Light emitting device and light emitting apparatus

Abstract

Provided is a light-emitting device having good reliability. There is provided a light-emitting device including a first electrode, a second electrode, and a light-emitting layer between the first electrode and the second electrode, the light-emitting layer including a light-emitting layer and an electron injection layer, the electron injection layer including a metal oxide and a first organic compound, and the electron injection layer including a second organic compound. The first organic compound is an organic compound containing a phenanthroline ring having an electron-donating group.

Description

Technical Field

[0001] One aspect of the present invention relates to a light-emitting device and a light-emitting apparatus.

[0002] Note that one aspect of the present invention is not limited to the technical fields described above. Examples of technical fields encompassing one aspect of the present invention include semiconductor devices, display devices, light-emitting devices, energy storage devices, memory devices, electronic devices, lighting devices, input devices (e.g., touch sensors), input / output devices (e.g., touch panels), and driving or manufacturing methods for the aforementioned devices. Background Technology

[0003] In recent years, display devices have been applied to various purposes. For example, as large display devices, research and development is underway for home television devices (also known as televisions or television receivers), digital signage, and public information displays (PIDs). As small display devices, research and development is underway for smartphones or tablets with touch panels.

[0004] At the same time, efforts are being made to upgrade display devices to higher resolutions. Research and development is underway for devices requiring high-resolution displays, such as those for Virtual Reality (VR), Augmented Reality (AR), Substitutional Reality (SR), and Mixed Reality (MR).

[0005] As display elements used in display devices, the development of light-emitting devices (also known as light-emitting elements) is increasingly active. Light-emitting devices (also known as EL devices or EL elements) that utilize the electroluminescence (EL) phenomenon, especially organic EL devices that mainly use organic compounds, have the following characteristics: they are easy to achieve in thin and lightweight form; they can respond to input signals at high speed; and they can be driven by a DC constant voltage power supply, etc., so they are preferred for use in display devices.

[0006] To obtain higher-resolution light-emitting devices using organic EL devices, techniques for patterning organic layers using photolithography with photoresists or similar methods instead of evaporation using metal masks have been investigated. By using photolithography, high-resolution display devices with EL layer spacing of a few μm can be obtained (see, for example, Patent Document 1).

[0007] [Preliminary Technology Documents] [Patent Literature] [Patent Document 1] Japanese PCT International Application Translation No. 2018-521459 [Patent Document 2] International Patent Application Publication No. 2021 / 045178. Summary of the Invention

[0008] The technical problem that the invention aims to solve It is known that the initial properties or reliability of the EL layer in organic EL devices are affected when exposed to atmospheric components such as water and oxygen. Common practice is to process the EL layer in a near-vacuum atmosphere. In particular, alkali metals or alkaline earth metals or their compounds are used in the electron injection layer. These metals and compounds are highly reactive with water or oxygen. When the surface of the EL layer is exposed to the atmosphere, the electron injection layer deteriorates rapidly and loses its function as an electron injection layer.

[0009] However, in the process of processing using photolithography, the surface of the EL layer must be exposed to the atmosphere.

[0010] One objective of this invention is to provide a novel light-emitting device. Another objective is to provide a light-emitting device with good luminous efficiency. Yet another objective is to provide a light-emitting device with high reliability. Finally, one objective is to provide a light-emitting device with both good luminous efficiency and high reliability.

[0011] Furthermore, one objective of this invention is to provide a novel light-emitting device manufactured through a photolithography process. Another objective of this invention is to provide a light-emitting device with good luminous efficiency manufactured through a photolithography process. Another objective of this invention is to provide a light-emitting device with good reliability manufactured through a photolithography process. Finally, one objective of this invention is to provide a light-emitting device with both good luminous efficiency and high reliability manufactured through a photolithography process.

[0012] Furthermore, one objective of this invention is to provide a novel light-emitting device that can be used in high-definition light-emitting devices. Another objective of this invention is to provide a light-emitting device with good efficiency that can be used in high-definition light-emitting devices. Another objective of this invention is to provide a light-emitting device with good reliability that can be used in high-definition light-emitting devices. Finally, one objective of this invention is to provide a light-emitting device with good luminous efficiency and reliability that can be used in high-definition light-emitting devices.

[0013] Furthermore, one objective of this invention is to provide a highly reliable light-emitting device. Another objective of this invention is to provide a high-definition light-emitting device. Finally, one objective of this invention is to provide a light-emitting device that is both high-definition and highly reliable.

[0014] Note that the description of these objectives does not preclude the existence of other objectives. One aspect of the invention does not require achieving all of the above objectives. Objectives other than those described above can be extracted from the specification, drawings, and claims.

[0015] means of solving technical problems One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, and an organic compound layer, wherein the organic compound layer is located between the first electrode and the second electrode, the organic compound layer comprising a light-emitting layer and an electron injection layer, the electron injection layer being a mixed layer of a metal oxide and a first organic compound, and the first organic compound being an organic compound containing a phenanthroline ring having an electron-donating group.

[0016] Another aspect of the present invention is a light-emitting device, which is one of a plurality of light-emitting devices included in a group of light-emitting devices. The group of light-emitting devices includes a first electrode group formed on the same insulating surface, a second electrode opposite to the first electrode group, and a first layer group located between the first electrode group and the second electrode. The light-emitting device includes a first electrode, a second electrode, and a first layer, wherein the first electrode is one of the first electrode group and is independent in each of the plurality of light-emitting devices, the first layer is one of the first layer group and is independent in each of the plurality of light-emitting devices, the second electrode is a continuous conductive layer shared by the plurality of light-emitting devices, the second electrode and the first layer overlap with the first electrode, the first layer includes a light-emitting layer and an electron injection layer, the electron injection layer is a mixed layer of metal oxide and a first organic compound, the first organic compound is an organic compound containing a phenanthroline ring having an electron-donating group, and the spacing between the first layer in the light-emitting device and the first layer in other light-emitting devices adjacent to the light-emitting device is 0.5 μm or more and 5 μm or less.

[0017] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the metal oxide is an oxide comprising any element from Group 1, Group 2, Group 3, Group 11 and Group 13.

[0018] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein when the threshold value of the electron density distribution in the atomic unit system is 0.0004, the minimum value of the electrostatic potential of the first organic compound is -0.085 or less.

[0019] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the metal oxide is an oxide comprising any element from Group 1, Group 2, Group 3, Group 11 and Group 13.

[0020] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the phenanthroline ring is a 1,10-phenanthroline ring and has an electron-donating group at at least one of the 4 and 7 positions.

[0021] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the electron-donating group is one or more of alkyl, alkoxy, aryloxy, alkylamino, arylamino, and heterocyclic amino groups.

[0022] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the phenanthroline ring is a 1,10-phenanthroline ring and has an electron-donating group at at least one of the 4 and 7 positions, and the electron-donating group is one or more of alkyl, alkoxy, aryloxy, alkylamino, arylamino, and heterocyclic amino groups.

[0023] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the acidity coefficient pKa of the first organic compound is 8 or higher.

[0024] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the electron injection layer further comprises a second organic compound.

[0025] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the second organic compound is an organic compound containing a π-electron-deficient heteroaromatic ring.

[0026] In addition, another aspect of the present invention is a light-emitting device having the above-described structure, wherein the glass transition temperature of the second organic compound is above 100°C.

[0027] Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the spin density of the electron injection layer, measured using the electron spin resonance method, is 5 × 10⁻⁶. 16 spins / cm 3 above.

[0028] Another aspect of the present invention is a light-emitting device having the above-described structure, further comprising a hole injection layer located between the first electrode and the light-emitting layer, the hole injection layer comprising a third organic compound having hole transport properties and a first substance having acceptor properties to the third organic compound. Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the hole injection layer comprises a third organic compound having hole transport properties and an organic compound having at least four of the following groups: halogen groups and cyano groups. Another aspect of the present invention is a light-emitting device having the above-described structure, wherein the hole injection layer comprises a third organic compound having hole transport properties and a metal oxide different from the metal oxide contained in the electron injection layer.

[0029] Another aspect of the present invention is a light-emitting device in which the spin density of the hole injection layer, measured using the electron spin resonance method, is 1 × 10⁻⁶. 17 spins / cm 3 above.

[0030] Another aspect of the present invention is a light-emitting device comprising a plurality of light-emitting devices, wherein each of the plurality of light-emitting devices is any of the aforementioned light-emitting devices, each of the plurality of light-emitting devices comprises an organic compound layer, the organic compound layer comprising a light-emitting layer and an electron injection layer located between a first electrode and a second electrode, and the organic compound layer comprised in each of the plurality of light-emitting devices is independent among the plurality of light-emitting devices.

[0031] Another aspect of the present invention is a display module that includes the above-described light-emitting device, as well as at least one of a connector and an integrated circuit.

[0032] Another aspect of the present invention is an electronic device comprising the aforementioned light-emitting device and at least one of a housing, a battery, a camera, a speaker, and a microphone.

[0033] Invention Effects According to one aspect of the present invention, a novel light-emitting device can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device with good luminous efficiency can be provided. Additionally, according to one aspect of the present invention, a light-emitting device with good reliability can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device with both good luminous efficiency and good reliability can be provided.

[0034] Furthermore, according to one aspect of the present invention, a novel light-emitting device manufactured through a photolithography process can be provided. Additionally, according to one aspect of the present invention, a light-emitting device with good luminous efficiency manufactured through a photolithography process can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device with good reliability manufactured through a photolithography process can be provided. Additionally, according to one aspect of the present invention, a light-emitting device with both good luminous efficiency and high reliability manufactured through a photolithography process can be provided.

[0035] Furthermore, according to one aspect of the present invention, a novel light-emitting device for use in high-definition display devices can be provided. Additionally, according to one aspect of the present invention, a light-emitting device with good luminous efficiency for use in high-definition display devices can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device with good reliability for use in high-definition display devices can be provided. Additionally, according to one aspect of the present invention, a light-emitting device with both good luminous efficiency and reliability for use in high-definition display devices can be provided.

[0036] Furthermore, according to one aspect of the present invention, a highly reliable display device can be provided. Additionally, according to one aspect of the present invention, a high-definition display device can be provided. Furthermore, according to one aspect of the present invention, a display device that is both high-definition and highly reliable can be provided.

[0037] In addition, according to one aspect of the present invention, a novel organic compound, a novel light-emitting device, a novel display device, a novel display module, and a novel electronic 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 Figure 1A and Figure 1B This is a diagram showing a light-emitting device.

[0040] Figure 2A and Figure 2B This is a diagram showing a light-emitting device.

[0041] Figure 3A and Figure 3B These are top views and cross-sectional views of the light-emitting device.

[0042] Figures 4A to 4E This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0043] Figure 5A and Figure 5BThis is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0044] Figures 6A to 6D This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0045] Figures 7A to 7C This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0046] Figures 8A to 8C This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0047] Figures 9A to 9C This is a cross-sectional view illustrating an example of a manufacturing method for a display device.

[0048] Figure 10A and Figure 10B This is a perspective view showing an example of the structure of a display module.

[0049] Figure 11A and Figure 11B This is a cross-sectional view showing an example of the structure of a display device.

[0050] Figure 12 This is a perspective view showing an example of the structure of a display device.

[0051] Figure 13 This is a cross-sectional view showing an example of the structure of a display device.

[0052] Figure 14 This is a cross-sectional view showing an example of the structure of a display device.

[0053] Figure 15 This is a cross-sectional view showing an example of the structure of a display device.

[0054] Figures 16A to 16D This is a diagram illustrating an example of an electronic device.

[0055] Figures 17A to 17F This is a diagram illustrating an example of an electronic device.

[0056] Figures 18A to 18G This is a diagram illustrating an example of an electronic device.

[0057] Figure 19 This is a graph showing the XPS measurement results of an indium-doped organic film (sample 1-1) and an indium oxide (In2O3)-doped organic film (sample 1-2).

[0058] Figure 20 This is a diagram showing the brightness-current density characteristics of light-emitting device 1, light-emitting device 2, and a comparison of light-emitting device 1.

[0059] Figure 21This is a diagram showing light-emitting device 1, light-emitting device 2, and comparing the brightness-voltage characteristics of light-emitting device 1.

[0060] Figure 22 This is a graph showing the current efficiency-current density characteristics of light-emitting device 1, light-emitting device 2, and comparison of light-emitting device 1.

[0061] Figure 23 This is a graph showing the current density-voltage characteristics of light-emitting device 1, light-emitting device 2, and a comparison of light-emitting device 1.

[0062] Figure 24 This is a diagram showing the electroluminescence spectra of light-emitting device 1, light-emitting device 2, and comparative light-emitting device 1.

[0063] Figure 25 This is a graph showing the brightness-current density characteristics of light-emitting device 3, light-emitting device 4, and comparative light-emitting device 2.

[0064] Figure 26 This is a diagram showing the brightness-voltage characteristics of light-emitting device 3, light-emitting device 4, and comparative light-emitting device 2.

[0065] Figure 27 This is a graph showing the current efficiency-current density characteristics of light-emitting device 3, light-emitting device 4, and comparative light-emitting device 2.

[0066] Figure 28 This is a graph showing the current density-voltage characteristics of light-emitting device 3, light-emitting device 4, and comparative light-emitting device 2.

[0067] Figure 29 This is a graph showing the electroluminescence spectra of light-emitting device 3, light-emitting device 4, and comparative light-emitting device 2.

[0068] Figure 30A and Figure 30B This is a diagram showing a light-emitting device.

[0069] Methods of implementing the invention 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 only to the contents described in the embodiments shown below.

[0070] Note that in this specification, etc., devices manufactured using metal masks or FMMs (Fine Metal Masks) are sometimes referred to as devices with MM (Metal Mask) structures. Furthermore, in this specification, etc., devices manufactured without metal masks or FMMs are sometimes referred to as devices with MML (Metal Mask Less) structures.

[0071] (Implementation Method 1) Vacuum evaporation (VEA), using metal masks, is widely employed as one method for forming organic semiconductor films into predetermined shapes. However, recent advancements in density and resolution have pushed VEA to its limits due to various issues, including problems with alignment accuracy and substrate spacing. On the other hand, there is a desire to achieve organic semiconductor devices with denser patterns by processing the shape of organic semiconductor films using photolithography. Furthermore, photolithography is easier to scale up compared to VEA, therefore research on processing organic semiconductor films using photolithography is ongoing.

[0072] On the other hand, it is known that the EL layer in organic EL devices is affected by exposure to atmospheric components such as water and oxygen, which can impact initial characteristics or reliability. Therefore, processing is typically performed in a near-vacuum atmosphere.

[0073] In particular, the electron injection layer of light-emitting devices often uses alkali metals or alkaline earth metals or their compounds (hereinafter also referred to as Li compounds, etc.). However, these Li compounds are highly reactive with water or oxygen and will deteriorate rapidly when exposed to the atmosphere, thus losing their function as an electron injection layer.

[0074] However, during the aforementioned photolithography process, the surface of the EL layer is inevitably exposed to the atmosphere. Therefore, photolithography significantly reduces the electron injection capability of electron injection layers using alkali metal compounds. Consequently, organic EL devices fabricated using photolithography, including those with electron injection layers using alkali metal compounds, experience increased driving voltages, making it difficult to achieve optimal characteristics.

[0075] Because alkali metal compounds used in electron injection layers are highly reactive, they are sensitive to reactions during processes involving exposure to the atmosphere, leading to degradation. Considering the above reasons, the following method is proposed: if a less reactive substance can be used to replace alkali metal compounds, the rise in driving voltage can be suppressed even when processing is performed using photolithography.

[0076] Compared to alkali metal compounds, most metal oxides (excluding alkali metal oxides) are more stable and therefore easier to handle. Furthermore, due to their stability, metal oxides are relatively less prone to degradation even when exposed to the atmosphere. However, precisely because of their stability, it is difficult to obtain the same properties as alkali metal compounds in existing light-emitting devices when replacing the electron injection layer with them, thus hindering the development of practical organic EL devices.

[0077] Here, the inventors discovered that by replacing the electron injection layer with a layer comprising a metal oxide and an organic compound containing a phenanthroline ring having an electron-donating group, an organic EL device with good characteristics can be realized even when performing a photolithography process that exposes the EL layer to the atmosphere.

[0078] In other words, by replacing the electron injection layer with a mixed layer of an organic compound (the first organic compound) containing an electron-donating phenanthroline ring and a metal oxide, an organic EL device with good characteristics can be obtained even if a photolithography process that exposes the EL layer to the atmosphere is performed.

[0079] This is because by including a phenanthroline ring in the first organic compound, which readily interacts with metals, and having an electron-donating group, the electron density of the phenanthroline ring increases, and it can even interact with stable metal oxides, making it a donor for adjacent electron transport materials.

[0080] Furthermore, the interaction between the metal oxide and the first organic compound forms donor levels (Singly Occupied Molecular Orbital (SOMO) or Highest Occupied Molecular Orbital (HOMO) levels). This lowers the electron injection barrier to the electron transport layer.

[0081] Furthermore, as mentioned above, since metal oxides are relatively stable, even if the organic EL device of one aspect of the present invention is manufactured using a photolithography method that exposes the EL layer to the atmosphere, it is possible to achieve an organic EL device with characteristics that are comparable to those of an organic EL device manufactured without exposure to the atmosphere (i.e., manufactured using a so-called continuous vacuum process).

[0082] Thus, by using a metal oxide and a first organic compound as the electron injection layer, an electron injection layer resistant to atmospheric oxygen and water, as well as water and chemicals used in the photolithography process, can be formed. Therefore, one aspect of the present invention can provide an organic EL device with low driving voltage and high luminous efficiency, exhibiting high moisture resistance, high water resistance, high oxygen resistance, and high chemical resistance. As a result, a high-resolution organic EL device with excellent characteristics can be provided using photolithography.

[0083] Furthermore, the electron injection layer, comprising a metal oxide and an organic compound containing a phenanthroline ring with an electron-donating group (the first organic compound), is preferably a mixed layer of the metal oxide and the first organic compound. When the electron injection layer is a mixed layer of the metal oxide and the first organic compound, a tandem organic EL device with equally good characteristics can be achieved regardless of whether it is manufactured using a continuous vacuum process or an atmospheric exposure process. Additionally, compared to a stacked structure, using a mixed layer results in fewer layers, higher productivity, and facilitates mass production.

[0084] Furthermore, unlike oxides of other metals, alkali metals or alkaline earth metals such as lithium oxide (Li₂O) exhibit good characteristics in organic EL devices manufactured using continuous vacuum processes when used as the electron injection layer. However, as mentioned above, in the case of photolithography processes that expose the EL layer to the atmosphere, even in tandem organic EL devices using alkali metal or alkaline earth metal oxides as the electron injection layer, the driving voltage increases significantly compared to organic EL devices manufactured using continuous vacuum processes. This is because, as mentioned above, the donor properties of alkali metal or alkaline earth metal oxides deteriorate when exposed to the atmosphere.

[0085] In one aspect of the present invention, by using an oxide of an alkali metal or alkaline earth metal and an organic compound (first organic compound) containing a phenanthroline ring having an electron-donating group as an electron injection layer such as lithium oxide (Li2O), organic EL devices that have the same good properties as organic EL devices manufactured by a photolithography process exposed to the atmosphere can be obtained even if the organic EL device is manufactured by a continuous vacuum process.

