer 112h may also have an electron blocking layer between the hole transport layer and the light-emitting layer. Layer 112h may also have a hole blocking layer between the light-emitting layer and the electron transport layer.

[0108] Alternatively, as an example, layer 112a has a hole injection layer, layer 112b has a hole transport layer, a first light-emitting layer, and an electron transport layer, layer 112g has a charge generation layer, layer 112h has a hole transport layer and a second light-emitting layer on the hole transport layer, and the second EL layer 114 has an electron transport layer and an electron injection layer on the electron transport layer.

[0109] In this case, layer 112b may have an electron blocking layer between the hole transport layer and the light-emitting layer. Layer 112b may also have a hole blocking layer between the light-emitting layer and the electron transport layer. Layer 112h may also have an electron blocking layer between the hole transport layer and the light-emitting layer. Layer 112h may also have a hole blocking layer on the light-emitting layer.

[0110] Since the charge generation layer has high conductivity, it is preferable that the edge of layer 112g is located inward from layer 112h or the second EL layer 114, as shown in Figure 3. This reduces the leakage current between the charge generation layer of layer 112g and the upper electrode 115.

[0111] The first and second light-emitting layers may, for example, contain a light-emitting organic compound that emits light of the same color. Alternatively, the first and second light-emitting layers may also contain light-emitting organic compounds that emit light of different colors.

[0112] The above is an explanation of the example configuration.

[0113] [Example of Manufacturing Method] Below, an example of a manufacturing method for a display device according to one embodiment of the present invention will be described with reference to the drawings. Here, the display device 100 shown in the above configuration example will be used as an example. Figures 4A to 8 are schematic cross-sectional views of each step in the manufacturing method of the display device illustrated below.

[0114] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum deposition, pulsed laser deposition (PLD), and atomic layer deposition (ALD).

[0115] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) that constitute the display device can be formed by methods such as spin coating, dip coating, spray coating, inkjet printing, dispensing, screen printing, offset printing, doctor knife coating, slit coating, roll coating, curtain coating, and knife coating.

[0116] Sputtering methods include RF sputtering, which uses a high-frequency power supply for sputtering; DC sputtering, which uses a DC power supply; and pulsed DC sputtering, which changes the voltage applied to the electrodes in pulses. For film deposition using insulating targets, RF sputtering is preferable. DC sputtering is mainly used when depositing films using conductive targets. In addition to forming conductive films, DC sputtering can also be used to form insulating films by reactive sputtering using pulsed DC sputtering. Specifically, pulsed DC sputtering can be used when depositing compounds such as oxides, nitrides, and carbides using reactive sputtering.

[0117] CVD methods can be classified into plasma-enhanced CVD (PECVD), which utilizes plasma; thermal CVD (TCD), which utilizes heat; and photo-CVD, which utilizes light. Furthermore, depending on the source gas used, they can be divided into metal CVD (MCCVD) and metal-organic CVD (MOCVD).

[0118] Plasma CVD allows for the production of high-quality films at relatively low temperatures. Thermal CVD, on the other hand, does not use plasma, thus minimizing plasma damage to the workpiece. Furthermore, thermal CVD avoids plasma damage during film formation, resulting in films with fewer defects.

[0119] As ALD methods, thermal ALD, which carries out the reaction of the precursor and reactant using only thermal energy, and PEALD, which uses plasma-excited reactants, can be used.

[0120] Unlike sputtering, CVD and ALD are film deposition methods that are less affected by the shape of the workpiece and provide good step-level coverage. In particular, the ALD method is suitable for coating the surface of openings with high aspect ratios due to its excellent step-level coverage and excellent thickness uniformity. However, since the ALD method has a relatively slow deposition rate, it is sometimes preferable to use it in combination with other film deposition methods that have a faster deposition rate, such as the CVD method.

[0121] In the CVD method, films of any composition can be formed by changing the flow rate ratio of the raw material gases. For example, in the CVD method, by changing the flow rate ratio of the raw material gases while the film is being deposited, films with continuously changing compositions can be formed. When depositing films while changing the flow rate ratio of the raw material gases, the time required for film deposition can be shortened compared to depositing films using multiple deposition chambers, because time required for transport or pressure adjustment is eliminated. Therefore, it may be possible to increase the productivity of display devices.

[0122] In the ALD method, films of any composition can be deposited by using multiple different types of precursors. Alternatively, when multiple different types of precursors are introduced, films of any composition can be deposited by controlling the number of cycles for each precursor. Furthermore, similar to the CVD method, films with continuously changing compositions can be deposited.

[0123] Furthermore, the thin films constituting the display device can be processed using photolithography or other methods. Alternatively, the thin films may be processed by nanoimprint lithography, sandblasting, lift-off methods, etc. Island-like thin films may also be directly formed using a film deposition method with a shielding mask such as a metal mask. Induced self-assembly (DSA) methods may also be used.

[0124] There are two main methods of photolithography. One method involves forming a resist mask on the thin film to be processed, then processing the thin film by etching or other means, and removing the resist mask. The other method involves forming a photosensitive thin film, then exposing and developing it to process the thin film into the desired shape.

[0125] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or a mixture thereof. Other light sources such as ultraviolet light, KrF laser light, or ArF laser light can also be used. Exposure may also be performed using immersion lithography. Furthermore, extreme ultraviolet (EUV) light or X-rays may be used as the light source for exposure. An electron beam can also be used instead of the light source for exposure. Using extreme ultraviolet light, X-rays, or an electron beam is preferable because it enables extremely fine processing. Note that a photomask is not required when exposure is performed by scanning a beam such as the above-mentioned light or an electron beam.

[0126] Thin films can be etched using methods such as dry etching, wet etching, and sandblasting. Dry etching allows for isotropic or anisotropic etching by controlling the conditions. Wet etching allows for isotropic etching.

[0127] First, a substrate 101 is prepared, and transistors 150, insulating layer 131, insulating layer 132, etc. are formed. Next, a conductive film is deposited on the insulating layer 132, and unnecessary parts are removed by etching to form pixel electrodes 111R, pixel electrode 111G, and pixel electrode 111B.

[0128] As the substrate 101, a substrate having at least enough heat resistance to withstand subsequent heat treatment can be used. For example, a glass substrate, quartz substrate, sapphire substrate, ceramic substrate, or organic resin substrate, a single-crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or a SOI substrate can be used.

[0129] When using a conductive film that is reflective to visible light as each pixel electrode 111, it is preferable to use a material (for example, silver or aluminum) that has the highest possible reflectivity across the entire wavelength range of visible light. This not only improves the light extraction efficiency of the light-emitting element but also enhances color reproduction.

[0130] Next, an insulating layer 133 is formed by covering the ends of each pixel electrode 111. An organic insulating film or an inorganic insulating film can be used as the insulating layer 133. It is preferable that the ends of the insulating layer 133 be tapered in order to improve the step coverage of the subsequent EL film. In particular, when using an organic insulating film, it is preferable to use a photosensitive material because it is easier to control the shape of the ends depending on the exposure and development conditions.

[0131] Next, a conductive film 120f, which will later become the partition wall 120, is formed. It is preferable to use a material for the conductive film 120f that allows for a large selectivity ratio between the etching rate and each pixel electrode 111. It is preferable to use different conductive materials for the conductive film 120f and the layer located at the top of the pixel electrode 111. Alternatively, a film that functions as an etching stopper may be formed before the conductive film 120f, and this film located on the pixel electrode 111 may be removed after etching of the conductive film 120f. In that case, the same conductive material can be used for the pixel electrode 111 and the conductive film 120f.

[0132] Next, a resist mask 198M is formed on the conductive film 120f (Figure 4A). Subsequently, the portion of the conductive film 120f not covered by the resist mask 198M is removed by etching to form a partition wall 120 (Figure 4B). Next, the resist mask 198M is removed. Note that in the drawings from Figure 4B onward, the structure of the layers below the insulating layer 132 may be omitted from the diagrams.

[0133] The conductive film 120f can be etched by isotropic etching. For example, wet etching or isotropic dry etching can be used. By processing the conductive film 120f so that etching proceeds faster at the bottom than at the top, a partition wall 120 having an inverse tapered shape can be formed.

[0134] For example, by selecting materials such that the adhesion between the conductive film 120f and the insulating layer 133 is lower than the adhesion between the conductive film 120f and the resist mask 198M, the etching rate at the bottom is improved compared to the top, and a reverse tapered partition wall 120 can be formed. For example, if a conductive oxide such as indium tin oxide is used for the conductive film 120f, an organic material with low adhesion to indium tin oxide (e.g., acrylic resin) can be used for the insulating layer 133.

[0135] The etching of the conductive film 120f will be explained using Figures 4C to 4F.

[0136] As shown in Figure 4C, the conductive film 120f is processed to a width approximately equal to that of the resist mask 198M. Note that in Figure 4C, the conductive film 120f is etched slightly inside the width of the resist mask 198M. For example, when isotropic etching is used, etching may proceed to an area inside the width of the resist mask 198M.

[0137] As shown in Figure 4D, if the adhesion between the insulating layer 133 and the conductive film 120f is low, etching may gradually progress from the edges of the conductive film 120f, starting from the surface in contact with the insulating layer 133 (the area enclosed by the dashed line). In particular, when wet etching is used, this type of etching is likely to occur because the etching solution can penetrate into interfaces with low adhesion.

[0138] As shown in Figure 4E, further etching can form a partition wall 120 having an inverse taper shape with a taper angle θ.

[0139] Furthermore, as shown in Figure 4F, the angle on the side of the partition wall 120 closer to the top surface of the partition wall 120 (indicated as angle θ2 in Figure 4F) may differ from the angle on the side closer to the insulating layer 133 (indicated as angle θ1 in Figure 4F). For example, angle θ1 may be greater than 90 degrees and less than 180 degrees, while angle θ2 may be 90 degrees or less.

[0140] As described above, by selecting a material with low adhesion to the conductive film 120f as the insulating layer 133, a partition wall 120 having an inverse tapered shape can be formed.

[0141] When an organic insulating layer is used as the insulating layer 133, it is preferable that the adhesion between the conductive film 120f and the insulating layer 133 is lower than, for example, the adhesion between the inorganic insulating layer and the conductive film 120f.

[0142] The adhesion between the insulating layer 133 and the conductive film 120f is preferably lower than, for example, the adhesion between silicon oxide and the conductive film 120f.

[0143] Adhesion can be verified, for example, using a peel test.

[0144] Next, a film 112aBf, which will become layer 112aB, is formed on each pixel electrode 111 and partition wall 120 (Figure 5A). The arrows in Figure 5A show an example of the flight direction of the film-forming material when the film-forming material is launched from the deposition source 299 using the deposition method. At this time, the film 112aBf is stepped by the partition wall 120, and is formed between the two regions of the partition wall 120 and on top of the partition wall 120. The film 112aBf can be formed using, for example, vacuum deposition, sputtering, or both.

[0145] The method for forming the film 112aBf will be explained using Figures 9A and 9B. Note that the structure of the layers below the insulating layer 132 is omitted in Figures 9A and 9B. It is preferable to form the film 112aBf using a highly anisotropic film formation method. That is, as shown in Figure 9B, the film is formed such that the angle β that the film-forming material 121 makes with the substrate surface in the direction of flight is perpendicular or approximately perpendicular to the upper surface of the substrate 101. This allows for step-cutting by the partition wall 120, as shown in Figure 9B. At this time, it is also preferable that sufficient space is secured between the film 112aBf and the partition wall 120 for the upper electrode 115 to fit into.

[0146] Next, films 112bBf and 114Bf are formed on film 112aBf and on the partition wall 120 (Figure 5B). At this time, films 112bBf and 114Bf are stepped by the partition wall 120 and formed between the two regions of the partition wall 120 and on top of the partition wall 120, respectively. Film 112bBf is the film that becomes layer 112bB, and film 114Bf is the film that becomes the second EL layer 114B. Films 112bBf and 114Bf can be formed using, for example, vacuum deposition, sputtering, or both.

[0147] It is preferable that films 112bBf and 114Bf are formed so as to cover the sides of film 112aBf. On the other hand, it is preferable that films 112bBf and 114Bf are formed so as not to cover the sides of the partition wall 120. Therefore, it is preferable that the film formation method used for films 112bBf and 114Bf has lower anisotropy than the film formation method used for film 112aBf and higher anisotropy than the film formation method used for the upper electrode 115. The film formation method used for the upper electrode 115 will be described later.

[0148] Next, an insulating film 199Bf is deposited. Subsequently, a resist mask 198B is formed on the insulating film 199Bf (Figure 6A).

[0149] The insulating layer 199B can function as a hard mask. Furthermore, the insulating layer 199B has the function of protecting the first EL layer 112B. The insulating layer 199B may be referred to as a mask layer, sacrificial layer, etc. By providing the insulating film 199Bf between the resist mask 198B and the film 112bBf, film loss and damage to the layer 112bB during the subsequent resist mask removal process can be suppressed.

[0150] Furthermore, when the film 112bBf is exposed to the atmosphere after its formation, the insulating film 199Bf is provided before exposure, so the film 112bBf is covered by the insulating film 199Bf and is not exposed. Therefore, degradation due to reactions between the layer 112bB and oxygen or moisture can be suppressed.

[0151] It is preferable to use a film that can be removed by wet etching or dry etching for the insulating film 199Bf.

[0152] The insulating film 199Bf is preferably formed using a method that minimizes damage to the film that will become the first EL layer 112B. For example, ALD or vacuum deposition is preferred over sputtering.

[0153] As the insulating film 199Bf, one or more types can be used from among metal films, alloy films, metal or metal compound films, semiconductor films, organic insulating films, and inorganic insulating films. Furthermore, two or more selected from these can be used in a laminated configuration.

[0154] As the insulating film 199Bf, for example, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing such metal materials, can be used. In particular, it is preferable to use a low melting point material such as aluminum or silver. Using a metal material capable of shielding ultraviolet rays for the insulating film 199Bf is preferable because it can suppress irradiation of the film that becomes the first EL layer 112B with ultraviolet rays during pattern exposure, thereby suppressing the deterioration of the film that becomes the first EL layer 112B.

[0155] Furthermore, as the insulating film 199Bf, for example, metals or metallic compounds such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and silicon-containing indium tin oxide can be used.

[0156] Furthermore, in the above metal or metallic compound, element M (where M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) may be used instead of gallium.

[0157] Furthermore, it is preferable to use semiconductor materials such as silicon or germanium as the insulating film 199Bf because they have high compatibility with semiconductor manufacturing processes. Alternatively, compounds containing the above semiconductor materials can be used.

[0158] Furthermore, various inorganic insulating films can be used as the insulating film 199Bf. In particular, oxide insulating films are preferred because they have higher adhesion to the film that becomes the first EL layer 112B compared to nitride insulating films.

