Light emitting device, display device, and electronic apparatus

Abstract

Provided is a light-emitting device having good characteristics. There is provided a light emitting device of one of a plurality of light emitting devices formed on the same insulating surface, the light emitting device including a first electrode, a second electrode, and an organic compound layer, adjacent light emitting devices independently including the first electrode, the second electrode being commonly used by the adjacent light emitting devices, the organic compound layer is located between the first electrode and the second electrode, the organic compound layer comprises a light-emitting layer and an electron injection layer, the electron injection layer is located between the light-emitting layer and the second electrode, the adjacent light-emitting device independently comprises a light-emitting layer and an electron injection layer, and the edge of the light-emitting layer and the edge of the electron injection layer are consistent or approximately consistent. The electron injection layer includes a mixed layer including a metal, a first organic compound including a phenanthroline ring having an electron donating group, and a second organic compound including a pi-electron-deficient heteroaromatic ring.

Description

Technical Field

[0001] One aspect of the present invention relates to a light-emitting device, a light-emitting apparatus, a light-receiving apparatus, a display apparatus, an electronic device, a lighting apparatus, and an electronic device. Note that this aspect of the present invention is not limited to the aforementioned technical fields. The technical field of one aspect of the invention disclosed in this specification relates to an object, method, or manufacturing method. Furthermore, one aspect of the present invention relates to a process, machine, manufacture, or composition of matter. Therefore, specifically, examples of the technical field of one aspect of the present invention disclosed in this specification include semiconductor devices, liquid crystal display devices, lighting apparatuses, energy storage devices, memory devices, imaging apparatuses, methods for driving these devices, or methods for manufacturing these devices. Background Technology

[0002] In recent years, display devices have been expected to be used for a variety of purposes. Examples of applications as large display devices include home television sets (also known as televisions or television receivers), digital signage, and public information displays (PIDs). Additionally, research and development is underway for portable information terminals such as smartphones and tablets with touch panels.

[0003] In addition, there is a demand for high-definition display devices. As devices that require high-definition display, the development of devices for virtual reality (VR), augmented reality (AR), substitutional reality (SR), and mixed reality (MR) is very active.

[0004] As a display device, for example, a display device including a light-emitting device (also called a light-emitting element) is under development. Light-emitting devices (also called "EL devices" or "EL elements") that utilize the electroluminescence (hereinafter referred to as EL) phenomenon have the characteristics of being easy to achieve in thin and lightweight form; being able to respond to input signals at high speed; and being able to be driven by a DC constant voltage power supply, etc., and have been applied to display devices.

[0005] Patent Document 1 discloses a VR-oriented display device using organic EL devices (also known as organic EL elements). Additionally, Patent Document 2 discloses a light-emitting device with low driving voltage and high reliability, wherein a mixed film of a transition metal and an organic compound having non-shared electron pairs is used as the electron injection layer.

[0006] [Preliminary Technology Documents]

[0007] [Patent Literature]

[0008] [Patent Document 1] International Patent Application Publication No. 2018 / 087625

[0009] [Patent Document 2] Japanese Patent Application Publication No. 2018-201012 Summary of the Invention

[0010] The technical problem that the invention aims to solve

[0011] Vacuum evaporation (VEA), using metal masks, is widely employed as one method for fabricating organic semiconductor films into specified shapes. However, recently, with advancements in density and resolution, further improvements in the resolution of EEA have reached their limits due to various issues, such as positioning accuracy and substrate spacing. On the other hand, by utilizing lithography to process the shape of organic semiconductor films, denser patterns can be formed. Furthermore, since the aforementioned methods are easily scalable to large areas, research has been conducted on the fabrication of organic semiconductor films using lithography.

[0012] Note that when using lithography to process organic semiconductor films, the driving voltage of the light-emitting device may increase significantly or the current efficiency may decrease significantly due to the influence of oxygen or water in the atmosphere, or the chemical solutions or water in the process.

[0013] One objective of this invention is to provide a light-emitting device with excellent performance. Another objective of this invention is to provide a light-emitting device with high reliability. Yet another objective of this invention is to provide a novel light-emitting device.

[0014] Note that the description of these objectives does not preclude the existence of other objectives. Note that one embodiment of the invention does not necessarily require achieving all of the above objectives. Furthermore, objectives other than those described above are clearly present in the specification, drawings, and claims, and can be derived from the description in the specification, drawings, and claims.

[0015] means of solving technical problems

[0016] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, and an organic compound layer located between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer and an electron injection layer located between the light-emitting layer and the second electrode. The electron injection layer includes a mixed layer comprising a metal, a first organic compound, and a second organic compound. The first organic compound includes a phenanthroline ring having an electron-donating group, and the second organic compound includes a π-electron-deficient heteroaromatic ring.

[0017] Another aspect of the present invention is a light-emitting device formed on the same insulating surface as one of a plurality of light-emitting devices. The light-emitting device includes a first electrode, a second electrode, and an organic compound layer. Adjacent light-emitting devices independently include a first electrode, and a second electrode is shared by adjacent light-emitting devices. The organic compound layer is located between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer and an electron injection layer. The electron injection layer is located between the light-emitting layer and the second electrode. Adjacent light-emitting devices independently include a light-emitting layer and an electron injection layer. The edges of the light-emitting layer and the edges of the electron injection layer are consistent or substantially consistent. The electron injection layer includes a mixed layer comprising a metal, a first organic compound, and a second organic compound. The first organic compound includes a phenanthroline ring having an electron-donating group, and the second organic compound includes a π-electron-deficient heteroaromatic ring.

[0018] Another aspect of the present invention is a light-emitting device formed on the same insulating surface as one of a plurality of light-emitting devices. The light-emitting device includes a first electrode, a second electrode, and an organic compound layer. Adjacent light-emitting devices independently include a first electrode, and the second electrode is shared by adjacent light-emitting devices. The organic compound layer is located between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer, an electron transport layer, and an electron injection layer. The electron injection layer is located between the light-emitting layer and the second electrode, and the electron transport layer is located between the light-emitting layer and the electron injection layer. The electron injection layer is shared by adjacent light-emitting devices, and adjacent light-emitting devices independently include a light-emitting layer and an electron transport layer. The edge of the light-emitting layer and the edge of the electron injection layer are consistent or substantially consistent. The electron injection layer includes a mixed layer comprising a metal, a first organic compound, and a second organic compound. The first organic compound includes a phenanthroline ring having an electron-donating group, and the second organic compound includes a π-electron-deficient heteroaromatic ring.

[0019] Furthermore, in the light-emitting devices having the above-mentioned structures, the electron-donating group is preferably at least one of alkyl, alkoxy, aryloxy, alkylamino, arylamino, and heterocyclic amino groups.

[0020] Furthermore, in the light-emitting devices having the above-described structures, the phenanthroline ring is preferably a 1,10-phenanthroline ring, and at least one of the 4- and 7-positions has an electron-donating group.

[0021] Furthermore, in the light-emitting devices having the above-described structures, the acidity coefficient pKa of the first organic compound is preferably 8 or higher.

[0022] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, and an organic compound layer located between the first and second electrodes. The organic compound layer includes a light-emitting layer and an electron injection layer located between the light-emitting layer and the second electrode. The electron injection layer comprises a mixed layer containing a metal, a first organic compound, and a second organic compound. The first organic compound includes a phenanthroline ring, and the minimum electrostatic potential of the first organic compound is 0.0004e / a0 at the electron density distribution threshold. 3 The time is -0.085E h The second organic compound includes a π-electron-deficient heteroaromatic ring.

[0023] Another aspect of the present invention is a light-emitting device formed on the same insulating surface as one of a plurality of light-emitting devices. The light-emitting device includes a first electrode, a second electrode, and an organic compound layer. Adjacent light-emitting devices independently include a first electrode, and the second electrode is shared by adjacent light-emitting devices. The organic compound layer is located between the first and second electrodes and includes a light-emitting layer and an electron injection layer. The electron injection layer is located between the light-emitting layer and the second electrode. Adjacent light-emitting devices independently include a light-emitting layer and an electron injection layer. The edges of the light-emitting layer and the electron injection layer are consistent or substantially consistent. The electron injection layer includes a mixed layer comprising a metal, a first organic compound, and a second organic compound. The first organic compound includes a phenanthroline ring, and the minimum electrostatic potential of the first organic compound is at a threshold of 0.0004e / a0 in the electron density distribution. 3 The time is -0.085E h The second organic compound includes a π-electron-deficient heteroaromatic ring.

[0024] Another aspect of the present invention is a light-emitting device formed on the same insulating surface as one of a plurality of light-emitting devices. The light-emitting device includes a first electrode, a second electrode, and an organic compound layer. Adjacent light-emitting devices independently include a first electrode, and the second electrode is shared by adjacent light-emitting devices. The organic compound layer is located between the first and second electrodes and includes a light-emitting layer, an electron transport layer, and an electron injection layer. The electron injection layer is located between the light-emitting layer and the second electrode, and the electron transport layer is located between the light-emitting layer and the electron injection layer. The electron injection layer is shared by adjacent light-emitting devices, and each adjacent light-emitting device independently includes a light-emitting layer and an electron transport layer. The edges of the light-emitting layer and the electron injection layer are consistent or substantially consistent. The electron injection layer includes a mixed layer comprising a metal, a first organic compound, and a second organic compound. The first organic compound includes a phenanthroline ring, and the minimum electrostatic potential of the first organic compound is 0.0004e / a0 at the electron density distribution threshold. 3 The time is -0.085E h The second organic compound includes a π-electron-deficient heteroaromatic ring.

[0025] In light-emitting devices having the above-described structures, the spin density of the electron injection layer, measured by the electron spin resonance method, is preferably 5 × 10⁻⁶. 16 spins / cm 3 above.

[0026] In the light-emitting devices having the above-described structures, it is preferable that the spin density of the mixed film comprising the metal and the first organic compound, as measured by the electron spin resonance method, is 2 × 10⁻⁶. 16 spins / cm 3 The spin density of the mixed film containing the metal and the second organic compound, as measured by electron spin resonance, is 2 × 10⁻⁶. 16 spins / cm 3 the following.

[0027] Furthermore, in the light-emitting devices having the above-described structures, the second organic compound preferably includes a phenanthroline ring.

[0028] Furthermore, in light-emitting devices having the above-mentioned structures, the glass transition temperature (T) of the second organic compound is... g Preferably, the temperature is above 100℃.

[0029] Furthermore, in light-emitting devices having the above-mentioned structures, the metal is preferably located in Group 1, Group 3, Group 11 or Group 13 of the periodic table.

[0030] In addition, one aspect of the present invention is a light-emitting device having the above-described structures, wherein the organic compound layer includes a hole injection layer located between the first electrode and the light-emitting layer, the hole injection layer comprising a third organic compound and a fourth organic compound, the third organic compound being an organic compound comprising a π-electron-rich heteroaromatic ring or an aromatic amine, and the fourth organic compound being an organic compound having at least one of a halogen group and a cyano group, wherein the number of halogen groups and cyano groups is 4 or more.

[0031] In addition, one aspect of the present invention is a light-emitting device having the above-described structure, wherein the spin density of the hole injection layer, measured by electron spin resonance, is 1 × 10⁻⁶. 17 spins / cm 3 above.

[0032] In addition, one aspect of the present invention is a light-emitting device having the above-described structure, wherein the third organic compound has hole transport properties and the fourth organic compound has acceptor properties for the third organic compound.

[0033] In addition, one aspect of the present invention is a display device comprising: a light-emitting device having the above-described structures; and a transistor or substrate.

[0034] In addition, one aspect of the present invention is an electronic device, including: a display device having the above-described structures; and a detection unit, an input unit, or a communication unit.

[0035] Note that the display device in this specification includes image display devices that use light-emitting devices. Additionally, display devices sometimes include modules such as: modules where connectors, such as anisotropic conductive films or TCP (Tape Carrier Package), are mounted on the light-emitting devices on a substrate; modules where printed circuit boards are provided at the ends of the TCP; or modules where ICs (integrated circuits) are directly mounted on the light-emitting devices via COG (Chip On Glass) packaging. Furthermore, lighting devices, etc., sometimes include display devices.

[0036] Invention Effects

[0037] According to one aspect of the present invention, a light-emitting device with excellent characteristics can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device with high reliability can be provided. Additionally, according to one aspect of the present invention, a novel light-emitting device can be provided.

[0038] Note that the description of these effects does not preclude the existence of other effects. One aspect of the invention does not necessarily require all of the aforementioned effects. Effects other than those described above can be extracted from the specification, drawings, and claims.

[0039] Brief description of the attached figures

[0040] Figures 1A to 1C This is a diagram showing a light-emitting device.

[0041] Figure 2 This is a diagram showing a light-emitting device.

[0042] Figures 3A to 3C This is the analysis result of the spin density distribution in the ground state of the composite material.

[0043] Figure 4A and Figure 4B This is the analysis result of the electrostatic potential diagram of the organic compound in its ground state.

[0044] Figures 5A to 5C This is the analysis result of the electrostatic potential diagram of the composite material in its ground state.

[0045] Figures 6A to 6D This is a diagram showing a light-emitting device.

[0046] Figure 7A and Figure 7B These are the top view and cross-sectional view of the display device.

[0047] Figures 8A to 8D This is a diagram showing a light-emitting device.

[0048] Figures 9A to 9E This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0049] Figure 10A and Figure 10B This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0050] Figures 11A to 11D This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0051] Figures 12A to 12C This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0052] Figures 13A to 13C This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0053] Figures 14A to 14C This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0054] Figure 15A and Figure 15B This is a perspective view showing an example of the structure of a display module.

[0055] Figure 16A and Figure 16B This is a cross-sectional view showing an example of the structure of a display device.

[0056] Figures 17A to 17D This is a diagram illustrating an example of an electronic device.

[0057] Figures 18A to 18F This is a diagram illustrating an example of an electronic device.

[0058] Figure 19 This is a graph showing the brightness-current density characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3.

[0059] Figure 20 This is a diagram showing the brightness-voltage characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3.

[0060] Figure 21 This is a graph showing the current efficiency-brightness characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3.

[0061] Figure 22 This is a graph showing the current density-voltage characteristics of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3.

[0062] Figure 23 This is a diagram showing the electroluminescence spectra of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3.

[0063] Figure 24 This is the ESR spectrum of sample 1.

[0064] Figure 25 This is the ESR spectrum of sample 2.

[0065] Figure 26 This is a comparison of the ESR spectra of sample 3.

[0066] Figure 27 This is a comparison of the ESR spectrum of sample 4.

[0067] Figure 28 This is a comparison of the ESR spectrum of sample 5.

[0068] Figure 29 This is a comparison of the ESR spectra of sample 6.

[0069] Figure 30 The comparison is of the ESR spectrum of sample 7.

[0070] Figure 31 The comparison is of the ESR spectrum of sample 8.

[0071] Figure 32 The comparison is of the ESR spectrum of sample 9.

[0072] Figure 33 The ESR spectrum of the thin film formed by co-deposition of PCBBiF and OCHD-003 is shown.

[0073] Figure 34 It is PrdP2Phen 1 HNMR spectrum.

[0074] Methods of implementing the invention

[0075] The embodiments will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the following description, and those skilled in the art will readily understand that its methods and details can be varied in many ways without departing from the spirit and scope of the invention. Therefore, the present invention should not be construed as being limited to the contents described in the embodiments shown below.

[0076] Note that in the structure of the invention described below, the same reference numerals are used across different figures to denote the same parts or parts having the same function, and repeated descriptions are omitted. Additionally, when denoteing parts with the same function, the same shading lines are sometimes used without additional reference numerals.

[0077] Furthermore, for ease of understanding, the positions, sizes, and extents of the constituent elements shown in the accompanying drawings may not represent their actual positions, sizes, and extents. Therefore, the disclosed invention is not necessarily limited to the positions, sizes, and extents shown in the accompanying drawings.

[0078] Furthermore, depending on the situation or state, the "film" and "layer" can be interchanged. For example, a "conductive layer" can be changed into a "conductive film." Similarly, an "insulating film" can be changed into an "insulating layer."

[0079] Note that in this specification, etc., devices manufactured using metal masks or FMMs (Fine Metal Masks) are sometimes referred to as MM (Metal Mask) structure devices. Additionally, in this specification, devices manufactured without metal masks or FMMs are sometimes referred to as MML (Metal Mask Less) structure devices.

[0080] In this specification and other materials, holes or electrons are sometimes referred to as "carriers." Specifically, a hole injection layer or electron injection layer is sometimes called a "carrier injection layer," a hole transport layer or electron transport layer is called a "carrier transport layer," and a hole blocking layer or electron blocking layer is called a "carrier blocking layer." Note that the above-mentioned carrier injection layer, carrier transport layer, and carrier blocking layer may not be clearly distinguished. In addition, sometimes a single layer functions as two or three of the carrier injection layer, carrier transport layer, and carrier blocking layer.

[0081] In this specification, the light-emitting device (also referred to as a light-emitting element) includes an EL layer (also referred to as an organic compound layer) between a pair of electrodes. The EL layer includes at least a light-emitting layer. In this specification, one of the pair of electrodes is sometimes referred to as the pixel electrode and the other as the common electrode.

[0082] In this specification, a conical shape refers to a shape in which at least a portion of the side surface of a constituent element is inclined relative to the substrate surface. For example, it is preferable to have a region where the angle (also called the cone angle) formed by the inclined side surface and the substrate surface is less than 90°. Note that the side surface of the constituent element and the substrate surface do not necessarily have to be completely flat; they can also be approximately planar with slight curvature or approximately planar with slight irregularities.

[0083] Note that the display devices described in this specification include image display devices using organic EL devices. Additionally, display devices sometimes include modules such as: modules where the organic EL device is fitted with connectors such as anisotropic conductive films or TCP (TapeCarrier Package); modules where printed circuit boards are provided at the ends of the TCP; or modules where ICs (integrated circuits) are directly mounted on the organic EL device via COG (Chip On Glass) packaging. Furthermore, lighting devices and the like sometimes include display devices.

[0084] (Implementation Method 1)

[0085] In this embodiment, refer to Figures 1A to 5C This invention describes a light-emitting device according to one aspect of the present invention.

[0086] Figure 1A A schematic diagram of a light-emitting device 130 according to one embodiment of the present invention is shown. The light-emitting device 130 includes a first electrode 101 having an anode, a second electrode 102 having a cathode, and an organic compound layer 103. The organic compound layer 103 is located between the first electrode 101 and the second electrode 102.

[0087] Generally, the driving voltage is reduced by using a donor material (also known as an electron donor) in the electron injection layer of a light-emitting device. Specific examples of donor materials typically include alkali metals such as lithium (Li) or compounds of such alkali metals, which have low work functions. By incorporating the aforementioned electron injection layer containing a donor material into the light-emitting device, the electron injection barrier from the electrode to the organic compound layer can be lowered, thereby reducing the driving voltage of the light-emitting device. However, when this electron injection layer is affected by oxygen, water, chemicals, etc., it can sometimes cause a significant increase in the driving voltage of the light-emitting device or a significant decrease in current efficiency.

[0088] On the other hand, in one aspect of the invention, a combination of materials is used in the electron injection layer 115 to lower the electron injection barrier from the second electrode 102 to the organic compound layer 103. In this combination, a donor level (SOMO (Single Occupied Molecular Orbital) or HOMO (Highest Occupied Molecular Orbital) level) is formed when a first organic compound with electron-donating properties and non-shared electron pairs interacts with a metal, and the donor level acts as an electron donor for the second organic compound with electron transport properties. By employing this structure, the electron injection layer 115 can be resistant to oxygen, water, pharmaceutical solutions, etc. Therefore, even if the electron injection layer 115 is affected by oxygen, water, pharmaceutical solutions, etc., a light-emitting device with reduced driving voltage and high luminous efficiency can be achieved.

[0089] To illustrate one aspect of the light-emitting device of the present invention, Figure 1B This diagram shows two adjacent light-emitting devices, 130a and 130b, formed on the same insulating surface, included in a display device. Both light-emitting devices 130a and 130b are light-emitting devices whose organic compound layers are processed using photolithography.

[0090] The light-emitting device 130a is located on the insulating layer 175 and includes a first electrode 101a having an anode, a second electrode 102 having a cathode, and an organic compound layer 103a. The organic compound layer 103a is located between the first electrode 101a and the second electrode 102. In addition, the organic compound layer 103a includes at least a light-emitting layer 113a and an electron injection layer 115a located between the light-emitting layer 113a and the second electrode 102 and in contact with the second electrode 102.

[0091] Similarly, the light-emitting device 130b is located on the insulating layer 175 and includes a first electrode 101b having an anode, a second electrode 102 having a cathode, and an organic compound layer 103b. The organic compound layer 103b is located between the first electrode 101b and the second electrode 102. In addition, the organic compound layer 103b includes at least a light-emitting layer 113b and an electron injection layer 115b located between the light-emitting layer 113b and the second electrode 102 and in contact with the second electrode 102.

[0092] In the light-emitting device 130a, the organic compound layer 103a is fabricated using photolithography. Therefore, each layer of the organic compound layer 103a is separated from the organic compound layer 103b included in the adjacent light-emitting device 130b. Furthermore, the ends (edges) of each layer of the organic compound layer 103a are aligned or substantially aligned in a direction perpendicular to the substrate. For example, the edges of the light-emitting layer 113a and the electron injection layer 115a are aligned or substantially aligned in a direction perpendicular to the substrate.

[0093] Similarly, in the light-emitting device 130b, the organic compound layer 103b is fabricated using photolithography. Therefore, each layer of the organic compound layer 103b is separated from the organic compound layer 103a included in the adjacent light-emitting device 130a. Furthermore, the ends (edges) of each layer of the organic compound layer 103b are aligned or substantially aligned in a direction perpendicular to the substrate. For example, the edges of the light-emitting layer 113b and the electron injection layer 115b are aligned or substantially aligned in a direction perpendicular to the substrate.

[0094] The second electrode 102 is preferably formed after processing the organic compound layer 103a and the organic compound layer 103b using photolithography. That is, the second electrode 102 is preferably a continuous layer (also called a common layer) used by the light-emitting device 130a and the light-emitting device 130b.

[0095] Note that when processing using lithography with an electron injection layer containing a donor material as the interface of an organic compound layer, the driving voltage of the light-emitting device may increase significantly or the current efficiency may decrease significantly due to the influence of atmospheric oxygen or water, or chemical solutions or water in the process. However, in one aspect of the present invention, a combined material is used for electron injection layers 115a and 115b, in which a donor level (SOMO level or HOMO level) is formed when a first organic compound with electron-donating properties and non-shared electron pairs interacts with a metal, and the latter acts as an electron donor for a second organic compound with electron transport properties. By adopting this structure, electron injection layers 115a and 115b can be resistant to atmospheric oxygen or water, chemical solutions or water in the process, etc., during lithography processing. Therefore, even when processing using lithography with electron injection layer 115a or 115b as the interface of an organic compound layer, a light-emitting device with reduced driving voltage and high luminous efficiency can be achieved.

[0096] Furthermore, when processing organic compound layers using lithography, the distance d between each layer of organic compound layer 103a and each layer of organic compound layer 103b can be reduced compared to mask evaporation. Specifically, the distance d can be reduced to less than 10 μm, 8 μm or less, 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. Additionally, for example, by using an LSI exposure apparatus, the distance d can be reduced to, for example, less than 500 nm, less than 200 nm, less than 100 nm, or even less than 50 nm in silicon wafer processes.

[0097] Furthermore, it is preferable that an insulating layer 150 is provided between each layer of organic compound layer 103a and each layer of organic compound layer 103b. This allows each layer of organic compound layer 103a to be separated from each layer of organic compound layer 103b. In this case, it can also be said that the insulating layer 150 is provided in the region surrounded by the insulating layer 175, the ends of each layer of organic compound layer 103a, and the ends of organic compound layer 103b. In this case, it can also be said that there is a region where the insulating layer 150 contacts the second electrode 102. In addition, the insulating layer 150 may also be constructed by stacking two or more insulating layers. For example, the insulating layer 150 may also have the following structure: a second insulating layer is stacked on the first insulating layer that contacts the ends of each layer of organic compound layer 103a, the ends of organic compound layer 103b, and the insulating layer 175, in a manner that fills the recesses of the first insulating layer.

[0098] Although Figure 1B Examples of all layers in an organic compound layer fabricated using lithography are shown, but one aspect of the invention is not limited thereto. In a light-emitting device according to one aspect of the invention, other portions of the organic compound layer may be formed after a portion has been fabricated using lithography, thereby allowing the layer to be shared between light-emitting devices. By increasing the number of layers shared between light-emitting devices, manufacturing costs can be reduced.

[0099] Figure 1C Schematic diagrams of light-emitting devices 130c and 130d, which are other examples of two adjacent light-emitting devices formed on the same insulating surface, are shown. Both light-emitting devices 130c and 130d are light-emitting devices formed by processing the layers other than the electron injection layer 115 in the organic compound layer (including the electron transport layer, the light-emitting layer, the hole transport layer, the hole injection layer, etc.) using lithography.

[0100] The light-emitting device 130c is located on the insulating layer 175 and includes a first electrode 101c having an anode, a second electrode 102 having a cathode, and an organic compound layer 103c. The organic compound layer 103c is located between the first electrode 101c and the second electrode 102. Furthermore, the organic compound layer 103c includes at least a light-emitting layer 113c and an electron injection layer 115 located between and in contact with the second electrode 102. Additionally, the light-emitting device 130c shows an electron transport layer 114c between the light-emitting layer 113c and the electron injection layer 115.

[0101] Similarly, the light-emitting device 130d is located on the insulating layer 175 and includes a first electrode 101d having an anode, a second electrode 102 having a cathode, and an organic compound layer 103d. The organic compound layer 103d is located between the first electrode 101d and the second electrode 102. Furthermore, the organic compound layer 103d includes at least a light-emitting layer 113d and an electron injection layer 115 located between and in contact with the second electrode 102. Additionally, the light-emitting device 130d shows an electron transport layer 114d between the light-emitting layer 113d and the electron injection layer 115.

[0102] In the light-emitting device 130c, all layers of the organic compound layer 103c except for the electron injection layer 115 (including the light-emitting layer 113c and the electron transport layer 114c) are fabricated using photolithography. Therefore, the layers of the organic compound layer 103c except for the electron injection layer 115 are separated from the adjacent light-emitting device 130d. Furthermore, the ends (edges) of the layers of the organic compound layer 103c except for the electron injection layer 115 are consistent or substantially consistent in a direction perpendicular to the substrate.

[0103] Similarly, in the light-emitting device 130d, the layers other than the electron injection layer 115 in the organic compound layer 103d (including the light-emitting layer 113d and the electron transport layer 114d) are fabricated using photolithography. Therefore, the layers other than the electron injection layer 115 in the organic compound layer 103d are separated from the adjacent light-emitting device 130c. Furthermore, the ends (edges) of the layers other than the electron injection layer 115 in the organic compound layer 103d are consistent or substantially consistent in the direction perpendicular to the substrate.

[0104] In light-emitting devices 130c and 130d, a combined material is used in the electron injection layer 115. In this combination, a donor level (SOMO level or HOMO level) is formed when a first organic compound with electron-donating properties and non-shared electron pairs interacts with a metal, and the latter acts as an electron donor for a second organic compound with electron transport properties. By employing this structure, the electron injection layer 115 can be resistant to oxygen, water, and pharmaceutical solutions. Therefore, even if the electron injection layer 115 is affected by oxygen, water, pharmaceutical solutions, etc., a light-emitting device with reduced driving voltage and high luminous efficiency can be achieved.

[0105] The electron injection layer 115 and the second electrode 102 are preferably formed after processing the layers other than the electron injection layer 115 in the organic compound layer 103c (including the light-emitting layer 113c and the electron transport layer 114c) and the layers other than the electron injection layer 115 in the organic compound layer 103d (including the light-emitting layer 113d and the electron transport layer 114d) using lithography. That is, the electron injection layer 115 and the second electrode 102 are preferably a continuous layer shared by the light-emitting devices 130c and 130d. By increasing the number of layers shared between adjacent light-emitting devices in the organic compound layer, the manufacturing cost of the light-emitting device can be reduced.

[0106] Furthermore, when processing layers other than the electron injection layer of the organic compound layer using lithography, the distance d between the layers other than the electron injection layer 115 of the organic compound layer 103c and the layers other than the electron injection layer 115 of the organic compound layer 103d can be reduced compared to mask evaporation. Specifically, the distance d can be reduced to less than 10 μm, less than 8 μm, less than 5 μm, less than 3 μm, less than 2 μm, less than 1.5 μm, less than 1 μm, or less than 0.5 μm. Additionally, for example, by using an LSI exposure apparatus, the distance d can be reduced to less than 500 nm, less than 200 nm, less than 100 nm, or even less than 50 nm in the silicon wafer process.

