Display device, display module, and electronic apparatus

Abstract

The present invention provides a novel display device having superior convenience, usability, or reliability. The display device includes a first light-emitting device, a second light-emitting device, a first insulating layer, and a second insulating layer. The first light-emitting device has a first pixel electrode, a common electrode, and a first intermediate layer, the first intermediate layer including a first inorganic compound and a first organic compound, the first organic compound comprising a pair of unshared electron pairs, and the first organic compound interacting with the first inorganic compound and forming a half-filled orbital. The second light-emitting device has a second pixel electrode, a common electrode, and a second intermediate layer, the second intermediate layer including a first inorganic compound and a first organic compound. The first insulating layer covers a portion of the upper surface and the side surface of the first intermediate layer, and covers a portion of the upper surface and the side surface of the second intermediate layer. The second insulating layer overlaps, via the first insulating layer, the portion of the upper surface and the side surface of the first intermediate layer and the portion of the upper surface and the side surface of the second intermediate layer.

Description

Display device, display module and electronic device

[0001] One embodiment of the present invention relates to a display device, a display module, and an electronic device.

[0002] One embodiment of the present invention is not limited to the above technical field, and examples of the technical field of one embodiment of the present invention include semiconductor devices, display devices, light-emitting devices, power storage devices, memory devices, electronic devices, lighting devices, input devices (e.g., touch sensors), input / output devices (e.g., touch panels), driving methods thereof, and manufacturing methods thereof.

[0003] In recent years, display devices have been expected to be used in a variety of applications. For example, applications of large display devices include home television devices (also called televisions or television receivers), digital signage, and public information displays (PIDs). In addition, development of mobile information terminals, such as smartphones and tablet terminals equipped with touch panels, is progressing.

[0004] There is also a demand for higher definition display devices. Devices requiring high-definition display devices, such as devices for virtual reality (VR), augmented reality (AR), substitutional reality (SR), and mixed reality (MR), are being actively developed.

[0005] As a display device, for example, a light-emitting device having a light-emitting device (also referred to as a light-emitting element) has been developed. A light-emitting device (also referred to as an EL device or an EL element) utilizing an electroluminescence (hereinafter referred to as EL) phenomenon has features such as being easily thin and lightweight, being capable of high-speed response to an input signal, and being capable of being driven by a DC constant voltage power supply, and is therefore applied to a display device.

[0006] Patent Document 1 discloses a display device for VR using an organic EL device (also called an organic EL element). Patent Document 2 discloses a light-emitting device with low driving voltage and good reliability, which uses a mixed film of a transition metal and an organic compound having an unshared electron pair as an electron injection layer.

[0007] International Publication No. 2018 / 087625 Japanese Patent Application Laid-Open No. 2018-201012

[0008] An object of one embodiment of the present invention is to provide a display device with high display quality. Another object of one embodiment of the present invention is to provide a high-resolution display device. Another object of one embodiment of the present invention is to provide a highly reliable display device. Another object of one embodiment of the present invention is to provide a novel display device with excellent convenience, usefulness, or reliability. Another object of one embodiment of the present invention is to provide a novel display module with excellent convenience, usefulness, or reliability. Another object of one embodiment of the present invention is to provide a novel electronic device with excellent convenience, usefulness, or reliability. Another object is to provide a novel display device, a novel display module, a novel electronic device, or a novel semiconductor device.

[0009] Note that the description of these problems does not preclude the existence of other problems. One embodiment of the present invention does not necessarily have to solve all of these problems. Problems other than these can be extracted from the description in the specification, drawings, and claims.

[0010] (1) One embodiment of the present invention is a display device including a first light-emitting device, a second light-emitting device, a first insulating layer, and a second insulating layer.

[0011] The first light-emitting device has a first pixel electrode, a common electrode, and a first intermediate layer, the first intermediate layer being sandwiched between the common electrode and the first pixel electrode, the first intermediate layer having a first layer and a second layer, the second layer being sandwiched between the first layer and the first pixel electrode.

[0012] The second layer includes a first inorganic compound and a first organic compound, the first organic compound having an unshared electron pair, and the first organic compound interacts with the first inorganic compound to form a half-occupied orbital.

[0013] The second light-emitting device has a second pixel electrode, a common electrode, and a second intermediate layer, the second intermediate layer being sandwiched between the common electrode and the second pixel electrode, the second intermediate layer having a third layer and a fourth layer, the fourth layer being sandwiched between the third layer and the second pixel electrode.

[0014] The fourth layer includes a first inorganic compound and a first organic compound.

[0015] The first insulating layer covers part of the top surface and the side surface of the first intermediate layer and part of the top surface and the side surface of the second intermediate layer.

[0016] The second insulating layer overlaps with a part of the upper surface and a side surface of the first intermediate layer and a part of the upper surface and a side surface of the second intermediate layer through the first insulating layer, and the upper surface of the second insulating layer is covered with the common electrode.

[0017] In a cross-sectional view, the end of the second insulating layer has a tapered shape with a taper angle of less than 90°, and the second insulating layer covers at least a part of the side surface of the first insulating layer.

[0018] (2) Another embodiment of the present invention is a display device including a first light-emitting device, a second light-emitting device, a first insulating layer, and a second insulating layer.

[0019] The first light-emitting device has a first pixel electrode, a common electrode, a first unit, a second unit, and a first intermediate layer. The first unit is sandwiched between the common electrode and the first pixel electrode, the second unit is sandwiched between the common electrode and the first unit, and the first intermediate layer is sandwiched between the first unit and the second unit. The first intermediate layer has a first layer and a second layer, and the second layer is sandwiched between the first layer and the first unit.

[0020] The second layer includes a first inorganic compound and a first organic compound, the first organic compound having an unshared electron pair, and the first organic compound interacts with the first inorganic compound to form a half-occupied orbital.

[0021] The second light-emitting device has a second pixel electrode, a common electrode, a third unit, a fourth unit, and a second intermediate layer. The third unit is sandwiched between the common electrode and the second pixel electrode, the fourth unit is sandwiched between the common electrode and the third unit, and the second intermediate layer is sandwiched between the fourth unit and the third unit. The second intermediate layer has a third layer and a fourth layer, and the fourth layer is sandwiched between the third layer and the third unit.

[0022] The fourth layer includes a first inorganic compound and a first organic compound, and the first unit, the second unit, the third unit, and the fourth unit each include a light-emitting material.

[0023] The first insulating layer covers a portion of the top surface and a side surface of the second unit and a portion of the top surface and a side surface of the fourth unit, and the second insulating layer overlaps with a portion of the top surface and a side surface of the second unit and a portion of the top surface and a side surface of the fourth unit via the first insulating layer, and the top surface of the second insulating layer is covered by the common electrode.

[0024] In a cross-sectional view, the end of the second insulating layer has a tapered shape with a taper angle of less than 90°, and the second insulating layer covers at least a part of the side surface of the first insulating layer.

[0025] This forms a gap between the first intermediate layer and the second intermediate layer. A first insulating layer is formed along the gap. The first insulating layer and the second insulating layer can suppress current flowing between the first intermediate layer and the second intermediate layer. Furthermore, the occurrence of crosstalk between the first light-emitting device and the second light-emitting device can be suppressed. As a result, a novel display device with excellent convenience, usefulness, and reliability can be provided.

[0026] (3) In one embodiment of the present invention, the second layer contains unpaired electrons, and the unpaired electrons are measured by an electron spin resonance (ESR) apparatus to determine a ratio of 1×10 １６ spins / cm ３ 1x10 or more １８ spins / cm ３This is a display device that can be observed at the following spin densities.

[0027] (4) Another aspect of the present invention is a display device in which the unpaired electron has a g value in the range of 2.003 to 2.004.

[0028] (5) Another embodiment of the present invention is a display device in which the first organic compound has an electron-deficient heteroaromatic ring.

[0029] This allows for a wider range of processing options to be selected after the second layer is formed. Furthermore, after the first layer is formed on the second layer, the first layer and the second layer can be processed into a predetermined shape, for example, by photolithography. Furthermore, after the second unit is formed, the second unit and the second layer can be processed into a predetermined shape, for example, by photolithography. Furthermore, for example, the second light-emitting device can be formed adjacent to the first light-emitting device, separate from it, without using a fine metal mask. As a result, a novel display device with excellent convenience, usefulness, and reliability can be provided.

[0030] (6) Another embodiment of the present invention is a display device in which the first organic compound has a lowest unoccupied molecular orbital (LUMO) level in the range of −3.6 eV to −2.3 eV.

[0031] (7) Another embodiment of the present invention is a display device in which the first inorganic compound contains a metal element and oxygen.

[0032] (8) Another embodiment of the present invention is a display device in which the first inorganic compound contains lithium and oxygen.

[0033] This makes it possible to reduce the drive voltage of the first light-emitting device and the power consumption of the display device, thereby providing a novel display device that is highly convenient, useful, and reliable.

[0034] (9) Another embodiment of the present invention is a display device in which the first layer contains a material having an electron-accepting property.

[0035] (10) Another embodiment of the present invention is a display device including a first light-emitting device, a second light-emitting device, a first insulating layer, and a second insulating layer.

[0036] The first light-emitting device has a first pixel electrode, a common electrode, and a first intermediate layer, the first intermediate layer being sandwiched between the common electrode and the first pixel electrode, the first intermediate layer having a first layer and a second layer, the first layer being sandwiched between the common electrode and the second layer.

[0037] The first layer includes a material having electron accepting properties, and the first layer has a concentration of 1×10 ２ [Ω・cm] or more 1×10 ８ It has an electrical resistivity of [Ω·cm] or less.

[0038] The second light-emitting device has a second pixel electrode, a common electrode, and a second intermediate layer, the second intermediate layer being sandwiched between the common electrode and the second pixel electrode, the second intermediate layer having a third layer and a fourth layer, the third layer being sandwiched between the common electrode and the fourth layer.

[0039] The third layer includes a material having electron accepting properties.

[0040] The first insulating layer covers part of the top surface and the side surface of the first intermediate layer and part of the top surface and the side surface of the second intermediate layer.

[0041] The second insulating layer overlaps with a part of the upper surface and a side surface of the first intermediate layer and a part of the upper surface and a side surface of the second intermediate layer through the first insulating layer, and the upper surface of the second insulating layer is covered with the common electrode.

[0042] In a cross-sectional view, the end of the second insulating layer has a tapered shape with a taper angle of less than 90°, and the second insulating layer covers at least a part of the side surface of the first insulating layer.

[0043] (11) Another embodiment of the present invention is a display device in which an end portion of the second insulating layer is located outside an end portion of the first insulating layer.

[0044] (12) Another embodiment of the present invention is a display device in which the second insulating layer has a convex curved upper surface.

[0045] (13) Another embodiment of the present invention is a display device in which an end portion of the first insulating layer has a tapered shape with a taper angle of less than 90° in a cross-sectional view.

[0046] (14) Another embodiment of the present invention is a display device in which the second insulating layer has a concavely curved side surface.

[0047] (15) Another embodiment of the present invention is the above display device including a third insulating layer and a fourth insulating layer.

[0048] The third insulating layer is located between the top surface of the first intermediate layer and the first insulating layer, and the fourth insulating layer is located between the top surface of the second intermediate layer and the first insulating layer.

[0049] The end of the third insulating layer and the end of the fourth insulating layer are each located outside the end of the first insulating layer.

[0050] (16) Another embodiment of the present invention is a display device in which the second insulating layer covers at least part of a side surface of the third insulating layer and at least part of a side surface of the fourth insulating layer.

[0051] (17) Another embodiment of the present invention is a display device in which an end portion of the third insulating layer and an end portion of the fourth insulating layer each have a tapered shape with a taper angle of less than 90° in a cross-sectional view.

[0052] (18) Another embodiment of the present invention is a display device in which the first insulating layer and the second insulating layer each have a portion overlapping with a top surface of a first pixel electrode and a portion overlapping with a top surface of a second pixel electrode.

[0053] (19) Another embodiment of the present invention is a display device in which the first intermediate layer covers a side surface of the first pixel electrode, and the second intermediate layer covers a side surface of the second pixel electrode.

[0054] (20) Another embodiment of the present invention is a display device in which an end portion of the first pixel electrode and an end portion of the second pixel electrode each have a tapered shape with a taper angle of less than 90° in a cross-sectional view.

[0055] (21) Another embodiment of the present invention is a display device in which the first insulating layer is an inorganic insulating layer and the second insulating layer is an organic insulating layer.

[0056] (22) Another embodiment of the present invention is a display device in which the first insulating layer contains aluminum oxide.

[0057] (23) Another embodiment of the present invention is a display device in which the second insulating layer contains an acrylic resin.

[0058] (24) Another embodiment of the present invention is a display device in which the first light-emitting device has a fifth layer between the first intermediate layer and the common electrode, and the second light-emitting device has a fifth layer between the second intermediate layer and the common electrode, and the fifth layer is located between the second insulating layer and the common electrode.

[0059] (25) Another aspect of the present invention is a display module including the display device described above and at least one of a connector and an integrated circuit.

[0060] (26) Another embodiment of the present invention is an electronic device including the above-described display module and at least one of a housing, a battery, a camera, a speaker, and a microphone.

[0061] One embodiment of the present invention can provide a display device with high display quality. Another embodiment of the present invention can provide a high-resolution display device. Another embodiment of the present invention can provide a highly reliable display device. Another embodiment of the present invention can provide a novel display device with excellent convenience, usefulness, or reliability. Another embodiment of the present invention can provide a novel display module with excellent convenience, usefulness, or reliability. Another embodiment of the present invention can provide a novel electronic device with excellent convenience, usefulness, or reliability. Another embodiment of the present invention can provide a novel display device, a novel display module, a novel electronic device, or a novel semiconductor device.

[0062] Note that the description of these effects does not preclude the existence of other effects. One embodiment of the present invention does not necessarily have all of these effects. Effects other than these can be extracted from the description in the specification, drawings, and claims.

[0063] FIG. 1 is a cross-sectional view showing an example of a display device. FIG. 2 is a cross-sectional view showing an example of a display device. FIG. 3A is a top view showing an example of a display device. FIG. 3B is a cross-sectional view showing an example of a display device. FIGS. 4A and 4B are cross-sectional views showing an example of a display device. FIGS. 5A and 5B are cross-sectional views showing an example of a display device. FIGS. 6A and 6B are cross-sectional views showing an example of a display device. FIGS. 7A and 7B are cross-sectional views showing an example of a display device. FIGS. 8A and 8B are cross-sectional views showing an example of a display device. FIGS. 9A and 9B are cross-sectional views showing an example of a display device. FIG. 10A is a top view showing an example of a display device. FIG. 10B is a cross-sectional view showing an example of a display device. FIGS. 11A to 11C are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 12A to 12C are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 13A to 13C are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 14A and 14B are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 15A and 15B are cross-sectional views showing an example of a manufacturing method of a display device. FIGS. 16A to 16D are cross-sectional views showing an example of a method for manufacturing a display device. FIGS. 17A to 17F are views showing an example of a pixel. FIGS. 18A to 18K are views showing an example of a pixel. FIGS. 19A and 19B are perspective views showing an example of a display device. FIGS. 20A and 20B are cross-sectional views showing an example of a display device. FIGS. 21 are cross-sectional views showing an example of a display device. FIGS. 22 are cross-sectional views showing an example of a display device. FIG. 23 is a cross-sectional view showing an example of a display device. FIG. 24 is a cross-sectional view showing an example of a display device. FIG. 25 is a cross-sectional view showing an example of a display device. FIG. 26 is a perspective view showing an example of a display device. FIG. 27A is a cross-sectional view showing an example of a display device. FIGS. 27B and 27C are cross-sectional views showing an example of a transistor. FIGS. 28A to 28D are cross-sectional views showing an example of a display device. FIG. 29 is a cross-sectional view showing an example of a display device. FIGS. 30A to 30F are views showing a structural example of a light-emitting device. FIGS. 31A and 31B are views showing a structural example of a light-receiving device. FIGS. 31C to 31E are views showing a structural example of a display device. 32A to 32D are diagrams showing an example of an electronic device.33A to 33F are diagrams illustrating an example of an electronic device. FIGS. 34A to 34G are diagrams illustrating an example of an electronic device. FIGS. 35A to 35C are diagrams illustrating the configuration of a display device according to an example. FIGS. 36A and 36B are diagrams illustrating the configuration of a light-emitting device according to an example. FIG. 37 is a diagram illustrating the current density-luminance characteristics of a light-emitting device according to an example. FIG. 38 is a diagram illustrating the luminance-current efficiency characteristics of a light-emitting device according to an example. FIG. 39 is a diagram illustrating the voltage-luminance characteristics of a light-emitting device according to an example. FIG. 40 is a diagram illustrating the voltage-current characteristics of a light-emitting device according to an example. FIG. 41 is a diagram illustrating the emission spectrum of a light-emitting device according to an example.

[0064] The embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes can be made in form and detail without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0065] In the configuration of the invention described below, the same parts or parts having similar functions are denoted by the same reference numerals in different drawings, and repeated explanations thereof will be omitted. In addition, when referring to similar functions, the same hatch pattern may be used and no particular reference numeral may be assigned.

[0066] Furthermore, for ease of understanding, the position, size, range, etc. of each component shown in the drawings may not represent the actual position, size, range, etc. Therefore, the disclosed invention is not necessarily limited to the position, size, range, etc. disclosed in the drawings.

[0067] The terms "film" and "layer" can be interchangeable depending on the circumstances. For example, the term "conductive layer" can be changed to the term "conductive film." Or, for example, the term "insulating film" can be changed to the term "insulating layer."

[0068] In this specification, etc., a device fabricated using a metal mask or an FMM (fine metal mask, high-resolution metal mask) may be referred to as a device with an MM (metal mask) structure. Also, in this specification, etc., a device fabricated without using a metal mask or an FMM may be referred to as a device with an MML (metal maskless) structure.

[0069] In this specification and the like, holes or electrons may be referred to as "carriers." Specifically, a hole injection layer or an electron injection layer may be referred to as a "carrier injection layer," a hole transport layer or an electron transport layer may be referred to as a "carrier transport layer," and a hole block layer or an electron block layer may be referred to as a "carrier block layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier block layer may not be clearly distinguishable from each other depending on their cross-sectional shapes or characteristics. Furthermore, one layer may have two or three functions among the carrier injection layer, carrier transport layer, and carrier block layer.

[0070] In this specification and the like, a light-emitting device (light-emitting element) has an EL layer between a pair of electrodes. The EL layer has at least a light-emitting layer. In this specification and the like, a light-receiving device (also referred to as a light-receiving element) has at least an active layer that functions as a photoelectric conversion layer between a pair of electrodes. In this specification and the like, one of the pair of electrodes may be referred to as a pixel electrode, and the other as a common electrode.

[0071] In this specification, the term "tapered shape" refers to a shape in which at least a portion of the side surface of the structure is inclined relative to the substrate surface. For example, it is preferable to have a region in which the angle (also called the taper angle) between the inclined side surface and the substrate surface is less than 90°. The side surface of the structure and the substrate surface do not necessarily need to be completely flat, and may be approximately planar with a slight curvature or approximately planar with a slight unevenness.

[0072] A display device includes a first light-emitting device, a second light-emitting device, a first insulating layer, and a second insulating layer, wherein the first light-emitting device has a first pixel electrode, a common electrode, and a first intermediate layer, the first intermediate layer being sandwiched between the common electrode and the first pixel electrode, the first intermediate layer having a first layer and a second layer, the second layer being sandwiched between the first layer and the first pixel electrode, and the second layer including a first inorganic compound and a first organic compound, the first organic compound having an unshared electron pair, and the first organic compound interacting with the first inorganic compound to form a half-occupied orbital. The second light-emitting device has a second pixel electrode, a common electrode, and a second intermediate layer, the second intermediate layer is sandwiched between the common electrode and the second pixel electrode, the second intermediate layer has a third layer and a fourth layer, the fourth layer is sandwiched between the third layer and the second pixel electrode, and the fourth layer contains a first inorganic compound and a first organic compound. The first insulating layer covers a portion of the upper surface and side surfaces of the first intermediate layer and a portion of the upper surface and side surfaces of the second intermediate layer, the second insulating layer overlaps a portion of the upper surface and side surfaces of the first intermediate layer and a portion of the upper surface and side surfaces of the second intermediate layer via the first insulating layer, the upper surface of the second insulating layer is covered by the common electrode, and in a cross-sectional view, an end of the second insulating layer has a tapered shape with a taper angle of less than 90°, and the second insulating layer covers at least a portion of the side surfaces of the first insulating layer.

[0073] This makes it possible to suppress the current flowing between the first intermediate layer and the second intermediate layer. It also makes it possible to suppress the occurrence of crosstalk between the first light-emitting device and the second light-emitting device. It also makes it possible to suppress the driving voltage of the light-emitting device. It also makes it possible to suppress power consumption. As a result, it is possible to provide a novel display device that is excellent in convenience, usefulness, and reliability.

[0074] Embodiment 1 In this embodiment, a structure of a display device according to one embodiment of the present invention will be described with reference to FIGS.

[0075] FIG. 1 is a cross-sectional view illustrating a structure of a display device according to one embodiment of the present invention.

[0076] FIG. 2 is a cross-sectional view illustrating a structure of a light-emitting device that can be used for a display device according to one embodiment of the present invention.

[0077] 3A and 3B are a top view and a cross-sectional view illustrating an example of a display device according to one embodiment of the present invention.

[0078] <Configuration Example of Display Device> The display device described in this embodiment includes a light-emitting device 130a, a light-emitting device 130b, an insulating layer 125, and an insulating layer 127 (see FIG. 3B).

[0079] <<Configuration Example of Light-Emitting Device 130a>> The light-emitting device 130a includes a pixel electrode 111a, a common electrode 115, a unit 703a, a unit 703a2, and an intermediate layer 706a (see FIG. 1). The light-emitting device 130a also includes a layer 704a and a common layer 114. The light-emitting device 130a also includes a first layer 113a between the pixel electrode 111a and the common electrode 115 (see FIGS. 1 and 3B). The first layer 113a includes a unit 703a, a unit 703a2, an intermediate layer 706a, a layer 704a, and the common layer 114.

[0080] The unit 703a is sandwiched between the common electrode 115 and the pixel electrode 111a, and the unit 703a2 is sandwiched between the common electrode 115 and the unit 703a.

[0081] Intermediate layer 706a is sandwiched between unit 703a2 and unit 703a, and intermediate layer 706a has layers 706a1 and 706a2. Layer 706a2 is sandwiched between layer 706a1 and unit 703a.

[0082] The layer 706a2 includes a first inorganic compound and a first organic compound. The first organic compound has an unshared electron pair, and the first organic compound interacts with the first inorganic compound to form a half-occupied orbital.

[0083] <<Configuration Example of Light-Emitting Device 130b>> The light-emitting device 130b has a pixel electrode 111b, a common electrode 115, a unit 703b, a unit 703b2, and an intermediate layer 706b (see FIG. 1). The light-emitting device 130b also has a layer 704b and a common layer 114. The light-emitting device 130b also has a second layer 113b between the pixel electrode 111b and the common electrode 115 (see FIGS. 1 and 3B). The second layer 113b has a unit 703b, a unit 703b2, an intermediate layer 706b, a layer 704b, and the common layer 114.

[0084] The unit 703b is sandwiched between the common electrode 115 and the pixel electrode 111b, and the unit 703b2 is sandwiched between the common electrode 115 and the unit 703b.

[0085] Intermediate layer 706b is sandwiched between unit 703b2 and unit 703b, and intermediate layer 706b has layers 706b1 and 706b2. Layer 706b2 is sandwiched between layer 706b1 and unit 703b.

[0086] The layer 706b2 includes a first inorganic compound and a first organic compound.

[0087] The unit 703a, the unit 703a2, the unit 703b, and the unit 703b2 each include a light-emitting material.

[0088] <<Configuration Example of Insulating Layer 125>> The insulating layer 125 covers part of the top surface and the side surface of the unit 703a2 and part of the top surface and the side surface of the unit 703b2.

[0089] <<Configuration Example of Insulating Layer 127>> The insulating layer 127 overlaps with part of the upper surface and the side surface of the unit 703a2 and part of the upper surface and the side surface of the unit 703b2 via the insulating layer 125.

[0090] In a cross-sectional view, the end portion of the insulating layer 127 has a tapered shape with a taper angle of less than 90°, and the insulating layer 127 covers at least a part of the side surface of the insulating layer 125. The upper surface of the insulating layer 127 is covered with the common electrode 115. Note that the details of the structures of the insulating layer 125 and the insulating layer 127 will be described in Embodiment 2.

[0091] As a result, a gap is formed between the intermediate layer 706a and the intermediate layer 706b. Furthermore, the insulating layer 125 is formed along the gap. Furthermore, the insulating layer 125 and the insulating layer 127 can suppress the current flowing between the intermediate layer 706a and the intermediate layer 706b. Furthermore, the occurrence of crosstalk between the light-emitting device 130a and the light-emitting device 130b can be suppressed. As a result, a novel display device excellent in convenience, usefulness, and reliability can be provided.

[0092] <Configuration Example 1 of Light-Emitting Device 130X> A configuration of a light-emitting device that can be used in the display device described in this embodiment will be described with reference to FIG.

[0093] The light-emitting device 130X can be used in the display device of one embodiment of the present invention. Note that the description of the structure of the light-emitting device 130X can be applied to the light-emitting device 130a. Specifically, the symbol "X" used in the structure of the light-emitting device 130X can be replaced with "a" and the description of the light-emitting device 130a can be used. Similarly, the structure of the light-emitting device 130X can be applied to the light-emitting device 130b or the light-emitting device 130c. Similarly, the structure of the light-emitting device 130X can be applied to the light-emitting device 130B, the light-emitting device 130G, or the light-emitting device 130R.

[0094] The light-emitting device 130X includes an electrode 111X, an electrode 115X, a unit 703X, a unit 703X2, and an intermediate layer 706X (see FIG. 2).

[0095] The electrode 115X overlaps with the electrode 111X. The unit 703X is sandwiched between the electrode 115X and the electrode 111X, the unit 703X2 is sandwiched between the electrode 115X and the unit 703X, and the intermediate layer 706X has a region sandwiched between the unit 703X2 and the unit 703X.

[0096] The unit 703X has a function of emitting light ELX, and the unit 703X2 has a function of emitting light ELX2.

[0097] In other words, the light-emitting device 130X has multiple stacked units between the electrode 111X and the electrode 115X. The number of stacked units is not limited to two, and three or more units can be stacked. A configuration including multiple stacked units sandwiched between the electrode 111X and the electrode 115X and an intermediate layer 706X sandwiched between the multiple units is sometimes referred to as a stacked light-emitting device or a tandem light-emitting device. This allows for high-luminance light emission while maintaining a low current density. Alternatively, reliability can be improved. Alternatively, driving voltage can be reduced compared with the same luminance. Alternatively, power consumption can be suppressed.

[0098] <<Configuration Example of Unit 703X>> The unit 703X has a single-layer structure or a laminated structure. For example, the unit 703X includes a layer 711X, a layer 712X, and a layer 713X (see FIG. 2). The unit 703X has a function of emitting light ELX.