[0086] This is due to the following reason: by using oxides of alkali metals and alkaline earth metals and a first organic compound containing an electron-donating phenanthroline ring in the electron injection layer, donor levels (SOMO or HOMO levels) are formed through interaction. Because of their high energy levels, the electron injection barrier to the electron transport layer is lowered, allowing electrons to be smoothly injected and transported to the electron transport layer. Therefore, even when exposed to the atmosphere, a tandem organic EL device with good characteristics can be achieved by suppressing the rise in driving voltage.

[0087] Thus, an organic EL device according to one aspect of the present invention, using an electron injection layer comprising a metal oxide and an organic compound (a first organic compound) containing a phenanthroline ring having an electron-donating group, can achieve organic EL devices with good characteristics even after a process of exposing the EL layer to the atmosphere. In other words, by using the structure of one aspect of the present invention, an organic EL device with good characteristics can be fabricated using a photolithography method that includes a process of exposing the EL layer to the atmosphere. Therefore, an ultra-high resolution light-emitting device with good characteristics can be provided.

[0088] Alternatively, when forming the electron-injected layer, metal monomers can be deposited instead of metal oxides, and the electron-injected layer can be formed by oxidizing the metal monomers. For example, metal oxides can be formed by oxidizing the metal monomers during a deposition process, a process of exposure to the atmosphere during the manufacturing process, or a process of treatment in an atmosphere containing oxygen, such as the atmosphere (heat treatment, etc.). Figure 19 The use of a vacuum evaporation apparatus at 1×10 -4 XPS (X-ray Photoelectron Spectroscopy) measurements of indium-doped organic films (sample 1-1) and indium oxide-doped organic films (sample 1-2) under reduced pressure of approximately Pa using a co-evaporation method.

[0089] Sample 1-1 was prepared by depositing 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (mPPhen2P), 4,7-di-1-pyrrolidinyl-1,10-phenanthroline (Pyrrd-Phen), and indium on a quartz substrate at a volume ratio of 0.5:0.5:0.1 (mPPhen2P:Pyrrd-Phen:In) with a thickness of 50 nm. Sample 1-2 was prepared by depositing mPPhen2P, Pyrrd-Phen, and indium oxide (In2O3) on a quartz substrate at a volume ratio of 0.5:0.5:0.1 (mPPhen2P:Pyrrd-Phen:In2O3) with a thickness of 50 nm.

[0090] Figure 19 This is the In3d5 / 2 spectrum of indium. The measurement results of samples 1-1 and 1-2 are basically overlapping, and there is no difference in the state of indium in these two samples. The waveform analysis results of this spectrum are shown below. It can be seen that almost all the indium in this sample exists in the form of indium oxide.

[0091] [Table 1] As described above, even if the electron injection layer is deposited using a monomer of the metal instead of a metal oxide, the metal will be oxidized and become a metal oxide, so an organic EL device of one aspect of the present invention can still be realized.

[0092] As described above, by including a metal oxide and an organic compound containing a phenanthroline ring with an electron-donating group (the first organic compound) in the electron injection layer, even tandem organic EL devices manufactured through processes exposed to the atmosphere can easily obtain good characteristics.

[0093] As described above, the electron injection layer is a layer disposed in the EL layer in contact with the electron transport layer and the cathode, and it includes a metal oxide and an organic compound (first organic compound) containing a phenanthroline ring having an electron-donating group. In addition to the metal oxide and the organic compound (first organic compound) containing a phenanthroline ring having an electron-donating group, the electron injection layer may also include a second organic compound.

[0094] <Metal Oxides> As metal oxides in the electron injection layer, oxides containing the following elements can be used: alkali metals such as Li (Group 1 elements); alkaline earth metals such as Mg and Ca (Group 2 elements); Group 3 elements containing lanthanides such as Y, Eu, and Yb; Group 11 elements such as Cu, Ag, and Au; earth metals such as Al and In (Group 13 elements); and Group 14 elements such as Sn.

[0095] The metal oxides are preferably oxides of alkali metals and alkaline earth metals, so that the donor level formed by the interaction with the first organic compound can be a high energy level, and electrons can be smoothly injected and transported to the electron transport layer, thereby providing a light-emitting device with low driving voltage and high efficiency. In addition, the metal oxides are preferably oxides of transition metals, because they have low reactivity with components such as water and oxygen in the atmosphere and are more stable. Among the above materials, metal oxides containing elements belonging to odd groups of the periodic table (Group 1, Group 3, Group 11 or Group 13) are preferred, because they readily form donor levels with the first organic compound.

[0096] Furthermore, metals or metal oxides with low melting points that can be deposited using vacuum evaporation are preferred, thereby facilitating the formation of mixed or stacked layers with organic compounds. Specifically, for example, metals and metal oxides of Group 11 and Group 13 elements have low melting points, making them suitable for vacuum evaporation. Additionally, metals and metal oxides of Group 11 and Group 13 elements are stable to atmospheric oxygen and water, and are therefore preferred. As for the metals or metal oxides that can be deposited using vacuum evaporation, their melting point at atmospheric pressure is preferably below 2000°C, below 1500°C, and more preferably below 1000°C, or their sublimation temperature under reduced pressure (vacuum of 1 Pa or less) is preferably below 1500°C, below 1000°C, and more preferably below 500°C.

[0097] Specifically, the metal oxide can be, for example, lithium oxide, magnesium oxide, calcium oxide, silver oxide, indium oxide, etc. As mentioned above, metal monomer materials that are oxidized into metal oxides during processes such as deposition or exposure to the atmosphere can also be used. Specifically, the metal material can be, for example, lithium, magnesium, calcium, ytterbium, silver, aluminum, indium, etc.

[0098] <First Organic Compound> An organic compound containing a phenanthroline ring can be used as the first organic compound included in the electron-injection layer. More preferably, an organic compound containing a phenanthroline ring having an electron-donating group is used as the first organic compound, thereby increasing the electron density of the phenanthroline ring.

[0099] Furthermore, organic compounds containing a 1,10-phenanthroline ring in the phenanthroline ring are particularly preferred because they contain two nitrogen atoms at positions where they are readily coordinated with metal oxides, which facilitates their interaction with metal oxides.

[0100] When an electron-donating group is introduced into the 1,10-phenanthroline ring, the electron-donating group is preferably substituted at the 4 and 7 positions of the 1,10-phenanthroline ring. By introducing electron-donating groups at the 4 and 7 positions of the 1,10-phenanthroline ring, the electron density of the nitrogen atoms at the 1 and 10 positions can be increased, thereby facilitating interaction with metal oxides.

[0101] 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.

[0102] Specific examples of alkyl groups that can be used as the aforementioned electron-donating 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, and 2,3-dimethylbutyl.

[0103] Specific examples of alkoxy groups that can be used as the aforementioned electron-donating 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.

[0104] Specific examples of aryloxy groups that can be used as electron-donating groups include phenoxy, o-tolyloxy, m-tolyloxy, p-tolyloxy, mesitylexyloxy, o-biphenyloxy, m-biphenyloxy, p-biphenyloxy, 1-naphthyloxy, 2-naphthyloxy, and 2-fluorenyloxy. Aryloxy groups may also have substituents; specific examples of such substituents include alkyl, alkoxy, and phenyl groups.

[0105] Specific examples of alkylamino groups that can be used as electron-donating groups include dimethylamino, diethylamino, etc.

[0106] Specific examples of aryl amino groups that can be used as electron-donating groups include diphenylamino, bis(α-naphthyl)amino, and bis(m-tolyl)amino. Arylamino groups can also have substituents; specific examples of such substituents include alkyl, alkoxy, and phenyl groups.

[0107] Specific examples of heterocyclic amino groups that can be used as electron-donating groups include those shown in structural formulas (R-1) to (R-26). Note that heterocyclic amino groups may also have substituents, and specific examples of such substituents include alkyl, alkoxy, and phenyl groups.

[0108] [Chemical Formula 1] Furthermore, the 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 them, the groups represented by structural formulas (R-3), (R-4), (R-8), or (R-21) have high electron-donating properties, which can further increase the electron density of the phenanthroline ring, and are therefore particularly preferred.

[0109] In addition, as specific examples of electron-donating groups, the groups shown in the following structural formulas (R-27) and (R-28) can be cited.

[0110] [Chemical Formula 2] Note that organic compounds containing a phenanthroline ring that can be used as the first organic compound may also have both the aforementioned electron-donating group and other substituents. Specific examples of substituents that can be introduced into the phenanthroline ring other than the aforementioned electron-donating group 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 may also have substituents; specific examples of such substituents include alkyl, alkoxy, phenyl, etc.

[0111] Structural formulas (100) to (107) show specific examples of organic compounds containing a phenanthroline 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.

[0112] [Chemical Formula 3] Furthermore, when the negative minimum value of the electrostatic potential (ESP) of the first organic compound is small (the absolute value of the negative value is large), it is easier for it to interact with the metal oxide, so this is preferred.

[0113] In organic compounds containing phenanthroline rings, the electrostatic potential around the nitrogen atom of the phenanthroline ring tends to become negative. By introducing electron-donating groups into the phenanthroline ring, the electrostatic potential around the nitrogen atom of the phenanthroline ring can be further reduced (increasing the absolute value of the negative value).

[0114] 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 electrostatic potential varies depending on a threshold electron density.

[0115] In order to facilitate interaction with metal oxides, the minimum electrostatic potential of the first organic compound is preferably less than (greater than) the minimum electrostatic potential of the phenanthroline ring without substituents.

[0116] Specifically, when the threshold for electron density distribution in atomic units is 0.0004e / a0 3 (e represents the elementary charge (1e = 1.60218 × 10⁻⁶)) -19C), a0 represents the Bohr radius (1a0 = 5.29177 × 10⁻⁶). -11 When m), the minimum electrostatic potential of the first organic compound 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 in the atomic unit system is 0.003e / a0 3 At that time, the minimum electrostatic potential of the first organic compound is preferably -0.12E. h Hereinafter, -0.13E is preferred. h Below. Additionally, when the threshold for electron density distribution in the atomic unit system is 0.0004e / a0 3 At that time, the minimum value of the ESP of the first organic compound is preferably -0.085E. h More preferably, when the threshold for the electron density distribution in the atomic unit system is 0.003e / a0 3 The minimum value is -0.12E. h .

[0117] The minimum electrostatic potential (ESP) of the organic compounds shown in the above-described structural formulas (101) to (107), Bphen, mPPhen2P, NBphen, Phen, and Hid2Phen, which are applicable to the first organic compound, was estimated using quantum chemical calculations. The structural formulas of the organic compounds shown in structural formulas (101) to (107), Bphen, mPPhen2P, NBphen, Phen, and Hid2Phen are shown below.

[0118] [Chemical Formula 4] Gaussian09 was used as the quantum chemical calculation program. The calculations were performed using an SGI8600 from HPE. The most stable structure of the first organic compound in its ground state was calculated using density functional theory (DFT). 6-311G(d,p) was used as the basis function, and B3LYP was used as the functional.

[0119] Table 2 shows the analytical results of the electrostatic potential of the first organic compound in its ground state. Note that electrostatic potential refers to the interaction energy between a positive point charge of unit charge and the electron distribution of the molecule. Furthermore, the value of the electrostatic potential varies depending on the threshold of the electron density. Table 2 shows the threshold for the electron density distribution in atomic units as 0.0004e / a0. 3Or 0.003e / a0 3 Electrostatic potential in the electron density distribution of the atomic unit system of time.

[0120] [Table 2] As shown in the table above, the threshold for electron density distribution in the atomic unit system is 0.0004e / a0. 3 At that time, the minimum ESP value of the organic compounds represented by structural formulas (100) to (103) and Hid2Phen was -0.085E. h The following are more suitable for use as the first organic compound. Additionally, when the threshold for electron density distribution in the atomic unit system is 0.003e / a0 3 At that time, the minimum ESP value of the organic compounds represented by structural formulas (100) to (103) was -0.12E. h The following are more suitable for use as the first organic compound.

[0121] This is due to the following reason: the organic compounds shown in structural formulas (100) to (103) and Hid2Phen introduce electron-donating groups at the 4 and 7 positions of the 1,10-phenanthroline ring, thereby providing high electron donation to the nitrogen at the 1 and 10 positions of the phenanthroline ring.

[0122] Furthermore, when the threshold for electron density distribution in the atomic unit system is 0.0004e / a0 3 At that time, the minimum ESP value of the organic compounds represented by structural formulas (101) and (103) and Hid2Phen was -0.090E. h The following is particularly suitable for use as a first organic compound. Additionally, when the threshold for electron density distribution in the atomic unit system is 0.003e / a0 3 At that time, the minimum ESP value of the organic compound represented by structural formula (103) was -0.13E. h The following are particularly suitable for use as the first organic compound.

[0123] Furthermore, when the threshold for electron density distribution in the atomic unit system is 0.0004e / a0 3 At that time, the minimum ESP value of the organic compound represented by structural formula (103) was -0.090E. h The following applies when the threshold for electron density distribution in the atomic unit system is 0.003e / a0. 3 The minimum value of ESP is -0.13E. h The following is further suitable for use as a first organic compound.

[0124] Furthermore, when the first organic compound has a high basicity, its interaction with holes can significantly reduce the hole transport properties of the electron injection layer, thereby enabling a light-emitting device with high efficiency and low driving voltage, 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.

[0125] 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.

[0126] Alternatively, the acidity coefficient can be calculated. For example, the acidity coefficient pKa can be calculated using the following method.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] The acidity coefficient pKa of 2,9hpp2Phen is 13.35, that of 4,7hpp2Phen is 13.42, that of Pyrrd-Phen is 11.23, that of mPPhen2P is 5.16, that of NBphen is 5.59, and that of Bphen is 5.62.

[0131] <Estimating HOMO levels in the interaction between metal oxides and organic compounds using quantum chemical calculations> Next, quantum chemical calculations were used to estimate the stability energy of the interaction between the metal oxide and the first organic compound containing a phenanthroline ring with electron donation capability, as well as the HOMO energy level formed at this time.

[0132] 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 structures in the ground state for the first organic compound, the second organic compound, and the metal oxide, as well as the most stable structures in the ground state for the composites of the first organic compound and the metal oxide, the composites of the second organic compound and the metal oxide, and the composites of the first organic compound, the second organic compound, and the metal oxide. 6-311G(d,p) and LanL2DZ were used as basis functions, and B3LYP was used as the functional. Next, the stability energy was calculated by subtracting the sum of the total energies of the organic compound monomers and the metal oxide from the total energy of the composite of the organic compound and the metal oxide. That is, (stability energy) = (total energy of the composite of the organic compound and the metal oxide) - (total energy of the organic compound monomers) - (total energy of the metal oxide).

[0133] The following table shows the results calculated using 4,7-di-1-pyrrolidinyl-1,10-phenanthroline (abbreviated: Pyrrd-Phen) as the first organic compound, 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated: mPPhen2P) or 2,9-di(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated: NBPhen) as the second organic compound, and silver oxide (Ag₂O) or indium oxide (In₂O₃) as the metal oxide. Note that the HOMO energy levels in the table are calculated values ​​and may differ from actual measured values.

[0134] [Table 3] As shown in the table above, the composite material of silver oxide (Ag₂O) and the first organic compound (Pyrrd-Phen) has a negative stability energy. When this organic compound is mixed with a metal oxide, the mixture is more energy-stable when interaction occurs, compared to the case where the organic compound and the metal oxide do not interact. In this case, the HOMO energy level formed by this composite material is higher than that of the first organic compound (Pyrrd-Phen), exhibiting better electron injection properties, and is therefore preferred.

[0135] Furthermore, compared to the composite material of silver oxide (Ag₂O) and the first organic compound (Pyrrd-Phen), the composite material of silver oxide (Ag₂O), the first organic compound (Pyrrd-Phen), and the second organic compound (mPPhen₂P) exhibits greater energy stability and is therefore preferred. Additionally, the HOMO energy level formed in this process is higher than the individual HOMO energy levels of the first organic compound (Pyrrd-Phen) and the second organic compound (mPPhen₂P), and also higher than the HOMO energy level of the composite material of silver oxide (Ag₂O) and the first organic compound (Pyrrd-Phen). A higher HOMO energy level indicates better electron injection performance, and is therefore preferred.

[0136] Furthermore, as shown in the table above, indium oxide (In₂O₃) is preferably used as the metal oxide, as this results in a more energy-stable composite material of the metal oxide, the first organic compound, and the second organic compound. Additionally, the resulting HOMO energy level is higher than the individual HOMO energy levels of the first and second organic compounds. A higher HOMO energy level indicates better electron injection performance, making this method preferred.

[0137] Note that, considering the manufacturing process of light-emitting devices, the EL layer of light-emitting devices is generally deposited using vacuum evaporation in many cases. As for the materials used in this process, materials that can be easily vacuum-deposited, i.e., materials with low melting points, are preferred. Because metal oxides belonging to Group 11 and Group 13 elements have low melting points, they are suitable for vacuum evaporation. Furthermore, metal oxides belonging to Group 11 and Group 13 elements are stable to atmospheric oxygen and water, making them preferred. Additionally, by using vacuum evaporation, it is easier to mix metal oxides and organic compounds, which is also preferred.

[0138] <Second Organic Compound> In addition to the metal oxide and the first organic compound, the electron-injected layer preferably also contains a second organic compound. Including the second organic compound can improve heat resistance and electron transport properties, among other things.

[0139] 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. Furthermore, any substance other than those mentioned above can be used as long as its electron transport capacity is higher than its hole transport capacity.

[0140] As materials with electron transport properties, preferred materials include metal complexes such as bis(10-hydroxybenzo[h]quinoline)beryllium(II) (abbreviated: BeBq2), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated: BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviated: Znq), bis[2-(2-benzoxazolyl)phenol]zinc(II) (abbreviated: ZnPBO), and bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviated: ZnBTZ), as well as organic compounds including π-electron-deficient heteroaromatic rings. Examples of organic compounds with π-electron-deficient heteroaromatic ring skeletons include organic compounds containing heteroaromatic rings with polyazole skeletons, organic compounds containing heteroaromatic rings with pyridine skeletons, organic compounds containing heteroaromatic rings with diazine skeletons, and organic compounds containing heteroaromatic rings with triazine skeletons.

[0141] Organic compounds containing heteroaromatic rings with a diazine (pyrimidine, pyrazine, or pyridazine) skeleton, organic compounds containing heteroaromatic rings with a pyridine skeleton, or organic compounds containing heteroaromatic rings with a triazine skeleton are preferred due to their high reliability. In particular, organic compounds containing heteroaromatic rings with a diazine (pyrimidine or pyrazine) skeleton or organic compounds containing heteroaromatic rings with a triazine skeleton exhibit high electron transport properties, which helps to reduce the driving voltage. Furthermore, benzofuran-pyrimidine skeletons, benzothiophene-pyrimidine skeletons, benzofuran-pyrazine skeletons, and benzothiophene-pyrazine skeletons are preferred due to their high acceptor activity and reliability.