[0107] Furthermore, preferably, an insulating layer 150 is provided between each layer of organic compound layer 103c other than the electron injection layer 115 and each layer of organic compound layer 103d other than the electron injection layer 115. This allows the layers of organic compound layer 103c other than the electron injection layer 115 to be separated from each layer of organic compound layer 103d other than the electron injection layer 115. In this case, the insulating layer 150 can also be described as being provided in the region surrounded by the insulating layer 175, the ends of each layer of organic compound layer 103c other than the electron injection layer 115, and the ends of each layer of organic compound layer 103d other than the electron injection layer 115. In this case, it can also be described as having a region where the insulating layer 150 contacts the electron injection layer 115. In addition, the insulating layer 150 can also be constructed by stacking two or more insulating layers. For example, the insulating layer 150 may also have the following structure: a second insulating layer is formed by stacking on the first insulating layer in a manner that fills the recesses of the first insulating layer, on the ends of each layer other than the electron injection layer 115 of the organic compound layer 103a, the ends of each layer other than the electron injection layer 115 of the organic compound layer 103b, and the insulating layer 175.

[0108] Notice, Figures 1A to 1C Examples are shown where each light-emitting device comprises only one electron injection layer, but one aspect of the invention is not limited thereto. A light-emitting device according to one aspect of the invention may also comprise two or more electron injection layers.

[0109] Figure 2 Schematic diagrams of light-emitting devices 130e and 130f are shown as other examples of two adjacent light-emitting devices formed on the same insulating surface. Note that both light-emitting devices 130e and 130f are light-emitting devices comprising two electron injection layers. Furthermore, both light-emitting devices 130e and 130f are light-emitting devices in which the layers other than the electron injection layer 115_2 in the organic compound layer are fabricated using lithography.

[0110] The light-emitting device 130e is located on the insulating layer 175 and includes a first electrode 101e having an anode, a second electrode 102 having a cathode, and an organic compound layer 103e. The organic compound layer 103e is located between the first electrode 101e and the second electrode 102. Furthermore, the organic compound layer 103e includes at least a light-emitting layer 113e, an electron injection layer 115e, and an electron injection layer 115_2. The electron injection layers 115e and 115_2 are located between the light-emitting layer 113e and the second electrode 102. The electron injection layer 115_2 is closer to the second electrode 102 and is in contact with the second electrode 102 than the electron injection layer 115e.

[0111] Similarly, the light-emitting device 130f is located on the insulating layer 175 and includes a first electrode 101f having an anode, a second electrode 102 having a cathode, and an organic compound layer 103f. The organic compound layer 103f is located between the first electrode 101f and the second electrode 102. Furthermore, the organic compound layer 103f includes at least a light-emitting layer 113f, an electron injection layer 115f, and an electron injection layer 115_2. The electron injection layers 115f and 115_2 are located between the light-emitting layer 113f and the second electrode 102. The electron injection layer 115_2 is closer to the second electrode 102 and is in contact with the second electrode 102 than the electron injection layer 115f.

[0112] In the light-emitting device 130e, all layers of the organic compound layer 103e except for the electron injection layer 115_2 are fabricated using photolithography. Therefore, the layers of the organic compound layer 103e except for the electron injection layer 115_2 are separated from the adjacent light-emitting device 130f. Furthermore, the ends (edges) of the layers of the organic compound layer 103e except for the electron injection layer 115_2 are aligned or substantially aligned in a direction perpendicular to the substrate. For example, the edge of the light-emitting layer 113e and the edge of the electron injection layer 115e are aligned or substantially aligned in a direction perpendicular to the substrate.

[0113] Similarly, in the light-emitting device 130f, all layers of the organic compound layer 103f except for the electron injection layer 115_2 are fabricated using photolithography. Therefore, all layers of the organic compound layer 103f except for the electron injection layer 115_2 are separated from the adjacent light-emitting device 130e. Furthermore, the ends (edges) of all layers of the organic compound layer 103f except for the electron injection layer 115_2 are aligned or substantially aligned in a direction perpendicular to the substrate. For example, the edge of the light-emitting layer 113f and the edge of the electron injection layer 115f are aligned or substantially aligned in a direction perpendicular to the substrate.

[0114] In light-emitting devices 130e and 130f, a combined material is used for electron injection layers 115e and 115f. In this combination, a donor level (SOMO or HOMO level) is formed when a first organic compound with electron-donating properties and non-shared electron pairs interacts with a metal, and the latter acts as an electron donor for a second organic compound with electron transport properties. By employing this structure, electron injection layers 115e and 115f can be resistant to atmospheric oxygen or water, and chemical solutions or water in the process, during lithography. Therefore, even when lithography is used with electron injection layers 115e or 115f as the boundary of the organic compound layer, a light-emitting device with reduced driving voltage and high luminous efficiency can be achieved.

[0115] In light-emitting devices 130e and 130f, there are no particular restrictions on the material used for the electron injection layer 115_2, as long as it is a material that can reduce the electron injection barrier from the second electrode 102 to the organic compound layer 103.

[0116] For example, a composite material is used in the electron injection layer 115_2, in which a donor level (SOMO level or HOMO level) is formed when a first organic compound with electron-donating properties and non-shared electron pairs interacts with a metal, and the latter acts as an electron donor for a second organic compound with electron transport properties. By employing this structure, the electron injection layer 115_2 can be resistant to oxygen, water, and pharmaceutical solutions. Therefore, even if the electron injection layer 115_2 is affected by oxygen, water, pharmaceutical solutions, etc., a light-emitting device with reduced driving voltage and high luminous efficiency can be achieved.

[0117] Alternatively, for example, a layer containing alkali metals, alkaline earth metals, rare earth metals, or their compounds or complexes as main components, such as lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), 8-hydroxyquinoline-lithium (Liq), ytterbium (Yb), etc., can be used as the electron injection layer 115_2. For example, when electron injection layers containing such donor materials are used as electron injection layers 115e and 115f, the processing of organic compound layers using lithography sometimes leads to a significant increase in the driving voltage of the light-emitting device or a significant decrease in the current efficiency. On the other hand, electron injection layer 115_2 is formed after processing all layers other than electron injection layer 115_2 in the organic compound layer using lithography, so even if an electron injection layer containing donor materials is used as electron injection layer 115_2, the characteristics of the light-emitting device can be prevented from deteriorating.

[0118] Note that, although Figure 1A , Figure 1B , Figure 1C and Figure 2 Examples are shown where each organic compound layer includes a single light-emitting layer, but the invention is not limited to this. Each organic compound layer may also include two or more light-emitting layers. For example, by employing organic compound layers with multiple light-emitting layers stacked between a pair of electrodes and an intermediate layer, a light-emitting device that emits high brightness while maintaining low current density and offers higher reliability can be achieved. Furthermore, a light-emitting device with low power consumption can also be realized. Additionally, although in Figure 1A , Figure 1B , Figure 1C and Figure 2Although not illustrated, each organic compound layer may include, in addition to the structures described above, a hole injection layer, a hole transport layer, an electron blocking layer, an electron transport layer, an intermediate layer, etc. Furthermore, each layer may be a stack of two or more layers.

[0119] Hereinafter, when describing the common elements among light-emitting devices 130 and 130a to 130f, they will sometimes be referred to as light-emitting device 130. Similarly, when describing the common elements among constituent elements such as electron injection layers 115a to 115f that are distinguished by letters, symbols with omitted letters will sometimes be used.

[0120] In one aspect of the invention, a composite material is used for the electron injection layer 115, in which a donor level (SOMO or HOMO level) is formed through the interaction of a first organic compound with electron-donating properties and non-shared electron pairs with a metal, and the latter acts as an electron donor for a second organic compound with electron transport properties. By employing such a structure, an electron injection layer 115 with good electron injection properties and resistance to atmospheric oxygen and water, as well as water and chemicals used in lithography processes, can be formed, thus enabling a light-emitting device with reduced driving voltage and high luminous efficiency.

[0121] Because metals with low work functions, such as alkali metals and alkaline earth metals, and their compounds are highly reactive with oxygen and water, their use in light-emitting devices processed using lithography can lead to decreased luminous efficiency, increased driving voltage, decreased driving lifetime, and the formation of non-luminous regions at the ends of the light-emitting parts, sometimes resulting in a decrease in the characteristics and reliability of the light-emitting device. However, in one aspect of the present invention, even when using alkali metals or alkaline earth metals or their compounds, stabilization is achieved through interaction with a first organic compound having electron-donating properties and non-shared electron pairs, and a second organic compound having electron transport properties. Therefore, an electron injection layer 115 resistant to atmospheric oxygen and water, as well as water and chemicals used in the lithography process, can be formed. When alkali metals or alkaline earth metals or their compounds are used as the metal in one aspect of the present invention, the donor level (SOMO level or HOMO level) formed by interaction with the first organic compound having electron-donating properties and non-shared electron pairs can be a high level, making it easier to supply electrons to the second organic compound. Therefore, the electron injection barrier from the second electrode 102 to the organic compound layer 103 can be lowered, allowing electrons injected from the second electrode 102 to be smoothly injected and transported to the light-emitting layer 113 side, which is preferred.

[0122] Furthermore, in one embodiment of the light-emitting device of the present invention, any one of the metal elements from Groups 3 to 11 and Groups 12 to 14 can be used as the metal. These metals have low reactivity with oxygen and water in the atmosphere, as well as water and chemicals used in the photolithography process. Therefore, when used in a light-emitting device, there is an advantage that there is less degradation caused by water and oxygen when using metals with low work functions. On the other hand, the metal elements from Groups 3 to 11 and Groups 12 to 14 are stable and have low electron injection, which can cause a decrease in the luminous efficiency of the light-emitting device, an increase in the driving voltage, and a decrease in the driving lifetime. However, in one embodiment of the present invention, even if any one of the metal elements from Groups 3 to 11 and Groups 12 to 14 is used, it interacts with a first organic compound that has electron-donating properties and non-shared electron pairs to form a donor level (SOMO level or HOMO level), thereby easily supplying electrons to a second organic compound that has electron transport properties. Therefore, the electron injection barrier from the second electrode 102 to the organic compound layer 103 can be lowered, allowing electrons injected from the second electrode 102 to be smoothly injected and transported to the light-emitting layer 113. Furthermore, an electron injection layer 115 resistant to atmospheric oxygen and water, as well as water and chemicals used in lithography processes, can be formed, which is preferred. Thus, one aspect of the present invention can provide a light-emitting device with good moisture resistance, water resistance, oxygen resistance, chemical resistance, low driving voltage, and high luminous efficiency.

[0123] When a first organic compound with electron-donating properties and non-shared electron pairs interacts with a metal, and the sum of the number of electrons in the compound and the metal is odd, the stability energy decreases, and the resulting donor level (SOMO or HOMO level) can become a high level, which is therefore preferred. Thus, when the number of electrons in the compound is even, the metal is preferably located in an odd-numbered group of the periodic table.

[0124] <Estimating spin density and electrostatic potential in the interaction between metals and organic compounds using quantum chemical calculations>

[0125] Here, quantum chemical calculations were used to analyze the spin density and electrostatic potential (ESP) of the interaction between a metal, a first organic compound with electron-donating properties and non-shared electron pairs, and a second organic compound with electron transport properties. In the calculations, 4,7-di-1-pyrrolidinyl-1,10-phenanthroline (abbreviated: Pyrrd-Phen) was used as the first organic compound, 2,9-di(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated: NBPhen) was used as the second organic compound, and silver (Ag) was used as the metal.

[0126] Gaussian09 was used as the quantum chemistry calculation program. The calculations were performed using an SGI8600 manufactured by HPE. Density Functional Theory (DFT) was used to calculate the most stable ground-state structures of the first and second organic monomers, composites of the first and second organic compounds and metals, and composites of the first, second, and metals. 6-311G(d,p) and LanL2DZ were used as basis functions, and B3LYP was used as the functional. The total energy of the DFT was expressed as the sum of potential energy, electrostatic energy between electrons, kinetic energy of electrons, and exchange-correlation energy, including all complex electron-electron interactions. In DFT, the calculation accuracy is high because a functional approximation of the exchange-correlation interaction is used, expressed as a single-electron potential in terms of electron density.

[0127] Figures 3A to 3C The diagram shows the analytical results of the ground-state spin density distribution of composites of the first organic compound (Pyrrd-Phen) and a metal (Ag), the second organic compound (NBPhen) and a metal (Ag), and composites of the first organic compound (Pyrrd-Phen), the second organic compound (NBPhen), and a metal (Ag). In the attached diagram, spheres represent atoms constituting the compounds, and cloud-like structures surrounding the atoms represent electron density distribution thresholds of 0.003e / a0 in atomic units. 3 (e represents the elementary charge (1e = 1.60218 × 10⁻⁶)) -19 C), a0 represents the Bohr radius (1a0 = 5.29177 × 10⁻⁶). -11 The spin density distribution at time m) is shown, representing the localization of the doublet ground state in the compound. Note that since the ground states of the first organic compound (Pyrrd-Phen) and the second organic compound (NBPhen) are singlet ground states, no spin density distribution is observed.

[0128] When the composite material of the first organic compound (Pyrrd-Phen) and the metal (Ag) is in a doublet ground state, the first organic compound (Pyrrd-Phen) and the metal (Ag) interact. The metal (Ag) becomes stable by coordinating with the two nitrogen atoms (nitrogen atoms at positions 1 and 10) in the 1,10-phenanthroline ring of the first organic compound (Pyrrd-Phen) that have non-shared electron pairs, thereby forming the composite material. Therefore, according to... Figure 3AIt is known that a portion of the spin from the unpaired electrons of the metal (Ag) is distributed on a portion of the 1,10-phenanthroline ring of the first organic compound (Pyrrd-Phen), particularly on the two nitrogen atoms (nitrogen atoms at positions 1 and 10) with non-shared electron pairs. However, due to the weak interaction, most of the spin is distributed on the metal (Ag).

[0129] Furthermore, when the composite material of the second organic compound (NBPhen) and the metal (Ag) is in a doublet ground state, the second organic compound (NBPhen) and the metal (Ag) interact. The metal (Ag) becomes stable by coordinating with the two nitrogen atoms (nitrogen atoms at positions 1 and 10) in the 1,10-phenanthroline ring of the second organic compound (NBPhen) and having non-shared electron pairs, thereby forming the composite material. Therefore, according to... Figure 3B It is known that a portion of the spin from the unpaired electrons of the metal (Ag) is distributed on a portion of the 1,10-phenanthroline ring of the second organic compound (NBPhen), particularly on the two nitrogen atoms (nitrogen atoms at positions 1 and 10) with non-shared electron pairs. However, due to the weak interaction, most of the spin density is distributed on the metal (Ag).

[0130] On the other hand, in one embodiment of the present invention, when the composite material of the first organic compound (Pyrrd-Phen), the second organic compound (NBPhen), and the metal (Ag) is in a doublet ground state, the first organic compound (Pyrrd-Phen), the second organic compound (NBPhen), and the metal (Ag) interact. The metal (Ag) becomes stable by coordinating with the two nitrogen atoms (nitrogen atoms at positions 1 and 10) with non-shared electron pairs in the 1,10-phenanthroline ring of the first organic compound (Pyrrd-Phen) and the two nitrogen atoms (nitrogen atoms at positions 1 and 10) with non-shared electron pairs in the 1,10-phenanthroline ring of the second organic compound (NBPhen), thereby forming the composite material. Thus, according to Figure 3C It can be seen that the spins of the unpaired electrons originating from the metal (Ag) are locally distributed on the second organic compound (NBPhen). Furthermore, no spin density distribution of the metal (Ag) is observed. Therefore, it can be concluded that due to the interactions between the first organic compound (Pyrrd-Phen), the second organic compound (NBPhen), and the metal (Ag), the second organic compound (NBPhen) is in a radical anionic state.

[0131] then, Figure 4A , Figure 4B , Figures 5A to 5CThe analysis results of the ground-state electrostatic potential diagrams for the first organic compound (Pyrrd-Phen), the second organic compound (NBPhen), the composite material of the first organic compound (Pyrrd-Phen) and a metal (Ag), the composite material of the second organic compound (NBPhen) and a metal (Ag), and the composite material of the first organic compound (Pyrrd-Phen), the second organic compound (NBPhen) and a metal (Ag) are shown in the attached figures. In the figures, spheres represent atoms constituting the compounds, and cloud-like structures surrounding the atoms represent electron density distribution thresholds of 0.003e / a0 in the atomic unit system. 3 Electrostatic potential is the electrostatic potential in the electron density distribution of a molecule. Electrostatic potential is the interaction energy between a positive point charge of unit charge and the electron distribution of a molecule. An electrostatic potential diagram uses colors to represent the electrostatic potential in a surface with equal electron density. In the electrostatic potential diagram, red and blue represent regions with negative and positive electrostatic potential, respectively. Atoms in regions with negative electrostatic potential have negative charges, and atoms in regions with positive electrostatic potential have positive charges. Note that because... Figures 4A to 5C This is an image converted from the electrostatic potential diagram obtained through analysis to a grayscale image. Therefore, to represent regions with negative and positive electrostatic potential, a thick dashed line surrounds the dark red area (i.e., areas with negative electrostatic potential), and a thin dashed line surrounds the dark blue area (i.e., areas with positive electrostatic potential). Note that in... Figures 4A to 5C In the image, the dark red portion of the electrostatic potential diagram before conversion to grayscale is surrounded by a thick dashed line, while the dark blue portion is surrounded by a thin dashed line.

[0132] like Figure 4A As shown, in the singlet ground state of the first organic compound (Pyrrd-Phen), the electrostatic potential around the two nitrogen atoms (nitrogen atoms at positions 1 and 10) with non-shared electron pairs in the 1,10-phenanthroline ring is negative. Furthermore, the Mulliken partial charge of each of these two N atoms is negative, i.e., -0.29e. Therefore, it can be concluded that these two N atoms possess negative partial charges.

[0133] like Figure 4B As shown, in the singlet ground state of the second organic compound (NBPhen), the electrostatic potential around the two nitrogen atoms (nitrogen atoms at positions 1 and 10) with non-shared electron pairs in the 1,10-phenanthroline ring is negative. Furthermore, the Mulliken partial charge of each of these two N atoms is negative in atomic units, specifically -0.34e. Therefore, it can be concluded that the N atom possesses a negative partial charge.

[0134] In the double ground state of the composite material of the first organic compound (Pyrrd-Phen) and the metal (Ag), the first organic compound (Pyrrd-Phen) and the metal (Ag) interact, and the metal (Ag) becomes stable by coordinating with the two N atoms (nitrogen atoms (N) at positions 1 and 10) in the 1,10-phenanthroline ring of the first organic compound (Pyrrd-Phen) with non-shared electron pairs, thereby forming the composite material. As a result, as... Figure 5A As shown, the electrostatic potential around the two N atoms (nitrogen atoms at positions 1 and 10) and the metal (Ag) in the 1,10-phenanthroline ring of the first organic compound (Pyrrd-Phen) is negative. Furthermore, the Mulliken partial charge of each of the two N atoms is negative in atomic units, i.e., -0.37e, and the Mulliken partial charge of the metal (Ag) is negative in atomic units, i.e., -0.18e. Therefore, it can be concluded that the N and Ag atoms possess negative partial charges.

[0135] In the double ground state of the composite material of the second organic compound (NBPhen) and the metal (Ag), the second organic compound (NBPhen) and the metal (Ag) interact, and the metal (Ag) becomes stable by coordinating with the two N atoms (nitrogen atoms (N) at positions 1 and 10) in the 1,10-phenanthroline ring of the second organic compound (NBPhen) and having non-shared electron pairs, thereby forming the composite material. As a result, as... Figure 5B As shown, the electrostatic potentials around the two N atoms (nitrogen atoms at positions 1 and 10) and the metal (Ag) in the 1,10-phenanthroline ring of the second organic compound (NBPhen) are negative. Furthermore, the Mulliken partial charges of the two N atoms are negative in atomic units, specifically -0.45e and -0.39e, respectively, and the Mulliken partial charge of the metal (Ag) is negative in atomic units, specifically -0.06e. Therefore, it can be concluded that the two N atoms and the Ag atom possess negative partial charges.

[0136] On the other hand, in one embodiment of the present invention, when the composite material of the first organic compound (Pyrrd-Phen), the second organic compound (NBPhen), and the metal (Ag) is in a doublet ground state, the first organic compound (Pyrrd-Phen), the second organic compound (NBPhen), and the metal (Ag) interact. The metal (Ag) becomes stable by coordinating with the two N atoms (nitrogen atoms (N) at positions 1 and 10) of the 1,10-phenanthroline ring of the first organic compound (Pyrrd-Phen) and the two N atoms (nitrogen atoms (N) at positions 1 and 10) of the 1,10-phenanthroline ring of the second organic compound (NBPhen), thereby forming the composite material. As a result, as Figure 5C As shown, the positive electrostatic potential is mainly distributed around the metal (Ag) and the first organic compound (Pyrrd-Phen), while the negative electrostatic potential is mainly distributed around the second organic compound (NBphen). Furthermore, it is known that the electrostatic potential around the two N atoms with non-shared electron pairs (the nitrogen atoms at positions 1 and 10) in the 1,10-phenanthroline ring of the second organic compound (NBphen) is negative, while the electrostatic potential around the metal (Ag) is positive. Additionally, the Mulliken partial charge of these two N atoms is negative in atomic units, i.e., -0.52e, while the Mulliken partial charge of the metal (Ag) is positive in atomic units, i.e., 0.39e. Therefore, the charge of the Ag atom is distributed over these two N atoms.

[0137] Therefore, the following combination is formed: a donor level is formed through the interaction of a first organic compound with electron-donating properties and non-shared electron pairs with a metal, and a second organic compound with electron-transporting properties acts as an electron donor. In one aspect of the invention, by using a composite material having this combination in the electron injection layer 115, an electron injection layer 115 with good electron injection properties and resistance to atmospheric oxygen and water, as well as water and chemicals used in lithography processes, can be formed, thus enabling a light-emitting device with reduced driving voltage and high luminous efficiency.

[0138] <Estimating SOMO or HOMO levels in the interaction between metals and organic compounds using quantum chemical calculations>

[0139] Next, quantum chemical calculations are used to estimate the stability energy of the interaction between a metal, a first organic compound with electron-donating properties and non-shared electron pairs, and a second organic compound with electron transport properties, as well as the SOMO or HOMO energy levels formed at this time.

[0140] Gaussian09 was used as the quantum chemical calculation program. The calculations were performed using an SGI8600 manufactured by HPE. First, density functional theory (DFT) was used to calculate the most stable ground-state structures of the first organic compound, the second organic compound, and the metal; the composite of the first organic compound and the metal; the composite of the second organic compound and the metal; and the composite of the first organic compound, the second organic compound, and the metal. 6-311G(d,p) and LanL2DZ were used as basis functions, and B3LYP was used as the functional. Next, the stability energy was calculated based on the difference between the total energy of the composite of the organic compound and the metal and the sum of the total energies of the organic compound monomers and the metal monomers. In other words, the stability energy = (total energy of the composite of the organic compound and the metal) - (total energy of the organic compound monomers) - (total energy of the metal monomers) holds true.

[0141] The following tables present the following calculation results: the stability energies of composites of the first organic compound and the metal, composites of the second organic compound and the metal, and composites of the first organic compound, the second organic compound, and the metal; and the HOMO or SOMO energy levels of the first organic compound, the second organic compound, composites of the first organic compound and the metal, composites of the second organic compound and the metal, and composites of the first organic compound, the second organic compound, and the metal. Note that the HOMO and SOMO energy levels in each table are calculated values ​​and may sometimes differ from measured values.

[0142] First, the following results are presented using 4,7-di-1-pyrrolidinyl-1,10-phenanthroline (abbreviated as Pyrrd-Phen) as the first organic compound, 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P) as the second organic compound, and zinc (Zn) as the metal.

[0143] [Table 1]

[0144]

[0145] As shown in the table above, the stability energies of the composite materials of metal (Zn) and the first organic compound (Pyrrd-Phen), as well as the composite material of metal (Zn) and the second organic compound (mPPhen2P), are negative. When either the first or second organic compound is mixed with a metal, the organic compound interacts with the metal, thus resulting in greater energy stability compared to using only the single organic compound, although the difference is small. Furthermore, the difference between the HOMO energy levels formed at this point and the individual HOMO energy levels of the first organic compound (Pyrrd-Phen) and the second organic compound (mPPhen2P) is small, indicating weak interactions between the organic compounds and the metal.

[0146] On the other hand, it is known that the stability energy of the composite material of metal (Zn), first organic compound (Pyrrd-Phen), and second organic compound (mPPhen2P) in one aspect of the present invention is lower than that of the composite material of metal (Zn) and first organic compound (Pyrrd-Phen) and the composite material of metal (Zn) and second organic compound (mPPhen2P), thus exhibiting energy stability. Therefore, the stability energy of the composite material of first organic compound, second organic compound, and metal is preferably -0.50 eV or less, more preferably -1.0 eV or less, -2.0 eV or less, -3.0 eV or less, or -4.0 eV or less. Furthermore, the HOMO energy level formed at this time is higher than the individual HOMO energy levels of the first organic compound (Pyrrd-Phen) and the second organic compound (mPPhen2P). A higher HOMO energy level results in better electron injection performance, which is therefore preferred.

[0147] Next, the results of calculations are shown below, using Pyrrd-Phen as the first organic compound, mPPhen2P as the second organic compound, and calcium (Ca) or magnesium (Mg) as the metal.

[0148] [Table 2]

[0149]

[0150] As shown in the table above, when alkaline earth metals (Ca, Mg) are used as the metal, the composite material of the metal, the first organic compound, and the second organic compound has a stability energy below -2.0 eV, thus exhibiting greater energy stability and is therefore preferred. Furthermore, the HOMO energy level formed at this time is higher than the individual HOMO energy levels of the first and second organic compounds. A higher HOMO energy level results in better electron injection, and is therefore preferred.

[0151] Next, the results of the calculations are shown below under the following conditions: Pyrrd-Phen is used as the first organic compound, mPPhen2P is used as the second organic compound, and a metal located in an odd group (Group 1, Group 3, Group 5, Group 7, Group 9, Group 11 or Group 13) is used as the metal, specifically lithium (Li), aluminum (Al), silver (Ag), copper (Cu) or indium (In).

[0152] [Table 3]

[0153]

[0154] As shown in the table above, when using metals from odd-numbered groups, the composite material of the metal, the first organic compound, and the second organic compound has a stability energy below -1.0 eV, -2.0 eV, -3.0 eV, or -4.0 eV, thus exhibiting greater energy stability and is therefore preferred. Furthermore, the SOMO energy level formed at this time is higher than the HOMO energy levels of the first and second organic compounds respectively. A higher SOMO energy level results in better electron injection performance, and is therefore preferred.

[0155] Note that, considering the manufacturing process of light-emitting devices, the organic compound layer of the light-emitting device is generally deposited using vacuum evaporation in many cases. As the material used in this process, materials that can be easily vacuum-deposited, i.e., materials with low melting points, are preferred. Because metals belonging to Group 11 and Group 13 elements have low melting points, they are suitable for vacuum evaporation. Furthermore, metals belonging to Group 11 and Group 13 elements are stable to atmospheric oxygen and water, making them preferred. Additionally, vacuum evaporation allows for easy mixing of metal atoms and organic compounds, which is also preferred.

[0156] Alternatively, Ag or In can also be used as cathode materials. Using the same materials for both the electron injection layer 115 and the cathode allows for easy fabrication of light-emitting devices, making it a preferred option. Furthermore, it reduces the manufacturing cost of the light-emitting device.

[0157] Next, the detailed structure of the electron injection layer 115, which can be used in light-emitting devices 130a and 130b, will be described.

[0158] <<Structure of the Electron Injection Layer>>

[0159] The electron injection layer 115 is preferably a mixed layer comprising a metal, a first organic compound, and a second organic compound (details of which will be described later). The metal and the first organic compound are combined in such a way that they can interact to form donor levels (SOMO or HOMO levels) and can act as electron donors relative to the second organic compound, which has electron transport properties. By using a layer comprising these materials as the electron injection layer 115, the electron injection barrier from the second electrode 102 to the organic compound layer 103 can be lowered, allowing electrons injected from the second electrode 102 to be smoothly injected and transported to the light-emitting layer 113. This provides a light-emitting device with low driving voltage and high light emission efficiency, and is therefore preferred.