[0099] Layer 711X comprises a region sandwiched between layers 712X and 713X, layer 712X comprises a region sandwiched between electrode 111X and layer 711X, and layer 713X comprises a region sandwiched between electrode 115X and layer 711X.

[0100] For example, the unit 703X may include a layer selected from functional layers such as a light-emitting layer, a hole-transporting layer, an electron-transporting layer, a carrier-blocking layer, etc. Also, the unit 703X may include a layer selected from functional layers such as a hole-injecting layer, an electron-injecting layer, an exciton-blocking layer, and a charge-generating layer.

[0101] <<Structure Example of Layer 712X>> For example, a material having a hole-transporting property can be used for the layer 712X. The layer 712X can also be referred to as a hole-transporting layer. Note that a structure in which a material having a larger band gap than that of the light-emitting material contained in the layer 711X is used for the layer 712X is preferable. This can suppress energy transfer from excitons generated in the layer 711X to the layer 712X.

[0102] [Material having hole transport properties] A material having a hole mobility of 1×10 −６ cm２ A material having a hole transporting property can be suitably used as a material having a hole transporting property.

[0103] For example, an amine compound or an organic compound having a π-electron-rich heteroaromatic ring skeleton can be used as a material having hole transport properties. Specifically, a compound having an aromatic amine skeleton, a compound having a carbazole skeleton, a compound having a thiophene skeleton, a compound having a furan skeleton, or the like can be used. In particular, a compound having an aromatic amine skeleton or a compound having a carbazole skeleton is preferable because it has good reliability, high hole transport properties, and contributes to reducing driving voltage.

[0104] Examples of compounds having an aromatic amine skeleton include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), and 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP). , 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBiBP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), and the like can be used.

[0105] Examples of compounds having a carbazole skeleton that can be used include 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4′-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), and 3,3′-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP).

[0106] Examples of compounds having a thiophene skeleton that can be used include 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV).

[0107] Examples of compounds having a furan skeleton that can be used include 4,4′,4″-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), and the like.

[0108] <<Structural Example of Layer 713X>> For example, a material having an electron-transporting property, a material having an anthracene skeleton, a mixed material, or the like can be used for the layer 713X. The layer 713X can also be referred to as an electron-transporting layer. Note that a structure in which a material having a larger band gap than that of the light-emitting material contained in the layer 711X is used for the layer 713X is preferable. This can suppress energy transfer from excitons generated in the layer 711X to the layer 713X.

[0109] [Electron-Transporting Material] For example, a metal complex or an organic compound having a π-electron-deficient heteroaromatic ring skeleton can be used as the electron-transporting material.

[0110] When the square root of the electric field strength [V / cm] is 600, the electron mobility is 1×10 −７ cm ２ / Vs or more, 5×10 −５ cm ２ A material having a .DELTA. / Vs or less can be suitably used as a material having electron transport properties. This can suppress the electron transport properties in the electron transport layer. Alternatively, it can control the amount of electrons injected into the light-emitting layer. Alternatively, it can prevent the light-emitting layer from becoming an electron-excess state.

[0111] Examples of metal complexes include bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq ２ ), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ), and the like can be used.

[0112] Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include heterocyclic compounds having a polyazole skeleton, heterocyclic compounds having a diazine skeleton, heterocyclic compounds having a pyridine skeleton, and heterocyclic compounds having a triazine skeleton. In particular, heterocyclic compounds having a diazine skeleton or heterocyclic compounds having a pyridine skeleton are preferred because of their high reliability. Furthermore, heterocyclic compounds having a diazine (pyrimidine or pyrazine) skeleton have high electron transport properties and can reduce driving voltage.

[0113] Examples of heterocyclic compounds having a polyazole skeleton include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: O XD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2′,2″-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), and the like can be used.

[0114] Examples of heterocyclic compounds having a diazine skeleton include 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3′-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3′-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), and 2-[3′-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II). ]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothienyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzo[h]quinazoline (abbreviation: 4,8mDBtP2Bqn), etc. can be used.

[0115] Examples of heterocyclic compounds having a pyridine skeleton include 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), and the like.

[0116] Examples of heterocyclic compounds having a triazine skeleton include 2-[3′-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 2-[(1,1′-biphenyl)-4-yl]-4-phenyl-6-[9,9′-spirobi(9H-fluoren)-2-yl]-1,3,5-triazine (abbreviation: BP-SFT zn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), and the like can be used.

[0117] [Material Having an Anthracene Skeleton] An organic compound having an anthracene skeleton can be used for the layer 713X. In particular, an organic compound including both an anthracene skeleton and a heterocyclic skeleton can be suitably used.

[0118] For example, an organic compound containing both an anthracene skeleton and a nitrogen-containing five-membered ring skeleton can be used. Alternatively, an organic compound containing both an anthracene skeleton and a nitrogen-containing five-membered ring skeleton containing two heteroatoms in the ring can be used. Specifically, a pyrazole ring, an imidazole ring, an oxazole ring, a thiazole ring, or the like can be suitably used as the heterocyclic skeleton.

[0119] For example, an organic compound containing both an anthracene skeleton and a nitrogen-containing six-membered ring skeleton can be used. Alternatively, an organic compound containing both an anthracene skeleton and a nitrogen-containing six-membered ring skeleton containing two heteroatoms in the ring can be used. Specifically, a pyrazine ring, a pyrimidine ring, a pyridazine ring, or the like can be suitably used as the heterocyclic skeleton.

[0120] [Configuration Example of Mixed Material] A material in which a plurality of substances are mixed can be used for the layer 713X. Specifically, a mixed material containing an alkali metal, an alkali metal compound, or an alkali metal complex, and a substance having an electron-transporting property can be used for the layer 713X. Note that in this specification and the like, the above-described light-emitting device may be referred to as a Recombination-Site Tailoring Injection structure (ReSTI structure).

[0121] Note that the HOMO level of the material having an electron transporting property is more preferably equal to or higher than −6.0 eV. In addition, it is preferable that the alkali metal, alkali metal compound, or alkali metal complex exists with a concentration difference in the thickness direction of the layer 713X.

[0122] For example, a metal complex containing an 8-hydroxyquinolinato structure can be used. Also, a methyl-substituted metal complex containing an 8-hydroxyquinolinato structure (for example, a 2-methyl-substituted or 5-methyl-substituted metal complex) can be used.

[0123] Examples of metal complexes containing an 8-hydroxyquinolinato structure include 8-hydroxyquinolinato-lithium (abbreviation: Liq), 8-hydroxyquinolinato-sodium (abbreviation: Naq), etc. In particular, complexes of monovalent metal ions, especially lithium complexes, are preferred, with Liq being more preferred.

[0124] <<Structural Example 1 of Layer 711X>> For example, a light-emitting material, or a light-emitting material and a host material, can be used for the layer 711X. The layer 711X can also be referred to as a light-emitting layer. Note that a structure in which the layer 711X is disposed in a region where holes and electrons recombine is preferable. This allows energy generated by carrier recombination to be efficiently converted into light and emitted.

[0125] Furthermore, it is preferable to arrange the layer 711X away from metals used for the electrodes, etc. This makes it possible to suppress the quenching phenomenon caused by the metals used for the electrodes, etc.

[0126] Furthermore, it is preferable to adjust the distance from the reflective electrode or the like to the layer 711X and place the layer 711X at an appropriate position according to the emission wavelength. This allows the interference phenomenon between the light reflected by the electrode or the like and the light emitted by the layer 711X to be utilized to reinforce the amplitudes. Furthermore, it is possible to strengthen the light spectrum by intensifying the light of a specific wavelength. Furthermore, it is possible to obtain a vivid emission color with high intensity. In other words, it is possible to form a microresonator structure (microcavity) by placing the layer 711X at an appropriate position between the electrodes or the like.

[0127] For example, the luminescent material can be a fluorescent material, a phosphorescent material, or a material exhibiting thermally activated delayed fluorescence (TADF) (also called a TADF material), which allows the energy generated by carrier recombination to be emitted from the luminescent material as light ELX (see FIG. 2).

[0128] [Fluorescent Light-Emitting Substance] A fluorescent light-emitting substance can be used for the layer 711X. For example, the fluorescent light-emitting substances exemplified below can be used for the layer 711X. Note that the fluorescent light-emitting substances are not limited to these, and various known fluorescent light-emitting substances can be used for the layer 711X.

[0129] Specifically, 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2′-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4′-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2′-bipyridine (abbreviation: PAPP2BPy), N,N′-diphenyl-N,N′-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N′-bis(3-methylphenyl)-N,N′-bis[3-(9-phenyl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: YGAPA), : 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra(tert-butyl)perylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N',N '-triphenyl-1,4-phenylenediamine] (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,10-bis[N-(9-phenyl-9H-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), etc. can be used.

[0130] In particular, condensed aromatic diamine compounds typified by pyrenediamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 are preferred because they have high hole trapping properties and are excellent in luminous efficiency or reliability.

[0131] In addition, N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), Coumarin 30, 9,10-diphenyl 2-[N-phenyl-N-(9-phenyl-carbazol-3-yl)-amino]-anthracene (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N',N'-trimethyl- Triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1′-biphenyl-2-yl)-2-anthryl]-N,N′,N′-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1′-biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), coumarin 545T, N,N′-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(1,1′-biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), and the like can be used.

[0132] Further, 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM3), (4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]ki] 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(di 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJ™), and the like can be used.

[0133] [Phosphorescent Material] A phosphorescent material can be used for the layer 711X. For example, the phosphorescent materials exemplified below can be used for the layer 711X. Note that the present invention is not limited thereto, and various known phosphorescent materials can be used for the layer 711X.

[0134] For example, organometallic iridium complexes having a 4H-triazole skeleton, organometallic iridium complexes having a 1H-triazole skeleton, organometallic iridium complexes having an imidazole skeleton, organometallic iridium complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand, organometallic iridium complexes having a pyrimidine skeleton, organometallic iridium complexes having a pyrazine skeleton, organometallic iridium complexes having a pyridine skeleton, rare earth metal complexes, platinum complexes, and the like can be used for the layer 711X.

[0135] [Phosphorescent Material (Blue)] Examples of organometallic iridium complexes having a 4H-triazole skeleton include tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp) ３ ]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz) ３ ]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPrptz-3b) ３ ]), etc. can be used.

[0136] Examples of organometallic iridium complexes having a 1H-triazole skeleton include tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp) ３ ]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me) ３ ]), etc. can be used.

[0137] Examples of organometallic iridium complexes having an imidazole skeleton include fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpmi) ３]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me) ３ ]), etc. can be used.

[0138] Examples of organometallic iridium complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand include bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ]iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ]iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C ２’} Iridium(III) picolinate (abbreviation: [Ir(CF ３ ppy) ２ (pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ ] Iridium (III) acetylacetonate (abbreviation: FIracac), etc. can be used.

[0139] These compounds exhibit blue phosphorescence and have a peak emission wavelength in the range of 440 nm to 520 nm.

[0140] [Phosphorescent Material (Green)] Examples of organometallic iridium complexes having a pyrimidine skeleton include tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ３ ]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ３ ]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ２ (acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ２(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm) ２ (acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm) ２ (acac)]), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm) ２ (acac)]), etc. can be used.

[0141] Examples of organometallic iridium complexes having a pyrazine skeleton include (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me) ２ (acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr) ２ (acac)]), etc. can be used.

[0142] Examples of organometallic iridium complexes having a pyridine skeleton include tris(2-phenylpyridinato-N,C ２’ ) Iridium(III) (abbreviation: [Ir(ppy) ３ ]), bis(2-phenylpyridinato-N,C ２’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy) ２ (acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq) ２ (acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq) ３ ]), tris(2-phenylquinolinato-N,C ２’ ) Iridium(III) (abbreviation: [Ir(pq) ３ ]), bis(2-phenylquinolinato-N,C ２’ ) iridium(III) acetylacetonate (abbreviation: [Ir(pq) ２(acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3) ２ (mbfpypy-d3)]), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) ２ (mbfpypy-d3)]), etc. can be used.

[0143] The rare earth metal complexes include tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac) ３ (Phen)]), etc.

[0144] These compounds mainly exhibit green phosphorescence, with a peak emission wavelength between 500 nm and 600 nm. Organometallic iridium complexes having a pyrimidine skeleton are also remarkably superior in reliability and luminous efficiency.

[0145] [Phosphorescent material (red)] Examples of organometallic iridium complexes having a pyrimidine skeleton include (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm) ２ (dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm) ２ (dpm)]), bis[4,6-di(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(dpm) ２ (dpm)]), etc. can be used.

[0146] Examples of organometallic iridium complexes having a pyrazine skeleton include (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr) ２(acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr) ２ (dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq) ２ (acac)]), etc. can be used.

[0147] Examples of organometallic iridium complexes having a pyridine skeleton include tris(1-phenylisoquinolinato-N,C ２’ ) Iridium(III) (abbreviation: [Ir(piq) ３ ]), bis(1-phenylisoquinolinato-N,C ２’ ) iridium(III) acetylacetonate (abbreviation: [Ir(piq) ２ (acac)]), etc. can be used.

[0148] Examples of rare earth metal complexes include tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM) ３ (Phen)]), tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA) ３ (Phen)]), etc. can be used.

[0149] As the platinum complex, 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP) and the like can be used.

[0150] These compounds exhibit red phosphorescence, with an emission peak at 600 nm to 700 nm. The organometallic iridium complexes having a pyrazine skeleton emit red light with a chromaticity suitable for use in display devices.

[0151] [Substance Exhibiting Thermally Activated Delayed Fluorescence (TADF)] A TADF material can be used for the layer 711X. For example, the TADF materials exemplified below can be used as the luminescent material. However, without being limited thereto, various known TADF materials can be used as the luminescent material.

[0152] TADF materials have a small difference between the S1 and T1 levels, allowing reverse intersystem crossing (upconversion) from a triplet excited state to a singlet excited state with a small amount of thermal energy. This allows efficient generation of a singlet excited state from a triplet excited state. Furthermore, the triplet excited energy can be converted into luminescence.

[0153] Furthermore, an exciplex (also called an exciplex) that forms an excited state with two types of substances has an extremely small difference between the S1 level and the T1 level, and functions as a TADF material that can convert triplet excitation energy into singlet excitation energy.

[0154] The T1 level can be determined by using a phosphorescence spectrum observed at low temperatures (e.g., 77 K to 10 K). When a tangent line is drawn at the base of the fluorescence spectrum on the short wavelength side of the TADF material, and the energy of the wavelength of the extrapolated line is defined as the S1 level, and when a tangent line is drawn at the base of the phosphorescence spectrum on the short wavelength side of the TADF material, and the energy of the wavelength of the extrapolated line is defined as the T1 level, the difference between S1 and T1 is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0155] When a TADF material is used as a light-emitting material, the S1 level of the host material is preferably higher than the S1 level of the TADF material, and the T1 level of the host material is preferably higher than the T1 level of the TADF material.

[0156] For example, TADF materials can include fullerene and its derivatives, acridine and its derivatives, eosin derivatives, etc. Also, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), etc. can be used as TADF materials.

[0157] Specifically, protoporphyrin-tin fluoride complex (SnF), whose structural formula is shown below, ２ (Proto IX)), mesoporphyrin-tin fluoride complex (SnF ２ (Meso IX)), hematoporphyrin-tin fluoride complex (SnF ２ (Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF ２ (Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF ２ (OEP)), etioporphyrin-tin fluoride complex (SnF ２ (Etio I)), octaethylporphyrin-platinum chloride complex (PtCl ２ OEP), etc. can be used.

[0158]

[0159] Furthermore, for example, a heterocyclic compound having one or both of a π-electron rich heteroaromatic ring and a π-electron deficient heteroaromatic ring can be used as the TADF material.

[0160] Specifically, the structural formulas of these compounds are as follows: 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9′-phenyl-9H,9′H-3,3′-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4 ,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10′H-spiro[acridin-9,9′-anthracene]-10′-one (abbreviation: ACRSA), and the like can be used.

[0161]

[0162] The heterocyclic compound has a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring, and therefore has high electron transport and hole transport properties, and is therefore preferred. In particular, among skeletons having a π-electron-deficient heteroaromatic ring, pyridine skeletons, diazine skeletons (pyrimidine skeletons, pyrazine skeletons, pyridazine skeletons), and triazine skeletons are preferred because they are stable and reliable. In particular, benzofuropyrimidine skeletons, benzothienopyrimidine skeletons, benzofuropyrazine skeletons, and benzothienopyrazine skeletons are preferred because they have high acceptor properties and good reliability.

[0163] Among skeletons having a π-electron-rich heteroaromatic ring, it is preferable to have at least one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton because they are stable and reliable. Note that the dibenzofuran skeleton is preferable as the furan skeleton, and the dibenzothiophene skeleton is preferable as the thiophene skeleton. Furthermore, the indole skeleton, the carbazole skeleton, the indolocarbazole skeleton, the bicarbazole skeleton, and the 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferable as the pyrrole skeleton.

[0164] In addition, a substance in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded is particularly preferred because the electron-donating property of the π-electron-rich heteroaromatic ring and the electron-accepting property of the π-electron-deficient heteroaromatic ring are both strong, and the energy difference between the S1 level and the T1 level is small, thereby enabling efficient thermally activated delayed fluorescence to be obtained. In addition, an aromatic ring bonded to an electron-withdrawing group such as a cyano group may be used instead of the π-electron-deficient heteroaromatic ring. In addition, an aromatic amine skeleton, a phenazine skeleton, or the like may be used as the π-electron-rich skeleton.

[0165] Furthermore, examples of the π-electron-deficient skeleton that can be used include a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane or boranthrene, an aromatic ring or heteroaromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, and a sulfone skeleton.

[0166] In this way, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used in place of at least one of a π-electron-deficient heteroaromatic ring and a π-electron-rich heteroaromatic ring.

[0167] <<Structural Example 2 of Layer 711X>> A material having carrier transport properties can be used as the host material. For example, a material having hole transport properties, a material having electron transport properties, a substance exhibiting thermally activated delayed fluorescence (TADF), a material having an anthracene skeleton, a mixed material, or the like can be used as the host material. Note that a structure using a material having a larger band gap than the light-emitting material contained in the layer 711X as the host material is preferable. This can suppress energy transfer from excitons generated in the layer 711X to the host material.

[0168] [Material having hole transport properties] A material having a hole mobility of 1×10 −６ cm ２ A material having a hole transporting property can be suitably used as a material having a hole transporting property.

[0169] For example, a material having a hole-transport property that can be used for the layer 712X can be used for the layer 711X. Specifically, a material having a hole-transport property that can be used for a hole-transport layer can be used for the layer 711X.

[0170] [Electron-Transporting Material] For example, a metal complex or an organic compound having a π-electron-deficient heteroaromatic ring skeleton can be used as the electron-transporting material.

[0171] For example, a material having an electron-transporting property that can be used for the layer 713X can be used for the layer 711X. Specifically, a material having an electron-transporting property that can be used for an electron-transport layer can be used for the layer 711X.

[0172] [Materials Having an Anthracene Skeleton] Organic compounds having an anthracene skeleton can be used as host materials. In particular, when a fluorescent material is used as the light-emitting material, organic compounds having an anthracene skeleton are suitable. This allows for the realization of light-emitting devices with good luminous efficiency and durability.

[0173] As the organic compound having an anthracene skeleton, an organic compound having a diphenylanthracene skeleton, particularly a 9,10-diphenylanthracene skeleton, is preferred because it is chemically stable. Furthermore, when the host material has a carbazole skeleton, it is preferred because it has improved hole injection and transport properties. In particular, when the host material contains a dibenzocarbazole skeleton, it is preferred because its HOMO level is shallower by about 0.1 eV than that of carbazole, making it easier for holes to enter, and it also has excellent hole transport properties and high heat resistance. From the viewpoint of hole injection and transport properties, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton.

[0174] Therefore, a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton, a substance having both a 9,10-diphenylanthracene skeleton and a benzocarbazole skeleton, or a substance having both a 9,10-diphenylanthracene skeleton and a dibenzocarbazole skeleton is preferable as the host material.

[0175] For example, 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-{4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4′-yl}anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-phenyl-3-[4-(10-phenyl [4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), and the like can be used.

[0176] In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties.

[0177] [Substances Exhibiting Thermally Activated Delayed Fluorescence (TADF)] A TADF material can be used as a host material. The TADF material can convert triplet excitation energy into singlet excitation energy through reverse intersystem crossing. Furthermore, a TADF material preferably has a structure in which carriers recombine. This allows triplet excitation energy generated by carrier recombination to be efficiently converted into singlet excitation energy through reverse intersystem crossing. Furthermore, the excitation energy can be transferred to a light-emitting material. In other words, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor. This can improve the luminous efficiency of a light-emitting device.

[0178] A fluorescent material can be suitably used as the energy acceptor. In particular, when the S1 level of the TADF material is higher than the S1 level of the fluorescent material, high luminous efficiency can be obtained. Furthermore, it is more preferable that the T1 level of the TADF material is higher than the S1 level of the fluorescent material. Furthermore, it is more preferable that the T1 level of the TADF material is higher than the T1 level of the fluorescent material.

[0179] It is also preferable to use a TADF material that emits light that overlaps with the wavelength of the lowest energy absorption band of the fluorescent material, which facilitates the transfer of excitation energy from the TADF material to the fluorescent material and allows for efficient emission.

[0180] Furthermore, the fluorescent substance used as the energy acceptor preferably has a luminophore (a skeleton that causes light emission) and a protecting group around the luminophore. It is even more preferable to have multiple protecting groups. This can suppress the phenomenon in which triplet excitation energy generated in the TADF material is transferred to the triplet excitation energy of the fluorescent substance.

[0181] Here, the term "luminophore" refers to an atomic group (skeleton) that causes light emission in a fluorescent substance. The luminophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a fused aromatic ring or a fused heteroaromatic ring.

[0182] Examples of the fused aromatic ring or fused heteroaromatic ring include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, a phenothiazine skeleton, etc. In particular, fluorescent substances having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton are preferred because of their high fluorescence quantum yield.

[0183] Furthermore, the protecting group surrounding the luminophore is preferably a substituent that does not have a π bond. For example, saturated hydrocarbons are preferred. Specifically, methyl groups, branched alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms in a ring, and trialkylsilyl groups having 3 to 10 carbon atoms can be used as protecting groups. Substituents that do not have a π bond have poor carrier transport function. This allows the luminophore of the fluorescent material to be separated from the TADF material without significantly affecting carrier transport or carrier recombination, thereby optimizing the distance between the TADF material and the luminophore of the fluorescent material. Furthermore, energy transfer via the Dexter mechanism can be suppressed, while energy transfer via the Förster mechanism can be promoted.

[0184] For example, a TADF material that can be used as a light-emitting material can be used as a host material.

[0185] [Configuration Example 1 of Mixed Material] A material obtained by mixing a plurality of substances can be used as the host material. For example, a material having electron transport properties and a material having hole transport properties can be used as the mixed material. The weight ratio of the material having hole transport properties to the material having electron transport properties contained in the mixed material may be set to (material having hole transport properties / material having electron transport properties) = (1 / 19) or more and (19 / 1) or less. This allows the carrier transport properties of the layer 711X to be easily adjusted. Furthermore, the recombination region can be easily controlled.

[0186] [Configuration Example 2 of Mixed Material] A material mixed with a phosphorescent material can be used as a host material. When a fluorescent material is used as an emitting material, the phosphorescent material can be used as an energy donor that provides excitation energy to the fluorescent material.

[0187] When a material containing a phosphorescent substance is used as a host material, the phosphorescent substance preferably has a protecting group, and more preferably has a plurality of protecting groups.

[0188] Furthermore, a substituent without a π bond is preferred as a protecting group. For example, saturated hydrocarbons are preferred. Specifically, a branched alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms in a ring, or a trialkylsilyl group having 3 to 10 carbon atoms can be used as a protecting group. Substituents without a π bond have poor carrier transport function. This allows the luminophores of the fluorescent material to be separated from the phosphorescent material, thereby achieving an appropriate distance between the phosphorescent material and the luminophores of the fluorescent material, without substantially affecting carrier transport or carrier recombination. Furthermore, energy transfer via the Dexter mechanism can be suppressed and energy transfer via the Förster mechanism can be promoted.

[0189] For the same reason, when a material containing a phosphorescent material is used as a host material, the fluorescent material preferably has a luminophore (a skeleton that causes luminescence) and protecting groups around the luminophore. It is even more preferable that the fluorescent material has multiple protecting groups.

[0190] [Structure Example 3 of Mixed Material] A mixed material containing a material that forms an exciplex can be used as a host material. For example, a material whose emission spectrum of the formed exciplex overlaps with the wavelength of the lowest-energy absorption band of the light-emitting material can be used as a host material. This allows smooth energy transfer, improving light-emitting efficiency. Alternatively, driving voltage can be suppressed. With this structure, light emission can be efficiently obtained using Exciplex-Triple Energy Transfer (ExTET), which is energy transfer from an exciplex to a light-emitting material (phosphorescent material).

[0191] At least one of the materials forming the exciplex can be a phosphorescent material, which allows for the utilization of reverse intersystem crossing or the efficient conversion of triplet excitation energy to singlet excitation energy.

[0192] As a combination of materials for forming an exciplex, it is preferable that the HOMO level of the material having hole transport properties is equal to or higher than the HOMO level of the material having electron transport properties. Alternatively, it is preferable that the LUMO level of the material having hole transport properties is equal to or higher than the LUMO level of the material having electron transport properties. This allows for efficient formation of an exciplex. The LUMO level and HOMO level of the material can be derived from electrochemical properties (reduction potential and oxidation potential). Specifically, the reduction potential and oxidation potential can be measured using cyclic voltammetry (CV) measurement.

[0193] The formation of exciplexes can be confirmed, for example, by comparing the emission spectra of a material having hole transport properties, a material having electron transport properties, and a mixed film obtained by mixing these materials, and observing the phenomenon in which the emission spectrum of the mixed film is shifted to longer wavelengths than the emission spectra of each material (or has a new peak on the longer wavelength side). Alternatively, the formation of exciplexes can be confirmed by comparing the transient photoluminescence (PL) of a material having hole transport properties, the transient PL of a material having electron transport properties, and a mixed film obtained by mixing these materials, and observing differences in transient response, such as the transient PL lifetime of the mixed film having a longer-lifetime component or a larger proportion of delayed components than the transient PL lifetimes of the individual materials. The above-mentioned transient PL may also be interpreted as transient electroluminescence (EL). In other words, the formation of exciplexes can also be confirmed by comparing the transient EL of a material having hole transport properties, the transient EL of a material having electron transport properties, and a mixed film obtained by mixing these materials, and observing the differences in transient response.

[0194] <<Configuration Example of Intermediate Layer 706X>> The intermediate layer 706X has a function of supplying electrons to one of the unit 703X and the unit 703X2, and supplying holes to the other.

[0195] A single layer or a stack of multiple layers can be used for the intermediate layer 706X. For example, the intermediate layer 706X includes a layer 706X1, a layer 706X2, and a layer 706X3. The layer 706X2 is sandwiched between the layer 706X1 and the unit 703X, and the layer 706X3 is sandwiched between the layer 706X1 and the layer 706X2.