[0142] Examples of organic compounds with π-electron-deficient heteroaromatic ring skeletons include 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (CO11), 2,2',2''-(1,3,5-phenyltriyl)tris(1-phenyl-1H-benzimidazole) (TPBI), and 2-[3 Organic compounds with an azole skeleton, such as [-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs); 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), phenanthroline (abbreviation: Bphen), copper hydroxide (abbreviation: BCP), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9- Organic compounds containing heteroaromatic rings with a pyridine skeleton, such as phenyl-1,10-phenanthroline (mPPhen2P), 2-[3-(2-triphenylene)phenyl]-1,10-phenanthroline (mTpPPhen), 2-phenyl-9-(2-triphenylene)-1,10-phenanthroline (Ph-TpPhen), 2-[4-(9-phenanthyl)-1-naphthyl]-1,10-phenanthroline (PnNPhen), and 2-[4-(2-triphenylene)phenyl]-1,10-phenanthroline (pTpPPhen); and 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (2mDBTPDBq-I). I), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq-III), 2-[3' ...h] Quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 2-{3-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviation: 2mPCCzPDBq), 9-[3'-(dibenzothiophene-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 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) (abbreviation: 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-(dibenzothiophen-4-yl)phenyl]benzofuran[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuran[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-4-yl)(biphenyl-3-yl)]naphtho[1',2':4,5]furan[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-binaphtho)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuran[3,2-d]pyrimidine Pyridine (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-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthyl-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-Bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: 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: mBnfBP) Tzn), 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: PCCzPTzn), 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 Phenyl-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-yl)phenyl]phenyl}-4,6-diphenyl-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-pyridyl)-5-(9-phenanthyl)phenyl]-4,6-diphenyl-1,3,5-triazine 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: BP-Icz(II)Tzn), 2-[3'-(triphenyl-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzothiophene]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',Organic compounds containing heteroaromatic rings with a triazine skeleton, such as 1''-terphenyl]-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviated as: mBP-TPDBfTzn) and 2-[4-(2-naphthyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9'-[9H]oxanthracene]-4-yl-1,3,5-triazine (abbreviated as: βNP-SFx(4)Tzn), are preferred. Furthermore, organic compounds containing heteroaromatic rings with a diazine skeleton, organic compounds containing heteroaromatic rings with a pyridine skeleton, or organic compounds containing heteroaromatic rings with a triazine skeleton are preferred due to their high reliability. In particular, organic compounds containing heteroaromatic rings with a diazine (pyrimidine or pyrazine) skeleton or organic compounds containing heteroaromatic rings with a triazine skeleton have high electron transport properties, which helps to reduce the driving voltage.

[0143] Among the above materials, organic compounds containing phenanthrene rings such as Bphen, BCP, NBphen and mPPhen2P are preferred, and organic compounds with phenanthrene ring dimer structures such as mPPhen2P are even more preferred because they have high heat resistance and high stability.

[0144] Furthermore, the second organic compound preferably has 25 or more and 100 or less carbon atoms. By using this number of carbon atoms, an organic compound with good sublimation properties can be achieved, thereby suppressing the thermal decomposition of the organic compound during vacuum evaporation and thus obtaining good material utilization efficiency.

[0145] Furthermore, the second organic compound is preferably an organic compound with a glass transition temperature (Tg) of 100°C or higher. This allows the electron-injected layer to have high heat resistance and is less prone to crystallization. Thus, even when a portion of the organic compound layer is processed using photolithography, crystallization is less likely.

[0146] Examples of organic compounds containing a phenanthroline ring and having a glass transition point (Tg) above 100℃ include NBphen (Tg: 165℃), mPPhen2P (Tg: 135℃), 2,2'-(biphenyl-4,4'-diyl)bis(9-phenyl-1,10-phenanthroline) (abbreviated as PPhen2BP) (Tg: 166℃), 2,2'-biphenyl-3,3'-diylbis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2BP) (Tg: 144℃), 2,8-bis(phenanthroline-5-yl)dibenzofuran (abbreviated as 2,8Phen2DBf) (Tg: 210℃), and 5,5',5''-(phenyl-1,3,5-triyl)tri-1,10-phenanthroline (abbreviated as Phen3P) (Tg: 257℃).

[0147] Furthermore, as the second organic compound, an organic compound with an acidity coefficient pKa of 4 or higher and less than 8 can be used. This improves the resistance to water and chemicals used in the photolithography process.

[0148] 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 oxide 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.

[0149] 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. Furthermore, 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.

[0150] Therefore, electrons can be readily supplied from the donor level formed by the first organic compound and the metal oxide to the second organic compound. Furthermore, this facilitates electron transport within the second organic compound.

[0151] 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.

[0152] Furthermore, in addition to the metal oxide and the first organic compound, the electron-injected layer preferably also contains a second organic compound, thereby enabling efficient interactions between the materials. This can be confirmed by measuring the spin density using the spin resonance method (ESR).

[0153] For example, the spin density of a film containing a metal oxide and a first organic compound, as measured by ESR, is preferably higher than that of a film containing a metal oxide and a second organic compound, as measured by ESR. Furthermore, the spin density of a film containing a metal oxide, a first organic compound, and a second organic compound, as measured by ESR, is preferably higher than that of a film containing any two of the following materials: a metal oxide, a first organic compound, and a second organic compound. In this case, efficient interaction between the materials can be confirmed.

[0154] More specifically, in the film comprising the metal oxide and the first organic compound, for example, preferably, the spin density of the signal observed using electron spin resonance at a g value of around 2.00 is 5 × 10⁻⁶. 16 spins / cm 3 The above is preferred to be 1×10 17 spins / cm 3 The above. In this case, it can be confirmed that efficient interactions occur between materials in the layer having the combination of metal oxide and the first organic compound. Alternatively, in a film containing metal oxide, the first organic compound, and the second organic compound, for example, preferably, the spin density arising from a signal observed using electron spin resonance at a g value of around 2.00 is 5 × 10⁻⁶. 16 spins / cm 3 The above is preferred to be 1×10 17 spins / cm 3 That's all. In this case, it can be confirmed that the layer containing a combination of metal oxide, a first organic compound, and a second organic compound exhibits more efficient material-to-material interaction than a layer containing only two of the aforementioned materials. In this case, in the mixed film containing the metal oxide and the second organic compound, for example, the spin density arising from the signal observed near a g value of 2.00 using electron spin resonance is 2 × 10⁻⁶. 16 spins / cm 3 Hereinafter, in a mixed film containing a first organic compound and a second organic compound, for example, the spin density of the signal observed using electron spin resonance at a g value of around 2.00 is 2 × 10⁻⁶. 16 spins / cm 3 the following.

[0155] In the electron injection layer, the molar ratio of the metal oxide to the first organic compound (or the sum of the first organic compound and the second organic compound) is preferably 0.1 or more and 10 or less, 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 including an electron injection layer comprising a metal oxide and a first organic compound (or a first organic compound and a second organic compound) in the above ratio, an electron injection layer with good electron injection performance can be provided. Alternatively, the second organic compound may not be used, but when the second organic compound is used, the volume ratio of the first organic compound to the second organic compound is preferably 0.1 or more and 10 or less, 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 performance can be provided. In addition, by using an organic compound with good thermal properties and high Tg as the second organic compound, a highly reliable organic EL device can be provided.

[0156] Furthermore, the thickness of the electron injection layer is preferably 2 nm or more and 20 nm, more preferably 5 nm or more and 10 nm or less. When the electron injection layer adopts a stacked structure of a metal oxide layer and a layer containing a first organic compound, the metal oxide layer is preferably 0.1 nm or more and 5 nm or less, more preferably 0.2 nm or more and 2 nm or less. Furthermore, when the electron injection layer adopts a stacked structure of a metal oxide layer and a layer containing a first organic compound, the thickness of the layer containing the first organic compound is preferably 2 nm or more and 20 nm, more preferably 5 nm or more and 10 nm or less.

[0157] The light-emitting device of one aspect of the present invention having the above structure can have good characteristics even if it is exposed to the atmosphere before forming the second electrode or is processed using photolithography accompanied by exposure to the atmosphere.

[0158] Furthermore, a light-emitting device of one embodiment of the present invention having the above-described structure can be a highly reliable light-emitting device with high current efficiency and suppression of driving voltage rise.

[0159] In addition, although the light-emitting device of one aspect of the present invention is particularly preferred as a light-emitting device manufactured by a photolithography process, light-emitting devices manufactured without a photolithography process also have high atmospheric stability, thus improving yield and reducing costs as atmosphere management in the manufacturing process does not need to be too strict.

[0160] (Implementation Method 2) In this embodiment, a light-emitting device according to one aspect of the present invention is described in detail.

[0161] Figure 1 is a schematic diagram of a light-emitting device according to one embodiment of the present invention. In the light-emitting device, a first electrode 101 is disposed on an insulator 100, and an EL layer 103 is included between the first electrode 101 and a second electrode 102. The EL layer 103 includes at least a light-emitting layer 113 and an electron injection layer 115. The light-emitting layer 113 is a layer containing a light-emitting material, which emits light when a voltage is applied between the first electrode 101 and the second electrode 102.

[0162] like Figure 1A As shown, the EL layer 103 preferably includes functional layers such as a hole injection layer 111, a hole transport layer 112, an electron transport layer 114, and an electron injection layer 115, in addition to the light-emitting layer 113. Furthermore, the EL layer 103 may also include functional layers other than those mentioned above, such as a hole blocking layer, an electron blocking layer, an exciton blocking layer, and a charge generation layer. Conversely, any of the above layers may not be provided.

[0163] Additionally, the electron-injected layer 115 is a layer comprising a metal oxide and an organic compound (first organic compound) containing a phenanthroline ring having an electron-donating group, as described in Embodiment 1. The electron-injected layer 115 may also comprise other organic compounds (second organic compounds).

[0164] The specific structure of the electron injection layer 115 has been described in detail in Embodiment 1, so repeated descriptions are omitted here.

[0165] Note that although this embodiment shows an example where the first electrode 101 is an electrode containing an anode, the second electrode 102 is an electrode containing a cathode, and the first electrode 101 is formed on one side of the insulator 100, a structure in which the second electrode 102 is formed on one side of the insulator 100 can also be used, i.e., a so-called reverse stacked structure. In this case, the light-emitting device has a stacked structure in which the second electrode 102, the electron injection layer 115, (electron transport layer 114), the light-emitting layer 113, (hole transport layer 112, hole injection layer 111), and the first electrode 101 are stacked sequentially from the insulator 100 side. When this reverse stacked structure is used in the light-emitting device, the relatively stable hole injection layer 111 becomes the surface, thereby enabling a light-emitting device with higher reliability.

[0166] Furthermore, the first electrode 101 and the second electrode 102 are formed as a single-layer structure or a multilayer structure. When the multilayer structure is present, the layer in contact with the EL layer 103 is used as an anode or a cathode. When the electrodes have a multilayer structure, there are no restrictions on the work function of the layers other than the layer in contact with the EL layer 103, and materials can be selected according to the required characteristics such as resistance, ease of processing, reflectivity, light transmittance, and stability.

[0167] The anode is preferably formed using metals, alloys, conductive compounds, and mixtures thereof with a high work function (specifically 4.0 eV or higher). Examples include indium tin oxide (ITO), indium tin oxide (ITSO) 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. Examples of formation methods include sputtering indium tin oxide using a target containing 1 wt% to 20 wt% zinc oxide. Furthermore, indium tin 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. Furthermore, materials used for 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), titanium (Ti), aluminum (Al), or nitrides of metallic materials (e.g., titanium nitride). Additionally, layers stacked with these materials can also be used as the anode. For example, a film sequentially stacked with Al, Ti, and ITSO on Ti is preferred due to its good reflectivity, resulting in high efficiency and achieving high resolution of several thousand ppi. Furthermore, graphene can also be used as the anode material. Moreover, by using a composite material that can constitute the hole injection layer 111 described later as the layer in contact with the anode (typically a hole injection layer), the work function can be disregarded when selecting the electrode material.

[0168] Hole injection layer 111 is in contact with the anode and facilitates hole injection into EL layer 103. The hole injection layer 111 can be formed using phthalocyanine compounds or complexes such as phthalocyanine (H2Pc) and copper phthalocyanine (CuPc); aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (DPAB) and 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (DNTPD); or polymers such as poly(3,4-ethylenedioxythiophene) / (polystyrene sulfonic acid) (PEDOT / PSS).

[0169] Furthermore, the hole injection layer 111 can also be composed of a substance with electron-accepting properties. As such, organic compounds with electron-withdrawing groups (halogen groups, cyano groups, etc.) can be used, including 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinone dimethylethane (abbreviated: F4-TCNQ), chloroquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviated: F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-yl)malononitrile, etc. In particular, compounds such as HAT-CN, which have electron-withdrawing groups bonded to fused aromatic rings with multiple heteroatoms, are thermally stable and therefore preferred. Furthermore, [3] axylene derivatives having electron-withdrawing groups (especially halogen groups such as fluorine groups, cyano groups, etc.) are particularly preferred due to their 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 also be used as acceptor substances.

[0170] Furthermore, the hole injection layer 111 is preferably formed using a composite material containing the aforementioned acceptor material and an organic compound with hole transport properties.

[0171] Various organic compounds with hole-transporting properties can be used as the organic compound for use in composite materials, such as aromatic amines, heteroaromatics, 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 ratio of / Vs or higher. The organic compounds with hole-transporting capabilities used in composite materials are preferably compounds containing 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 containing 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 aromatic or heteroaromatic rings.

[0172] Such hole-transporting organic compounds preferably have 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.

[0173] 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'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl- 1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-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.

[0174] In addition, as a material with hole transport capabilities, other aromatic amine compounds such as N,N'-bis(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (DTDPPA), 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), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (DPA3B) can also be used.

[0175] By forming a hole injection layer 111, hole injection capability can be improved, thereby obtaining a light-emitting device with low driving voltage.

[0176] Furthermore, organic compounds with receptor properties can be easily formed in substances with receptor properties using vapor deposition, making them easy-to-use materials.

[0177] The hole transport layer 112 is formed by comprising an organic compound with hole transport properties. Preferably, the organic compound with hole transport properties has a content of 1 × 10⁻⁶. -6 cm 2 Hole mobility above / Vs.

[0178] 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 high reliability, excellent hole transport properties, and ability to reduce driving voltage. Note that materials with hole transport properties, such as those used in the hole injection layer 111, can also be appropriately used as materials constituting the hole transport layer 112.

[0179] The light-emitting layer 113 is a layer containing a light-emitting material, preferably containing both the light-emitting material and a host material. Note that the light-emitting layer may also contain other materials. Furthermore, it may be a two-layer stack with different compositions.

[0180] 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.

[0181] 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.

[0182] 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-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as 1,6mMemFLPAPrn). [-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthrayl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthrayl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), dinaphthalene, 2,5,8,11-tetra-tert-butyl dinaphthalene (abbreviation: TBP), 4-(10-phenyl-9-anthrayl)-4'-(9-phenyl-9H- Carbazole-3-yl)triphenylamine (abbreviated as PCPAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis(,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](chrys) N-(9,10-diphenyl-2-anthrayl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviated as: DBC1), coumarin 30, N-(9,10-diphenyl-2-anthrayl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviated as: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthrayl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviated as: 2PCABPhA), N-(9,10-diphenyl-2-anthrayl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviated as: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthrayl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviated as: 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-diphenyltetraphenyl (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)-[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, possess high hole-trapping ability, high luminescence efficiency, and high reliability, making them a preferred choice.

[0183] In addition, 5,9-diphenyl-5,9-diaza-13b-boronazonaphtho[3,2,1-de]anthracene (abbreviated as DABNA1), 9-(biphenyl-3-yl)-N,N,5,11-tetraphenyl-5H,9H-[1,4]benzozaborane[2,3,4-kl]phenazborine-3-amine (abbreviated as DABNA2), and 2,12-bis(tert-butyl)-5,9-bis(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzozaborane[2,3,4-kl]phenazborine-7-amine (Abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzozaboron[2,3,4-kl]phenazaboron-7-amine (Abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzozaboron[2,3,4-kl]phenazaboron (Abbreviation: Me-tBu4DABNA), N 7 N 7 N 13 N 13 Nitrogen- and boron-containing fused heteroaromatic compounds, especially those with a diaza-boronanthroline skeleton, exhibit narrow emission spectra and can produce blue luminescence with good color purity, and therefore can be appropriately used.

[0184] In addition to the above, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazole-9-yl]-2,5,15,18-tetra(1,1-dimethylethyl)indole[3,2,1-de]indole[3',2',1':8,1][1,4]benzozaboron[2,3,4-kl]phenazaboron (abbreviated as: BBCz-G), 9,11-bis[3,6-bis(1,1-dimethylethyl)-9H-carbazole-9-yl]-2,5,15,18-tetra(1,1-dimethylethyl)indole[3,2,1-de]indole[3',2',1':8,1][1,4]benzozaboron[2,3,4-kl]phenazaboron (abbreviated as: BBCz-Y), etc. can also be used appropriately.

[0185] When phosphorescent materials are used as luminescent materials in the luminescent layer, the following substances can be cited as examples of usable materials.

[0186] 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]) and tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Mptz)3]). Complexes; organometallic iridium complexes with a 1H-triazole skeleton, such as tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazole]iridium(III) (abbreviated as [Ir(Mptz1-mp)3]) and tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium(III) (abbreviated as [Ir(Prptz1-Me)3]); fac-tris[1-(2,6-di] [Ir(iPrpim)3]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]), [tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazo- Organometallic iridium complexes with an imidazole skeleton, such as 2-yl-κN3}-4-cyanophenyl-κC (abbreviated as CNImIr); organometallic complexes with a benzimidazole skeleton, such as tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC2)phenyl-κC]iridium(III) (abbreviated as [Ir(cb)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) pyridine carboxylate (abbreviated as 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. These substances are compounds that emit blue phosphorescence and have emission peaks in the wavelength region of 450 nm to 520 nm.

[0187] In addition, 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 [Ir(mpmppm)2(acac)]((acetylacetonate)bis(4,6-diphenylpyrimidine)iridium(III)]([Ir(dppm)2(acac)]); organometallic iridium complexes with a pyrazine skeleton, such as [Ir(mppr-Me)2(acac)]((acetylacetonate)bis(5-isopropyl-3-methyl-2-phenylpyrazine)iridium(III)]([Ir(mppr-iPr)2(acac)]); and 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-pyridyl-κN2)phenyl-κC]iridium (III) (abbreviation: [Ir(5mppy-d3)2(mbfpypy-d3)]), [2-d3-methyl-(2-pyridyl-κN)benzofurano[2,3-b]pyridin-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium (III) (abbreviation: [Ir(ppy)2(mbfpypy-d3)]), [2-(4-d3-methyl-5-phenyl-2-pyridyl-κN2)phenyl-κC]bis[2-(5-d3-methyl-2- Organometallic iridium complexes with a pyridine skeleton, such as [Ir(5mppy-d3)2(mdppy-d3)]iridium(III)[2-methyl-(2-pyridyl-κN)benzofurano[2,3-b]pyridyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(III)[Ir(ppy)2(mbfpypy)], and [2-(4-methyl-5-phenyl-2-pyridyl-κN)phenyl-κC]bis[2-(2-pyridyl-κN)phenyl-κC]iridium(Ir(ppy)2(mdppy)]; and rare earth metal complexes such as tri(acetylacetonyl)(monophenanthroline)terbium(III)[Tb(acac)3(Phen)]). The aforementioned substances are primarily compounds that exhibit green phosphorescence and possess emission peaks in the 500 nm to 600 nm wavelength region. Furthermore, organometallic iridium complexes with a pyrimidine framework are particularly preferred due to their exceptionally superior reliability or luminescent efficiency.