[0160] Preferably, a hybrid layer comprising a metal, a first organic compound, and a second organic compound is used for the electron injection layer 115. When a hybrid layer is formed using a metal, a first organic compound, and a second organic compound, these substances readily interact, with the first organic compound and the metal acting as electron donors for the second organic compound. This further reduces the electron injection barrier from the second light-emitting unit side to the first light-emitting unit side. Consequently, electrons are more easily injected into the first light-emitting unit, further reducing the driving voltage of the light-emitting device and further improving luminous efficiency. Furthermore, when a hybrid layer is formed using a metal, a first organic compound, and a second organic compound, a layer less prone to crystallization can be formed compared to a multilayer structure. Therefore, a layer less prone to crystallization can be achieved even when a portion of the organic compound layer is processed using lithography, despite the influence of atmospheric oxygen or water, or chemical solutions or water during the process. This prevents an increase in the driving voltage or a decrease in current efficiency of the light-emitting device due to crystallization of the electron injection layer 115. Therefore, compared to a multilayer structure, by using a hybrid layer, a composite material comprising a metal, a first organic compound, and a second organic compound can be applied to the electron injection layer 115 of a light-emitting device in which a portion of the organic compound layer is processed using lithography.

[0161] <Metal>

[0162] As a metal, either a typical metal or a transition metal can be used.

[0163] Typical metals include alkali metals (Group 1 elements) such as Li, Na, K, and Cs; alkaline earth metals (Group 2 elements) such as Mg, Ca, and Ba; Group 12 elements such as Zn; earth metals (Group 13 elements) such as Al and In; Group 14 elements such as Sn; or their compounds.

[0164] When alkali metals or alkaline earth metals or their compounds are used as metals, the donor level formed by the interaction with the first organic compound can be high-energy, which can easily supply electrons to the second organic compound. Thus, electrons injected from the second electrode 102 can be smoothly injected and transported to the light-emitting layer 113 side, which can provide a light-emitting device with low driving voltage and high light emission efficiency, so it is preferred.

[0165] As transition metals, Group 3 elements including lanthanides such as Y, Eu, and Yb; Group 7 elements such as Mn; Group 8 elements such as Fe; Group 9 elements such as Co; Group 10 elements such as Ni and Pt; Group 11 elements such as Cu, Ag, and Au, or their compounds can be used. Transition metals have low reactivity with atmospheric components such as water and oxygen, and are therefore preferred.

[0166] Of the aforementioned metals, those located in odd-numbered groups (Groups 1, 3, 5, 7, 9, 11, or 13) are more preferred. Among these odd-numbered transition metals, those with one electron (unpaired electron) in their outermost orbital readily form SOMO levels with first organic compounds and are therefore particularly preferred.

[0167] Furthermore, metals with low melting points that can be deposited using vacuum evaporation are preferred as they readily form mixed layers with organic compounds. Specifically, for example, metals belonging to Group 11 and Group 13 elements have low melting points, making them suitable for vacuum evaporation. Additionally, metals belonging to Group 11 and Group 13 elements are stable to atmospheric oxygen and water, making them preferred as well.

[0168] <First Organic Compound>

[0169] As the first organic compound, an organic compound including a phenanthrene ring can be used.

[0170] In particular, among organic compounds including phenanthroline rings, organic compounds having a 1,10-phenanthroline ring have two nitrogen atoms that can coordinate with a metal and thus readily interact with the metal, making them preferred.

[0171] Furthermore, as the first organic compound, an organic compound comprising a phenanthroline ring having an electron-donating group is more preferred. In particular, by introducing an electron-donating group onto the 1,10-phenanthroline ring, the electron density of the phenanthroline ring can be increased, thereby improving the efficiency of interaction with the metal. Moreover, it is preferable that an electron-donating group is present at at least one of the 4 and 7 positions of the 1,10-phenanthroline ring. By introducing electron-donating groups at the 4 and 7 positions, the electron density of the nitrogen atoms at the 1 and 10 positions can be increased. Additionally, steric hindrance around the nitrogen atoms at the 1 and 10 positions can be avoided, and the electron density around them can be increased. Therefore, interaction with the metal can be facilitated, and this is preferred.

[0172] Furthermore, it is preferable that the minimum electrostatic potential (ESP) of the first organic compound is small (negative and large in absolute value), thus improving the efficiency of its interaction with the metal. In organic compounds with a phenanthroline ring, the ESP around the nitrogen atom of the phenanthroline ring tends to be negative, but by introducing an electron-donating group onto the phenanthroline ring, the ESP around the nitrogen atom of the phenanthroline ring can be further reduced (increasing the absolute value of the negative value). ESP refers to the interaction energy between a positive point charge of unit charge and the electron distribution of a molecule. Furthermore, the value of the ESP varies depending on the threshold of the electron density distribution. To improve the efficiency of its interaction with the metal, the minimum ESP of the first organic compound is preferably smaller than the minimum ESP of the unsubstituent phenanthroline ring (larger in the negative direction). Specifically, when the threshold of the electron density distribution in the atomic unit system is 0.0004e / a0... 3 At this time, the minimum value of the electrostatic potential is preferably -0.085E. h (E) h Hartley energy (1E) h =27.211eV or less, more preferably -0.090E h Below. Additionally, when the threshold for electron density distribution is 0.003e / a0 3 At this time, the minimum value of the electrostatic potential is preferably -0.12E. h Hereinafter, -0.13E is preferred. h the following.

[0173] Furthermore, when the first organic compound has a high alkalinity, it can significantly reduce the hole transport property of the electron injection layer 115 by interacting with holes, thereby preventing holes from being transported from the electron injection layer 115 to the second electrode 102. This results in a high-efficiency light-emitting device, which is therefore preferred. Specifically, the acidity coefficient pKa of the first organic compound is preferably 8 or more, more preferably 10 or more, and even more preferably 12 or more.

[0174] Specific examples of electron-donating groups include alkyl, alkoxy, aryloxy, alkylamino, arylamino, and heterocyclic amino groups. However, the preferred electron-donating group introduced onto the phenanthroline ring is not limited to these. Any group that can increase the electron density of the phenanthroline ring can be used as an electron-donating group. Furthermore, the electron-donating group can also be introduced into the phenanthroline ring via an arylene group such as a p-phenylene group, which is preferably para-phenylene.

[0175] Alkyl groups represent hydrocarbons (C14- ... n H 2n+2 A monovalent group that removes one hydrogen atom. Specific examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, isopentyl, sec-pentyl, tert-pentyl, neopentyl, hexyl, isohexyl, sec-hexyl, tert-hexyl, neohexyl, 3-methylpentyl, 2-methylpentyl, 2-ethylbutyl, 1,2-dimethylbutyl, 2,3-dimethylbutyl, etc.

[0176] An alkoxy group is a monovalent group having an alkyl group bonded to an oxygen atom. Specific examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, n-pentoxy, isopentoxy, sec-pentoxy, tert-pentoxy, neopentoxy, n-hexoxy, isohexoxy, sec-hexoxy, tert-hexoxy, and neohexoxy.

[0177] An aryloxy group represents a monovalent group having an aryl group bonded to an oxygen atom. An aryl group represents a monovalent group formed by removing a hydrogen atom from one of the carbon atoms in a monocyclic or polycyclic aromatic compound. Specific examples of aryloxy groups include phenoxy, o-tolyloxy, m-tolyloxy, p-tolyloxy, mesityleneoxy, o-biphenyloxy, m-biphenyloxy, p-biphenyloxy, 1-naphthyloxy, 2-naphthyloxy, and 2-fluorenyloxy. Aryloxy groups can also have substituents; specific examples of such substituents include alkyl, alkoxy, and phenyl groups.

[0178] Alkylamino refers to a primary or secondary amine in which a hydrogen atom has been removed from the nitrogen atom by one or two alkyl groups bonded to the nitrogen atom. Specific examples of alkylamino include dimethylamino, diethylamino, etc.

[0179] Arylamino groups are monovalent groups formed by removing a hydrogen atom from the nitrogen atom of a primary or secondary amine, which has one or two aryl groups bonded to the nitrogen atom. Specific examples of arylamino groups include diphenylamino, bis(α-naphthyl)amino, and bis(m-tolyl)amino. Arylamino groups can also have substituents, and specific examples of such substituents include alkyl, alkoxy, and phenyl groups.

[0180] Furthermore, an amino group having both alkyl and aryl groups bonded to a nitrogen atom can be classified as either an alkylamino group or an arylamino group. Specific examples of such an amino group include N-methyl-N-phenylamino.

[0181] A heterocyclic amino group represents a monovalent group in which a hydrogen atom has been removed from a nitrogen atom in the cyclic atom of a heterocyclic amine. Note that here, heterocyclic amines refer to monocyclic or polycyclic heterocyclic compounds, and indicate compounds in which at least one nitrogen atom in the cyclic atom is bonded with a hydrogen atom. Specific examples of heterocyclic amino groups include those represented by the following structural formulas (R-1) to (R-26). Note that heterocyclic amino groups may also have substituents; specific examples of such substituents include alkyl, alkoxy, and phenyl groups.

[0182] [Chemical Formula 1]

[0183]

[0184] Note that when the heterocyclic amino group is aromatic and the non-shared electron pair of the nitrogen atom contributes to the aromaticity, the electron-donating ability of the phenanthrene ring is sometimes reduced compared to the case where the non-shared electron pair of the nitrogen atom does not contribute to the aromaticity. Therefore, among the aforementioned heterocyclic amino groups, it is more preferable to use heterocyclic amino groups where the non-shared electron pair of the nitrogen atom does not contribute to the aromaticity. Specifically, groups represented by structural formulas (R-1), (R-2), (R-3), (R-4), (R-5), (R-8), (R-9), (R-10), (R-12), (R-14), (R-15), (R-16), (R-17), or (R-21) are more preferably electron-donating groups. Among these, groups represented by structural formulas (R-3), (R-4), (R-8), or (R-21) have high electron-donating ability and can further increase the electron density of the phenanthrene ring, and are therefore preferred.

[0185] In addition, as specific examples of electron-donating groups, groups represented by the following structural formulas (R-27) and (R-28) can be cited.

[0186] [Chemical Formula 2]

[0187]

[0188] Note that organic compounds containing a phenanthroline ring, which can be used as the first organic compound, can also have both the aforementioned electron-donating group and other substituents. Note that when an electron-withdrawing group (cyano, fluorine, etc.) is introduced into the phenanthroline ring, the electron density of the phenanthroline ring may decrease, making it less likely to interact with the metal, and therefore this is not preferred. Specific examples of substituents other than the aforementioned electron-donating group that can be introduced into the phenanthroline ring include aryl groups. Specific examples of aryl groups include phenyl, o-tolyl, m-tolyl, p-tolyl, mesitylene, o-biphenyl, m-biphenyl, p-biphenyl, 1-naphthyl, 2-naphthyl, 2-fluorenyl, etc. Aryl groups can also have substituents; specific examples of such substituents include alkyl, alkoxy, phenyl, etc.

[0189] Alternatively, the first organic compound may also have a structure in which multiple phenanthroline rings are linked by single bonds or by divalent groups. Specific examples of divalent groups include alkylene groups, arylene groups, etc.

[0190] An alkylene group is a divalent group formed by removing two hydrogen atoms from an alkane. Specific examples of alkylene groups include divalent groups that also have a structure formed by removing one hydrogen atom from the aforementioned alkyl groups.

[0191] An arylene is a divalent group formed by removing two hydrogen atoms from an aromatic hydrocarbon. As a specific example, a divalent group can be described that further removes one hydrogen atom from the aforementioned aryl group. Arylene groups can also have substituents; specific examples of such substituents include alkyl, alkoxy, and phenyl groups.

[0192] Structural formulas (100) to (109) show specific examples of organic compounds having a phenanthrene ring that can be used as a first organic compound. Note that the organic compounds that can be used as a first organic compound are not limited thereto. The structural formula (100) is 4,7-di-1-pyrrolidinyl-1,10-phenanthroline (abbreviation: Pyrrd-Phen), the structural formula (101) is 4,7-bis[4-(1-pyrrolidinyl)phenyl]-1,10-phenanthroline (abbreviation: PrdP2Phen), the structural formula (103) is 4,7-dimethoxy-1,10-phenanthroline (abbreviation: p-MeO-Phen), the structural formula (104) is 4,7-bis(1,3,4,6,7,8-hexahydro-2H-pyrimidino[1,2-a]pyrimidin-1-yl)-1,10-phenanthroline (abbreviation: 4,7hpp2Phen), and the structural formula (106) is 2,2'-(1,3-phenylene)bis[9-(1,3,4,6,7,8-hexahydro-2H-pyrimidino[1,2-a]pyrimidin-1-yl)-1,10-phenanthroline (abbreviation: 4,7hpp2Phen). [1,2-a]pyrimidin-1-yl)-1,10-phenanthroline] (abbreviation: mhppPhen2P), structural formula (107) is 2-(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidin-1-yl)-9-phenyl-1,10-phenanthroline (abbreviation: 9Ph-2hppPhen), structural formula (108) is 2,9-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidin-1-yl)-1,10-phenanthroline (abbreviation: 2,9hpp2Phen), structural formula (109) is 4,7-bis(2,3,3a,4,5,6,7,7a-octahydro-1H-isoindol-2-yl)-1,10-phenanthroline (abbreviation: Hid2Phen).

[0193] [Chemical Formula 3]

[0194]

[0195] <<Estimating Properties Using Quantum Chemical Calculations>>

[0196] The minimum electrostatic potential (ESP) of organic compounds represented by structural formulas (100) to (109) was estimated using quantum chemical calculations. Similarly, the minimum ESPs of 4,7-diphenyl-1,10-phenanthroline (abbreviated as BPhen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBPhen), and 1,10-phenanthroline (abbreviated as Phen) were also estimated for comparison. The structural formulas of BPhen, mPPhen2P, NBPhen, and Phen are shown below.

[0197] [Chemical Formula 4]

[0198]

[0199] Gaussian09 was used as the quantum chemical calculation program. The calculations were performed using an SGI8600 from HPE. The ground-state most stable structures of each organic compound were calculated using density functional theory (DFT). 6-311G(d,p) was used as the basis function, and B3LYP was used as the functional.

[0200] The following shows the estimated minimum ESP values ​​of various organic compounds obtained through analysis of their ground-state electrostatic potentials. Electrostatic potential refers to the interaction energy between a positive point charge of unit charge and the electron distribution of a molecule. Furthermore, the value of the electrostatic potential varies depending on the threshold of the electron density. The following shows the threshold for electron density distribution set at 0.0004e / a0 in the atomic unit system. 3 Or 0.003e / a0 3 The electrostatic potential of the electron density distribution at time t. Note that in the table, the threshold for the electron density distribution is denoted as the density threshold.

[0201] [Table 4]

[0202]

[0203] As shown in the table above, the threshold for electron density distribution in the organic compounds represented by structural formulas (100) to (104) and (109) is 0.0004e / a0. 3 The minimum value of ESP is -0.085E. h Therefore, it is most suitable to use it as the first organic compound. On the other hand, it is known that the minimum ESP of the organic compounds represented by structural formulas (105) to (108) is greater than -0.085E. h .

[0204] It can be seen that the organic compounds represented by structural formulas (100) to (104) and (109) are organic compounds with electron-donating groups at the 4 and 7 positions of the 1,10-phenanthroline ring, and therefore have the most preferred values.

[0205] The organic compound represented by structural formula (105) is an organic compound with electron-donating groups at the 4 and 7 positions of the 1,10-phenanthroline ring, but the N-carbazole group is used as the electron-donating group. In the N-carbazole group, the non-shared electron pair of the nitrogen atom contributes to aromaticity, so compared with groups where the non-shared electron pair of the nitrogen atom does not contribute to aromaticity, the electron-donating property of the phenanthroline ring is reduced, and therefore the minimum value of ESP does not easily decrease, thus yielding the above results.

[0206] The organic compounds represented by structural formulas (106) to (108) are organic compounds having electron-donating groups at positions 2 and 9 of the 1,10-phenanthroline ring. Compared to the case where electron-donating groups are introduced at positions 4 and 7 of the 1,10-phenanthroline ring, the electron-donating properties of the nitrogen atoms at positions 1 and 10 of the 1,10-phenanthroline ring are lower when electron-donating groups are introduced at positions 2 and 9 of the 1,10-phenanthroline ring. Therefore, the substitution positions of the electron-donating groups in the 1,10-phenanthroline ring are preferably positions 4 and 7.

[0207] Note that the LUMO energy level of the second organic compound is more preferably lower than that of the first organic compound. This allows for easy donation of electrons from the donor level formed by the first organic compound and the metal to the second organic compound. Furthermore, the second organic compound preferably possesses electron transport properties, and therefore its LUMO energy level is preferably lower than that of the first organic compound.

[0208] For example, the LUMO energy level of the first organic compound is preferably -3.0 eV or higher and -2.0 eV or lower, more preferably -2.7 eV or higher and -2.0 eV or lower. Furthermore, the LUMO energy level of the second organic compound is preferably -3.0 eV or higher and -2.0 eV or lower, more preferably -3.0 eV or higher and -2.5 eV or lower. This allows for easy electron supply from the donor level formed by the first organic compound and the metal to the second organic compound. Additionally, this improves the electron transport properties of the second organic compound.

[0209] Note that the HOMO and LUMO energy levels of organic compounds are generally estimated using cyclic voltammetry (CV), photoelectron spectroscopy, optical absorption spectroscopy, and inverse photoelectron spectroscopy. When comparing values ​​of different compounds, it is preferable to use values ​​estimated through the same measurements.

[0210] In addition, when the acidity coefficient pKa of an organic compound is unknown, the acidity coefficient pKa of each skeleton of the organic compound can be investigated, and the largest acidity coefficient pKa can be regarded as the acidity coefficient pKa of the organic compound.

[0211] Alternatively, the acidity coefficient can be calculated. For example, the acidity coefficient pKa can be calculated using the following method.

[0212] The initial molecular structures of each molecule used in the computational model are the most stable structures (single ground state) obtained through first-principles calculations.

[0213] For the aforementioned first-principles calculations, the most stable structure in the singlet ground state was calculated using Jaguar, a quantum chemistry calculation software manufactured by Schrödinger, Inc., via density functional theory (DFT). 6-31G** was used as the basis function, and B3LYP-D3 was used as the functional. The structure used for the quantum chemistry calculations was sampled using Maestro GUI, also manufactured by Schrödinger, Inc., with conformational analysis performed using mixed torsional / low-mode sampling.

[0214] In pKa calculations, more than one atom in each molecule is designated as a basic position. The Macro Model is used to explore the stable structure of the protonated molecule in water, and the lowest-energy conformational isomers obtained through conformational exploration using the OPLS2005 force field are used. The structure is optimized using B3LYP / 6-31G* in Jaguar's pKa calculation module, followed by single-point calculations using cc-pVTZ(+), and pKa values ​​are calculated using empirical corrections for functional groups. For molecules where more than one atom is designated as a basic position, the largest value among the results is used as the pKa value. The obtained pKa values ​​are shown.

[0215] The acidity coefficient pKa of 2,9hpp2Phen (structural formula (108)) is 13.35, the acidity coefficient pKa of 4,7hpp2Phen (structural formula (104)) is 13.42, the acidity coefficient pKa of Pyrrd-Phen (structural formula (100)) is 11.23, the acidity coefficient pKa of mPPhen2P is 5.16, the acidity coefficient pKa of NBPhen is 5.59, and the acidity coefficient pKa of BPhen is 5.62.

[0216] <Second Organic Compound>

[0217] As the second organic compound, an organic compound with electron transport properties can be used. Preferably, the organic compound with electron transport properties has an electron mobility of 1×10⁻⁶ when the square root of the electric field strength [V / cm] is 600. - 7 cm 2 For substances with an electron mobility of 1×10⁶ / Vs or higher, it is preferable to use a substance with an electron mobility of 1×10⁶ / Vs. -6 cm 2 Substances with a value of / Vs or higher. Additionally, any substance other than those mentioned above can be used as long as its electron transport capability is higher than its hole transport capability.

[0218] As an organic compound with electron transport capabilities, an organic compound containing a π-electron-deficient heteroaromatic ring is preferred. For example, one or more of the following are preferred: organic compounds containing a heteroaromatic ring with an azole skeleton, organic compounds containing a heteroaromatic ring with a pyridine skeleton, organic compounds containing a heteroaromatic ring with a diazine skeleton, and organic compounds containing a heteroaromatic ring with a triazine skeleton.

[0219] As organic compounds with electron transport capabilities, examples include: 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]phenyl (abbreviated as OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as CO11), and 2,2',2''-(1,3,5-phenyltriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as TPB). I), 2-[3-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs) and other organic compounds with azole skeletons; 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), 4,7-diphenyl-1,10-phenanthroline (abbreviation: BPhen), copper hydroxide (abbreviation: BCP), 2,9-di(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: Organic compounds including heteroaromatic rings with a pyridine skeleton, such as NBPhen, 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P); 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTPDBq-II), 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mCzBPDBq), 2-[4'-(9-phenyl- ... [Azol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II) and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furano[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3'-(dibenzothiophene-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furano[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophene-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole-9-yl) 4,6mCzBP2Pm, 8-(biphenyl-4-yl)-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-bis[3-(dibenzothiophene-4-yl)phenyl]benzofurano[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furano[3,2- d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphthyl)-6-yl]-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2'-(pyridin-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(pyridin-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2- Phenylacetidine (abbreviated as: 6mBP-4Cz2PPm), 2,6-bis(4-naphthyl-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviated as: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviated as: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviated as: PC-cgDBCzQz), and other organic compounds with a diazine skeleton; 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobis[9H-fluorene]-2-yl)-1,3,5-Triazine (abbreviation: BP-SFTzn), 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), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPT) zn), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indo[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(dibenzothiophene-4- [3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenylindolo[2,3-a]carbazole (abbreviation: B) Organic compounds with triazine skeletons include P-Icz(II)Tzn), 2-[3'-(triphenyl-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviated as: mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviated as: PCDBfTzn), and 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',1''-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviated as: mBP-TPDBfTzn).

[0220] Among these, organic compounds containing phenanthrene-rhein rings, such as BPhen, BCP, NBPhen, and mPPhen2P, especially those containing a 1,10-phenanthrene-rhein ring, are preferred because the two nitrogen atoms can coordinate with a metal, thus readily interacting with it. Furthermore, organic compounds with phenanthrene-rhein ring dimer structures, such as mPPhen2P, exhibit excellent stability, making them even more preferred.

[0221] Furthermore, the second organic compound preferably has 25 or more and 100 or less carbon atoms. Using this number of carbon atoms allows for the production of organic compounds with good sublimation properties, thereby suppressing the thermal decomposition of organic compounds during vacuum evaporation and resulting in good material utilization efficiency. Additionally, T can be used... g The organic compound is heated to temperatures above 100°C. Therefore, an electron-injection layer 115 that is not easily crystallized can be achieved. Thus, a layer that is not easily crystallized even when subjected to atmospheric oxygen or water, or chemical solutions or water during the process, while processing a portion of the organic compound layer using lithography can be achieved. Therefore, the increase in driving voltage or decrease in current efficiency of the light-emitting device due to crystallization of the electron-injection layer 115 can be prevented. Therefore, by using T... g Using an organic compound with a temperature above 100°C as the second organic compound, the composite material containing the metal, the first organic compound, and the second organic compound can be used as the electron injection layer 115 of a light-emitting device in which a portion of the organic compound layer is processed using lithography.

[0222] As an organic compound including a phenanthroline ring and having a temperature above 100°C g Organic compounds, such as NBPhen (T g :165℃), mPPhen2P (T g : 135℃), 2,2'-(biphenyl-4,4'-diyl)bis(9-phenyl-1,10-phenanthroline) (abbreviation: PPhen2BP) (T g : 166℃), 2,2'-biphenyl-3,3'-dimethylbis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2BP) (T g :144℃), 2,8-bis(phenanthroline-5-yl)dibenzofuran (abbreviation: 2,8Phen2DBf) (T g : 210℃), 5,5',5''-(benzene-1,3,5-triyl)tri-1,10-phenanthroline (abbreviation: Phen3P) (T gFor example, the glass transition temperature (T257) can be measured using a differential scanning calorimeter (DSC8500 manufactured by PerkinElmer Japan Co., Ltd.), where the powder is placed on an aluminum unit and heated at a rate of 40°C / min. g ).

[0223] Furthermore, an organic compound with an acidity coefficient pKa of 4 or higher and less than 8 can be used as the second organic compound. This reduces the hole transport properties of the second organic compound, thereby reducing the hole transport properties of the electron injection layer 115 and preventing holes from transporting from the electron injection layer 115 to the second electrode 102. This results in a highly efficient light-emitting device, which is preferred. However, when the acidity coefficient pKa is too high, the solubility in water increases, which sometimes reduces the resistance to water and chemicals used in lithography processes. Therefore, the acidity coefficient pKa of the second organic compound is preferably 4 or higher and less than 8.

[0224] In layers containing a combination of a metal, a first organic compound, and a second organic compound, the materials interact more efficiently than in layers containing only two of these materials (e.g., a layer containing a metal and a first organic compound, or a layer containing a metal and a second organic compound). This phenomenon was confirmed by fabricating films containing these materials using metals belonging to the odd-numbered group and measuring the spin density of the films using electron spin resonance (ESR).

[0225] For example, when the spin density of a film containing a metal, a first organic compound, and a second organic compound, as measured by ESR, is higher than that of a film containing a metal and a first organic compound, or a film containing a metal and a second organic compound, as measured by ESR, it can be confirmed that the materials interact more efficiently in a film containing a combination of a metal, a first organic compound, and a second organic compound compared to a film containing only two of the aforementioned materials. Furthermore, it is preferable to perform the spin density measurement using electron spin resonance at room temperature.

[0226] More specifically, the film containing the metal and the first organic compound, for example, arises from a spin density of 2 × 10⁻⁶, a signal observed using electron spin resonance at a g value of around 2.00. 16 spins / cm 3 The following describes a mixed film containing a metal and a second organic compound, for example, arising from a signal with a spin density of 2 × 10⁻⁶ observed near a g value of 2.00 using electron spin resonance. 16 spins / cm 3The mixed film comprising the first organic compound and the second organic compound, for example, arises from a signal with a spin density of 2 × 10⁻⁶ observed near a g value of 2.00 using electron spin resonance. 16 spins / cm 3 The following describes a mixed film comprising a metal, a first organic compound, and a second organic compound, for example, arising from a signal with a spin density of 5 × 10⁻⁶ observed near a g value of 2.00 using electron spin resonance. 16 spins / cm 3 The above is preferred to be 1×10 17 spins / cm 3 Therefore, it can be confirmed that the materials interact more efficiently in a mixed film containing a combination of a metal, a first organic compound, and a second organic compound compared to a mixed film containing only two of the aforementioned materials.

[0227] Furthermore, the metal ratio is preferably 0.1 or more and 10 or less of the molar ratio of the sum of the first organic compound and the second organic compound, more preferably 0.2 or more and 5 or less, and even more preferably 0.5 or more and 2 or less. Alternatively, the volume ratio is preferably 0.01 or more and 0.3 or less, more preferably 0.02 or more and 0.2 or less, and even more preferably 0.05 or more and 0.1 or less. By mixing the metal, the first organic compound, and the second organic compound in this ratio, an electron injection layer with good electron injection properties can be provided. Additionally, the first organic compound is preferably 0.1 or more and 10 or less of the volume ratio of the second organic compound, more preferably 0.2 or more and 5 or less, and even more preferably 0.5 or more and 2 or less. By mixing the first organic compound and the second organic compound in this ratio, an electron injection layer with good electron transport properties can be provided.

[0228] Furthermore, the thickness of the electron injection layer 115 is preferably 3 nm or more and 20 nm, more preferably 5 nm or more and 10 nm or less. Thus, the composite material formed by the mixture of metal, the first organic compound, and the second organic compound can function well, thereby providing a light-emitting device exhibiting high luminous efficiency.

[0229] The structure shown in this embodiment can be appropriately combined with the structures shown in other embodiments.

[0230] (Implementation Method 2)

[0231] In this embodiment, other structures of the light-emitting device according to one aspect of the present invention are described.

[0232] Figure 6AThe light-emitting device 130 is shown as an example of a light-emitting device according to one aspect of the present invention. The light-emitting device 130 is a light-emitting device comprising an organic compound layer 103 having a light-emitting layer 113 between a first electrode 101 having an anode and a second electrode 102 having a cathode.

[0233] Figure 6B Light-emitting device 130 is shown as another example of a light-emitting device according to one aspect of the present invention. Light-emitting device 130 is a series-connected light-emitting device. In light-emitting device 130, the organic compound layer 103 includes a first light-emitting unit 501 having a first light-emitting layer 113_1, a second light-emitting unit 502 having a second light-emitting layer 113_2, and an intermediate layer 160.