[0159] By using the highly covering ALD method for forming the insulating film 199Bf, an insulating layer 199 with few pinholes and excellent protective function for the EL layer can be formed. Furthermore, by using the highly covering ALD method for forming the insulating film 199Bf, the side walls of the partition wall 120 can be well coated.

[0160] For the insulating film 199Bf, aluminum oxide produced by the ALD method is preferred, for example.

[0161] It is preferable to use a different material for the insulating film 199Bf than for the partition wall 120. Specifically, for example, it is preferable to select materials for the insulating film 199Bf and the partition wall 120 so that, during etching when the insulating film 199Bf is removed in a later process, film thinning of the partition wall 120 does not occur.

[0162] For the partition wall 120, an indium-containing oxide is preferred, and for the insulating film 199Bf, aluminum oxide produced by the ALD method is preferred.

[0163] Next, a portion of the insulating film 199Bf is removed using the resist mask 198B to form the insulating layer 199B. After that, the resist mask 198B is removed.

[0164] By using wet etching in the processing of the insulating film 199Bf, damage to the film that will become the first EL layer 112B during processing can be reduced compared to when dry etching is used. When using wet etching, for example, an alkaline aqueous solution such as a developer or an aqueous solution of tetramethylammonium hydroxide (TMAH) can be used. Alternatively, an acidic aqueous solution such as dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof can be used. It is preferable to perform the processing of the insulating film 199Bf by wet etching using an aqueous solution containing phosphoric acid and hydrofluoric acid (preferably an aqueous solution containing phosphoric acid and hydrofluoric acid but not nitric acid). By performing wet etching using an aqueous solution containing phosphoric acid and hydrofluoric acid (preferably an aqueous solution containing phosphoric acid and hydrofluoric acid but not nitric acid), the occurrence of dark spots and shrinkage of the display area can be suppressed, making it possible to provide a display device with good characteristics even for ultra-high-definition display devices.

[0165] Furthermore, when dry etching is used in processing the insulating film 199Bf, the degradation of the film that becomes the first EL layer 112B can be suppressed by not using an oxygen-containing gas as the etching gas.

[0166] The resist mask 198B can be removed, for example, by ashing using oxygen plasma.

[0167] Next, using the insulating layer 199B as a mask, a portion of film 114Bf, a portion of film 112bBf, and a portion of film 112aBf are removed, respectively, to form layers 112aB, 112bB, and the second EL layer 114B on the pixel electrode 111B (Figure 6B).

[0168] Furthermore, taking into account positional misalignment during patterning, it is preferable to form the resist mask 198B so as to overlap a portion of the upper surface of the partition wall 120. This ensures that films 112aBf, 112bBf, and 114Bf remain on the partition wall 120.

[0169] The films 114Bf, 112bBf, and 112aBf are preferably processed by anisotropic etching. Anisotropic dry etching is particularly preferred. Alternatively, wet etching may be used.

[0170] When using dry etching, by not using a gas containing oxygen as the etching gas, deterioration of the film 114Bf, the film 112bBf, and the film 112aBf can be suppressed.

[0171] Further, a gas containing oxygen may be used as the etching gas. By the etching gas containing oxygen, the etching rate can be increased. Therefore, etching can be performed under low-power conditions while maintaining the etching rate at a sufficient speed. For this reason, damage to a part of the film 112bBf and the film 112aBf can be suppressed. Furthermore, problems such as adhesion of reaction products generated during etching can be suppressed.

[0172] When using dry etching, for example, H ３ , ２ , ２ , ６ , ３ , ４ , ,

[0172] , ８ , ２ ,

[0175] , ４ , ,

[0173] ,

[0174] , , CF ４ , C ４ F ８ , SF ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ or a gas containing one or more of the Group 18 elements such as He, Ar, etc. is preferably used as the etching gas. Or, it is preferable to use one or more of these and a gas containing oxygen as the etching gas. Or, oxygen gas may be used as the etching gas.

[0173] Subsequently, a film 112aGf that becomes the layer 112aG is formed on the second EL layer 114B, on the pixel electrode 111G, on the pixel electrode 111R, and on the partition wall 120 (FIG. 6C). At this time, the film 112aGf is stepped by the partition wall 120 and is formed between two regions of the partition wall 120 and on the partition wall 120, respectively.

[0174] Subsequently, the film 112bGf and the film 114Gf are formed on the film 112aGf. At this time, the film 112bGf and the film 114Gf are stepped by the partition wall 120 and are formed between two regions of the partition wall 120 and on the partition wall 120, respectively.

[0175] Next, an insulating film 199Gf is formed. Then, a resist mask 198G is formed on the insulating film 199Gf (Figure 6C). Next, an insulating layer 199G, a second EL layer 114G, layer 112bG, and layer 112aG are formed (Figure 7A). The methods for forming films 112aGf, 112bGf, and 114Gf can be found by referring to the methods for forming films 112aBf, 112bBf, and 114Bf. Also, the methods for forming the second EL layer 114G, layer 112bG, and layer 112aG can be found by referring to the methods for forming the second EL layer 114B, layer 112bB, and layer 112aB.

[0176] Next, a film to become layer 112aR, a film to become layer 112bR, and a film to become the second EL layer 114R are formed on the second EL layer 114B, the second EL layer 114G, the pixel electrode 111R, and the partition wall 120, respectively. At this time, the film to become layer 112aR, the film to become layer 112bR, and the film to become the second EL layer 114R are each stepped off by the partition wall 120, and are formed between the two regions of the partition wall 120 and on top of the partition wall 120, respectively.

[0177] Next, an insulating film that will become the insulating layer 199R is formed. Then, a resist mask is formed on the insulating film that will become the insulating layer 199R. Next, the insulating layer 199R, the second EL layer 114R, layer 112bR, and layer 112aR are formed (Figure 7B). The methods for forming the film that will become layer 112aR, the film that will become layer 112bR, and the film that will become the second EL layer 114R can be found by referring to the methods for forming film 112aBf, film 112bBf, and film 114Bf, respectively. Also, the methods for forming the second EL layer 114R, layer 112bR, and layer 112aR can be found by referring to the methods for forming the second EL layer 114B, layer 112bB, and layer 112aB.

[0178] Next, insulating layers 199B, 199G, and 199R are removed (Figure 7C). The etching of insulating layers 199B, 199G, and 199R is performed by wet etching. By using wet etching, damage to the first EL layer 112B, first EL layer 112G, and first EL layer 112R can be reduced compared to using dry etching. Wet etching can be performed using, for example, an alkaline solution or an acidic solution. It is preferable to use an aqueous solution so that the first EL layer 112B, first EL layer 112G, and first EL layer 112R do not dissolve.

[0179] Next, the upper electrode 115 is formed (Figure 8). At this time, it is preferable that the upper electrode 115 is formed so as to cover the edges of the second EL layer 114 and layer 112b and to be in contact with at least a part of the side surface of the partition wall 120. The upper electrode 115 can be formed using one or more of the following methods: vacuum deposition, sputtering, and CVD.

[0180] The upper electrode 115 is preferably formed by a film deposition method that has even lower anisotropy than that of layer 112b and the second EL layer 114. It is preferable to use a film deposition method such that the flight direction of the film deposition material for the upper electrode 115 has components not only perpendicular to the upper surface of the substrate but also obliquely. For example, a film deposition method with low anisotropy can be achieved by reducing the distance between the deposition source (or sputtering target) and the substrate, using multiple deposition sources (or sputtering targets), or increasing the area of ​​the deposition source (or sputtering target).

[0181] Furthermore, as shown in Figure 10A, a film deposition apparatus can be used that has a mechanism for launching the film deposition material 122 from an oblique direction relative to the upper surface of the substrate 101 and rotating the substrate 101 on a rotation axis 125. In this case, as shown in Figure 10E, the angle β that the launching direction of the film deposition material makes with the substrate surface is less than 90 degrees. By making the angle β less than 90 degrees, the upper electrode 115 can also be deposited on the side surface of the partition wall 120 which has an inverse tapered shape. In Figure 10A, an example is shown in which the rotation axis 125 passes through the center of the substrate 101, but it may pass anywhere on the substrate 101, or the rotation axis 125 may be located off-center from the substrate 101. Also, the rotation axis 125 does not have to be perpendicular to the substrate surface of the substrate 101.

[0182] Furthermore, as shown in Figure 10B, a film deposition apparatus may be used that has a mechanism in which the substrate 101 rotates (oscillates) on a rotation axis 125 parallel to the substrate surface. In this case, the flight direction of the film deposition material 122 can be perpendicular to the rotation axis 125. Note that in Figures 10A and 10B, the structure of the layers below the insulating layer 132 is omitted.

[0183] By using a film deposition apparatus having the mechanisms shown in Figures 10A and 10B, as shown in Figure 10C, the film deposition process of the upper electrode 115 can include a period during which the deposition material 122 flies from an oblique direction relative to the substrate surface of the substrate 101, and a period during which it flies from an oblique direction opposite to that, as shown in Figure 10D. Therefore, as shown in Figure 10E, the upper electrode 115 can be deposited on the side surface of the partition wall 120 which has an inverse tapered shape, and the upper electrode 115 can be deposited on both the side surface shown on the left and the side surface shown on the right in the figure. Note that in Figure 10E, the second EL layer 114 is omitted for the sake of simplifying the drawing.

[0184] In addition, the above example shows a case where the substrate 101 moves, but the configuration may also be such that only the deposition source moves, or both the substrate 101 and the deposition source move.

[0185] Furthermore, in the formation of the second EL layer 114 and layer 112b, the angle β between the flight direction of the film-forming material and the substrate surface is, for example, smaller than the angle used for forming layer 112a and larger than the angle used for forming the upper electrode 115. Also, in the formation of the second EL layer 114 and layer 112b, it is preferable that the angle between the flight direction of the film-forming material and the direction perpendicular to the surface of the substrate to be formed is larger than the angle used for forming layer 112a and smaller than the angle used for forming the upper electrode 115.

[0186] Next, a protective layer 135 is formed to cover the upper electrode 115. The protective layer 135 is preferably formed by a film deposition method that provides high step coverage, and is preferably formed by CVD or ALD. The ALD method is particularly preferred because it causes less damage to the layer to be formed.

[0187] For example, an aluminum oxide film can be formed as the protective layer 135 by the ALD method. In this case, it is preferable to use trimethylaluminum, triethylaluminum, triisobutylaluminum, dimethylaluminum hydride, tris(dimethylamino)aluminum, tris(diethylamino)aluminum, or aluminum trichloride as the aluminum precursor. Furthermore, as the oxidizing agent, for example, ozone (O) ３ ), oxygen (O ２ ), water (H ２ O), Nitrogen dioxide (NO) ２ ), nitrous oxide (N ２ O), hydrogen peroxide (H ２ O ２ ) and others can be used, and two or more of these may be used.

[0188] Furthermore, the protective layer 135 may be a laminated structure of a film deposited by the ALD method and a film deposited by a film deposition method other than the ALD method (e.g., CVD method, sputtering method, etc.). While the ALD method has extremely high step coverage, its deposition rate is relatively slow compared to other film deposition methods. Therefore, by first depositing a film with very few defects using the ALD method, and then forming a thick insulating film using the CVD method or the like, the time required for the deposition process of the protective layer 135 can be shortened.

[0189] The display device 100 can be manufactured through the above process.

[0190] [Example of a film deposition apparatus] Below, an example of a film deposition apparatus capable of continuously forming the EL layer, upper electrode, and protective layer without contact with the atmosphere will be described. The film deposition apparatus exemplified below can be used to deposit the first EL layer 112, the second EL layer 114, the upper electrode 115, and the protective layer 135 in each light-emitting element 110.

[0191] A schematic diagram of the film deposition apparatus is shown in Figure 11A. The film deposition apparatus has a transport chamber TF at its center, and includes an input chamber LL, an output chamber UL, a processing chamber HT, film deposition chambers EL1 to EL8, a film deposition chamber ALD, and a film deposition chamber SP. The transport chamber TF has a transport robot RBT, which can transport substrates 101 into and out of each chamber. The chambers can also be called chambers.

[0192] Vacuum pumps are connected to the transport chamber TF and each of the rooms, maintaining a reduced pressure state. Gate valves are also installed between the transport chamber TF and each room, allowing for individual control of pressure, temperature, and other atmospheric conditions in each room.

[0193] The loading room LL is a room for loading the circuit board 101, and the unloading room UL is a room for unloading the circuit board 101. Both the loading room LL and the unloading room UL are equipped with gate valves that connect to the outside.

[0194] The substrate 101 can be heat-treated in the processing chamber HT. The processing chamber HT has a baking apparatus. For example, it may be a hot plate type baking apparatus, or a baking apparatus having a resistance heater or an infrared lamp.

[0195] In deposition chambers EL1 to EL8, films constituting the first EL layer 112 can be deposited. Deposition chambers EL1 to EL8 are equipped with, for example, a vacuum deposition apparatus or a sputtering apparatus. In addition, films constituting the second EL layer 114 can be deposited in deposition chambers EL1 to EL8.

[0196] For example, the apparatus includes a deposition chamber EL1 for depositing a hole injection layer, a deposition chamber EL2 for depositing a hole transport layer, a deposition chamber EL3 for depositing an electron blocking layer, a deposition chamber EL4 for depositing an emissive layer, a deposition chamber EL5 for depositing a hole blocking layer, a deposition chamber EL6 for depositing an electron transport layer, a deposition chamber EL7 for depositing an electron injection layer, and a deposition chamber EL8 for depositing a charge generation layer.

[0197] In the deposition chamber SP, the upper electrode 115 can be deposited. For example, the deposition chamber SP has a sputtering apparatus.

[0198] In the ALD deposition chamber, an insulating layer 199 and a protective layer 135 can be deposited. The ALD deposition chamber includes, for example, an ALD apparatus.

[0199] Although Figure 11A shows an example with one transport chamber TF, a configuration in which multiple transport chambers TF are connected is also possible. Figure 11B shows an example in which three transport chambers TF are connected. One transport robot RBT is provided for each transport chamber TF. In the example shown in Figure 11B, four to six rooms can be connected to one transport chamber TF, excluding the loading chamber LL and the unloading chamber UL. In Figure 11B, three rooms are connected to the transport chamber TF on the far right, and up to three more rooms can be added depending on the application.

[0200] Next, an example of a film deposition method using a film deposition apparatus will be described. First, as shown in Figure 5A, the substrate 101, which has been formed up to the partition wall 120, is brought into the film deposition apparatus from the loading chamber LL and subjected to heat treatment in the processing chamber HT. Heat treatment removes moisture and other substances adsorbed on the surface. Next, the hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, and electron injection layer are deposited in sequence in film deposition chambers EL1 to EL7. Next, the upper electrode is deposited in film deposition chamber SP. Next, the protective layer 135 is deposited in film deposition chamber ALD, and then the substrate 101 is discharged to the outside from the discharge chamber UL. In this way, the first EL layer 112, the second EL layer 114, the upper electrode 115, and the protective layer 135 can be formed continuously on the substrate 101 without exposing it to the atmosphere.