[0188] In addition, examples of organogolds with pyrimidine skeletons include: (diisobutyrylmethane)bis[4,6-bis(3-methylphenyl)pyrimidinyl]iridium(III) (abbreviated as: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinyl](dineopentaylmethane)iridium(III) (abbreviated as: [Ir(5mdppm)2(dpm)]), and bis[4,6-bis(naphth-1-yl)pyrimidinyl](dineopentaylmethane)iridium(III) (abbreviated as: [Ir(d1npm)2(dpm)]). Organometallic iridium complexes with a pyrazine skeleton, such as (acetylacetonate)bis(2,3,5-triphenylpyrazine)iridium(III) (abbreviated as [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazine)(dinepentanoylmethane)iridium(III) (abbreviated as [Ir(tppr)2(dpm)]), and (acetylacetonate)bis[2,3-bis(4-fluorophenyl)quinoxaloline]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 include iridium(III) acetylacetone (abbreviated as: [Ir(piq)2(acac)]), (3,7-diethyl-4,6-nonanedione-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinolinyl-κN]phenyl-κC]iridium(III), (3,7-diethyl-4,6-nonanedione-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolinyl-κN]phenyl-κC]iridium(III). The compounds include 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) (monopraninol) europium(III) (abbreviated as [Eu(DBM)3(Phen)]) and tris[1-(2-thiophenecarboxyl)-3,3,3-trifluoroacetone] (monopraninol) europium(III) (abbreviated as [Eu(TTA)3(Phen)]). These substances are red phosphorescent compounds with emission peaks in the 600 nm to 700 nm wavelength region. Furthermore, organometallic iridium complexes with a pyrazine framework exhibit good red chromaticity.

[0189] In addition to the phosphorescent compounds mentioned above, other known phosphorescent compounds may also be used.

[0190] 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).

[0191] [Chemical Formula 5] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindol[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, Heterocyclic compounds such as 3,5-triazine (PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-oxanthracene-9-one (ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridin)phenyl]sulfone (DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridin-9,9'-anthracene]-10'-one (ACRSA) possessing one or both π-electron-rich and π-electron-deficient heterocyclic rings are preferred. These heterocyclic compounds exhibit high electron and hole transport properties due to the presence of both π-electron-rich and π-electron-deficient heterocyclic rings. Among the skeletons with 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 are highly acceptor and reliable, and are therefore preferred. Furthermore, among the skeletons with π-electron-rich heteroaromatic rings, acridine, phenoxazine, phenothiazine, furan, thiophene, and pyrrole skeletons are stable and reliable, and are therefore preferred to have at least one of these skeletons. Moreover, dibenzofuran skeletons are preferred as furan skeletons, and dibenzothiophene skeletons are preferred as thiophene skeletons. As pyrrole skeletons, indole, carbazole, indolecarbazole, 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 ring exhibits high electron-donating and electron-accepting properties, while the energy difference between the S1 and T1 energy levels decreases, 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, phenazine skeletons, etc., can be used as π-electron-rich skeletons.Furthermore, as π-electron-deficient skeletons, the following can be used: oxanthracene skeleton, thioxanthene dioxide skeleton, oxadiazole skeleton, triazole skeleton, imidazole skeleton, anthraquinone skeleton, boron-containing skeletons such as phenylborane or boranthrene, aromatic or heteroaromatic rings with nitrile or cyanobenzene, carbonyl skeletons such as benzophenone, phosphine oxide skeleton, sulfone skeleton, etc. 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.

[0192] [Chemical Formula 6] TADF materials refer to materials with a small energy difference between the S1 and T1 levels and the ability to convert triple excitation energy into single excitation energy through antisystem crossing. Therefore, they can upconvert triple excitation energy into single excitation energy (antisystem crossing) with minimal thermal energy, efficiently generating singlet excited states. Furthermore, triple excitation energy can be converted into luminescence.

[0193] 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.

[0194] 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. Regarding TADF materials, when the wavelength energy of the extrapolated line obtained by drawing a tangent 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 drawing a tangent at the tail of the short-wavelength side of the phosphorescence spectrum is taken as the T1 energy level, the difference between S1 and T1 is preferably 0.3 eV or less, more preferably 0.2 eV or less.

[0195] 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.

[0196] 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.

[0197] As a material with hole transport capabilities, organic compounds having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton are preferred. As a π-electron-rich heteroaromatic ring, a fused aromatic ring comprising at least one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton is preferred, specifically a carbazole ring, a dibenzothiophene ring, or a ring in which these rings are also fused with an aromatic ring or a heteroaromatic ring.

[0198] Such hole-transporting organic compounds preferably have 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.

[0199] Examples of such organic compounds 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), 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: 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), N-phenyl Compounds with an aromatic amine skeleton, such as -N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobis[9H-fluorene]-2-amine (abbreviated as: PCBASF); compounds with a carbazole skeleton, such as 1,3-bis(N-carbazolyl)benzene (abbreviated as: mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviated as: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as: CzTP), and 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole (abbreviated as: PCCP); and compounds with a carbazole skeleton, such as 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviated as: DB). Compounds with a thiophene skeleton, such as T3P-II, 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviated as DBTFLP-III), and 4-[4-(9-phenyl-9H-fluoren-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-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among these, compounds with an aromatic amine skeleton and compounds with a carbazole skeleton are preferred due to their good reliability, high hole transport properties, and ability to reduce the driving voltage. Furthermore, organic compounds with hole transport properties, exemplified as hole transport layers, can also be used.

[0200] As materials with electron transport properties, preferred materials include metal complexes such as bis(10-hydroxybenzo[h]quinoline)beryllium(II) (abbreviated: BeBq2), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated: BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviated: Znq), bis[2-(2-benzoxazolyl)phenol]zinc(II) (abbreviated: ZnPBO), and bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviated: ZnBTZ), as well as organic compounds including π-electron-deficient heteroaromatic rings. Examples of organic compounds containing π-electron-deficient heteroaromatic ring skeletons include organic compounds containing heteroaromatic rings with azole skeletons, organic compounds containing heteroaromatic rings with pyridine skeletons, organic compounds containing heteroaromatic rings with diazine skeletons, and organic compounds containing heteroaromatic rings with triazine skeletons.

[0201] Organic compounds containing heteroaromatic rings with a diazine (pyrimidine, pyrazine, or pyridazine) skeleton, organic compounds containing heteroaromatic rings with a pyridine skeleton, or organic compounds containing heteroaromatic rings with a triazine skeleton are preferred due to their good reliability. In particular, organic compounds containing heteroaromatic rings with a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing heteroaromatic rings with a triazine skeleton exhibit high electron transport properties, which helps to reduce the driving voltage. Furthermore, benzofuran-pyrimidine skeletons, benzothiophene-pyrimidine skeletons, benzofuran-pyrazine skeletons, and benzothiophene-pyrazine skeletons are preferred due to their high acceptor activity and reliability.

[0202] Examples of organic compounds with π-electron-deficient heteroaromatic ring skeletons include: 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated: PBD), 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated: CO11), 2,2',2''-(1,3,5-phenyltriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated: TPBI), 2-[3 Organic compounds with an azole skeleton, such as [-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs); 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), phenanthroline (abbreviation: Bphen), copper hydroxide (abbreviation: BCP), 2,9-bis(naphthyl-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 2,2'-(1,3-phenylene)bis(9-phenylene) Organic compounds containing heteroaromatic rings with a pyridine skeleton, such as 2-[3-(2-triphenylene)phenyl]-1,10-phenanthroline (mPPhen2P), 2-[3-(2-triphenylene)phenyl]-1,10-phenanthroline (mTpPPhen), 2-phenyl-9-(2-triphenylene)-1,10-phenanthroline (Ph-TpPhen), 2-[4-(9-phenanthyl)-1-naphthyl]-1,10-phenanthroline (PnNPhen), and 2-[4-(2-triphenylene)phenyl]-1,10-phenanthroline (pTpPPhen); and 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (2mDBTPDBq-II). 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazole-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-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq-III), 2-[4'-(9-phenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 2-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq-III), 2-[4'-(9-phenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2h] Quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(dibenzothiophene-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: 4,6m PnP2Pm), 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) (abbreviation: 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-(dibenzothiophen-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(dibenzothiophen-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-(dibenzothiophen-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDB tPBfpm), 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-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthyl-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-Bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: 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: mBnfBPT) zn), 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: PCCzPTzn), 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 2-[3-(4,6-diphenyl-1,3,5-triazine)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (mINc(II)PTzn), 2-{3-[3-(dibenzothiophene-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (mDBtBPTzn), 2,4,6-tris[3'-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthyl)phenyl]-4,6-diphenyl-1,3,5-triazine - Triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenyl-indolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3'-(triphenyl-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',Organic compounds containing a heteroaromatic ring with a triazine skeleton, such as [1''-terphenyl]-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviated as: mBP-TPDBfTzn). Furthermore, organic compounds containing a heteroaromatic ring with a diazine skeleton, a heteroaromatic ring with a pyridine skeleton, or a heteroaromatic ring with a triazine skeleton are preferred due to their high reliability. In particular, organic compounds containing a heteroaromatic ring with a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring with a triazine skeleton exhibit high electron transport properties, which helps to reduce the driving voltage.

[0203] As a TADF material that can be used as the host material, the same materials mentioned above as TADF materials can 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 acts as an energy donor, and the luminescent material acts as an energy acceptor.

[0204] 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.

[0205] 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.

[0206] To efficiently generate a singlet excitation energy from a triplet excitation energy via antisystem crossing, it is preferable to induce 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 containing 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.

[0207] 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 both high luminous efficiency and durability can be achieved. Among the anthracene framework materials used as host materials, those with a diphenylanthracene framework, especially a 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. When the host material has a benzo[a]carbazole framework with a benzene ring fused to a carbazole, its HOMO level is about 0.1 eV shallower than that of the carbazole framework, making hole injection easier, which is even 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 the carbazole framework, which not only facilitates hole injection but also improves hole transport and heat resistance, making it preferred. Therefore, a further preferred material for use as the host material is one having a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzo[a]carbazole skeleton or a dibenzo[a]carbazole skeleton). 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] The following are a list of herbal preparations: 1-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,βADN), 2-(10-phenylanthracene-9-yl)dibenzofuran, 2-(10-phenyl-9-anthyl)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-anthracene]phenyl}-2-ethyl-1H-benzimidazole (abbreviated as EtBImPBPhA), etc. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties and are therefore preferred.

[0208] Furthermore, the host material can also 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 composite region more easily. The weight ratio of the materials with hole transport properties to those with electron transport properties can be from 1:19 to 19:1.

[0209] 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.

[0210] Furthermore, these mixed materials can also be used to form excimer complexes. By selecting a combination of excimer complexes that emit 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 allows for a reduction in the driving voltage, making it also preferred.

[0211] Note that at least one of the materials forming the excitocomplex can be a phosphorescent material. This allows for the efficient conversion of triple excitation energy into single excitation energy via antisystem crosstalk.

[0212] Regarding the combination of materials for efficiently forming excitocomplexes, the HOMO energy level of the material with hole transport is preferably above the HOMO energy level of the material with electron transport. Furthermore, the LUMO energy level of the material with hole transport is preferably above 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).

[0213] 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 at a longer wavelength) 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 be confirmed.

[0214] Electron transport layer 114 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 described above may be used, as long as its electron transport capability is higher than its hole transport capability. As the aforementioned organic compounds, organic compounds containing a π-electron-deficient heteroaromatic ring are 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.

[0215] As an organic compound with electron transport properties that can be used in the electron transport layer 114, the organic compound with electron transport properties in the light-emitting layer 113 and the organic compound exemplified as the second organic compound that can be used in the electron injection layer 115 in Embodiment 1 can also be used. Among them, organic compounds containing heteroaromatic rings with a diazine skeleton, organic compounds containing heteroaromatic rings with a pyridine skeleton, and organic compounds containing heteroaromatic rings with a triazine skeleton have good reliability and are therefore preferred. In particular, organic compounds containing heteroaromatic rings with a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing heteroaromatic rings with a triazine skeleton have high electron transport properties, which helps to reduce the driving voltage. In particular, organic compounds with a phenanthroline skeleton such as mTpPPhen, PnNPhen, and mPPhen2P are preferred, and organic compounds with a phenanthroline dimer structure such as mPPhen2P have excellent stability and are therefore more preferred.

[0216] Furthermore, the electron transport layer preferably comprises an organic compound with an acidity coefficient pKa of less than 4.

[0217] Note that the electron transport layer 114 may also have a stacked structure. Furthermore, when the electron transport layer 114 has a stacked structure, the layer in contact with the light-emitting layer 113 may also be used as a hole-blocking layer. When the electron transport layer in contact with the light-emitting layer is used as a hole-blocking layer, it is preferable to use a material whose HOMO level is 0.5 eV or deeper than the HOMO level of the material contained in the light-emitting layer.

[0218] An electron injection layer 115 is formed between the electron transport layer 114 and the second electrode 102. The structure of the electron injection layer 115 has been described in detail in Embodiment 1, so repeated descriptions are omitted.

[0219] The second electrode 102 is an electrode that includes a cathode. The second electrode 102 may also have a stacked structure, in which case the layer in contact with the EL layer 103 is used 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 belonging to Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), or strontium (Sr), alloys containing them (MgAg, AlLi), compounds (lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), etc.), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing them. However, by providing an electron injection layer 115 or a thin film of a material with a small work function between the second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, indium oxide-tin oxide containing silicon or silicon oxide, etc., can be used as cathodes regardless of the size of the work function.

[0220] When the second electrode 102 is made of a material that is transparent to visible light, a light-emitting device that emits light from the second electrode 102 side can be formed. When the first electrode 101 is made of a material that is transparent to visible light, a light-emitting device that emits light from the first electrode 101 side can be formed.

[0221] These conductive materials can be formed using dry methods such as vacuum evaporation and sputtering, as well as inkjet printing and spin coating. Alternatively, they can be formed using wet methods such as sol-gel or wet methods using pastes of metallic materials.

[0222] Furthermore, when using a top-emitting light-emitting device, the light extraction efficiency can be improved by depositing an organic compound onto the second electrode to form a capping layer. The capping layer can be a single-layer structure or a multilayer structure. When using a multilayer structure, the light extraction efficiency can be further improved by employing organic compounds with different refractive indices.

[0223] Furthermore, various methods, whether dry or wet, can be used to form the EL layer 103. For example, vacuum evaporation, gravure printing, offset printing, screen printing, inkjet printing, or spin coating can also be used.

[0224] In addition, the electrodes or layers described above can also be formed by using different deposition methods.

[0225] Next, refer to Figure 1B This describes a light-emitting device (also called a stacked device or tandem device) with a structure having multiple light-emitting units stacked together. This light-emitting device has multiple light-emitting units between the anode and cathode. Each light-emitting unit has a... Figure 1AThe structure is roughly the same as that of EL layer 103 shown. That is to say, it can be said that... Figure 1B The light-emitting device shown is a light-emitting device with multiple light-emitting units, while Figure 1A The light-emitting device shown is a light-emitting device with one light-emitting unit.

[0226] exist Figure 1B In this structure, a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between the first electrode 501 and the second electrode 502, and an intermediate layer 513 is disposed between the first light-emitting unit 511 and the second light-emitting unit 512. The first electrode 501 and the second electrode 502 respectively correspond to... Figure 1A The first electrode 101 and the second electrode 102 are used in the process, and can be applied to... Figure 1A The same material as described. Furthermore, the first light-emitting unit 511 and the second light-emitting unit 512 may have the same structure or different structures.

[0227] The intermediate layer 513 has the function of injecting electrons into one light-emitting unit and holes into another light-emitting unit when a voltage is applied to the first electrode 501 and the second electrode 502. That is, in Figure 1B In the case where a voltage is applied such that the potential of the anode is higher than that of the cathode, the intermediate layer 513 can simply be a layer that injects electrons into the first light-emitting unit 511 and holes into the second light-emitting unit 512.

[0228] The intermediate layer 513 includes a charge generation layer. Furthermore, the charge generation layer includes at least a P-type layer 117. The P-type layer 117 is preferably formed using the composite material described above that constitutes the hole injection layer 111. Alternatively, the P-type layer 117 can also be formed by laminating a film containing an acceptor material (described as a material constituting the composite material) and a film containing a hole transport material. By applying a potential to the P-type layer 117, electrons and holes are injected into the electron transport layer 114 and the cathode, respectively, causing the light-emitting device to operate.

[0229] In addition to the P-type layer 117, the intermediate layer 116 preferably includes one or both of the electronic relay layer 118 and the N-type layer 119.

[0230] The electron relay layer 118 contains at least a material with electron transport properties and is capable of preventing the interaction between the N-type layer 119 and the P-type layer 117, while facilitating electron transfer. Preferably, the LUMO energy level of the electron-transporting material contained in the electron relay layer 118 is set between the LUMO energy level of the acceptor material in the P-type layer 117 and the LUMO energy level of the material contained in the layer in the electron transport layer 114 that contacts the intermediate layer 116. Specifically, the LUMO energy level of the electron-transporting material in the electron relay layer 118 is -5.0 eV or higher, preferably -5.0 eV or higher and -3.0 eV or lower. Furthermore, phthalocyanine materials or metal complexes having metal-oxygen bonds and aromatic ligands are preferably used as the electron-transporting material in the electron relay layer 118.

[0231] The N-type layer 119 can use alkali metals, alkaline earth metals, rare earth metals, and compounds of these substances (alkali metal compounds (including oxides such as lithium oxide, halides, lithium carbonate, cesium carbonate, etc.), alkaline earth metal compounds (including oxides, halides, carbonates) or rare earth metal compounds (including oxides, halides, carbonates)) and other substances with high electron injection capacity.

[0232] Furthermore, when the N-type layer 119 contains both electron-transporting and donor materials, the donor materials can be alkali metals, alkaline earth metals, rare earth metals, and compounds of these materials (alkali metal compounds (including oxides such as lithium oxide, halides, lithium carbonate, cesium carbonate, etc.), alkaline earth metal compounds (including oxides, halides, carbonates) or rare earth metal compounds (including oxides, halides, carbonates)). Organic compounds such as tetrathianaphthacene (TTN), nickel-cadmium, and decamethylnickel-cadmium can also be used. Additionally, the electron-transporting material can be the same material used for the electron transport layer 114 as described above.

[0233] Alternatively, a layer can be formed at the same location as the N-type layer 119 instead of the N-type layer 119, comprising a metal oxide and an organic compound containing a phenanthroline ring having an electron-donating group, as described in Embodiment 1 as an electron injection layer. Using this structure, a tandem light-emitting device with good characteristics can also be manufactured.

[0234] When the anode side of the light-emitting unit is in contact with the intermediate layer 513, the charge generation layer of the intermediate layer 513 can also function as the hole injection layer of the light-emitting unit, so the light-emitting unit may not need to have a hole injection layer. When the cathode side of the light-emitting unit is in contact with the intermediate layer 513, the intermediate layer 513 can also function as the electron injection layer of the light-emitting unit, so the light-emitting unit may not need to have an electron injection layer.

[0235] Although Figure 1B The description includes a light-emitting device with two light-emitting units, but similarly, light-emitting devices with three or more light-emitting units stacked can be applied. As in the light-emitting device according to this embodiment, by separating and arranging multiple light-emitting units between a pair of electrodes using an intermediate layer 513, an element can be realized that achieves high brightness emission while maintaining low current density and has a long lifespan. Furthermore, a light-emitting device capable of low-voltage driving and low power consumption can be realized.

[0236] Furthermore, by making the emission colors of each light-emitting unit different, the desired color of emission can be obtained from the entire light-emitting device. For example, by obtaining red and green emission colors from the first light-emitting unit and blue emission color from the second light-emitting unit in a light-emitting device with two light-emitting units, a light-emitting device that emits white light throughout the entire device can be obtained.