[0196] <<Configuration Example of Layer 706X1>> For example, the layer 706X1 may be made of a material that supplies electrons to the anode side and holes to the cathode side when a voltage is applied. Specifically, the layer 706X1 may supply electrons to the unit 703X disposed on the anode side and holes to the unit 703X2 disposed on the cathode side. The layer 706X1 may also be referred to as a charge generation layer.

[0197] A substance having an acceptor property can be used for the layer 706X1. Alternatively, a composite material containing a plurality of substances can be used for the layer 706X1. Note that the layer 706X1 containing the composite material preferably has a conductivity of 1×10 ２ [Ω・cm] or more 1×10 ８ It has an electrical resistivity of [Ω·cm] or less.

[0198] [Substance Having Acceptor Property] Organic compounds and inorganic compounds can be used as the substance having acceptor property. The substance having acceptor property can extract electrons from the adjacent hole transport layer or the material having hole transport property by applying an electric field.

[0199] For example, a compound having an electron-withdrawing group (a halogen group or a cyano group) can be used as a substance having acceptor properties. Note that organic compounds having acceptor properties are easy to vapor-deposit and form into films. This can improve the productivity of light-emitting devices.

[0200] Specifically, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F ４ -TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyren-2-ylidene)malononitrile, and the like can be used.

[0201] In particular, a compound in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms, such as HAT-CN, is thermally stable and is therefore preferred.

[0202] [3] Radialene derivatives having an electron-withdrawing group (particularly a halogen group such as a fluoro group or a cyano group) are also preferred because they have very high electron-accepting properties.

[0203] Specifically, α,α',α''-1,2,3-cyclopropane triylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α''-1,2,3-cyclopropane triylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α''-1,2,3-cyclopropane triylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], and the like can be used.

[0204] Furthermore, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, or the like can be used as the substance having acceptor properties.

[0205] In addition, phthalocyanine (abbreviation: H ２ and compounds having an aromatic amine skeleton such as 4,4′-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB) and N,N′-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N′-diphenyl-(1,1′-biphenyl)-4,4′-diamine (abbreviation: DNTPD).

[0206] Alternatively, polymers such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (PEDOT / PSS) can be used.

[0207] [Structure Example 1 of Composite Material] For example, a composite material containing a substance having an acceptor property and a material having a hole-transport property can be used for the layer 706X1.

[0208] For example, compounds having an aromatic amine skeleton, carbazole derivatives, aromatic hydrocarbons, aromatic hydrocarbons having a vinyl group, and polymeric compounds (oligomers, dendrimers, polymers, etc.) can be used as the material having hole transport properties for the composite material. −６ cm ２ A material having a hole transporting property can be suitably used as the material of the composite material.

[0209] Furthermore, a substance having a relatively deep HOMO level can be preferably used as the material having hole-transporting properties of the composite material. Specifically, the HOMO level is preferably −5.7 eV or more and −5.3 eV or less. This can facilitate injection of holes into the unit 703X2. Alternatively, it can facilitate injection of holes into the layer 712X2. Alternatively, it can improve the reliability of the light-emitting device.

[0210] Examples of compounds having an aromatic amine skeleton that can be used include N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B).

[0211] Examples of the carbazole derivative include 3-[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazol-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcarbazol-3-yl)amino]-9-phenylcarbazole, and carbazole (abbreviation: PCzPCN1), 4,4′-di(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, and the like can be used.

[0212] Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAnth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert-butyl-9,10 10,10'-bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'-bianthryl, 10,10'-bis(2-phenylphenyl)-9,9'-bianthryl, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthryl, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, pentacene, coronene, and the like can be used.

[0213] Examples of aromatic hydrocarbons having a vinyl group include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA), and the like.

[0214] Examples of polymer compounds that can be used include poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD).

[0215] For example, a substance having a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton can be suitably used as a material having hole transport properties for the composite material. Furthermore, a substance having an aromatic amine with a substituent containing a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine with a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group can be used as a material having hole transport properties for the composite material. The use of a substance having an N,N-bis(4-biphenyl)amino group can improve the reliability of the light-emitting device.

[0216] Examples of these materials include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4′-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4″-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2 -d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl -4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-0 3), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-Diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4'' -phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4′-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4′-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4′-diphenyl-4″-[4′-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4′-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(1,1′ -biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(4-biphenylyl)- 9,9'-Spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(1,1'-biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(1,1'-biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(4-biphenyl)-N-(dibenzofuran-4-yl)-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenyl 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-bifluoren-2-amine (abbreviation: PCBASF), N-(1,1'-biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), N,N-bis(9,9- N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, etc. can be used.

[0217] <<Structure Example of Layer 706X2>> For example, a material having an electron injecting property can be used for the layer 706X2. The layer 706X2 can also be referred to as an electron injecting layer.

[0218] The layer 706X2 also contains unpaired electrons, and the unpaired electrons are measured by an electron spin resonance (ESR) apparatus to determine whether the unpaired electrons are 1×10 １６ spins / cm ３ 1x10 or more １８ spins / cm ３ The unpaired electron can be observed at the following spin density: The unpaired electron has a g value in the range of 2.003 to 2.004.

[0219] Furthermore, the unpaired electrons can be observed in air with a spin density of 50% or more of the initial value after 24 hours using an electron spin resonance (ESR) spectrometer. Note that the elapsed time can be, for example, the time after the sealing structure of the manufactured light-emitting device is destroyed.

[0220] This also reduces the barrier between the intermediate layer 706X and the unit 703X when electrons are injected from the intermediate layer 706X to the unit 703X. Furthermore, the flexibility of processing steps applicable after the formation of the layer 706X2 can be increased. Furthermore, for example, resistance to a heat treatment process can be increased. Furthermore, for example, resistance to a chemical treatment process can be increased. Furthermore, for example, after the layer 706X1 is formed on the layer 706X2, the layer 706X1 and the layer 706X2 can be processed into a predetermined shape using a photolithography method. Furthermore, for example, after the unit 703X2 is formed, the unit 703X2, the intermediate layer 706X, and the unit 703X can be processed into a predetermined shape using a photolithography method. As a result, a novel display device with excellent convenience, usefulness, and reliability can be provided.

[0221] For example, a mixed material containing an organic compound having an electron-transporting property and an inorganic compound having an electron-donating property can be used for the layer 706X2.

[0222] [Structure Example 1 of Organic Compound Having Electron Transport Property] An organic compound having an unshared electron pair can be used as an organic compound having electron transport property. The organic compound interacts with an inorganic compound having electron donating property to form a half-occupied orbital.

[0223] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as the organic compound having an unshared electron pair. Note that NBPhen has a higher glass transition temperature (Tg) and is superior in heat resistance compared to BPhen.

[0224] [Structural Example 2 of Organic Compound Having Electron-Transporting Property] An organic compound having an electron-deficient heteroaromatic ring can be used for the layer 706X2. Specifically, a compound having at least one of a pyridine ring, a diazine ring (a pyrimidine ring, a pyrazine ring, or a pyridazine ring), and a triazine ring can be used.

[0225] An organic compound having a lowest unoccupied molecular orbital (LUMO) level in the range of −3.6 eV to −2.3 eV can be used for the layer 706X2. Note that the HOMO level and LUMO level of an organic compound can generally be estimated by cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, or the like.

[0226] [Configuration Example 1 of Inorganic Compound] An inorganic compound containing a metal element and oxygen can be used as the electron-donating inorganic compound. For example, an inorganic compound containing an alkali metal (Li, Na, K, Rb, Cs, and Fr) and oxygen can be used. Alternatively, an inorganic compound containing an alkaline earth metal and oxygen can be used. In particular, an inorganic compound containing Li and oxygen is preferably used. Note that an organic metal complex can also be used for the layer 706X2. For example, an organic metal complex containing an alkali metal can also be used. Specifically, 8-hydroxyquinolinato-lithium (abbreviation: Liq), 8-hydroxyquinolinato-sodium (abbreviation: Naq), 8-hydroxyquinolinato-potassium (abbreviation: Kq), etc. can be used. Note that when using such a metal complex, it is preferable to use it in combination with, for example, the alkali metal, the alkaline earth metal, or Al.

[0227] This makes it possible to reduce the driving voltage of the light-emitting device and the power consumption of the display device, thereby providing a novel display device that is highly convenient, useful, and reliable.

[0228] <<Configuration Example of Layer 706X3>> For example, a material having electron transport properties can be used for the layer 706X3. The layer 706X3 can also be referred to as an electron relay layer. By using the layer 706X3, the layer in contact with the anode side of the layer 706X3 can be separated from the layer in contact with the cathode side of the layer 706X3. The interaction between the layer in contact with the anode side of the layer 706X3 and the layer in contact with the cathode side of the layer 706X3 can be reduced. Furthermore, electrons can be smoothly supplied to the layer in contact with the anode side of the layer 706X3.

[0229] A substance having a LUMO level between the LUMO level of a substance having acceptor properties included in a layer in contact with the cathode side of the layer 706X3 and the LUMO level of a substance included in a layer in contact with the anode side of the layer 706X3 can be suitably used for the layer 706X3.

[0230] For example, a material having a LUMO level in the range of −5.0 eV or more, preferably −5.0 eV or more and −3.0 eV or less, more preferably −4.0 eV or more and −3.3 eV or less can be used for the layer 706X3.

[0231] Alternatively, a material having an unpaired electron can be used for the layer 706X3. Specifically, a phthalocyanine-based material can be used for the layer 706X3. Alternatively, a metal complex having a metal-oxygen bond and an aromatic ligand can be used for the layer 706X3.

[0232] <<Configuration Example 1 of Unit 703X2>> The unit 703X2 has a single-layer structure or a laminated structure. For example, the unit 703X2 includes a layer 711X2, a layer 712X2, and a layer 713X2 (see FIG. 2). The unit 703X2 has a function of emitting light ELX2.

[0233] Layer 711X2 comprises the area sandwiched between layers 712X2 and 713X2, layer 712X2 comprises the area sandwiched between intermediate layer 706X and layer 711X2, and layer 713X2 comprises the area sandwiched between electrode 115X and layer 711X2.

[0234] For example, the unit 703X2 may include a layer selected from functional layers such as a light-emitting layer, a hole-transporting layer, an electron-transporting layer, a carrier-blocking layer, etc. Also, the unit 703X2 may include a layer selected from functional layers such as a hole-injecting layer, an electron-injecting layer, an exciton-blocking layer, and a charge-generating layer.

[0235] The configuration that can be used for the unit 703X can also be used for the unit 703X2.

[0236] For example, the same configuration as that employed in unit 703X can be used for unit 703X2. Furthermore, a configuration in which the thickness of a portion of unit 703X is changed can be used for unit 703X2. This allows the distance from a reflective electrode or the like to layer 711X2 to be adjusted. Furthermore, by utilizing the interference phenomenon between light reflected by an electrode or the like and light emitted by layer 711X2, the amplitudes can be reinforced. Furthermore, a microresonator structure (microcavity) can be configured.

[0237] <<Configuration Example 2 of Unit 703X2>> For example, a configuration that is different from the configuration employed in the unit 703X but that emits light of the same hue as the light ELX emitted by the unit 703X can be used for the unit 703X2.

[0238] Specifically, a different structure from that employed for the layer 711X2 can be used for the layer 711X. For example, a fluorescent material can be used for one layer and a phosphorescent material can be used for the other layer.

[0239] In particular, a different configuration may be used for layer 712X2 than that employed for layer 712X.

[0240] In particular, a different configuration may be used for layer 713X2 than that employed for layer 713X.

[0241] <<Configuration Example 3 of Unit 703X2>> For example, the unit 703X2 can be configured to emit light of a different hue from the light ELX emitted by the unit 703X.

[0242] Specifically, a unit 703X that emits yellow light and a unit 703X2 that emits blue light can be used. Alternatively, a unit 703X that emits red light and green light and a unit 703X2 that emits blue light can be used. This makes it possible to provide a light-emitting device that emits light of a desired color. For example, it is possible to provide a light-emitting device that emits white light.

[0243] <Configuration Example 2 of Light-Emitting Device 130X> The light-emitting device 130X includes an electrode 111X, an electrode 115X, a unit 703X, and a layer 704X.

[0244] Layer 704X comprises the area sandwiched between electrode 111X and unit 703X.

[0245] <<Structure Example of Electrode 111X>> For example, a conductive material can be used for the electrode 111X. Specifically, a single layer or a stacked layer of a film containing a metal, an alloy, or a conductive compound can be used for the electrode 111X.

[0246] For example, a film that efficiently reflects light can be used for the electrode 111X. Specifically, a metal film such as an alloy containing silver and copper, an alloy containing silver and palladium, or aluminum can be used for the electrode 111X.

[0247] Furthermore, for example, a metal film that transmits part of the light and reflects the other part of the light can be used for the electrode 111X. This allows a microresonator structure (microcavity) to be provided in the light-emitting device 130X. Alternatively, light of a specific wavelength can be extracted more efficiently than other light. Alternatively, light with a narrow spectral half-width can be extracted. Alternatively, light of a vivid color can be extracted.

[0248] For example, a film that transmits visible light can be used for the electrode 111X. Specifically, a metal film, an alloy film, a conductive oxide film, or the like that is thin enough to transmit light can be used as the electrode 111X in a single layer or stacked layers.

[0249] In particular, a material having a work function of 4.0 eV or more can be suitably used for the electrode 111X.

[0250] For example, a conductive oxide containing indium can be used, such as indium oxide, indium oxide-tin oxide (abbreviation: ITO), indium oxide-tin oxide containing silicon or silicon oxide (abbreviation: ITSO), indium oxide-zinc oxide, or indium oxide containing tungsten oxide and zinc oxide (abbreviation: IWZO).

[0251] Alternatively, for example, a conductive oxide containing zinc can be used, such as zinc oxide, zinc oxide doped with gallium, or zinc oxide doped with aluminum.

[0252] Alternatively, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or a nitride of a metal material (e.g., titanium nitride) can be used. Alternatively, graphene can be used.

[0253] <<Structure Example of Layer 704X>> For example, a material having a hole-injecting property can be used for the layer 704X. The layer 704X can also be referred to as a hole-injecting layer.

[0254] Specifically, a substance having an acceptor property can be used for the layer 704X. Alternatively, a composite material containing a plurality of substances can be used for the layer 704X. This can facilitate injection of holes from the electrode 111X, for example. Alternatively, the driving voltage of the light-emitting device can be reduced.

[0255] [Acceptor Substance] For example, the acceptor substance that can be used for the layer 706X1 can be used for the layer 704X.

[0256] [Structure Example 1 of Composite Material] For example, a composite material containing a substance having an acceptor property and a material having a hole-transport property can be used for the layer 704X. Specifically, the composite material that can be used for the layer 706X1 can be used for the layer 704X. Note that the layer 704X containing the composite material preferably has a density of 1×10 ２ [Ω・cm] or more 1×10 ８ It has an electrical resistivity of [Ω·cm] or less.

[0257] This can facilitate injection of holes into the unit 703X, or into the layer 712X, or can improve the reliability of the light-emitting device.

[0258] Note that when a mixed material containing an alkali metal, an alkali metal compound, or an alkali metal complex, and a substance having electron-transporting properties is used for the layer 713X, the composite material can be suitably used for the layer 704X. In particular, a composite material of a material having hole-transporting properties and a relatively deep HOMO level HM1 of −5.7 eV to −5.4 eV, and a substance having acceptor properties can be used for the layer 704X. This can improve the reliability of the light-emitting device.

[0259] Alternatively, the mixed material may be used for the layer 713X, the composite material may be used for the layer 704X, and a substance having a HOMO level HM2 in the range of −0.2 eV to 0 eV with respect to the relatively deep HOMO level HM1 may be used for the layer 712X. This may further improve the reliability of the light-emitting device.

[0260] [Configuration Example 2 of Composite Material] For example, a composite material containing a substance having acceptor properties, a material having hole-transport properties, and an alkali metal fluoride or an alkaline earth metal fluoride can be used as a material having hole-injection properties. In particular, a composite material containing fluorine atoms at an atomic ratio of 20% or more can be preferably used. This can reduce the refractive index of the layer 704X. Alternatively, a layer with a low refractive index can be formed inside the light-emitting device. Alternatively, the external quantum efficiency of the light-emitting device can be improved.

[0261] <Configuration Example 3 of Light-Emitting Device 130X> The light-emitting device 130X also includes an electrode 111X, an electrode 115X, a unit 703X2, and a layer 114X.

[0262] The electrode 115X has an area overlapping with the electrode 111X, the unit 703X2 has an area sandwiched between the electrode 115X and the electrode 111X, and the layer 114X has an area sandwiched between the electrode 115X and the unit 703X2.

[0263] <Configuration Example of Electrode 115X> For example, a conductive material can be used for the electrode 115X. Specifically, a film containing a metal, an alloy, or a conductive compound can be used for the electrode 115X in a single layer or a multilayer structure. The conductive material can be shared with other light-emitting devices. For example, a part of the common electrode 115 can be used for the electrode 115X.

[0264] For example, the material that can be used for the electrode 111X can be used for the electrode 115X. In particular, a material having a work function smaller than that of the electrode 111X can be suitably used for the electrode 115X. Specifically, a material having a work function of 3.8 eV or less is preferred.

[0265] For example, elements belonging to Group 1 of the periodic table, elements belonging to Group 2 of the periodic table, rare earth metals, and alloys containing these can be used for the electrode 115X.

[0266] Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), strontium (Sr), europium (Eu), ytterbium (Yb), and alloys containing these (MgAg, AlLi) can be used for electrode 115X.

[0267] <<Configuration Example of Layer 114X>> For example, a material having electron injection properties can be used for the layer 114X. The layer 114X can also be referred to as an electron injection layer. Note that the material having electron injection properties can be shared with other light-emitting devices. For example, a part of the common layer 114 can be used for the layer 114X.

[0268] Specifically, a substance having electron donating properties can be used for the layer 114X. Alternatively, a composite material of a substance having electron donating properties and a material having electron transporting properties can be used for the layer 114X. Alternatively, an electride can be used for the layer 114X. This can facilitate electron injection from the electrode 115X, for example. Alternatively, not only a material having a low work function but also a material having a high work function can be used for the electrode 115X. Alternatively, a material for the electrode 115X can be selected from a wide range of materials regardless of the work function. Specifically, Al, Ag, ITO, indium oxide-tin oxide containing silicon or silicon oxide, or the like can be used for the electrode 115X. Alternatively, the driving voltage of the light-emitting device can be reduced.

[0269] [Electron-donating substance] For example, alkali metals, alkaline earth metals, rare earth metals, or compounds thereof (oxides, halides, carbonates, etc.) can be used as the electron-donating substance. Alternatively, organic compounds such as tetrathianaphthacene (abbreviation: TTN), nickelocene, and decamethylnickelocene can also be used as the electron-donating substance.

[0270] Alkali metal compounds (including oxides, halides, and carbonates) include lithium oxide (Li ２ 0), lithium fluoride (LiF), cesium fluoride (CsF), lithium carbonate, cesium carbonate, 8-hydroxyquinolinato-lithium (abbreviation: Liq), and the like can be used.

[0271] Alkaline earth metal compounds (including oxides, halides, and carbonates) include calcium fluoride (CaF ２ ), etc. can be used.

[0272] [Configuration Example 1 of Composite Material] A composite material of a plurality of substances can be used as a material having an electron injecting property. For example, a material having an electron donating property and a material having an electron transporting property can be used as a composite material.

[0273] [Electron-Transporting Material] For example, a metal complex or an organic compound having a π-electron-deficient heteroaromatic ring skeleton can be used as the electron-transporting material.

[0274] Specifically, a material having an electron transporting property that can be used for the unit 703X can be used for the composite material.

[0275] [Configuration Example 2 of Composite Material] A microcrystalline alkali metal fluoride and a material having an electron transport property can be used for the composite material. Alternatively, a microcrystalline alkaline earth metal fluoride and a material having an electron transport property can be used for the composite material. In particular, a composite material containing 50 wt % or more of an alkali metal fluoride or an alkaline earth metal fluoride can be preferably used. Alternatively, a composite material containing an organic compound having a bipyridine skeleton can be preferably used. This can reduce the refractive index of the layer 114X. Alternatively, the external quantum efficiency of the light-emitting device can be improved.

[0276] [Structure Example 3 of Composite Material] For example, a composite material containing a first organic compound having an unshared electron pair and a first metal can be used for the layer 114X. The sum of the number of electrons in the first organic compound and the number of electrons in the first metal is preferably an odd number. The molar ratio of the first metal to 1 mole of the first organic compound is preferably 0.1 to 10, more preferably 0.2 to 2, and even more preferably 0.2 to 0.8.

[0277] This allows the first organic compound having an unshared electron pair to interact with the first metal to form a Singly Occupied Molecular Orbital (SOMO). Furthermore, when electrons are injected from the electrode 115X to the layer 114X, the barrier between them can be reduced. Furthermore, since the first metal has low reactivity with water or oxygen, the moisture resistance of the light-emitting device can be improved.

[0278] The spin density measured by electron spin resonance (ESR) is preferably 1×10 １６ spins / cm ３ or more, more preferably 5 × 10 １６ spins / cm ３ More preferably, 1×10 １７ spins / cm ３ The above composite material can be used for the layer 114X.

[0279] [Organic Compound Having an Unshared Electron Pair] For example, a material having electron transport properties can be used as an organic compound having an unshared electron pair. For example, a compound having an electron-deficient heteroaromatic ring can be used. Specifically, a compound having at least one of a pyridine ring, a diazine ring (pyrimidine ring, pyrazine ring, pyridazine ring), and a triazine ring can be used. This can reduce the driving voltage of the light-emitting device.

[0280] The organic compound having an unshared electron pair preferably has a lowest unoccupied molecular orbital (LUMO) level of −3.6 eV to −2.3 eV. Generally, the HOMO level and LUMO level of an organic compound can be estimated by cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, inverse photoelectron spectroscopy, or the like.

[0281] For example, 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), etc. can be used as the organic compound having an unshared electron pair. Note that NBPhen has a higher glass transition temperature (Tg) and is superior in heat resistance compared to BPhen.

[0282] Furthermore, for example, copper phthalocyanine, which has an odd number of electrons, can be used as the organic compound having an unshared electron pair.

[0283] [First Metal] For example, when the number of electrons in the first organic compound having an unshared electron pair is even, a composite material of a metal belonging to an odd group in the periodic table and the first organic compound can be used for the layer 114X.

[0284] For example, manganese (Mn), a Group 7 metal, cobalt (Co), a Group 9 metal, copper (Cu), silver (Ag), and gold (Au), which are Group 11 metals, and aluminum (Al) and indium (In), which are Group 13 metals, belong to odd-numbered groups in the periodic table. The elements of Group 11 have lower melting points than the elements of Groups 7 and 9, making them suitable for vacuum deposition. Ag is particularly preferred due to its low melting point.

[0285] By using Ag for the electrode 115X and the layer 114X, the adhesion between the layer 114X and the electrode 115X can be improved.

[0286] When the number of electrons in the first organic compound having the lone electron pair is odd, a composite material of the first metal and the first organic compound that belong to an even group in the periodic table can be used for the layer 114X. For example, iron (Fe), which is a metal in Group 8 of the periodic table, belongs to an even group in the periodic table.

[0287] [Electride] For example, a substance in which electrons are added to a mixed oxide of calcium and aluminum at a high concentration can be used as a material having electron injection properties.

[0288] Note that this embodiment mode can be appropriately combined with other embodiment modes described in this specification.

[0289] Embodiment 2 In this embodiment, a display device according to one embodiment of the present invention will be described with reference to FIGS.

[0290] A display device according to one embodiment of the present invention includes light-emitting devices manufactured for different light-emitting colors and is capable of full-color display.

[0291] A structure in which different light-emitting layers are fabricated or painted separately for each color light-emitting device (e.g., blue (B), green (G), and red (R)) is sometimes called an SBS (Side By Side) structure. The SBS structure allows the materials and configuration to be optimized for each light-emitting device, increasing the freedom in material and configuration selection and facilitating improvements in brightness and reliability.

[0292] When manufacturing a display device having a plurality of light-emitting devices each emitting a different light color, it is necessary to form the light-emitting layers each emitting a different light color in an island shape.

[0293] In this specification, the term "island-like" refers to a state in which two or more layers made of the same material and formed in the same process are physically separated. For example, an island-like light-emitting layer refers to a state in which the light-emitting layer is physically separated from the adjacent light-emitting layer.

[0294] For example, island-shaped light-emitting layers can be formed by vacuum deposition using a metal mask. However, this method can result in deviations in the shape and position of the island-shaped light-emitting layers from the design due to various factors, such as the accuracy of the metal mask, misalignment between the metal mask and the substrate, deflection of the metal mask, and the spread of the contours of the formed film due to vapor scattering, making it difficult to achieve high-definition and high-aperture ratio displays. Furthermore, during deposition, the contours of the layer can become blurred, resulting in thin edges. In other words, the thickness of the island-shaped light-emitting layer can vary depending on the location. Furthermore, when fabricating large, high-resolution, or high-definition display devices, there is a concern that low manufacturing yields may be caused by low dimensional accuracy of the metal mask and deformation due to heat, etc.

[0295] Therefore, when manufacturing a display device according to one embodiment of the present invention, the light-emitting layer is processed into a fine pattern by photolithography without using a shadow mask such as a metal mask. Specifically, a pixel electrode is formed for each subpixel, and then the light-emitting layer is formed over the plurality of pixel electrodes. Then, the light-emitting layer is processed by photolithography to form one island-shaped light-emitting layer for each pixel electrode. This allows the light-emitting layer to be divided into subpixels, and an island-shaped light-emitting layer to be formed for each subpixel.

[0296] When the light-emitting layer is processed into an island shape, a structure in which the light-emitting layer is processed using photolithography directly above the light-emitting layer is conceivable. In this structure, the light-emitting layer may be damaged (e.g., damaged by processing), resulting in a significant loss of reliability. Therefore, when manufacturing a display device according to one embodiment of the present invention, it is preferable to form a mask layer (also referred to as a sacrificial layer, a protective layer, or the like) on a layer (e.g., a carrier transport layer or a carrier injection layer, more specifically, an electron transport layer or an electron injection layer) located above the light-emitting layer and process the light-emitting layer into an island shape. By applying this method, a highly reliable display device can be provided. By providing another layer between the light-emitting layer and the mask layer, the light-emitting layer can be prevented from being exposed to the outermost surface during the manufacturing process of the display device, thereby reducing damage to the light-emitting layer.

[0297] In this specification, the mask film and the mask layer are each located above at least the light-emitting layer (more specifically, the layer that is processed into an island shape among the layers that make up the EL layer), and have the function of protecting the light-emitting layer during the manufacturing process.

[0298] In light-emitting devices that emit light of different colors, it is not necessary to form all layers constituting the EL layer separately; some layers can be formed in the same process. Here, examples of layers (also referred to as functional layers) included in 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). In a manufacturing method of a display device according to one embodiment of the present invention, after some layers constituting the EL layer are formed in an island shape for each color, at least a part of the mask layer is removed, and the remaining layers constituting the EL layer (sometimes referred to as a common layer) and a common electrode (also referred to as an upper electrode) are formed in common (as a single film) for the light-emitting devices of each color. For example, the carrier injection layer and the common electrode can be formed in common for the light-emitting devices of each color.