[0201] Furthermore, using the above-described film deposition apparatus, it is also possible to form a light-emitting element having a so-called tandem structure, which has multiple light-emitting layers separated by a charge generation layer.

[0202] First, as described above, the substrate 101 is heated in processing chamber HT, then sequentially placed into deposition chambers EL1 to EL7, and films are deposited sequentially from the hole injection layer to the electron injection layer. Next, the charge generation layer is deposited in deposition chamber EL8. After that, films are deposited again sequentially from the hole injection layer to the electron injection layer in deposition chambers EL1 to EL7. Subsequently, as described above, the upper electrode 115 is deposited in deposition chamber SP, the protective layer 135 is deposited in deposition chamber ALD, and the substrate 101 is discharged from discharge chamber UL. This makes it possible to fabricate a light-emitting element having a two-stage tandem structure in which two light-emitting layers are stacked with a charge generation layer in between.

[0203] In addition, at least one of the layers constituting the charge generation layer is deposited in the deposition chamber EL8. Furthermore, at least one of the electron injection layer and hole injection layer deposited before or after the deposition process in the deposition chamber EL8 can also serve as a layer constituting the charge generation layer. For example, when the charge generation layer has a laminated structure of an electron injection buffer layer, an electron relay layer, and a P-type layer, the electron injection layer may function as an electron injection buffer layer, and the hole injection layer may function as a P-type layer. In this case, the electron relay layer may also be deposited in the deposition chamber EL8.

[0204] Furthermore, in the case of a light-emitting element having an N-stage (N is a natural number of 2 or more) tandem structure, the film deposition process in deposition chambers EL1 to EL8 is repeated N-1 times, and then the film deposition in deposition chamber EL8 is omitted only for the last N time to form the upper electrode 115 and protective layer 135.

[0205] The above is a description of the film deposition apparatus and the film deposition method using it.

[0206] (Embodiment 2) This embodiment describes an example of the configuration of a display device according to one aspect of the present invention.

[0207] The display device of this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device of this embodiment can be used in electronic devices with relatively large screens, such as television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, smartphones, smartwatches, tablet devices, personal digital assistants, and audio playback devices.

[0208] [Display device 400A] Figure 12 shows a perspective view of the display device 400A, and Figure 13 shows a cross-sectional view of the display device 400A.

[0209] The display device 400A has a configuration in which substrate 452 and substrate 451 are bonded together. In Figure 12, substrate 452 is clearly indicated by a dashed line.

[0210] The display device 400A includes a display unit 462, a circuit 464, wiring 465, etc. Figure 12 shows an example in which IC 473 and FPC 472 are mounted on the display device 400A. Therefore, the configuration shown in Figure 12 can also be described as a display module having the display device 400A, an IC (integrated circuit), and an FPC.

[0211] For example, a scan line drive circuit can be used as circuit 464.

[0212] The wiring 465 has the function of supplying signals and power to the display unit 462 and the circuit 464. These signals and power are input to the wiring 465 from an external source via the FPC 472, or from the IC 473.

[0213] Figure 12 shows an example in which IC 473 is mounted on the substrate 451 using the COG (Chip On Glass) method or the COF (Chip On Film) method. IC 473 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display device 400A and the display module may be configured without an IC. Alternatively, the IC may be mounted on the FPC using the COF method or the like.

[0214] Figure 13 shows an example of a cross-section obtained by cutting a portion of the display device 400A, including the FPC 472, a portion of the circuit 464, a portion of the display unit 462, and a portion of the area including the end.

[0215] The display device 400A shown in Figure 13 has a transistor 201, a transistor 205, a light-emitting element 430a that emits red light, a light-emitting element 430b that emits green light, and a light-emitting element 430c that emits blue light, etc., between a substrate 451 and a substrate 452.

[0216] The light-emitting elements 430a, 430b, and 430c can be the light-emitting elements exemplified in Embodiment 1. Each light-emitting element 430 includes a pixel electrode 411a, 411b, or 411c, an island-shaped layer 412a, 412b, or 412c having at least a hole injection layer or an electron injection layer, an island-shaped layer 413a, 413b, or 413c each having a different light-emitting layer, and an upper electrode 414. For layers 412a, 412b, and 412c, any of the layers 112aR, 112aG, and the first EL layer 112B from the previous embodiment can be used, respectively. Furthermore, for layers 413a, 413b, and 413c, any of the laminated structures of layer 112bR and the second EL layer 114R, layer 112bG and the second EL layer 114G, and layer 112bB and the second EL layer 114B from the previous embodiment can be used, respectively.

[0217] Here, if the pixels of the display device have three types of subpixels, each having a light-emitting element with a different emission color, examples of such three subpixels include subpixels of three colors: R, G, and B; and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). If there are four such subpixels, examples of such four subpixels include subpixels of four colors: R, G, B, and white (W); and subpixels of four colors: R, G, B, and Y.

[0218] Each protective layer 416 and the substrate 452 are bonded together via an adhesive layer 442. For sealing the light-emitting element, a solid sealing structure or a hollow sealing structure can be applied. In Figure 13, the space 443 surrounded by the substrate 452, the adhesive layer 442, and the substrate 451 is filled with an inert gas (such as nitrogen or argon), indicating a hollow sealing structure. The adhesive layer 442 may be provided overlapping the light-emitting element. Alternatively, the space 443 surrounded by the substrate 452, the adhesive layer 442, and the substrate 451 may be filled with a resin different from the adhesive layer 442.

[0219] The light-emitting elements 430a, 430b, and 430c have an optical adjustment layer between the pixel electrode and the EL layer. Light-emitting element 430a has an optical adjustment layer 426a, light-emitting element 430b has an optical adjustment layer 426b, and light-emitting element 430c has an optical adjustment layer 426c. Details of the light-emitting elements can be found in Embodiment 1. Each optical adjustment layer 426 has a different thickness. It is also preferable that each optical adjustment layer 426 is made of the same material that is transparent and conductive. It is preferable to use a conductive metal oxide film containing indium or zinc as the optical adjustment layer 426.

[0220] The pixel electrodes 411a, 411b, and 411c are connected to the conductive layer 222b of the transistor 205 via openings provided in the insulating layer 214, insulating layer 215, and insulating layer 213, respectively.

[0221] The edges of the pixel electrodes and the optical adjustment layer are covered by an insulating layer 421. The pixel electrodes contain a material that reflects visible light, and the upper electrode 414, which is positioned as a counter electrode, contains a material that transmits visible light.

[0222] The light emitted by the light-emitting element is directed towards the substrate 452. It is preferable to use a material with high transparency to visible light for the substrate 452.

[0223] A partition wall 420 is provided on the insulating layer 421. The partition wall 420 can be described by referring to the partition wall 120 shown in Embodiment 1. The partition wall 420 is provided in a region that overlaps with the light-shielding layer 417. On the partition wall 420, a layer is provided which includes a part of the upper electrodes of two adjacent light-emitting elements on either side of the partition wall 420, and the same material as the EL layer. In addition, a protective layer 416 is provided covering the partition wall 420.

[0224] Both transistors 201 and 205 are formed on the substrate 451. These transistors can be manufactured using the same materials and the same process.

[0225] On the substrate 451, insulating layers 211, 213, 215, and 214 are provided in this order. A portion of insulating layer 211 functions as a gate insulating layer for each transistor. A portion of insulating layer 213 functions as a gate insulating layer for each transistor. Insulating layer 215 is provided covering the transistors. Insulating layer 214 is provided covering the transistors and functions as a planarization layer. The number of gate insulating layers and insulating layers covering the transistors are not limited and may be a single layer or two or more layers, respectively.

[0226] It is preferable to use a material that does not easily allow impurities such as water and hydrogen to diffuse into at least one layer of the insulating layer covering the transistor. This allows the insulating layer to function as a barrier layer. With such a configuration, the diffusion of impurities from the outside into the transistor can be effectively suppressed, thereby improving the reliability of the display device.

[0227] It is preferable to use inorganic insulating films for insulating layers 211, 213, and 215. Examples of inorganic insulating films that can be used include silicon nitride, silicon oxide nitride, silicon oxide, silicon nitride, aluminum oxide, and aluminum nitride. Alternatively, hafnium oxide, yttrium oxide, zirconium oxide, gallium oxide, tantalum oxide, magnesium oxide, lanthanum oxide, cerium oxide, and neodymium oxide may also be used. Furthermore, two or more of the above insulating films may be laminated together.

[0228] Here, organic insulating films often have lower barrier properties than inorganic insulating films. Therefore, it is preferable that the organic insulating film has an opening near the edge of the display device 400A. This prevents impurities from entering through the organic insulating film from the edge of the display device 400A. Alternatively, the organic insulating film may be formed so that its edge is inward from the edge of the display device 400A, so that the organic insulating film is not exposed at the edge of the display device 400A.

[0229] An organic insulating film is preferred for the insulating layer 214, which functions as a planarizing layer. Examples of materials that can be used as the organic insulating film include acrylic resins, polyimide resins, epoxy resins, polyamide resins, polyimidoamide resins, siloxane resins, benzocyclobutene resins, phenolic resins, and precursors of these resins.

[0230] In the region 228 shown in Figure 13, an opening is formed in the insulating layer 214. This prevents impurities from entering the display unit 462 from the outside through the insulating layer 214, even when an organic insulating film is used for the insulating layer 214. Therefore, the reliability of the display device 400A can be improved.

[0231] Transistors 201 and 205 have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as source and drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0232] The transistor structure of the display device of this embodiment is not particularly limited. For example, planar transistors, staggered transistors, inverse staggered transistors, etc., can be used. Furthermore, either a top-gate or bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below the semiconductor layer in which the channel is formed.

[0233] Transistors 201 and 205 are configured in which a semiconductor layer on which a channel is formed is sandwiched between two gates. The transistors may be driven by connecting the two gates and supplying them with the same signal. Alternatively, the threshold voltage of the transistors may be controlled by applying a potential to control the threshold voltage to one of the two gates and a potential to drive the other gate.

[0234] The crystallinity of the semiconductor material used in the transistor is not particularly limited; amorphous semiconductors, single-crystal semiconductors, or semiconductors with crystalline properties other than single crystals (microcrystalline semiconductors, polycrystalline semiconductors, or semiconductors with crystalline regions in part) may be used. Using a single-crystal semiconductor or a semiconductor with crystalline properties is preferable because it can suppress the degradation of transistor characteristics.

[0235] The semiconductor layer of the transistor preferably contains a metal oxide. In other words, the display device of this embodiment preferably uses a transistor (hereinafter referred to as an OS transistor) in which a metal oxide is used in the channel formation region. Alternatively, the semiconductor layer of the transistor may contain silicon. Examples of silicon include amorphous silicon and crystalline silicon (low-temperature polysilicon, single-crystal silicon, etc.).

[0236] The semiconductor layer preferably contains a metal oxide containing indium. In particular, it is especially preferable that it contains indium oxide.

[0237] Furthermore, the semiconductor layer preferably comprises, for example, indium, M (where M is one or more selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, M is preferably one or more selected from aluminum, gallium, yttrium, and tin.

[0238] In particular, it is preferable to use an oxide (also written as IGZO) containing indium (In), gallium (Ga), and zinc (Zn) as the semiconductor layer.

[0239] When the semiconductor layer is an In-M-Zn oxide, it is preferable that the atomic ratio of In in the In-M-Zn oxide is equal to or greater than the atomic ratio of M. Examples of such In-M-Zn oxide atomic ratios of metal elements include compositions where In:M:Zn = 1:1:1 or nearby, In:M:Zn = 1:1:1.2 or nearby, In:M:Zn = 2:1:3 or nearby, In:M:Zn = 3:1:2 or nearby, In:M:Zn = 4:2:3 or nearby, In:M:Zn = 4:2:4.1 or nearby, In:M:Zn = 5:1:3 or nearby, In:M:Zn = 5:1:6 or nearby, In:M:Zn = 5:1:7 or nearby, In:M:Zn = 5:1:8 or nearby, In:M:Zn = 6:1:6 or nearby, In:M:Zn = 5:2:5 or nearby, and so on. Note that "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0240] For example, when the atomic ratio is stated as In:Ga:Zn = 4:2:3 or nearby, it includes cases where, with In set to 4, Ga is between 1 and 3, and Zn is between 2 and 4. Also, when the atomic ratio is stated as In:Ga:Zn = 5:1:6 or nearby, it includes cases where, with In set to 5, Ga is greater than 0.5 and 2 or less, and Zn is between 5 and 7. Furthermore, when the atomic ratio is stated as In:Ga:Zn = 1:1:1 or nearby, it includes cases where, with In set to 1, Ga is greater than 0.5 and 2 or less, and Zn is greater than 0.5 and 2 or less.

[0241] The transistors in circuit 464 and the transistors in display unit 462 may have the same structure or different structures. The structures of the multiple transistors in circuit 464 may all be the same or there may be two or more different structures. Similarly, the structures of the multiple transistors in display unit 462 may all be the same or there may be two or more different structures.

[0242] A connection portion 204 is provided in the region of substrate 451 where substrate 452 does not overlap. At the connection portion 204, wiring 465 is electrically connected to FPC 472 via a conductive layer 466 and a connecting layer 242. The conductive layer 466 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as the pixel electrode and a conductive film obtained by processing the same conductive film as the optical adjustment layer. The conductive layer 466 is exposed on the upper surface of the connection portion 204. This allows the connection portion 204 and FPC 472 to be electrically connected via the connecting layer 242.

[0243] It is preferable to provide a light-shielding layer 417 on the surface of the substrate 452 that faces the substrate 451. Various optical components can also be arranged on the outside of the substrate 452. Examples of optical components include polarizing plates, phase difference plates, light diffusion layers (such as diffusion films), anti-reflective layers, and light-collecting films. Furthermore, an antistatic film to suppress the adhesion of dust, a water-repellent film to make it difficult for dirt to adhere, a hard coat film to suppress the occurrence of scratches during use, and an impact-absorbing layer may also be arranged on the outside of the substrate 452.

[0244] By providing a protective layer 416 that covers the light-emitting element, it is possible to suppress the entry of impurities such as water into the light-emitting element and improve the reliability of the light-emitting element.

[0245] In the region 228 near the edge of the display device 400A, it is preferable that the insulating layer 215 and the protective layer 416 are in contact with each other through an opening in the insulating layer 214. In particular, it is preferable that the inorganic insulating film of the insulating layer 215 and the inorganic insulating film of the protective layer 416 are in contact with each other. This makes it possible to suppress impurities from entering the display unit 462 from the outside through the organic insulating film. Therefore, the reliability of the display device 400A can be improved.

[0246] The protective layer 416 may have a laminated structure of an organic insulating film and an inorganic insulating film. In this case, it is preferable that the edges of the inorganic insulating film extend outward more than the edges of the organic insulating film.