[0237] Furthermore, the aforementioned EL layer 103, first light-emitting unit 511, second light-emitting unit 512, intermediate layer, and electrodes can be formed using methods such as vapor deposition (including vacuum vapor deposition), droplet jetting (also known as inkjet printing), coating, and gravure printing. Additionally, they may contain low-molecular-weight materials, medium-molecular-weight materials (including oligomers and dendritic polymers), or high-molecular-weight materials.

[0238] Figure 2A This is a diagram of two adjacent light-emitting devices (light-emitting device 130a, light-emitting device 130b) included in a display device according to one aspect of the present invention.

[0239] The light-emitting device 130a includes an EL layer 103a between a first electrode 101a on an insulating layer 175 and a second electrode 102 opposite to the first electrode 101a. Although the structure shown includes a hole injection layer 111a, a hole transport layer 112a, a light-emitting layer 113a, an electron transport layer 114a, and an electron injection layer 115a, the EL layer 103a may also have a stacked structure different from the above structure.

[0240] The light-emitting device 130b includes an EL layer 103b between a first electrode 101b on an insulating layer 175 and a second electrode 102 opposite to the first electrode 101b. Although the structure shown includes a hole injection layer 111b, a hole transport layer 112b, a light-emitting layer 113b, an electron transport layer 114b, and an electron injection layer 115b, the EL layer 103b may also have a stacked structure different from the above structure.

[0241] The structures of the electron transport layer 114a and electron injection layer 115a in the light-emitting device 130a and the structures of the electron transport layer 114b and electron injection layer 115b in the light-emitting device 130b are preferably the structures described in Embodiment 1.

[0242] The second electrode 102 is preferably a continuous layer shared by the light-emitting devices 130a and 130b. Furthermore, the EL layers 103a and 103b are processed by photolithography separately after the formation of the electron injection layer 115a and after the formation of the electron injection layer 115b, respectively, and are therefore independent of each other. In one embodiment of the present invention, even if the light-emitting device is processed by photolithography separately after the formation of the electron injection layer 115a and after the formation of the electron injection layer 115b, a light-emitting device with good characteristics can be obtained. Furthermore, as... Figure 30A As shown, electron injection layer 115a and electron injection layer 115b can also be continuous layers shared by light-emitting device 130c and light-emitting device 130d.

[0243] Furthermore, the ends (contours) of the EL layer 103a are processed by photolithography, so they are approximately consistent in the direction perpendicular to the substrate. Similarly, the ends (contours) of the EL layer 103b are processed by photolithography, so they are approximately consistent in the direction perpendicular to the substrate.

[0244] Furthermore, due to the use of photolithography for processing, a gap d exists between EL layer 103a and EL layer 103d. In addition, by using photolithography to process the EL layer, the distance (shortest distance) between the first electrode 101c and the first electrode 101d can be made smaller than the distance during mask evaporation, and can be made to be more than 0.5μm and less than 5μm.

[0245] Figure 2B This is a diagram of two adjacent tandem light-emitting elements (light-emitting device 130c and light-emitting device 130d) manufactured by photolithography.

[0246] The light-emitting device 130c includes an EL layer 103c between the first electrode 101c and the second electrode 102 on the insulating layer 175. The EL layer 103c has a structure in which the first light-emitting unit 501c and the second light-emitting unit 502c are stacked with an intermediate layer 116c in between. Note that although Figure 2 shows an example of two light-emitting units stacked, more than three light-emitting units can also be stacked. The first light-emitting unit 501c includes a hole injection layer 111c, a first hole transport layer 112c_1, a first light-emitting layer 113c_1, and a first electron transport layer 114c_1. The intermediate layer 116c includes a P-type layer 117c, an electron relay layer 118c, and an N-type layer 119c. The presence or absence of the electron relay layer 118c is irrelevant. The second light-emitting unit 502c includes a second hole transport layer 112c_2, a second light-emitting layer 113c_2, a second electron transport layer 114c_2, and an electron injection layer 115c.

[0247] The light-emitting device 130d includes an EL layer 103d between the first electrode 101d and the second electrode 102 on the insulating layer 175. The EL layer 103d has a structure in which the first light-emitting unit 501d and the second light-emitting unit 502d are stacked with an intermediate layer 116d in between. Note that although Figure 2 shows an example of two light-emitting units stacked, three or more light-emitting units can also be stacked. The first light-emitting unit 501d includes a hole injection layer 111d, a first hole transport layer 112d_1, a first light-emitting layer 113d_1, and a first electron transport layer 114d_1. The intermediate layer 116d includes a P-type layer 117d, an electron relay layer 118d, and an N-type layer 119d. The presence or absence of the electron relay layer 118d is irrelevant. The second light-emitting unit 502d includes a second hole transport layer 112d_2, a second light-emitting layer 113d_2, a second electron transport layer 114d_2, and an electron injection layer 115d.

[0248] In light-emitting devices 130c and 130d, electron injection layers 115c and 115d preferably have the structure described in Embodiment 1.

[0249] The second electrode 102 is preferably a continuous layer shared by the light-emitting devices 130c and 130d. Furthermore, the EL layers 103c and 103d are processed by photolithography separately after the formation of the electron injection layer 115c and after the formation of the electron injection layer 115d, respectively, and are therefore independent of each other. In one embodiment of the present invention, even if the light-emitting device is processed by photolithography separately after the formation of the electron injection layer 115c and after the formation of the electron injection layer 115d, a light-emitting device with good characteristics can be obtained. Furthermore, as... Figure 30B As shown, electron injection layer 115c and electron injection layer 115d can also be continuous layers shared by light-emitting device 130c and light-emitting device 130d.

[0250] Furthermore, the ends (contours) of the EL layer 103c are processed by photolithography, so they are approximately consistent in the direction perpendicular to the substrate. Similarly, the ends (contours) of the EL layer 103d are processed by photolithography, so they are approximately consistent in the direction perpendicular to the substrate.

[0251] Furthermore, due to the use of photolithography for processing, a gap d exists between the EL layer 103c and the EL layer 103d. Additionally, by using photolithography to process the EL layer, the distance between the first electrode 101c and the first electrode 101d can be made smaller than the distance used during mask evaporation, specifically 0.5 μm or more and 5 μm or less.

[0252] One aspect of the light-emitting device of the present invention utilizes photolithography to process an organic compound layer, allowing for processing with sufficient precision, thereby enabling the manufacture of high-definition display devices. Furthermore, since the photolithography process can be performed on an electron injection layer far from the light-emitting layer without contamination by alkali metals, a light-emitting device with excellent characteristics can be achieved. As described above, the light-emitting device of one aspect of the present invention, having the above-described structure, can realize a high-definition display device and a light-emitting device with excellent characteristics.

[0253] Furthermore, since the organic compound layer of the light-emitting device according to one aspect of the present invention is processed in a single step using photolithography, the contours of the layers included in the organic compound layer are substantially consistent. Here, "substantially consistent" means that the difference between the contour A of layer A and the contour B of layer B included in the organic compound layer is within 5% of the width of the organic compound layer on a line perpendicular to the contour of the compared portion. Additionally, when the end face of the organic compound layer is tapered, continuous variation in the contour is permitted.

[0254] The structure of this embodiment can be used in combination with other structures as appropriate.

[0255] (Implementation Method 3) In this embodiment, a method of using a light-emitting device according to one aspect of the present invention as a display element of a display device is described.

[0256] like Figure 3A and Figure 3B As shown, multiple light-emitting devices 130 are formed on the insulating layer 175 and constitute a display device.

[0257] The display device includes a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. Pixel 178 includes sub-pixels 110R, 110G, and 110B.

[0258] In this specification, for example, when describing the common content among subpixels 110R, 110G, and 110B, they are sometimes referred to as subpixel 110. Similarly, when describing the common content among other constituent elements distinguished by letters, symbols with omitted letters are sometimes used.

[0259] Subpixel 110R emits red light, subpixel 110G emits green light, and subpixel 110B emits blue light. Thus, a full-color image can be displayed on pixel unit 177. In this embodiment, a subpixel of three colors—red (R), green (G), and blue (B)—is used as an example, but combinations of other colors of subpixels can also be used. Furthermore, the number of subpixels is not limited to three; four or more can be used. Examples of four subpixels include: a subpixel of four colors—R, G, B, and white (W); a subpixel of four colors—R, G, B, and Y; and a subpixel of four colors—R, G, B, and infrared (IR); etc.

[0260] 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.

[0261] exist Figure 3A 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.

[0262] A connecting portion 140 may be provided on the outer side of the pixel portion 177, and a region 141 may also be provided thereon. The region 141 is provided between the pixel portion 177 and the connecting portion 140. An EL layer 103 is provided in the region 141. In addition, a conductive layer 151C is provided in the connecting portion 140.

[0263] exist Figure 3A 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. Furthermore, region 141 and connecting portion 140 may be one or more.

[0264] Figure 3B It is along Figure 3A An example of a cross-sectional view of the dashed-dot line A1-A2 in the diagram. For example... Figure 3AAs shown, the display device 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.

[0265] In the pixel section 177, a light-emitting device 130 is disposed on the insulating layer 175 and the plug 176. Furthermore, a protective layer 131 is disposed to cover the light-emitting device 130. A substrate 120 is bonded to the protective layer 131 by a resin layer 122. Additionally, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are preferably disposed between adjacent light-emitting devices 130.

[0266] Figure 3B Cross-sections of multiple inorganic insulating layers 125 and multiple insulating layers 127 are shown, but when viewed from above, the inorganic insulating layers 125 and insulating layers 127 are preferably formed as a single connected layer. In other words, the insulating layer 127 is preferably an insulating layer having an opening on the first electrode.

[0267] exist Figure 3B Light-emitting devices 130R, 130G, and 130B are shown as light-emitting devices 130. Light-emitting devices 130R, 130G, and 130B can emit light of different colors from each other. For example, light-emitting device 130R can emit red light, light-emitting device 130G can emit green light, and light-emitting device 130B can emit blue light. Alternatively, light-emitting devices 130R, 130G, or 130B can also emit other visible or infrared light.

[0268] 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. Furthermore, one aspect of the display device of the present invention may also have a bottom emission structure.

[0269] The light-emitting device 130R has the structure shown in Embodiments 1 and 2. The light-emitting device 130R includes a first electrode 101R (pixel electrode) composed of conductive layers 151R and 152R, an EL layer 103R on the first electrode 101R, and a second electrode 102 (common electrode) 102 on the EL layer 103R. The electron injection layer, which is the outermost surface layer of the EL layer 103R, has the structure described in Embodiment 1. With this structure, damage to the light-emitting layer or active layer during the photolithography process can be suppressed, and good film quality and electrical properties are expected. Furthermore, when the electron transport layer is a mixed layer of an organic compound with electron transport properties and an organic compound with hole transport properties, a display device in which the rise in driving voltage is suppressed can be realized.

[0270] The light-emitting device 130G has the structure shown in Embodiments 1 and 2. The light-emitting device 130G includes a first electrode 101G (pixel electrode) composed of conductive layers 151G and 152G, an EL layer 103G on the first electrode 101G, and a second electrode 102 (common electrode) 102 on the EL layer 103G. The electron injection layer, which is the outermost surface layer of the EL layer 103G, has the structure described in Embodiment 1. With this structure, damage to the light-emitting layer or active layer during the photolithography process can be suppressed, and good film quality and electrical properties are expected. Furthermore, when the electron transport layer is a mixed layer of an organic compound with electron transport properties and an organic compound with hole transport properties, a display device in which the rise in driving voltage is suppressed can be realized.

[0271] The light-emitting device 130B has the structure shown in Embodiments 1 and 2. The light-emitting device 130B includes a first electrode 101B (pixel electrode) composed of conductive layers 151B and 152B, an EL layer 103B on the first electrode 101B, and a second electrode 102 (common electrode) 102 on the EL layer 103B. The electron injection layer, which is the outermost surface layer of the EL layer 103B, has the structure described in Embodiment 1. With this structure, damage to the light-emitting layer or active layer during the photolithography process can be suppressed, and good film quality and electrical properties are expected. Furthermore, when the electron transport layer is a mixed layer of an organic compound with electron transport properties and an organic compound with hole transport properties, a display device in which the rise in driving voltage is suppressed can be realized.

[0272] In a light-emitting device, one of the pixel electrode (first electrode) and the common electrode (second electrode) is used as the anode, and the other is used as the cathode. In this embodiment, unless otherwise specified, it is sometimes assumed that the pixel electrode is used as the anode and the common electrode is used as the cathode.

[0273] EL layers 103R, EL layers 103G, and EL layers 103B are island-shaped layers, either within each light-emitting device or separately according to each emitted color. Note that EL layers 103R, EL layers 103G, and EL layers 103B preferably do not overlap. By arranging the EL layers 103 in an island shape for each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can be suppressed, even 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.

[0274] The island-shaped EL layer 103 is formed by depositing an EL film and processing the EL using photolithography.

[0275] The EL layer 103 is preferably disposed such that it covers the top surface and side surface of the first electrode 101 (pixel electrode) of the light-emitting device 130. This makes it easier to increase the aperture ratio of the display device compared to a structure where the end of the EL layer 103 is located inside the end of the pixel electrode. Furthermore, by covering the side surface of the pixel electrode of the light-emitting device 130 with the EL layer 103, contact between the pixel electrode and the second electrode 102 can be suppressed, thus preventing short circuits in the light-emitting device 130.

[0276] In one aspect of the display device of the present invention, the first electrode 101 (pixel electrode) of the light-emitting device preferably has a stacked structure. For example, in Figure 3B In the example shown, the first electrode 101 of the light-emitting device 130 has a stacked structure of a conductive layer 151 disposed on one side of the substrate 171 and a conductive layer 152 disposed on one side of the EL layer.

[0277] 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 be used.

[0278] 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 including 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 is suitable for use as the conductive layer 152.

[0279] 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.

[0280] Figure 3B The end of the conductive layer 151 preferably has a tapered shape. Specifically, the end of the conductive layer 151 preferably has a tapered shape with a taper angle of less than 90°. At this time, the conductive layer 152 disposed along the side of the conductive layer 151 also has a tapered shape. By making the end of the conductive layer 152 tapered, the coverage of the EL layer 103 disposed along the side of the conductive layer 152 can be improved.

[0281] Furthermore, the ends of conductive layers 151 and 152 may not have a tapered shape; that is, they may be approximately vertical. Additionally, the end of the EL layer 103 is preferably located inside the first electrode 101. This reduces leakage current through the EL layer 103, thereby obtaining a display device with low driving voltage and good display performance.

[0282] In one embodiment of the display device of the present invention, the light-emitting device 130 has the structure shown in Embodiments 1 and 2, thereby realizing a light-emitting device with good reliability.

[0283] Next, referring to Figures 4 to 9, the following describes the product with... Figure 3A An example of a manufacturing method for a display device with the structure shown.

[0284] [Example of manufacturing method] Thin films (insulating films, semiconductor films, and conductive films, etc.) that make up a display device can be formed using sputtering, chemical vapor deposition (CVD), vacuum evaporation, pulsed laser deposition (PLD), or atomic layer deposition (ALD).

[0285] 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 blade coating.

[0286] In addition, when processing the thin film constituting the display device, photolithography can be used, for example.

[0287] 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. Furthermore, immersion lithography can be employed. Additionally, extreme ultraviolet (EUV) light or X-rays can be used as the light for exposure. Furthermore, an electron beam can be used instead of the light used for exposure.

[0288] In the etching of thin films, dry etching, wet etching, or sandblasting methods can be used.

[0289] First, such as Figure 4A As shown, an 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.

[0290] As a substrate, a substrate with heat resistance capable of withstanding the degree of subsequent heat treatment can be used. For example, glass substrates; quartz substrates; sapphire substrates; ceramic substrates; organic resin substrates; or semiconductor substrates such as single-crystal semiconductor substrates or polycrystalline semiconductor substrates made of silicon or silicon carbide, compound semiconductor substrates such as silicon-germanium, SOI substrates, etc.

[0291] Next, as Figure 4A 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.

[0292] Next, as Figure 4A As shown, conductive films 151f, which become conductive layers 151R, 151G, 151B, and 151C, and conductive films 152f, which become conductive layers 152R, 152G, 152B, and 152C, are formed on plug 176 and insulating layer 175. Conductive film 151f can be made of, for example, a metallic material. Conductive film 152f can be made of, for example, an oxide containing one or more of indium, tin, zinc, gallium, titanium, aluminum, and silicon.

[0293] Next, as Figure 4AAs shown, a resist mask 191 is formed on the conductive film 152f. The resist mask 191 can be formed by applying a photosensitive material (photoresist) and then exposing and developing it.

[0294] Next, as Figure 4B As shown, for example, the conductive films 151f and 152f in areas that do not overlap with the resist mask 191 are removed. Thus, conductive layers 151 and 152 are formed.

[0295] Next, as Figure 4C As shown, the resist mask 191 is removed. The resist mask 191 can be removed, for example, by ashing using oxygen plasma.

[0296] Next, as Figure 4D As shown, an insulating film 156f, which will later become insulating layers 156R, 156G, 156B, and 156C, is formed on conductive layers 152R, 152G, 152B, 152C, and insulating layer 175.

[0297] Insulating film 156f can be inorganic insulating films such as oxide insulating film, nitride insulating film, oxynitride insulating film or oxynitride insulating film, for example, silicon oxynitride can be used.

[0298] Next, as Figure 4E As shown, insulating layers 156R, 156G, 156B and 156C are formed by processing insulating film 156f.

[0299] Next, as Figure 5A As shown, an organic compound film 103Rf is formed on conductive layers 152R, 152G, 152B, and insulating layer 175. Furthermore, as... Figure 5A As shown, an organic compound film 103Rf is not formed on the conductive layer 152C.

[0300] Next, as Figure 5A As shown, a sacrificial film 158Rf and a mask film 159Rf are formed.

[0301] By setting a sacrificial film 158Rf 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.

[0302] 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.

[0303] 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 mask film 159Rf is typically 100°C or higher and 200°C or lower, preferably 100°C or higher and 150°C or lower, and more preferably 100°C or higher and 120°C or lower. Since the light-emitting device of one aspect of the present invention comprises a first compound, a display device with good display quality even after a heating process at a higher temperature can be provided.

[0304] The sacrificial film 158Rf and the mask film 159Rf are preferably films that can be removed by wet etching or dry etching.

[0305] Furthermore, the sacrificial film 158Rf, formed by contacting the organic compound film 103Rf, is preferably formed using a method that results in less damage to the organic compound film 103Rf than to the mask film 159Rf. For example, ALD or vacuum evaporation is more preferred than sputtering.

[0306] 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.

[0307] 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 exposure during pattern exposure can be suppressed from reaching the organic compound film 103Rf, thus inhibiting the degradation of the organic compound film 103Rf, which is therefore preferred.

[0308] In addition, metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and silicon-containing indium tin oxide can be used as sacrificial film 158Rf and mask film 159Rf respectively.

[0309] Note that element M (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 in place of gallium in the above metal oxides.

[0310] Semiconductor materials such as silicon or germanium are preferred for use as sacrificial film 158Rf and mask film 159Rf, as they have high affinity with semiconductor manufacturing processes. Alternatively, compounds containing the aforementioned semiconductor materials can be used.

[0311] Various inorganic insulating films can be used as sacrificial film 158Rf and mask film 159Rf. In particular, the oxide insulating film has a higher adhesion to the organic compound film 103Rf than the nitrided insulating film, and is therefore preferred.

[0312] Next, as Figure 5A As shown, a photoresist mask 190R is formed. The photoresist mask 190R can be formed by applying a photosensitive material (photoresist) and then exposing and developing it.