[0234] Note that in this embodiment, a light-emitting device including an intermediate layer 160 and two light-emitting units is used as an example. However, a light-emitting device including an intermediate layer of n (n is an integer greater than 1) and light-emitting units of n+1 layers can also be used.

[0235] For example, Figure 6C The illustrated light-emitting device 130 is an example of a series-connected light-emitting device, where n is 2, and the organic compound layer 103 includes a first light-emitting unit 501 having a first light-emitting layer 113_1, a first intermediate layer 160_1, a second light-emitting unit 502 having a second light-emitting layer 113_2, a second intermediate layer 160_2, and a third light-emitting unit 503 having a third light-emitting layer 113_3. The color gamut of the light emitted by the light-emitting layers in each light-emitting unit can be the same or different. Furthermore, the light-emitting layer can have a single-layer structure or a multilayer structure. For example, by making the light-emitting layers in the first and third light-emitting units emit light in the blue region and the multilayer light-emitting layer in the second light-emitting unit emit light in the red and green regions, white light can be obtained.

[0236] For example, Figure 6DThe illustrated light-emitting device 130 is an example of a series-connected light-emitting device, where n is 3, and the organic compound layer 103 includes a first light-emitting unit 501 having a first light-emitting layer 113_1, a first intermediate layer 160_1, a second light-emitting unit 502 having a second light-emitting layer 113_2, a second intermediate layer 160_2, a third light-emitting unit 503 having a third light-emitting layer 113_3, a third intermediate layer 160_3, and a fourth light-emitting unit 504 having a fourth light-emitting layer 113_4. The color gamut of the light emitted by the light-emitting layers in each light-emitting unit can be the same or different. In addition, the light-emitting layer can have a single-layer structure or a stacked structure. For example, the four light-emitting units can adopt the following structures: a structure in which any three are blue (B) and the remaining one is green (G); a structure in which any two are blue (B) and the remaining two are yellow (Y); and a structure in which any one is red (R), the other is green (G), and the remaining two are blue (B), etc.

[0237] The light-emitting device 130 may also be a light-emitting device manufactured by lithography. When using a light-emitting device manufactured by lithography, at least the light-emitting layer 113 or the second light-emitting layer 113_2 and the organic compound layer closer to the first electrode 101 than the aforementioned layers are processed simultaneously, so that the ends of these layers are roughly aligned in the vertical direction.

[0238] In addition, the organic compound layer 103 may also include other functional layers besides the light-emitting layer. Figure 6A The structure is shown below: In addition to the light-emitting layer 113, the organic compound layer 103 also includes a hole injection layer 111, a hole transport layer 112, an electron transport layer 114, and an electron injection layer 115. Furthermore, the first light-emitting unit 501 and the second light-emitting unit 502 may also include other functional layers besides the light-emitting layer. Figure 6B The following structure is shown: The first light-emitting unit 501, in addition to the first light-emitting layer 113_1, also has a hole injection layer 111, a first hole transport layer 112_1, and a first electron transport layer 114_1. The second light-emitting unit 502, in addition to the second light-emitting layer 113_2, also has a second hole transport layer 112_2, a second electron transport layer 114_2, and an electron injection layer 115. Note that the structure of the organic compound layer 103 in this invention is not limited to this; it may omit any of the above layers or include other layers. Typical examples of other layers include carrier blocking layers (hole blocking layers, electron blocking layers), exciton blocking layers, etc.

[0239] <<Structure of the Intermediate Layer>>

[0240] First, the materials that can be used for the intermediate layer 160 will be described. The intermediate layer 160 preferably has the same structure as the electron injection layer described in Embodiment 1. More preferably, the intermediate layer 160 has a stacked structure including a first layer 161 and a second layer 162, wherein the first layer 161 preferably has the same structure as the electron injection layer described in Embodiment 1. By employing the above structure, an intermediate layer resistant to oxygen or water in the atmosphere during lithography processing, and chemical solutions or water in the process, can be formed.

[0241] Furthermore, the second layer 162 is closer to the second electrode 102 than the first layer 161. Alternatively, a third layer 163 may be provided between the first layer 161 and the second layer 162 to facilitate electron transfer between the two layers.

[0242] Furthermore, since the intermediate layer 160 includes a first layer 161, this first layer 161 functions as an electron injection layer in the light-emitting unit on the anode side. Therefore, the light-emitting unit on the anode side ( Figure 6B The first light-emitting unit 501 in the process may or may not have an electron injection layer. Similarly, since the intermediate layer 160 includes a second layer 162, this second layer 162 functions as a hole injection layer in the light-emitting unit on the cathode side. Therefore, the light-emitting unit on the cathode side ( Figure 6B The second light-emitting unit 502 in the middle may or may not have a hole injection layer.

[0243] Furthermore, when the first layer 161 is not easily affected by oxygen, water, chemicals, etc., for example, when the light-emitting device of one aspect of the present invention is manufactured by a method that does not involve processing an organic compound layer using lithography, a donor material can also be used in the first layer 161. Specific examples of donor materials include alkali metals or alkali metal compounds. Specific examples of alkali metals include lithium, sodium, potassium, rubidium, cesium, francium, etc. Specific examples of alkali metal compounds include compounds of the aforementioned alkali metals, such as lithium compounds like lithium oxide.

[0244] As an alkali metal or alkali metal compound, lithium or lithium compounds mentioned above are preferred. Specifically, lithium, lithium complexes, lithium compounds, and lithium alloys can be used. Examples include lithium complexes containing alkyl groups such as lithium, lithium oxide, lithium nitride, lithium carbonate, lithium fluoride, 8-hydroxyquinoline-lithium (Liq), and 2-methyl-8-hydroxyquinoline-lithium (Li-mq).

[0245] Furthermore, when an alkali metal or alkali metal compound is used as the first layer 161, an organic compound with electron transport properties may also be included in addition to the alkali metal or alkali metal compound. In this case, an organic compound with electron transport properties that can be used in the electron injection layer described in Embodiment 1 can be used as the organic compound with electron transport properties.

[0246] The second layer is preferably a layer containing a third organic compound and a fourth organic compound (details of which will be described later). This allows for effective hole injection into the upper light-emitting layer, making it a preferred choice.

[0247] <Third Organic Compound>

[0248] The third organic compound is preferably an organic compound with hole-transporting properties. Various organic compounds can be used as hole-transporting organic compounds, such as aromatic amines, heteroaromatic compounds, aromatic hydrocarbons, and polymers (oligomers, dendritic polymers, polymers, etc.). Preferably, the organic compound with a hole mobility of 1×10⁻⁶ is used. -6 cm 2 Organic compounds with a density of / Vs or higher. Organic compounds with hole-transporting properties are preferably compounds comprising fused aromatic rings or π-electron-rich heteroaromatic rings. As fused aromatic rings, anthracene rings, naphthalene rings, etc., are preferred. Furthermore, as π-electron-rich heteroaromatic rings, fused aromatic rings having at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton are preferred; specifically, carbazole rings, dibenzothiophene rings, or rings fused with these rings to aromatic rings or heteroaromatic rings are preferred. Note that in this specification, etc., organic compounds with hole-transporting properties are sometimes referred to as materials with hole-transporting properties.

[0249] Such hole-transporting organic compounds are more preferably those having a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, or an anthracene skeleton. In particular, they can be aromatic amines having substituents including a dibenzofuran ring or a dibenzothiophene ring, aromatic monoamines including a naphthyl ring, or aromatic monoamines in which a 9-fluorene group is bonded to the nitrogen of the amine via an arylene group. Note that when these hole-transporting organic compounds are substances including N,N-bis(4-biphenyl)amino groups, long-lifetime light-emitting devices can be manufactured, and therefore they are preferred.

[0250] As examples of the aforementioned hole-transporting organic compounds, specific examples include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviated as: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviated as: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviated as: BBABnf(6)), and N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviated as: BBABnf(6)). -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-benzidine (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'-binathyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binathyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binathyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binathyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binathyl-1 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenyl)-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'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tri(biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirodi[9H-fluorene]-2-amine (abbreviation: PCBN) BSF), N,N-bis(biphenyl-4-yl)-9,9'-spirodi[9H-fluorene]-2-amine (abbreviated as: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirodi[9H-fluorene]-4-amine (abbreviated as: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi[9H-fluorene]-4-amine (abbreviated as: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)dibenzofuran-4-amine (abbreviated as: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine ( Abbreviations: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluorene-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluorene-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[9-phenyl-9H-carbazole-3-yl] ... The following are listed as abbreviations: PCBANB, 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as PCBABB), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirodi[9H-fluorene]-2-amine (abbreviated as PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as PCBiF), N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-4-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-3-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-2-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirodi-9H-fluorene-1-amine, etc.

[0251] In addition, as organic compounds with hole transport capabilities, the following aromatic amine compounds can be used: N,N'-bis(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviated as DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviated as DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviated as DPA3B), etc.

[0252] <The Fourth Organic Compound>

[0253] The fourth organic compound is preferably a substance that is acceptor of the third organic compound. As an acceptor substance, an organic compound having an electron-withdrawing group (halogen group, cyano group, etc.) is preferred, and an organic compound having at least one of a halogen group and a cyano group is more preferred, wherein the number of halogen groups and cyano groups is 4 or more. Specific examples include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethylethane (F4-TCNQ), chloroquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinone dimethylethane (F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malonitrile. In particular, compounds such as HAT-CN, in which electron-withdrawing groups are bonded to fused aromatic rings with multiple heteroatoms, are thermally stable and therefore preferred. In addition, electron-withdrawing groups (especially halogen groups such as fluorine groups, cyano groups, etc.)[3] axylene derivatives are preferred because they have very high electron acceptor properties. Specifically, examples include: α,α',α''-1,2,3-cyclopropanetrimethylenetri[4-cyano-2,3,5,6-tetrafluorophenylacetonitrile], α,α',α''-1,2,3-cyclopropanetrimethylenetri[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)phenylacetonitrile], α,α',α''-1,2,3-cyclopropanetrimethylenetri[2,3,4,5,6-pentafluorophenylacetonitrile], etc. In addition to the organic compounds mentioned above, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used as substances with acceptor properties.

[0254] In the second layer, signals observed via electron spin resonance are preferred. For example, the spin density of a signal observed near a g value of 2.00 is preferably 1 × 10⁻⁶. 17 spins / cm 3 The above is preferred to be 1×10 18 spins / cm 3 The above is further preferred to be 1×10 19 spins / cm 3 Therefore, the second layer can be used as a charge generation layer. Furthermore, it allows for the fabrication of light-emitting devices with low driving voltage and high efficiency.

[0255] In addition, a third layer can be provided between the first and second intermediate layers to facilitate the smooth transfer of electrons between the two layers.

[0256] The third layer contains an electron-transporting material and is able to prevent the interaction between the first and second layers to facilitate electron transfer. The LUMO energy level of the electron-transporting material contained in the third layer 163 is preferably the LUMO energy level of the acceptor material in the second layer 162, which is in contact with the intermediate layer 160 in the light-emitting unit on the side of the first electrode 101. Figure 6B The energy levels between the LUMO energy levels of the organic compound contained in the first electron transport layer 114_1 of the first light-emitting unit 501. Specifically, the LUMO energy level of the electron-transporting material used in the third layer 163 is -5.0 eV or higher, preferably -5.0 eV or higher and -3.0 eV or lower, more preferably -4.30 eV or higher and -3.00 eV or lower, and even more preferably -4.30 eV or higher and -3.30 eV or lower. At this time, electrons generated in the second layer 162 can be easily injected into the first layer 161, thus suppressing the rise of the driving voltage of the light-emitting device, which is preferred. In addition, as the electron-transporting material used in the third layer 163, phthalocyanine materials or metal complexes having metal-oxygen bonds and aromatic ligands are preferred.

[0257] Specifically, perylene tetracarboxylic acid derivatives such as diquinoxolino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA), 2,3,8,9,14,15-hexafluorodiquinoxolino[2,3-a:2',3'-c]phenazine (abbreviated as HATNA-F6), 3,4,9,10-perylene tetracarboxylic acid diimide (abbreviated as PTCDI), 3,4,9,10-perylene tetracarboxylic acid-bis-benzimidazole (abbreviated as PTCBI), (C60-Ih)[5,6]fullerene (abbreviated as C60), (C70-D5h)[5,6]fullerene (abbreviated as C70), and phthalocyanine (abbreviated as H2Pc) can be used. Alternatively, metal phthalocyanines containing copper, zinc, cobalt, chromium, nickel, etc., and their derivatives, such as copper phthalocyanine (CuPc), zinc phthalocyanine (ZnPc), cobalt phthalocyanine (CoPc), iron phthalocyanine (FePc), tin phthalocyanine (SnPc), tin phthalocyanine (SnOPc), titanium phthalocyanine (TiOPc), and vanadium phthalocyanine (VOPc), can be used. In particular, phthalocyanine metal complexes such as copper phthalocyanine or zinc phthalocyanine, or 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine, are preferred.

[0258] In addition, the thickness of the third layer 163 is preferably 1 nm or more and 10 nm or less, more preferably 2 nm or more and 5 nm or less.

[0259] Next, the structure other than the intermediate layer 160 of the light-emitting device 130 will be described.

[0260] <<Structure of the First Electrode>>

[0261] The first electrode 101 is an electrode having an anode. The first electrode 101 may also have a multilayer structure, in which case the layer in contact with the organic compound layer 103 is used as the anode. The anode is preferably formed using a metal, alloy, conductive compound, or mixture thereof with a high work function (specifically 4.0 eV or higher). Specifically, examples include indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide, indium zinc oxide, and indium tin oxide (IWZO) containing tungsten oxide and zinc oxide. While these conductive metal oxide films are typically deposited by sputtering, they can also be formed using sol-gel methods. As an example of a formation method, an indium zinc oxide formation method using a target with 1 wt% to 20 wt% zinc oxide added to indium oxide can be used by sputtering. Alternatively, indium oxide (IWZO) containing tungsten oxide and zinc oxide can be formed by sputtering using a target containing 0.5 wt% to 5 wt% tungsten oxide and 0.1 wt% to 1 wt% zinc oxide. Other materials that can be used as the anode include, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), or nitrides of metallic materials (e.g., titanium nitride). Graphene can also be used as the anode material. Furthermore, by using the second layer 162 of the aforementioned intermediate layer 160 as the layer in contact with the anode (typically a hole injection layer), the work function can be disregarded when selecting the electrode material.

[0262] <<Structure of the Hole Injection Layer>>

[0263] Hole injection layer 111 is in contact with the anode and has the function of easily injecting holes into organic compound layer 103 (first light-emitting unit 501). Phthalocyanine compounds such as phthalocyanine (H2Pc), copper phthalocyanine (CuPc), etc.; aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (DNTPD), etc.; or polymers such as poly(3,4-ethylenedioxythiophene) / (polystyrene sulfonic acid) (PEDOT / PSS), etc., can be used to form hole injection layer 111.

[0264] Alternatively, the hole injection layer 111 can also be formed of a substance with electron acceptor properties. As an acceptor material, the substances described above as acceptor materials used in the second layer 162 of the intermediate layer 160 can also be used.

[0265] Alternatively, the hole injection layer 111 can also be formed using the organic compound containing hole transport material described above for the second layer 162 in the intermediate layer 160.

[0266] Note that when a mixture of an acceptor substance and a hole-transporting organic compound is used in the hole injection layer 111, the hole-transporting organic compound used in the mixture is more preferably a substance having a deep HOMO energy level of -5.7 eV or higher and -5.4 eV or lower. When the hole-transporting organic compound used in the mixture has a deep HOMO energy level, holes are easily injected into the hole transport layer, and a long-lifetime light-emitting device can be easily obtained. Furthermore, when the hole-transporting organic compound used in the mixture is a substance with a deep HOMO energy level, hole induction is appropriately suppressed, thus enabling a light-emitting device with an even longer lifetime.

[0267] By forming a hole injection layer 111, hole injection capability can be improved, thereby obtaining a light-emitting device with low driving voltage.

[0268] In addition, organic compounds with receptors can be easily deposited in substances with receptors using vapor deposition, making them easy-to-use materials.

[0269] In addition, since the second layer 162 in the intermediate layer 160 is used as a hole injection layer, the second light-emitting unit 502 does not have a hole injection layer, but the second light-emitting unit may also have a hole injection layer.

[0270] The hole transport layers (first hole transport layer 112_1, second hole transport layer 112_2) are formed by containing organic compounds with hole transport properties. The organic compounds with hole transport properties preferably have a concentration of 1 × 10⁻⁶. -6 cm 2 Hole mobility above / Vs.

[0271] Examples of materials exhibiting hole transport capabilities include: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (TPD), N,N'-bis(9,9'-spirobis[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (mBPAFLP), and 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (PCBA1BP). Compounds with aromatic amine skeletons include 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCCNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), and N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirodi[9H-fluorene]-2-amine (abbreviation: PCBASF);1,3-Bis(N-carbazolyl)benzene (mCP), 4,4'-bis(N-carbazolyl)biphenyl (CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H- 3,3'-Bicarbazole (abbreviated as mBPCCBP), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviated as βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviated as βNCCBP), 9,9'-bis-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviated as BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]- 3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole Compounds with a carbazole skeleton, such as 9-(2-naphthyl)-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviated as PCCzTp), 9,9'-bis(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenyl-2-yl)-3,3'-9H,9'H-bicarbazole, and 9-(triphenyl-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole;Compounds with a thiophene skeleton, such as 4,4',4''-(benzyl-1,3,5-triyl)tris(dibenzothiophene) (abbreviated as DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), and 4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV); and compounds with a furan skeleton, such as 4,4',4''-(benzyl-1,3,5-triyl)tris(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluorene-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Compounds with an aromatic amine backbone and compounds with a carbazole backbone are preferred due to their good reliability, high hole transport capacity, and ability to reduce driving voltage. Alternatively, organic compounds with hole transport capacity, which are also suitable as composite materials for the hole injection layer 111, can be used as materials constituting the hole transport layer.

[0272] <<Structure of the Emitting Layer>>

[0273] The light-emitting layers (light-emitting layer 113, first light-emitting layer 113_1, second light-emitting layer 113_2) preferably contain a light-emitting substance and a host material. Note that the light-emitting layers may also contain other materials. Alternatively, they may be two layers with different compositions.

[0274] The luminescent material can be a fluorescent luminescent material, a phosphorescent luminescent material, a material exhibiting thermally activated delayed fluorescence (TADF), or other luminescent materials.

[0275] In the luminescent layer, materials that can be used as fluorescent luminescent substances include, for example, the following substances. Note that other fluorescent luminescent substances can also be used.

[0276] Examples include 5,6-bis[4-(10-phenyl-9-anthrayl)phenyl]-2,2'-bipyridine (abbreviated as PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthrayl)biphenyl-4-yl]-2,2'-bipyridine (abbreviated as PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as 1,6mMemFLPAPrn), and 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-anthrayl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthrayl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthrayl)-4'-(9-phenyl-9- H-Carbazole-3-yl)triphenylamine (abbreviated as PCPAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis(N,N',N'-triphenyl-1,4-phenylenediamine) (abbreviated as DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-9H-carbazole-3-amine (abbreviated as 2PCAPPA), N-[4-(9,10-diphenyl-2-anthrayl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviated as 2DPAPPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p] 2,7,10,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9,10-diphenyl-2-anthrayl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthrayl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthrayl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), 9,10-bis(2-biphenyl)-2-(N,N',N'-triphenyl-1,4-phenylenediamine-N-yl)anthracene (abbreviation: 2DPABPhA), 9,10-Bis(biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenylbenzotetraphenyl (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]vinyl}-6-methyl-4H-pyran-4-yl)malonitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1-yl) ... H,5H-benzo[ij]quinazine-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCM2), N,N,N',N'-tetra(4-methylphenyl)tetraphenyl-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetra(4-methylphenyl)acenaphthene[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]quinazine-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCM2), CJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazin-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]vinyl}-4H-pyran-4-ylidene)malonium (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinazin-9-yl)vinyl]-4H-pyran-4-ylidene}malonium (abbreviation: Bi) sDCJTM), N,N'-diphenyl-N,N'-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), 3,10-bis[N-(9-phenyl-9H-carbazole-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. In particular, 1,6FLPAPrn, 1,6mMemFLPAPrn, 1,Fused aromatic diamine compounds, such as pyrene diamine compounds like 6BnfAPrn-03, exhibit good hole trapping properties and high luminescence efficiency or good reliability, making them preferred choices.

[0277] When phosphorescent materials are used as luminescent materials in the luminescent layer, the following materials can be cited as examples of usable materials.

[0278] Examples include organometallic iridium complexes with a 4H-triazole skeleton, such as tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviated as [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Mptz)3]), and tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(iPrptz-3b)3]); and tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazole]iridium(III) (abbreviated as [Ir... Organometallic iridium complexes with a 1H-triazole skeleton, such as [Ir(Prptz1-Me)3], tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Prptz1-Me)3]); organometallic iridium complexes with an imidazole skeleton, such as fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazolium]iridium(III) (abbreviated as [Ir(iPrpim)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviated as [Ir(dmpimpt-Me)3]); and bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2’ Iridium(III) tetra(1-pyrazolyl)borate (abbreviated as: FIr6), bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2’ Iridium(III) picolinate (FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinium-N,C 2’} Iridium(III)pyridinecarboxylate (abbreviated as: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridin-N,C 2’Organometallic iridium complexes such as iridium(III) acetylacetone (abbreviated as FIracac) with phenylpyridine derivatives having electron-withdrawing groups as ligands are emitted blue phosphorescence and have emission peaks in the wavelength region of 450 nm to 520 nm.

[0279] Additionally, examples include: tris(4-methyl-6-phenylpyrimidine)iridium(III) (abbreviated as [Ir(mppm)3]), tris(4-tert-butyl-6-phenylpyrimidine)iridium(III) (abbreviated as [Ir(tBuppm)3]), (acetylacetonate)bis(6-methyl-4-phenylpyrimidine)iridium(III) (abbreviated as [Ir(mppm)2(acac)]), (acetylacetonate)bis(6-tert-butyl-4-phenylpyrimidine)iridium(III) (abbreviated as [Ir(tBuppm)2(acac)]), (acetylacetonate)bis[6-(2-norborneol)-4-phenylpyrimidine]iridium(III) (abbreviated as [Ir(nbppm)2(acac)]), (acetylacetonate)bis[5-methyl Organometallic iridium complexes with a pyrimidine skeleton, such as 6-(2-methylphenyl)-4-phenylpyrimidinium-iridium(III) (abbreviated as [Ir(mpmppm)2(acac)]) and (acetylacetonium-ionium)bis(4,6-diphenylpyrimidinium-ionium(III)) (abbreviated as [Ir(dppm)2(acac)]); organometallic iridium complexes with a pyrazine skeleton, such as (acetylacetonium-ionium)bis(3,5-dimethyl-2-phenylpyrazine-ionium(III)) (abbreviated as [Ir(mppr-Me)2(acac)]) and (acetylacetonium-ionium)bis(5-isopropyl-3-methyl-2-phenylpyrazine-ionium(III)) (abbreviated as [Ir(mppr-iPr)2(acac)]); tris(2-phenylpyridinium-N,C 2’ Iridium (III) (abbreviated as: [Ir(ppy)3]), bis(2-phenylpyridinium-N,C) 2’ Iridium (III) acetylacetone (abbreviated as: [Ir(ppy)2(acac)]), bis(benzo[h]quinoline)iridium (III) acetylacetone (abbreviated as: [Ir(bzq)2(acac)]), tri(benzo[h]quinoline)iridium (III) (abbreviated as: [Ir(bzq)3]), tri(2-phenylquinoline-N,C 2’ Iridium (III) (abbreviated as: [Ir(pq)3]), bis(2-phenylquinoline-N,C) 2’Iridium (III) acetylacetone (abbreviation: [Ir(pq)2(acac)]), [2-d3-methyl-8-(2-pyridyl-κN)benzofurano[2,3-b]pyridin-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium (III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)), {2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofurano[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridinyl-κN]phenyl-κC}iridium (III) (abbreviation: Ir(5mtpy- Organometallic iridium complexes with a pyridine skeleton, such as [d6)2(mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridyl-κN)benzofurano[2,3-b]pyridin-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as: Ir(ppy)2(mbfpypy-d3)), [2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III) (abbreviated as: Ir(ppy)2(mdppy)), and rare earth metal complexes such as tri(acetylacetonate)(monophenanthroline)terbium(III) (abbreviated as: [Tb(acac)3(Phen)]), are included. These are primarily compounds exhibiting green phosphorescence and a emission peak in the wavelength region of 500 nm to 600 nm. Furthermore, organometallic iridium complexes with pyrimidine skeletons are particularly preferred due to their exceptionally high reliability and luminescence efficiency.

[0280] In addition, examples include organometallic iridium complexes with a pyrimidine skeleton, such as (diisobutyrylmethane)bis[4,6-bis(3-methylphenyl)pyrimidinium]iridium(III) (abbreviated as: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinium](dineopentylmethane)iridium(III) (abbreviated as: [Ir(5mdppm)2(dpm)]), and bis[4,6-bis(naphthyl-1-yl)pyrimidinium](dineopentylmethane)iridium(III) (abbreviated as: [Ir(d1npm)2(dpm)]). Organometallic iridium complexes with a pyrazine skeleton, such as bis(2,3,5-triphenylpyrazine)iridium(III) (abbreviated as [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazine)(dinepentylmethane)iridium(III) (abbreviated as [Ir(tppr)2(dpm)]), and (acetylacetonate)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviated as [Ir(Fdpq)2(acac)]); tris(1-phenylisoquinoline-N,C 2’ Iridium (III) (abbreviated as: [Ir(piq)3]), bis(1-phenylisoquinoline-N,C) 2’ Organometallic iridium complexes with a pyridine skeleton, such as iridium(III)acetylacetone (abbreviated as [Ir(piq)2(acac)]); platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviated as PtOEP); and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monophenyline)europium(III) (abbreviated as [Eu(DBM)3(Phen)]) and tris[1-(2-thiophenecarboxyl)-3,3,3-trifluoroacetone](monophenyline)europium(III) (abbreviated as [Eu(TTA)3(Phen)]). These are compounds that exhibit red phosphorescence and have emission peaks in the wavelength region of 600 nm to 700 nm. In addition, organometallic iridium complexes with pyrazine skeletons can obtain red luminescence with good colorimetry.

[0281] In addition to the phosphorescent compounds mentioned above, other known phosphorescent compounds may also be used.

[0282] Fullerenes and their derivatives, acridines and their derivatives, and eosin derivatives can be used as TADF materials. In addition, metal porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) can also be used. Examples of metalloporphyrins include, for instance, protoporphyrin-tin fluoride complexes represented by the following structural formulas: protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesotoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), tetramethyl coprophyrin-tin fluoride complex (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), protoporphyrin-tin fluoride complex (SnF2(Etio I)), and octaethylporphyrin-platinum chloride complex (PtCl2OEP).

[0283] [Chemical Formula 5]

[0284]

[0285] Alternatively, the following structural formulas can be used: 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazole-11-yl)-1,3,5-triazine (abbreviated as: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviated as: PCCzPTzn), 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1,3 Heterocyclic compounds including 5-triazine (abbreviated: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviated: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-oxazanthracene-9-one (abbreviated: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridin)phenyl]sulfone (abbreviated: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridin-9,9'-anthracene]-10'-one (abbreviated: ACRSA), etc., which include one or both of the π-electron-rich and π-electron-deficient heterocyclic rings. This heterocyclic compound is preferred because it includes both π-electron-rich and π-electron-deficient heteroaromatic rings, thus exhibiting high electron and hole transport properties. Among the skeletons containing π-electron-deficient heteroaromatic rings, pyridine, diazine (pyrimidine, pyrazine, pyridazine), and triazine skeletons are stable and reliable, and are therefore preferred. In particular, benzofuran-pyrimidine, benzothiophene-pyrimidine, benzofuran-pyrazine, and benzothiophene-pyrazine skeletons exhibit high acceptor activity and good reliability, and are therefore preferred. Furthermore, among the skeletons containing π-electron-rich heteroaromatic rings, acridine, phenoxazine, phenothiazine, furan, thiophene, and pyrrole skeletons are stable and reliable, and it is preferred to have at least one of these skeletons. Additionally, dibenzofuran skeletons are preferred as furan skeletons, and dibenzothiophene skeletons are preferred as thiophene skeletons. As the pyrrole skeleton, indole, carbazole, indole-carbazole, bicarbazole, and 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeletons are particularly preferred. In substances where π-electron-rich and π-electron-deficient heteroaromatic rings are directly bonded, the π-electron-rich heteroaromatic ring exhibits high electron-donating and electron-accepting properties, while the energy difference between the S1 and T1 energy levels is smaller, resulting in highly efficient thermally activated delayed fluorescence; therefore, it is particularly preferred. Note that aromatic rings bonded with electron-withdrawing groups such as cyano groups can also be used instead of π-electron-deficient heteroaromatic rings. Furthermore, aromatic amine skeletons and phenazine skeletons can be used as π-electron-rich skeletons.In addition, as π-electron-deficient skeletons, oxanthene skeletons, thioxanthene dioxide skeletons, oxadiazole skeletons, triazole skeletons, imidazole skeletons, anthraquinone skeletons, boron-containing skeletons such as phenylborane and boranthrene, aromatic rings with nitrile or cyano groups such as benzonitrile or cyanobenzene, heteroaromatic rings, carbonyl skeletons such as benzophenone, phosphine oxide skeletons, sulfone skeletons, etc., can be used. Thus, π-electron-deficient and π-electron-rich skeletons can be used to replace at least one of the π-electron-deficient and π-electron-rich heteroaromatic rings.