[0247] Substrates 451 and 452 can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, etc., respectively. The substrate on the side that extracts light from the light-emitting element should be made of a material that transmits the light. Using flexible materials for substrates 451 and 452 can increase the flexibility of the display device. Alternatively, a polarizing plate may be used as substrate 451 or substrate 452.

[0248] As substrates 451 and 452, the following can be used: polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyacrylonitrile resin, acrylic resin, polyimide resin, polymethyl methacrylate resin, polycarbonate (PC) resin, polyethersulfone (PES) resin, polyamide resin (nylon, aramid, etc.), polysiloxane resin, cycloolefin resin, polystyrene resin, polyamide-imide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. One or both of substrates 451 and 452 may be made of glass of a thickness sufficient to provide flexibility.

[0249] Furthermore, when a circular polarizing plate is superimposed on a display device, it is preferable to use a substrate with high optical isotropy for the substrate of the display device. A substrate with high optical isotropy has low birefringence (or a small amount of birefringence).

[0250] For substrates with high optical isotropy, the absolute value of the retardation (phase difference) is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0251] Examples of films with high optical isotropy include triacetylcellulose (TAC, also known as cellulose triacetate) film, cycloolefin polymer (COP) film, cycloolefin copolymer (COC) film, and acrylic film.

[0252] Furthermore, when using a film as the substrate, the film may absorb water, potentially causing wrinkles or other shape changes in the display panel. Therefore, it is preferable to use a film with low water absorption for the substrate. For example, it is preferable to use a film with a water absorption rate of 1% or less, more preferable to use a film with a water absorption rate of 0.1% or less, and even more preferable to use a film with a water absorption rate of 0.01% or less.

[0253] As the adhesive layer 442, various types of curing adhesives can be used, such as UV-curing adhesives, reaction-curing adhesives, thermosetting adhesives, and anaerobic adhesives. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenolic resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, and EVA (ethylene vinyl acetate) resins. Materials with low moisture permeability, such as epoxy resins, are particularly preferred. Two-component mixed resins may also be used. Adhesive sheets may also be used.

[0254] As the connecting layer 242, an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like can be used.

[0255] Materials that can be used for conductive layers such as the gate, source, and drain of transistors, as well as various wirings and electrodes that constitute display devices, include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, as well as alloys mainly composed of these metals. Films containing these materials can be used as single layers or in a multilayer structure.

[0256] Furthermore, conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene can be used as the light-transmitting conductive material. Alternatively, metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metallic materials, can be used. Alternatively, nitrides of such metallic materials (e.g., titanium nitride) may be used. When using metallic materials or alloy materials (or their nitrides), it is preferable to make them thin enough to be light-transmitting. In addition, a laminated film of the above materials can be used as a conductive layer. For example, using a laminated film of a silver-magnesium alloy and indium tin oxide is preferable because it can enhance conductivity. These can also be used for conductive layers of various wirings and electrodes that constitute a display device, and for conductive layers of light-emitting elements (conductive layers that function as pixel electrodes or common electrodes).

[0257] Examples of insulating materials that can be used for each insulating layer include resins such as acrylic resin and epoxy resin, and inorganic insulating materials such as silicon oxide, silicon oxide nitride, silicon nitride, silicon oxide, and aluminum oxide.

[0258] [Display Device 400B] Figure 14A shows a cross-sectional view of the display device 400B. The perspective view of the display device 400B is the same as that of the display device 400A (Figure 12). Figure 14A shows an example of a cross-section of the display device 400B when a part of the area including the FPC 472, a part of the circuit 464, and a part of the display unit 462 are cut. In Figure 14A, an example of a cross-section is shown when a part of the display unit 462, in particular, including the light-emitting element 430b that emits green light and the light-emitting element 430c that emits blue light, is cut. Note that explanations of parts that are the same as those of the display device 400A may be omitted.

[0259] The display device 400B shown in Figure 14A has transistors 202, 210, light-emitting elements 430b, and 430c between substrates 453 and 454.

[0260] The substrate 454 and the protective layer 416 are bonded together via an adhesive layer 442. The adhesive layer 442 is provided in overlap with the light-emitting elements 430b and 430c, respectively, and a solid encapsulation structure is applied to the display device 400B.

[0261] The substrate 453 and the insulating layer 212 are bonded together by an adhesive layer 455.

[0262] The method for manufacturing the display device 400B involves first bonding a fabricated substrate, on which an insulating layer 212, transistors, and light-emitting elements are provided, to a substrate 454 on which a light-shielding layer 417 is provided, using an adhesive layer 442. Then, the fabricated substrate is peeled off and a substrate 453 is attached to the exposed surface, thereby transferring the components formed on the fabricated substrate to the substrate 453. It is preferable that both the substrate 453 and the substrate 454 are flexible. This increases the flexibility of the display device 400B.

[0263] The insulating layer 212 can be made of an inorganic insulating film that can be used for insulating layer 211, insulating layer 213, and insulating layer 215, respectively.

[0264] The pixel electrodes are connected to the conductive layer 222b of the transistor 210 through an opening in the insulating layer 214. The conductive layer 222b is connected to the low-resistance region 231n through openings in the insulating layer 215 and the insulating layer 225. The transistor 210 has the function of controlling the driving of the light-emitting element.

[0265] The ends of the pixel electrodes are covered by an insulating layer 421.

[0266] The light emitted by the light-emitting elements 430b and 430c is emitted towards the substrate 454. It is preferable to use a material with high transmittance (light transmission) to visible light for the substrate 454.

[0267] A connection portion 204 is provided in the region of substrate 453 that does not overlap with substrate 454. At the connection portion 204, wiring 465 is electrically connected to FPC 472 via a conductive layer 466 and a connecting layer 242. The conductive layer 466 can be obtained by processing the same conductive film as the pixel electrode. This allows the connection portion 204 and FPC 472 to be electrically connected via the connecting layer 242.

[0268] Transistors 202 and 210 each have a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, a semiconductor layer having a channel forming region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 that functions as a gate insulating layer, a conductive layer 223 that functions as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel forming region 231i. The insulating layer 225 is located between the conductive layer 223 and the channel forming region 231i.

[0269] The conductive layer 222a and the conductive layer 222b are each connected to the low-resistance region 231n via openings provided in the insulating layer 215. Of the conductive layer 222a and the conductive layer 222b, one functions as a source and the other functions as a drain.

[0270] Figure 14A shows an example in which the insulating layer 225 covers the top and sides of the semiconductor layer. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215, respectively.

[0271] On the other hand, in the transistor 209 shown in Figure 14B, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231, but does not overlap with the low-resistance region 231n. For example, the structure shown in Figure 14B can be fabricated by processing the insulating layer 225 using the conductive layer 223 as a mask. In Figure 14B, an insulating layer 215 is provided covering the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and conductive layer 222b are connected to the low-resistance region 231n, respectively, through openings in the insulating layer 215. Furthermore, an insulating layer 218 covering the transistor may also be provided.

[0272] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0273] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0274] (Embodiment 3) In this embodiment, an example of a display device configuration different from that described above will be explained.

[0275] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used in the display section of wearable devices that can be worn on the head, such as information terminals (wearable devices) such as wristwatches and bracelets, as well as VR devices such as head-mounted displays and AR devices such as glasses.

[0276] [Display Module] Figure 15A shows a perspective view of the display module 280. The display module 280 includes a display device 400C and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 400C, but may be the display device 400D or the display device 400E, which will be described later.

[0277] The display module 280 has substrates 291 and 292. The display module 280 has a display unit 281. The display unit 281 is an area in the display module 280 that displays an image, and is an area in which light from each pixel provided in the pixel unit 284, which will be described later, can be seen.

[0278] Figure 15B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286 composed of multiple wires.

[0279] The pixel section 284 has a plurality of pixels 284a arranged periodically. A magnified view of one pixel 284a is shown on the right side of Figure 15B. The pixel 284a has light-emitting elements 430a, 430b, and 430c, each with a different light-emitting color. The plurality of light-emitting elements may be arranged in a stripe arrangement as shown in Figure 15B. A stripe arrangement allows for a high-density arrangement of pixel circuits, thus providing a high-definition display device. Furthermore, various arrangement methods such as delta arrangement and pentile arrangement can be applied.

[0280] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0281] A single pixel circuit 283a is a circuit that controls the light emission of the three light-emitting elements of a single pixel 284a. A single pixel circuit 283a may be configured to have three circuits that control the light emission of a single light-emitting element. For example, a single pixel circuit 283a may have at least one selection transistor, one current control transistor (drive transistor), and a capacitive element for each light-emitting element. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to either the source or the drain. This realizes an active-matrix type display device.

[0282] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it may have at least one of the following: an arithmetic circuit, a memory circuit, and a power supply circuit.

[0283] The FPC 290 functions as wiring for supplying video signals or power potential, etc., to the circuit section 282 from an external source. An IC may also be mounted on the FPC 290.

[0284] The display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are superimposed on the lower side of the pixel section 284, thereby making the aperture ratio (effective display area ratio) of the display section 281 extremely high. For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and 95%, and more preferably 60% or more and 95%. Furthermore, it is possible to arrange the pixels 284a at an extremely high density, making the resolution of the display section 281 extremely high. For example, it is preferable that the pixels 284a in the display section 281 are arranged at a density of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, with a resolution of 20000 ppi or less, or 30000 ppi or less.

[0285] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as head-mounted displays, or in glasses-type AR devices. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display part 281, so even when the display part is magnified with lenses, pixels are not visible, enabling a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices with relatively small display parts. For example, it can be suitably used in the display part of wearable electronic devices such as wristwatches.

[0286] [Display device 400C] The display device 400C shown in Figure 16 has a substrate 301, light-emitting elements 430a, 430b, 430c, a capacitor 240, and a transistor 310.

[0287] The substrate 301 corresponds to the substrate 291 in Figures 15A and 15B.

[0288] The transistor 310 is a transistor having a channel-forming region in the substrate 301. The substrate 301 can be a semiconductor substrate such as a single-crystal silicon substrate. The transistor 310 comprises a portion of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region of the substrate 301 doped with impurities and functions as either a source or a drain. The insulating layer 314 is provided covering the side surface of the conductive layer 311.

[0289] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0290] Furthermore, an insulating layer 261 is provided to cover the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0291] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as the dielectric of the capacitor 240.

[0292] The conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to either the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided covering the conductive layer 241. The conductive layer 245 is provided in the region that overlaps with the conductive layer 241 via the insulating layer 243.

[0293] An insulating layer 255 is provided covering the capacitance 240, and light-emitting elements 430a, 430b, 430c, etc. are provided on the insulating layer 255. A protective layer 416 is provided on the light-emitting elements 430a, 430b, 430c, and a substrate 401 is bonded to the upper surface of the protective layer 416 by a resin layer 419. The substrate 401 corresponds to the substrate 292 in Figure 15A.

[0294] The pixel electrodes of the light-emitting element are electrically connected to either the source or drain of the transistor 310 by plugs 256 embedded in the insulating layer 255, a conductive layer 241 embedded in the insulating layer 254, and plugs 271 embedded in the insulating layer 261.

[0295] An insulating layer 421 is provided to cover the ends of the pixel electrodes. It is preferable to use an inorganic insulating material for the insulating layer 421. For example, inorganic insulating materials such as silicon oxide, silicon nitride, and aluminum oxide can be used.

[0296] A partition wall 420 is provided on the insulating layer 421. The partition wall 420 can be described by referring to the description of the partition wall 120 shown in Embodiment 1. On the partition wall 420, a layer is provided which includes a part of the upper electrodes of two adjacent light-emitting elements on either side of the partition wall 420, and the same material as the EL layer.

[0297] [Display Device 400D] The display device 400D shown in Figure 17 differs from the display device 400C mainly in its transistor configuration. Note that explanations of parts similar to those of the display device 400C may be omitted.

[0298] Transistor 320 is a transistor in which a metal oxide (also called an oxide semiconductor) is applied to the semiconductor layer where the channel is formed.

[0299] The transistor 320 has a semiconductor layer 321, an insulating layer 323, a conductive layer 324, a pair of conductive layers 325, an insulating layer 326, and a conductive layer 327.

[0300] The substrate 331 corresponds to the substrate 291 in Figures 15A and 15B. An insulating substrate or a semiconductor substrate can be used as the substrate 331.

[0301] An insulating layer 332 is provided on the substrate 331. The insulating layer 332 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the substrate 331 to the transistor 320, and prevents oxygen from detaching from the semiconductor layer 321 to the insulating layer 332. As the insulating layer 332, for example, a film that is less susceptible to hydrogen or oxygen diffusion than a silicon oxide film can be used, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0302] A conductive layer 327 is provided on an insulating layer 332, and an insulating layer 326 is provided covering the conductive layer 327. The conductive layer 327 functions as the first gate electrode of the transistor 320, and a part of the insulating layer 326 functions as the first gate insulating layer. It is preferable to use an oxide insulating film such as a silicon oxide film for at least the portion of the insulating layer 326 that is in contact with the semiconductor layer 321. It is preferable that the upper surface of the insulating layer 326 is flattened.

[0303] The semiconductor layer 321 is provided on the insulating layer 326. Preferably, the semiconductor layer 321 has a metal oxide (also called an oxide semiconductor) film having semiconductor properties. Details of materials that can be suitably used for the semiconductor layer 321 will be described later.

[0304] A pair of conductive layers 325 are provided in contact with the semiconductor layer 321 and function as source electrodes and drain electrodes.

[0305] Furthermore, an insulating layer 328 is provided covering the top and side surfaces of the pair of conductive layers 325, as well as the side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided on the insulating layer 328. The insulating layer 328 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the semiconductor layer 321 from the insulating layer 264, etc., and to prevent oxygen from detaching from the semiconductor layer 321. An insulating film similar to that used for the insulating layer 332 can be used for the insulating layer 328.

[0306] The insulating layer 328 and the insulating layer 264 are provided with openings that reach the semiconductor layer 321. Inside these openings, the insulating layer 323 and the conductive layer 324 are embedded, in contact with the insulating layer 264, the insulating layer 328, the side surfaces of the conductive layer 325, and the upper surface of the semiconductor layer 321. The conductive layer 324 functions as a second gate electrode, and the insulating layer 323 functions as a second gate insulating layer.

[0307] The upper surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are flattened so that their heights are roughly the same, and the insulating layer 329 and insulating layer 265 are provided covering them.

[0308] Insulating layers 264 and 265 function as interlayer insulating layers. Insulating layer 329 functions as a barrier layer to prevent impurities such as water or hydrogen from diffusing into the transistor 320 from the insulating layer 265, etc. As insulating layer 329, an insulating film similar to that used for insulating layers 328 and 332 can be used.

[0309] A plug 274, which is electrically connected to one of the pair of conductive layers 325, is provided so as to be embedded in the insulating layer 265, insulating layer 329, and insulating layer 264. Here, it is preferable that the plug 274 has a conductive layer 274a that covers the sides of the openings of the insulating layer 265, insulating layer 329, insulating layer 264, and insulating layer 328, and a part of the upper surface of the conductive layer 325, and a conductive layer 274b that is in contact with the upper surface of the conductive layer 274a. In this case, it is preferable to use a conductive material that does not easily allow hydrogen and oxygen to diffuse as the conductive layer 274a.