[0313] The resist mask 190R is disposed at a position overlapping with the conductive layer 152R. Preferably, the resist mask 190R is also disposed at a position overlapping with the conductive layer 152C. This can suppress damage to the conductive layer 152C during the manufacturing process of the display device.

[0314] Next, as Figure 5B As 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, a portion of the sacrificial film 158Rf is removed using the mask layer 159R as a mask (also called a hard mask) to form a sacrificial layer 158R.

[0315] 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, it is preferable to use, for example, a developer, an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) aqueous solution, or an acidic aqueous solution such as dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0316] In addition, when dry etching is used in the processing of sacrificial film 158Rf, the degradation of organic compound film 103Rf can be suppressed by not using oxygen-containing gas as etching gas.

[0317] The resist mask 190R can be removed using the same method as the resist mask 191.

[0318] Next, as Figure 5BAs shown, an organic compound film 103Rf is processed to form an EL layer 103R. For example, a mask layer 159R and a sacrificial layer 158R are used as a hard mask and a portion of the organic compound film 103Rf is removed, thereby forming the EL layer 103R.

[0319] Therefore, as Figure 5B As shown, the conductive layer 152R retains a stacked structure of EL layer 103R, sacrificial layer 158R, and mask layer 159R. In addition, conductive layers 152G and 152B are exposed.

[0320] The processing of the organic compound film 103Rf is preferably performed using anisotropic etching. Anisotropic dry etching is particularly preferred. Alternatively, wet etching may also be used.

[0321] 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.

[0322] Alternatively, an oxygen-containing gas can be used as the etching gas. 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.

[0323] When using dry etching, it is preferable to use a gas containing one or more elements from Group 18, such as H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, He, and 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 may also be used as the etching gas.

[0324] Next, as Figure 6A As shown, an organic compound film 103Gf is formed, which will later become the EL layer 103G.

[0325] The organic compound membrane 103Gf can be formed using the same method as that used to form the organic compound membrane 103Rf. Furthermore, the organic compound membrane 103Gf can have the same structure as the organic compound membrane 103Rf.

[0326] Next, as Figure 6A As shown, a sacrificial film 158Gf and a mask film 159Gf are formed sequentially. Then, a resist 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 resist mask 190G are the same as those used for the resist mask 190R.

[0327] The resist mask 190G is positioned at the location where it overlaps with the conductive layer 152G.

[0328] Next, as Figure 6B As shown, a portion of the mask film 159Gf is removed using a photoresist mask 190G, thereby forming a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. Then, the photoresist mask 190G is removed. Next, using the mask layer 159G as a mask, a portion of the sacrificial film 158Gf is removed, thereby forming a sacrificial layer 158G. Then, an organic compound film 103Gf is processed to form an EL layer 103G.

[0329] Next, as Figure 6C As shown, an organic compound film 103Bf is formed.

[0330] The organic compound membrane 103Bf can be formed using the same method as that used to form the organic compound membrane 103Rf. Furthermore, the organic compound membrane 103Bf can have the same structure as the organic compound membrane 103Rf.

[0331] Next, as Figure 6C As shown, a sacrificial film 158Bf and a mask film 159Bf are formed sequentially. Then, a resist mask 190B is formed. The materials and forming 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 forming methods of the resist mask 190B are the same as those used for the resist mask 190R.

[0332] The resist mask 190B is disposed at a position overlapping the conductive layer 152B.

[0333] Next, as Figure 6D As shown, a portion of the mask film 159Bf is removed using a photoresist mask 190B, thereby forming a mask layer 159B. The mask layer 159B remains on the conductive layer 152B. Then, the photoresist mask 190B is removed. Next, using the mask layer 159B as a mask, a portion of the sacrificial film 158Bf is removed, thereby forming a sacrificial layer 158B. Next, the organic compound film 103Bf is processed to form the EL layer 103B. For example, using the mask layer 159B and the sacrificial layer 158B as a hard mask, a portion of the organic compound film 103Bf is removed, thereby forming the EL layer 103B.

[0334] Therefore, as Figure 6D As shown, the stacked structure of EL layer 103B, sacrificial layer 158B, and mask layer 159B remains on conductive layer 152B. In addition, mask layer 159R and mask layer 159G are exposed.

[0335] Note that the side surfaces of EL layers 103R, EL layers 103G, and EL layers 103B are preferably perpendicular to or substantially perpendicular to the surface being formed. For example, the angle formed between the surface being formed and these side surfaces is preferably 60 degrees or more and 90 degrees or less.

[0336] As described above, the distance between two adjacent EL layers in EL layers 103R, EL layers 103G, and EL layers 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 EL layers in EL layers 103R, EL layers 103G, and EL layers 103B. Thus, by reducing the distance between the island-shaped EL layers, a display device with high resolution and a large aperture ratio can be provided. Furthermore, the distance between the first electrodes of adjacent light-emitting devices can 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. Moreover, the distance between the first electrodes of adjacent light-emitting devices is preferably 2 μm or more and 5 μm or less.

[0337] Next, as Figure 7A As shown, it is preferable to remove mask layer 159R, mask layer 159G and mask layer 159B.

[0338] The mask layer removal process can use the same method as the mask layer processing process. In particular, by using wet etching, the damage to the EL layer 103 during mask layer removal can be reduced compared to using dry etching.

[0339] Alternatively, the mask film can be removed by dissolving it in a polar solvent such as water or alcohol. Examples of alcohols include ethanol, methanol, isopropanol (IPA), or glycerol.

[0340] After removing the mask layer, a drying process can be performed to remove surface water. For example, heating treatment can be performed under an inert gas atmosphere or a reduced pressure atmosphere. The heating treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. By using a reduced pressure atmosphere, drying can be performed at a lower temperature, which is preferred.

[0341] Next, as Figure 7B As shown, an inorganic insulating film 125f is formed.

[0342] Next, as Figure 7C As shown, an insulating film 127f, which will later become an insulating layer 127, is formed on an inorganic insulating film 125f.

[0343] 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.

[0344] 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.

[0345] 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.

[0346] 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.

[0347] Next, exposure is performed to sensitize a portion of the insulating film 127f with visible light or ultraviolet light. The insulating layer 127 is formed in the region sandwiched between any two of the conductive layers 152R, 152G, and 152B, and around the conductive layer 152C.

[0348] 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.

[0349] 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).

[0350] Next, as Figure 8A As shown, the exposed areas in the insulating film 127f are removed by developing to form the insulating layer 127a.

[0351] Next, as Figure 8BAs 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.

[0352] 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.

[0353] 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, thin regions of sacrificial layers 158R, 158G, and 158B can be formed with excellent in-plane uniformity.

[0354] 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. Alternatively, a capacitively coupled plasma (CCP) etching apparatus including parallel planar electrodes can be used.

[0355] Furthermore, wet etching is preferred for the first etching process. Compared to dry etching, wet etching reduces damage to the EL layers 103R, EL layers 103G, and EL layers 103B. For example, wet etching can be performed using an alkaline solution. For instance, an aqueous TMAH solution can be used as an alkaline solution in the wet etching of the alumina film. Alternatively, an acidic solution containing fluoride can also be used. 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.

[0356] In the first etching process, the sacrificial layers 158R, 158G, and 158B are not completely removed, and the etching process is stopped when the thickness decreases. In this way, by leaving the corresponding sacrificial layers 158R, 158G, and 158B on the EL layers 103R, 103G, and 103B, damage to the EL layers 103R, 103G, and 103B can be prevented in subsequent processing steps.

[0357] 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 greater than 0 mJ / cm². 2 And it is 800mJ / cm 2 Below, greater 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.

[0358] Here, by having an oxygen-blocking insulating layer (e.g., an aluminum oxide film) as a sacrificial layer 158R, sacrificial layer 158G, and sacrificial layer 158B, oxygen diffusion to EL layer 103R, EL layer 103G, and EL layer 103B can be reduced.

[0359] 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 8C The heat treatment is performed at a temperature lower than the heat resistance temperature of the EL layer. The heat treatment can be performed at a substrate temperature of 50°C 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 either atmospheric or an inert gas atmosphere. Furthermore, the heating atmosphere can be either atmospheric or a reduced pressure atmosphere. 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.

[0360] In the first etching process, by not completely removing the sacrificial layers 158R, 158G, and 158B, leaving them in a thinned state, damage and deterioration of the EL layers 103R, 103G, and 103B can be prevented during the heat treatment. This improves the reliability of the light-emitting device.

[0361] Next, as Figure 9AAs shown, the insulating layer 127 is used as a mask for etching to remove a portion of the sacrificial layers 158R, 158G, and 158B. This creates an opening in each of the sacrificial layers 158R, 158G, and 158B, exposing the top surfaces of the EL layers 103R, 103G, 103B, and the conductive layer 152C. Note that this etching process is sometimes referred to below as the second etching process.

[0362] The ends of the inorganic insulating layer 125 are covered by the insulating layer 127. Furthermore, Figure 9A 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.

[0363] In addition, a second etching process is performed using wet etching. Compared to dry etching, wet etching reduces damage to the EL layers 103R, EL layers 103G, and EL layers 103B. For example, wet etching can be performed using an alkaline or acidic solution. To prevent dissolution of the EL layer 103, wet etching is preferably performed using an aqueous solution.

[0364] Next, as Figure 9B As shown, a common electrode 155 is formed on EL layer 103R, EL layer 103G, EL layer 103B, conductive layer 152C, and insulating layer 127. The common electrode 155 can be formed by methods such as sputtering or vacuum evaporation.

[0365] Next, as Figure 9C 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.

[0366] 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 aspect of the manufacturing method of the display device according to the present invention, the insulating layer 156 is provided in such a way that it overlaps with the side surface of the conductive layer 151, and the conductive layer 152 is formed in such a way that it covers the conductive layer 151 and the insulating layer 156. This improves the yield of the display device and suppresses defects.

[0367] As described above, in one aspect of the manufacturing method of the display device of the present invention, the island-shaped EL layer 103R, island-shaped EL layer 103G, and EL layer 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. Moreover, even with high resolution or aperture ratio and extremely short distances between sub-pixels, contact between EL layers 103R, EL layer 103G, and EL layer 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. In addition, even display devices including tandem light-emitting devices manufactured using photolithography can provide display devices with excellent characteristics.

[0368] (Implementation Method 4) This embodiment describes a display device according to one aspect of the present invention.

[0369] 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 as the display unit of information terminal devices (wearable devices) such as watch-type and bracelet-type devices, as well as the display unit of wearable devices that can be worn on the head, such as head-mounted displays (HMDs) for VR devices and glasses-type AR devices.

[0370] Furthermore, the display device in this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device in this embodiment can be used, for example, as a display unit for devices such as: electronic devices with large screens, such as television sets, 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.

[0371] [Display Module] Figure 10A This is a perspective view of display module 280. Display module 280 includes display device 100A and FPC 290. Note that the display device included in display module 280 is not limited to display device 100A, but can also be any of display devices 100B and 100E, which will be described later.

[0372] 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.

[0373] Figure 10BThis is a three-dimensional schematic diagram of the structure on 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.

[0374] The pixel unit 284 includes a plurality of pixels 284a arranged periodically. Figure 10B The right side shows an enlarged view of pixel 284a. Pixel 284a can adopt various structures described in the above embodiments. Figure 10B This shows an example where pixel 284a has the same structure as pixel 178 shown in FIG3.

[0375] The pixel circuit section 283 includes a plurality of pixel circuits 283a arranged periodically.

[0376] A pixel circuit 283a controls the driving of multiple elements included in a pixel 284a.

[0377] 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. Furthermore, it may include at least one of an arithmetic circuit, a storage circuit, and a power supply circuit.

[0378] The FPC290 is used for wiring to supply video signals or power potentials, etc., from the outside to the circuit section 282. Additionally, ICs can be mounted on the FPC290.

[0379] 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).

[0380] This high-definition display module 280 is suitable for use in VR devices such as HMDs or glasses-type AR devices. For example, because the display module 280 has an extremely high-definition display section 281, even when the display section of the display module 280 is viewed through a lens, the user will not see any pixels, thus achieving a highly immersive display. Furthermore, the display module 280 can also be applied to electronic devices with relatively small display sections.

[0381] [Display Device 100A] Figure 11AThe display device 100A shown includes a substrate 301, light-emitting devices 130R, 130G, 130B, a capacitor 240, and a transistor 310.

[0382] Substrate 301 is equivalent to Figure 10A and Figure 10B 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.

[0383] In addition, a component separation layer 315 is provided between two adjacent transistors 310 in a manner embedded in the substrate 301.

[0384] In addition, an insulating layer 261 is provided to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0385] The capacitor 240 includes a conductive layer 241, a conductive layer 245, and an insulating layer 243 located therebetween. The conductive layer 241 serves as one electrode in the capacitor 240, the conductive layer 245 serves as the other electrode in the capacitor 240, and the insulating layer 243 serves as the dielectric of the capacitor 240.

[0386] 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.

[0387] An insulating layer 255 is provided to cover the capacitor 240, and an insulating layer 174 is provided on the insulating layer 255. Light-emitting devices 130R, 130G, and 130B are provided on the insulating layer 175. Insulators are provided in the areas between adjacent light-emitting devices.

[0388] An insulating layer 156R is provided such that it includes a region overlapping the side surface of conductive layer 151R, an insulating layer 156G is provided such that it includes a region overlapping the side surface of conductive layer 151G, and an insulating layer 156B is provided such that it includes a region overlapping the side surface of conductive layer 151B. Furthermore, a conductive layer 152R is provided such that it covers conductive layer 151R and insulating layer 156R, a conductive layer 152G is provided such that it covers conductive layer 151G and insulating layer 156G, and a conductive layer 152B is provided such that it covers conductive layer 151B and insulating layer 156B. A sacrificial layer 158R is located on EL layer 103R, a sacrificial layer 158G is located on EL layer 103G, and a sacrificial layer 158B is located on EL layer 103B.

[0389] 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 plug 271 embedded in insulating layer 261. The plugs can be made of various conductive materials.

[0390] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A resin layer 122 is attached to the protective layer 131 to bond the substrate 120. 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 10A Substrate 292.

[0391] Figure 11B Show Figure 11A A modified example of the display device 100A shown. Figure 11B 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 11B In the display device shown, the light-emitting device 130 can emit white light, for example. In addition, for example, the color layer 132R, color layer 132G and color layer 132B can transmit red light, green light and blue light, respectively.

[0392] [Display device 100B] Figure 12 A perspective view of the display device 100B is shown. Figure 13 A cross-sectional view of the display device 100B is shown.

[0393] The display device 100B has a structure that bonds substrate 352 and substrate 351. Figure 12 In the image, substrate 352 is represented by a dashed line.

[0394] The display device 100B includes a pixel unit 177, a connection unit 140, a circuit 356, and wiring 355, etc. Figure 12 An example is shown where display device 100B is equipped with IC354 and FPC353. Therefore, it is also possible to... Figure 12 The structure shown is referred to as a display module including a display device 100B, an IC (integrated circuit), and an FPC. Here, the substrate of the display device on which connectors such as the FPC are mounted, or the substrate on which the IC is mounted, is referred to as the display module.

[0395] The connecting portion 140 is disposed on the outer side of the pixel portion 177. There may be one or more connecting portions 140. In the connecting portion 140, the common electrode of the light-emitting device is electrically connected to the conductive layer, and power can be supplied to the common electrode.

[0396] For example, a scan line drive circuit can be used as circuit 356.

[0397] Wiring 355 has the function of supplying signals and power to pixel unit 177 and circuit 356. The signals and power are input to wiring 355 from the outside via FPC 353 or from IC 354.

[0398] Figure 12 An example is shown where IC 354 is mounted on substrate 351 using methods such as COG (Chip On Glass) or COF (Chip On Film). IC 354 can be, for example, an IC including scan line drive circuitry or signal line drive circuitry. Note that the display device 100B and display module do not necessarily need to have an IC mounted on them. Alternatively, the IC can be mounted on an FPC using a COF method, for example.

[0399] Figure 13 An example of a cross-section of a portion of the display device 100B, including a portion of the area of ​​FPC 353, a portion of the circuit 356, a portion of the pixel portion 177, a portion of the connection portion 140, and a portion of the area including the end.

[0400] [Display Device 100C] Figure 13 The display device 100C shown includes transistors 201 and 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B, etc., between substrates 351 and 352.

[0401] For details on light-emitting devices 130R, 130G, and 130B, please refer to Embodiments 1 to 2.

[0402] Light-emitting device 130R includes a conductive layer 224R, a conductive layer 151R on the conductive layer 224R, and a conductive layer 152R on the conductive layer 151R. Light-emitting device 130G includes a conductive layer 224G, a conductive layer 151G on the conductive layer 224G, and a conductive layer 152G on the conductive layer 151G. Light-emitting device 130B includes a conductive layer 224B, a conductive layer 151B on the conductive layer 224B, and a conductive layer 152B on the conductive layer 151B.

[0403] The conductive layer 224R is connected to the conductive layer 222b included in the transistor 205 through an opening provided in the insulating layer 214. The end of the conductive layer 151R is located outside the end of the conductive layer 224R. The insulating layer 156R is provided in such a way that it includes a region that contacts the side of the conductive layer 151R, and the conductive layer 152R is provided in such a way that it covers the conductive layer 151R and the insulating layer 156R.

[0404] The conductive layers 224G, 151G, 152G, 156G, and 152G in the light-emitting device 130G, and the conductive layers 224B, 151B, 152B, 156B, and 152B in the light-emitting device 130B, are the same as the conductive layers 224R, 151R, 152R, 156R, and 152R in the light-emitting device 130R, so detailed descriptions are omitted.

[0405] The conductive layers 224R, 224G, and 224B have recesses formed in a manner that cover the openings provided in the insulating layer 214. These recesses are filled with layer 128.

[0406] Layer 128 has the function of planarizing the recesses of conductive layers 224R, 224G, and 224B. Conductive layers 151R, 151G, and 151B, which are electrically connected to conductive layers 224R, 224G, and 224B, are disposed on conductive layers 224R, 224G, and 224B. Therefore, the area overlapping the recesses of conductive layers 224R, 224G, and 224B can also be used as a light-emitting area, which can improve the pixel aperture ratio.

[0407] Layer 128 can also be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be suitably used for layer 128. In particular, layer 128 is preferably formed using an insulating material, and more preferably using an organic insulating material. Layer 128 can, for example, use the organic insulating material described above that can be used in insulating layer 127.

[0408] A protective layer 131 is provided on light-emitting devices 130R, 130G, and 130B. The protective layer 131 and the substrate 352 are bonded together by an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. The light-emitting device 130 can be sealed using a solid sealing structure or a hollow sealing structure, etc. Figure 13 In this configuration, the space between substrates 352 and 351 is filled with adhesive layer 142, thus employing a solid sealing structure. Alternatively, an inert gas (such as nitrogen or argon) can be used to fill the space, resulting in a hollow sealing structure. In this case, adhesive layer 142 can also be configured not to overlap with the light-emitting device. Furthermore, a resin different from the frame-shaped adhesive layer 142 can be used to fill the space.

[0409] Figure 13 An example is shown below: the connecting portion 140 includes a conductive layer 224C formed by processing a conductive film identical to that of conductive layers 224R, 224G, and 224B; a conductive layer 151C formed by processing a conductive film identical to that of conductive layers 151R, 151G, and 151B; and a conductive layer 152C formed by processing a conductive film identical to that of conductive layers 152R, 152G, and 152B. Furthermore, Figure 13 An example is shown in which the insulating layer 156C is disposed in such a manner that it includes a region that overlaps with the side of the conductive layer 151C.