[0286] [Chemical Formula 6]

[0287]

[0288] Alternatively, TADF materials in thermal equilibrium between singlet and triplet excited states can also be used. These TADF materials have short luminescence lifetimes (excitation lifetimes), thus suppressing efficiency degradation in the high-brightness regions of light-emitting devices. Specifically, materials with the following molecular structures can be cited as examples.

[0289] [Chemical Formula 7]

[0290]

[0291] TADF materials refer to materials where the energy difference between the lowest singlet excitation level (S1 level) and the lowest triplet excitation level (T1 level) is small, and which possess the ability to convert triplet excitation energy into singlet excitation energy via antisystem crossing. Therefore, they can efficiently generate singlet excited states by up-converting triplet excitation energy into singlet excitation energy (antisystem crossing) with minimal thermal energy. Furthermore, triplet excitation energy can be converted into luminescence.

[0292] Exciplexes formed by two substances in an excited state have the function of converting triple excitation energy into single excitation energy due to the extremely small difference between the S1 and T1 energy levels.

[0293] Note that the phosphorescence spectrum observed at low temperatures (e.g., 77K to 10K) can be used as an indicator of the T1 energy level. For TADF materials, it is preferable that the difference between the S1 and T1 energy levels is 0.3 eV or less, more preferably 0.2 eV or less, when the wavelength energy of the extrapolated line obtained by squaring a line at the tail of the short wavelength side of the fluorescence spectrum is taken as the S1 energy level and the wavelength energy of the extrapolated line obtained by squaring a line at the tail of the short wavelength side of the phosphorescence spectrum is taken as the T1 energy level.

[0294] Furthermore, when using TADF material as the luminescent material, the S1 energy level of the host material is preferably higher than that of the TADF material. Additionally, the T1 energy level of the host material is preferably higher than that of the TADF material.

[0295] As the main material of the light-emitting layer, various carrier transport materials such as materials with electron transport properties and / or materials with hole transport properties, the aforementioned TADF materials, etc., can be used.

[0296] As a material with hole transport properties, the materials mentioned above that are examples of materials with hole transport properties can also be used.

[0297] As materials with electron transport properties, the materials mentioned above that are materials with electron transport properties can also be used.

[0298] As a TADF material that can be used as the host material, the materials mentioned above as TADF materials can also be used. When a TADF material is used as the host material, the triple excitation energy generated by the TADF material is converted into a single excitation energy via antisystem crossing and further transferred to the luminescent material, thereby improving the luminous efficiency of the light-emitting device. In this case, the TADF material is used as an energy donor, and the luminescent material is used as an energy acceptor.

[0299] This is highly effective when the luminescent material is a fluorescent luminescent material. Furthermore, to obtain high luminescent efficiency, the S1 energy level of the TADF material is preferably higher than the S1 energy level of the fluorescent luminescent material. Additionally, the T1 energy level of the TADF material is preferably higher than the S1 energy level of the fluorescent luminescent material. Therefore, the T1 energy level of the TADF material is preferably higher than the T1 energy level of the fluorescent luminescent material.

[0300] Furthermore, it is preferable to use a TADF material that exhibits luminescence with a wavelength overlapping the absorption band on the lowest energy side of the fluorescent luminescent material. This allows for efficient transfer of excitation energy from the TADF material to the fluorescent luminescent material, resulting in highly efficient luminescence, and is therefore preferred.

[0301] To efficiently generate a singlet excitation energy from a triplet excitation energy via antisystem crossing, it is preferable to generate carrier recombination within the TADF material. Furthermore, it is preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent luminescent material. For this purpose, the fluorescent luminescent material preferably has a protecting group surrounding the luminescent body (the backbone that causes luminescence) of the fluorescent luminescent material. This protecting group is preferably a substituent without π bonds, preferably a saturated hydrocarbon; specifically, examples include alkyl groups with 3 or more but less than 10 carbon atoms, substituted or unsubstituted cycloalkyl groups with 3 or more but less than 10 carbon atoms, and trialkylsilyl groups with 3 or more but less than 10 carbon atoms; more preferably, multiple protecting groups are preferred. Substituents without π bonds have almost no function in transporting charge carriers, so they have little effect on charge carrier transport or recombination, allowing the TADF material and the luminescent body of the fluorescent luminescent material to be kept apart. Here, the luminescent body refers to the atomic group (backbone) in the fluorescent luminescent material that causes luminescence. The luminescent material preferably has a π-bonded framework, preferably containing an aromatic ring, and even more preferably having a fused aromatic ring or a fused heteroaromatic ring. Examples of such luminescent materials include phenanthrene, stilbene, acridinone, phenoxazine, phenothiazine, naphthalene, anthracene, fluorene, β-carbamate, triphenylene, tetraphenylene, pyrene, perylene, coumarin, quinacridone, and naphthobisbenzofuran frameworks. In particular, fluorescent luminescent materials having naphthalene, anthracene, fluorene, β-carbamate, triphenylene, tetraphenylene, pyrene, perylene, coumarin, quinacridone, and naphthobisbenzofuran frameworks exhibit high fluorescence quantum yields and are therefore preferred.

[0302] When using a fluorescent luminescent material as the luminescent material, a material with an anthracene framework is preferably used as the host material. By using a material with an anthracene framework as the host material of the fluorescent luminescent material, a luminescent layer with high luminous efficiency and durability can be achieved. Among the anthracene framework materials used as host materials, those with a diphenylanthracene framework (especially 9,10-diphenylanthracene framework) are chemically stable and therefore preferred. Furthermore, when the host material has a carbazole framework, hole injection / transport is improved, which is also preferred. However, when a benzo[a]carbazole framework has a benzene ring fused to the carbazole framework, the HOMO level is about 0.1 eV shallower than that of a host material with a carbazole framework, making hole injection easier and therefore more preferred. In particular, when the host material has a dibenzo[a]carbazole framework, its HOMO level is about 0.1 eV shallower than that of a host material with a carbazole framework, which not only facilitates hole injection but also improves hole transport and heat resistance, making it preferred. Therefore, as the host material, a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzo[a]carbazole skeleton or a dibenzo[a]carbazole skeleton) is further preferred. Note that from the viewpoint of hole injection / transportation described above, a benzo[a]fluorene skeleton or a dibenzo[a]fluorene skeleton can also be used instead of a carbazole skeleton. Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (abbreviated: PCzPA), 3-[4-(1-naphthyl)-phenyl]-9-phenyl-9H-carbazole (abbreviated: PCPN), 9-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (abbreviated: CzPA), 7-[4-(10-phenyl-9-anthrayl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviated: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthrayl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviated: 2mBnfPPA), and 9-phenyl-10-[4'-(9-phenyl-9H-fluorene-9-yl] Biphenyl-4-yl]anthracene (abbreviated as FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviated as α,β-ADN), 2-(10-phenylanthracene-9-yl)dibenzofuran, 2-(10-phenyl-9-anthrayl)benzo[b]naphtho[2,3-d]furan (abbreviated as Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviated as βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthrayl]phenyl}-2-ethyl-1H-benzimidazole (abbreviated as EtBImPBPhA), etc. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties and are therefore preferred.

[0303] Alternatively, the host material can be a mixture of multiple substances. When using a mixed host material, it is preferable to mix materials with electron transport properties and materials with hole transport properties. By mixing materials with electron transport properties and materials with hole transport properties, it is easier to adjust the transport properties of the light-emitting layer 113 and to control the rebinding region more easily. The weight ratio of the material with hole transport properties to the material with electron transport properties can be 1:19 to 19:1.

[0304] Note that phosphorescent materials can be used as part of the above-described mixture. When used as a fluorescent material, the phosphorescent material can be used as an energy donor to supply excitation energy to the fluorescent material.

[0305] Alternatively, these mixed materials can be used to form excimer complexes. By selecting a combination of excimer complexes that form light with wavelengths overlapping the absorption band on the lowest energy side of the luminescent material, energy transfer can be facilitated, resulting in efficient luminescence, which is therefore preferred. Furthermore, this structure reduces the driving voltage, making it also preferred.

[0306] Note that at least one of the materials forming the excitocomplex can also be a phosphorescent material. This allows for the efficient conversion of triple excitation energy into single excitation energy via antisystem crossing.

[0307] Regarding the combination of materials for efficiently forming excitocomplexes, the HOMO energy level of the material with hole transport is preferably higher than or equal to the HOMO energy level of the material with electron transport. Furthermore, the LUMO energy level of the material with hole transport is preferably higher than or equal to the LUMO energy level of the material with electron transport. Note that the LUMO and HOMO energy levels of the material can be determined from the electrochemical properties (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0308] Note that the formation of excitocomplexes can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, the emission spectra of an electron-transporting material, and the emission spectra of a hybrid film formed by mixing these materials. When the emission spectrum of the hybrid film is observed to shift towards a longer wavelength (or to have a new peak on the longer wavelength side) compared to the emission spectra of each material, it indicates the formation of an excitocomplex. Alternatively, by comparing the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and the transient PL of a hybrid film formed by mixing these materials, when a difference in transient response is observed, such as the mixed film having a longer lifetime component or a higher ratio of delayed components compared to the transient PL lifetimes of each material, it indicates the formation of an excitocomplex. Furthermore, the aforementioned transient PL can be referred to as transient electroluminescence (EL). In other words, by comparing the transient EL of a hole-transporting material, the transient EL of an electron-transporting material, and the transient EL of a hybrid film of these materials, and observing the differences in transient responses, the formation of an excitocomplex can also be confirmed.

[0309] <<Structure of the Electron Transport Layer>>

[0310] The electron transport layer (electron transport layer 114, first electron transport layer 114_1, second electron transport layer 114_2) is a layer containing a material with electron transport properties. Preferably, the material with electron transport properties has an electron mobility of 1×10⁻⁶ when the square root of the electric field strength [V / cm] is 600. -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 Substances with a value of / Vs or higher. Furthermore, any substance other than those mentioned above can be used as long as its electron transport capability is higher than its hole transport capability. As the aforementioned organic compounds, organic compounds comprising π-electron-deficient heteroaromatic rings are preferred. For example, one or more of the following are preferred: organic compounds comprising a heteroaromatic ring with an azole skeleton, organic compounds comprising a heteroaromatic ring with a pyridine skeleton, organic compounds comprising a heteroaromatic ring with a diazine skeleton, and organic compounds comprising a heteroaromatic ring with a triazine skeleton.

[0311] As for the aforementioned electron-transporting organic compounds that can be used in the electron transport layer, the same organic compounds that can be used in the electron injection layer 115 described in Embodiment 1 can also be used. In particular, organic compounds comprising heteroaromatic rings with a diazine skeleton, organic compounds comprising heteroaromatic rings with a pyridine skeleton, or organic compounds comprising heteroaromatic rings with a triazine skeleton are preferred due to their good reliability. In particular, organic compounds comprising heteroaromatic rings with a diazine (pyrimidine or pyrazine) skeleton and organic compounds comprising heteroaromatic rings with a triazine skeleton have high electron transport properties, which helps to reduce the driving voltage.

[0312] Furthermore, the electron transport layer preferably has an electron mobility of 1×10⁻⁶ when the square root of the electric field strength [V / cm] is 600. -7 cm 2 / Vs or more and 5×10 -5 cm 2 / Vs or less. By reducing the electron transport property in the electron transport layer, the amount of electrons injected into the light-emitting layer can be controlled, thereby preventing the light-emitting layer from becoming an electron-overloaded state. When this structure is used with a deep HOMO level of the hole-transporting material in the hole injection layer, i.e., above -5.7 eV and below -5.4 eV, a long lifetime can be obtained, making it particularly preferred. Note that in this case, the HOMO level of the electron-transporting material is preferably above -6.0 eV.

[0313] <<Structure of the Electron Injection Layer>>

[0314] The structure described in Embodiment 1 can be used as the electron injection layer 115.

[0315] <<Structure of the Second Electrode>>

[0316] The second electrode 102 is an electrode with a cathode. The second electrode 102 may also have a stacked structure, in which case the layer in contact with the organic compound layer 103 serves as the cathode. As the material forming the cathode, metals, alloys, conductive compounds, and mixtures thereof with low work functions (specifically below 3.8 eV) can be used. Specific examples of such cathode materials include alkali metals such as lithium (Li) or cesium (Cs), elements in Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), or strontium (Sr), alloys containing them (MgAg, AlLi), rare earth metals such as europium (Eu), ytterbium (Yb), and alloys containing them. However, by providing an electron injection layer between the second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, and indium oxide-tin oxide containing silicon or silicon oxide can be used as the cathode regardless of the work function.

[0317] When the second electrode 102 is formed of a material that is transmissive to visible light, a light-emitting device that emits light from one side of the second electrode 102 can be formed.

[0318] These conductive materials can be deposited using dry methods such as vacuum evaporation or sputtering, inkjet printing, or spin coating. Alternatively, they can be formed using wet methods such as sol-gel or wet methods using pastes of metallic materials.

[0319] Furthermore, various methods, whether dry or wet, can be used to form the organic compound layer 103. For example, vacuum evaporation, gravure printing, offset printing, screen printing, inkjet printing, or spin coating can also be used.

[0320] Alternatively, the electrodes or layers described above can be formed by using different deposition methods.

[0321] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, in this specification, where multiple structural examples are shown in one embodiment, these structural examples can be appropriately combined.

[0322] (Implementation Method 3)

[0323] like Figure 7A and Figure 7B As shown, a plurality of light-emitting devices 130 are formed on an insulating layer 175 to constitute a display device. In this embodiment, a display device according to one aspect of the present invention will be described in detail.

[0324] The display device 100 includes a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. The pixels 178 include sub-pixels 110R, 110G, and 110B.

[0325] In this specification, etc., the term "subpixel 110" is sometimes used to describe the common features among subpixels 110R, 110G, and 110B. Furthermore, regarding other constituent elements distinguished by letters, reference numerals with omitted letters are sometimes used to describe the common features among these constituent elements.

[0326] Subpixel 110R emits red light, subpixel 110G emits green light, and subpixel 110B emits blue light. Thus, an image can be displayed on pixel unit 177. Note that in this embodiment, only three subpixels of red (R), green (G), and blue (B) are used as examples; other colors of subpixels can also be combined. Furthermore, the number of subpixels is not limited to three; four or more can be used. Examples of four subpixels include: subpixels of four colors (R, G, B, and white (W); subpixels of four colors (R, G, B, and Y (yellow); and subpixels of four colors (R, G, B, and infrared (IR)); etc.

[0327] In this specification, the row direction is sometimes referred to as the X direction and the column direction as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0328] exist Figure 7A In the example shown, subpixels of different colors are arranged in the X direction, and subpixels of the same color are arranged in the Y direction. Note that it is also possible to arrange subpixels of different colors in the Y direction and subpixels of the same color in the X direction.

[0329] A connecting portion 140 may be provided on the outer side of the pixel portion 177, and a region 141 may also be provided. For example, the region 141 may be provided between the pixel portion 177 and the connecting portion 140. An organic compound layer 103 may be provided in the region 141. In addition, a conductive layer 151C may be provided in the connecting portion 140.

[0330] exist Figure 7A In the example shown, region 141 and connecting portion 140 are located to the right of pixel portion 177, but there are no particular restrictions on the position of region 141 and connecting portion 140. Alternatively, region 141 and connecting portion 140 may be one or more.

[0331] Figure 7B It is along Figure 7A An example of a cross-sectional view of the dashed-dot line A1-A2 in the diagram. For example... Figure 7B As shown, the display device 100 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and the conductive layer 172, an insulating layer 174 on the insulating layer 173, and an insulating layer 175 on the insulating layer 174. The insulating layer 171 is disposed on a substrate (not shown). The insulating layers 175, 174, and 173 are provided with openings leading to the conductive layer 172, and a plug 176 is disposed such that it is inserted into the openings.

[0332] In the pixel section 177, a light-emitting device 130 is disposed on the insulating layer 175 and the plug 176. A protective layer 131 is disposed to cover the light-emitting device 130. The substrate 120 is attached to the protective layer 131 by a resin layer 122. In addition, it is preferable to provide an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 between adjacent light-emitting devices 130.

[0333] Figure 7B Cross-sections of multiple inorganic insulating layers 125 and multiple insulating layers 127 are shown, but when viewed from above the display device 100, the inorganic insulating layers 125 and insulating layers 127 are preferably formed as continuous layers. That is, the inorganic insulating layers 125 and insulating layers 127 are preferably insulating layers having openings on the first electrode.

[0334] Figure 7B Light-emitting devices 130R, 130G, and 130B are shown as light-emitting device 130. Light-emitting devices 130R, 130G, and 130B emit light of different colors. For example, light-emitting device 130R may emit red light, light-emitting device 130G may emit green light, and light-emitting device 130B may emit blue light. Alternatively, light-emitting devices 130R, 130G, or 130B may also emit other visible or infrared light.

[0335] One aspect of the display device of the present invention may have a top emission structure that emits light in a direction opposite to that of the substrate on which the light-emitting device is formed. Alternatively, another aspect of the display device of the present invention may have a bottom emission structure.

[0336] Examples of luminescent materials contained in the light-emitting device 130 include organic compounds or organometallic complexes that emit fluorescence (fluorescent materials), emit phosphorescence (phosphorescent materials), and exhibit thermally activated delayed fluorescence (TADF) materials. Alternatively, inorganic compounds such as quantum dots may also be used.

[0337] The light-emitting device 130R has the structure shown in Embodiment 1. The light-emitting device 130R includes a first electrode (pixel electrode) composed of conductive layers 151R and 152R, an organic compound layer 103R on the first electrode, a common layer 104 on the organic compound layer 103R, and a second electrode (common electrode) 155 on the common layer 104. The common layer 104 may or may not be provided, but its presence reduces damage to the organic compound layer 103R during processing, making it preferred. When the common layer 104 is provided, it is preferably an electron injection layer. Furthermore, when the common layer 104 is not provided, the organic compound layer 103R corresponds to the organic compound layer 103 in Embodiments 1 and 2. When the common layer 104 is provided, the stacked structure of the organic compound layer 103R and the common layer 104 corresponds to the organic compound layer 103 in Embodiments 1 and 2.

[0338] The light-emitting device 130G has the structure shown in Embodiment 1. The light-emitting device 130G includes a first electrode (pixel electrode) composed of conductive layers 151G and 152G, an organic compound layer 103G on the first electrode, a common layer 104 on the organic compound layer 103G, and a second electrode (common electrode) 155 on the common layer 104. The common layer 104 may or may not be provided, but its presence reduces damage to the organic compound layer 103G during processing, making it preferred. Furthermore, when the common layer 104 is not provided, the organic compound layer 103G is equivalent to the organic compound layer 103 in Embodiments 1 and 2. When the common layer 104 is provided, the stacked structure of the organic compound layer 103G and the common layer 104 is equivalent to the organic compound layer 103 in Embodiments 1 and 2.

[0339] The light-emitting device 130B has the structure shown in Embodiment 1. The light-emitting device 130B includes a first electrode (pixel electrode) composed of conductive layers 151B and 152B, an organic compound layer 103B on the first electrode, a common layer 104 on the organic compound layer 103B, and a second electrode (common electrode) 155 on the common layer 104. The common layer 104 may or may not be provided, but its presence reduces damage to the organic compound layer 103B during processing, making it preferred. Furthermore, when the common layer 104 is not provided, the organic compound layer 103B is equivalent to the organic compound layer 103 in Embodiments 1 and 2. When the common layer 104 is provided, the stacked structure of the organic compound layer 103B and the common layer 104 is equivalent to the organic compound layer 103 in Embodiments 1 and 2.

[0340] In a light-emitting device, one of the pixel electrode and the common electrode is used as the anode, and the other is used as the cathode. Unless otherwise specified, the following description assumes that the pixel electrode is used as the anode and the common electrode is used as the cathode.

[0341] Organic compound layers 103R, 103G, and 103B are arranged in an island shape according to the light-emitting device or according to each light-emitting color. By setting the organic compound layers 103 in an island shape according to each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can also be suppressed in high-definition display devices. This prevents crosstalk and enables display devices with extremely high contrast. In particular, it enables display devices with high current efficiency at low brightness.

[0342] An island-like organic compound layer 103 is formed by depositing an EL film and processing it using photolithography.

[0343] Furthermore, in one embodiment of the display device of the present invention, the first electrode (pixel electrode) of the light-emitting device preferably has a stacked structure. For example, in Figure 7B In the example shown, the first electrode of the light-emitting device 130 has a stacked structure of conductive layer 151 and conductive layer 152. For example, when the display device 100 has a top-emitting structure and the pixel electrode of the light-emitting device 130 is used as the anode, it is preferable that the conductive layer 151 is a layer with high visible light reflectivity, and the conductive layer 152 is, for example, a layer with visible light transmittance and a large work function. When the display device 100 has a top-emitting structure, the higher the visible light reflectivity of the pixel electrode, the higher the extraction efficiency of the light emitted by the organic compound layer 103. In addition, when the pixel electrode is used as the anode, the larger the work function of the pixel electrode, the easier it is to inject holes into the organic compound layer 103. Thus, by having a stacked structure of conductive layer 151 with high visible light reflectivity and conductive layer 152 with a large work function in the pixel electrode of the light-emitting device 130, the light-emitting device 130 can be a light-emitting device with high light extraction efficiency and low driving voltage.

[0344] When the conductive layer 151 is a layer with high visible light reflectivity, the visible light reflectivity of the conductive layer 151 is preferably 40% or more and 100% or less, more preferably 70% or more and 100% or less. Furthermore, when the conductive layer 152 is an electrode with visible light transmittance, the visible light transmittance is preferably 40% or more.

[0345] In cases where the pixel electrode has a multi-layered stacked structure, the pixel electrode may deteriorate due to reactions between these layers. For example, when the film formed after the pixel electrode is formed is removed by wet etching, galvanic corrosion occurs due to the contact of the chemical solution with the pixel electrode.

[0346] Therefore, in the display device 100 of this embodiment, an insulating layer 156 is formed on the sides of the conductive layers 151 and 152. This prevents the contact of the chemical solution with the conductive layer 151, for example, when removing the film formed after the pixel electrode including the conductive layers 151 and 152 is formed using a wet etching method. Thus, galvanic corrosion in the pixel electrode can be suppressed, for example. Therefore, the display device 100 can be manufactured using a high-yield method, resulting in a low-cost display device. Furthermore, defects in the display device 100 can be suppressed, making it a highly reliable display device.

[0347] As the conductive layer 151, a metallic material can be used, for example. Specifically, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), and alloys thereof can also be used.

[0348] As the conductive layer 152, an oxide containing one or more of indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, conductive oxides containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, gallium-containing zinc oxide, titanium oxide, gallium-containing indium zinc oxide, aluminum-containing indium zinc oxide, silicon-containing indium tin oxide, and silicon-containing indium zinc oxide are preferred. In particular, silicon-containing indium tin oxide has a large work function, for example, 4.0 eV or more, so it can be used in the conductive layer 152.

[0349] Conductive layer 151 and conductive layer 152 may each have a stacked structure containing multiple layers of different materials. In this case, conductive layer 151 may also include a layer using a material that can be used in conductive layer 152, such as a conductive oxide, and conductive layer 152 may also include a layer using a material that can be used in conductive layer 151, such as a metallic material. For example, when conductive layer 151 has a stacked structure of two or more layers, the layer in contact with conductive layer 152 may be a layer using a material that can be used in conductive layer 152.

[0350] Note that the end of the insulating layer 156 may also have a tapered shape. Specifically, when the end of the insulating layer 156 has a tapered shape with a taper angle of less than 90°, the coverage of structures disposed along the side of the insulating layer 156 can be improved.

[0351] Figure 8A This is a diagram showing a conductive layer 151 with a stacked structure containing multiple layers of different materials. (See diagram below.) Figure 8AAs shown, the conductive layer 151 includes a conductive layer 151a, a conductive layer 151b on the conductive layer 151a, and a conductive layer 151c on the conductive layer 151b. That is, Figure 8A The conductive layer 151 shown has a three-layer stacked structure. Thus, when the conductive layer 151 has a multi-layer stacked structure, it is possible to make the visible light reflectivity of at least one of the layers constituting the conductive layer 151 higher than that of the conductive layer 152.

[0352] exist Figure 8A In the example shown, conductive layer 151b is sandwiched between conductive layers 151a and 151c. Conductive layers 151a and 151c can be made of materials less prone to degradation than conductive layer 151b. For example, conductive layer 151a can be made of a material less prone to migration due to contact with insulating layer 175 compared to conductive layer 151b. Furthermore, conductive layer 151c can be made of a material that is less prone to oxidation than conductive layer 151b, and whose oxide has a lower resistivity than the oxide of the material used for conductive layer 151b.

[0353] Thus, by employing a structure in which conductive layer 151b is sandwiched between conductive layer 151a and conductive layer 151c, the range of materials that can be selected for conductive layer 151b can be expanded. For example, conductive layer 151b can be a layer whose visible light reflectance is higher than at least one of conductive layer 151a and conductive layer 151c. For example, aluminum can be used as conductive layer 151b. Alternatively, an aluminum-containing alloy can also be used as conductive layer 151b. Furthermore, titanium can be used as conductive layer 151a. While titanium has a lower visible light reflectance than aluminum, it is less prone to migration even when in contact with insulating layer 175 compared to aluminum. And titanium can be used as conductive layer 151c. While titanium has a lower visible light reflectance than aluminum, it is less prone to oxidation than aluminum, and the resistivity of its oxide is lower than that of aluminum oxide.

[0354] Alternatively, silver or a silver-containing alloy can be used as the conductive layer 151c. Silver has a higher visible light reflectance than titanium. Furthermore, silver has the following properties: it is less prone to oxidation than aluminum, and the resistivity of silver oxide is lower than that of aluminum oxide. Therefore, when silver or a silver-containing alloy is used as the conductive layer 151c, the visible light reflectance of the conductive layer 151 can be appropriately increased while suppressing the increase in resistance of the pixel electrode caused by oxidation of the conductive layer 151b. Here, an alloy of silver, palladium, and copper (Ag-Pd-Cu, also denoted as APC) can be used as the silver-containing alloy, for example. Additionally, when silver or a silver-containing alloy is used as the conductive layer 151c and aluminum is used as the conductive layer 151b, the visible light reflectance of the conductive layer 151c can be increased compared to the visible light reflectance of the conductive layer 151b. Here, silver or a silver-containing alloy can also be used as the conductive layer 151b. Furthermore, silver or a silver-containing alloy can also be used as the conductive layer 151a.

[0355] On the other hand, the etching processability of films using titanium is superior to that using silver. Therefore, by using titanium as the conductive layer 151c, the conductive layer 151c can be easily formed. In addition, the etching processability of films using aluminum is also superior to that using silver.

[0356] Thus, by having a multi-layered stacked structure for the conductive layer 151, the characteristics of the display device can be improved. For example, the display device 100 can be made into a display device with high light extraction efficiency and high reliability.

[0357] Here, when the light-emitting device 130 adopts a microcavity structure, by using silver or a silver-containing alloy, which are materials with high visible light reflectivity, as the conductive layer 151c, the light extraction efficiency of the display device 100 can be appropriately improved.

[0358] As described above, the side surface of the conductive layer 151 preferably has a tapered shape. Specifically, the side surface of the conductive layer 151 preferably has a tapered shape with a taper angle of less than 90°. For example, in Figure 8A In the conductive layer 151 of the structure shown, preferably, at least one of the conductive layers 151a, 151b and 151c has a tapered shape on its side.