[0299] On the other hand, the carrier injection layer is often a layer with relatively high conductivity among the EL layers. Therefore, if the carrier injection layer comes into contact with the side surface of a part of the EL layer formed in an island shape or with the side surface of the pixel electrode, the light-emitting device may be short-circuited. Even when the carrier injection layer is formed in an island shape and a common electrode is formed in common to the light-emitting devices of each color, the light-emitting device may be short-circuited if the common electrode comes into contact with the side surface of the EL layer or the side surface of the pixel electrode.

[0300] Therefore, the display device of one embodiment of the present invention includes an insulating layer that covers at least the side surfaces of the island-shaped light-emitting layers. In addition, the insulating layer preferably covers part of the top surface of the island-shaped light-emitting layers.

[0301] This prevents at least a portion of the island-shaped EL layer and the pixel electrode from coming into contact with the carrier injection layer or the common electrode, thereby preventing short circuits in the light-emitting device and improving the reliability of the light-emitting device.

[0302] In a cross-sectional view, the end of the insulating layer preferably has a tapered shape with a taper angle of less than 90°. This prevents step disconnection of the common layer and common electrode provided on the insulating layer. Therefore, connection defects due to step disconnection can be suppressed. Furthermore, it is possible to suppress an increase in electrical resistance due to a local thinning of the common electrode caused by the step.

[0303] In this specification and the like, the term "step discontinuity" refers to a phenomenon in which a layer, film, or electrode is divided due to the shape of the surface on which it is formed (for example, a step or the like).

[0304] As described above, the island-shaped light-emitting layer manufactured by the method for manufacturing a display device according to one embodiment of the present invention is not formed using a fine metal mask, but is formed by forming the light-emitting layer on the entire surface and then processing it. Therefore, a high-definition display device or a display device with a high aperture ratio, which has been difficult to achieve until now, can be realized. Furthermore, since the light-emitting layer can be separately manufactured for each color, a display device with extremely vivid, high contrast, and high display quality can be realized. Furthermore, by providing a mask layer on the light-emitting layer, damage to the light-emitting layer during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-emitting device.

[0305] Furthermore, while it is difficult to achieve a spacing of less than 10 μm between adjacent light-emitting devices using, for example, a fine metal mask, a photolithography method according to one embodiment of the present invention can narrow the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes to, for example, less than 10 μm, 5 μm or less, 3 μm or less, 2 μm or less, 1.5 μm or less, 1 μm or less, or 0.5 μm or less in a process on a glass substrate. Furthermore, by using, for example, an exposure apparatus for LSIs, the spacing between adjacent light-emitting devices, adjacent EL layers, or adjacent pixel electrodes in a process on a Si wafer can be narrowed to, for example, 500 nm or less, 200 nm or less, 100 nm or less, or even 50 nm or less. This significantly reduces the area of ​​the non-light-emitting region that may exist between two light-emitting devices, enabling the aperture ratio to approach 100%. For example, in a display device of one embodiment of the present invention, the aperture ratio can be 40% or more, 50% or more, 60% or more, 70% or more, 80% or more, or even 90% or more, but less than 100%.

[0306] Increasing the aperture ratio of a display device can improve the reliability of the display device. More specifically, when the lifetime of a display device using an organic EL device and having an aperture ratio of 10% is taken as the reference, the lifetime of a display device having an aperture ratio of 20% (i.e., an aperture ratio twice as high as the reference) is approximately 3.25 times longer, and the lifetime of a display device having an aperture ratio of 40% (i.e., an aperture ratio four times as high as the reference) is approximately 10.6 times longer. As such, as the aperture ratio increases, the current density flowing through the organic EL device can be reduced, thereby improving the lifetime of the display device. In the display device of one embodiment of the present invention, the aperture ratio can be increased, thereby improving the display quality of the display device. Furthermore, as the aperture ratio of the display device increases, an excellent effect is achieved, such as a significant improvement in the reliability (particularly the lifetime) of the display device.

[0307] Furthermore, the pattern of the light-emitting layer itself (also known as the processing size) can be made much smaller than when a fine metal mask is used. Furthermore, for example, when a metal mask is used to separately fabricate light-emitting layers, thickness variations occur between the center and edges of the light-emitting layer, resulting in a smaller effective area that can be used as a light-emitting region relative to the area of ​​the light-emitting layer. On the other hand, the above-described fabrication method processes a film formed to a uniform thickness, allowing island-shaped light-emitting layers to be formed with a uniform thickness. Therefore, even with a fine pattern, almost the entire area can be used as a light-emitting region. This allows the fabrication of a display device that combines high definition and a high aperture ratio. Furthermore, the display device can be made smaller and lighter.

[0308] Specifically, the resolution of the display device of one embodiment of the present invention can be, for example, 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and still more preferably 6000 ppi or more, and can be 20000 ppi or less, or 30000 ppi or less.

[0309] In this embodiment, a cross-sectional structure of a display device according to one embodiment of the present invention will be mainly described, and a manufacturing method of the display device according to one embodiment of the present invention will be described in detail in Embodiment 3.

[0310] FIG. 3A shows a top view of the display device 100. The display device 100 has a display section in which a plurality of pixels 110 are arranged, and a connection section 140 outside the display section. A plurality of sub-pixels are arranged in a matrix in the display section. FIG. 3A shows two rows and six columns of sub-pixels, which together form a two-row, two-column pixel. The connection section 140 can also be called a cathode contact section.

[0311] 3A corresponds to the top surface shape of the light-emitting region. In this specification and the like, the top surface shape refers to the shape in a plan view, that is, the shape seen from above.

[0312] The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle.

[0313] Furthermore, the circuit layout constituting the subpixel is not limited to the range of the subpixel shown in Fig. 3A and may be arranged outside the range. For example, the transistor included in the subpixel 110a may be located within the range of the subpixel 110b shown in Fig. 3A, or part or all of the transistor may be located outside the range of the subpixel 110a.

[0314] 3A shows the subpixels 110a, 110b, and 110c as having the same or approximately the same aperture ratio (which can also be referred to as the size or size of the light-emitting region), but this is not a limitation of one embodiment of the present invention. The aperture ratios of the subpixels 110a, 110b, and 110c can be determined as appropriate. The aperture ratios of the subpixels 110a, 110b, and 110c may be different from one another, or two or more of the subpixels 110a, 110b, and 110c may be the same or approximately the same.

[0315] A stripe arrangement is applied to the pixel 110 shown in FIG. 3A . The pixel 110 shown in FIG. 3A is composed of three subpixels, 110a, 110b, and 110c. The subpixels 110a, 110b, and 110c each have a light-emitting device that emits light of a different color. Examples of the subpixels 110a, 110b, and 110c include subpixels of three colors: red (R), green (G), and blue (B), and subpixels of three colors: yellow (Y), cyan (C), and magenta (M). The number of types of subpixels is not limited to three, and may be four or more. Examples of four subpixels include subpixels of four colors: R, G, B, and white (W), subpixels of four colors: R, G, B, and Y, and subpixels of R, G, B, and infrared (IR).

[0316] In this specification and the like, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly (see FIG. 3A ). FIG. 3A shows an example in which subpixels of different colors are arranged side by side in the X direction, and subpixels of the same color are arranged side by side in the Y direction.

[0317] 3A shows an example in which the connection portion 140 is located below the display portion when viewed from above, but the location of the connection portion 140 is not particularly limited. The connection portion 140 only needs to be located in at least one of the upper, right, left, and lower sides of the display portion when viewed from above, and may be located so as to surround all four sides of the display portion. The shape of the upper surface of the connection portion 140 may be strip-shaped, L-shaped, U-shaped, frame-shaped, or the like. Furthermore, the connection portion 140 may be singular or plural.

[0318] Fig. 3B shows a cross-sectional view taken along dashed line X1-X2 in Fig. 3A. Figs. 4A and 4B show enlarged views of a portion of the cross-sectional view shown in Fig. 3B. Figs. 5 to 8 show modifications of Fig. 4. Figs. 9A and 9B show cross-sectional views taken along dashed line Y1-Y2 in Fig. 3A.

[0319] 3B , in display device 100, an insulating layer is provided on transistor-containing layer 101, light-emitting devices 130a, 130b, and 130c are provided on the insulating layer, and a protective layer 131 is provided to cover these light-emitting devices. Substrate 120 is bonded to protective layer 131 with resin layer 122. In addition, insulating layer 125 and insulating layer 127 on insulating layer 125 are provided in the regions between adjacent light-emitting devices.

[0320] 3B shows multiple cross sections of insulating layer 125 and insulating layer 127, but when display device 100 is viewed from above, insulating layer 125 and insulating layer 127 are each connected to one another. In other words, display device 100 can be configured to have, for example, one insulating layer 125 and one insulating layer 127. Note that display device 100 may have multiple insulating layers 125 that are separated from one another, or may have multiple insulating layers 127 that are separated from one another.

[0321] The display device of one embodiment of the present invention may be any of a top emission type that emits light in a direction opposite to a substrate on which a light-emitting device is formed, a bottom emission type that emits light toward a substrate on which a light-emitting device is formed, and a dual emission type that emits light from both sides.

[0322] The layer 101 including transistors can have, for example, a stacked structure in which a plurality of transistors are provided on a substrate and an insulating layer is provided to cover these transistors. The insulating layer over the transistors may have a single-layer structure or a stacked structure. Figure 3B shows the insulating layers over the transistors, including an insulating layer 255a, an insulating layer 255b over the insulating layer 255a, and an insulating layer 255c over the insulating layer 255b. These insulating layers may have recesses between adjacent light-emitting devices. Figure 3B and other figures show an example in which a recess is provided in the insulating layer 255c. Note that the insulating layers over the transistors (insulating layers 255a to 255c) may also be considered as part of the layer 101 including transistors.

[0323] The insulating layers 255a, 255b, and 255c can each be suitably formed using various inorganic insulating films such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, and a nitride oxide insulating film. The insulating layers 255a and 255c are preferably formed using an oxide insulating film or an oxynitride insulating film such as a silicon oxide film, a silicon oxynitride film, or an aluminum oxide film. The insulating layer 255b is preferably formed using a nitride insulating film or a nitride oxide insulating film such as a silicon nitride film or a silicon nitride oxide film. More specifically, the insulating layers 255a and 255c are preferably formed using silicon oxide films, and the insulating layer 255b is preferably formed using a silicon nitride film. The insulating layer 255b preferably functions as an etching protective film.

[0324] In this specification and the like, an oxynitride refers to a material whose composition contains more oxygen than nitrogen, and a nitride oxide refers to a material whose composition contains more nitrogen than oxygen. For example, silicon oxynitride refers to a material whose composition contains more oxygen than nitrogen, and silicon nitride oxide refers to a material whose composition contains more nitrogen than oxygen.

[0325] A structural example of the layer 101 including a transistor will be described later in Embodiment 5.

[0326] The light emitting devices 130a, 130b, and 130c each emit light of a different color, and preferably emit light of three colors, for example, red (R), green (G), and blue (B).

[0327] As the light-emitting device, for example, an OLED (organic light-emitting diode) or a QLED (quantum-dot light-emitting diode) is preferably used. Examples of the light-emitting material contained in the light-emitting device include a fluorescent material, a phosphorescent material, an inorganic compound (such as a quantum dot material), and a thermally activated delayed fluorescence material (TADF material). Furthermore, an LED such as a micro LED (light-emitting diode) can also be used as the light-emitting device.

[0328] The light emitting device can emit light of infrared, red, green, blue, cyan, magenta, yellow, white, etc. The color purity can be improved by providing the light emitting device with a microcavity structure.

[0329] For the structure and materials of the light-emitting device, reference can be made to Embodiment Mode 6.

[0330] Of the pair of electrodes that a light-emitting device has, one electrode functions as an anode and the other electrode functions as a cathode. In the following, an example in which the pixel electrode functions as the anode and the common electrode functions as the cathode will be described.

[0331] The light-emitting device 130a has a pixel electrode 111a on an insulating layer 255c, an island-shaped first layer 113a on the pixel electrode 111a, a common layer 114 on the island-shaped first layer 113a, and a common electrode 115 on the common layer 114. In the light-emitting device 130a, the first layer 113a and the common layer 114 can be collectively referred to as an EL layer.

[0332] The light-emitting device 130b has a pixel electrode 111b on an insulating layer 255c, an island-shaped second layer 113b on the pixel electrode 111b, a common layer 114 on the island-shaped second layer 113b, and a common electrode 115 on the common layer 114. In the light-emitting device 130b, the second layer 113b and the common layer 114 can be collectively referred to as an EL layer.

[0333] The light-emitting device 130c has a pixel electrode 111c on an insulating layer 255c, an island-shaped third layer 113c on the pixel electrode 111c, a common layer 114 on the island-shaped third layer 113c, and a common electrode 115 on the common layer 114. In the light-emitting device 130c, the third layer 113c and the common layer 114 can be collectively referred to as an EL layer.

[0334] In this specification and the like, among the EL layers included in the light-emitting devices, layers provided in an island shape for each light-emitting device are referred to as the first layer 113a, the second layer 113b, or the third layer 113c, and a layer shared by a plurality of light-emitting devices is referred to as the common layer 114. Note that in this specification and the like, the first layer 113a, the second layer 113b, and the third layer 113c may be referred to as an island-shaped EL layer, an EL layer formed in an island shape, or the like, without including the common layer 114.

[0335] The first layer 113a, the second layer 113b, and the third layer 113c are separated from one another. By providing an EL layer in an island shape for each light-emitting device, leakage current between adjacent light-emitting devices can be suppressed. This makes it possible to prevent crosstalk caused by unintended light emission and realize a display device with extremely high contrast. In particular, a display device with high current efficiency at low luminance can be realized.

[0336] The pixel electrodes 111a, 111b, and 111c preferably have tapered edges. Specifically, the pixel electrodes 111a, 111b, and 111c preferably have tapered edges with a taper angle of less than 90°. When the edges of these pixel electrodes have tapered edges, the first layer 113a, the second layer 113b, and the third layer 113c provided along the side surfaces of the pixel electrodes also have tapered edges (corresponding to inclined portions described later). Tapered edges of the pixel electrodes can improve the coverage of the EL layer provided along the side surfaces of the pixel electrodes. Tapered edges of the pixel electrodes are also preferable because they facilitate the removal of foreign matter (e.g., dust or particles) during the manufacturing process by cleaning or other processes.

[0337] In FIG. 3B , no insulating layer covering the upper end of the pixel electrode 111a is provided between the pixel electrode 111a and the first layer 113a. Furthermore, no insulating layer covering the upper end of the pixel electrode 111b is provided between the pixel electrode 111b and the second layer 113b. This allows the distance between adjacent light-emitting devices to be extremely narrow. This allows for a high-definition or high-resolution display device. Furthermore, a mask for forming the insulating layer is no longer necessary, thereby reducing the manufacturing cost of the display device.

[0338] Furthermore, by using a structure in which an insulating layer covering an edge of the pixel electrode is not provided between the pixel electrode and the EL layer, in other words, by using a structure in which an insulating layer is not provided between the pixel electrode and the EL layer, light from the EL layer can be efficiently extracted. Therefore, the display device of one embodiment of the present invention can have extremely low viewing angle dependence. By reducing the viewing angle dependence, the visibility of images in the display device can be improved. For example, in the display device of one embodiment of the present invention, the viewing angle (the maximum angle at which a certain contrast ratio is maintained when the screen is viewed from an oblique direction) can be set to a range of 100° to less than 180°, preferably 150° to 170°. Note that the above viewing angle can be applied to both the vertical and horizontal directions.

[0339] The light-emitting device of the present embodiment may have a single structure (a structure having only one light-emitting unit) or a tandem structure (a structure having multiple light-emitting units). The light-emitting unit has at least one light-emitting layer.

[0340] The first layer 113 a, the second layer 113 b, and the third layer 113 c each include at least a light-emitting layer. For example, it is preferable that the first layer 113 a includes a light-emitting layer that emits red light, the second layer 113 b includes a light-emitting layer that emits green light, and the third layer 113 c includes a light-emitting layer that emits blue light.

[0341] In addition, when a light-emitting device with a tandem structure is used, it is preferable that the first layer 113a has a structure having a plurality of light-emitting units that emit red light, the second layer 113b has a structure having a plurality of light-emitting units that emit green light, and the third layer 113c has a structure having a plurality of light-emitting units that emit blue light. It is preferable to provide a charge generation layer between each of the light-emitting units.

[0342] Furthermore, the first layer 113a, the second layer 113b, and the third layer 113c may each have one or more of 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.

[0343] For example, the first layer 113a, the second layer 113b, and the third layer 113c may each include a hole injection layer, a hole transport layer, a light-emitting layer, and an electron transport layer in this order. Alternatively, an electron blocking layer may be provided between the hole transport layer and the light-emitting layer. Alternatively, an electron injection layer may be provided on the electron transport layer.

[0344] For example, the first layer 113 a, the second layer 113 b, and the third layer 113 c may each include an electron injection layer, an electron transport layer, a light-emitting layer, and a hole transport layer in this order. Alternatively, a hole blocking layer may be provided between the electron transport layer and the light-emitting layer. Alternatively, a hole injection layer may be provided on the hole transport layer.

[0345] The first layer 113a, the second layer 113b, and the third layer 113c preferably include a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. The surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are exposed during the manufacturing process of the display device. Therefore, by providing the carrier transport layer on the light-emitting layer, the light-emitting layer can be prevented from being exposed to the outermost surface, and damage to the light-emitting layer can be reduced. This can improve the reliability of the light-emitting device.

[0346] The first layer 113a, the second layer 113b, and the third layer 113c each have, for example, a first light-emitting unit, a charge generation layer, and a second light-emitting unit stacked in this order over a pixel electrode.

[0347] The second light-emitting unit preferably has a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer. Since the surface of the second light-emitting unit is exposed during the manufacturing process of the display device, providing a carrier transport layer on the light-emitting layer prevents the light-emitting layer from being exposed to the outermost surface, thereby reducing damage to the light-emitting layer. This improves the reliability of the light-emitting device. Note that when three or more light-emitting units are included, the uppermost light-emitting unit preferably has a light-emitting layer and a carrier transport layer (electron transport layer or hole transport layer) on the light-emitting layer.

[0348] The common layer 114 may include, for example, an electron injection layer or a hole injection layer. Alternatively, the common layer 114 may include a stack of an electron transport layer and an electron injection layer, or a stack of a hole transport layer and a hole injection layer. The common layer 114 is shared by the light-emitting devices 130 a, 130 b, and 130 c.

[0349] 3B shows an example in which the edge of the first layer 113a is positioned outside the edge of the pixel electrode 111a. Note that although the pixel electrode 111a and the first layer 113a are taken as an example for description, the same can be said for the pixel electrode 111b and the second layer 113b, and the pixel electrode 111c and the third layer 113c.

[0350] 3B, the first layer 113a is formed so as to cover the edge of the pixel electrode 111a. With this configuration, it is possible to use the entire upper surface of the pixel electrode as a light-emitting region, which makes it easier to increase the aperture ratio compared to a configuration in which the edge of the island-shaped EL layer is located inside the edge of the pixel electrode.

[0351] Furthermore, by covering the side surfaces of the pixel electrodes with the EL layer, contact between the pixel electrodes and the common electrode 115 can be prevented, thereby preventing short circuits in the light-emitting device. Furthermore, the distance between the light-emitting region of the EL layer (i.e., the region overlapping with the pixel electrode) and the edge of the EL layer can be increased. Since the edge of the EL layer may be damaged by processing, using an area away from the edge of the EL layer as the light-emitting region may improve the reliability of the light-emitting device.

[0352] The common electrode 115 is shared by the light-emitting devices 130a, 130b, and 130c. The common electrode 115 shared by the plurality of light-emitting devices is electrically connected to a conductive layer 123 provided in a connection portion 140 (see FIGS. 9A and 9B). The conductive layer 123 is preferably made of the same material and formed in the same process as the pixel electrodes 111a, 111b, and 111c.

[0353] 9A shows an example in which a common layer 114 is provided on the conductive layer 123, and the conductive layer 123 and the common electrode 115 are electrically connected to each other through the common layer 114. The common layer 114 does not need to be provided in the connection portion 140. In FIG. 9B, the conductive layer 123 and the common electrode 115 are directly connected to each other. For example, by using a mask for defining a film formation area (also called an area mask or a rough metal mask to distinguish it from a fine metal mask), the regions where the common layer 114 and the common electrode 115 are formed can be changed.

[0354] 3B , a mask layer 118a is located over the first layer 113a of the light-emitting device 130a, a mask layer 118b is located over the second layer 113b of the light-emitting device 130b, and a mask layer 118c is located over the third layer 113c of the light-emitting device 130c. The mask layer 118a is a mask layer that is provided in contact with the top surface of the first layer 113a when the first layer 113a is processed, and a portion of the mask layer remains. Similarly, the mask layer 118b is a mask layer that is provided during the formation of the second layer 113b, and the mask layer 118c is a mask layer that is provided during the formation of the third layer 113c, and a portion of the mask layer remains. In this manner, a display device according to one embodiment of the present invention may have a mask layer used to protect an EL layer during its fabrication remaining. The mask layers 118a to 118c may be made of the same material or different materials, and may hereinafter be collectively referred to as the mask layers 118.

[0355] In FIG. 3B , one end of the mask layer 118a is aligned or approximately aligned with the end of the first layer 113a, and the other end of the mask layer 118a is located on the first layer 113a. Here, the other end of the mask layer 118a preferably overlaps the first layer 113a and the pixel electrode 111a. In this case, the other end of the mask layer 118a is likely to be formed on a flat or approximately flat surface of the first layer 113a. The same applies to the mask layers 118b and 118c. Furthermore, the mask layer 118 remains, for example, between the top surface of the island-shaped EL layer (the first layer 113a, the second layer 113b, or the third layer 113c) and the insulating layer 125. The mask layer will be described in detail in Embodiment 3.

[0356] In addition, when the edges are aligned or approximately aligned, and when the top surface shapes are the same or approximately aligned, it can be said that at least a portion of the contours of the stacked layers overlap when viewed from above. For example, this includes cases where the upper and lower layers are processed using the same mask pattern or a portion of the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or outside the lower layer. In these cases, it is also said that the edges are approximately aligned, or the top surface shapes are approximately aligned.

[0357] The side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c are covered with the insulating layer 125. The insulating layer 127 overlaps with (can also be said to cover) the side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c with the insulating layer 125 interposed therebetween.

[0358] Furthermore, a portion of the upper surface of each of the first layer 113a, the second layer 113b, and the third layer 113c is covered with a mask layer 118. The insulating layer 125 and the insulating layer 127 overlap a portion of the upper surface of each of the first layer 113a, the second layer 113b, and the third layer 113c via the mask layer 118. Note that the upper surfaces of each of the first layer 113a, the second layer 113b, and the third layer 113c are not limited to the upper surface of the flat portion that overlaps the upper surface of the pixel electrode, but may also include the upper surfaces of the inclined portion and flat portion (see region 103 in FIG. 8A ) located outside the upper surface of the pixel electrode.

[0359] By covering part of the top surfaces and side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c with at least one of the insulating layer 125, the insulating layer 127, and the mask layer 118, the common layer 114 (or the common electrode 115) is prevented from contacting the side surfaces of the pixel electrodes 111a, 111b, and 111c, the first layer 113a, the second layer 113b, and the third layer 113c, thereby preventing short circuits in the light-emitting device and improving the reliability of the light-emitting device.

[0360] 3B, the first to third layers 113a to 113c are all shown to have the same thickness, but the present invention is not limited to this. The first to third layers 113a to 113c may have different thicknesses. For example, it is preferable to set the thickness of each layer in accordance with the optical path length that enhances the light emitted by each of the first to third layers 113a to 113c. This allows for a microcavity structure to be realized, and the color purity of each light-emitting device to be improved.

[0361] The insulating layer 125 is preferably in contact with the side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c (see the end portions of the first layer 113a and the second layer 113b and the areas in their vicinity surrounded by dashed lines in FIG. 4A ). The insulating layer 125 being in contact with the first layer 113a, the second layer 113b, and the third layer 113c can prevent the first layer 113a, the second layer 113b, and the third layer 113c from peeling off. The insulating layer 125 being in close contact with the first layer 113a, the second layer 113b, or the third layer 113c can fix or bond the adjacent first layers 113a, etc., by the insulating layer 125. This can improve the reliability of the light-emitting device. Furthermore, the manufacturing yield of the light-emitting device can be increased.

[0362] 3B , the insulating layer 125 and the insulating layer 127 cover part of the top surface and both the side surfaces of the first layer 113 a, the second layer 113 b, and the third layer 113 c, which can further prevent peeling of the EL layer and improve the reliability of the light-emitting device and the manufacturing yield of the light-emitting device.

[0363] 3B shows an example in which a stacked structure of the first layer 113a, the mask layer 118a, the insulating layer 125, and the insulating layer 127 is located on an end of the pixel electrode 111a. Similarly, a stacked structure of the second layer 113b, the mask layer 118b, the insulating layer 125, and the insulating layer 127 is located on an end of the pixel electrode 111b, and a stacked structure of the third layer 113c, the mask layer 118c, the insulating layer 125, and the insulating layer 127 is located on an end of the pixel electrode 111c.

[0364] 3B shows a configuration in which the edge of the pixel electrode 111a is covered with the first layer 113a, and the insulating layer 125 is in contact with the side surface of the first layer 113a. Similarly, the edge of the pixel electrode 111b is covered with the second layer 113b, the edge of the pixel electrode 111c is covered with the third layer 113c, and the insulating layer 125 is in contact with the side surface of the second layer 113b and the side surface of the third layer 113c.

[0365] The insulating layer 127 is provided over the insulating layer 125 so as to fill recesses in the insulating layer 125. The insulating layer 127 can overlap with part of the top surface and side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c with the insulating layer 125 interposed therebetween. The insulating layer 127 preferably covers at least part of the side surfaces of the insulating layer 125.

[0366] By providing the insulating layers 125 and 127, the spaces between the adjacent island-shaped layers can be filled, which reduces large unevenness in height on the surface on which layers (for example, the carrier injection layer, the common electrode, etc.) are formed on the island-shaped layers, thereby making the surface flatter. Therefore, the coverage of the carrier injection layer, the common electrode, etc. can be improved.

[0367] The common layer 114 and the common electrode 115 are provided over the first layer 113a, the second layer 113b, the third layer 113c, the mask layer 118, the insulating layer 125, and the insulating layer 127. Before the insulating layer 125 and the insulating layer 127 are provided, a step is generated between a region where the pixel electrode and the island-shaped EL layer are provided and a region where the pixel electrode and the island-shaped EL layer are not provided (a region between light-emitting devices). In the display device of one embodiment of the present invention, the insulating layer 125 and the insulating layer 127 can flatten the step, thereby improving the coverage of the common layer 114 and the common electrode 115. Therefore, poor connection due to disconnection can be suppressed. Furthermore, the step can suppress an increase in electrical resistance due to a local thinning of the common electrode 115.

[0368] The upper surface of the insulating layer 127 preferably has a highly flat shape, but may have a convex portion, a convex curved surface, a concave curved surface, or a concave portion. For example, the upper surface of the insulating layer 127 preferably has a highly flat, smooth convex curved surface shape.

[0369] Next, examples of materials for the insulating layer 125 and the insulating layer 127 will be described.