[0410] Display device 100B is a top-emitting display device. The light-emitting device emits light onto one side of substrate 352. Substrate 352 is preferably made of a material with high transmittance to visible light. When the light-emitting device emits infrared or near-infrared light, a material with high transmittance to those infrared or near-infrared light is preferably used. Pixel electrodes contain a material that reflects visible light, and counter electrodes (common electrodes 155) contain a material that transmits visible light.

[0411] Insulating layers 211, 213, 215, and 214 are sequentially disposed on substrate 351. A portion of insulating layer 211 serves as the gate insulating layer for each transistor. A portion of insulating layer 213 serves as the gate insulating layer for each transistor. Insulating layer 215 is disposed to cover the transistor. Insulating layer 214 is disposed to cover the transistor and serves as a planarization layer. Furthermore, there is no particular limitation on the number of gate insulating layers and the number of insulating layers covering the transistor; there can be one or more.

[0412] Inorganic insulating films are preferably used as insulating layers 211, 213 and 215.

[0413] The insulating layer 214 used as the planarization layer is preferably an organic insulating layer.

[0414] Transistor 201 and transistor 205 include: a conductive layer 221 serving as a gate; an insulating layer 211 serving as a gate insulating layer; conductive layers 222a and 222b serving as source and drain; a semiconductor layer 231; an insulating layer 213 serving as a gate insulating layer; and a conductive layer 223 serving as a gate.

[0415] A connection portion 204 is provided in a region of substrate 351 that is not overlapped with substrate 352. In the connection portion 204, the source or drain electrode of transistor 202 is electrically connected to FPC 372 via conductive layer 166 and connection layer 242. An example is shown where conductive layer 166 has a stacked structure comprising a conductive film formed by processing conductive films identical to conductive layers 224R, 224G, and 224B; a conductive film formed by processing conductive films identical to conductive layers 151R, 151G, and 151B; and a conductive film formed by processing conductive films identical to conductive layers 152R, 152G, and 152B. Conductive layer 166 is exposed on the top surface of connection portion 204. Therefore, connection portion 204 can be electrically connected to FPC 353 via connection layer 242.

[0416] Preferably, a light-shielding layer 157 is provided on the surface of the substrate 352 on the substrate 351 side. The light-shielding layer 157 can be provided between adjacent light-emitting devices, in the connection portion 140, and in the circuit 356, etc. In addition, various optical components can be arranged on the outer side of the substrate 352.

[0417] Substrate 351 and substrate 352 may each be made of a material that can be used in substrate 120.

[0418] As the adhesive layer 142, a material suitable for the resin layer 122 can be used.

[0419] As the connecting layer 242, anisotropic conductive film (ACF) or anisotropic conductive paste (ACP) can be used.

[0420] [Display Device 100D] Figure 14 The display device 100D shown is Figure 13 The main difference between the display device 100C and the display device 100D is that the display device 100D is a bottom-emitting type display device.

[0421] The light emitted by the light-emitting device is directed onto one side of the substrate 351. The substrate 351 is preferably made of a material with high transmittance to visible light. On the other hand, there are no restrictions on the transmittance of the material used for the substrate 352.

[0422] Preferably, a light-shielding layer is formed between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. Figure 14 An example is shown where a light-shielding layer is disposed on a substrate 351, an insulating layer 153 is disposed on the light-shielding layer, and transistors 201, 205, etc. are disposed on the insulating layer 153.

[0423] The light-emitting device 130R includes a conductive layer 112R, a conductive layer 126R on the conductive layer 112R, and a conductive layer 129R on the conductive layer 126R.

[0424] The light-emitting device 130B includes a conductive layer 112B, a conductive layer 126B on the conductive layer 112B, and a conductive layer 129B on the conductive layer 126B.

[0425] The conductive layers 112R, 112B, 126R, 126B, 129R, and 129B all use materials with high transmittance to visible light. The common electrode 155 preferably uses a material that reflects visible light.

[0426] Note that, although Figure 14 The light-emitting device 130G is not shown in the figure, but it is also provided.

[0427] in addition, Figure 14 Examples are shown where the top surface of layer 128 has a flat portion, but there are no particular restrictions on the shape of layer 128.

[0428] [Display Device 100E] Figure 15 The display device 100E shown is Figure 13 The main difference between the display device 100E and the display device 100C is that the display device 100E includes a color layer 132R, a color layer 132G, and a color layer 132B.

[0429] In the display device 100E, the light-emitting device 130 has a region overlapping one of the coloring layers 132R, 132G, and 132B. The coloring layers 132R, 132G, and 132B can be disposed on a surface of the substrate 352 on one side of the substrate 351. The ends of the coloring layers 132R, 132G, and 132B can overlap the light-shielding layer 157.

[0430] In the display device 100E, the light-emitting device 130 can emit white light, for example. Additionally, for example, the color layers 132R, 132G, and 132B can transmit red light, green light, and blue light, respectively. Alternatively, the display device 100E may also employ a structure in which the color layers 132R, 132G, and 132B are disposed between the protective layer 131 and the adhesive layer 142.

[0431] Figure 13 and Figure 15 Examples of layer 128 with a flat portion on the top surface are shown, but there are no particular restrictions on the shape of layer 128.

[0432] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, where multiple structural examples are shown in one embodiment in this specification, these structural examples can be appropriately combined.

[0433] (Implementation Method 5) This embodiment describes an electronic device according to one aspect of the present invention.

[0434] 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 display performance and is easily made high-definition and high-resolution. Therefore, it can be used in the display units of various electronic devices.

[0435] 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.

[0436] 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 such as head-mounted displays for VR, glasses-type AR devices, and MR devices.

[0437] 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).

[0438] Reference Figures 16A to 16DThis illustrates an example of a wearable device that can be worn on the head.

[0439] Figure 16A The electronic device 700A shown and Figure 16B The electronic devices 700B shown include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical components 753, a frame 757, and a pair of nose pads 758.

[0440] 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.

[0441] Both electronic devices 700A and 700B can project the image displayed by the display panel 751 onto the display area 756 in the optical component 753. Because the optical component 753 is light-transmitting, the user can see the image displayed in the display area by overlapping the image seen through the optical component 753.

[0442] 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.

[0443] 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.

[0444] In addition, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly or via wired means, or both.

[0445] The housing 721 can also be equipped with a touch sensor module.

[0446] 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.

[0447] Figure 16C The electronic device 800A shown and Figure 16DThe electronic devices 800B shown include a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0448] 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.

[0449] 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.

[0450] Electronic devices 800A and 800B preferably have a mechanism in which the left and right positions of the lens 832 and the display unit 820 can be adjusted so that the lens 832 and the display unit 820 are in the most suitable position according to the position of the user's eyes.

[0451] Users can use the mounting unit 823 to attach electronic device 800A or electronic device 800B to their head.

[0452] 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.

[0453] Electronic device 800A may also include a vibration mechanism used as a bone conduction headphone.

[0454] Electronic devices 800A and 800B may also include input terminals. Cables supplying image signals from image output devices and the like, as well as power for charging batteries installed within the electronic devices, can be connected to the input terminals.

[0455] The electronic device of one embodiment of the present invention may also have the function of wireless communication with the earphone 750.

[0456] In addition, electronic devices may also include an earphone unit. Figure 16B The illustrated electronic device 700B includes an earphone unit 727. A portion of the wiring connecting the earphone unit 727 and the control unit may also be configured inside the housing 721 or the mounting unit 723.

[0457] same, Figure 16D The illustrated electronic device 800B includes an earphone unit 827. For example, a structure in which the earphone unit 827 and the control unit 824 are connected in a wired manner can be adopted.

[0458] 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.

[0459] Figure 17A The electronic device 6500 shown is a portable information terminal device that can be used as a smartphone.

[0460] Electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0461] 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.

[0462] Figure 17B This is a cross-sectional schematic diagram of one end of the microphone 6506, including the housing 6501.

[0463] A light-transmitting protective member 6510 is provided on one side of the display surface of the housing 6501. The space surrounded by the housing 6501 and the protective member 6510 contains a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc.

[0464] 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).

[0465] 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.

[0466] The display panel 6511 can use a light-emitting 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.

[0467] Figure 17C An example of a television device is shown. In the television device 7100, a display unit 7000 is assembled in a housing 7171. Here is shown a structure in which the housing 7171 is supported by a bracket 7173.

[0468] 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.

[0469] It can be operated using the operating switch provided in the housing 7171 and the separately provided remote control 7151. Figure 17C The operation of the television device 7100 shown.

[0470] Figure 17D An example of a notebook computer is shown. The notebook computer 7200 includes a casing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214, etc. A display unit 7000 is assembled in the casing 7211.

[0471] 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.

[0472] Figure 17E and Figure 17F Here is an example of digital signage.

[0473] Figure 17E The digital sign 7300 shown includes a housing 7301, a display unit 7000, and a speaker 7303. It may also include LEDs, operation keys (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0474] Figure 17F 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.

[0475] exist Figure 17E and Figure 17F 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.

[0476] 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.

[0477] like Figure 17E and Figure 17F As shown, the digital signage 7300 or digital signage 7400 preferably can be linked with the user's smartphone or other information terminal device 7311 or information terminal device 7411 via wireless communication.

[0478] Figures 18A to 18GThe electronic device shown includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), a connection terminal 9006, a sensor 9007 (which has the function of measuring the following factors: 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), a microphone 9008, etc.

[0479] Figures 18A to 18G The electronic device shown has various functions. For example, it may have the following functions: displaying various information (static images, dynamic images, and text images, etc.) on a display unit; touch panel function; displaying calendar, date, or time, etc.; control and processing via various software (programs); wireless communication function; reading and processing programs or data stored in a storage medium; etc.

[0480] The following is a detailed explanation. Figures 18A to 18G The electronic device shown.

[0481] Figure 18A This is a perspective view showing a portable information terminal 9171. The portable information terminal 9171 can be used, for example, as a smartphone. Note that a speaker 9003, a connection terminal 9006, a sensor 9007, etc., may also be included in the portable information terminal 9171. Furthermore, as a portable information terminal 9171, text or image information can be displayed on multiple surfaces. Figure 18A The image shows an example displaying three icons 9050. Alternatively, information 9051, shown as a dashed rectangle, can be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of received emails, SNS messages, phone calls, etc.; the subject line of the email or SNS message; the sender's name; the date; the time; remaining battery level; and radio wave strength. Alternatively, icons 9050 can be displayed in the same location where information 9051 is displayed.

[0482] Figure 18B This is a perspective view showing a portable information terminal 9172. The portable information terminal 9172 has the function of displaying information on three or more surfaces of the display unit 9001. Here, examples are shown where information 9052, information 9053, and information 9054 are displayed on different surfaces. For example, when the portable information terminal 9172 is placed in a jacket pocket, the user can view information 9053 displayed in a position seen from above the portable information terminal 9172.

[0483] Figure 18CThis is a perspective view of a tablet terminal 9173. The tablet terminal 9173 can, for example, execute various application software such as mobile phone, email, and article reading and editing, music playback, network communication, and computer games. The tablet terminal 9173 includes a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of its casing 9000; operation keys 9005 serving as operating buttons on the left side of the casing 9000; and a connection terminal 9006 on the bottom surface.

[0484] Figure 18D This is a perspective view showing a watch-type portable information terminal 9200. The portable information terminal 9200 can be used, for example, as a smartwatch (registered trademark). Furthermore, the display surface of the display unit 9001 is curved, allowing display along its curved surface. In addition, the portable information terminal 9200 can perform hands-free calls, for example, by communicating with a headset capable of wireless communication. Furthermore, by utilizing the connection terminal 9006, the portable information terminal 9200 can transmit data or charge with other information terminals. Charging can also be performed wirelessly.

[0485] Figures 18E to 18G This is a perspective view showing the foldable portable information terminal 9201. Additionally, Figure 18E This is a 3D view of the portable information terminal 9201 in its unfolded state. Figure 18G It is a 3D image of the folded state. Figure 18F From Figure 18E status and Figure 18G The portable information terminal 9201 is a three-dimensional representation of the state transitioning between different states. In its folded state, it offers good portability, while in its unfolded state, it provides a large, seamless display area, resulting in excellent browsing capabilities. The display unit 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by hinges 9055. The display unit 9001 can be bent, for example, within a radius of curvature of 0.1 mm or more and 150 mm or less.

[0486] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, where multiple structural examples are shown in one embodiment in this specification, these structural examples can be appropriately combined.

[0487] [Example 1] In this embodiment, a detailed manufacturing method and characteristics of light-emitting device 1 and light-emitting device 2, which are light-emitting devices according to one aspect of the present invention, and comparative light-emitting device 1, which is a comparative light-emitting device, will be described. The structural formulas of the main compounds used in this embodiment are shown below.

[0488] [Chemical Formula 7] (Manufacturing method of light-emitting device 1) First, a first electrode 101 is formed on a glass substrate by sputtering a 100 nm thick layer of silver (Ag) as a reflective electrode and an 85 nm thick layer of indium tin oxide (ITSO) containing silicon oxide as a transparent electrode, sequentially stacked from one side of the substrate to form a 2 mm × 2 mm dimension. Note that the transparent electrode is used as the anode and, in combination with the aforementioned reflective electrode, is considered as the first electrode 101.

[0489] Next, as a pretreatment for forming light-emitting devices on the substrate, the substrate is washed with water, calcined at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

[0490] Then, the substrate is placed inside and depressurized to 1×10⁻⁶. -4 The substrate is placed in a vacuum evaporation apparatus at approximately Pa and then calcined at 170°C for 30 minutes in the heating chamber of the apparatus, followed by cooling for approximately 30 minutes.

[0491] Next, the substrate is fixed on a support provided in a vacuum evaporation apparatus with the surface on which the first electrode 101 is formed facing down. A hole injection layer 111 is formed on the first electrode 101 by evaporation in a weight ratio of 1:0.03 (=PCBBiF:OCHD-003) of N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) with a molecular weight of 672 containing 4 or more fluorine atoms.

[0492] PCBiF is deposited on the hole injection layer 111 with a thickness of 60 nm to form the hole transport layer 112.

[0493] Next, on the first hole transport layer, 8-(1,1':4',1''-terphenyl-3-yl)-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviated as: 8mpTP-4mDBtPBfpm) as shown in the above structural formula (ii), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as: βNCCP) as shown in the above structural formula (iii), and [2-d3-methyl-8-( A co-evaporation process was performed on 2-pyridyl-κN)benzofurano[2,3-b]pyridin-κC]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κC]iridium(III) (abbreviated as: Ir(5mppy-d3)2(mbfpypy-d3)) with a weight ratio of 0.5:0.5:0.1 (=8mpTP-4mDBtPBfpm:βNCCP:Ir(5mppy-d3)2(mbfpypy-d3)) and a thickness of 40 nm to form the luminescent layer 113.

[0494] Then, 2-{3-[3-(N-phenyl-9H-carbazo-3-yl)-9H-carbazo-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviated as: 2mPCCzPDBq) represented by the above structural formula (v) is vapor-deposited with a thickness of 25 nm, thereby forming an electron transport layer 114.

[0495] After forming the electron transport layer, co-deposition is performed with 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P) as shown in the above structural formula (vi), 4,7-di-1-pyrryl-1,10-phenanthroline (abbreviated as Pyrrd-Phen) as shown in the above structural formula (vii) and indium oxide (In2O3) in a volume ratio of 0.5:0.5:0.1 (=mPPhen2P:Pyrrd-Phen:In2O3) and a thickness of 5 nm, thereby forming the electron injection layer 115.

[0496] The sample, from which the electron-injected layer was formed, was exposed to atmospheric atmosphere for 1 hour. Then, its internal pressure was reduced to 1 × 10⁻⁶. -4 In the heating chamber of a vacuum evaporation device with a pressure of approximately Pa, vacuum baking is performed at 100°C for 60 minutes.

[0497] Then, a co-evaporation process is performed with a silver (Ag) to magnesium (Mg) volume ratio of 1:0.1 and a thickness of 15 nm to form a second electrode 102. Furthermore, a capping layer of 4,4',4''-(phenyl-1,3,5-triyl)tris(dibenzothiophene) (abbreviated as DBT3P-II), represented by the above structural formula (viii), is deposited on the second electrode 102 with a thickness of 70 nm to improve the light extraction efficiency.

[0498] Next, in a glove box under a nitrogen atmosphere, a sealing process is performed using a glass substrate in a manner that prevents the light-emitting device from being exposed to the atmosphere (a UV-curable sealing material is applied around the element, and UV is applied to the sealing material but not to the light-emitting device, and a heat treatment is performed at 80°C for 1 hour under atmospheric pressure), thereby forming the light-emitting device 1.

[0499] (Manufacturing method of light-emitting device 2) The light-emitting device 2 is manufactured in the same way as the light-emitting device 1, except that after the electron transport layer is formed, it is exposed to the atmosphere and vacuum calcined. Then, the electron injection layer, the second electrode and the capping layer are formed.

[0500] (Compare the manufacturing method of light-emitting device 1) In the manufacturing process of light-emitting device 1, after depositing 2mPCCzPDBq with a thickness of 10nm, mPPhen2P with a thickness of 20nm is deposited to form an electron transport layer. Then, atmospheric exposure and vacuum calcination are performed to form a second electrode and a capping layer. Otherwise, it is manufactured in the same way as light-emitting device 1.

[0501] The following shows the device structures of light-emitting device 1, light-emitting device 2, and comparison light-emitting device 1.

[0502] [Table 4] Figure 20 The luminance-current density characteristics of light-emitting device 1, light-emitting device 2, and comparison of light-emitting device 1 are shown. Figure 21 The brightness-voltage characteristics are shown. Figure 22 The current efficiency-current density characteristics are shown. Figure 23 The current density-voltage characteristics are shown. Figure 24 The electroluminescence spectrum is shown. Additionally, Table 5 shows the electroluminescence spectrum at 1000 cd / m². 2 Key characteristics of the surrounding area. Note that luminance, CIE chromaticity, and emission spectrum were measured at room temperature using a spectroradiometer (SR-UL1R, manufactured by Topcon).

[0503] [Table 5] Depend on Figures 20 to 24 As shown in Table 5, the light-emitting devices 1 and 2, which include the organic compound Pyrrd-Phen containing an electron-donating phenanthroline ring and the metal oxide In2O3 in the electron injection layer, exhibit good characteristics of high current efficiency and low driving voltage even when exposed to the atmosphere and subjected to heating treatment during the manufacturing process.

[0504] Furthermore, although light-emitting device 1 undergoes atmospheric exposure and heat treatment (vacuum calcination) after the formation of the electron injection layer, it possesses excellent characteristics equivalent to those of light-emitting device 2, which undergoes atmospheric exposure and heat treatment before the formation of the electron injection layer. Therefore, the electron injection layer comprising the organic compound Pyrrd-Phen containing an electron-donating phenanthroline ring and the metal oxide In2O3 is a layer with high resistance to atmospheric exposure and heat treatment. Thus, light-emitting devices comprising an organic compound containing an electron-donating phenanthroline ring and a metal oxide in the electron injection layer are preferably used as light-emitting devices manufactured through a photolithography process accompanied by atmospheric exposure and heat treatment. Additionally, it is known that in both light-emitting devices 1 and 2, the electron injection layer also includes an organic compound containing a π-electron-deficient heteroaromatic ring, therefore, light-emitting devices 1 and 2 are light-emitting devices with low driving voltages.