[0310] The configuration from the insulating layer 254 to the substrate 401 in the display device 400D is the same as that of the display device 400C.

[0311] [Display Device 400E] The display device 400E shown in Figure 18 has a configuration in which a transistor 310 with a channel formed on a substrate 301 and a transistor 320 containing a metal oxide in the semiconductor layer where the channel is formed are stacked. Note that the same parts as those of display devices 400C and 400D may be omitted from the explanation.

[0312] An insulating layer 261 is provided covering the transistor 310, and a conductive layer 251 is provided on the insulating layer 261. An insulating layer 262 is provided covering the conductive layer 251, and a conductive layer 252 is provided on the insulating layer 262. The conductive layers 251 and 252 each function as wiring. An insulating layer 263 and an insulating layer 332 are provided covering the conductive layer 252, and a transistor 320 is provided on the insulating layer 332. An insulating layer 265 is provided covering the transistor 320, and a capacitor 240 is provided on the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0313] Transistor 320 can be used as a transistor constituting a pixel circuit. Transistor 310 can also be used as a transistor constituting a pixel circuit, or as a transistor constituting a drive circuit (gate line drive circuit, source line drive circuit) for driving the pixel circuit. Furthermore, transistors 310 and 320 can be used as transistors constituting various circuits such as arithmetic circuits or memory circuits.

[0314] This configuration allows for the formation of not only pixel circuits but also drive circuits and other components directly beneath the light-emitting element, making it possible to miniaturize the display device compared to cases where the drive circuits are located around the display area.

[0315] The configuration examples illustrated in this embodiment, and the corresponding drawings, etc., can be appropriately combined with other configuration examples or drawings, etc., at least in part.

[0316] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0317] (Embodiment 4) In this embodiment, a light-emitting element (also called a light-emitting device) that can be used in a display device according to one aspect of the present invention will be described.

[0318] In this specification, a light-emitting device (also called a light-emitting element) has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. Examples of the layers (also called functional layers) of the EL layer include a light-emitting layer, a carrier injection layer (hole injection layer and electron injection layer), a carrier transport layer (hole transport layer and electron transport layer), and a carrier block layer (hole block layer and electron block layer).

[0319] In this specification, devices fabricated using a metal mask or FMM (Fine Metal Mask, a high-resolution metal mask) may be referred to as MM (Metal Mask) structured devices. In addition, in this specification, devices fabricated without using a metal mask or FMM may be referred to as MML (Metal Maskless) structured devices.

[0320] In this specification, a structure in which different light-emitting layers are created or painted for each color of light-emitting device (here, blue (B), green (G), and red (R)) may be referred to as an SBS (Side By Side) structure. The SBS structure allows for optimization of materials and configuration for each light-emitting device, thus increasing the freedom of material and configuration selection and facilitating improvements in brightness and reliability. Furthermore, in this specification, a light-emitting device capable of emitting white light may be referred to as a white light-emitting device. A white light-emitting device can be combined with a colored layer (for example, a color filter) to create a full-color display device.

[0321] In this specification, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or electron injection layer may be called a "carrier injection layer," a hole transport layer or electron transport layer may be called a "carrier transport layer," and a hole blocking layer or electron blocking layer may be called a "carrier blocking layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier blocking layer may not always be clearly distinguishable. Furthermore, a single layer may combine the functions of two or three of the carrier injection layer, carrier transport layer, and carrier blocking layer.

[0322] [Light-emitting devices] Light-emitting devices can be broadly classified into single-structure and tandem-structure. A single-structure device has one light-emitting unit between a pair of electrodes. This light-emitting unit has a configuration that includes one or more light-emitting layers. To obtain white light emission in a single-structure device, one should select light-emitting layers such that the light emitted by each of the two or more layers can produce white light. For example, in the case of two colors, by making the light-emitting color of the first light-emitting layer and the light-emitting color of the second light-emitting layer complementary colors, a configuration that produces white light emission as a whole can be obtained. Also, when obtaining white light emission using three or more light-emitting layers, the light-emitting device can be configured so that the light-emitting colors of the three or more layers combine to produce white light emission as a whole.

[0323] A tandem device has multiple light-emitting units between a pair of electrodes. Each light-emitting unit includes one or more light-emitting layers. By using light-emitting layers that emit light of the same color in each light-emitting unit, the brightness per unit current can be increased, and a more reliable light-emitting device can be achieved compared to a single-unit structure. To obtain white light emission in a tandem structure, the light from the light-emitting layers of multiple light-emitting units can be combined to produce white light emission. The combination of light-emitting colors that produces white light emission is the same as that for a single-unit structure. In a tandem device, it is preferable to provide an intermediate layer, such as a charge-generating layer, between the multiple light-emitting units.

[0324] When comparing white light-emitting devices with SBS structure light-emitting devices, SBS structure light-emitting devices can consume less power than white light-emitting devices. On the other hand, white light-emitting devices have a simpler manufacturing process than SBS structure light-emitting devices, resulting in lower manufacturing costs and higher manufacturing yields.

[0325] As shown in Figure 19A, the light-emitting device has an EL layer 763 between a pair of electrodes (lower electrode 761 and upper electrode 762). The EL layer 763 can be composed of multiple layers, such as layer 780, light-emitting layer 771, and layer 790.

[0326] The light-emitting layer 771 has at least a light-emitting substance (also called a light-emitting material).

[0327] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layer 780 has one or more of the following: a layer containing a material with high hole injection properties (hole injection layer), a layer containing a material with high hole transport properties (hole transport layer), and a layer containing a material with high electron blocking properties (electron blocking layer). Similarly, layer 790 has one or more of the following: a layer containing a material with high electron injection properties (electron injection layer), a layer containing a material with high electron transport properties (electron transport layer), and a layer containing a material with high hole blocking properties (hole blocking layer). When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 780 and 790 have the opposite configurations to those described above.

[0328] A configuration having a layer 780, a light-emitting layer 771, and a layer 790 provided between a pair of electrodes can function as a single light-emitting unit, and in this specification, the configuration shown in Figure 19A is referred to as a single structure.

[0329] Furthermore, Figure 19B shows a modified example of the EL layer 763 of the light-emitting device shown in Figure 19A. Specifically, the light-emitting device shown in Figure 19B includes a layer 781 on the lower electrode 761, a layer 782 on the layer 781, a light-emitting layer 771 on the layer 782, a layer 791 on the light-emitting layer 771, a layer 792 on the layer 791, and an upper electrode 762 on the layer 792.

[0330] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 781 can be a hole injection layer, layer 782 a hole transport layer, layer 791 an electron transport layer, and layer 792 an electron injection layer. Also, when the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layer 781 can be an electron injection layer, layer 782 an electron transport layer, layer 791 a hole transport layer, and layer 792 a hole injection layer. By using such a layer structure, carriers can be efficiently injected into the light-emitting layer 771, and the efficiency of carrier recombination within the light-emitting layer 771 can be increased.

[0331] As shown in Figures 19C and 19D, a configuration in which multiple light-emitting layers (light-emitting layers 771, 772, and 773) are provided between layer 780 and layer 790 is also a variation of the single structure. Although Figures 19C and 19D show an example with three light-emitting layers, the number of light-emitting layers in a single-structure light-emitting device may be two or four or more.

[0332] Furthermore, a single-layer light-emitting device may have a buffer layer between the two light-emitting layers.

[0333] Furthermore, as shown in Figures 19E and 19F, a configuration in which multiple light-emitting units (light-emitting units 763a and 763b) are connected in series via a charge generation layer 785 (also called an intermediate layer) is referred to as a tandem structure in this specification. The tandem structure may also be called a stack structure. By using a tandem structure, a light-emitting device capable of high-brightness emission can be created. In addition, compared to a single structure, the tandem structure can reduce the current required to obtain the same brightness, thereby improving reliability.

[0334] Figures 19D and 19F show examples in which the display device has a layer 764 that overlaps with the light-emitting device. Figure 19D shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 19C, and Figure 19F shows an example in which layer 764 overlaps with the light-emitting device shown in Figure 19E. In Figures 19D and 19F, a conductive film that transmits visible light is used for the upper electrode 762 in order to extract light to the upper electrode 762 side.

[0335] As layer 764, one or both of the following can be used: a color conversion layer and / or a color filter (coloring layer).

[0336] In Figures 19C and 19D, the light-emitting layers 771, 772, and 773 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. For example, light-emitting materials that emit blue light may be used for the light-emitting layers 771, 772, and 773. In subpixels that emit blue light, the blue light emitted by the light-emitting device can be extracted. In subpixels that emit red light and subpixels that emit green light, by providing a color conversion layer as layer 764 as shown in Figure 19D, the blue light emitted by the light-emitting device can be converted into longer wavelength light, and red or green light can be extracted. It is also preferable to use both a color conversion layer and a coloring layer as layer 764. Some of the light emitted by the light-emitting device may be transmitted directly without being converted by the color conversion layer. By extracting the light that has passed through the color conversion layer via the coloring layer, the color of light other than the desired color can be absorbed by the coloring layer, and the color purity of the light emitted by the subpixel can be increased.

[0337] Furthermore, in Figures 19C and 19D, different light-emitting materials with different emission colors may be used for each of the light-emitting layers 771, 772, and 773. White light emission can be obtained by selecting light-emitting layers that can produce white light through the emission of each of the light-emitting layers 771, 772, and 773. For example, a single-structure light-emitting device preferably has a light-emitting layer having a light-emitting material that emits blue light, and a light-emitting layer having a light-emitting material that emits visible light with a longer wavelength than blue light.

[0338] A color filter may be provided as layer 764, as shown in Figure 19D. By passing white light through the color filter, light of the desired color can be obtained.

[0339] For example, if a single-structure light-emitting device has three light-emitting layers, it is preferable that it has a light-emitting layer having a light-emitting material that emits red (R) light, a light-emitting layer having a light-emitting material that emits green (G) light, and a light-emitting layer having a light-emitting material that emits blue (B) light. The stacking order of the light-emitting layers can be R, G, B from the anode side, or R, B, G from the anode side, etc. In this case, a buffer layer may be provided between R and G or B.

[0340] Furthermore, for example, when a single-structure light-emitting device has two light-emitting layers, a configuration is preferred in which one light-emitting layer has a light-emitting material that emits blue (B) light, and the other light-emitting layer has a light-emitting material that emits yellow (Y) light. This configuration may be referred to as a BY single structure.

[0341] A light-emitting device that emits white light preferably contains two or more types of light-emitting materials. To obtain white light emission, one should select light-emitting layers such that the light emission of each of the two or more light-emitting materials can produce white light. For example, in the case of two colors, by making the light emission color of the first light-emitting layer and the light emission color of the second light-emitting layer complementary colors, a light-emitting device that emits white light as a whole can be obtained. Also, when obtaining white light emission using three or more light-emitting layers, the light emission colors of the three or more light-emitting layers should be combined to produce white light as a whole.

[0342] In addition, in Figures 19C and 19D, as shown in Figure 19B, layer 780 and layer 790 may each be independently constructed as a laminated structure consisting of two or more layers.

[0343] Furthermore, in Figures 19E and 19F, the light-emitting layer 771 and the light-emitting layer 772 may be made of light-emitting materials that emit light of the same color, or even the same light-emitting material. For example, in a light-emitting device having sub-pixels that emit light of each color, the light-emitting layer 771 and the light-emitting layer 772 may each be made of light-emitting materials that emit blue light. In the sub-pixels that emit blue light, the blue light emitted by the light-emitting device can be extracted. In addition, in the sub-pixels that emit red light and the sub-pixels that emit green light, by providing a color conversion layer as layer 764 as shown in Figure 19F, the blue light emitted by the light-emitting device can be converted into longer wavelength light, and red or green light can be extracted. Furthermore, it is preferable to use both a color conversion layer and a coloring layer as layer 764.

[0344] Furthermore, in Figures 19E and 19F, different luminescent materials with different emission colors may be used for the luminescent layer 771 and the luminescent layer 772. When the light emitted by the luminescent layer 771 and the light emitted by the luminescent layer 772 are complementary colors, white light emission is obtained. A color filter may be provided as layer 764 as shown in Figure 19F. By passing white light through the color filter, light of a desired color can be obtained.

[0345] In Figures 19E and 19F, examples are shown in which the light-emitting unit 763a has one light-emitting layer 771 and the light-emitting unit 763b has one light-emitting layer 772, but the design is not limited to this. The light-emitting unit 763a and the light-emitting unit 763b may each have two or more light-emitting layers.

[0346] Furthermore, while Figures 19E and 19F illustrate a light-emitting device having two light-emitting units, the device is not limited to this. A light-emitting device may have three or more light-emitting units. A configuration with two light-emitting units may be referred to as a two-stage tandem structure, and a configuration with three light-emitting units may be referred to as a three-stage tandem structure.

[0347] Furthermore, in Figures 19E and 19F, the light-emitting unit 763a has layer 780a, light-emitting layer 771, and layer 790a, and the light-emitting unit 763b has layer 780b, light-emitting layer 772, and layer 790b.

[0348] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, layers 780a and 780b each have one or more of the following: a hole injection layer, a hole transport layer, and an electron blocking layer. Similarly, layers 790a and 790b each have one or more of the following: an electron injection layer, an electron transport layer, and a hole blocking layer. When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, layers 780a and 790a have the opposite configurations to those described above, and layers 780b and 790b also have the opposite configurations to those described above.

[0349] When the lower electrode 761 is the anode and the upper electrode 762 is the cathode, for example, layer 780a may have a hole injection layer and a hole transport layer on the hole injection layer, and may further have an electron blocking layer on the hole transport layer. Layer 790a may have an electron transport layer and may further have a hole blocking layer between the light-emitting layer 771 and the electron transport layer. Layer 780b may have a hole transport layer and may further have an electron blocking layer on the hole transport layer. Layer 790b may have an electron transport layer and an electron injection layer on the electron transport layer, and may further have a hole blocking layer between the light-emitting layer 772 and the electron transport layer. When the lower electrode 761 is the cathode and the upper electrode 762 is the anode, for example, layer 780a may have an electron injection layer and an electron transport layer on the electron injection layer, and may further have a hole blocking layer on the electron transport layer. Furthermore, layer 790a may have a hole transport layer and an electron blocking layer between the light-emitting layer 771 and the hole transport layer. Also, layer 780b may have an electron transport layer and an electron blocking layer on the electron transport layer. Also, layer 790b may have a hole transport layer and a hole injection layer on the hole transport layer and an electron blocking layer between the light-emitting layer 772 and the hole transport layer.