[0370] The insulating layer 125 can be an insulating layer containing an inorganic material. For example, an inorganic insulating film such as an insulating oxide film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film can be used for the insulating layer 125. The insulating layer 125 may have a single-layer structure or a stacked-layer structure. Examples of oxide insulating films include a silicon oxide film, an aluminum oxide film, a magnesium oxide film, an indium gallium zinc oxide film, a gallium oxide film, a germanium oxide film, an yttrium oxide film, a zirconium oxide film, a lanthanum oxide film, a neodymium oxide film, a hafnium oxide film, and a tantalum oxide film. Examples of nitride insulating films include a silicon nitride film and an aluminum nitride film. Examples of oxynitride insulating films include a silicon oxynitride film and an aluminum oxynitride film. Examples of nitride oxide insulating films include a silicon nitride oxide film and an aluminum nitride oxide film. In particular, aluminum oxide is preferable because it has a high etching selectivity with respect to the EL layer and has a function of protecting the EL layer in the formation of the insulating layer 127 described later. In particular, by using an inorganic insulating film such as an aluminum oxide film, a hafnium oxide film, or a silicon oxide film formed by atomic layer deposition (ALD) as the insulating layer 125, it is possible to form an insulating layer 125 that has few pinholes and has an excellent function of protecting the EL layer. The insulating layer 125 may also have a stacked structure of a film formed by ALD and a film formed by sputtering. For example, the insulating layer 125 may have a stacked structure of an aluminum oxide film formed by ALD and a silicon nitride film formed by sputtering.

[0371] The insulating layer 125 preferably functions as a barrier insulating layer against at least one of water and oxygen. The insulating layer 125 preferably has a function of suppressing diffusion of at least one of water and oxygen. The insulating layer 125 preferably has a function of capturing or fixing (also referred to as gettering) at least one of water and oxygen.

[0372] In this specification and the like, a barrier insulating layer refers to an insulating layer having barrier properties. In addition, in this specification and the like, the barrier properties refer to a function of suppressing the diffusion of a corresponding substance (also referred to as low permeability) or a function of capturing or fixing (gettering) a corresponding substance.

[0373] The insulating layer 125 has a function as a barrier insulating layer or a gettering function, which makes it possible to suppress the intrusion of impurities (typically, at least one of water and oxygen) that may diffuse into each light-emitting device from the outside. With this configuration, it is possible to provide a highly reliable light-emitting device and further a highly reliable display device.

[0374] The insulating layer 125 preferably has a low impurity concentration. This can prevent impurities from entering the EL layer from the insulating layer 125 and causing deterioration of the EL layer. Furthermore, a low impurity concentration in the insulating layer 125 can improve the barrier properties against at least one of water and oxygen. For example, it is desirable that the insulating layer 125 has a sufficiently low hydrogen concentration or a sufficiently low carbon concentration, or preferably both of them.

[0375] The insulating layer 125 and the mask layers 118a, 118b, and 118c can be made of the same material. In this case, the boundary between the insulating layer 125 and any of the mask layers 118a, 118b, and 118c may become unclear and indistinguishable. Therefore, any of the mask layers 118a, 118b, and 118c and the insulating layer 125 may be recognized as a single layer. In other words, one layer may be provided in contact with a portion of the top surface and side surfaces of each of the first layer 113a, the second layer 113b, and the third layer 113c, and the insulating layer 127 may be observed to cover at least a portion of the side surfaces of the single layer.

[0376] The insulating layer 127 provided on the insulating layer 125 has the function of flattening large unevenness of the insulating layer 125 formed between adjacent light-emitting devices. In other words, the insulating layer 127 has the effect of improving the flatness of the surface on which the common electrode 115 is formed.

[0377] An insulating layer containing an organic material can be suitably used as the insulating layer 127. As the organic material, a photosensitive organic resin, for example, a photosensitive acrylic resin, is preferably used. Note that in this specification and the like, the term "acrylic resin" does not refer only to polymethacrylic acid ester or methacrylic resin, but may refer to all acrylic polymers in a broad sense.

[0378] The insulating layer 127 may also be made of acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimideamide resin, silicone resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, or precursors of these resins. The insulating layer 127 may also be made of organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin. The photosensitive resin may also be a photoresist. Either a positive-type material or a negative-type material may be used as the photosensitive organic resin.

[0379] The insulating layer 127 may be made of a material that absorbs visible light. The insulating layer 127 absorbs light emitted from the light-emitting device, thereby preventing light from leaking from the light-emitting device to an adjacent light-emitting device through the insulating layer 127 (stray light). This improves the display quality of the display device. Furthermore, since the display quality can be improved without using a polarizing plate in the display device, the display device can be made lighter and thinner.

[0380] Examples of materials that absorb visible light include materials containing pigments such as black, materials containing dyes, light-absorbing resin materials (e.g., polyimide), and resin materials that can be used for color filters (color filter materials). In particular, using a resin material in which two or more color filter materials are laminated or mixed is preferable because it can enhance the visible light blocking effect. In particular, mixing three or more color filter materials makes it possible to form a black or nearly black resin layer.

[0381] Furthermore, it is preferable that the material used for the insulating layer 127 has a low volume shrinkage rate. This makes it easy to form the insulating layer 127 in a desired shape. It is also preferable that the insulating layer 127 has a low volume shrinkage rate after curing. This makes it easier to maintain the shape of the insulating layer 127 in various processes after its formation. Specifically, the volume shrinkage rate of the insulating layer 127 after thermal curing, after photocuring, or after photocuring and thermal curing is preferably 10% or less, more preferably 5% or less, and even more preferably 1% or less. Here, the volume shrinkage rate can be either one of the volume shrinkage rate due to light irradiation and the volume shrinkage rate due to heating, or the sum of both.

[0382] Next, the structure of the insulating layer 127 and its vicinity will be described using FIGS. 4A and 4B . FIG. 4A is an enlarged cross-sectional view of the insulating layer 127 between the light-emitting devices 130a and 130b and a region including the periphery thereof. The following description will be given using the insulating layer 127 between the light-emitting devices 130a and 130b as an example, but the same applies to the insulating layer 127 between the light-emitting devices 130b and 130c, and the insulating layer 127 between the light-emitting devices 130c and 130a. FIG. 4B is an enlarged view of the end of the insulating layer 127 on the second layer 113b and its vicinity, as shown in FIG. 4A . The following description will sometimes be given using the end of the insulating layer 127 on the second layer 113b as an example, but the same applies to the end of the insulating layer 127 on the first layer 113a and the end of the insulating layer 127 on the third layer 113c.

[0383] As shown in FIG. 4A , a first layer 113a is provided covering the pixel electrode 111a, and a second layer 113b is provided covering the pixel electrode 111b. A mask layer 118a is provided in contact with a portion of the top surface of the first layer 113a, and a mask layer 118b is provided in contact with a portion of the top surface of the second layer 113b. An insulating layer 125 is provided in contact with the top and side surfaces of the mask layer 118a, the side surfaces of the first layer 113a, the top surface of the insulating layer 255c, the top and side surfaces of the mask layer 118b, and the side surfaces of the second layer 113b. The insulating layer 125 also covers a portion of the top surface of the first layer 113a and a portion of the top surface of the second layer 113b. An insulating layer 127 is provided in contact with the top surface of the insulating layer 125. Furthermore, the insulating layer 127 overlaps with a part of the upper surface and the side surface of the first layer 113a and a part of the upper surface and the side surface of the second layer 113b via the insulating layer 125, and is in contact with at least a part of the side surface of the insulating layer 125. A common layer 114 is provided to cover the first layer 113a, the mask layer 118a, the second layer 113b, the mask layer 118b, the insulating layer 125, and the insulating layer 127, and a common electrode 115 is provided on the common layer 114.

[0384] 4B , the insulating layer 127 preferably has a tapered shape at its end with a taper angle θ1 in a cross-sectional view of the display device. The taper angle θ1 is the angle between the side surface of the insulating layer 127 and the substrate surface. However, the taper angle θ1 is not limited to the substrate surface, and may be the angle between the side surface of the insulating layer 127 and the upper surface of the flat portion of the second layer 113b or the upper surface of the flat portion of the pixel electrode 111b.

[0385] The taper angle θ1 of the insulating layer 127 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less. By forming the end of the insulating layer 127 in such a forward tapered shape, the common layer 114 and the common electrode 115 provided on the insulating layer 127 can be formed with good coverage, and the occurrence of discontinuities or local thinning can be suppressed. This improves the in-plane uniformity of the common layer 114 and the common electrode 115, thereby improving the display quality of the display device.

[0386] 4A , in a cross-sectional view of the display device, the upper surface of the insulating layer 127 preferably has a convex curved shape. The convex curved shape of the upper surface of the insulating layer 127 preferably bulges gently toward the center. Furthermore, the convex curved portion at the center of the upper surface of the insulating layer 127 preferably has a shape that is continuously connected to the tapered portions at the end. By forming the insulating layer 127 in this shape, the common layer 114 and the common electrode 115 can be formed with good coverage over the entire upper surface of the insulating layer 127.

[0387] 4B , the end of the insulating layer 127 is preferably positioned outside the end of the insulating layer 125. This reduces the unevenness of the surface on which the common layer 114 and the common electrode 115 are formed, and improves the coverage of the common layer 114 and the common electrode 115.

[0388] 4B , the insulating layer 125 preferably has a tapered shape at its end with a taper angle θ2 in a cross-sectional view of the display device. The taper angle θ2 is the angle between the side surface of the insulating layer 125 and the substrate surface. However, the taper angle θ2 is not limited to the substrate surface, and may be the angle between the side surface of the insulating layer 125 and the upper surface of the flat portion of the second layer 113b or the upper surface of the flat portion of the pixel electrode 111b.

[0389] The taper angle θ2 of the insulating layer 125 is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less.

[0390] 4B , the mask layer 118b preferably has a tapered shape at its end with a taper angle θ3 in a cross-sectional view of the display device. The taper angle θ3 is the angle between the side surface of the mask layer 118b and the substrate surface. However, the taper angle θ3 is not limited to the substrate surface, and may be the angle between the top surface of the flat portion of the second layer 113b or the top surface of the flat portion of the pixel electrode 111b and the side surface of the insulating layer 127.

[0391] The taper angle θ3 of the mask layer 118b is less than 90°, preferably 60° or less, more preferably 45° or less, and even more preferably 20° or less. By forming the mask layer 118b in such a forward tapered shape, the common layer 114 and the common electrode 115 provided on the mask layer 118b can be formed with good coverage.

[0392] The ends of the mask layers 118a and 118b are preferably located outside the ends of the insulating layer 125. This reduces the unevenness of the surfaces on which the common layer 114 and the common electrode 115 are formed, and improves the coverage of the common layer 114 and the common electrode 115.

[0393] As will be described in detail in Embodiment 3, if the insulating layer 125 and the mask layer 118 are etched at the same time, side etching may cause the insulating layer 125 and the mask layer below the edge of the insulating layer 127 to disappear, forming a cavity. Such a cavity may cause unevenness on the surface on which the common layer 114 and the common electrode 115 are formed, making the common layer 114 and the common electrode 115 more likely to break apart. Therefore, by performing the etching process in two stages and performing a heat treatment between the two etchings, even if a cavity is formed in the first etching process, the heat treatment deforms the insulating layer 127, thereby filling the cavity. Furthermore, since the second etching process etches a thin film, the amount of side etching is reduced, making it less likely that a cavity will form. Even if a cavity does form, it can be made extremely small. Therefore, unevenness on the surface on which the common layer 114 and the common electrode 115 are formed can be suppressed, and step-off of the common layer 114 and the common electrode 115 can be suppressed. Since the etching process is performed twice in this manner, the taper angles θ2 and θ3 may be different from each other. Alternatively, the taper angles θ2 and θ3 may be the same. Alternatively, the taper angles θ2 and θ3 may be smaller than the taper angle θ1.

[0394] The insulating layer 127 may cover at least a portion of the side surface of the mask layer 118a and at least a portion of the side surface of the mask layer 118b. For example, FIG. 4B shows an example in which the insulating layer 127 contacts and covers the inclined surface located at the end of the mask layer 118b formed by the first etching process, while the inclined surface located at the end of the mask layer 118b formed by the second etching process is exposed. These two inclined surfaces may be distinguishable because they have different taper angles. Alternatively, there may be little difference in the taper angles of the side surfaces formed by the two etching processes, making them indistinguishable.

[0395] 5A and 5B also show an example in which the insulating layer 127 covers the entire side surfaces of the mask layer 118a and the entire side surfaces of the mask layer 118b. Specifically, in FIG. 5B, the insulating layer 127 contacts and covers both of the two inclined surfaces. This is preferable because it further reduces the unevenness of the surfaces on which the common layer 114 and the common electrode 115 are formed. FIG. 5B also shows an example in which the end of the insulating layer 127 is located outside the end of the mask layer 118b. As shown in FIG. 4B, the end of the insulating layer 127 may be located inside the end of the mask layer 118b, or may be aligned or approximately aligned with the end of the mask layer 118b. Also, as shown in FIG. 5B, the insulating layer 127 may contact the second layer 113b.

[0396] In addition, when the edges are aligned or approximately aligned, and when the top surface shapes are the same or approximately aligned, it can be said that at least a portion of the contours of the stacked layers overlap when viewed from above. For example, this includes cases where the upper and lower layers are processed using the same mask pattern or a portion of the same mask pattern. However, strictly speaking, the contours may not overlap, and the upper layer may be located inside the lower layer, or outside the lower layer. In these cases, it is also said that the edges are approximately aligned, or the top surface shapes are approximately aligned.

[0397] 6A, 6B, 7A, and 7B show examples in which the insulating layer 127 has a concave curved shape (also referred to as a constricted portion, a recessed portion, a dent, a depression, or the like) on the side surface. Depending on the material and forming conditions (heating temperature, heating time, heating atmosphere, and the like) of the insulating layer 127, the concave curved shape may be formed on the side surface of the insulating layer 127.

[0398] 6A and 6B show an example in which the insulating layer 127 covers a part of the side surface of the mask layer 118b and the remaining part of the side surface of the mask layer 118b is exposed. Figures 7A and 7B show an example in which the insulating layer 127 contacts and covers the entire side surface of the mask layer 118a and the entire side surface of the mask layer 118b.

[0399] 5 to 7, it is preferable that the taper angles θ1 to θ3 are in the above ranges.

[0400] 4 to 7, it is preferable that one end of the insulating layer 127 overlaps the upper surface of the pixel electrode 111a and the other end of the insulating layer 127 overlaps the upper surface of the pixel electrode 111b. This structure allows the ends of the insulating layer 127 to be formed on the generally flat regions of the first layer 113a and the second layer 113b. This makes it relatively easy to form the tapered shapes of the insulating layer 127, the insulating layer 125, and the mask layer 118. Furthermore, peeling of the pixel electrodes 111a, 111b, the first layer 113a, and the second layer 113b can be suppressed. On the other hand, the smaller the overlapping portion between the upper surface of the pixel electrode and the insulating layer 127, the wider the light-emitting region of the light-emitting device, which increases the aperture ratio, which is preferable.

[0401] Note that the insulating layer 127 does not have to overlap the top surfaces of the pixel electrodes. As shown in FIG. 8A , the insulating layer 127 may not overlap the top surfaces of the pixel electrodes, but one end of the insulating layer 127 may overlap a side surface of the pixel electrode 111a, and the other end of the insulating layer 127 may overlap a side surface of the pixel electrode 111b. Also, as shown in FIG. 8B , the insulating layer 127 may not overlap the pixel electrodes, but may be provided in a region sandwiched between the pixel electrodes 111a and 111b. In FIGS. 8A and 8B , part or all of the top surfaces of the inclined and flat portions (regions 103) of the first layer 113a and the second layer 113b located outside the top surfaces of the pixel electrodes are covered by the mask layer 118, the insulating layer 125, and the insulating layer 127. Even with this configuration, the unevenness of the surface on which the common layer 114 and the common electrode 115 are formed can be reduced, and the coverage of the common layer 114 and the common electrode 115 can be improved, compared to a configuration in which the mask layer 118, the insulating layer 125, and the insulating layer 127 are not provided.

[0402] As described above, in each of the configurations shown in FIGS. 4 to 8 , the insulating layer 127, the insulating layer 125, the mask layer 118a, and the mask layer 118b are provided, thereby enabling the common layer 114 and the common electrode 115 to be formed with high coverage from the substantially flat region of the first layer 113a to the substantially flat region of the second layer 113b. This prevents the formation of disconnected portions and locally thin portions in the common layer 114 and the common electrode 115. This prevents poor connection between the light-emitting devices in the common layer 114 and the common electrode 115 due to disconnected portions and increased electrical resistance due to locally thin portions. This allows the display device according to one embodiment of the present invention to improve display quality.

[0403] It is preferable that the light-emitting devices 130a, 130b, and 130c have a protective layer 131. The reliability of the light-emitting devices can be improved by providing the protective layer 131. The protective layer 131 may have a single-layer structure or a stacked structure of two or more layers.

[0404] There is no restriction on the conductivity of the protective layer 131. The protective layer 131 can be made of at least one of an insulating film, a semiconductor film, and a conductive film.

[0405] The protective layer 131 has an inorganic film, which can prevent oxidation of the common electrode 115, prevent impurities (moisture, oxygen, etc.) from entering the light-emitting device, and so on, thereby suppressing deterioration of the light-emitting device and improving the reliability of the display device.

[0406] For the protective layer 131, for example, an inorganic insulating film such as an insulating oxide film, an insulating nitride film, an insulating oxynitride film, or an insulating nitride oxide film can be used. Specific examples of these inorganic insulating films are as given in the description of the insulating layer 125. In particular, the protective layer 131 preferably has an insulating nitride film or an insulating nitride oxide film, and more preferably has an insulating nitride film.

[0407] Alternatively, an inorganic film containing In—Sn oxide (also referred to as ITO), In—Zn oxide, Ga—Zn oxide, Al—Zn oxide, indium gallium zinc oxide (In—Ga—Zn oxide, also referred to as IGZO), or the like can be used for the protective layer 131. The inorganic film preferably has high resistance, specifically, preferably has higher resistance than the common electrode 115. The inorganic film may further contain nitrogen.

[0408] When light emitted from the light-emitting device is extracted through the protective layer 131, it is preferable that the protective layer 131 has high transparency to visible light. For example, ITO, IGZO, and aluminum oxide are preferable because they are inorganic materials that have high transparency to visible light.

[0409] For example, a stacked structure of an aluminum oxide film and a silicon nitride film on the aluminum oxide film, or a stacked structure of an aluminum oxide film and an IGZO film on the aluminum oxide film can be used as the protective layer 131. By using such a stacked structure, impurities (water, oxygen, etc.) can be prevented from entering the EL layer side.

[0410] Furthermore, the protective layer 131 may have an organic film. For example, the protective layer 131 may have both an organic film and an inorganic film. Examples of organic materials that can be used for the protective layer 131 include the organic insulating materials that can be used for the insulating layer 127.

[0411] The protective layer 131 may have a two-layer structure formed by using different film formation methods. Specifically, the first layer of the protective layer 131 may be formed by the ALD method, and the second layer of the protective layer 131 may be formed by the sputtering method.

[0412] A light-shielding layer may be provided on the surface of the substrate 120 facing the resin layer 122. Various optical members may be disposed on the outside of the substrate 120. Examples of optical members include a polarizing plate, a retardation plate, a light diffusion layer (such as a diffusion film), an anti-reflection layer, and a light-collecting film. Furthermore, a surface protection layer such as an anti-static film that suppresses the adhesion of dust, a water-repellent film that makes it difficult for dirt to adhere, a hard coat film that suppresses the occurrence of scratches during use, or an impact absorbing layer may be disposed on the outside of the substrate 120. For example, a glass layer or a silica layer (SiO ｘ The surface protection layer can be preferably formed of a material such as DLC (diamond-like carbon), aluminum oxide (AlO ｘ ), polyester-based materials, or polycarbonate-based materials may also be used. Note that it is preferable to use a material with high transmittance to visible light for the surface protection layer. It is also preferable to use a material with high hardness for the surface protection layer.

[0413] The substrate 120 can be made of glass, quartz, ceramics, sapphire, resin, metal, alloy, semiconductor, or the like. A material that transmits light is used for the substrate on the side from which light from the light-emitting device is extracted. Using a flexible material for the substrate 120 can increase the flexibility of the display device and realize a flexible display. A polarizing plate may also be used as the substrate 120.

[0414] The substrate 120 can be made of polyester resin such as polyethylene terephthalate (PET) or 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, polyamideimide resin, polyurethane resin, polyvinyl chloride resin, polyvinylidene chloride resin, polypropylene resin, polytetrafluoroethylene (PTFE) resin, ABS resin, cellulose nanofiber, etc. The substrate 120 can also be made of glass having a thickness sufficient to provide flexibility.

[0415] When a circularly polarizing plate is superimposed on a display device, it is preferable that the display device has a substrate with high optical isotropy. A substrate with high optical isotropy has small birefringence (or a small amount of birefringence).

[0416] The absolute value of the retardation (phase difference) of a substrate having high optical isotropy is preferably 30 nm or less, more preferably 20 nm or less, and even more preferably 10 nm or less.

[0417] Examples of films with high optical isotropy include triacetyl cellulose (TAC, also known as cellulose triacetate) films, cycloolefin polymer (COP) films, cycloolefin copolymer (COC) films, and acrylic resin films.

[0418] Furthermore, when a film is used as a substrate, the film may absorb water, causing deformation such as wrinkles in the display device. 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 preferably 0.1% or less, and even more preferably 0.01% or less.

[0419] The resin layer 122 can be made of various curable adhesives, such as a photo-curable adhesive (e.g., an ultraviolet curable adhesive), a reactive curable adhesive, a thermosetting adhesive, or an anaerobic adhesive. Examples of such adhesives include epoxy resin, acrylic resin, silicone resin, phenolic resin, polyimide resin, imide resin, PVC (polyvinyl chloride) resin, PVB (polyvinyl butyral) resin, and EVA (ethylene vinyl acetate) resin. Materials with low moisture permeability, such as epoxy resin, are particularly preferred. Two-component resins may also be used. Adhesive sheets or the like may also be used.

[0420] Examples of materials that can be used for conductive layers such as the gate, source, and drain of a transistor, as well as various wirings and electrodes that constitute a display device include metals such as aluminum, titanium, chromium, nickel, copper, yttrium, zirconium, molybdenum, silver, tantalum, and tungsten, and alloys containing these metals as their main components. Films containing these materials can be used as a single layer or a stacked layer structure.

[0421] Examples of light-transmitting conductive materials include conductive oxides such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, and zinc oxide containing gallium, or graphene. Alternatively, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, and titanium, or alloy materials containing such metal materials, can be used. Alternatively, nitrides of such metal materials (e.g., titanium nitride) can be used. When using metal materials or alloy materials (or their nitrides), it is preferable to thin them sufficiently to ensure light-transmitting properties. A stacked film of the above materials can also be used as the conductive layer. For example, a stacked film of an alloy of silver and magnesium and indium tin oxide is preferable because it can enhance conductivity. These materials can also be used for conductive layers such as various wirings and electrodes constituting display devices, and conductive layers (conductive layers functioning as pixel electrodes or counter electrodes) in light-emitting devices.

[0422] 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 oxynitride, silicon nitride oxide, silicon nitride, and aluminum oxide.

[0423] Fig. 10A shows a top view of the display device 100, which is different from that shown in Fig. 3A. The pixel 110 shown in Fig. 10A is composed of four types of subpixels: subpixels 110a, 110b, 110c, and 110d.

[0424] The sub-pixels 110a, 110b, 110c, and 110d may each have a light-emitting device that emits light of a different color, such as sub-pixels of four colors R, G, B, and W, sub-pixels of four colors R, G, B, and Y, or sub-pixels of four colors R, G, B, and IR.

[0425] Furthermore, the display device of one embodiment of the present invention may include a light-receiving device in a pixel.

[0426] Of the four sub-pixels included in pixel 110 shown in FIG. 10A, three may be configured to have a light-emitting device, and the remaining one may be configured to have a light-receiving device.

[0427] The light receiving device may be, for example, a pn-type or pin-type photodiode. The light receiving device functions as a photoelectric conversion device (also called a photoelectric conversion element) that detects light incident on the light receiving device and generates electric charges. The amount of electric charges generated by the light receiving device is determined based on the amount of light incident on the light receiving device.

[0428] The light-receiving device can detect one or both of visible light and infrared light. When detecting visible light, it can detect one or more of light such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red. When detecting infrared light, it is preferable because it enables detection of an object even in a dark place.

[0429] In particular, it is preferable to use an organic photodiode having a layer containing an organic compound as the light-receiving device. Organic photodiodes can be easily made thin, lightweight, and large in area, and have a high degree of freedom in shape and design, making them applicable to a variety of display devices.

[0430] In one embodiment of the present invention, an organic EL device is used as the light-emitting device, and an organic photodiode is used as the light-receiving device. The organic EL device and the organic photodiode can be formed on the same substrate. Therefore, the organic photodiode can be built into a display device using the organic EL device.

[0431] The light-receiving device is driven by applying a reverse bias between the pixel electrode and the common electrode, so that it can detect light incident on the light-receiving device, generate electric charges, and extract them as a current.

[0432] The same manufacturing method as for the light-emitting device can be applied to the light-receiving device. The island-shaped active layer (also called a photoelectric conversion layer) of the light-receiving device is formed by depositing a film to become the active layer on the entire surface and then processing it, rather than using a fine metal mask. Therefore, the island-shaped active layer can be formed with a uniform thickness. Furthermore, by providing a mask layer on the active layer, damage to the active layer during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-receiving device.

[0433] The seventh embodiment can be referred to for the configuration and materials of the light receiving device.

[0434] Fig. 10B shows a cross-sectional view taken along dashed line X3-X4 in Fig. 10A. Note that Fig. 3B can be referred to for a cross-sectional view taken along dashed line X1-X2 in Fig. 10A, and Fig. 9A or Fig. 9B can be referred to for a cross-sectional view taken along dashed line Y1-Y2.

[0435] 10B , in the display device 100, an insulating layer is provided on a layer 101 including transistors, a light-emitting device 130 a and a light-receiving device 150 are provided on the insulating layer, a protective layer 131 is provided to cover the light-emitting device and the light-receiving device, and the substrate 120 is bonded by a resin layer 122. In addition, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in the region between the adjacent light-emitting device and light-receiving device.

[0436] FIG. 10B shows an example of light (light Lem) emitted from the light-emitting device 130a toward the substrate 120 side, and light (light Lin) incident on the light-receiving device 150 from the substrate 120 side.

[0437] The configuration of the light-emitting device 130a is as described above.

[0438] The light-receiving device 150 has a pixel electrode 111d on the insulating layer 255c, a fourth layer 113d on the pixel electrode 111d, a common layer 114 on the fourth layer 113d, and a common electrode 115 on the common layer 114. The fourth layer 113d includes at least an active layer.

[0439] The fourth layer 113d is a layer that is provided in the light-receiving device 150 but not in the light-emitting device. On the other hand, the common layer 114 is a continuous layer that is shared by the light-emitting device and the light-receiving device.