[0359] Figure 8AThe conductive layer 151 shown can be formed using photolithography. Specifically, first, conductive films that will become conductive layer 151a, conductive films that will become conductive layer 151b, and conductive films that will become conductive layer 151c are deposited sequentially. Next, a photoresist mask is formed on the conductive film that will become conductive layer 151c. Then, the conductive film in areas that do not overlap with the photoresist mask is removed, for example, by etching. Here, by processing the conductive film under conditions where the photoresist mask is easier to retract (shrink) compared to forming the conductive layer 151 in a manner where the sides do not have a tapered shape (i.e., the sides are vertical), a conductive layer 151 with a tapered shape on the sides can be formed.

[0360] Here, when processing the conductive film under conditions where the resist mask can easily recede (shrink), the conductive film is sometimes easily processed in the horizontal direction. In other words, compared to the case where the conductive layer 151 is formed in a manner where the sides are perpendicular, the isotropy of the etching is sometimes higher.

[0361] Furthermore, when the conductive layer 151 has a stacked structure of multiple layers made of different materials, the ease of processing of these multiple layers in the horizontal direction may sometimes differ. For example, the ease of processing of conductive layer 151a, conductive layer 151b, and conductive layer 151c in the horizontal direction may sometimes differ.

[0362] In this case, sometimes after processing the conductive film, such as Figure 8A As shown, the side of conductive layer 151b is located inside the side of conductive layers 151a and 151c, forming a recess. Therefore, there is a concern that the coverage of conductive layer 152 over conductive layer 151 may decrease, potentially leading to a break in conductive layer 152.

[0363] Therefore, the preferred option is as follows: Figure 8A That's how you set up the insulation layer 156. Figure 8A An example is shown in which an insulating layer 156 is provided on the conductive layer 151a in such a way that it has a region overlapping the side surface of the conductive layer 151b. This can suppress the breakage or thinning of the conductive layer 152 caused by the recess, thus suppressing poor connections or rising drive voltage.

[0364] Note that, although Figure 8A The diagram shows a structure in which the entire side of the conductive layer 151b is covered by the insulating layer 156, but a portion of the side of the conductive layer 151b may not be covered by the insulating layer 156. The same applies to a pixel electrode with the structure shown below, where a portion of the side of the conductive layer 151b may also not be covered by the insulating layer 156.

[0365] The conductive layer 151 has Figure 8AIn the structure shown, conductive layer 152 covers conductive layers 151a, 151b, 151c, and insulating layer 156, and is electrically connected to conductive layers 151a, 151b, and 151c. Therefore, even when removing the film deposited after the formation of conductive layer 152 by wet etching, for example, the chemical solution can be prevented from contacting conductive layers 151a, 151b, and 151c. Thus, corrosion in conductive layers 151a, 151b, and 151c can be suppressed. Therefore, the display device 100 can be manufactured with a high yield. Furthermore, the occurrence of defects can be suppressed, resulting in a display device 100 with high reliability.

[0366] Here, as Figure 8A As shown, the insulating layer 156 preferably has a curved surface. This reduces the likelihood of breaks in the conductive layer 152 covering the insulating layer 156 compared to the case where the insulating layer 156 is perpendicular to its side surface (parallel to the Z direction). Furthermore, when the insulating layer 156 has a tapered shape on its side surface, specifically a tapered shape with a taper angle of less than 90°, this also reduces the likelihood of breaks in the conductive layer 152 covering the insulating layer 156 compared to the case where the insulating layer 156 is perpendicular to its side surface. This allows for the manufacture of the display device 100 with a high yield rate. Additionally, it reduces the occurrence of defects, resulting in a display device 100 with high reliability.

[0367] Notice, Figure 8A The diagram shows a structure where the side surface of conductive layer 151b is located inside the side surface of conductive layer 151a and the side surface of conductive layer 151c. However, the invention is not limited to this configuration. For example, the side surface of conductive layer 151b may also be located outside the side surface of conductive layer 151a. Additionally, the side surface of conductive layer 151b may also be located outside the side surface of conductive layer 151c.

[0368] Figures 8B to 8D Other structures of the first electrode 101 are shown. Figure 8B Shown in Figure 8A The first electrode 101 has an insulating layer 156 that covers the sides of conductive layers 151a, 151b and 151c in addition to the sides of conductive layers 151b.

[0369] Figure 8C Shown in Figure 8A The first electrode 101 does not have an insulating layer 156.

[0370] Figure 8D The following structure is shown: In Figure 8A In the first electrode 101, the conductive layer 151 does not have a stacked structure while the conductive layer 152 has a stacked structure.

[0371] The conductive layer 152a has a higher adhesion to the conductive layer 152b than, for example, the insulating layer 175. As the conductive layer 152a, for example, an oxide containing one or more of indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, it is preferable to use a conductive oxide containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium titanium oxide, zinc titanate, aluminum zinc oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon. This suppresses film peeling of the conductive layer 152b. Furthermore, it prevents the conductive layer 152b from contacting the insulating layer 175.

[0372] The conductive layer 152b is a layer with a higher visible light reflectance (e.g., reflectance of light of a specified wavelength in the range of 400 nm and above to less than 750 nm) than the conductive layers 151, 152a, and 152c. The visible light reflectance of the conductive layer 152b can be, for example, 70% or more and 100% or less, preferably 80% or more and 100% or less, and more preferably 90% or more and 100% or less. Furthermore, as the conductive layer 152b, a material with a visible light reflectance higher than that of aluminum can be used, for example. Specifically, for example, silver or a silver-containing alloy can be used as the conductive layer 152b. Examples of silver-containing alloys include, for example, an alloy of silver, palladium, and copper (APC). This allows the display device 100 to become a display device with high light extraction efficiency. Note that metals other than silver can also be used as the conductive layer 152b.

[0373] When conductive layers 151 and 152 are used as anodes, conductive layer 152c is preferably a layer with a high work function. For example, conductive layer 152c is a layer with a work function larger than that of conductive layer 152b. As conductive layer 152c, for example, the same material used for conductive layer 152a can be used. For example, the same material can be used for both conductive layer 152a and conductive layer 152c. For example, when indium tin oxide is used for conductive layer 152a, indium tin oxide can also be used for conductive layer 152c.

[0374] Note that when conductive layers 151 and 152 are used as cathodes, conductive layer 152c is preferably a layer with a small work function. For example, conductive layer 152c is a layer with a smaller work function than conductive layer 152b.

[0375] Furthermore, the conductive layer 152c is preferably a layer with high visible light transmittance (e.g., transmittance of light in the range of 400 nm and above but less than 750 nm). For example, the visible light transmittance of the conductive layer 152c is preferably higher than that of the conductive layers 151 and 152b. For example, the visible light transmittance of the conductive layer 152c can be 60% or more and 100% or less, preferably 70% or more and 100% or less, and more preferably 80% or more and 100% or less. This reduces the amount of light absorbed by the conductive layer 152c from the light emitted by the organic compound layer 103. In addition, as described above, the conductive layer 152b below the conductive layer 152c can be a layer with high visible light reflectance. Therefore, the display device 100 can be made into a display device with high light extraction efficiency.

[0376] Next, refer to Figures 9A to 14C The description has Figure 7A An example of a manufacturing method for the display device 100 with the shown structure. The organic compound layer of the light-emitting device included in the display device 100 is formed by a manufacturing process including water treatment. By using the light-emitting device of one aspect of the present invention in the display device as an example of the present invention, a display device including a light-emitting device with reduced driving voltage and high luminous efficiency can be provided.

[0377] [Example of manufacturing method]

[0378] Thin films (insulating films, semiconductor films, conductive films, etc.) constituting display devices can be formed using methods such as sputtering, chemical vapor deposition (CVD), vacuum evaporation, pulsed laser deposition (PLD), or atomic layer deposition (ALD). CVD methods include plasma-enhanced chemical vapor deposition (PECVD) and thermal CVD. Additionally, metal-organic chemical vapor deposition (MOCVD) is one type of thermal CVD method.

[0379] In addition, the thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed using wet deposition methods such as spin coating, dip coating, spray coating, inkjet coating, dispenser coating, screen printing, offset printing, doctor knife coating, slot coating, roller coating, curtain coating, or doctor knife coating.

[0380] In particular, when manufacturing light-emitting devices, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet printing can be utilized. Examples of vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam vapor deposition, molecular beam vapor deposition, and vacuum vapor deposition, as well as chemical vapor deposition (CVD). Specifically, functional layers (hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, and electron injection layer, etc.) comprising an organic compound layer can be formed using methods such as vapor deposition (vacuum vapor deposition, etc.), coating methods (dip coating, dye coating, rod coating, spin coating, spray coating), and printing methods (inkjet printing, screen printing, offset printing, flexographic printing, photogravure printing, or microcontact printing, etc.).

[0381] Furthermore, when processing the thin film constituting the display device, techniques such as lithography can be used. Alternatively, nanoimprinting, sandblasting, or lift-off methods can be employed. Additionally, island-shaped thin films can be directly formed using deposition methods that utilize metal masks or similar masking techniques.

[0382] As a lithography technique, photolithography can be used, for example. Photolithography typically involves two methods. One is to form a resist mask on the thin film to be processed, for example, by etching the film and then removing the resist mask. The other is to deposit a photosensitive thin film, then expose and develop it to process the film into the desired shape.

[0383] In photolithography, the light used for exposure can be, for example, i-line (wavelength 365nm), g-line (wavelength 436nm), h-line (wavelength 405nm), or a mixture of these. Alternatively, ultraviolet light, KrF lasers, or ArF lasers can also be used. Immersion exposure can also be employed. Extreme ultraviolet (EUV) light or X-rays can also be used as the light for exposure. Alternatively, an electron beam can be used instead of the light for exposure. Extreme ultraviolet light, X-rays, or electron beams allow for extremely fine processing and are therefore preferred. Furthermore, when exposure is performed by scanning with a beam such as an electron beam, a photomask is not required.

[0384] In the etching of thin films, dry etching, wet etching, or sandblasting methods can be used.

[0385] First, such as Figure 9AAn insulating layer 171 is formed on a substrate (not shown). Next, a conductive layer 172 and a conductive layer 179 are formed on the insulating layer 171, and an insulating layer 173 is formed on the insulating layer 171 to cover the conductive layers 172 and 179. Next, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0386] As a substrate, a substrate with heat resistance sufficient to withstand subsequent heat treatment can be used. When using an insulating substrate, glass substrates, quartz substrates, sapphire substrates, ceramic substrates, or organic resin substrates can be used. In addition, single-crystal semiconductor substrates or polycrystalline semiconductor substrates made of materials such as silicon or silicon carbide, compound semiconductor substrates made of materials such as silicon-germanium, SOI substrates, and other semiconductor substrates can also be used.

[0387] Next, as Figure 9A As shown, openings leading to the conductive layer 172 are formed in insulating layers 175, 174, and 173. Then, a plug 176 is formed by embedding it into these openings.

[0388] Next, as Figure 9A As shown, a conductive film 151f, which will later become conductive layers 151R, 151G, 151B, and 151C, is formed on the plug 176 and the insulating layer 175. The conductive film 151f can be formed, for example, by sputtering or vacuum evaporation. Alternatively, a metallic material can be used as the conductive film 151f.

[0389] Next, as Figure 9A As shown, a conductive film 152f, which will later become conductive layers 152R, 152G, 152B, and 152C, is formed on a conductive film 151f. The conductive film 152f can be formed, for example, by sputtering or vacuum evaporation. Alternatively, a conductive oxide can be used as the conductive film 152f. Or, the conductive film 152f can be a laminated structure of a film using a metallic material and a film using a conductive oxide on that film. For example, the conductive film 152f can be a laminated structure of a film using titanium, silver, or a silver-containing alloy and a film using a conductive oxide on that film.

[0390] Furthermore, the conductive film 152f can be formed using the ALD method. Here, as the conductive film 152f, an oxide containing one or more metals selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. The conductive film 152f can be formed by repeatedly performing a cycle of introducing a precursor (sometimes referred to as a precursor or metal precursor, etc.), purging the precursor, introducing an oxidant (sometimes referred to as a reactant, reactant, or non-metal precursor, etc.), and purging the oxidant. When forming a conductive film 152f from an oxide film containing multiple metals, such as indium tin oxide, the metal composition can be controlled by changing the number of cycles according to the type of precursor.

[0391] For example, in the case of depositing an indium tin oxide film as a conductive film 152f, after introducing an indium-containing precursor, the precursor is purged and an oxidant is introduced to form an In-O film. Next, after introducing a tin-containing precursor, the precursor is purged and an oxidant is introduced to form a Sn-O film. Here, by making the number of cycles for forming the In-O film greater than the number of cycles for forming the Sn-O film, the number of In atoms contained in the conductive film 152f can be greater than the number of Sn atoms.

[0392] Furthermore, for example, when depositing a zinc oxide film as the conductive film 152f, a Zn-O film is formed through the above process. Furthermore, for example, when depositing an aluminum-zinc oxide film as the conductive film 152f, both a Zn-O film and an Al-O film are formed through the above process. Furthermore, for example, when depositing a titanium oxide film as the conductive film 152f, a Ti-O film is formed through the above process. Furthermore, for example, when depositing an indium tin oxide film containing silicon as the conductive film 152f, an In-O film, a Sn-O film, and a Si-O film are formed through the above process. Furthermore, for example, when depositing a zinc oxide film containing gallium, both a Ga-O film and a Zn-O film are formed through the above process.

[0393] As indium-containing precursors, for example, triethylindium, trimethylindium, or [1,1,1-trimethyl-N-(trimethylsilyl)amide]-indium can be used. As tin-containing precursors, for example, tin chloride or tetra(dimethylamide)tin can be used. As zinc-containing precursors, for example, diethylzinc or dimethylzinc can be used. As gallium-containing precursors, for example, triethylgallium can be used. As titanium-containing precursors, for example, titanium chloride, tetra(dimethylamide)titanium, or tetraisopropyl titanate can be used. As aluminum-containing precursors, for example, aluminum chloride or trimethylaluminum can be used. As silicon-containing precursors, for example, trisilylamine, bis(diethylamino)silane, tri(dimethylamino)silane, bis(tert-butylamino)silane, or bis(ethylmethylamino)silane can be used. Additionally, water vapor, oxygen plasma, or ozone gas can be used as oxidants.

[0394] Next, as Figure 9A As shown, a photoresist mask 191 is formed on conductive films 151f and 152f. The photoresist mask 191 can be formed by coating a photosensitive material (photoresist) and then exposing and developing it.

[0395] Next, as Figure 9B As shown, conductive films 151f and 152f, for example, are removed using an etching method, specifically a dry etching method, to remove areas of the conductive film 151f and 152f that do not overlap with the resist mask 191, thereby forming a pixel electrode including conductive layers 151 and 152. Note that if conductive film 151f includes a layer of conductive oxide such as indium tin oxide, this layer can also be removed using a wet etching method. Thus, conductive layers 151 and 152 are formed. Note that, for example, when a portion of conductive film 151f is removed using a dry etching method, a recess may sometimes be formed in an area of ​​the insulating layer 175 that does not overlap with conductive layer 151.

[0396] Note that, after forming conductive layers 152R, 152G, 152B, and 152C by processing conductive film 152f using lithography, conductive film 151f can be processed using conductive layers 152R, 152G, 152B, and 152C as masks. Specifically, for example, after forming a resist mask, a portion of conductive film 152f can be removed using an etching method. For example, wet etching can be used to remove conductive film 152f. Note that dry etching can also be used to remove conductive film 152f. Then, wet etching is preferably used to remove conductive film 151f.

[0397] Next, as Figure 9C As shown, the resist mask 191 is removed. The resist mask 191 can be removed, for example, by ashing using oxygen plasma. Alternatively, oxygen gas and Group 18 elements such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He can be used. Alternatively, the resist mask 191 can also be removed by wet etching.

[0398] Here, it is preferable to perform a hydrophobic treatment on the conductive layer 152. This hydrophobic treatment can change the surface state of the object being treated from hydrophilic to hydrophobic, or it can increase the hydrophobicity of the surface. By performing a hydrophobic treatment on the conductive layer 152, the adhesion between the conductive layer 152 and the organic compound layer 103 to be formed in subsequent processes can be improved, thereby suppressing film peeling. Note that a hydrophobic treatment may not be performed.

[0399] Next, as Figure 9DAs shown, an insulating film 156f, which will later become insulating layers 156R, 156G, 156B, and 156C, is formed on conductive layers 151R, 152R, 151G, 152G, 151B, 152B, 151C, and 152C, and insulating layer 175. The insulating film 156f can be formed, for example, using CVD, ALD, sputtering, or vacuum evaporation.

[0400] Inorganic materials can be used for the insulating film 156f. For example, inorganic insulating films such as oxide insulating films, nitride insulating films, oxynitride insulating films, or oxynitride insulating films can be used as the insulating film 156f. For instance, silicon-containing insulating films such as oxide insulating films, nitride insulating films, oxynitride insulating films, or oxynitride insulating films can be used as the insulating film 156f. For example, silicon oxynitride can be used as the insulating film 156f.

[0401] Next, as Figure 9E As shown, insulating film 156f is processed to form insulating layers 156R, 156G, 156B, and 156C. For example, insulating layer 156 can be formed by etching the top surface of insulating film 156f in a substantially uniform manner. This planarization process through uniform etching is also known as etch-back. Alternatively, insulating layer 156 can also be formed using photolithography.

[0402] Next, as Figure 10A As shown, an organic compound film 103Rf, which will later become an organic compound layer 103R, is formed on conductive layer 152R, conductive layer 152G, conductive layer 152B, insulating layer 156R, insulating layer 156G, insulating layer 156B and insulating layer 175.

[0403] like Figure 10A As shown, no organic compound film 103Rf is formed on the conductive layer 152C. For example, by using a mask that defines the deposition area (also called a zone mask or coarse metal mask, etc., to distinguish it from a high-precision metal mask), the organic compound film 103Rf can be deposited only in the desired area. By employing a deposition process using a zone mask and a processing process using a resist mask, the light-emitting device can be manufactured with a simpler process.

[0404] The organic compound film 103Rf can be formed, for example, by vapor deposition, specifically by vacuum vapor deposition. Alternatively, the organic compound film 103Rf can also be formed by methods such as transfer printing, printing, inkjet printing, and coating.

[0405] Next, as Figure 10AAs shown, a sacrificial film 158Rf, which will later become a sacrificial layer 158R, and a mask film 159Rf, which will later become a mask layer 159R, are sequentially formed on an organic compound film 103Rf, a conductive layer 152C, and an insulating layer 175.

[0406] Note that in this embodiment, an example is shown where the mask film consists of a two-layer structure of sacrificial film 158Rf and mask film 159Rf. However, the mask film may have a single-layer structure or a stacked structure of three or more layers. Furthermore, in this specification and the like, the mask layer may be referred to as the sacrificial layer and the mask film as the sacrificial film.

[0407] By providing a sacrificial layer on the organic compound film 103Rf, the damage to the organic compound film 103Rf during the manufacturing process of the display device can be reduced, thereby improving the reliability of the light-emitting device.

[0408] The sacrificial film 158Rf is a film with high tolerance to the processing conditions of the organic compound film 103Rf, specifically a film with a greater etch selectivity than the organic compound film 103Rf. The mask film 159Rf is a film with a greater etch selectivity than the sacrificial film 158Rf.

[0409] Furthermore, the sacrificial film 158Rf and the mask film 159Rf are formed at a temperature lower than the heat resistance temperature of the organic compound film 103Rf. The substrate temperature during the formation of the sacrificial film 158Rf and the sacrificial film 159Rf is typically below 200°C, preferably below 150°C, more preferably below 120°C, further preferably below 100°C, and even more preferably below 80°C.

[0410] The sacrificial film 158Rf and the mask film 159Rf are preferably films that can be removed by wet etching. By using wet etching, the damage to the organic compound film 103Rf during the processing of the sacrificial film 158Rf and the mask film 159Rf can be reduced compared to using dry etching.

[0411] The sacrificial film 158Rf and the mask film 159Rf can be formed, for example, by sputtering, ALD (thermal ALD, PEALD), CVD, or vacuum evaporation. Alternatively, they can also be formed using the aforementioned wet deposition methods.

[0412] The sacrificial film 158Rf formed on the organic compound film 103Rf is preferably formed by a method that causes less damage to the organic compound film 103Rf compared to the formation of the mask film 159Rf. For example, the sacrificial film 158Rf is more preferably formed by ALD or vacuum evaporation than by sputtering.

[0413] As the sacrificial film 158Rf and the mask film 159Rf, one or more of the following can be used: metal film, alloy film, metal oxide film, semiconductor film, organic insulating film and inorganic insulating film.

[0414] The sacrificial film 158Rf and the mask film 159Rf can each be made of metallic materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloys containing such metallic materials. Low-melting-point materials such as aluminum or silver are particularly preferred. By using a metallic material capable of blocking ultraviolet light as one or both of the sacrificial film 158Rf and the mask film 159Rf, ultraviolet light irradiation onto the organic compound film 103Rf can be suppressed, thereby suppressing the degradation of the organic compound film 103Rf, which is therefore preferred.

[0415] In addition, the sacrificial film 158Rf and the mask film 159Rf can each be 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), or indium tin oxide containing silicon.

[0416] Note that element M (which is one or more of aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) can also be used to replace gallium.

[0417] Furthermore, the sacrificial film and mask film preferably use films containing materials with light-shielding properties, especially ultraviolet light-shielding properties. As the light-shielding material, various materials such as metals, insulators, semiconductors, and semi-metals with ultraviolet light-shielding properties can be used. Since part or all of the sacrificial film and mask film will be removed in subsequent processes, the sacrificial film and mask film are preferably films that can be processed by etching, and especially preferably films with good processability.

[0418] When using semiconductor materials such as silicon or germanium as sacrificial films and mask films, these materials have high affinity with semiconductor manufacturing processes and are therefore preferred. Alternatively, oxides or nitrides of the aforementioned semiconductor materials can be used. Alternatively, non-metallic materials such as carbon or their compounds can be used. Furthermore, metals such as titanium, tantalum, tungsten, chromium, and aluminum, or alloys containing one or more of these can be used. Additionally, oxides containing the aforementioned metals, such as titanium oxide or chromium oxide, or nitrides such as titanium nitride, chromium nitride, or tantalum nitride, can be used.

[0419] By using a film containing a material with UV-blocking properties as a sacrificial film or mask film, UV radiation can be suppressed from reaching the organic compound layer, for example, during the exposure process. By suppressing UV damage to the organic compound layer, the reliability of the light-emitting device can be improved.

[0420] Note that films containing materials with UV-blocking properties also produce the same effect when used as materials for the inorganic insulating film 125f described later.

[0421] Furthermore, various inorganic insulating films can be used as both the sacrificial film 158Rf and the mask film 159Rf. In particular, oxide insulating films exhibit higher adhesion to the organic compound film 103Rf compared to nitrided insulating films, and are therefore preferred. For example, inorganic insulating materials such as alumina, hafnium oxide, or silicon oxide can be used for both the sacrificial film 158Rf and the mask film 159Rf. For example, alumina films can be formed using the ALD method for both the sacrificial film 158Rf and the mask film 159Rf. Using the ALD method can reduce damage to the substrate (especially the organic compound layer), and is therefore preferred.

[0422] For example, an inorganic insulating film (e.g., an alumina film) formed using the ALD method can be used as the sacrificial film 158Rf, 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 159Rf.

[0423] Furthermore, the same inorganic insulating film can be used for both the sacrificial layer 158Rf and the inorganic insulating layer 125 to be formed later. For example, an alumina film formed using the ALD method can be used for both the sacrificial layer 158Rf and the inorganic insulating layer 125. Here, the sacrificial layer 158Rf and the inorganic insulating layer 125 can be deposited under the same conditions or different conditions. For example, by depositing the sacrificial film 158Rf under the same conditions as the inorganic insulating layer 125, the sacrificial film 158Rf can be formed as an insulating layer with high barrier properties against at least one of water and oxygen. On the other hand, the sacrificial film 158Rf is a layer that will be mostly or entirely removed in a later process, so it is preferable to be easy to process. Therefore, the sacrificial layer 158Rf is preferably deposited under conditions with a lower substrate temperature than that of the inorganic insulating layer 125.

[0424] Organic materials can also be used as one or both of the sacrificial film 158Rf and the mask film 159Rf. For example, materials that are chemically stable in solvents that are soluble in at least the uppermost layer of the organic compound film 103Rf can also be used as organic materials. In particular, materials soluble in water or alcohol can be suitable. When depositing the above-mentioned materials, it is preferable to apply the materials by a wet deposition method while the materials are dissolved in a solvent such as water or alcohol, and then perform a heat treatment to evaporate the solvent. At this time, it is preferable to perform the heat treatment under a reduced pressure atmosphere, thereby removing the solvent at a low temperature and for a short time, and reducing the thermal damage to the organic compound film 103Rf.

[0425] Sacrificial membrane 158Rf and mask membrane 159Rf can each be made of organic resins such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerol, pullulan, water-soluble cellulose, alcohol-soluble polyamide resin or perfluoropolymer, etc.

[0426] For example, an organic film (e.g., a PVA film) formed using any one of the above-described wet deposition methods can be used as the sacrificial film 158Rf, and an inorganic film (e.g., a silicon nitride film) formed using sputtering can be used as the mask film 159Rf.

[0427] Next, as Figure 10A As shown, a resist mask 190R is formed on a mask film 159Rf. The resist mask 190R can be formed by applying a photosensitive material (photoresist) and then exposing and developing it.

[0428] The 190R resist mask can be formed using either positive or negative resist materials.

[0429] The resist mask 190R is provided at the position overlapping with the conductive layer 152R. Preferably, the resist mask 190R is also provided at the position overlapping with the conductive layer 152C. This can suppress damage to the conductive layer 152C during the manufacturing process of the display device. Note that the resist mask 190R may also be omitted from the conductive layer 152C. Additionally, as... Figure 10A As shown in the cross-sectional view along B1-B2, the resist mask 190R is preferably provided in such a way that it covers the end of the organic compound film 103Rf to the end of the conductive layer 152C (the end on the side of the organic compound film 103Rf).

[0430] Next, as Figure 10BAs shown, a portion of the mask film 159Rf is removed using a resist mask 190R to form a mask layer 159R. The mask layer 159R remains on the conductive layers 152R and 152C. Then, the resist mask 190R is removed. Next, the mask layer 159R is used as a mask (also called a hard mask) to remove a portion of the sacrificial film 158Rf to form a sacrificial layer 158R.

[0431] The sacrificial film 158Rf and the mask film 159Rf can be processed by wet etching or dry etching, respectively. The processing of the sacrificial film 158Rf and the mask film 159Rf is preferably carried out by isotropic etching.

[0432] By using wet etching, damage to the organic compound film 103Rf can be reduced during the processing of the sacrificial film 158Rf and the mask film 159Rf compared to dry etching. When using wet etching, solutions such as developer, aqueous tetramethylammonium hydroxide (TMAH), dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or mixtures thereof are preferably used.

[0433] Since the organic compound film 103Rf is not exposed during the processing of the mask film 159Rf, the range of processing methods is wider compared to the case of processing the sacrificial film 158Rf. Specifically, when processing the mask film 159Rf, even when using an oxygen-containing gas as the etching gas, the degradation of the organic compound film 103Rf can be suppressed.

[0434] Furthermore, when dry etching is used in the processing of the sacrificial film 158Rf, the degradation of the organic compound film 103Rf can be suppressed by not using an oxygen-containing gas as the etching gas. In the case of using dry etching, for example, a gas containing CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or Group 18 elements such as He is preferably used as the etching gas.

[0435] For example, when using an alumina film formed by the ALD method as the sacrificial film 158Rf, a portion of the sacrificial film 158Rf can be removed by dry etching using CHF3 and He, or CHF3, He, and CH4. Similarly, when using an In-Ga-Zn oxide film formed by sputtering as the mask film 159Rf, a portion of the mask film 159Rf can be removed by wet etching using dilute phosphoric acid. Alternatively, a portion of the mask film 159Rf can be removed by dry etching using CH4 and Ar. Furthermore, when using a tungsten film formed by sputtering as the mask film 159Rf, a portion of the mask film 159Rf can be removed by dry etching using SF6, CF4, and O2, or CF4, Cl2, and O2.

[0436] The resist mask 190R can be removed using the same method as the resist mask 191. The resist mask 190R can be removed, for example, by ashing using oxygen plasma. Alternatively, oxygen gas and Group 18 elements such as CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, or He can be used. Alternatively, the resist mask 190R can be removed by wet etching. In this case, the mask layer 159R is on the outermost surface and the organic compound film 103Rf is not exposed, so damage to the organic compound film 103Rf can be suppressed during the removal process of the resist mask 190R. Furthermore, the range of removal methods for the resist mask 190R can be expanded.