[0350] Furthermore, when fabricating a tandem light-emitting device, the two light-emitting units are stacked with a charge generation layer 785 in between. The charge generation layer 785 has the function of injecting electrons into one of the two light-emitting units and holes into the other when a voltage is applied between the pair of electrodes.

[0351] Furthermore, an example of a tandem-structured light-emitting device is the configuration shown in Figures 20A to 20C.

[0352] Figure 20A shows a configuration having three light-emitting units. In Figure 20A, multiple light-emitting units (light-emitting units 763a, 763b, and 763c) are connected in series via a charge generation layer 785. Light-emitting unit 763a has layer 780a, light-emitting layer 771, and layer 790a; light-emitting unit 763b has layer 780b, light-emitting layer 772, and layer 790b; and light-emitting unit 763c has layer 780c, light-emitting layer 773, and layer 790c. Layer 780c can use a configuration applicable to layers 780a and 780b, and layer 790c can use a configuration applicable to layers 790a and 790b.

[0353] In Figure 20A, the light-emitting layers 771, 772, and 773 can each have a light-emitting material that emits light of the same color. Specifically, the light-emitting layers 771, 772, and 773 can all be configured to have a blue (B) light-emitting material (a so-called B / B / B three-stage tandem structure). Note that "b / a" means that a light-emitting unit having a light-emitting material that emits light of color a is provided on a light-emitting unit having a light-emitting material, via a charge generation layer, and a and b represent colors.

[0354] Furthermore, in Figure 20A, some or all of the light-emitting layers 771, 772, and 773 may be made of light-emitting materials with different emission colors. Examples of combinations of emission colors for the light-emitting layers 771, 772, and 773 include a configuration where two are blue (B) and the remaining one is yellow (Y), and a configuration where one is red (R), another is green (G), and the remaining one is blue (B).

[0355] The light-emitting materials that each emit light of the same color are not limited to the above configuration. For example, as shown in Figure 20B, a tandem-type light-emitting device may be used in which multiple light-emitting units having multiple light-emitting layers are stacked. Figure 20B shows a configuration in which two light-emitting units (light-emitting unit 763a and light-emitting unit 763b) are connected in series via a charge-generating layer 785. Light-emitting unit 763a has layer 780a, light-emitting layer 771a, light-emitting layer 771b, light-emitting layer 771c, and layer 790a, and light-emitting unit 763b has layer 780b, light-emitting layer 772a, light-emitting layer 772b, light-emitting layer 772c, and layer 790b.

[0356] In Figure 20B, the light-emitting unit 763a is configured to emit white light (W) by selecting light-emitting materials for light-emitting layers 771a, 771b, and 771c so that the combination of their respective emission colors results in white light. Similarly, the light-emitting unit 763b is configured to emit white light (W) by selecting light-emitting materials for light-emitting layers 772a, 772b, and 772c so that the combination of their respective emission colors results in white light. In other words, the configuration shown in Figure 20B is a two-stage tandem structure of W / W. There are no particular limitations on the stacking order of the light-emitting materials. The implementer can select the optimal stacking order as appropriate. In addition, although not shown, a three-stage tandem structure of W / W / W or a tandem structure of four or more stages may also be used.

[0357] Furthermore, when using a tandem light-emitting device, there are two-stage tandem structures: B / Y or Y / B having a light-emitting unit that emits yellow (Y) light and a light-emitting unit that emits blue (B) light; R・G / B or B / R・G having a light-emitting unit that emits red (R) and green (G) light and a light-emitting unit that emits blue (B) light; and a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow (Y) light, and a light-emitting unit that emits blue (B) light. Examples include a B / Y / B three-stage tandem structure having a light-emitting unit that emits blue (B) light, a light-emitting unit that emits yellow-green (YG) light, and a light-emitting unit that emits blue (B) light in that order, and a B / YG / B three-stage tandem structure having a light-emitting unit that emits blue (B) light, a light-emitting unit that emits green (G) light, and a light-emitting unit that emits blue (B) light in that order. Note that "a and b" means that one light-emitting unit has a light-emitting material that emits light a and a light-emitting material that emits light b.

[0358] Furthermore, as shown in Figure 20C, a light-emitting unit having one light-emitting layer and a light-emitting unit having multiple light-emitting layers may be combined.

[0359] Specifically, in the configuration shown in Figure 20C, a plurality of light-emitting units (light-emitting units 763a, 763b, and 763c) are connected in series via a charge generation layer 785. Furthermore, light-emitting unit 763a has a layer 780a, a light-emitting layer 771, and a layer 790a; light-emitting unit 763b has a layer 780b, a light-emitting layer 772a, a light-emitting layer 772b, a light-emitting layer 772c, and a layer 790b; and light-emitting unit 763c has a layer 780c, a light-emitting layer 773, and a layer 790c.

[0360] For example, in the configuration shown in Figure 20C, a three-stage tandem structure of B / R, G, YG / B can be applied, where light-emitting unit 763a is a light-emitting unit that emits blue (B) light, light-emitting unit 763b is a light-emitting unit that emits red (R), green (G), and yellow-green (YG) light, and light-emitting unit 763c is a light-emitting unit that emits blue (B) light.

[0361] For example, the number of layers and color order of the light-emitting unit can be, from the anode side, a two-layer structure of B and Y, a two-layer structure of B and light-emitting unit X, a three-layer structure of B, Y, B, or a three-layer structure of B, X, B. The number of layers and color order of the light-emitting layers in light-emitting unit X can be, from the anode side, a two-layer structure of R and Y, a two-layer structure of R and G, a two-layer structure of G and R, a three-layer structure of G, R, G, or a three-layer structure of R, G, R. In addition, other layers may be provided between the two light-emitting layers.

[0362] Next, we will describe materials that can be used in light-emitting devices.

[0363] Of the lower electrode 761 and the upper electrode 762, the electrode that extracts light preferably uses a conductive film that transmits visible light. Furthermore, it is preferable to use a conductive film that reflects visible light on the electrode that does not extract light. In addition, if the display device has a light-emitting device that emits infrared light, it is preferable to use a conductive film that transmits both visible light and infrared light on the electrode that extracts light, and a conductive film that reflects both visible light and infrared light on the electrode that does not extract light.

[0364] Furthermore, a conductive film that transmits visible light may also be used on the electrode that does not extract light. In this case, it is preferable to place the electrode between the reflective layer and the EL layer 763. In other words, the light emitted from the EL layer 763 may be reflected by the reflective layer and extracted from the display device.

[0365] As the material for forming the pair of electrodes of the light-emitting device, metals, alloys, electrically conductive compounds, and mixtures thereof can be used as appropriate. Specifically, such materials include metals such as aluminum, magnesium, titanium, chromium, manganese, iron, cobalt, nickel, copper, gallium, zinc, indium, tin, molybdenum, tantalum, tungsten, palladium, gold, platinum, silver, yttrium, and neodymium, and alloys containing these in appropriate combinations. Other materials include indium tin oxide (In-Sn oxide, also called ITO), In-Si-Sn oxide (also called ITSO), indium zinc oxide (In-Zn oxide), and In-W-Zn oxide. Furthermore, such materials include aluminum-containing alloys (aluminum alloys) such as aluminum, nickel, and lanthanum alloys (Al-Ni-La), and silver-containing alloys such as silver-magnesium alloys and silver-palladium-copper alloys (Ag-Pd-Cu, also written as APC). Other materials include elements belonging to Group 1 or Group 2 of the periodic table not exemplified above (e.g., lithium, cesium, calcium, strontium), rare earth metals such as europium and ytterbium, alloys containing these in appropriate combinations, graphene, and the like.

[0366] It is preferable that the light-emitting device has a microcavity structure. Therefore, it is preferable that one of the pair of electrodes in the light-emitting device is a semitransmissive / semi-reflective electrode that transmits and reflects visible light, and the other is a reflective electrode that reflects visible light. By having a microcavity structure in the light-emitting device, the light emitted from the light-emitting layer can be resonated between the two electrodes, thereby strengthening the light emitted from the light-emitting device.

[0367] Furthermore, the semi-transparent / semi-reflective electrode can have a laminated structure consisting of a conductive layer that can be used as a reflective electrode and a conductive layer that can be used as an electrode that transmits visible light (also called a transparent electrode).

[0368] The light transmittance of the transparent electrode shall be 40% or more. For example, it is preferable to use an electrode with a visible light transmittance (light with a wavelength of 400 nm or more and less than 750 nm) of 40% or more for the transparent electrode of a light-emitting device. The visible light reflectance of the semi-transparent and semi-reflective electrodes shall be 10% or more and 95% or less, preferably 30% or more and 80% or less. The visible light reflectance of the reflective electrode shall be 40% or more and 100% or less, preferably 70% or more and 100% or less. The resistivity of these electrodes shall be 1 × 10⁻⁶ −２ A value of Ωcm or less is preferable.

[0369] A light-emitting device has at least a light-emitting layer. Furthermore, a light-emitting device may have layers other than the light-emitting layer, including materials with high hole injection properties, materials with high hole transport properties, hole-blocking materials, materials with high electron transport properties, electron-blocking materials, materials with high electron injection properties, or bipolar materials (materials with high electron and hole transport properties). For example, a light-emitting device can have a configuration that includes, in addition to the light-emitting layer, one or more layers from among a hole injection layer, a hole transport layer, a hole-blocking layer, a charge generation layer, an electron-blocking layer, an electron transport layer, and an electron injection layer.

[0370] The light-emitting device may use either low-molecular-weight compounds or high-molecular-weight compounds, and may also contain inorganic compounds. The layers constituting the light-emitting device can be formed by methods such as vapor deposition (including vacuum deposition), transfer, printing, inkjet, and coating.

[0371] The light-emitting layer has one or more types of light-emitting materials. The light-emitting materials may include substances that exhibit light-emitting colors such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red, as appropriate. Furthermore, materials that emit near-infrared light may also be used as light-emitting materials.

[0372] Examples of luminescent materials include fluorescent materials, phosphorescent materials, TADF materials, and quantum dot materials.

[0373] Examples of fluorescent materials include pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives.

[0374] Examples of phosphorescent materials include organometallic complexes (especially iridium complexes) having a 4H-triazole skeleton, 1H-triazole skeleton, imidazole skeleton, pyrimidine skeleton, pyrazine skeleton, or pyridine skeleton; organometallic complexes (especially iridium complexes) using phenylpyridine derivatives having electron-withdrawing groups as ligands; platinum complexes; and rare earth metal complexes.

[0375] The light-emitting layer may contain one or more types of organic compounds (host material, assist material, etc.) in addition to the light-emitting substance (guest material). One or more types of organic compounds may include materials with high hole transport properties (hole transport materials) and / or materials with high electron transport properties (electron transport materials). As the hole transport material, one of the materials with high hole transport properties that can be used in the hole transport layer, as described later, may be used. As the electron transport material, one of the materials with high electron transport properties that can be used in the electron transport layer, as described later, may be used. Furthermore, one or more types of organic compounds may include bipolar materials or TADF materials.

[0376] The light-emitting layer preferably comprises, for example, a phosphorescent material and a combination of a hole-transporting material and an electron-transporting material that readily forms an excitation complex. This configuration allows for efficient emission using ExTET (Exciplex-Triplet Energy Transfer), which is energy transfer from the excitation complex to the light-emitting substance (phosphorescent material). By selecting a combination that forms an excitation complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the light-emitting substance, energy transfer becomes smoother, and light emission can be obtained efficiently. This configuration simultaneously achieves high efficiency, low-voltage operation, and a long lifespan for the light-emitting device.

[0377] The hole injection layer is a layer that injects holes from the anode into the hole transport layer, and is a layer containing a material with high hole injection capabilities. Examples of materials with high hole injection capabilities include aromatic amine compounds and composite materials containing hole transport materials and acceptor materials (electron-accepting materials).

[0378] As the hole-transporting material, a material with high hole-transporting properties that can be used in the hole-transporting layer, as described later, can be used.

[0379] As acceptor materials, for example, oxides of metals belonging to groups 4 through 8 of the periodic table can be used. Specifically, these include molybdenum oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly preferred because it is stable in the atmosphere, has low hygroscopicity, and is easy to handle. Organic acceptor materials containing fluorine can also be used. Furthermore, organic acceptor materials such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives can also be used.

[0380] For example, as a material with high hole injection properties, a material containing a hole transport material and an oxide of a metal belonging to Group 4 to Group 8 of the periodic table (typically molybdenum oxide) may be used.

[0381] The hole transport layer is a layer that transports holes injected from the anode by the hole injection layer to the light-emitting layer. The hole transport layer is a layer containing a hole-transporting material. The hole-transporting material is 1 × 10 −６ cm ２ Materials having a hole mobility of 1 / Vs or higher are preferred. Other materials can also be used as long as they have higher hole transport capabilities than electron transport. Preferred hole transport materials include π-electron-rich heteroaromatic compounds (e.g., carbazole derivatives, thiophene derivatives, furan derivatives, etc.) and aromatic amines (compounds having an aromatic amine skeleton), which are materials with high hole transport capabilities.

[0382] The electron blocking layer is provided in contact with the light-emitting layer. The electron blocking layer is a layer containing a material that has hole-transporting properties and is capable of blocking electrons. Among the hole-transporting materials mentioned above, a material that has electron-blocking properties can be used for the electron blocking layer.

[0383] Because electron-blocking layers possess hole-transporting properties, they can also be called hole-transporting layers. Furthermore, among hole-transporting layers, those that exhibit electron-blocking properties can also be called electron-blocking layers.

[0384] The electron transport layer is a layer that transports electrons injected from the cathode by the electron injection layer to the light-emitting layer. The electron transport layer is a layer containing an electron-transporting material. The electron-transporting material is 1 × 10⁻¹⁶ −６ cm ２ Materials having an electron mobility of 1 / Vs or higher are preferred. However, other materials can also be used as long as they have higher electron transport capabilities than holes. Examples of electron-transporting materials include metal complexes having a quinoline skeleton, metal complexes having a benzoquinoline skeleton, metal complexes having an oxazole skeleton, metal complexes having a thiazole skeleton, as well as oxadiazole derivatives, triazole derivatives, imidazole derivatives, oxazole derivatives, thiazole derivatives, phenanthroline derivatives, quinoline derivatives having a quinoline ligand, benzoquinoline derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and other π-electron-deficient heteroaromatic compounds containing nitrogen-containing heteroaromatic compounds.

[0385] The hole-blocking layer is provided in contact with the light-emitting layer. The hole-blocking layer is a layer containing a material that has electron-transporting properties and is capable of blocking holes. Among the electron-transporting materials mentioned above, a material that has hole-blocking properties can be used for the hole-blocking layer.

[0386] Because hole-blocking layers possess electron-transporting properties, they can also be called electron-transporting layers. Furthermore, among electron-transporting layers, those that exhibit hole-blocking properties can also be called hole-blocking layers.