[0440] Here, a layer shared by a light-receiving device and a light-emitting device may have different functions in the light-emitting device and in the light-receiving device. In this specification, components may be referred to based on their functions in the light-emitting device. For example, a hole injection layer functions as a hole injection layer in the light-emitting device and as a hole transport layer in the light-receiving device. Similarly, an electron injection layer functions as an electron injection layer in the light-emitting device and as an electron transport layer in the light-receiving device. Furthermore, a layer shared by a light-receiving device and a light-emitting device may have the same function in the light-emitting device and in the light-receiving device. A hole transport layer functions as a hole transport layer in both the light-emitting device and the light-receiving device, and an electron transport layer functions as an electron transport layer in both the light-emitting device and the light-receiving device.

[0441] A mask layer 118a is located between the first layer 113a and the insulating layer 125, and a mask layer 118d is located between the fourth layer 113d and the insulating layer 125. The mask layer 118a is a remaining portion of a mask layer that was provided on the first layer 113a when the first layer 113a was processed. The mask layer 118d is a remaining portion of a mask layer that was provided in contact with the upper surface of the fourth layer 113d, which is a layer including an active layer, when the fourth layer 113d was processed. The mask layers 118a and 118d may be made of the same material or different materials.

[0442] 10A illustrates an example in which the aperture ratio (which can also be referred to as the size, the size of the light-emitting region, or the size of the light-receiving region) of the subpixel 110d is larger than that of the subpixels 110a, 110b, and 110c, but this is not a limitation of one embodiment of the present invention. The aperture ratios of the subpixels 110a, 110b, 110c, and 110d can be determined as appropriate. The aperture ratios of the subpixels 110a, 110b, 110c, and 110d may be different from one another, or two or more of the subpixels may be equal or approximately equal.

[0443] The subpixel 110d may have a higher aperture ratio than at least one of the subpixels 110a, 110b, and 110c. The larger light-receiving area of ​​the subpixel 110d may facilitate detection of an object. For example, depending on the resolution of the display device and the circuit configuration of the subpixels, the aperture ratio of the subpixel 110d may be higher than the aperture ratios of the other subpixels.

[0444] Furthermore, the subpixel 110d may have a lower aperture ratio than at least one of the subpixels 110a, 110b, and 110c. If the light-receiving area of ​​the subpixel 110d is small, the imaging range is narrowed, which makes it possible to suppress blurring in the imaging result and improve the resolution. This is preferable because it enables high-definition or high-resolution imaging.

[0445] In this way, the sub-pixel 110d can have a detection wavelength, resolution, and aperture ratio suited to the application.

[0446] In a display device according to one embodiment of the present invention, an EL layer is provided in an island shape for each light-emitting device, thereby suppressing leakage current between subpixels. This prevents crosstalk due to unintended light emission, resulting in a display device with extremely high contrast. Furthermore, by providing an insulating layer having a tapered edge between adjacent island-shaped EL layers, discontinuities during formation of a common electrode are suppressed, and locally thin portions of the common electrode are prevented from being formed. This prevents connection defects in the common layer and common electrode due to disconnected portions and increases in electrical resistance due to locally thin portions. This enables the display device according to one embodiment of the present invention to achieve both high resolution and high display quality.

[0447] This embodiment mode can be combined with other embodiment modes as appropriate. In addition, in this specification, when a plurality of configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0448] Embodiment 3 In this embodiment, a manufacturing method of a display device according to one embodiment of the present invention will be described with reference to FIGS. 11 to 16. Note that with regard to materials and formation methods of elements, descriptions of parts similar to those described in Embodiment 1 may be omitted.

[0449] 11 to 15 show a cross-sectional view taken along dashed dotted line X1-X2 and a cross-sectional view taken along dashed dotted line Y1-Y2 shown in Fig. 3A side by side. Fig. 16 shows an enlarged view of the end of the insulating layer 127 and its vicinity.

[0450] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting display devices can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, an atomic layer deposition (ALD) method, etc. CVD methods include a plasma enhanced chemical vapor deposition (PECVD) method and a thermal CVD method. One type of thermal CVD method is a metal organic chemical vapor deposition (MOCVD) method.

[0451] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by a wet film formation method such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0452] In particular, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet printing can be used to fabricate light-emitting devices. Vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, and chemical vapor deposition (CVD). In particular, functional layers included in the EL layer (hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, electron injection layer, charge generation layer, etc.) can be formed by vapor deposition (vacuum deposition, etc.), coating methods (dip coating, die coating, bar coating, spin coating, spray coating, etc.), printing methods (inkjet printing, screen (stencil printing), offset (lithographic printing), flexography (relief printing), gravure, microcontact printing, etc.), etc.

[0453] Furthermore, when processing the thin film that constitutes the display device, a photolithography method or the like can be used. Alternatively, the thin film may be processed by a nanoimprint method, a sandblasting method, a lift-off method, or the like. Furthermore, the island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0454] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching or the like, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0455] 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 of these. Other light sources that can be used include ultraviolet light (also called ultraviolet light), KrF laser light, ArF laser light, etc. Exposure can also be performed using immersion exposure technology. Extreme ultraviolet (EUV) light or X-rays can also be used as the light used for exposure. An electron beam can also be used instead of the light used for exposure. Extreme ultraviolet light, X-rays, or an electron beam are preferred because they enable extremely fine processing. When exposure is performed by scanning a beam such as an electron beam, a photomask is not required.

[0456] For etching the thin film, dry etching, wet etching, sandblasting, or the like can be used.

[0457] First, an insulating layer 255a, an insulating layer 255b, and an insulating layer 255c are formed in this order over the layer 101 including the transistor. Then, pixel electrodes 111a, 111b, and 111c and a conductive layer 123 are formed over the insulating layer 255c (FIG. 11A). The pixel electrodes can be formed by, for example, sputtering or vacuum evaporation.

[0458] Next, it is preferable to perform a hydrophobic treatment on the pixel electrode. By performing the hydrophobic treatment on the pixel electrode, the adhesion between the pixel electrode and the film (here, film 113A) to be formed in a later process can be improved, and film peeling can be suppressed. Note that the hydrophobic treatment does not have to be performed.

[0459] The hydrophobic treatment can be performed by, for example, fluorine modification of the pixel electrodes. The fluorine modification can be performed by, for example, treatment with a fluorine-containing gas, heat treatment, plasma treatment in a fluorine-containing gas atmosphere, or the like. As the fluorine-containing gas, for example, fluorine gas can be used, and for example, fluorocarbon gas can be used. As the fluorocarbon gas, for example, carbon tetrafluoride (CF ４ ) Gas, C ４ F ６ Gas, C ２F ６ Gas, C ４ F ８ Gas, C ５ F ８ A low-grade fluorocarbon gas such as SF6 can be used. ６ Gas, NF ３ Gas, CHF ３ Gases such as helium gas, argon gas, or hydrogen gas can be added to these gases as appropriate.

[0460] The surface of the pixel electrode can be hydrophobized by performing a plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a Group 18 element such as argon, followed by a treatment using a silylating agent. Examples of the silylating agent that can be used include hexamethyldisilazane (HMDS) and trimethylsilylimidazole (TMSI). Furthermore, the surface of the pixel electrode can be hydrophobized by performing a plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a Group 18 element such as argon, followed by a treatment using a silane coupling agent.

[0461] By performing plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a Group 18 element such as argon, it is possible to damage the surface of the pixel electrode. This makes it easier for methyl groups contained in a silylating agent such as HMDS to bond to the surface of the pixel electrode. Also, silane coupling by a silane coupling agent is more likely to occur. As described above, by performing plasma treatment on the surface of the pixel electrode in a gas atmosphere containing a Group 18 element such as argon, and then performing treatment using a silylating agent or a silane coupling agent, it is possible to hydrophobize the surface of the pixel electrode.

[0462] Treatment using a silylating agent or a silane coupling agent can be performed by applying the silylating agent or the silane coupling agent using, for example, a spin coating method or a dipping method. Treatment using a silylating agent or a silane coupling agent can also be performed by, for example, using a vapor phase method to form a film containing a silylating agent or a film containing a silane coupling agent on a pixel electrode or the like. In the vapor phase method, first, a material containing a silylating agent or a material containing a silane coupling agent is volatilized to incorporate the silylating agent or the silane coupling agent into an atmosphere. Next, a substrate on which a pixel electrode or the like is formed is placed in this atmosphere. This allows a film containing the silylating agent or the silane coupling agent to be formed on the pixel electrode, thereby hydrophobizing the surface of the pixel electrode.

[0463] Subsequently, a film 113A, which will later become the first layer 113a, is formed on the pixel electrode (FIG. 11A).

[0464] 11A , in the cross-sectional view between the dashed dotted line Y1-Y2, the film 113A is not formed on the conductive layer 123. For example, by using a mask for defining the film formation area (also called an area mask or a rough metal mask to distinguish it from a fine metal mask), the film 113A can be formed only in the desired region. By employing a film formation process using an area mask and a processing process using a resist mask, a light-emitting device can be manufactured through a relatively simple process.

[0465] The film 113A can be formed by, for example, a vapor deposition method, specifically a vacuum deposition method. Alternatively, the film 113A may be formed by a transfer method, a printing method, an inkjet method, a coating method, or the like.

[0466] Subsequently, a mask film 118A that will later become the mask layer 118a and a mask film 119A that will later become the mask layer 119a are formed in this order on the film 113A and the conductive layer 123 (FIG. 11A).

[0467] In this embodiment, an example is shown in which the mask film is formed with a two-layer structure of mask film 118A and mask film 119A, but the mask film may have a single-layer structure or a laminated structure of three or more layers.

[0468] By providing a mask layer over the film 113A, damage to the film 113A during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be improved.

[0469] The mask film 118A is made of a film that is highly resistant to the processing conditions of the film 113A, specifically, a film that has a large etching selectivity with respect to the film 113A. The mask film 119A is made of a film that has a large etching selectivity with respect to the mask film 118A.

[0470] Furthermore, the mask films 118A and 119A are formed at a temperature lower than the heat-resistant temperature of the film 113A. The substrate temperature when forming the mask films 118A and 119A is typically 200°C or lower, preferably 150°C or lower, more preferably 120°C or lower, more preferably 100°C or lower, and even more preferably 80°C or lower.

[0471] Examples of the heat resistance temperature index include a glass transition point, a softening point, a melting point, a thermal decomposition temperature, a 5% weight loss temperature, etc. The heat resistance temperature of the films 113A to 113C (i.e., the first to third layers 113a to 113c) can be any of these temperatures, preferably the lowest temperature among them.

[0472] It is preferable to use a film that can be removed by wet etching for the mask film 118A and the mask film 119A. By using the wet etching method, damage to the film 113A during processing of the mask film 118A and the mask film 119A can be reduced compared to when using the dry etching method.

[0473] The mask films 118A and 119A can be formed by, for example, sputtering, ALD (including thermal ALD and PEALD), CVD, or vacuum deposition. Alternatively, the mask films 118A and 119A may be formed by the wet film formation method described above.

[0474] It is preferable that the mask film 118A formed on and in contact with the film 113A be formed using a formation method that causes less damage to the film 113A than the mask film 119A. For example, it is preferable to form the mask film 118A using the ALD method or the vacuum deposition method rather than the sputtering method.

[0475] The mask film 118A and the mask film 119A may each be made of one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, an inorganic insulating film, or the like.

[0476] The mask films 118A and 119A can each be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. It is particularly preferable to use a low-melting-point material such as aluminum or silver. Using a metal material capable of blocking ultraviolet light for one or both of the mask films 118A and 119A is preferable because it can prevent ultraviolet light from being irradiated onto the film 113A and thereby prevent deterioration of the film 113A.

[0477] Furthermore, for the mask film 118A and the mask film 119A, metal oxides 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 indium tin oxide containing silicon can be used, respectively.

[0478] In addition, instead of the above gallium, an element M (M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used.

[0479] Furthermore, a film containing a material that has light-shielding properties, particularly against ultraviolet light, can be used as the mask film. For example, a film that is reflective to ultraviolet light or a film that absorbs ultraviolet light can be used. As the light-shielding material, various materials can be used, such as metals, insulators, semiconductors, and semimetals that have light-shielding properties against ultraviolet light. However, since part or all of the mask film will be removed in a later process, it is preferable that the mask film be a film that can be processed by etching, and particularly that the processability is good.

[0480] For example, semiconductor materials such as silicon or germanium can be used as materials that are highly compatible with semiconductor manufacturing processes. Alternatively, oxides or nitrides of the above semiconductor materials can be used. Alternatively, non-metallic materials such as carbon, semi-metallic materials, or compounds thereof can be used. Alternatively, metals such as titanium, tantalum, tungsten, chromium, and aluminum, or alloys containing one or more of these, can be used. Alternatively, oxides containing the above metals, such as titanium oxide or chromium oxide, or nitrides such as titanium nitride, chromium nitride, or tantalum nitride can be used.

[0481] By using a film containing a material having a light-blocking property against ultraviolet light as the mask film, it is possible to prevent the EL layer from being irradiated with ultraviolet light during an exposure process, etc. By preventing the EL layer from being damaged by ultraviolet light, the reliability of the light-emitting device can be improved.

[0482] The same effect can be achieved when a film containing a material that blocks ultraviolet light is used as the material for the insulating film 125A described later.

[0483] Furthermore, the mask films 118A and 119A can each be made of various inorganic insulating films that can be used for the protective layer 131. In particular, oxide insulating films are preferable because they have higher adhesion to the film 113A than nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can each be used for the mask films 118A and 119A. For example, aluminum oxide films can be formed as the mask films 118A and 119A using the ALD method. Using the ALD method is preferable because it can reduce damage to the underlying layer (especially the EL layer).

[0484] For example, an inorganic insulating film (e.g., an aluminum oxide film) formed using the ALD method can be used as the mask film 118A, and an inorganic film (e.g., an In-Ga-Zn oxide film, an aluminum film, or a tungsten film) formed using the sputtering method can be used as the mask film 119A.

[0485] The same inorganic insulating film can be used for both the mask film 118A and the insulating layer 125 to be formed later. For example, an aluminum oxide film formed using an ALD method can be used for both the mask film 118A and the insulating layer 125. The mask film 118A and the insulating layer 125 may be formed under the same or different film-forming conditions. For example, by forming the mask film 118A under the same conditions as the insulating layer 125, the mask film 118A can be an insulating layer with high barrier properties against at least one of water and oxygen. On the other hand, since the mask film 118A is a layer that will be largely or completely removed in a later process, it is preferable that it be easily processed. Therefore, it is preferable that the mask film 118A be formed under conditions where the substrate temperature during film formation is lower than that of the insulating layer 125.

[0486] An organic material may be used for one or both of the mask films 118A and 119A. For example, a material that can be dissolved in a chemically stable solvent may be used as the organic material for at least the uppermost film of the film 113A. In particular, a material that dissolves in water or alcohol is preferably used. When forming a film of such a material, it is preferable to apply the material dissolved in a solvent such as water or alcohol by a wet film formation method, and then perform a heat treatment to evaporate the solvent. In this case, performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the film 113A.

[0487] The mask film 118A and the mask film 119A may each be made of an organic resin such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, alcohol-soluble polyamide resin, or a fluororesin such as a perfluoropolymer.

[0488] For example, the mask film 118A can be an organic film (e.g., a PVA film) formed using either a vapor deposition method or the above-mentioned wet film formation method, and the mask film 119A can be an inorganic film (e.g., a silicon nitride film) formed using a sputtering method.

[0489] As described in Embodiment 1, in the display device of one embodiment of the present invention, part of the mask film may remain as a mask layer.

[0490] Subsequently, a resist mask 190a is formed on the mask film 119A (FIG. 11A). The resist mask 190a can be formed by applying a photosensitive resin (photoresist) and then performing exposure and development.

[0491] The resist mask 190a may be made of either a positive resist material or a negative resist material.

[0492] The resist mask 190a is provided in a position overlapping with the pixel electrode 111a. The resist mask 190a is preferably provided also in a position overlapping with the conductive layer 123. This can prevent the conductive layer 123 from being damaged during the manufacturing process of the display device. Note that the resist mask 190a does not necessarily have to be provided on the conductive layer 123.

[0493] 11A , the resist mask 190a is preferably provided so as to cover the area from the end of the first layer 113a to the end of the conductive layer 123 (the end on the first layer 113a side). This allows the ends of the mask layers 118a and 119a to overlap with the end of the first layer 113a even after the mask films 118A and 119A are processed. Furthermore, because the mask layers 118a and 119a are provided so as to cover the area from the end of the first layer 113a to the end of the conductive layer 123 (the end on the first layer 113a side), exposure of the insulating layer 255c can be suppressed (see the cross-sectional view between Y1 and Y2 in FIG. 11C ). This prevents the insulating layers 255a to 255c and parts of the insulating layers included in the layer 101 including the transistor from being removed by etching or the like, thereby preventing the conductive layers included in the layer 101 including the transistor from being exposed. Therefore, it is possible to prevent the conductive layer from being unintentionally electrically connected to another conductive layer, and for example, it is possible to prevent a short circuit between the conductive layer and the common electrode 115.

[0494] Next, a resist mask 190a is used to remove a portion of the mask film 119A, thereby forming a mask layer 119a (FIG. 11B). The mask layer 119a remains on the pixel electrode 111a and on the conductive layer 123. Then, the resist mask 190a is removed. Next, using the mask layer 119a as a mask (also referred to as a hard mask), a portion of the mask film 118A is removed, thereby forming a mask layer 118a (FIG. 11C).

[0495] The mask films 118A and 119A can be processed by wet etching or dry etching, respectively, and are preferably processed by anisotropic etching.

[0496] Compared to the case of using dry etching, the use of wet etching can reduce damage to the film 113A during processing of the mask films 118A and 119A. When using wet etching, it is preferable to use a chemical solution such as a developer, a tetramethylammonium hydroxide (TMAH) aqueous solution, dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0497] In processing the mask film 119A, since the film 113A is not exposed, the range of processing methods to be selected is wider than in processing the mask film 118A. Specifically, even when a gas containing oxygen is used as an etching gas in processing the mask film 119A, deterioration of the film 113A can be further suppressed.

[0498] Furthermore, when dry etching is used to process the mask film 118A, deterioration of the film 113A can be suppressed by not using a gas containing oxygen as the etching gas. ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ It is preferable to use a gas containing a noble gas (also called a rare gas) such as He as the etching gas.

[0499] For example, when an aluminum oxide film formed by the ALD method is used as the mask film 118A, CHF ３ and He or CHF ３ and He and CH ４ The mask film 118A can be processed by dry etching using a diluted phosphoric acid solution. When an In-Ga-Zn oxide film formed by sputtering is used as the mask film 119A, the mask film 119A can be processed by wet etching using a diluted phosphoric acid solution. ４The mask film 119A may be processed by dry etching using diluted phosphoric acid and Ar. Alternatively, the mask film 119A may be processed by wet etching using diluted phosphoric acid. When a tungsten film formed by sputtering is used as the mask film 119A, SF ６ , C.F. ４ and O ２ , or CF ４ and Cl ２ and O ２ The mask film 119A can be processed by dry etching using the above.

[0500] The resist mask 190a can be removed by, for example, ashing using oxygen plasma. Alternatively, ashing using oxygen gas and CF ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ Alternatively, a noble gas such as He may be used. Alternatively, the resist mask 190a may be removed by wet etching. At this time, the mask film 118A is located on the outermost surface and the film 113A is not exposed, so that damage to the film 113A can be suppressed in the process of removing the resist mask 190a. This also broadens the range of options for removing the resist mask 190a.

[0501] Subsequently, the film 113A is processed to form the first layer 113a. For example, the mask layer 119a and the mask layer 118a are used as hard masks to remove a portion of the film 113A, thereby forming the first layer 113a (FIG. 11C).

[0502] 11C, a laminated structure of the first layer 113a, the mask layer 118a, and the mask layer 119a remains on the pixel electrode 111a, and the pixel electrodes 111b and 111c are exposed.

[0503] 11C shows an example in which the edge of the first layer 113a is positioned outside the edge of the pixel electrode 111a. This configuration can increase the aperture ratio of the pixel. Although not shown in FIG. 11C, the etching process may form a recess in a region of the insulating layer 255c that does not overlap with the first layer 113a.

[0504] Furthermore, because the first layer 113a covers the top and side surfaces of the pixel electrode 111a, subsequent processes can be performed without exposing the pixel electrode 111a. If the edges of the pixel electrode 111a are exposed, corrosion may occur during etching processes, etc. Products resulting from corrosion of the pixel electrode 111a may be unstable, dissolving in solution during wet etching, or scattering into the atmosphere during dry etching. Dissolving the products into solution or scattering into the atmosphere may result in the products adhering to, for example, the processed surface and the side surfaces of the first layer 113a, potentially adversely affecting the characteristics of the light-emitting device or forming leak paths between multiple light-emitting devices. Furthermore, in regions where the edges of the pixel electrode 111a are exposed, the adhesion between adjacent layers may be reduced, potentially making the first layer 113a or the pixel electrode 111a more susceptible to peeling.

[0505] Therefore, by configuring the first layer 113a to cover the upper and side surfaces of the pixel electrode 111a, it is possible to improve, for example, the yield and characteristics of the light-emitting device.

[0506] In the region corresponding to the connection portion 140, the laminated structure of the mask layer 118a and the mask layer 119a remains on the conductive layer 123.

[0507] 11C , the mask layers 118a and 119a are provided to cover the ends of the first layer 113a and the conductive layer 123, and the insulating layer 255c is not exposed. Therefore, the insulating layers 255a to 255c and parts of the insulating layers included in the layer 101 including the transistors are removed by etching or the like, which can prevent the conductive layers included in the layer 101 including the transistors from being exposed. Therefore, the conductive layers can be prevented from being unintentionally electrically connected to other conductive layers.

[0508] The film 113A is preferably processed by anisotropic etching, particularly anisotropic dry etching, or wet etching.

[0509] When dry etching is used, deterioration of the film 113A can be suppressed by not using a gas containing oxygen as the etching gas.

[0510] Alternatively, a gas containing oxygen may be used as the etching gas. When the etching gas contains oxygen, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently high etching rate. This can suppress damage to the film 113A. Furthermore, problems such as adhesion of reaction products that occur during etching can be suppressed.

[0511] When dry etching is used, for example, H ２ , C.F. ４ , C ４ F ８ , S.F. ６ , CHF ３ , Cl ２ , H ２ O, BCl ３ It is preferable to use a gas containing one or more of the noble gases such as He and Ar as the etching gas. Alternatively, it is preferable to use a gas containing one or more of these and oxygen as the etching gas. Alternatively, oxygen gas may be used as the etching gas. Specifically, for example, H ２ and a gas containing Ar, or CF ４A gas containing CF and He can be used as an etching gas. ４ A gas containing H, He, and oxygen can be used as the etching gas. ２ A gas containing Ar and a gas containing oxygen can be used as the etching gas.

[0512] As described above, in one embodiment of the present invention, the resist mask 190a is formed over the mask film 119A, and part of the mask film 119A is removed using the resist mask 190a to form the mask layer 119a. Then, part of the film 113A is removed using the mask layer 119a as a hard mask to form the first layer 113a. Therefore, it can be said that the first layer 113a is formed by processing the film 113A by photolithography. Note that part of the film 113A may be removed using the resist mask 190a. Then, the resist mask 190a may be removed.

[0513] Next, it is preferable to perform a hydrophobic treatment on the pixel electrode. When processing the film 113A, the surface state of the pixel electrode may change to a hydrophilic state. By performing a hydrophobic treatment on the pixel electrode, it is possible to improve the adhesion between the pixel electrode and a film (here, film 113B) to be formed in a later process, and to suppress film peeling. Note that the hydrophobic treatment is not necessarily required.

[0514] Subsequently, a film 113B, which will later become the second layer 113b, is formed on the pixel electrodes 111b and 111c and on the mask layer 119a (FIG. 12A).

[0515] Film 113B can be formed using methods similar to those that can be used to form film 113A.

[0516] Next, a mask film 118B, which will later become mask layer 118b, and a mask film 119B, which will later become mask layer 119b, are formed in this order on film 113B, and then a resist mask 190b is formed (FIG. 12A). The materials and formation methods for mask films 118B and 119B are the same as those applicable to mask films 118A and 119A. The materials and formation methods for resist mask 190b are the same as those applicable to resist mask 190a.

[0517] The resist mask 190b is provided at a position overlapping the pixel electrode 111b.

[0518] Next, a resist mask 190b is used to remove a portion of the mask film 119B, forming a mask layer 119b. The mask layer 119b remains on the pixel electrode 111b. Then, the resist mask 190b is removed. Next, using the mask layer 119b as a mask, a portion of the mask film 118B is removed, forming a mask layer 118b. Next, the film 113B is processed to form the second layer 113b. For example, using the mask layer 119b and the mask layer 118b as a hard mask, a portion of the film 113B is removed, forming the second layer 113b ( FIG. 12B ).

[0519] 12B, a laminated structure of the second layer 113b, the mask layer 118b, and the mask layer 119b remains on the pixel electrode 111b, and the mask layer 119a and the pixel electrode 111c are exposed.

[0520] Next, it is preferable to perform a hydrophobic treatment on the pixel electrode. When processing the film 113B, the surface state of the pixel electrode may change to a hydrophilic state. By performing a hydrophobic treatment on the pixel electrode, it is possible to improve the adhesion between the pixel electrode and a film (here, film 113C) to be formed in a later process, and to suppress film peeling. Note that the hydrophobic treatment is not necessarily required.

[0521] Subsequently, a film 113C that will later become the third layer 113c is formed on the pixel electrode 111c and the mask layers 119a and 119b (FIG. 12B).

[0522] Film 113C can be formed using methods similar to those that can be used to form film 113A.

[0523] Next, a mask film 118C, which will later become the mask layer 118c, and a mask film 119C, which will later become the mask layer 119c, are formed in this order on the film 113C, and then a resist mask 190c is formed (FIG. 12B). The materials and formation methods of the mask films 118C and 119C are the same as those applicable to the mask films 118A and 119A. The materials and formation methods of the resist mask 190c are the same as those applicable to the resist mask 190a.

[0524] The resist mask 190c is provided at a position overlapping the pixel electrode 111c.

[0525] Next, a resist mask 190c is used to remove a portion of the mask film 119C, forming a mask layer 119c. The mask layer 119c remains on the pixel electrode 111c. The resist mask 190c is then removed. Next, using the mask layer 119c as a mask, a portion of the mask film 118C is removed, forming a mask layer 118c. Next, the film 113C is processed to form a third layer 113c. For example, using the mask layer 119c and the mask layer 118c as a hard mask, a portion of the film 113C is removed, forming the third layer 113c (FIG. 12C).

[0526] 12C, a laminated structure of the third layer 113c, the mask layer 118c, and the mask layer 119c remains on the pixel electrode 111c, and the mask layers 119a and 119b are exposed.

[0527] Note that the side surfaces of the first layer 113 a, the second layer 113 b, and the third layer 113 c are preferably perpendicular or substantially perpendicular to the surface on which they are to be formed. For example, the angle formed between the surface on which they are to be formed and the side surfaces is preferably 60° to 90°.

[0528] As described above, the distance between any two adjacent layers of the first layer 113a, the second layer 113b, and the third layer 113c formed by photolithography can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, the distance can be defined, for example, as the distance between any two adjacent opposing ends of the first layer 113a, the second layer 113b, and the third layer 113c. By narrowing the distance between the island-shaped EL layers in this manner, a display device with high definition and a large aperture ratio can be provided.