[0505] [Example 2] In this embodiment, a detailed manufacturing method and characteristics of light-emitting devices 3 and 4, which are light-emitting devices according to one aspect of the present invention, and comparative light-emitting device 2, which is a comparative light-emitting device, will be described. The structural formulas of the main compounds used in this embodiment are shown below.

[0506] [Chemical Formula 8] (Manufacturing method of light-emitting device 3) First, a first electrode 101 is formed on a glass substrate by sputtering a 100 nm thick layer of silver (Ag) as a reflective electrode and an 85 nm thick layer of indium tin oxide (ITSO) containing silicon oxide as a transparent electrode, sequentially stacked from one side of the substrate to form a 2 mm × 2 mm dimension. Note that the transparent electrode is used as the anode and, in combination with the aforementioned reflective electrode, is considered as the first electrode 101.

[0507] Next, as a pretreatment for forming light-emitting devices on the substrate, the substrate is washed with water, calcined at 200°C for 1 hour, and then subjected to UV ozone treatment for 370 seconds.

[0508] Then, the substrate is placed inside and depressurized to 1×10⁻⁶. -4The substrate is placed in a vacuum evaporation apparatus at approximately Pa and then calcined at 170°C for 30 minutes in the heating chamber of the apparatus, followed by cooling for approximately 30 minutes.

[0509] Next, the substrate is fixed on a support provided in a vacuum evaporation apparatus with the surface on which the first electrode 101 is formed facing down. A hole injection layer 111 is formed by co-evaporation on the inorganic insulating film and the first electrode 101 using N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) with a molecular weight of 672 containing 4 or more fluorine atoms in a weight ratio of 1:0.03 (=PCBBiF:OCHD-003) and a thickness of 10 nm.

[0510] PCBiF is deposited on the hole injection layer 111 with a thickness of 60 nm to form the hole transport layer 112.

[0511] Next, on the first hole transport layer, 8-(1,1':4',1''-terphenyl-3-yl)-4-[3-(dibenzothiophene-4-yl)phenyl]-[1]benzofurano[3,2-d]pyrimidine (abbreviated as: 8mpTP-4mDBtPBfpm) as shown in the above structural formula (ii), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviated as: βNCCP) as shown in the above structural formula (iii), and [2-d3-methyl-8-( A co-evaporation process was performed on 2-pyridyl-κN)benzofurano[2,3-b]pyridin-κC]bis[2-(5-d3-methyl-2-pyridyl-κN2)phenyl-κC]iridium(III) (abbreviated as: Ir(5mppy-d3)2(mbfpypy-d3)) with a weight ratio of 0.5:0.5:0.1 (=8mpTP-4mDBtPBfpm:βNCCP:Ir(5mppy-d3)2(mbfpypy-d3)) and a thickness of 40 nm to form the luminescent layer 113.

[0512] Then, 2-{3-[3-(N-phenyl-9H-carbazo-3-yl)-9H-carbazo-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviated as: 2mPCCzPDBq) represented by the above structural formula (v) is vapor-deposited with a thickness of 25 nm, thereby forming an electron transport layer 114.

[0513] After forming the electron transport layer, co-deposition is performed with 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P) as shown in the above structural formula (vi), 4,7-bis[4-(1-pyrrolidinyl)phenyl]-1,10-phenanthroline (abbreviated as PrdP2Phen) as shown in the above structural formula (ix) and lithium oxide (Li2O) in a volume ratio of 0.5:0.5:0.02 (=mPPhen2P:PrdP2Phen:Li2O) and a thickness of 5 nm, thereby forming the electron injection layer 115.

[0514] The sample, from which the electron-injected layer was formed, was exposed to atmospheric atmosphere for 1 hour. Then, its internal pressure was reduced to 1 × 10⁻⁶. -4 In the heating chamber of a vacuum evaporation device with a pressure of approximately Pa, vacuum baking is performed at 100°C for 60 minutes.

[0515] Then, a co-evaporation process is performed with a silver (Ag) to magnesium (Mg) volume ratio of 1:0.1 and a thickness of 15 nm to form a second electrode 102. Furthermore, a capping layer of 4,4',4''-(phenyl-1,3,5-triyl)tris(dibenzothiophene) (abbreviated as DBT3P-II), represented by the above structural formula (viii), is deposited on the second electrode 102 with a thickness of 70 nm to improve the light extraction efficiency.

[0516] Next, in a glove box under a nitrogen atmosphere, a sealing process is performed using a glass substrate in a manner that prevents the light-emitting device from being exposed to the atmosphere (a UV-curable sealing material is applied around the element, and UV is applied to the sealing material but not to the light-emitting device, and a heat treatment is performed at 80°C for 1 hour under atmospheric pressure), thereby forming the light-emitting device 3.

[0517] (Manufacturing method of light-emitting device 4) The light-emitting device 4 is manufactured in the same way as the light-emitting device 3 after the formation of the electron transport layer, the formation of the electron injection layer, the second electrode and the capping layer.

[0518] (Compare the manufacturing methods of light-emitting device 2) In the manufacturing process of light-emitting device 2, after depositing 2mPCCzPDBq with a thickness of 10nm, mPPhen2P with a thickness of 20nm is deposited to form an electron transport layer. Then, atmospheric exposure and vacuum calcination are performed to form a second electrode and a capping layer. Otherwise, the manufacturing process is the same as that of light-emitting device 3.

[0519] The following shows the device structures of light-emitting device 3, light-emitting device 4, and comparative light-emitting device 2.

[0520] [Table 6] Figure 25 The brightness-current density characteristics of light-emitting devices 3 and 4, and compared with those of light-emitting device 2, are shown. Figure 26 The brightness-voltage characteristics are shown. Figure 27 The current efficiency-current density characteristics are shown. Figure 28 The current density-voltage characteristics are shown. Figure 29 The electroluminescence spectrum is shown. Additionally, Table 7 shows the values ​​for 1000 cd / m². 2 Key characteristics of the surrounding area. Note that luminance, CIE chromaticity, and emission spectrum were measured at room temperature using a spectroradiometer (SR-UL1R, manufactured by Topcon).

[0521] [Table 7] Depend on Figures 25 to 29 As shown in Table 7, the light-emitting devices 3 and 4, which include the organic compound Pyrrd-Phen containing an electron-donating phenanthroline ring and the metal oxide Li2O in the electron injection layer, exhibit good characteristics of high current efficiency and low driving voltage even when exposed to the atmosphere and subjected to heating treatment during the manufacturing process.

[0522] Furthermore, although light-emitting device 3 undergoes atmospheric exposure and heat treatment after the formation of the electron injection layer, it possesses excellent characteristics equivalent to those of light-emitting device 4, which undergoes atmospheric exposure and heat treatment (vacuum calcination) before the formation of the electron injection layer. Therefore, the electron injection layer comprising the organic compound Pyrrd-Phen containing an electron-donating phenanthroline ring and the metal oxide Li2O is a layer with high resistance to atmospheric exposure and heat treatment. Thus, light-emitting devices comprising an organic compound containing an electron-donating phenanthroline ring and a metal oxide in the electron injection layer are preferably used as light-emitting devices manufactured through a photolithography process accompanied by atmospheric exposure and heat treatment. Additionally, it is known that in light-emitting devices 3 and 4, the electron injection layer also includes an organic compound containing a π-electron-deficient heteroaromatic ring, therefore, light-emitting devices 3 and 4 are light-emitting devices with low driving voltages.

[0523] (Example for reference) In this reference example, the synthesis method of 4,7-bis[4-(1-pyrrolyl)phenyl]-1,10-phenanthroline (abbreviated as PrdP2Phen) used in Example 2 is described. The structure of PrdP2Phen is shown below.

[0524] [Chemical Formula 9] <Synthesis of PrdP2Phen> 1.4 g (4.2 mmol) of 4,7-dibromo-1,10-phenanthroline, 2.5 g (9.2 mmol) of 2-[4-(1-pyrrolidinyl)phenyl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 0.48 mL (0.29 mmol) of tricyclohexylphosphine (approx. 18% toluene solution), 3.0 g (14 mmol) of tripotassium phosphate, 25 mL of 1,4-dioxane, and 12 mL of water were placed in a 100 mL three-necked flask, and degassing was carried out by stirring under reduced pressure. 0.12 g (0.13 mmol) of tris(dibenzylideneacetone)dipalladium(0) was added to this mixture, and it was stirred at 100 °C for 12 hours under a nitrogen stream. After stirring, the mixture was cooled to room temperature. The precipitated solid of the mixture was collected by suction filtration. 1,4-dioxane was added to this solid and ultrasonic waves were irradiated, and the solid was collected by suction filtration. Chloroform was added to this solid to dissolve it. Water was added to this solution, and the organic layer was extracted with chloroform. The extract was concentrated to obtain a solid. Toluene was added to this solid and ultrasonic waves were irradiated, and the solid was collected by suction filtration, thereby obtaining a pale yellow solid (1.2 g, yield 60%) of the target product. The following shows the synthesis scheme of PrdP2Phen.

[0525] [Chemical formula 10] The obtained 1.2 g of pale yellow solid was sublimation-purified by the gradient sublimation method. Under the conditions of an argon flow rate of 18 mL / min, a pressure of 3.7 Pa, and a heating temperature of 280 °C, heating was carried out for 20 hours for sublimation purification. As a result, a yellow solid (0.71 g, recovery rate 59%) of the target product was obtained.

[0526] The following shows the utilization of PrdP2Phen after sublimation purification 1 The measurement result of 1H NMR. It was confirmed from this result that PrdP2Phen was obtained.

[0527] 1 1H NMR (CDCl3, 300 MHz): δ = 9.15 (d, J = 4.5 Hz, 2H), 8.00 (s, 2H), 7.54 (d, J = 4.5 Hz, 2H), 7.46 (d, J = 8.7 Hz, 4H), 6.71 (d, J = 8.4 Hz, 4H), 3.41 - 3.37 (m, 8H), 2.09 - 2.04 (m, 8H). [Symbol explanation] 100A: Display device, 100B: Display device, 100C: Display device, 100E: Display device, 100D: Display device, 100: Insulator, 101a: First electrode, 101b: First electrode, 101c: First electrode, 101d: First electrode, 101: First electrode, 101R: First electrode, 101G: First electrode, 101B: First electrode, 102: Second electrode, 103a: EL layer, 103B: EL layer, 103b: EL layer, 103Bf: Organic compound film, 103c: EL layer, 103d: EL layer, 103G: EL layer, 103Gf: Organic compound film, 103R: EL layer, 103Rf: Organic compound film, 1 03: EL layer, 110B: sub-pixel, 110G: sub-pixel, 110R: sub-pixel, 110: sub-pixel, 111a: hole injection layer, 111b: hole injection layer, 111c: hole injection layer, 111d: hole injection layer, 111: hole injection layer, 112: hole transport layer, 112a: hole transport layer, 112b: hole transport layer, 112c_1: hole transport layer, 112c_2: hole transport layer, 112d_1: hole transport layer, 112d_2: hole transport layer, 112R: conductive layer, 112B: conductive layer, 113: emissive layer, 113a: emissive layer, 113b: emissive layer, 113c_1: emissive layer, 113c_2: emissive layer, 113d _1: Emitting layer, 113d_2: Emitting layer, 114: Electron transport layer, 114a: Electron transport layer, 114b: Electron transport layer, 114c_1: Electron transport layer, 114c_2: Electron transport layer, 114d_1: Electron transport layer, 114d_2: Electron transport layer, 115: Electron injection layer, 115a: Electron injection layer, 115b: Electron injection layer, 115c: Electron injection layer, 115d: Electron injection layer, 116: Intermediate layer, 116c: Intermediate layer, 116d: Intermediate layer, 117: P-type layer, 117c: P-type layer, 117d: P-type layer, 118: Electron relay layer, 118c: Electron relay layer, 118d: Electron relay layer, 119: N-type layer, 1 19c: N-type layer, 119d: N-type layer, 120: Substrate, 122: Resin layer, 125f: Inorganic insulating film, 125: Inorganic insulating layer, 126R: Conductive layer, 126B: Conductive layer, 127a: Insulating layer, 127f: Insulating film, 127: Insulating layer, 128: Layer, 129R: Conductive layer, 129B: Conductive layer, 130a: Light-emitting device, 130B: Light-emitting device, 130b: Light-emitting device, 130c: Light-emitting device, 130d: Light-emitting device, 130G: Light-emitting device, 130R: Light-emitting device, 130: Light-emitting device, 131: Protective layer, 132B: Colored layer, 132G: Colored layer, 132R: Colored layer, 140: Connector, 141: Region142: Adhesive layer; 151B: Conductive layer; 151C: Conductive layer; 151f: Conductive film; 151G: Conductive layer; 151R: Conductive layer; 151: Conductive layer; 152B: Conductive layer; 152C: Conductive layer; 152f: Conductive film; 152G: Conductive layer; 152R: Conductive layer; 152: Conductive layer; 153: Insulating layer; 155: Common electrode; 156B: Insulating layer; 156C: Insulating layer; 156f: Insulating film; 156G: Insulating layer; 156R: Insulating layer; 156: Insulating layer; 157: Light-shielding layer; 158B: Sacrificial layer; 158Bf: Sacrificial film; 158G: Sacrificial layer; 158Gf: Sacrificial film; 158R: Sacrificial layer; 158Rf: Sacrificial film. 159B: Mask layer, 159Bf: Mask film, 159G: Mask layer, 159Gf: Mask film, 159R: Mask layer, 159Rf: Mask film, 166: Conductive layer, 171: Insulating layer, 172: Conductive layer, 173: Insulating layer, 174: Insulating layer, 175: Insulating layer, 176: Connector, 177: Pixel part, 178: Pixel, 179: Conductive layer, 190B: Resist mask, 190G: Resist mask, 190R: Resist mask, 191: Resist mask, 201: Transistor, 202: Transistor, 204: Connector, 205: Transistor, 211: Insulating layer, 213: Insulating layer, 214: Insulating layer, 215: Insulating layer, 221: Conductive layer 222a: Conductive layer; 222b: Conductive layer; 223: Conductive layer; 224B: Conductive layer; 224C: Conductive layer; 224G: Conductive layer; 224R: Conductive layer; 231: Semiconductor layer; 240: Capacitor; 241: Conductive layer; 242: Connector layer; 243: Insulating layer; 245: Conductive layer; 254: Insulating layer; 255: Insulating layer; 256: Connector; 261: Insulating layer; 271: Connector; 280: Display module; 281: Display section; 282: Circuit section; 283a: Pixel circuit; 283: Pixel circuit section; 284a: Pixel; 284: Pixel section; 285: Terminal section; 286: Wiring section; 290: FPC; 291: Substrate; 292: Substrate. 301: Substrate; 310: Transistor; 311: Conductive layer; 312: Low-resistance region; 313: Insulating layer; 314: Insulating layer; 315: Component separation layer; 351: Substrate; 352: Substrate; 353: FPC; 354: IC; 355: Wiring; 356: Circuit; 372: FPC; 501: First electrode; 501c: First light-emitting unit; 501d: First light-emitting unit; 502: Second electrode; 502c: Second light-emitting unit; 502d: Second light-emitting unit; 511: First light-emitting unit; 512: Second light-emitting unit; 513: Intermediate layer; 700A: Electronic device; 700B: Electronic device; 721: Housing; 723: Mounting part; 727: Earphone part.750: Headphones; 751: Display panel; 753: Optical components; 756: Display area; 757: Bezel; 758: Nose pad; 800A: Electronic equipment; 800B: Electronic equipment; 820: Display unit; 821: Housing; 822: Communication unit; 823: Mounting unit; 824: Control unit; 825: Imaging unit; 827: Headphone unit; 832: Lens; 6500: Electronic equipment; 6501: Housing; 6502: Display unit; 65 03: Power button; 6504: Button; 6505: Speaker; 6506: Microphone; 6507: Camera; 6508: Light source; 6510: Protective component; 6511: Display panel; 6512: Optical component; 6513: Touch sensor panel; 6515: FPC; 6516: IC; 6517: Printed circuit board; 6518: Battery; 7000: Display unit; 7100: Television unit; 7151: Remote control operator. 7171: Casing; 7173: Stand; 7200: Notebook PC; 7211: Casing; 7212: Keyboard; 7213: Pointing Device; 7214: External Connection Port; 7300: Digital Signage; 7301: Casing; 7303: Speaker; 7311: Information Terminal Equipment; 7400: Digital Signage; 7401: Column; 7411: Information Terminal Equipment; 9000: Casing; 9001: Display Unit; 9002: Camera, 9003: Speaker, 9005: Operation keys, 9006: Connection terminal, 9007: Sensor, 9008: Microphone, 9050: Icon, 9051: Message, 9052: Message, 9053: Message, 9054: Message, 9055: Hinge, 9171: Portable information terminal, 9172: Portable information terminal, 9173: Tablet terminal, 9200: Portable information terminal, 9201: Portable information terminal

Claims

1. A light-emitting device, comprising: First electrode; Second electrode; as well as Organic compound layer, 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 a mixture of metal oxide and a first organic compound. Furthermore, the first organic compound is an organic compound containing a phenanthroline ring having an electron-donating group.

2. A light-emitting device, said light-emitting device being one of a plurality of light-emitting devices included in a group of light-emitting devices, said group of light-emitting devices including: The first electrode group is formed on the same insulating surface; A second electrode opposite to the first electrode group; as well as The first layer group located between the first electrode group and the second electrode, the light-emitting device includes: First electrode; The second electrode; and First floor, The first electrode is one of the first electrode groups. The first electrode is independent in each of the plurality of light-emitting devices. The first layer is one of the first layer groups. The first layer is independent in each of the plurality of light-emitting devices. The second electrode is a continuous conductive layer shared by the plurality of light-emitting devices. The second electrode and the first layer overlap with the first electrode. The first layer includes a light-emitting layer and an electron injection layer. The electron injection layer is a mixture of metal oxide and a first organic compound. The first organic compound is an organic compound containing a phenanthroline ring with an electron-donating group. Furthermore, the distance between the first layer in the light-emitting device and the first layer in other light-emitting devices adjacent to the light-emitting device is more than 0.5 μm and less than 5 μm.

3. The light-emitting device according to claim 1 or 2, The metal oxides thereon are oxides containing any element from Group 1, Group 2, Group 3, Group 11 and Group 13.

4. The light-emitting device according to claim 1 or 2, When the threshold for electron density distribution in the atomic unit system is 0.0004, the minimum electrostatic potential of the first organic compound is below -0.

085.

5. 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.

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

7. 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. Furthermore, the electron-donating group is one or more of alkyl, alkoxy, aryloxy, alkylamino, arylamino, and heterocyclic amino groups.

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

9. The light-emitting device according to claim 1 or 2, The electron-injected layer further contains a second organic compound.

10. The light-emitting device according to claim 9, The second organic compound is an organic compound containing a π-electron-deficient heteroaromatic ring.

11. The light-emitting device according to claim 10, The glass transition temperature of the second organic compound is above 100°C.

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

13. A light-emitting device, comprising: Multiple light-emitting devices, Each of the plurality of light-emitting devices is the light-emitting device described in claim 1 or 2. Each of the plurality of light-emitting devices includes an organic compound layer, the organic compound layer comprising the light-emitting layer and the electron injection layer located between the first electrode and the second electrode. Furthermore, the organic compound layers included in each of the plurality of light-emitting devices are independent among the plurality of light-emitting devices.

Images