[0387] The electron injection layer is a layer that injects electrons from the cathode to the electron transport layer, and is a layer containing a material with high electron injection potential. Alkali metals, alkaline earth metals, or compounds thereof can be used as materials with high electron injection potential. Composite materials containing both electron transport materials and donor materials (electron-donating materials) can also be used as materials with high electron injection potential.

[0388] Furthermore, it is preferable that the lowest unoccupied molecular orbital (LUMO) level of a material with high electron injection capacity has a small difference (specifically, 0.5 eV or less) from the work function value of the material used for the cathode.

[0389] The electron injection layer contains, for example, lithium, cesium, ytterbium, lithium fluoride (LiF), cesium fluoride (CsF), and calcium fluoride (CaF). ｘ (where X is any number), 8-(quinolinolato)lithium (abbreviation: Liq), 2-(2-pyridyl)phenolatritium (abbreviation: LiPP), 2-(2-pyridyl)-3-pyridinolatritium (abbreviation: LiPPy), 4-phenyl-2-(2-pyridyl)phenolatritium (abbreviation: LiPPP), lithium oxide (LiO ｘ Alkali metals such as cesium carbonate, alkaline earth metals, or compounds thereof can be used. The electron injection layer may also be a multilayer structure of two or more layers. For example, a multilayer structure in which lithium fluoride is used as the first layer and ytterbium is provided as the second layer can be used.

[0390] The electron injection layer may contain an electron-transporting material. For example, a compound having a lone pair of electrons and an electron-deficient heteroaromatic ring can be used as the electron-transporting material. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), or a triazine ring can be used.

[0391] Furthermore, the LUMO level of organic compounds containing lone pairs of electrons is preferably between -3.6 eV and -2.3 eV. In general, the highest occupied molecular orbital (HOMO) level and the LUMO level of organic compounds can be estimated by methods such as cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy.

[0392] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviated as TmPPPyTz), etc., can be used in organic compounds containing lone pairs of electrons. Compared to BPhen, NBPhen has a higher glass transition temperature (Tg) and superior heat resistance.

[0393] The charge generation layer preferably has a P-type layer. The P-type layer preferably contains an acceptor material, and preferably contains, for example, a hole transport material and an acceptor material applicable to the hole injection layer described above.

[0394] Furthermore, the charge generation layer preferably includes a layer containing a material with high electron injection properties. This layer can also be called an electron injection buffer layer or an N-type layer. The electron injection buffer layer is preferably provided between the P-type layer and the electron transport layer. By providing an electron injection buffer layer, the injection barrier between the P-type layer and the electron transport layer can be relaxed, allowing electrons generated in the P-type layer to be easily injected into the electron transport layer.

[0395] The electron injection buffer layer preferably contains an alkali metal or an alkaline earth metal, for example, a compound of an alkali metal or an alkaline earth metal. Specifically, the electron injection buffer layer preferably has an inorganic compound containing an alkali metal and oxygen, or an inorganic compound containing an alkaline earth metal and oxygen, and an inorganic compound containing lithium and oxygen (lithium oxide (Li ２ It is more preferable to have (O), etc. In addition, the electron injection buffer layer can suitably use materials applicable to the electron injection layer described above.

[0396] The charge generation layer preferably has a layer containing a material with high electron transport properties. This layer can also be called an electron relay layer. The electron relay layer is preferably provided between the P-type layer and the electron injection buffer layer. If the charge generation layer does not have an electron injection buffer layer, the electron relay layer is preferably provided between the P-type layer and the electron transport layer. The electron relay layer has the function of preventing interaction between the P-type layer and the electron injection buffer layer (or electron transport layer) and smoothly transferring electrons.

[0397] As the electron relay layer, it is preferable to use a phthalocyanine-based material such as copper(II) phthalocyanine (abbreviated as CuPc), or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0398] Furthermore, the P-type layer, electron injection buffer layer, and electron relay layer described above may not be clearly distinguishable depending on their cross-sectional shape or characteristics.

[0399] When stacking light-emitting units, the rise in driving voltage can be suppressed by providing a charge generation layer between the two light-emitting units.

[0400] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0401] (Embodiment 5) In this embodiment, an electronic device according to one aspect of the present invention will be described with reference to Figures 21 to 24.

[0402] The electronic device of this embodiment has a display panel (display device) according to one aspect of the present invention in its display unit. The display panel according to one aspect of the present invention is easily made high-definition and high-resolution, and can achieve high display quality. Therefore, it can be used in the display units of various electronic devices.

[0403] Examples of electronic devices include television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as other electronic devices with relatively large screens, digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, and audio playback devices.

[0404] In particular, a display panel according to one embodiment of the present invention can be used suitably in electronic devices having a relatively small display area because it can increase the resolution. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), as well as wearable devices that can be worn on the head, such as VR devices such as head-mounted displays, AR devices such as glasses, and MR (Mixed Reality) devices.

[0405] A display panel according to one embodiment of the present invention preferably has an extremely high resolution such as HD (1280 x 720 pixels), FHD (1920 x 1080 pixels), WQHD (2560 x 1440 pixels), WQXGA (2560 x 1600 pixels), 4K (3840 x 2160 pixels), or 8K (7680 x 4320 pixels). In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (resolution) of the display panel according to one embodiment of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 7000 ppi or more. By using a display panel having either high resolution or high detail, or both, it becomes possible to further enhance the sense of presence and depth. Furthermore, there are no particular limitations on the aspect ratio of the display panel in one embodiment of the present invention. For example, the display panel can support various aspect ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0406] The electronic device of this embodiment may have sensors (including those with the function of detecting, detecting, or measuring force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation).

[0407] The electronic device of this embodiment can have a variety of functions. For example, it can have a function to display various information (still images, videos, text images, etc.) on the display unit, a touch panel function, a function to display a calendar, date or time, a function to execute various software (programs), a wireless communication function, a function to read programs or data recorded on a recording medium, and so on.

[0408] Figures 21A to 21D illustrate an example of a wearable device that can be worn on the head. These wearable devices have one or both functions: the ability to display AR content and / or VR content. In addition to AR and VR, these wearable devices may also have the ability to display SR (Substantial Reality) or MR content. By having an electronic device that has the ability to display at least one of the following content types, such as AR, VR, SR, and MR, it is possible to enhance the user's sense of immersion.

[0409] The electronic device 700A shown in Figure 21A and the electronic device 700B shown in Figure 21B each include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0410] A display panel according to one embodiment of the present invention can be applied to the display panel 751. Therefore, an electronic device capable of displaying extremely high resolution can be created.

[0411] Electronic devices 700A and 700B can project an image displayed on the display panel 751 onto the display area 756 of the optical element 753. Because the optical element 753 is translucent, the user can see the image displayed on the display area superimposed on the transmitted image visible through the optical element 753. Therefore, electronic devices 700A and 700B are electronic devices capable of AR display.

[0412] Electronic devices 700A and 700B may be equipped with cameras capable of capturing images of the area in front of them as imaging units. Furthermore, electronic devices 700A and 700B may each be equipped with acceleration sensors such as gyro sensors to detect the orientation of the user's head and display an image corresponding to that orientation in the display area 756.

[0413] The communications unit has a wireless communication device, which can supply video signals and the like. Alternatively, instead of the wireless communication device, or in addition to the wireless communication device, it may be equipped with a connector to which a cable supplying video signals and power potential can be connected.

[0414] Furthermore, electronic devices 700A and 700B are equipped with batteries (not shown) that can be charged wirelessly, wired, or both.

[0415] The housing 721 may be equipped with a touch sensor module. The touch sensor module has the function of detecting when the outer surface of the housing 721 is touched. The touch sensor module can detect the user's tap or slide operations and perform various processes. For example, a tap operation can be used to pause or resume the video, and a slide operation can be used to fast forward or rewind. Furthermore, by providing a touch sensor module in each of the two housings 721, the range of operations can be expanded.

[0416] Various types of touch sensors can be applied to the touch sensor module. For example, various methods such as capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, and optical sensors can be used. In particular, it is preferable to apply a capacitive or optical sensor to the touch sensor module.

[0417] When using an optical touch sensor, a photoelectric conversion device (also called a photoelectric element) can be used as the light-receiving device (also called a photoelectric element). The active layer of the photoelectric conversion device can be made of either an inorganic semiconductor or an organic semiconductor, or both.

[0418] The electronic device 800A shown in Figure 21C and the electronic device 800B shown in Figure 21D each include a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0419] A display panel according to one embodiment of the present invention can be applied to the display unit 820. Therefore, an electronic device capable of displaying extremely high resolution can be created. This allows the user to experience a high level of immersion.

[0420] The display unit 820 is located inside the housing 821 in a position visible through the lens 832. Furthermore, by displaying different images on a pair of display units 820, a three-dimensional display using parallax can be achieved.

[0421] Electronic devices 800A and 800B can each be described as electronic devices for VR. A user wearing electronic device 800A or electronic device 800B can view the image displayed on the display unit 820 through the lens 832.

[0422] It is preferable that electronic devices 800A and 800B each have a mechanism that allows adjustment of the left and right positions of the lens 832 and the display unit 820 so that they are in the optimal position according to the user's eye position. It is also preferable that they have a mechanism that adjusts the focus by changing the distance between the lens 832 and the display unit 820.

[0423] The attachment portion 823 allows the user to attach the electronic device 800A or 800B to their head. While the attachment portion 823 is exemplified in Figure 21C and other figures as resembling the temples (or arms) of eyeglasses, it is not limited to this shape. The attachment portion 823 only needs to be wearable by the user; for example, it may be helmet-shaped or band-shaped.

[0424] The imaging unit 825 has the function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used in the imaging unit 825. In addition, multiple cameras may be provided to accommodate multiple angles of view, such as telephoto and wide-angle.

[0425] Although an example with an imaging unit 825 is shown here, any distance measuring sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object can be provided. In other words, the imaging unit 825 is one form of the detection unit. As the detection unit, for example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging) can be used. By using the image obtained by the camera and the image obtained by the distance image sensor, more information can be acquired, enabling more accurate gesture control.

[0426] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone. For example, a configuration having such a vibration mechanism can be applied to one or more of the display unit 820, housing 821, and mounting unit 823. This allows users to enjoy video and audio simply by wearing the electronic device 800A, without needing separate audio equipment such as headphones, earphones, or speakers.

[0427] Electronic devices 800A and 800B may each have input terminals. Cables can be connected to the input terminals to supply video signals from video output devices, etc., and power for charging batteries provided in the electronic devices.

[0428] An electronic device according to one aspect of the present invention may have a function for wireless communication with an earphone 750. The earphone 750 has a communication unit (not shown) and has a wireless communication function. The earphone 750 can receive information (e.g., voice data) from the electronic device through its wireless communication function. For example, the electronic device 700A shown in Figure 21A has a function for transmitting information to the earphone 750 through its wireless communication function. Also, for example, the electronic device 800A shown in Figure 21C has a function for transmitting information to the earphone 750 through its wireless communication function.

[0429] Furthermore, the electronic device may have an earphone section. The electronic device 700B shown in Figure 21B has an earphone section 727. For example, the earphone section 727 and the control unit can be connected to each other by a wire. Part of the wiring connecting the earphone section 727 and the control unit may be located inside the housing 721 or the mounting section 723.

[0430] Similarly, the electronic device 800B shown in Figure 21D has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be connected to each other by a wire. Part of the wiring connecting the earphone unit 827 and the control unit 824 may be located inside the housing 821 or the mounting unit 823. Also, the earphone unit 827 and the mounting unit 823 may have magnets. This allows the earphone unit 827 to be fixed to the mounting unit 823 by magnetic force, which is preferable as it facilitates storage.

[0431] Furthermore, the electronic device may have an audio output terminal to which earphones or headphones can be connected. The electronic device may also have an audio input terminal and / or an audio input mechanism. For example, a sound-collecting device such as a microphone can be used as the audio input mechanism. By having an audio input mechanism, the electronic device may be given the function of a so-called headset.

[0432] Thus, as one embodiment of the present invention, both eyeglass-type (electronic devices 700A and 700B, etc.) and goggle-type (electronic devices 800A and 800B, etc.) are preferred as electronic devices.

[0433] The electronic device 6500 shown in Figure 22A is a portable information terminal that can be used as a smartphone.

[0434] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0435] A display panel according to one embodiment of the present invention can be applied to the display unit 6502.

[0436] FIG. 22B is a schematic cross-sectional view including an end portion on the microphone 6506 side of the housing 6501.

[0437] A protective member 6510 having translucency is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are arranged in a space surrounded by the housing 6501 and the protective member 6510.

[0438] The display panel 6511, the optical member 6512, and the touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

[0439] In a region outside the display unit 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded-back portion. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on the printed circuit board 6517.

[0440] The display device according to an aspect of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. Further, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted while suppressing the thickness of the electronic device. Further, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, an electronic device with a narrow bezel can be realized.

[0441] An example of a television device is shown in FIG. 22C. The television device 7100 has a display unit 7000 incorporated in a housing 7101. Here, a configuration in which the housing 7101 is supported by a stand 7103 is shown.

[0442] The television device 7100 shown in Figure 22C can be operated using the operation switches on the housing 7101 and a separate remote control unit 7111. Alternatively, the display unit 7000 may be equipped with a touch sensor, and the television device 7100 can be operated by touching the display unit 7000 with a finger or the like. The remote control unit 7111 may have a display unit that displays information output from the remote control unit 7111. Channels and volume can be controlled and the image displayed on the display unit 7000 can be controlled using the operation keys or touch panel on the remote control unit 7111.

[0443] The television system 7100 is configured to include a receiver and a modem. The receiver can receive general television broadcasts. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0444] Figure 22D shows an example of a notebook personal computer. The notebook personal computer 7200 has a casing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. A display unit 7000 is incorporated into the casing 7211.

[0445] Figures 22E and 22F show examples of digital signage.

[0446] The digital signage 7300 shown in Figure 22E includes a housing 7301, a display unit 7000, and a speaker 7303, etc. Furthermore, it may include LED lamps, operation keys (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0447] Figure 22F shows a digital signage 7400 mounted on a cylindrical column 7401. The digital signage 7400 has a display unit 7000 that is provided along the curved surface of the column 7401.

[0448] The larger the display area 7000, the more information can be provided at once. Furthermore, a larger display area 7000 is more eye-catching, which can, for example, enhance the effectiveness of advertising.

[0449] Applying a touch panel to the display unit 7000 is preferable because it not only allows images or videos to be displayed on the display unit 7000, but also enables intuitive operation by the user. Furthermore, when used for purposes such as providing route information or traffic information, intuitive operation can enhance usability.

[0450] Furthermore, as shown in Figures 22E and 22F, it is preferable that the digital signage 7300 or digital signage 7400 can be linked wirelessly with an information terminal 7311 or information terminal 7411 such as a smartphone owned by the user. For example, the advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or information terminal 7411. Also, the display on the display unit 7000 can be switched by operating the information terminal 7311 or information terminal 7411.