[0437] Next, as Figure 10B As shown, an organic compound film 103Rf is processed to form an organic compound layer 103R. For example, a mask layer 159R and a sacrificial layer 158R are used as a hard mask to remove part of the organic compound film 103Rf to form the organic compound layer 103R.

[0438] Therefore, as Figure 10B As shown, the conductive layer 152R has a stacked structure of organic compound layer 103R, sacrificial layer 158R, and mask layer 159R remaining on it. In addition, conductive layers 152G and 152B are exposed.

[0439] Figure 10B An example is shown where the end of the organic compound layer 103R is located inside the end of the conductive layer 152R. By employing this structure, pixel miniaturization can be achieved, enabling the fabrication of high-definition displays. Note that although in Figure 10B Not shown in the figure, but due to the above etching process, recesses are sometimes formed in the area of ​​the insulating layer 175 that does not overlap with the organic compound layer 103R.

[0440] As described above, the resist mask 190R is preferably arranged such that it covers the end of the organic compound layer 103R between the dashed lines B1-B2 and the end of the conductive layer 152C (the end on one side of the organic compound layer 103R). Thus, as... Figure 10B As shown, the sacrificial layer 158R and the mask layer 159R are disposed between the dashed lines B1-B2 in such a way that they cover the end of the organic compound layer 103R to the end of the conductive layer 152C (the end on the side of the organic compound layer 103R). Therefore, exposure of the insulating layer 175, for example, between the dashed lines B1-B2 can be suppressed. This also prevents the conductive layer 179 from being exposed due to etching or other removal of portions of the insulating layers 175, 174, and 173. Therefore, unintentional electrical connections of the conductive layer 179 to other conductive layers can be suppressed. For example, short circuits between the conductive layer 179 and the common electrode 155 to be formed in subsequent processes can be suppressed.

[0441] The organic compound film 103Rf is preferably processed using anisotropic etching. Anisotropic dry etching is particularly preferred. Alternatively, wet etching may also be used.

[0442] When using dry etching, the degradation of the organic compound film 103Rf can be suppressed by not using an oxygen-containing gas as the etching gas.

[0443] Alternatively, oxygen-containing gases can be used as etching gases. When the etching gas contains oxygen, the etching rate can be increased. Therefore, etching can be performed at low power conditions while maintaining a sufficient etching rate. This suppresses damage to the organic compound film 103Rf. Furthermore, it suppresses defects such as the adhesion of reaction products generated during etching.

[0444] When using dry etching, it is preferable to use a gas containing one or more Group 18 elements such as H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, and He or Ar as the etching gas. Alternatively, it is preferable to use a gas containing one or more of the above-mentioned gases and oxygen as the etching gas. Oxygen gas can also be used as the etching gas. Specifically, for example, a gas containing H2 and Ar or a gas containing CF4 and He can be used as the etching gas. Furthermore, for example, a gas containing CF4, He, and oxygen can be used as the etching gas. Additionally, for example, a gas containing H2 and Ar and an oxygen-containing gas can be used as the etching gas.

[0445] As described above, in one aspect of the present invention, a mask layer 159R is formed by forming a resist mask 190R on a mask film 159Rf and removing a portion of the mask film 159Rf using the resist mask 190R. Then, an organic compound layer 103R is formed by using the mask layer 159R as a mask to remove a portion of the organic compound film 103Rf. Therefore, it can be said that the organic compound layer 103R is formed by processing the organic compound film 103Rf using lithography. Alternatively, a portion of the organic compound film 103Rf can be removed using the resist mask 190R. Then, the resist mask 190R can also be removed.

[0446] Next, for example, it is preferable to perform a hydrophobic treatment on the conductive layer 152G. During the processing of the organic compound film 103Rf, the surface state of, for example, the conductive layer 152G sometimes becomes hydrophilic. By performing a hydrophobic treatment on the conductive layer 152G, for example, the adhesion between the conductive layer 152G and the layer to be formed in a later process (here, the organic compound layer 103G) can be improved, thereby suppressing film peeling. Note that a hydrophobic treatment may also be omitted.

[0447] Next, as Figure 11A As shown, an organic compound film 103Gf, which will later become an organic compound layer 103G, is formed on conductive layer 152G, conductive layer 152B, insulating layer 156R, insulating layer 156G, insulating layer 156B, mask layer 159R, and insulating layer 175.

[0448] The organic compound membrane 103Gf can be formed using the same method as that used in forming the organic compound membrane 103Rf. Furthermore, the organic compound membrane 103Gf can have the same structure as the organic compound membrane 103Rf.

[0449] Next, as Figure 11A As shown, a sacrificial film 158Gf, which will later become a sacrificial layer 158G, and a mask film 159Gf, which will later become a mask layer 159G, are sequentially formed on an organic compound film 103Gf and a mask layer 159R. Then, a photoresist mask 190G is formed. The materials and formation methods of the sacrificial film 158Gf and the mask film 159Gf are the same as those used for the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the photoresist mask 190G are the same as those used for the photoresist mask 190R.

[0450] The resist mask 190G is positioned at the location where it overlaps with the conductive layer 152G.

[0451] Next, as Figure 11B As shown, a portion of the mask film 159Gf is removed using a resist mask 190G to form a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. Then, the resist mask 190G is removed. Next, the mask layer 159G is used as part of the mask removal sacrificial film 158Gf to form a sacrificial layer 158G. Next, an organic compound film 103Gf is processed to form an organic compound layer 103G. For example, the mask layer 159G and the sacrificial layer 158G are used as part of the hard mask removal organic compound film 103Gf to form the organic compound layer 103G.

[0452] Therefore, as Figure 11B As shown, the conductive layer 152G has a stacked structure of organic compound layer 103G, sacrificial layer 158G, and mask layer 159G remaining on it. In addition, mask layer 159R and conductive layer 152B are exposed.

[0453] Next, for example, it is preferable to perform a hydrophobic treatment on the conductive layer 152B. During the processing of the organic compound film 103Gf, the surface state of, for example, the conductive layer 152B sometimes becomes hydrophilic. By performing a hydrophobic treatment on the conductive layer 152B, for example, the adhesion between the conductive layer 152B and the layer to be formed in a later process (here, the organic compound layer 103B) can be improved, thereby suppressing film peeling. Note that a hydrophobic treatment may also be omitted.

[0454] Next, as Figure 11C As shown, an organic compound film 103Bf, which will later become an organic compound layer 103B, is formed on conductive layer 152B, insulating layer 156R, insulating layer 156G, insulating layer 156B, mask layer 159R, mask layer 159G and insulating layer 175.

[0455] The organic compound membrane 103Bf can be formed using the same method as that used in forming the organic compound membrane 103Rf. Furthermore, the organic compound membrane 103Bf can have the same structure as the organic compound membrane 103Rf.

[0456] Next, as Figure 11C As shown, a sacrificial film 158Bf, which will later become a sacrificial layer 158B, and a mask film 159Bf, which will later become a mask layer 159B, are sequentially formed on an organic compound film 103Bf, a mask layer 159R, and a mask layer 159G. Then, a photoresist mask 190B is formed. The materials and formation methods of the sacrificial film 158Bf and the mask film 159Bf are the same as those used for the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the photoresist mask 190B are the same as those used for the photoresist mask 190R.

[0457] The resist mask 190B is disposed at a position overlapping the conductive layer 152B.

[0458] Next, as Figure 11D As shown, a portion of the mask film 159Bf is removed using a resist mask 190B to form a mask layer 159B. The mask layer 159B remains on the conductive layer 152B. Then, the resist mask 190B is removed. Next, the mask layer 159B is used as part of the mask removal sacrificial film 158Bf to form a sacrificial layer 158B. Next, an organic compound film 103Bf is processed to form an organic compound layer 103B. For example, the mask layer 159B and the sacrificial layer 158B are used as part of the hard mask removal organic compound film 103Bf to form the organic compound layer 103B.

[0459] Therefore, as Figure 11DAs shown, the conductive layer 152B has a stacked structure of organic compound layer 103B, sacrificial layer 158B, and mask layer 159B remaining on it. In addition, mask layer 159R and mask layer 159G are exposed.

[0460] Note that the side surfaces of organic compound layers 103R, 103G, and 103B are preferably perpendicular to or substantially perpendicular to the surface to which they are formed. For example, the angle formed between the surface to which they are formed and these side surfaces is preferably 60 degrees or more and 90 degrees or less.

[0461] As described above, the distance between two adjacent organic compound layers in the organic compound layers 103R, 103G, and 103B formed using photolithography can be reduced to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. This distance can be specified, for example, based on the distance between the opposite ends of two adjacent organic compound layers in the organic compound layers 103R, 103G, and 103B. Thus, by reducing the distance between the island-shaped organic compound layers, a display device with high resolution and high aperture ratio can be provided. Furthermore, the distance between the first electrodes of adjacent light-emitting devices can also be reduced, for example, to 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, or 2 μm or less. Preferably, the distance between the first electrodes of adjacent light-emitting devices is 2 μm or more and 5 μm or less.

[0462] Next, as Figure 12A As shown, it is preferable to remove mask layers 159R, 159G, and 159B. Depending on subsequent processes, sacrificial layers 158R, 158G, 158B, mask layers 159R, 159G, and 159B may sometimes remain in the display device. By removing mask layers 159R, 159G, and 159B at this stage, it is possible to prevent them from remaining in the display device. For example, when conductive materials are used in mask layers 159R, 159G, and 159B, by removing them beforehand, leakage current and capacitance formation due to the remaining mask layers 159R, 159G, and 159B can be suppressed.

[0463] Note that although this embodiment uses the case where mask layers 159R, 159G, and 159B are removed as an example, it is also possible to proceed with the next process without removing mask layers 159R, 159G, and 159B. For example, when mask layers 159R, 159G, and 159B contain the aforementioned material with UV-blocking properties, proceeding to the next process without removing these mask layers can protect the organic compound layer from UV radiation, which is therefore preferred.

[0464] The mask layer removal process can use the same method as the mask film processing process. In particular, by using wet etching, damage to the organic compound layers 103R, 103G, and 103B during mask layer removal can be reduced compared to using dry etching.

[0465] Alternatively, the mask layer can be removed by dissolving it in a solvent such as water or alcohol. Examples of alcohols include ethanol, methanol, isopropanol (IPA), or glycerol.

[0466] After removing the mask layer, a drying process can be performed to remove water contained in organic compound layers 103R, 103G, and 103B, as well as water adsorbed on the surfaces of organic compound layers 103R, 103G, and 103B. For example, a heating process can be performed under an inert gas atmosphere or a reduced pressure atmosphere. The heating process 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, more preferably 70°C or higher and 120°C or lower. Using a reduced pressure atmosphere allows for drying at a lower temperature, which is therefore preferred.

[0467] Next, as Figure 12B As shown, an inorganic insulating film 125f, which will later become an inorganic insulating layer 125, is formed by covering organic compound layer 103R, organic compound layer 103G, organic compound layer 103B, sacrificial layer 158R, sacrificial layer 158G, and sacrificial layer 158B.

[0468] As described later, the insulating film 127f, which will later become the insulating layer 127, is formed by contacting the top surface of the inorganic insulating film 125f. Therefore, the top surface of the inorganic insulating film 125f preferably has high affinity with the material used for the insulating film (e.g., a photosensitive resin composition containing acrylic resin). To improve this affinity, a surface treatment can be performed to hydrophobize (or improve) the top surface of the inorganic insulating film 125f. For example, a silanizing agent such as hexamethyldisilazane (HMDS) is preferably used for treatment. By hydrophobizing the top surface of the inorganic insulating film 125f in this way, the insulating film 127f can be formed with high adhesion. In addition, the above-described hydrophobic treatment can also be performed as a surface treatment.

[0469] Next, as Figure 12C As shown, an insulating film 127f, which will later become an insulating layer 127, is formed on an inorganic insulating film 125f.

[0470] The inorganic insulating film 125f and the insulating film 127f are preferably deposited by a formation method that causes less damage to the organic compound layers 103R, 103G, and 103B. In particular, the inorganic insulating film 125f is formed in contact with the sides of the organic compound layers 103R, 103G, and 103B, so the inorganic insulating film 125f is preferably deposited by a formation method that causes less damage to the organic compound layers 103R, 103G, and 103B than when the insulating film 127f is deposited.

[0471] Furthermore, the inorganic insulating film 125f and the insulating film 127f are each formed at a temperature lower than the heat resistance temperature of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. By increasing the substrate temperature during deposition, an inorganic insulating film 125f can be formed that has a low impurity concentration and high barrier properties against at least one of water and oxygen, even with a small thickness.

[0472] The substrate temperature for forming the inorganic insulating film 125f and the insulating film 127f 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.

[0473] As the inorganic insulating film 125f, it is preferable to form an insulating film with a thickness of 3 nm or more, 5 nm or more, or 10 nm or more and a thickness of 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above-mentioned substrate temperature range.

[0474] The inorganic insulating film 125f is preferably formed using the ALD method, for example. The ALD method reduces deposition damage and allows for the deposition of films with high coverage, making it preferred. For example, an alumina film is preferably formed using the ALD method as the inorganic insulating film 125f.

[0475] In addition, the inorganic insulating film 125f can also be formed using sputtering, CVD, or PECVD methods, which have higher deposition rates than ALD. This allows for the production of highly reliable display devices with high productivity.

[0476] The insulating film 127f is preferably formed using the wet deposition method described above. The insulating film 127f is preferably formed, for example, by spin coating using a photosensitive material, and more specifically, preferably by using a photosensitive resin composition containing acrylic resin.

[0477] For example, it is preferable to use a resin composition containing a polymer, an acid-generating agent, and a solvent to form the insulating film 127f. The polymer is formed using one or more monomers and has a structure in which one or more structural units (also called constituent units) are repeated regularly or irregularly. As the acid-generating agent, one or both of a compound that generates acid by irradiation and a compound that generates acid by heating can be used. The resin composition may also contain one or more of a photosensitizer, sensitizer, catalyst, adhesive aid, surfactant, and antioxidant.

[0478] Furthermore, it is preferable to perform a heat treatment (also known as pre-baking) after forming the insulating film 127f. This heat treatment is performed at a temperature lower than the heat resistance temperature of the organic compound layers 103R, 103G, and 103B. 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 removes the solvent from the insulating film 127f.

[0479] Next, exposure is performed to expose a portion of the insulating film 127f to visible light or ultraviolet light. Here, when a positive photosensitive resin composition containing acrylic resin is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto the area where the insulating layer 127 will not be formed in a later process. The insulating layer 127 is formed in the area sandwiched between any two of the conductive layers 152R, 152G, and 152B, and around the conductive layer 152C. Therefore, visible light or ultraviolet light is irradiated onto the conductive layers 152R, 152G, 152B, and 152C. Note that when a negative photosensitive material is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto the area where the insulating layer 127 will be formed.

[0480] By utilizing the area exposed to the insulating film 127f, the width of the insulating layer 127 to be formed later can be controlled. In this embodiment, the insulating layer 127 is processed such that it has a portion overlapping the top surface of the conductive layer 151.

[0481] The light used for exposure preferably has an i-line (wavelength 365 nm). Alternatively, the light used for exposure may also have at least one of a g-line (wavelength 436 nm) and an h-line (wavelength 405 nm).

[0482] Here, by providing an oxygen-blocking insulating layer (such as an alumina film) as one or both of the sacrificial layer 158 (sacrificial layer 158R, sacrificial layer 158G, and sacrificial layer 158B) and the inorganic insulating film 125f, oxygen diffusion to the organic compound layers 103R, 103G, and 103B can be suppressed. When light (visible light or ultraviolet light) irradiates the organic compound layers, the organic compounds contained in the organic compound layers may become excited and promote reaction with oxygen in the atmosphere. Specifically, when light (visible light or ultraviolet light) irradiates the organic compound layers in an oxygen-containing atmosphere, oxygen may bond to the organic compounds contained in the organic compound layers. By providing the sacrificial layer 158 and the inorganic insulating film 125f on the island-like organic compound layers, the bonding of oxygen in the atmosphere to the organic compounds contained in the organic compound layers can be suppressed.

[0483] Next, as Figure 13A As shown, the exposed areas in the insulating film 127f are removed by development to form the insulating layer 127a. The insulating layer 127a is formed in the area sandwiched by any two of the conductive layers 152R, 152G, and 152B, and in the area surrounding the conductive layer 152C. Here, when acrylic resin is used for the insulating film 127f, an alkaline solution, such as TMAH, can be used as the developing solution.

[0484] Next, residues from the development process (so-called scum) can also be removed. For example, residues can be removed by ashing using oxygen plasma.

[0485] Alternatively, etching can be performed to adjust the surface height of the insulating layer 127a. The insulating layer 127a can also be processed, for example, by ashing using oxygen plasma. Furthermore, when a non-photosensitive material is used as the insulating film 127f, the surface height of the insulating film 127f can also be adjusted, for example, by this ashing process.

[0486] Next, as Figure 13BAs shown, an etching process using insulating layer 127a as a mask removes a portion of the inorganic insulating film 125f, thereby reducing the thickness of a portion of sacrificial layers 158R, 158G, and 158B. This forms an inorganic insulating layer 125 beneath insulating layer 127a. Furthermore, the surfaces of the thinner portions of sacrificial layers 158R, 158G, and 158B are exposed. The etching process using insulating layer 127a as a mask is sometimes referred to as the first etching process.

[0487] The first etching process can be performed by dry etching or wet etching. When the inorganic insulating film 125f is deposited using the same material as the sacrificial layers 158R, 158G and 158B, the first etching process can be performed in one step, which is preferred.

[0488] By using the tapered insulating layer 127a as a mask for etching, the sides of the inorganic insulating layer 125 and the upper ends of the sides of the sacrificial layers 158R, 158G and 158B can be more easily made into a tapered shape.

[0489] When performing dry etching, chlorine-based gases are preferred. One or more of the following chlorine-based gases can be used: Cl2, BCl3, SiCl4, and CCl4. Alternatively, one or more of the following gases can be appropriately added to the chlorine-based gas: oxygen, hydrogen, helium, and argon. By utilizing dry etching, regions with thin sacrificial layers 158R, 158G, and 158B can be formed with excellent in-plane uniformity.

[0490] As a dry etching apparatus, a dry etching apparatus with a high-density plasma source can be used. For example, an inductively coupled plasma (ICP) etching apparatus can be used as a dry etching apparatus with a high-density plasma source. Alternatively, a capacitively coupled plasma (CCP) etching apparatus including parallel planar electrodes can be used. The capacitively coupled plasma etching apparatus including parallel planar electrodes can also employ a structure in which a high-frequency voltage is applied to one of the parallel planar electrodes. Alternatively, a structure in which multiple different high-frequency voltages are applied to one of the parallel planar electrodes can be used. Alternatively, a structure in which high-frequency voltages of the same frequency are applied to each of the parallel planar electrodes can be used. Alternatively, a structure in which high-frequency voltages of different frequencies are applied to each of the parallel planar electrodes can be used.

[0491] Furthermore, during dry etching, byproducts generated during the process may sometimes be deposited on the top and sides of the insulating layer 127a. As a result, components of the etching gas, the inorganic insulating film 125f, and the sacrificial layers 158R, 158G, and 158B may sometimes be included in the insulating layer 127 after the display device is completed.

[0492] Furthermore, wet etching is preferred for the first etching process. Compared to dry etching, wet etching further reduces damage to the organic compound layers 103R, 103G, and 103B. For example, wet etching can be performed using an alkaline solution. For instance, TMAH of an alkaline solution can be used in the wet etching of the alumina film. In this case, wet etching can be performed by coating. When the inorganic insulating film 125f is deposited using the same material as the sacrificial layers 158R, 158G, and 158B, the above etching process can be performed in a single step, which is therefore preferred.

[0493] In the first etching process, the sacrificial layers 158R, 158G, and 158B are not completely removed, and the etching process is stopped with a reduced thickness. Thus, by leaving corresponding sacrificial layers 158R, 158G, and 158B on the organic compound layers 103R, 103G, and 103B, damage to the organic compound layers 103R, 103G, and 103B can be prevented during subsequent processing steps.

[0494] Next, the entire substrate is preferably exposed to visible or ultraviolet light onto the insulating layer 127a. The energy density of this exposure is preferably higher than 0 mJ / cm². 2 And it is 800mJ / cm 2 Below, a value higher than 0 mJ / cm is preferred. 2 And it is 500mJ / cm 2 The following applies. By performing this exposure after development, the transparency of the insulating layer 127a can sometimes be improved. Additionally, the substrate temperature required for the subsequent heat treatment to deform the insulating layer 127a into a conical shape can sometimes be reduced.

[0495] Here, by providing oxygen-barrier insulating layers (such as an alumina film) as sacrificial layers 158R, 158G, and 158B, oxygen diffusion to the organic compound layers 103R, 103G, and 103B can be suppressed. When light (visible light or ultraviolet light) irradiates the organic compound layers, the organic compounds contained in the organic compound layers may sometimes become excited and promote reaction with oxygen in the atmosphere. Specifically, when light (visible light or ultraviolet light) irradiates the organic compound layers in an oxygen-containing atmosphere, oxygen may bond to the organic compounds contained in the organic compound layers. By providing sacrificial layers 158R, 158G, and 158B on the island-shaped organic compound layers, the bonding of oxygen in the atmosphere to the organic compounds contained in the organic compound layers can be suppressed.

[0496] Next, a heat treatment (also known as post-baking) is performed. This heat treatment deforms the insulating layer 127a into an insulating layer 127 with a tapered shape on its sides. Figure 13C The heat treatment is performed at a temperature lower than the heat resistance temperature of the organic compound layer. 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 130°C or lower. The heating atmosphere can be atmospheric or an inert gas. Alternatively, the heating atmosphere can be atmospheric or a reduced pressure atmosphere. In this heat treatment process, it is preferable to increase the substrate temperature compared to the heat treatment (pre-baking) after the formation of the insulating film 127f. This improves the adhesion between the insulating layer 127 and the inorganic insulating layer 125, and also improves the corrosion resistance of the insulating layer 127.

[0497] In the first etching process, by not completely removing the sacrificial layers 158R, 158G, and 158B, leaving a reduced thickness of the remaining sacrificial layers 158R, 158G, and 158B, damage and deterioration of the organic compound layers 103R, 103G, and 103B can be prevented during the heat treatment. This improves the reliability of the light-emitting device.

[0498] Note that, depending on the material of the insulating layer 127 and the temperature, time, and atmosphere of the post-baking process, the side surface of the insulating layer 127 may sometimes form a concave curved shape. For example, the higher the temperature or the longer the time in the post-baking conditions, the more easily the shape of the insulating layer 127 changes, thus sometimes forming a concave curved shape.

[0499] Next, as Figure 14AAs shown, the insulating layer 127 is used as a mask for etching, removing a portion of the sacrificial layers 158R, 158G, and 158B. Note that a portion of the inorganic insulating layer 125 is sometimes also removed. This creates openings in the sacrificial layers 158R, 158G, and 158B, exposing the top surfaces of the organic compound layers 103R, 103G, 103B, and the conductive layer 152C. Hereinafter, the etching process using the insulating layer 127 as a mask is sometimes referred to as the second etching process.

[0500] The ends of the inorganic insulating layer 125 are covered by the insulating layer 127. Additionally, Figure 14A An example is shown where a portion of the end of the sacrificial layer 158G (specifically, the tapered portion formed by the first etching process) is covered by the insulating layer 127 and the tapered portion formed by the second etching process is exposed.

[0501] When the inorganic insulating layer 125 and the mask layer are etched in a single process after post-baking without a first etching process, voids may sometimes form as the inorganic insulating layer 125 and the mask layer below the end of the insulating layer 127 disappear due to lateral etching. These voids create unevenness on the surface where the common electrode 155 is formed, making it prone to breakage. Even if voids are formed due to lateral etching of the inorganic insulating layer 125 and the mask layer after the first etching process, these voids can be filled by the insulating layer 127 during subsequent post-baking. Then, in the second etching process, the mask layer, with a further reduced thickness, is etched, resulting in less lateral etching, making void formation less likely, and allowing for extremely small voids. Therefore, the surface where the common electrode 155 is formed can be made flatter.

[0502] The insulating layer 127 may also cover the entire end of the sacrificial layer 158G. For example, the end of the insulating layer 127 may sometimes droop down and cover the end of the sacrificial layer 158G. Additionally, for example, the end of the insulating layer 127 may sometimes contact the top surface of at least one of the organic compound layers 103R, 103G, and 103B. As described above, the shape of the insulating layer 127 can sometimes be easily varied when the insulating layer 127a is not exposed after development.

[0503] The second etching process is performed using wet etching. Compared to dry etching, wet etching further reduces damage to the organic compound layers 103R, 103G, and 103B. Wet etching can be performed using an alkaline solution such as TMAH.

[0504] On the other hand, during the second etching process using wet etching, if gaps exist at the interfaces between the organic compound layer 103 and the sacrificial layer 158, between the organic compound layer 103 and the inorganic insulating layer 125, and between the organic compound layer 103 and the insulating layer 175 due to issues such as the adhesion between the organic compound layer 103 and other layers, the chemical solution used in the second etching process may sometimes enter these gaps and contact the pixel electrode. Here, when the chemical solution contacts both conductive layers 151 and 152, the conductive layer with the lower natural potential may sometimes corrode due to galvanic corrosion. For example, when aluminum is used as conductive layer 151 and indium tin oxide is used as conductive layer 152, conductive layer 152 may sometimes corrode. This may reduce the yield of the display device. Furthermore, it may reduce the reliability of the display device.

[0505] As described above, by forming the insulating layer 156 with a region overlapping the side of the conductive layer 151 and by forming the insulating layer 156 to cover both the conductive layer 151 and the conductive layer 152, the breakage of the inorganic insulating layer 125 can be prevented. Therefore, for example, it can prevent the solution from contacting the underlying structure such as the conductive layer 151 during the second etching process. As a result, corrosion of the pixel electrode can be prevented.

[0506] As described above, by providing insulating layer 127, inorganic insulating layer 125, sacrificial layer 158R, sacrificial layer 158G, and sacrificial layer 158B, poor connection due to disconnection and resistance rise due to localized thinner portions in the common electrode 155 can be suppressed between the light-emitting devices. Therefore, the display device according to one aspect of the present invention can improve display quality.

[0507] Alternatively, a heat treatment may be performed after a portion of the organic compound layers 103R, 103G, and 103B has been exposed. This heat treatment removes water contained in each organic compound layer and water adsorbed on the surface of each organic compound layer. Furthermore, the shape of the insulating layer 127 may sometimes change due to this heat treatment. Specifically, the insulating layer 127 may sometimes be expanded to cover at least one of the ends of the inorganic insulating layer 125, the ends of the sacrificial layers 158R, 158G, and 158B, and the top surface of the organic compound layers 103R, 103G, and 103B.

[0508] When the heat treatment temperature is too low, water contained in each organic compound layer and water adsorbed on the surface of each organic compound layer cannot be sufficiently removed. Furthermore, when the heat treatment temperature is too high, deterioration of the organic compound layer 103 and excessive deformation of the insulating layer 127 may occur. Therefore, the heat treatment temperature is preferably higher than the temperature at which water detaches from the organic compound layer 103 and lower than the glass transition temperature of the organic compounds contained in the organic compound layer 103, more preferably lower than the glass transition temperature of the organic compounds contained on the top surface of the organic compound layer 103. Specifically, the substrate temperature is preferably 80°C or higher and 130°C or lower, more preferably 90°C or higher and 120°C or lower, further preferably 100°C or higher and 120°C or lower, and even more preferably 100°C or higher and 110°C or lower. The heating atmosphere can be atmospheric or an inert gas. Note that the heating atmosphere can be atmospheric or a depressurized atmosphere; a depressurized atmosphere is preferred to prevent the re-adsorption of water detached from the organic compound layer 103.

[0509] This heat treatment can effectively remove water contained in each organic compound layer and water adsorbed on the surface of each organic compound layer without causing degradation of the organic compound layers 103R, 103G, and 103B or excessive changes in the shape of the insulating layer 127. This prevents a decline in the performance of the light-emitting device.

[0510] Next, as Figure 14B As shown, a common layer 104 and a common electrode 155 are formed on organic compound layers 103R, 103G, 103B, conductive layer 152C, and insulating layer 127. The common layer 104 and common electrode 155 can be formed by methods such as sputtering or vacuum evaporation. Alternatively, the common layer 104 can be formed by evaporation and the common electrode 155 by sputtering. Preferably, the electron injection layer structure described in Embodiment 1 is used for the common layer 104.