[0529] 10A and 10B, when a display device having both a light-emitting device and a light-receiving device is fabricated, the fourth layer 113d of the light-receiving device is formed in the same order as the first to third layers 113a to 113c. The order of forming the first to fourth layers 113a to 113d is not particularly limited. For example, by forming a layer with high adhesion to the pixel electrode first, film peeling during the process can be suppressed. For example, if the first to third layers 113a to 113c have higher adhesion to the pixel electrode than the fourth layer 113d, it is preferable to form the first to third layers 113a to 113c first. Furthermore, the thickness of the layer formed first may affect the distance between the substrate and a mask for defining the film formation area in the subsequent layer formation process. By forming the thinner layer first, shadowing (the formation of a layer in a shadow area) can be suppressed. For example, when forming a light-emitting device with a tandem structure, the first to third layers 113a to 113c are often thicker than the fourth layer 113d, so it is preferable to form the fourth layer 113d first. Furthermore, when a film is formed by a wet process using a polymer material, it is preferable to form the film first. For example, when a polymer material is used for the active layer, it is preferable to form the fourth layer 113d first. As described above, by determining the order of formation depending on the material, film formation method, etc., it is possible to increase the yield in manufacturing display devices.

[0530] Next, it is preferable to remove the mask layers 119a, 119b, and 119c ( FIG. 13A ). Depending on the subsequent process, the mask layers 118a, 118b, 118c, 119a, 119b, and 119c may remain on the display device. By removing the mask layers 119a, 119b, and 119c at this stage, it is possible to prevent the mask layers 119a, 119b, and 119c from remaining on the display device. For example, if a conductive material is used for the mask layers 119a, 119b, and 119c, removing the mask layers 119a, 119b, and 119c in advance can prevent the generation of leakage current and the formation of capacitance due to the remaining mask layers 119a, 119b, and 119c.

[0531] Although the present embodiment will be described taking as an example the case where the mask layers 119 a, 119 b, and 119 c are removed, the mask layers 119 a, 119 b, and 119 c do not necessarily have to be removed. For example, if the mask layers 119 a, 119 b, and 119 c contain the aforementioned material that blocks ultraviolet light, it is preferable to proceed to the next step without removing the mask layers, since this protects the EL layer from ultraviolet light.

[0532] The mask layer removal step can be performed using the same method as the mask layer processing step. In particular, by using a wet etching method, damage to the first layer 113 a, the second layer 113 b, and the third layer 113 c during mask layer removal can be reduced compared to when a dry etching method is used.

[0533] The mask layer may also be removed by dissolving it in a solvent such as water or alcohol, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0534] After removing the mask layers, drying treatment may be performed to remove water contained in the first layer 113a, the second layer 113b, and the third layer 113c and water adsorbed on the surfaces of the first layer 113a, the second layer 113b, and the third layer 113c. For example, heat treatment can be performed in an inert gas atmosphere or a reduced-pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. A reduced-pressure atmosphere is preferable because drying can be performed at a lower temperature.

[0535] Next, an insulating film 125A that will later become the insulating layer 125 is formed so as to cover the pixel electrode, the first layer 113a, the second layer 113b, the third layer 113c, the mask layer 118a, the mask layer 118b, and the mask layer 118c (FIG. 13A). Next, an insulating film 127a is formed on the insulating film 125A (FIG. 13B).

[0536] The insulating films 125A and 127a are preferably formed by a method that causes less damage to the first layer 113a, the second layer 113b, and the third layer 113c. In particular, since the insulating film 125A is formed in contact with the side surfaces of the first layer 113a, the second layer 113b, and the third layer 113c, it is preferably formed by a method that causes less damage to the first layer 113a, the second layer 113b, and the third layer 113c than the insulating film 127a.

[0537] The insulating films 125A and 127a are formed at a temperature lower than the heat-resistant temperatures of the first layer 113a, the second layer 113b, and the third layer 113c, respectively. By increasing the substrate temperature during film formation, the insulating film 125A can have a low impurity concentration and a high barrier property against at least one of water and oxygen, even if it is thin.

[0538] The substrate temperature when forming the insulating film 125A and the insulating film 127a is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0539] As the insulating film 125A, it is preferable to form an insulating film having a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above substrate temperature range.

[0540] The insulating film 125A is preferably formed by, for example, an ALD method. The ALD method is preferable because it can reduce film formation damage and form a film with high coverage. The insulating film 125A is preferably formed as an aluminum oxide film by, for example, an ALD method.

[0541] Alternatively, the insulating film 125A may be formed by a sputtering method, a CVD method, or a PECVD method, which have a faster film formation rate than an ALD method. This enables a highly reliable display device to be manufactured with high productivity.

[0542] The insulating film 127a is preferably formed by the wet deposition method described above. For example, the insulating film 127a is preferably formed using a photosensitive resin by spin coating, more specifically, a photosensitive acrylic resin.

[0543] Furthermore, heat treatment (also referred to as pre-baking) is preferably performed after the insulating film 127a is formed. The heat treatment is performed at a temperature lower than the upper temperature limits of the first layer 113a, the second layer 113b, and the third layer 113c. The substrate temperature during the heat treatment is preferably 50° C. or higher and 200° C. or lower, more preferably 60° C. or higher and 150° C. or lower, and even more preferably 70° C. or higher and 120° C. or lower. This allows the solvent contained in the insulating film 127a to be removed.

[0544] Next, as shown in FIG. 13C , exposure is performed to expose a portion of the insulating film 127a to visible light or ultraviolet light. Here, if a positive acrylic resin is used for the insulating film 127a, visible light or ultraviolet light is irradiated using a mask on regions where the insulating layer 127 will not be formed in a later process. The insulating layer 127 is formed in a region sandwiched between any two of the pixel electrodes 111a, 111b, and 111c, and around the conductive layer 123. Therefore, as shown in FIG. 13C , visible light or ultraviolet light is irradiated using a mask on the pixel electrodes 111a, 111b, and 111c, and on the conductive layer 123.

[0545] The width of the insulating layer 127 to be formed later can be controlled by the region to be exposed to light. In this embodiment, the insulating layer 127 is processed so as to have a portion overlapping with the upper surface of the pixel electrode (FIGS. 4A and 4B). As shown in FIG. 8A or 8B, the insulating layer 127 does not necessarily have a portion overlapping with the upper surface of the pixel electrode.

[0546] The light used for exposure preferably contains i-line (wavelength 365 nm), and may contain at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0547] 13C shows an example in which a positive photosensitive resin is used for the insulating film 127a and visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 is not formed, but the present invention is not limited to this. For example, a negative photosensitive resin may be used for the insulating film 127a. In this case, visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 is formed.

[0548] 14A and 16A, development is performed to remove the exposed regions of the insulating film 127a, forming an insulating layer 127b. Note that FIG. 16A is an enlarged view of the second layer 113b and the end portion and vicinity of the insulating layer 127b shown in FIG. 14A. The insulating layer 127b is formed in a region sandwiched between any two of the pixel electrodes 111a, 111b, and 111c, and around the conductive layer 123. Here, when an acrylic resin is used for the insulating film 127a, it is preferable to use an alkaline solution as the developer, such as a tetramethylammonium hydroxide (TMAH) aqueous solution.

[0549] Subsequently, residues (so-called scum) remaining after development may be removed, for example, by ashing using oxygen plasma.

[0550] Note that etching may be performed to adjust the height of the surface of the insulating layer 127b. The insulating layer 127b may be processed by ashing using oxygen plasma, for example. Even when a non-photosensitive material is used as the insulating film 127a, the height of the surface of the insulating film 127a can be adjusted by ashing or the like.

[0551] Subsequently, the entire substrate may be exposed to visible light or ultraviolet light, and the insulating layer 127b may be irradiated with the energy density of the exposure. ２ Larger than 800 mJ / cm ２ It is preferable that the dose is 0 mJ / cm or less. ２ Greater than 500 mJ / cm ２ It is more preferable to perform the following. By performing such exposure after development, the transparency of the insulating layer 127b can be improved in some cases. Furthermore, the substrate temperature required for heat treatment to transform the insulating layer 127b into a tapered shape in a later step can be reduced in some cases.

[0552] On the other hand, as will be described later, not exposing the insulating layer 127b to light may make it easier to change the shape of the insulating layer 127b or to deform the insulating layer 127 into a tapered shape in a later step. Therefore, it may be preferable not to expose the insulating layer 127b or 127 after development.

[0553] For example, if a photocurable resin is used as the material for the insulating layer 127b, exposing the insulating layer 127b to light initiates polymerization, thereby hardening the insulating layer 127b. At this stage, the insulating layer 127b may not be exposed to light, and at least one of a first etching process, a post-bake, and a second etching process, which will be described later, may be performed while the insulating layer 127b remains in a state in which it is relatively susceptible to shape deformation. This prevents the occurrence of irregularities on the surfaces on which the common layer 114 and the common electrode 115 are formed, and also prevents the common layer 114 and the common electrode 115 from being broken. The insulating layer 127b (or the insulating layer 127) may be exposed to light after any of the first etching process, post-bake, and second etching processes, which will be described later.

[0554] Next, as shown in FIGS. 14B and 16B, an etching process is performed using the insulating layer 127b as a mask to remove a portion of the insulating film 125A and thin the film thickness of portions of the mask layers 118a, 118b, and 118c. This results in the formation of the insulating layer 125 below the insulating layer 127b. Furthermore, the surfaces of the thin portions of the mask layers 118a, 118b, and 118c are exposed. Note that FIG. 16B is an enlarged view of the second layer 113b and the end and vicinity of the insulating layer 127b shown in FIG. 14B. Note that hereinafter, the etching process using the insulating layer 127b as a mask may be referred to as the first etching process.

[0555] The first etching treatment can be performed by dry etching or wet etching. Note that it is preferable to form the insulating film 125A using the same material as the mask layers 118a, 118b, and 118c, because the first etching treatment can be performed simultaneously.

[0556] As shown in FIG. 16B, by performing etching using insulating layer 127b, which has tapered side surfaces, as a mask, the side surfaces of insulating layer 125 and the upper end portions of the side surfaces of mask layers 118a, 118b, and 118c can be tapered relatively easily.

[0557] When dry etching is performed, it is preferable to use a chlorine-based gas. ２ , BCl ３ , SiCl ４ , and CCl ４ These gases can be used alone or in combination of two or more. Furthermore, the chlorine-based gas can be appropriately mixed with one or more of oxygen gas, hydrogen gas, helium gas, and argon gas. By using dry etching, thin regions of the mask layers 118 a, 118 b, and 118 c can be formed with good in-plane uniformity.

[0558] The dry etching apparatus may be a dry etching apparatus having a high-density plasma source. Examples of the dry etching apparatus having a high-density plasma source include an inductively coupled plasma (ICP) etching apparatus. Alternatively, a capacitively coupled plasma (CCP) etching apparatus having parallel-plate electrodes may be used. The capacitively coupled plasma etching apparatus having parallel-plate electrodes may be configured to apply a high-frequency voltage to one of the parallel-plate electrodes. Alternatively, it may be configured to apply multiple different high-frequency voltages to one of the parallel-plate electrodes. Alternatively, it may be configured to apply a high-frequency voltage of the same frequency to each of the parallel-plate electrodes. Alternatively, it may be configured to apply high-frequency voltages of different frequencies to each of the parallel-plate electrodes.

[0559] Furthermore, when dry etching is performed, by-products generated by the dry etching may be deposited on the upper surface and side surfaces of insulating layer 127b, etc. Therefore, components contained in the etching gas, components contained in insulating film 125A, and components contained in mask layers 118a, 118b, and 118c may be contained in insulating layer 127 after the display device is completed.

[0560] Furthermore, the first etching treatment is preferably performed by wet etching. By using a wet etching method, damage to the first layer 113a, the second layer 113b, and the third layer 113c can be reduced compared to when a dry etching method is used. For example, the wet etching can be performed using an alkaline solution. For example, an aqueous solution of tetramethylammonium hydroxide (TMAH), which is an alkaline solution, is preferably used for wet etching of an aluminum oxide film. In this case, the wet etching can be performed by a paddle method. Note that if the insulating film 125A is formed using the same material as the mask layers 118a, 118b, and 118c, the above etching treatment can be performed simultaneously, which is preferable.

[0561] 14B and 16B , in the first etching process, the mask layers 118 a, 118 b, and 118 c are not completely removed, and the etching process is stopped when the film thickness is reduced. In this way, by leaving the corresponding mask layers 118 a, 118 b, and 118 c on the first layer 113 a, second layer 113 b, and third layer 113 c, it is possible to prevent the first layer 113 a, second layer 113 b, and third layer 113 c from being damaged in subsequent processing steps.

[0562] 14B and 16B illustrate a configuration in which the thicknesses of the mask layers 118a, 118b, and 118c are thinned, but the present invention is not limited thereto. For example, depending on the thicknesses of the insulating film 125A and the mask layers 118a, 118b, and 118c, the first etching process may be stopped before the insulating film 125A is processed into the insulating layer 125. Specifically, the first etching process may be stopped after only partially thinning the insulating film 125A. Furthermore, if the insulating film 125A is formed using the same material as the mask layers 118a, 118b, and 118c, the boundary between the insulating film 125A and the mask layers 118a, 118b, and 118c may become unclear, making it impossible to determine whether the insulating layer 125 has been formed or whether the thicknesses of the mask layers 118a, 118b, and 118c have been thinned.

[0563] 14B and 16B show an example in which the shape of the insulating layer 127b is unchanged from that of FIGS. 14A and 16A, but the present invention is not limited to this. For example, the end of the insulating layer 127b may droop and cover the end of the insulating layer 125. Also, for example, the end of the insulating layer 127b may contact the upper surfaces of the mask layers 118a, 118b, and 118c. As described above, if the developed insulating layer 127b is not exposed to light, the shape of the insulating layer 127b may be easily changed.

[0564] Next, heat treatment (also referred to as post-baking) is performed. As shown in FIGS. 15A and 16C, heat treatment can transform the insulating layer 127b into the insulating layer 127 having tapered side surfaces. As described above, the shape of the insulating layer 127b may already change and have tapered side surfaces when the first etching treatment is completed. The heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., and more preferably 70° C. to 130° C. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced-pressure atmosphere. A reduced-pressure atmosphere is preferable because drying can be performed at a lower temperature. The substrate temperature in this heat treatment is preferably higher than that in the heat treatment (pre-baking) performed after the formation of the insulating film 127a. This improves the adhesion between insulating layer 127 and insulating layer 125, and also improves the corrosion resistance of insulating layer 127. Fig. 16C is an enlarged view of second layer 113b and the end of insulating layer 127 and its vicinity shown in Fig. 15A.

[0565] By not completely removing the mask layers 118a, 118b, and 118c in the first etching process and leaving the mask layers 118a, 118b, and 118c in a thinner state, the first layer 113a, the second layer 113b, and the third layer 113c can be prevented from being damaged and deteriorated in the heat treatment, thereby improving the reliability of the light-emitting device.

[0566] 6A and 6B, depending on the material of the insulating layer 127 and the temperature, time, and atmosphere of the post-baking, a concave curved shape may be formed on the side surface of the insulating layer 127. For example, the higher the temperature or the longer the post-baking time, the more likely the shape of the insulating layer 127 is to change, and a concave curved shape may be formed. Furthermore, as described above, if the developed insulating layer 127b is not exposed to light, the shape of the insulating layer 127 may be more likely to change during post-baking.

[0567] Next, as shown in FIGS. 15B and 16D , an etching process is performed using the insulating layer 127 as a mask to remove portions of the mask layers 118a, 118b, and 118c. Note that a portion of the insulating layer 125 may also be removed. As a result, openings are formed in the mask layers 118a, 118b, and 118c, respectively, exposing the top surfaces of the first layer 113a, the second layer 113b, the third layer 113c, and the conductive layer 123. Note that FIG. 16D is an enlarged view of the second layer 113b and the end of the insulating layer 127 and their vicinity shown in FIG. 15B . Note that hereinafter, the etching process using the insulating layer 127 as a mask may be referred to as the second etching process.

[0568] The end of insulating layer 125 is covered with insulating layer 127. Also, Figures 15B and 16D show an example in which part of the end of mask layer 118b (specifically, the tapered portion formed by the first etching process) is covered with insulating layer 127, and the tapered portion formed by the second etching process is exposed. In other words, this corresponds to the structure shown in Figures 4A and 4B.

[0569] If the first etching process is not performed and the insulating layer 125 and the mask layer are etched together after post-baking, side etching may cause the insulating layer 125 and the mask layer below the edge of the insulating layer 127 to disappear, forming a cavity. Such a cavity may cause unevenness on the surface on which the common layer 114 and the common electrode 115 are formed, making the common layer 114 and the common electrode 115 more likely to be discontinuous. Even if the insulating layer 125 and the mask layer are side-etched in the first etching process, post-baking can subsequently fill the cavity with the insulating layer 127. The second etching process then etches the thinner mask layer, reducing the amount of side etching and making it less likely for a cavity to form. Even if a cavity does form, it can be extremely small. This allows the surface on which the common layer 114 and the common electrode 115 are formed to be more flat.

[0570] 5A, 5B, 7A, and 7B, the insulating layer 127 may cover the entire end of the mask layer 118b. For example, the end of the insulating layer 127 may droop and cover the end of the mask layer 118b. Furthermore, for example, the end of the insulating layer 127 may contact the top surface of at least one of the first layer 113a, the second layer 113b, and the third layer 113c. As described above, if the developed insulating layer 127b is not exposed to light, the shape of the insulating layer 127 may be easily deformed.

[0571] The second etching treatment is preferably performed by wet etching. By using a wet etching method, damage to the first layer 113 a, the second layer 113 b, and the third layer 113 c can be reduced compared to when a dry etching method is used. Wet etching can be performed using an alkaline solution or the like.

[0572] As described above, by providing the insulating layer 127, the insulating layer 125, the mask layer 118a, the mask layer 118b, and the mask layer 118c, it is possible to prevent poor connection between the light-emitting devices due to disconnection of the common layer 114 and the common electrode 115 and an increase in electrical resistance due to a locally thin portion of the film thickness. As a result, the display device of one embodiment of the present invention can have improved display quality.

[0573] Furthermore, after exposing parts of the first layer 113a, the second layer 113b, and the third layer 113c, further heat treatment may be performed. This heat treatment can remove water contained in the EL layer and water adsorbed to the surface of the EL layer. Furthermore, this heat treatment may change the shape of the insulating layer 127. Specifically, the insulating layer 127 may expand to cover at least one of the ends of the insulating layer 125, the ends of the mask layers 118a, 118b, and 118c, and the top surfaces of the first layer 113a, the second layer 113b, and the third layer 113c. For example, the insulating layer 127 may have the shape shown in FIGS. 5A and 5B. For example, heat treatment can be performed in an inert gas atmosphere or a reduced-pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., more preferably 70° C. to 120° C. A reduced pressure atmosphere is preferable because it allows dehydration at a lower temperature. However, it is preferable to appropriately set the temperature range for the heat treatment, taking into consideration the heat resistance temperature of the EL layer. In addition, when taking into consideration the heat resistance temperature of the EL layer, a temperature of 70°C or higher and 120°C or lower is particularly suitable within the above temperature range.

[0574] Next, the common layer 114, the common electrode 115, and the protective layer 131 are formed in this order over the insulating layer 127, the first layer 113a, the second layer 113b, and the third layer 113c. Furthermore, a substrate 120 is attached to the protective layer 131 using a resin layer 122, thereby manufacturing a display device (FIG. 3B).

[0575] The common layer 114 can be formed by a method such as a vapor deposition method (including a vacuum deposition method), a transfer method, a printing method, an inkjet method, or a coating method.

[0576] For example, sputtering or vacuum deposition can be used to form the common electrode 115. Alternatively, a film formed by deposition and a film formed by sputtering may be stacked.

[0577] The protective layer 131 can be formed by vacuum deposition, sputtering, CVD, ALD, or the like.

[0578] As described above, in the manufacturing method of the display device of this embodiment, the island-shaped first layer 113a, the island-shaped second layer 113b, and the island-shaped third layer 113c are formed by forming a film over the entire surface and then processing it, rather than using a fine metal mask. This allows the island-shaped layers to be formed with uniform thicknesses. This allows a high-resolution display device or a display device with a high aperture ratio to be realized. Furthermore, even if the resolution or aperture ratio is high and the distance between subpixels is extremely short, the first layer 113a, the second layer 113b, and the third layer 113c can be prevented from contacting each other in adjacent subpixels. Therefore, leakage current between subpixels can be suppressed. This prevents crosstalk due to unintended light emission, and a display device with extremely high contrast can be realized.

[0579] Furthermore, by providing the insulating layer 127 having a tapered edge between adjacent island-shaped EL layers, it is possible to suppress the occurrence of a step during the formation of the common electrode 115 and to prevent the formation of a locally thin portion in the common electrode 115. This can suppress the occurrence of a connection failure due to the disconnected portion in the common layer 114 and the common electrode 115 and an increase in electrical resistance due to the locally thin portion. Therefore, the display device of one embodiment of the present invention can achieve both high definition and high display quality.

[0580] This embodiment mode can be combined with other embodiment modes as appropriate.

[0581] Embodiment 4 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0582] [Pixel Layout] In this embodiment, pixel layouts different from that shown in Fig. 3A will be mainly described. There are no particular limitations on the arrangement of sub-pixels, and various methods can be applied. Examples of sub-pixel arrangements include a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0583] The top surface shape of the sub-pixels shown in the drawings in this embodiment corresponds to the top surface shape of the light-emitting region (or light-receiving region).

[0584] The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle.

[0585] Furthermore, the circuit layout constituting the subpixel is not limited to the range of the subpixel shown in the figure, and may be arranged outside the range. The arrangement of the circuits and the arrangement of the light-emitting devices do not necessarily have to be the same, and different arrangements may also be used. For example, the arrangement of the circuits may be a stripe arrangement, and the arrangement of the light-emitting devices may be an S-stripe arrangement.

[0586] An S-stripe arrangement is applied to the pixel 110 shown in Fig. 17A. The pixel 110 shown in Fig. 17A is composed of three sub-pixels, 110a, 110b, and 110c.

[0587] The pixel 110 shown in Figure 17B includes a subpixel 110a having a substantially triangular or trapezoidal top surface shape with rounded corners, a subpixel 110b having a substantially triangular or trapezoidal top surface shape with rounded corners, and a subpixel 110c having a substantially rectangular or hexagonal top surface shape with rounded corners. Furthermore, the subpixel 110b has a larger light-emitting area than the subpixel 110a. In this manner, the shape and size of each subpixel can be determined independently. For example, the more reliable the light-emitting device, the smaller the size of the subpixel can be.

[0588] The Pentile arrangement is applied to the pixels 124a and 124b shown in Fig. 17C. Fig. 17C shows an example in which a pixel 124a having sub-pixels 110a and 110b and a pixel 124b having sub-pixels 110b and 110c are arranged alternately.

[0589] 17D and 17E are pixels 124a and 124b that have a delta arrangement. Pixel 124a has two subpixels (subpixels 110a and 110b) in the top row (first row) and one subpixel (subpixel 110c) in the bottom row (second row). Pixel 124b has one subpixel (subpixel 110c) in the top row (first row) and two subpixels (subpixels 110a and 110b) in the bottom row (second row).

[0590] FIG. 17D shows an example in which each subpixel has a substantially rectangular top surface shape with rounded corners, and FIG. 17E shows an example in which each subpixel has a circular top surface shape.

[0591] 17F shows an example in which subpixels of each color are arranged in a zigzag pattern. Specifically, when viewed from above, the positions of the upper sides of two subpixels aligned in the column direction (for example, subpixels 110a and 110b, or subpixels 110b and 110c) are misaligned.

[0592] 17A to 17F, it is preferable that the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, and the subpixel 110c be the subpixel B that emits blue light. Note that the configuration of the subpixels is not limited to this, and the colors that the subpixels emit and their arrangement order can be determined appropriately. For example, the subpixel 110b may be the subpixel R that emits red light, and the subpixel 110a may be the subpixel G that emits green light.

[0593] In photolithography, the finer the pattern to be processed, the more significant the effect of light diffraction becomes. This reduces the fidelity of the photomask pattern when it is transferred by exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, it is likely to have rounded corners. As a result, the top surface shape of the subpixel may become a polygon with rounded corners, an ellipse, a circle, or the like.

[0594] Furthermore, in a manufacturing method of a display device according to one embodiment of the present invention, the EL layer is processed into an island shape using a resist mask. The resist film formed on the EL layer needs to be cured at a temperature lower than the heat resistance temperature of the EL layer. Therefore, depending on the heat resistance temperature of the material for the EL layer and the curing temperature of the resist material, the resist film may not be cured sufficiently. A resist film that is not cured sufficiently may have a shape that deviates from the desired shape during processing. As a result, the top surface shape of the EL layer may become a polygon with rounded corners, an ellipse, a circle, or the like. For example, when a resist mask with a square top surface shape is formed, a resist mask with a circular top surface shape may be formed, resulting in a circular top surface shape of the EL layer.

[0595] In order to form the top surface of the EL layer into a desired shape, a technique for correcting a mask pattern in advance (OPC (Optical Proximity Correction) technique) may be used so that the design pattern and the transfer pattern coincide with each other. Specifically, the OPC technique adds a correction pattern to the corners of figures on the mask pattern.

[0596] As shown in Figures 18A to 18I, a pixel can be configured to have four types of sub-pixels.

[0597] The pixels 110 shown in FIGS. 18A to 18C are arranged in a stripe pattern.

[0598] Figure 18A shows an example in which each subpixel has a rectangular top surface shape, Figure 18B shows an example in which each subpixel has a top surface shape that is a combination of two semicircles and a rectangle, and Figure 18C shows an example in which each subpixel has an elliptical top surface shape.

[0599] The pixels 110 shown in FIGS. 18D to 18F are arranged in a matrix.

[0600] Figure 18D is an example in which each sub-pixel has a square top surface shape, Figure 18E is an example in which each sub-pixel has an approximately square top surface shape with rounded corners, and Figure 18F is an example in which each sub-pixel has a circular top surface shape.

[0601] 18G and 18H show an example in which one pixel 110 is configured in two rows and three columns.

[0602] 18G has three subpixels (subpixels 110a, 110b, and 110c) in the top row (first row) and one subpixel (subpixel 110d) in the bottom row (second row). In other words, pixel 110 has subpixel 110a in the left column (first column), subpixel 110b in the center column (second column), subpixel 110c in the right column (third column), and subpixel 110d across these three columns.

[0603] The pixel 110 shown in FIG. 18H has three subpixels (subpixels 110a, 110b, and 110c) in the top row (first row) and three subpixels 110d in the bottom row (second row). In other words, the pixel 110 has subpixels 110a and 110d in the left column (first column), subpixels 110b and 110d in the center column (second column), and subpixels 110c and 110d in the right column (third column). By aligning the subpixels in the top and bottom rows as shown in FIG. 18H, it is possible to efficiently remove dust and other particles that may occur during the manufacturing process. Therefore, a display device with high display quality can be provided.