[0451] Furthermore, the digital signage 7300 or digital signage 7400 can be used to run games using the screen of the information terminal 7311 or information terminal 7411 as the control device (controller). This allows an unspecified number of users to participate in and enjoy the game simultaneously.

[0452] In Figures 22C to 22F, a display panel according to one embodiment of the present invention can be applied to the display unit 7000.

[0453] The electronic device shown in Figures 23A to 23G includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), connection terminals 9006, a sensor 9007 (including a function to detect, detect, or measure force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), a microphone 9008, etc.

[0454] The electronic devices shown in Figures 23A to 23G have various functions. For example, they may have functions to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date or time, a function to control processing by various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc. However, the functions of electronic devices are not limited to these and can have various functions. Electronic devices may have multiple display units. Furthermore, electronic devices may be equipped with a camera, etc., and have functions to capture still images or videos and save them to a recording medium (external or built into the camera), a function to display the captured images on a display unit, etc.

[0455] Details of the electronic equipment shown in Figures 23A to 23G will be explained below.

[0456] Figure 23A is a perspective view showing a personal digital information terminal (PDI) 9101. The PDI 9101 can be used, for example, as a smartphone. The PDI 9101 may also be equipped with a speaker 9003, connection terminals 9006, sensors 9007, etc. The PDI 9101 can also display text and image information on multiple surfaces. Figure 23A shows an example where three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of incoming emails, SNS messages, and phone calls, the subject of an email or SNS message, the sender's name, date and time, battery level, and signal strength. Alternatively, icons 9050 or the like may be displayed in the location where the information 9051 is displayed.

[0457] Figure 23B is a perspective view showing the personal digital assistant (PDA) 9102. The PDA 9102 has the function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, a user can check information 9053, which is displayed in a position that can be observed from above the PDA 9102, while the PDA 9102 is stored in the breast pocket of their clothing. The user can check the display without taking the PDA 9102 out of their pocket and decide, for example, whether or not to answer a call.

[0458] Figure 23C is a perspective view showing the tablet terminal 9103. The tablet terminal 9103 can run various applications, such as mobile phone calls, email, document viewing and creation, music playback, internet communication, and computer games. The tablet terminal 9103 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of the housing 9000. The left side of the housing 9000 has operation keys 9005 as buttons for operation, and the bottom has connection terminals 9006.

[0459] Figure 23D is a perspective view showing a wristwatch-type personal information terminal 9200. The personal information terminal 9200 can be used, for example, as a smartwatch (registered trademark). The display unit 9001 has a curved display surface, allowing it to display information along the curved surface. The personal information terminal 9200 can also make hands-free calls by communicating with, for example, a wireless communication headset. Furthermore, the personal information terminal 9200 can transmit data to other information terminals and be charged via a connection terminal 9006. Charging may be performed by wireless power supply.

[0460] Figures 23E to 23G are perspective views showing a foldable portable information terminal 9201. Figure 23E shows the portable information terminal 9201 in an unfolded state, Figure 23G shows it in a folded state, and Figure 23F shows a perspective view of the state in between, transitioning from one of Figures 23E or 23G to the other. The portable information terminal 9201 offers excellent portability in its folded state and excellent readability of the display due to its seamless, wide display area in its unfolded state. The display unit 9001 of the portable information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm to 150 mm.

[0461] This embodiment can be implemented in appropriate combination with other embodiments described herein, at least in part.

[0462] Figures 24A and 24B show the external appearance of the head-mounted display 8300. The head-mounted display 8300 includes a housing 8301, a display unit 8302, a band-shaped fixing device 8304, and a pair of lenses 8305.

[0463] The user can view the display on the display unit 8302 through the lens 8305. It is preferable to arrange the display unit 8302 in a curved shape, as this allows the user to experience a greater sense of presence. Furthermore, by viewing different images displayed in different areas of the display unit 8302 through the lens 8305, three-dimensional display using parallax can be performed. Note that the configuration is not limited to having one display unit 8302; two display units 8302 may be provided, with one display unit for each of the user's eyes.

[0464] A display device according to one embodiment of the present invention can be applied to the display unit 8302. The display device according to one embodiment of the present invention can also achieve extremely high resolution. Therefore, even when the display is magnified and viewed using the lens 8305, the pixels are difficult for the user to see. In other words, the display unit 8302 can be used to allow the user to view a highly realistic image.

[0465] Furthermore, it is preferable that the head-mounted display 8300 has head tracking and eye tracking functions. This allows the displayed image to move in accordance with the user's movements and the direction of the user's gaze. This makes it possible to present the user with highly immersive images. For example, as shown in Figure 24C, a passenger in the back seat of a car can wear the head-mounted display 8300. In this case, because the image moves in sync with the shaking of the car body and the gaze is not fixed, motion sickness can be reduced compared to viewing images on a smartphone or tablet device, for example.

[0466] HT: Processing room, LL: Loading room, RBT: Transport robot, SP: Film deposition room, TF: Transport room, UL: Unloading room, 100: Display device, 101: Substrate, 110B: Light-emitting element, 110G: Light-emitting element, 110R: Light-emitting element, 111B: Pixel electrode, 111G: Pixel electrode, 111R: Pixel electrode, 112B: First EL layer, 112G: First EL layer, 112R: First EL layer, 112aB: Layer, 112aBf: Film, 112aG: Layer, 112aGf: Film, 112aR: Layer, 112bB: Layer, 112bBf: Film, 112bG: Layer, 112bGf: Film, 112bR: Layer, 112gB: Layer ,112hB: layer, 112gG: layer, 112hG: layer, 112gR: layer, 112hR: layer, 114B: second EL layer, 114Bf: film, 114G: second EL layer, 114Gf: film, 114R: second EL layer, 115: upper electrode, 120: partition, 120f: conductive film, 121: film deposition material, 122: film deposition material, 125: rotation axis, 131: insulating layer, 132: insulating layer, 133: insulating layer, 135: protective layer, 150: transistor, 151: semiconductor layer, 152: insulating layer, 153: conductive layer, 154: conductive layer, 198B: resist mask, 198G: resist mask, 198 M: Resist mask, 199B: Insulating layer, 199Bf: Insulating film, 199G: Insulating layer, 199Gf: Insulating film, 199R: Insulating layer, 201: Transistor, 202: Transistor, 204: Connection, 205: Transistor, 209: Transistor, 210: Transistor, 211: Insulating layer, 212: Insulating layer, 213: Insulating layer, 214: Insulating layer, 215: Insulating layer, 218: Insulating layer, 221: Conductive layer, 222a: Conductive layer, 222b: Conductive layer, 223: Conductive layer, 225: Insulating layer, 228: Region, 231: Semiconductor layer, 231i: Channel formation region, 231n: Low resistance region Area, 240: Capacitance, 241: Conductive layer, 242: Connection layer, 243: Insulating layer, 245: Conductive layer, 251: Conductive layer, 252: Conductive layer, 254: Insulating layer, 255: Insulating layer, 256: Plug, 261: Insulating layer, 262: Insulating layer, 263: Insulating layer, 264: Insulating layer, 265: Insulating layer, 271: Plug, 274: Plug, 274a: Conductive layer, 274b: Conductive layer, 280: Display module, 281: Display section, 282: Circuit section, 283: Pixel circuit section, 283a: Pixel circuit, 284: Pixel section, 284a: Pixel, 285: Terminal section, 286: Wiring section, 290: FPC, 291: Substrate,292: Substrate, 301: Substrate, 310: Transistor, 311: Conductive layer, 312: Low resistance region, 313: Insulating layer, 314: Insulating layer, 315: Element isolation layer, 320: Transistor, 321: Semiconductor layer, 323: Insulating layer, 324: Conductive layer, 325: Conductive layer, 326: Insulating layer, 327: Conductive layer, 328: Insulating layer, 329: Insulating layer, 331: Substrate, 332: Insulating layer, 400A: Display device, 400B: Display device, 400C: Display device, 400D: Display device, 400E: Display device, 401: Substrate, 411a: Pixel electrode, 411b: Pixel electrode, 411c: Pixel electrode, 41 2a: layer, 412b: layer, 412c: layer, 413a: layer, 413b: layer, 413c: layer, 414: upper electrode, 416: protective layer, 417: light-shielding layer, 419: resin layer, 420: partition, 421: insulating layer, 426a: optical adjustment layer, 426b: optical adjustment layer, 426c: optical adjustment layer, 430a: light-emitting element, 430b: light-emitting element, 430c: light-emitting element, 442: adhesive layer, 443: space, 451: substrate, 452: substrate, 453: substrate, 454: substrate, 455: adhesive layer, 462: display unit, 464: circuit, 465: wiring, 466: conductive layer, 472: FPC, 473: IC, 700 A: Electronic device, 700B: Electronic device, 721: Housing, 723: Mounting part, 727: Earphone part, 750: Earphone, 751: Display panel, 753: Optical component, 756: Display area, 757: Frame, 758: Nose pad, 761: Lower electrode, 762: Upper electrode, 763: EL layer, 763a: Light-emitting unit, 763b: Light-emitting unit, 763c: Light-emitting unit, 764: Layer, 771: Light-emitting layer, 771a: Light-emitting layer, 771b: Light-emitting layer, 771c: Light-emitting layer, 772: Light-emitting layer, 772a: Light-emitting layer, 772b: Light-emitting layer, 772c: Light-emitting layer, 773: Light-emitting layer, 780: Layer, 780a: layer, 780b: layer, 780c: layer, 781: layer, 782: layer, 785: charge generation layer, 790: layer, 790a: layer, 790b: layer, 790c: layer, 791: layer, 792: layer, 800A: electronic equipment, 800B: electronic equipment, 820: display unit, 821: housing, 822: communication unit, 823: mounting unit, 824: control unit, 825: imaging unit, 827: earphone unit, 832: lens, 6500: electronic equipment, 6501: housing, 6502: display unit, 6503: power button, 6504: button, 6505: speaker, 6506: microphone, 6507: camera, 6508: light source,6510: Protective component, 6511: Display panel, 6512: Optical component, 6513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Printed circuit board, 6518: Battery, 7000: Display unit, 7100: Television equipment, 7101: Enclosure, 7103: Stand, 7111: Remote control unit, 7200: Notebook personal computer, 7211: Enclosure, 7212: Keyboard, 7213: Pointing device, 7214: External connection port, 7300: Digital signage, 7301: Enclosure, 7303: Speaker, 7311: Information terminal, 7400: Digital signage Page, 7401: Pillar, 7411: Information terminal, 8300: Head-mounted display, 8301: Housing, 8302: Display unit, 8304: Fixing device, 8305: Lens, 9000: Housing, 9001: Display unit, 9002: Camera, 9003: Speaker, 9005: Operation key, 9006: Connection terminal, 9007: Sensor, 9008: Microphone, 9050: Icon, 9051: Information, 9052: Information, 9053: Information, 9054: Information, 9055: Hinge, 9101: Portable information terminal, 9102: Portable information terminal, 9103: Tablet terminal, 9200: Portable information terminal, 9201: Portable information terminal,

Claims

It comprises a first light-emitting element, a second light-emitting element, and a partition wall located between the first light-emitting element and the second light-emitting element. The first light-emitting element comprises a first pixel electrode, a first EL layer on the first pixel electrode, and an upper electrode. The second light-emitting element comprises a second pixel electrode, a second EL layer on the second pixel electrode, and the upper electrode. The upper electrode covers the upper surface of the first EL layer and the upper surface of the second EL layer, and is in contact with the side surface of the partition wall. Display device. 　 In claim 1, The first EL layer comprises a first layer and a second layer on the first layer. The first layer includes a hole injection layer, The second layer comprises the first luminescent compound, The end of the first layer is located inward from the end of the second layer. The second EL layer comprises a second luminescent compound. Display device. 　 In claim 1, The first EL layer comprises a first layer, a second layer on the first layer, and a charge generating layer located between the first layer and the second layer. The first layer comprises a first luminescent compound, The second layer comprises a second luminescent compound, The end of the charge generation layer is located inward from the end of the second layer. The second EL layer comprises a third luminescent compound. Display device. 　 In claim 3, The first luminescent compound and the second luminescent compound are compounds that emit light of the same color. Display device. 　 In claim 3, The first luminescent compound and the second luminescent compound are compounds that emit light of different colors. Display device. 　 In claim 1, The partition wall has an inverse tapered shape in cross-section and is conductive. Display device. 　 In claim 1, Having a first insulating layer, The first insulating layer is located between the first pixel electrode and the second pixel electrode. The partition wall is in contact with the upper surface of the first insulating layer, The angle between the contact surface of the partition wall and the first insulating layer and the side surface is 95 degrees or more and 150 degrees or less. Display device. 　 In claim 1, Having a first insulating layer, The ends of the first pixel electrode and the ends of the second pixel electrode are each covered with the first insulating layer. The partition wall is located on the first insulating layer, The first EL layer is in contact with the upper surface of the first pixel electrode and the upper surface of the first insulating layer. The second EL layer is in contact with the upper surface of the second pixel electrode and the upper surface of the first insulating layer. The upper electrode is in contact with the upper surface of the first insulating layer. Display device. 　 In claim 1, The partition wall contains oxygen and indium. Display device. 　 In claim 1, It has a transistor, The transistor is located below the first pixel electrode and is connected to the first pixel electrode. Display device. 　 In claim 1, It has a transistor, The transistor is located below the first pixel electrode and is connected to the first pixel electrode. The transistor includes a metal oxide in the semiconductor layer where the channel is formed. Display device. 　 A first pixel electrode and a second pixel electrode are formed on the substrate. A first conductive film is formed on the first pixel electrode and the second pixel electrode. A first mask is formed on the first conductive film. By removing a portion of the first conductive film by wet etching using the first mask, a partition wall is formed between the first pixel electrode and the second pixel electrode. A first film is formed on the first pixel electrode, the second pixel electrode, and the partition wall using a vapor deposition method. The formation of the first film is carried out such that the material flies at a first angle with respect to the direction perpendicular to the surface to be formed. A second film is formed on the first film using a vapor deposition method. The formation of the second film is carried out such that the material flies at a second angle with respect to the vertical direction. A second mask is formed on the second film. The second mask is formed to overlap with the first pixel electrode, By using the second mask, a portion of the second film and a portion of the first film are removed to form the first EL layer. A second EL layer is formed on the second pixel electrode. An upper electrode is formed on the first EL layer, on the second EL layer, and in contact with the side surface of the partition wall using a vapor deposition method. The formation of the upper electrode is carried out such that the material flies at a third angle with respect to the vertical direction. The aforementioned first angle is 0 degrees or greater, The second angle is greater than the first angle. The third angle is greater than the second angle. Method for manufacturing a display device. 　 In claim 12, A third film is formed using a vapor deposition method in which the material flies at the first angle with respect to the vertical direction. A fourth film is formed using a vapor deposition method such that the material flies at the second angle with respect to the vertical direction. The second EL layer is formed by processing the third and fourth films. Method for manufacturing a display device.

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