[0511] Next, as Figure 14C As shown, a protective layer 131 is formed on the common electrode 155. The protective layer 131 can be formed by methods such as vacuum evaporation, sputtering, CVD, or ALD.

[0512] Next, the substrate 120 is bonded to the protective layer 131 using the resin layer 122, thereby manufacturing a display device. As described above, in one embodiment of the manufacturing method of the display device according to the present invention, an insulating layer 156 is provided on the sides of the conductive layer 151 and the conductive layer 152. This improves the yield of the display device and suppresses defects.

[0513] As described above, in one embodiment of the manufacturing method of the display device of the present invention, the island-shaped organic compound layers 103R, 103G, and 103B are formed by depositing a film on one surface and then processing it, without using a high-precision metal mask. Therefore, island-shaped layers can be formed with uniform thickness. Furthermore, a high-resolution display device or a display device with a high aperture ratio can be achieved. In addition, even with high resolution or aperture ratio and extremely short distances between sub-pixels, contact between organic compound layers 103R, 103G, and 103B in adjacent sub-pixels can be suppressed. Therefore, leakage current between sub-pixels can be suppressed. Thus, crosstalk can be prevented to achieve a display device with extremely high contrast. Furthermore, a display device that exhibits good characteristics even when including tandem light-emitting devices manufactured using lithography technology can be provided.

[0514] The structure of this embodiment can be appropriately combined with the structures of other embodiments.

[0515] (Implementation Method 4)

[0516] In this embodiment, a display device according to one aspect of the present invention will be described.

[0517] The display device in this embodiment can be a high-definition display device. Therefore, for example, the display device in this embodiment can be used in the display section of information terminal devices (wearable devices) such as watch-type and bracelet-type devices, as well as in the display section of wearable devices that can be worn on the head, such as head-mounted displays (HMDs) for VR devices and glasses-type AR devices.

[0518] Furthermore, the display device of this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device of this embodiment can be used, for example, in the display section of devices such as: electronic devices with large screens, such as television devices, desktop or laptop personal computers, monitors for computers, digital signage, and large game machines such as pinball machines; digital cameras; digital video cameras; digital photo frames; mobile phones; portable game consoles; portable information terminals; and sound reproduction devices.

[0519] [Display Module]

[0520] Figure 15A A perspective view of the display module 280 is shown. The display module 280 includes a display device 100A and an FPC 290.

[0521] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display section 281. The display section 281 is the image display area in the display module 280, and can display light from each pixel disposed in the pixel section 284.

[0522] Figure 15B This is a perspective view schematically showing the structure of one side of the substrate 291. A circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked on the substrate 291. Furthermore, a terminal section 285 for connecting to the FPC 290 is provided on a portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 is electrically connected to the circuit section 282 via a wiring section 286 composed of multiple wirings.

[0523] The pixel unit 284 includes a plurality of pixels 284a arranged periodically. Figure 15B The right side shows an enlarged view of pixel 284a. Pixel 284a can adopt various structures described in the above embodiments. Figure 15B Pixel 284a is shown to have the same Figure 7A The example shown is of the same structure as pixel 178.

[0524] The pixel circuit section 283 includes a plurality of pixel circuits 283a arranged periodically.

[0525] A pixel circuit 283a controls the driving of multiple elements included in a pixel 284a. A pixel circuit 283a may contain three circuits controlling the emission of a light-emitting device. For example, the pixel circuit 283a may employ a structure that includes at least one selection transistor, one current control transistor (driving transistor), and a capacitor for each light-emitting device. In this case, the gate of the selection transistor is input with a gate signal, and the source or drain is input with a video signal. This realizes an active matrix display device.

[0526] The circuit section 282 includes circuitry for driving each pixel circuit 283a of the pixel circuit section 283. For example, it preferably includes one or both of a gate line driving circuit and a source line driving circuit. Additionally, it may include at least one of an arithmetic circuit, a storage circuit, and a power supply circuit.

[0527] The FPC290 is used for wiring to supply video signals or power potentials to the circuit section 282 from the outside. Additionally, an IC can be mounted on the FPC290.

[0528] The display module 280 can adopt a structure in which one or both of the pixel circuit section 283 and the circuit section 282 are stacked on the lower side of the pixel section 284, so that the display section 281 can have an extremely high aperture ratio (effective display area ratio). For example, the aperture ratio of the display section 281 can be 40% or more and less than 100%, preferably 50% or more and less than 95%, more preferably 60% or more and less than 95%. In addition, the pixels 284a can be arranged in an extremely high density, thereby enabling the display section 281 to have extremely high resolution. For example, the display section 281 preferably has pixels 284a arranged with a resolution of 20,000 ppi or less, or 30,000 ppi or less and more than 2,000 ppi, more preferably 3,000 ppi or more, further preferably 5,000 ppi or more, and even more preferably 6,000 ppi or more.

[0529] Due to its extremely high resolution, the display module 280 is suitable for use in VR devices such as HMDs or AR devices such as glasses. For example, because the display module 280 has a display section 281 with extremely high resolution, even when the user views the display section of the display module 280 through a lens and magnifies the display section, the pixels are not visible, thereby achieving a highly immersive display. Furthermore, not limited to this, the display module 280 can also be applied to electronic devices with relatively small display sections. For example, it is suitable for display sections in wearable electronic devices such as watch-type devices.

[0530] [Display Device 100A]

[0531] Figure 16A The display device 100A shown includes a substrate 301, light-emitting devices 130R, 130G, 130B, a capacitor 240, and a transistor 310.

[0532] Substrate 301 is equivalent to Figure 15A and Figure 15B The substrate 291 is used in the transistor 310. The transistor 310 is a transistor having a channel formation region in the substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single-crystal silicon substrate. The transistor 310 includes a portion of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 serves as the gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and serves as the gate insulating layer. The low-resistance region 312 is a region in the substrate 301 doped with impurities and serves as the source or drain. The insulating layer 314 covers the sides of the conductive layer 311.

[0533] In addition, a component separation layer 315 is provided between two adjacent transistors 310 in a manner embedded in the substrate 301.

[0534] In addition, an insulating layer 261 is provided to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0535] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 located therebetween. The conductive layer 241 is used as one electrode of the capacitor 240, the conductive layer 245 is used as the other electrode of the capacitor 240, and the insulating layer 243 is used as the dielectric of the capacitor 240.

[0536] A conductive layer 241 is disposed on an insulating layer 261 and embedded within an insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain terminals of the transistor 310 via a connector 271 embedded in the insulating layer 261. An insulating layer 243 is disposed to cover the conductive layer 241. A conductive layer 245 is disposed in the region where it overlaps with the conductive layer 241, separated by the insulating layer 243.

[0537] An insulating layer 255 is provided to cover the capacitor 240, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. Light-emitting devices 130R, 130G, and 130B are provided on the insulating layer 175. Figure 16A The light-emitting devices 130R, 130G, and 130B are shown to have Figure 1A The example shown is a stacked structure. An insulator is disposed in the region between adjacent light-emitting devices. For example, in... Figure 16A In this region, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided.

[0538] An insulating layer 156R is provided with a region overlapping the side surface of the conductive layer 151R included in the light-emitting device 130R; an insulating layer 156G is provided with a region overlapping the side surface of the conductive layer 151G included in the light-emitting device 130G; and an insulating layer 156B is provided with a region overlapping the side surface of the conductive layer 151B included in the light-emitting device 130B. Furthermore, a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R; a conductive layer 152G is provided to cover the conductive layer 151G and the insulating layer 156G; and a conductive layer 152B is provided to cover the conductive layer 151B and the insulating layer 156B. Furthermore, the sacrificial layer 158R is located on the organic compound layer 103R included in the light-emitting device 130R, the sacrificial layer 158G is located on the organic compound layer 103G included in the light-emitting device 130G, and the sacrificial layer 158B is located on the organic compound layer 103B included in the light-emitting device 130B.

[0539] Conductive layers 151R, 151G, and 151B are electrically connected to one of the source and drain terminals of transistor 310 via plugs 256 embedded in insulating layers 243, 255, 174, and 175, conductive layer 241 embedded in insulating layer 254, and plugs 271 embedded in insulating layer 261. The height of the top surface of insulating layer 175 is the same as or approximately the same as the height of the top surface of plug 256. Various conductive materials can be used for the plugs.

[0540] Additionally, 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 by a resin layer 122. Detailed descriptions of the components of the light-emitting devices 130 and the substrate 120 can be found in Embodiment 3. The substrate 120 corresponds to... Figure 15A Substrate 292.

[0541] Figure 16B Show Figure 16A A modified example of the display device 100A shown. Figure 16B The display device shown includes a color layer 132R, a color layer 132G, and a color layer 132B, and a light-emitting device 130 has a region overlapping one of the color layers 132R, 132G, and 132B. Figure 16B In the light-emitting device shown, the light-emitting device 130 can emit white light, for example. In addition, for example, the coloring layer 132R, coloring layer 132G and coloring layer 132B can transmit red light, green light and blue light, respectively.

[0542] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, in this specification, where multiple structural examples are shown in one embodiment, these structural examples can be appropriately combined.

[0543] (Implementation Method 5)

[0544] In this embodiment, an electronic device according to one aspect of the present invention will be described.

[0545] The electronic device of this embodiment includes a display device according to one aspect of the present invention in its display unit. The display device according to one aspect of the present invention has high reliability and is easily implemented with high definition and high resolution. Therefore, it can be used in the display units of various electronic devices.

[0546] As electronic devices, in addition to large-screen electronic devices such as television sets, desktop or laptop personal computers, monitors for computers, digital signage, and large game machines such as pinball machines, other examples include digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, portable information terminals, and sound reproduction devices.

[0547] In particular, because the display device of one aspect of the present invention can improve clarity, it can be suitable for use in electronic devices that include a smaller display section. Examples of such electronic devices include watch-type and bracelet-type information terminal devices (wearable devices), wearable devices that can be worn on the head, VR devices such as head-mounted displays, AR devices such as glasses, and MR devices.

[0548] The display device of one aspect of the present invention preferably has extremely high resolutions such as HD (1280×720 pixels), FHD (1920×1080 pixels), WQHD (2560×1440 pixels), WQXGA (2560×1600 pixels), 4K (3840×2160 pixels), 8K (7680×4320 pixels), etc. In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (clarity) of the display device of one aspect of the present invention is preferably 100 ppi or higher, preferably 300 ppi or higher, more preferably 500 ppi or higher, further preferably 1000 ppi or higher, even more preferably 2000 ppi or higher, even more preferably 3000 ppi or higher, still more preferably 5000 ppi or higher, and even more preferably 7000 ppi or higher. By using the aforementioned display device with one or both of high resolution and high definition, realism and depth can be further enhanced in personal electronic devices for portable or home use. Furthermore, there is no particular limitation on the screen ratio (aspect ratio) of the display device according to one aspect of the present invention. For example, the display device can accommodate various screen ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0549] The electronic device in this embodiment may also include a sensor (which has the function of measuring factors such as force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, tilt, vibration, odor, or infrared radiation).

[0550] The electronic device of this embodiment can have various functions. For example, it can have the following functions: displaying various information (static images, dynamic images, text images, etc.) on the display unit; touch panel function; displaying calendar, date, or time, etc.; executing various software (programs); wireless communication function; reading programs or data stored in the storage medium; etc.

[0551] use Figures 17A to 17DThis section describes an example of a wearable device that can be worn on the head. These wearable devices have at least one of the following functions: displaying AR content, displaying VR content, displaying SR content, and displaying MR content. When an electronic device has the function of displaying at least one of AR, VR, SR, and MR content, it can enhance the user's sense of immersion.

[0552] Figure 17A The electronic device 700A shown and Figure 17B The electronic devices 700B shown include a pair of display panels 751, a pair of frames 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical components 753, a frame 757, and a pair of nose pads 758.

[0553] The display panel 751 can be used with a display device according to one aspect of the present invention. Thus, a highly reliable electronic device can be realized.

[0554] Both electronic devices 700A and 700B can project images displayed on the display panel 751 onto the display area 756 in the optical component 753. Because the optical component 753 is translucent, the user can see the image displayed on the display area by overlapping the transmitted image seen through the optical component 753. Therefore, both electronic devices 700A and 700B are capable of AR display.

[0555] Both electronic devices 700A and 700B can be equipped with cameras capable of capturing images of the front as imaging units. Furthermore, by incorporating accelerometers such as gyroscopes into both electronic devices 700A and 700B, the orientation of the user's head can be detected, and an image corresponding to that orientation can be displayed on the display area 756.

[0556] The communications unit includes a wireless communication device through which video signals can be supplied, for example. Additionally, a connector capable of connecting cables supplying video signals and power potential may be included, either in place of the wireless communication device or in addition to the wireless communication device.

[0557] In addition, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly or via wired means, or both.

[0558] The frame 721 may also be equipped with a touch sensor module. The touch sensor module has the function of detecting whether the outer surface of the frame 721 is touched. Through the touch sensor module, various processes can be performed based on user tap or swipe operations. For example, a tap operation can temporarily pause or restart a moving image, while a swipe operation can fast forward or rewind. Furthermore, by providing a touch sensor module in each of the two frames 721, the operating range can be expanded.

[0559] Various touch sensors can be used as touch sensor modules. For example, capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, and optical sensors can be employed. In particular, capacitive or optical sensors are preferred for use in touch sensor modules.

[0560] When using optical touch sensors, photoelectric conversion devices (also known as photoelectric conversion elements) can be used as the light-receiving element. The active layer of the photoelectric conversion device can use one or both of inorganic and organic semiconductors.

[0561] Figure 17C The electronic device 800A shown and Figure 17D The electronic devices 800B shown include a pair of display units 820, a frame 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0562] The display unit 820 can be equipped with a display device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0563] The display unit 820 is located inside the housing 821 in a position visible through the lens 832. Furthermore, by displaying different images on each of the pair of display units 820, three-dimensional display utilizing parallax can be achieved.

[0564] Both electronic devices 800A and 800B can be referred to as VR-oriented electronic devices. Users who have installed electronic devices 800A or 800B can see the image displayed on the display unit 820 through the lens 832.

[0565] Electronic devices 800A and 800B preferably have a mechanism that allows adjustment of the left and right positions of the lens 832 and the display unit 820 to position them in the most suitable way according to the user's eye position. Additionally, a mechanism is preferably provided in which the focus is adjusted by changing the distance between the lens 832 and the display unit 820.

[0566] The user can use the mounting unit 823 to attach electronic device 800A or electronic device 800B to their head. For example, in Figure 17C In this case, the mounting part 823 has a shape similar to the temples (also called temple threads) of eyeglasses, but is not limited to this. As long as the user can attach it, the mounting part 823 can have a helmet-shaped or strap-shaped design, for example.

[0567] The imaging unit 825 has the function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used in the imaging unit 825. In addition, multiple cameras can be set to support various viewing angles such as telephoto and wide-angle.

[0568] Note that the example shown here includes an imaging unit 825, which can be a ranging sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object. In other words, the imaging unit 825 is one type of detection unit. For example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging) can be used as the detection unit. By using images acquired by a camera and images acquired by a distance image sensor, more information can be obtained, enabling more precise attitude control.

[0569] The electronic device 800A may also include a vibration mechanism for use as bone conduction headphones. For example, the structure including this vibration mechanism may be adopted as one or more of the display unit 820, the frame 821, and the mounting unit 823. Thus, there is no need to separately install audio equipment such as headphones, earphones, or speakers; one can enjoy images and sound simply by installing the electronic device 800A.

[0570] Electronic devices 800A and 800B may also include input terminals. For example, cables supplying image signals from image output devices and power for charging batteries installed in the electronic devices can be connected to the input terminals.

[0571] An electronic device according to one aspect of the present invention may also have the function of wirelessly communicating with the headset 750. The headset 750 includes a communication unit (not shown) and has wireless communication functionality. The headset 750 can receive information (e.g., voice data) from the electronic device via the wireless communication function. For example, Figure 17A The illustrated electronic device 700A has the function of transmitting information to the headset 750 via wireless communication. Additionally, for example... Figure 17C The electronic device 800A shown has the function of sending information to the headset 750 via wireless communication.

[0572] In addition, electronic devices may also include an earphone unit. Figure 17BThe illustrated electronic device 700B includes an earphone unit 727. For example, a structure in which the earphone unit 727 and the control unit are connected by a wire can be adopted. A portion of the wiring connecting the earphone unit 727 and the control unit can also be configured inside the housing 721 or the mounting portion 723.

[0573] same, Figure 17D The illustrated electronic device 800B includes an earphone unit 827. For example, a structure can be adopted in which the earphone unit 827 and the control unit 824 are connected by a wire. A portion of the wiring connecting the earphone unit 827 and the control unit 824 can also be disposed inside the housing 821 or the mounting portion 823. Furthermore, the earphone unit 827 and the mounting portion 823 can also include magnets. Thus, the earphone unit 827 can be magnetically secured to the mounting portion 823, making storage easy, which is preferable.

[0574] Electronic devices may also include an audio output terminal capable of connecting to headphones or headsets. Additionally, electronic devices may include one or both of an audio input terminal and an audio input mechanism. For example, a microphone or other sound-receiving device can be used as an audio input mechanism. By incorporating an audio input mechanism into the electronic device, it can be given a so-called headset function.

[0575] Thus, as an embodiment of the present invention, both eyeglass type (electronic device 700A and electronic device 700B, etc.) and goggle type (electronic device 800A and electronic device 800B, etc.) are preferred electronic devices.

[0576] In addition, one aspect of the present invention allows the electronic device to transmit information to headphones in a wired or wireless manner.

[0577] Figure 18A The electronic device 6500 shown is a portable information terminal device that can be used as a smartphone.

[0578] Electronic device 6500 includes a frame 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0579] The display unit 6502 can use a display device according to one aspect of the present invention. Therefore, a highly reliable electronic device can be realized.

[0580] Figure 18B This is a cross-sectional schematic diagram of one end of the microphone 6506, including the frame 6501.

[0581] A light-transmitting protective component 6510 is provided on one side of the display surface of the frame 6501. The space surrounded by the frame 6501 and the protective component 6510 contains a display panel 6511, an optical component 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc.

[0582] The display panel 6511, optical component 6512, and touch sensor panel 6513 are fixed to the protective component 6510 using an adhesive layer (not shown).

[0583] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and this folded portion is connected to an FPC 6515. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals disposed on a printed circuit board 6517.

[0584] The display panel 6511 can be used with a display device according to one aspect of the present invention. This allows for the realization of an extremely lightweight electronic device. Furthermore, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be installed while minimizing the thickness of the electronic device. Additionally, by folding a portion of the display panel 6511 to provide a connection portion with the FPC 6515 on the back of the pixel section, a narrow-bezel electronic device can be achieved.

[0585] Figure 18C An example of a television device is shown. In the television device 7100, a display unit 7000 is assembled in a frame 7171. The structure in which the frame 7171 is supported by a bracket 7173 is shown here.

[0586] The display unit 7000 can use a display device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0587] It can be operated using the operating switch provided in the housing 7171 and the separately provided remote control 7151. Figure 18C The operation of the television device 7100 shown is illustrated. Alternatively, a touch sensor may be provided in the display unit 7000, allowing operation of the television device 7100 by touching the display unit 7000 with a finger or the like. Furthermore, a display unit that displays information output from the remote control 7151 may be provided in the remote control 7151. Using the operation keys or touch panel provided in the remote control 7151, channel and volume can be adjusted, and the images displayed on the display unit 7000 can be manipulated.

[0588] In addition, the television device 7100 includes a receiver and a modem. It can receive general television broadcasts using the receiver. Furthermore, it can connect to a wired or wireless communication network via the modem to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0589] Figure 18D An example of a notebook computer is shown. The notebook computer 7200 includes a chassis 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214, etc. A display unit 7000 is assembled in the chassis 7211.

[0590] The display unit 7000 can use a display device according to one aspect of the present invention. This allows for the realization of a highly reliable electronic device.

[0591] Figure 18E and Figure 18F Here is an example of digital signage.

[0592] Figure 18E The digital sign 7300 shown includes a frame 7301, a display unit 7000, and a speaker 7303. It may also include LEDs, operation buttons (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0593] Figure 18F A digital sign 7400 is shown mounted on a cylindrical column 7401. The digital sign 7400 includes a display section 7000 disposed along the curved surface of the column 7401.

[0594] exist Figure 18E and Figure 18F In this embodiment, a display device according to one aspect of the present invention can be used in the display unit 7000. This allows for the realization of a highly reliable electronic device.

[0595] The larger the display unit (7000), the more information it can provide at once. A larger display unit (7000) is also more likely to attract attention, which can improve the effectiveness of advertising.

[0596] By using a touch panel in the display unit 7000, not only can static or dynamic images be displayed on the display unit 7000, but users can also operate it intuitively, making it preferable. Furthermore, when used to provide information such as route information or traffic information, intuitive operation enhances ease of use.

[0597] like Figure 18E and Figure 18FAs shown, digital signage 7300 or 7400 preferably connects wirelessly with an information terminal device 7311 or 7411, such as a smartphone carried by the user. For example, advertising information displayed on display unit 7000 can be displayed on the screen of information terminal device 7311 or 7411. Furthermore, the display on display unit 7000 can be switched by operating information terminal device 7311 or 7411.

[0598] Alternatively, the game can be executed on the digital signage 7300 or 7400 using the screen of information terminal device 7311 or 7411 as the operating unit (controller). This allows multiple users to participate in the game simultaneously and enjoy the experience.

[0599] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, in this specification, where multiple structural examples are shown in one embodiment, these structural examples can be appropriately combined.

[0600] [Example 1]

[0601] In this embodiment, light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3 of one aspect of the present invention are described. Note that light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3 are light-emitting devices manufactured by a manufacturing method that uses photolithography to process organic compound layers. The structural formulas of the organic compounds used in light-emitting device 1, light-emitting device 2, and comparative light-emitting device 3 are shown below.

[0602] [Chemical Formula 8]

[0603]

[0604] (Manufacturing method of light-emitting device 1)

[0605] First, an alloy containing silver (Ag), palladium (Pd), and copper (Cu) (APC) is deposited on a glass substrate as a reflective electrode to a thickness of 100 nm using sputtering. Then, indium tin oxide (ITSO) containing silicon oxide is deposited as a transparent electrode to a thickness of 50 nm using sputtering, thereby forming the first electrode. The electrode area is 4 mm². 2 (2mm × 2mm). In addition, the transparent electrode is used as the anode and can be combined with the above-mentioned reflective electrode to be regarded as the first electrode.

[0606] Next, as a pretreatment for forming light-emitting devices on the substrate, the substrate surface is washed with water and calcined at 200°C for 1 hour.

[0607] Then, the substrate is placed inside and depressurized to 1×10⁻⁶. -4The substrate is heated in a vacuum evaporation apparatus at approximately Pa for 30 minutes at 170°C in the heating chamber of the vacuum evaporation apparatus, and then cooled for approximately 30 minutes.

[0608] Next, the substrate is fixed in a support in a vacuum evaporation apparatus with the side having the first electrode facing down. On the first electrode, N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as: PCBiF) and an electron acceptor material (OCHD-003) with a molecular weight of 672 containing more than 4 fluorines are co-evaporated, thereby forming a hole injection layer.

[0609] PCBiF was deposited on the hole injection layer with a thickness of 95 nm to form a hole transport layer.

[0610] Next, on the hole transport layer, 8-(1,1':4',1''-triphenyl-3-yl)-4-[...

Claims

1. A light-emitting device comprising one of a plurality of light-emitting devices formed on the same insulating surface, comprising: First electrode; Second electrode; as well as Organic compound layer, Each adjacent light-emitting device independently includes the first electrode. The second electrode is shared by the adjacent light-emitting devices. The organic compound layer is located between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer and an electron injection layer. The electron injection layer is located between the light-emitting layer and the second electrode. The adjacent light-emitting devices independently include the light-emitting layer and the electron injection layer. The edge of the light-emitting layer and the edge of the electron-injecting layer are the same or approximately the same. The electron injection layer comprises a mixed layer containing a metal, a first organic compound, and a second organic compound. The first organic compound includes a phenanthroline ring having an electron-donating group. Furthermore, the second organic compound includes a π-electron-deficient heteroaromatic ring.

2. A light-emitting device comprising one of a plurality of light-emitting devices formed on the same insulating surface, comprising: First electrode; Second electrode; as well as Organic compound layer, Each adjacent light-emitting device independently includes the first electrode. The second electrode is shared by the adjacent light-emitting devices. The organic compound layer is located between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer, an electron transport layer, and an electron injection layer. The electron injection layer is located between the light-emitting layer and the second electrode. The electron transport layer is located between the light-emitting layer and the electron injection layer. The electron injection layer is shared by the adjacent light-emitting devices. The adjacent light-emitting devices independently include the light-emitting layer and the electron transport layer. The edge of the light-emitting layer and the edge of the electron-injecting layer are the same or approximately the same. The electron injection layer comprises a mixed layer containing a metal, a first organic compound, and a second organic compound. The first organic compound includes a phenanthroline ring having an electron-donating group. Furthermore, the second organic compound includes a π-electron-deficient heteroaromatic ring.

3. The light-emitting device according to claim 1 or 2, The electron-donating group is at least one of alkyl, alkoxy, aryloxy, alkylamino, arylamino, and heterocyclic amino.

4. The light-emitting device according to claim 1 or 2, The phenanthroline ring is a 1,10-phenanthroline ring, and has the electron-donating group at at least one of the 4 and 7 positions.

5. The light-emitting device according to claim 1 or 2, The acidity coefficient pKa of the first organic compound is 8 or higher.

6. A light-emitting device comprising one of a plurality of light-emitting devices formed on the same insulating surface, comprising: First electrode; Second electrode; as well as Organic compound layer, Each adjacent light-emitting device independently includes the first electrode. The second electrode is shared by the adjacent light-emitting devices. The organic compound layer is located between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer and an electron injection layer. The electron injection layer is located between the light-emitting layer and the second electrode. The adjacent light-emitting devices independently include the light-emitting layer and the electron injection layer. The edge of the light-emitting layer and the edge of the electron-injecting layer are the same or approximately the same. The electron injection layer comprises a mixed layer containing a metal, a first organic compound, and a second organic compound. The first organic compound includes a phenanthrene-rholine ring. The minimum electrostatic potential of the first organic compound is 0.0004e / a0 at the threshold of electron density distribution. 3 The time is -0.085E h the following, Furthermore, the second organic compound includes a π-electron-deficient heteroaromatic ring.

7. A light-emitting device comprising one of a plurality of light-emitting devices formed on the same insulating surface, comprising: First electrode; Second electrode; as well as Organic compound layer, Each of the adjacent light-emitting devices independently includes the first electrode. The second electrode is shared by the adjacent light-emitting devices. The organic compound layer is located between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer, an electron transport layer, and an electron injection layer. The electron injection layer is located between the light-emitting layer and the second electrode. The electron transport layer is located between the light-emitting layer and the electron injection layer. The electron injection layer is shared by the adjacent light-emitting devices. The adjacent light-emitting devices independently include the light-emitting layer and the electron transport layer. The edge of the light-emitting layer and the edge of the electron-injecting layer are the same or approximately the same. The electron injection layer comprises a mixed layer containing a metal, a first organic compound, and a second organic compound. The first organic compound includes a phenanthrene-rholine ring. The minimum electrostatic potential of the first organic compound is 0.0004e / a0 at the threshold of electron density distribution. 3 The time is -0.085E h the following, Furthermore, the second organic compound includes a π-electron-deficient heteroaromatic ring.

8. The light-emitting device according to claim 1, 2, 6 or 7, The spin density of the electron-injected layer, measured by electron spin resonance, is 5 × 10⁻⁶. 16 spins / cm 3 above.

9. The light-emitting device according to claim 8, The spin density of the mixed film containing the metal and the first organic compound, measured by electron spin resonance, is 2 × 10⁻⁶. 16 spins / cm 3 the following, Furthermore, the spin density of the mixed film containing the metal and the second organic compound, measured by electron spin resonance, is 2 × 10⁻⁶. 16 spins / cm 3 the following.

10. The light-emitting device according to claim 1, 2, 6 or 7, The second organic compound includes a phenanthrene-rhein ring.

11. The light-emitting device according to claim 1, 2, 6 or 7, The glass transition temperature of the second organic compound is above 100°C.

12. The light-emitting device according to claim 1, 2, 6 or 7, The metals mentioned therein are located in Group 1, Group 3, Group 11 or Group 13 of the periodic table.

13. A display device, comprising: The light-emitting device according to claim 1, 2, 6 or 7; as well as Transistor or substrate.

14. An electronic device comprising: The display device according to claim 13; as well as Testing department, input department, or communications department.

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