[0604] FIG. 18I shows an example in which one pixel 110 is configured in three rows and two columns.

[0605] 18I has subpixel 110a in the top row (first row), subpixel 110b in the middle row (second row), subpixel 110c across the first and second rows, and one subpixel (subpixel 110d) in the bottom row (third row). In other words, pixel 110 has subpixels 110a and 110b in the left column (first column), subpixel 110c in the right column (second column), and subpixel 110d across these two columns.

[0606] The pixel 110 shown in FIGS. 18A to 18I is composed of four sub-pixels 110a, 110b, 110c, and 110d.

[0607] The sub-pixels 110a, 110b, 110c, and 110d may each have a light-emitting device that emits light of a different color, such as sub-pixels of four colors R, G, B, and white (W), sub-pixels of four colors R, G, B, and Y, or sub-pixels of R, G, B, and infrared (IR).

[0608] 18A to 18I , it is preferable that, for example, the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, the subpixel 110c be the subpixel B that emits blue light, and the subpixel 110d be any one of the subpixels W that emit white light, Y that emit yellow light, and IR that emit near-infrared light. With such a configuration, the pixel 110 shown in FIGS. 18G and 18H has a stripe layout of R, G, and B, thereby improving display quality. Furthermore, the pixel 110 shown in FIG. 18I has a so-called S-stripe layout of R, G, and B, thereby improving display quality.

[0609] The pixel 110 may also have sub-pixels that include light-receiving devices.

[0610] In each pixel 110 shown in FIGS. 18A to 18I, any one of the subpixels 110a to 110d may be a subpixel having a light-receiving device.

[0611] 18A to 18I , it is preferable that, for example, the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, the subpixel 110c be the subpixel B that emits blue light, and the subpixel 110d be the subpixel S that has a light-receiving device. With this configuration, the pixels 110 shown in FIGS. 18G and 18H have a stripe layout of R, G, and B, which can improve display quality. Furthermore, the pixel 110 shown in FIG. 18I has a so-called S-stripe layout of R, G, and B, which can improve display quality.

[0612] The wavelength of light detected by the subpixel S having the light receiving device is not particularly limited. The subpixel S can be configured to detect either or both of visible light and infrared light.

[0613] As shown in Figures 18J and 18K, a pixel can be configured to have five types of sub-pixels.

[0614] FIG. 18J shows an example in which one pixel 110 is configured in two rows and three columns.

[0615] 18J has three subpixels (subpixels 110a, 110b, and 110c) in the top row (first row) and two subpixels (subpixels 110d and 110e) in the bottom row (second row). In other words, pixel 110 has subpixels 110a and 110d in the left column (first column), subpixel 110b in the center column (second column), subpixel 110c in the right column (third column), and subpixel 110e spanning from the second column to the third column.

[0616] FIG. 18K shows an example in which one pixel 110 is configured in three rows and two columns.

[0617] 18K has subpixel 110a in the top row (first row), subpixel 110b in the middle row (second row), subpixel 110c across rows 1 and 2, and two subpixels (subpixels 110d and 110e) in the bottom row (third row). In other words, pixel 110 has subpixels 110a, 110b, and 110d in the left column (first column), and subpixels 110c and 110e in the right column (second column).

[0618] 18J and 18K, it is preferable that the subpixel 110a be the subpixel R that emits red light, the subpixel 110b be the subpixel G that emits green light, and the subpixel 110c be the subpixel B that emits blue light. In this configuration, the pixel 110 shown in FIG. 18J has a stripe layout of R, G, and B, which can improve display quality. Furthermore, the pixel 110 shown in FIG. 18K has a so-called S-stripe layout of R, G, and B, which can improve display quality.

[0619] 18J and 18K, it is preferable to use a subpixel S having a light-receiving device in at least one of the subpixels 110d and 110e. When light-receiving devices are used in both the subpixels 110d and 110e, the configurations of the light-receiving devices may be different from each other. For example, the wavelength ranges of light detected may differ at least partially from each other. Specifically, one of the subpixels 110d and 110e may have a light-receiving device that mainly detects visible light, and the other may have a light-receiving device that mainly detects infrared light.

[0620] 18J and 18K, it is preferable that one of the subpixels 110d and 110e is a subpixel S having a light-receiving device, and the other is a subpixel having a light-emitting device that can be used as a light source. For example, it is preferable that one of the subpixels 110d and 110e is a subpixel IR that emits infrared light, and the other is a subpixel S having a light-receiving device that detects infrared light.

[0621] In a pixel having sub-pixels R, G, B, IR, and S, an image can be displayed using the sub-pixels R, G, and B, while the sub-pixel IR can be used as a light source to detect reflected infrared light emitted by the sub-pixel IR at the sub-pixel S.

[0622] As described above, the display device of one embodiment of the present invention can employ various layouts for a pixel having a subpixel including a light-emitting device. Furthermore, the display device of one embodiment of the present invention can employ a pixel having both a light-emitting device and a light-receiving device. In this case, various layouts can also be employed.

[0623] This embodiment mode can be combined with other embodiment modes as appropriate.

[0624] Embodiment 5 In this embodiment, a display device of one embodiment of the present invention will be described with reference to FIGS.

[0625] The display device of the present embodiment can be a high-definition display device, and can therefore be used, for example, as a display unit for a wristwatch-type or bracelet-type information terminal (wearable device), as well as a display unit for a wearable device that can be worn on the head, such as a head-mounted display (HMD) for VR, or a glasses-type AR device.

[0626] The display device of this embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of this embodiment can be used in electronic devices having relatively large screens, such as television devices, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproducing devices.

[0627] 19A shows a perspective view of a display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and may be any of the display devices 100B to 100F described below.

[0628] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display portion 281. The display portion 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel portion 284 (described later) can be viewed.

[0629] 19B is a perspective view schematically illustrating the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to the FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0630] The pixel section 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of Fig. 19B. The various configurations described in the previous embodiments can be applied to the pixel 284a. Fig. 19B shows an example in which the pixel 284a has a configuration similar to that of the pixel 110 shown in Fig. 3A.

[0631] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0632] One pixel circuit 283a is a circuit that controls the driving of multiple elements included in one pixel 284a. One pixel circuit 283a can be configured to have three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a source signal is input to the source. This realizes an active matrix display device.

[0633] The circuit portion 282 includes a circuit for driving each pixel circuit 283 a of the pixel circuit portion 283. For example, the circuit portion 282 preferably includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0634] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit portion 282. An IC may be mounted on the FPC 290.

[0635] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are provided overlapping below the pixel unit 284, thereby enabling the aperture ratio (effective display area ratio) of the display unit 281 to be extremely high. For example, the aperture ratio of the display unit 281 can be 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixels 284a can be arranged at an extremely high density, enabling the resolution of the display unit 281 to be extremely high. For example, it is preferable that the pixels 284a be arranged in the display unit 281 at a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and 20,000 ppi or less, or 30,000 ppi or less.

[0636] Because such a display module 280 has extremely high resolution, it can be suitably used in VR devices such as HMDs or eyeglass-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so even when the display unit is enlarged with lenses, the pixels are not visible, allowing for 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 displays. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

[0637] Display Device 100A The display device 100A shown in FIG. 20A includes a substrate 301, a light-emitting device 130R, a light-emitting device 130G, a light-emitting device 130B, a capacitor 240, and a transistor 310.

[0638] 19A and 19B. The stacked structure from the substrate 301 to the insulating layer 255c corresponds to the layer 101 including the transistor in Embodiment 1.

[0639] The transistor 310 has a channel formation region in a substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part 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 in which the substrate 301 is doped with impurities and functions as one of a source and a drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0640] An element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0641] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided over the insulating layer 261 .

[0642] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located therebetween. 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 a dielectric of the capacitor 240.

[0643] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0644] An insulating layer 255a is provided to cover the capacitor 240, an insulating layer 255b is provided on the insulating layer 255a, and an insulating layer 255c is provided on the insulating layer 255b. The light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B are provided on the insulating layer 255c. FIG. 20A shows an example in which the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B have a stacked structure similar to that shown in FIG. 3B. An insulator is provided in the region between adjacent light-emitting devices. In FIG. 20A and other figures, an insulating layer 125 and an insulating layer 127 on the insulating layer 125 are provided in this region.

[0645] A mask layer 118a is located on the first layer 113a of the light-emitting device 130R, a mask layer 118b is located on the second layer 113b of the light-emitting device 130G, and a mask layer 118c is located on the third layer 113c of the light-emitting device 130B.

[0646] The pixel electrodes 111a, 111b, and 111c are electrically connected to one of the source and drain of the transistor 310 via a plug 256 embedded in the insulating layers 243, 255a, 255b, and 255c, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. The height of the top surface of the insulating layer 255c and the height of the plug 256 are the same or approximately the same. Various conductive materials can be used for the plug. Figure 20A and other figures show an example in which the pixel electrode has a two-layer structure consisting of a reflective electrode and a transparent electrode on the reflective electrode.

[0647] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 131 with a resin layer 122. For details of the components from the light-emitting devices to the substrate 120, refer to Embodiment 1. The substrate 120 corresponds to the substrate 292 in FIG. 19A .

[0648] 20B is an example of a display device including light-emitting devices 130R and 130G and a light-receiving device 150. The light-receiving device 150 includes a pixel electrode 111d, a fourth layer 113d, a common layer 114, and a common electrode 115, which are stacked together. For details of the display device including the light-receiving device, reference can be made to Embodiments 2 and 7.

[0649] 21 has a configuration in which a transistor 310A and a transistor 310B, each having a channel formed in a semiconductor substrate, are stacked. Note that in the following description of the display device, descriptions of parts that are the same as those of the display device described above may be omitted.

[0650] The display device 100B has a configuration in which a substrate 301B on which a transistor 310B, a capacitor 240, and a light-emitting device are provided and a substrate 301A on which a transistor 310A is provided are bonded together.

[0651] Here, it is preferable to provide an insulating layer 345 on the lower surface of the substrate 301B. It is also preferable to provide an insulating layer 346 on the insulating layer 261 provided on the substrate 301A. The insulating layers 345 and 346 are insulating layers that function as protective layers and can suppress the diffusion of impurities into the substrates 301B and 301A. The insulating layers 345 and 346 can be made of an inorganic insulating film that can be used for the protective layer 131 or the insulating layer 332 described below.

[0652] The substrate 301B is provided with a plug 343 that penetrates the substrate 301B and an insulating layer 345. Here, it is preferable to provide an insulating layer 344 to cover the side surface of the plug 343. The insulating layer 344 is an insulating layer that functions as a protective layer and can suppress the diffusion of impurities into the substrate 301B. The insulating layer 344 can be an inorganic insulating film that can be used for the protective layer 131.

[0653] Furthermore, a conductive layer 342 is provided on the back surface (surface opposite to the substrate 120 side) of the substrate 301B, below the insulating layer 345. The conductive layer 342 is preferably provided so as to be embedded in the insulating layer 335. Furthermore, the lower surfaces of the conductive layer 342 and the insulating layer 335 are preferably flattened. Here, the conductive layer 342 is electrically connected to the plug 343.

[0654] On the other hand, in the substrate 301A, a conductive layer 341 is provided on an insulating layer 346. The conductive layer 341 is preferably provided so as to be embedded in the insulating layer 336. In addition, the upper surfaces of the conductive layer 341 and the insulating layer 336 are preferably flattened.

[0655] The substrate 301A and the substrate 301B are electrically connected by bonding the conductive layer 341 and the conductive layer 342. Here, by improving the flatness of the surface formed by the conductive layer 342 and the insulating layer 335 and the surface formed by the conductive layer 341 and the insulating layer 336, the conductive layer 341 and the conductive layer 342 can be favorably bonded to each other.

[0656] It is preferable to use the same conductive material for the conductive layers 341 and 342. For example, a metal film containing an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, or a metal nitride film containing the above elements (titanium nitride film, molybdenum nitride film, tungsten nitride film), etc., can be used. In particular, it is preferable to use copper for the conductive layers 341 and 342. This allows the use of Cu-Cu (copper-copper) direct bonding technology (technology that achieves electrical conductivity by connecting Cu (copper) pads together).

[0657] Display Device 100C A display device 100C shown in FIG. 22 has a configuration in which a conductive layer 341 and a conductive layer 342 are joined via a bump 347.

[0658] 22 , by providing a bump 347 between the conductive layer 341 and the conductive layer 342, the conductive layer 341 and the conductive layer 342 can be electrically connected. The bump 347 can be formed using a conductive material containing, for example, gold (Au), nickel (Ni), indium (In), tin (Sn), or the like. Alternatively, for example, solder may be used as the bump 347. An adhesive layer 348 may be provided between the insulating layer 345 and the insulating layer 346. When the bump 347 is provided, the insulating layer 335 and the insulating layer 336 may not be provided.

[0659] [Display Device 100D] A display device 100D shown in FIG. 23 differs from the display device 100A mainly in the configuration of the transistors.

[0660] The transistor 320 is a transistor (OS transistor) in which a metal oxide (also referred to as an oxide semiconductor) is used for a semiconductor layer in which a channel is formed.

[0661] The transistor 320 includes 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 .

[0662] 19A and 19B . The stacked structure from the substrate 331 to the insulating layer 255c corresponds to the layer 101 including the transistor in Embodiment 1. The substrate 331 can be an insulating substrate or a semiconductor substrate.

[0663] An insulating layer 332 is provided over a 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 being released from the semiconductor layer 321 toward the insulating layer 332. The insulating layer 332 can be, for example, a film through which hydrogen or oxygen is less likely to diffuse than a silicon oxide film, such as an aluminum oxide film, a hafnium oxide film, or a silicon nitride film.

[0664] A conductive layer 327 is provided over the insulating layer 332, and an insulating layer 326 is provided to cover the conductive layer 327. The conductive layer 327 functions as a first gate electrode of the transistor 320, and part of the insulating layer 326 functions as a first gate insulating layer. An oxide insulating film such as a silicon oxide film is preferably used for at least a portion of the insulating layer 326 that is in contact with the semiconductor layer 321. The top surface of the insulating layer 326 is preferably planarized.

[0665] The semiconductor layer 321 is provided over the insulating layer 326. The semiconductor layer 321 preferably includes a metal oxide (also referred to as an oxide semiconductor) film having semiconductor properties. A pair of conductive layers 325 is provided over and in contact with the semiconductor layer 321 and functions as a source electrode and a drain electrode.

[0666] An insulating layer 328 is provided to cover top surfaces and side surfaces of the pair of conductive layers 325 and side surfaces of the semiconductor layer 321, and an insulating layer 264 is provided over the insulating layer 328. The insulating layer 328 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 264 or the like into the semiconductor layer 321 and prevents oxygen from being released from the semiconductor layer 321. The insulating layer 328 can be an insulating film similar to the insulating layer 332.

[0667] Openings reaching the semiconductor layer 321 are provided in the insulating layer 328 and the insulating layer 264. Inside the openings, an insulating layer 323 and a conductive layer 324 are buried, which are in contact with side surfaces of the insulating layer 264, the insulating layer 328, and the conductive layer 325 and an 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.

[0668] The top surfaces of the conductive layer 324, the insulating layer 323, and the insulating layer 264 are planarized so that their heights are the same or approximately the same, and insulating layers 329 and 265 are provided to cover them.

[0669] The insulating layer 264 and the insulating layer 265 function as interlayer insulating layers. The insulating layer 329 functions as a barrier layer that prevents impurities such as water or hydrogen from diffusing from the insulating layer 265 or the like to the transistor 320. The insulating layer 329 can be formed using an insulating film similar to the insulating layer 328 and the insulating layer 332.

[0670] A plug 274 electrically connected to one of the pair of conductive layers 325 is provided to be embedded in the insulating layer 265, the insulating layer 329, and the insulating layer 264. Here, the plug 274 preferably includes a conductive layer 274a covering the side surfaces of the openings of the insulating layer 265, the insulating layer 329, the insulating layer 264, and the insulating layer 328 and part of the top surface of the conductive layer 325, and a conductive layer 274b in contact with the top surface of the conductive layer 274a. In this case, the conductive layer 274a is preferably made of a conductive material through which hydrogen and oxygen do not easily diffuse.

[0671] [Display Device 100E] A display device 100E illustrated in FIG. 24 has a stacked structure of a transistor 320A and a transistor 320B each including an oxide semiconductor as a semiconductor in which a channel is formed.

[0672] The transistor 320A, the transistor 320B, and the surrounding configurations thereof can be referred to the display device 100D.

[0673] Although two transistors including an oxide semiconductor are stacked here, the present invention is not limited to this structure, and for example, three or more transistors may be stacked.

[0674] [Display Device 100F] A display device 100F shown in FIG. 25 has a stacked structure of a transistor 310 in which a channel is formed in a substrate 301 and a transistor 320 in which a channel is formed and a semiconductor layer containing metal oxide.

[0675] An insulating layer 261 is provided to cover the transistor 310, and a conductive layer 251 is provided over the insulating layer 261. An insulating layer 262 is provided to cover the conductive layer 251, and a conductive layer 252 is provided over the insulating layer 262. The conductive layers 251 and 252 each function as wirings. An insulating layer 263 and an insulating layer 332 are provided to cover the conductive layer 252, and the transistor 320 is provided over the insulating layer 332. An insulating layer 265 is provided to cover the transistor 320, and a capacitor 240 is provided over the insulating layer 265. The capacitor 240 and the transistor 320 are electrically connected by a plug 274.

[0676] The transistor 320 can be used as a transistor that forms a pixel circuit. The transistor 310 can be used as a transistor that forms a pixel circuit or a driver circuit (gate line driver circuit, source line driver circuit) that drives the pixel circuit. The transistors 310 and 320 can be used as transistors that form various circuits such as an arithmetic circuit or a memory circuit.

[0677] By using this configuration, not only pixel circuits but also driving circuits etc. can be formed directly below the light-emitting device, making it possible to make the display device smaller than when driving circuits are provided around the periphery of the display area.

[0678] [Display Device 100G] FIG. 26 shows a perspective view of the display device 100G, and FIG. 27A shows a cross-sectional view of the display device 100G.

[0679] The display device 100G has a configuration in which a substrate 152 and a substrate 151 are bonded together. In Fig. 26, the substrate 152 is indicated by a dashed line.

[0680] The display device 100G includes a display portion 162, a connection portion 140, a circuit 164, wiring 165, and the like. Fig. 26 shows an example in which an IC 173 and an FPC 172 are mounted on the display device 100G. Therefore, the configuration shown in Fig. 26 can also be considered a display module including the display device 100G, an IC (integrated circuit), and an FPC.

[0681] The connection portion 140 is provided on the outside of the display portion 162. The connection portion 140 can be provided along one side or multiple sides of the display portion 162. There may be one or more connection portions 140. FIG. 26 shows an example in which the connection portion 140 is provided so as to surround the four sides of the display portion. The connection portion 140 electrically connects the common electrode of the light-emitting device and the conductive layer, and can supply a potential to the common electrode.

[0682] The circuit 164 can be, for example, a scanning line driver circuit.

[0683] The wiring 165 has a function of supplying signals and power to the display portion 162 and the circuit 164. The signals and power are input to the wiring 165 from the outside via the FPC 172 or input to the wiring 165 from the IC 173.

[0684] 26 shows an example in which an IC 173 is provided on a substrate 151 by a chip-on-glass (COG) method or a chip-on-film (COF) method. The IC 173 may be, for example, an IC having a scanning line driver circuit or a signal line driver circuit. The display device 100G and the display module may not include an IC. Alternatively, the IC may be mounted on an FPC by a COF method or the like.

[0685] Figure 27A shows an example of a cross section of the display device 100G when a portion of the area including the FPC 172, a portion of the circuit 164, a portion of the display unit 162, a portion of the connection portion 140, and a portion of the area including the end portion are cut away.

[0686] A display device 100G shown in FIG. 27A has, between a substrate 151 and a substrate 152, a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B.

[0687] The light-emitting devices 130R, 130G, and 130B each have the same layer structure as shown in Fig. 3B, except that the pixel electrodes have different configurations. For details of the light-emitting devices, see Embodiment 1.

[0688] The light-emitting device 130R includes a conductive layer 112a, a conductive layer 126a on the conductive layer 112a, and a conductive layer 129a on the conductive layer 126a. All or some of the conductive layers 112a, 126a, and 129a may be called pixel electrodes.

[0689] Light-emitting device 130G includes conductive layer 112b, conductive layer 126b on conductive layer 112b, and conductive layer 129b on conductive layer 126b.

[0690] Light-emitting device 130B includes conductive layer 112c, conductive layer 126c on conductive layer 112c, and conductive layer 129c on conductive layer 126c.

[0691] The conductive layer 112a is connected to a conductive layer 222b included in the transistor 205 through an opening provided in the insulating layer 214. An end of the conductive layer 126a is located...

Claims

1. a first light emitting device; and a second light-emitting device; and a first insulating layer; a second insulating layer; the first light-emitting device has a first pixel electrode, a common electrode, and a first intermediate layer; the first intermediate layer is located between the common electrode and the first pixel electrode; the first intermediate layer has a first layer and a second layer; the second layer is located between the first layer and the first pixel electrode; the second layer includes a first inorganic compound and a first organic compound; the first organic compound has an unshared electron pair; the first organic compound interacts with the first inorganic compound to form a half-occupied orbital; the second light-emitting device has a second pixel electrode, the common electrode, and a second intermediate layer; the second intermediate layer is located between the common electrode and the second pixel electrode; the second intermediate layer has a third layer and a fourth layer; the fourth layer is located between the third layer and the second pixel electrode; the fourth layer includes the first inorganic compound and the first organic compound; the first insulating layer covers a part of an upper surface and a side surface of the first intermediate layer and a part of an upper surface and a side surface of the second intermediate layer; the second insulating layer overlaps with a part of an upper surface and a side surface of the first intermediate layer and a part of an upper surface and a side surface of the second intermediate layer via the first insulating layer; an upper surface of the second insulating layer is covered with the common electrode; In a cross-sectional view, an end portion of the second insulating layer has a tapered shape with a taper angle of less than 90°, The second insulating layer covers at least a portion of a side surface of the first insulating layer.

2. a first light emitting device; and a second light-emitting device; and a first insulating layer; a second insulating layer; the first light-emitting device includes a first pixel electrode, a common electrode, a first unit, a second unit, and a first intermediate layer; the first unit is located between the first pixel electrode and the first intermediate layer; the second unit is located between the first intermediate layer and the common electrode, the first intermediate layer is located between the first unit and the second unit; the first intermediate layer has a first layer and a second layer; the second layer is located between the first layer and the first unit; the second layer includes a first inorganic compound and a first organic compound; the first organic compound has an unshared electron pair; the first organic compound interacts with the first inorganic compound to form a half-occupied orbital; the second light-emitting device includes a second pixel electrode, the common electrode, a third unit, a fourth unit, and a second intermediate layer; the third unit is located between the second pixel electrode and the second intermediate layer, the fourth unit is located between the second intermediate layer and the common electrode, the second intermediate layer is located between the fourth unit and the third unit; the second intermediate layer has a third layer and a fourth layer; the fourth layer is located between the third layer and the third unit; the fourth layer includes the first inorganic compound and the first organic compound; the first unit, the second unit, the third unit, and the fourth unit each contain a light-emitting material; the first insulating layer covers a part of an upper surface and a side surface of the second unit and a part of an upper surface and a side surface of the fourth unit; the second insulating layer overlaps with a part of an upper surface and a side surface of the second unit and a part of an upper surface and a side surface of the fourth unit via the first insulating layer; an upper surface of the second insulating layer is covered with the common electrode; In a cross-sectional view, an end portion of the second insulating layer has a tapered shape with a taper angle of less than 90°, The second insulating layer covers at least a portion of a side surface of the first insulating layer.

3. In claim 1 or claim 2, the second layer includes an unpaired electron; The unpaired electrons were measured using an electron spin resonance (ESR) spectrometer at 1×10 １６ spins / cm ３ 1x10 or more １８ spins / cm ３ The display device can be observed at the following spin densities:

4. In claim 3, The display device, wherein the unpaired electron has a g value in the range of 2.003 or more and 2.004 or less.

5. In claim 1 or claim 2, The display device, wherein the first organic compound has an electron-deficient heteroaromatic ring.

6. In claim 1 or claim 2, The display device, wherein the first organic compound has a lowest unoccupied molecular orbital (LUMO) level in the range of −3.6 eV to −2.3 eV.

7. 3. The display device according to claim 1, wherein the first inorganic compound contains a metal element and oxygen.

8. In claim 1 or claim 2, The display device, wherein the first inorganic compound contains lithium and oxygen.

9. In claim 1 or claim 2, The display device, wherein the first layer includes a material having electron accepting properties.

10. In claim 1 or claim 2, the first layer includes a material having an electron accepting property, The electrical resistivity of the first layer is 1×10 ２ [Ω・cm] or more 1×10 ８ [Ω·cm] or less.

11. In claim 1 or claim 2, A display device, wherein an end of the second insulating layer is located outside an end of the first insulating layer.

12. In claim 1 or claim 2, The second insulating layer has a convex curved upper surface.

13. In claim 1 or claim 2, A display device, wherein, in a cross-sectional view, the end portion of the first insulating layer has a tapered shape with a taper angle of less than 90°.

14. In claim 1 or claim 2, The second insulating layer has a concave curved surface on a side surface thereof.

15. In claim 1 or claim 2, a third insulating layer and a fourth insulating layer; the third insulating layer is located between an upper surface of the first intermediate layer and the first insulating layer; the fourth insulating layer is located between an upper surface of the second intermediate layer and the first insulating layer; A display device, wherein an end of the third insulating layer and an end of the fourth insulating layer are each located outside an end of the first insulating layer.

16. In claim 15, The second insulating layer covers at least a portion of a side surface of the third insulating layer and at least a portion of a side surface of the fourth insulating layer.

17. In claim 15, A display device, wherein, in a cross-sectional view, the end of the third insulating layer and the end of the fourth insulating layer each have a tapered shape with a taper angle of less than 90°.

18. In claim 1 or claim 2, a first insulating layer and a second insulating layer each having a portion overlapping an upper surface of the first pixel electrode and a portion overlapping an upper surface of the second pixel electrode;

19. In claim 1 or claim 2, the first intermediate layer covers a side surface of the first pixel electrode; The second intermediate layer covers a side surface of the second pixel electrode.

20. In claim 1 or claim 2, A display device, wherein, in a cross-sectional view, the end of the first pixel electrode and the end of the second pixel electrode each have a tapered shape with a taper angle of less than 90°.

21. In claim 1 or claim 2, the first insulating layer is an inorganic insulating layer, The display device, wherein the second insulating layer is an organic insulating layer.

22. In claim 1 or claim 2, The display device, wherein the first insulating layer comprises aluminum oxide.

23. In claim 1 or claim 2, The display device, wherein the second insulating layer comprises an acrylic resin.

24. In claim 1 or claim 2, the first light-emitting device has a fifth layer between the first intermediate layer and the common electrode; the second light-emitting device has the fifth layer between the second intermediate layer and the common electrode; The display device, wherein the fifth layer is located between the second insulating layer and the common electrode.

25. The display device according to claim 1 or 2; a display module having at least one of a connector and an integrated circuit.

26. A display module according to claim 25; An electronic device having at least one of a housing, a battery, a camera, a speaker, and a microphone.