Light emitting device

Abstract

The invention provides a light-emitting device which can be used for a high-definition display device. The light-emitting device comprises a first electrode, a second electrode and an organic compound layer, the organic compound layer is located between the first electrode and the second electrode, the organic compound layer comprises a light-emitting layer, an electron transport layer, a first layer and a second layer, the electron transport layer is located between the light-emitting layer and the first layer, and the electron transport layer is located between the light-emitting layer and the first layer. The electron transport layer is in contact with the first layer, the first layer is located between the electron transport layer and the second layer, the first layer has a hole blocking function, the second layer contains at least one of an organic compound having a hole transport property and a substance having an acceptor property, and the electron transport layer is a layer having bipolar.

Description

Technical Field

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

[0002] Note that one aspect of the present invention is not limited to the above technical field. As an example of the technical field of one aspect of the present invention, semiconductor devices, display devices, light-emitting devices, power storage devices, storage devices, electronic devices, lighting devices, input devices (e.g., touch sensors), input / output devices (e.g., touch panels), and driving methods or manufacturing methods of the above devices can be cited. Background Art

[0003] In recent years, display devices have been applied to various uses. For example, as uses of large display devices, research and development have been carried out on home television devices (also called TVs or television receivers), digital signage, and public information displays (PID: Public Information Display), etc., and as uses of small display devices, research and development have been carried out on smartphones or tablet terminals equipped with touch panels, etc.

[0004] At the same time, high definition of display devices is also being carried out. As devices that require high-definition display devices, for example, research and development have been carried out on devices for virtual reality (VR: Virtual Reality), augmented reality (AR: Augmented Reality), substitutional reality (SR: Substitutional Reality), and mixed reality (MR: Mixed Reality).

[0005] As a display element for a display device, the development of light-emitting devices (also called light-emitting elements) has been increasingly active. Light-emitting devices (also called EL devices, EL elements) that utilize the electroluminescence (hereinafter referred to as EL) phenomenon, especially organic EL devices mainly using organic compounds, have the following characteristics: easy to achieve thin and lightweight; capable of responding to input signals at high speed; and capable of being driven by a DC constant voltage power supply, etc., so it is preferably applied to display devices.

[0006] In order to obtain a higher-definition light-emitting device using an organic EL device, a technique of patterning an organic layer by using a photolithography method using a photoresist or the like instead of an evaporation method using a metal mask has been studied. By using the photolithography method, a high-definition display device with an interval of several μm in the EL layer can be obtained (for example, refer to Patent Document 1).

[0007] [Prior Art Documents]

[0008] [Patent Documents]

[0009] [Patent Document 1] Japanese PCT International Application Translation, Publication No. 2018-521459

[0010] [Patent Document 2] International Patent Application Publication No. 2021 / 045178 Summary of the Invention

[0011] Technical Problem to be Solved by the Invention

[0012] In organic EL devices known heretofore, the initial characteristics or reliability of the EL layer are affected when it is exposed to atmospheric components such as water and oxygen. Thus, in common practice, the EL layer is processed in an atmosphere close to vacuum. In particular, when an alkali metal, an alkaline earth metal, or their compounds are used as the electron injection layer, the reactivity of these metals and compounds with water or oxygen is very high. When the surface of the EL layer is exposed to the atmosphere, the electron injection layer rapidly deteriorates and loses its function as an electron injection layer.

[0013] However, in the process of processing using photolithography described above, it is inevitable to expose the surface of the EL layer to the atmosphere.

[0014] Accordingly, an object of one aspect of the present invention is to provide a novel light-emitting device. In addition, an object of another aspect of the present invention is to provide a novel light-emitting device having good efficiency. In addition, an object of one aspect of the present invention is to provide a novel light-emitting device having good reliability. In addition, an object of another aspect of the present invention is to provide a novel light-emitting device having good efficiency and reliability.

[0015] In addition, an object of one aspect of the present invention is to provide a novel light-emitting device manufactured through a photolithography process. In addition, an object of another aspect of the present invention is to provide a novel light-emitting device having good efficiency and manufactured through a photolithography process. In addition, an object of one aspect of the present invention is to provide a novel light-emitting device having good reliability and manufactured through a photolithography process. In addition, an object of another aspect of the present invention is to provide a novel light-emitting device having good luminous efficiency and reliability and manufactured through a photolithography process.

[0016] In addition, an object of one aspect of the present invention is to provide a novel light-emitting device applicable to a high-definition display device. In addition, an object of another aspect of the present invention is to provide a novel light-emitting device having good efficiency and applicable to a high-definition display device. In addition, an object of one aspect of the present invention is to provide a novel light-emitting device having good reliability and applicable to a high-definition display device. In addition, an object of another aspect of the present invention is to provide a novel light-emitting device having good luminous efficiency and reliability and applicable to a high-definition display device.

[0017] One of the objectives of another aspect of the present invention is to provide a display device with high reliability. One of the objectives of another aspect of the present invention is to provide a high-definition display device. Another aspect of the present invention is to provide a high-definition and high-reliability display device.

[0018] In addition, one of the objectives of one aspect of the present invention is to provide a novel organic compound, a novel light-emitting device, a novel display device, a novel display module, and a novel electronic device, respectively.

[0019] Note that the description of these objectives does not preclude the existence of other objectives. One aspect of the present invention does not need to achieve all of the above objectives. Objectives other than the above can be extracted from the description of the specification, drawings, and claims.

[0020] Means for Solving Technical Problems

[0021] One aspect of the present invention is a light-emitting device, which includes a first electrode, a second electrode, and an 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, an electron transport layer, a first layer, and a second layer. The electron transport layer is located between the light-emitting layer and the first layer, and the electron transport layer is in contact with the first layer. The first layer is located between the electron transport layer and the second layer. The first layer has a function of blocking holes. The second layer contains an organic compound having hole-transporting properties and a substance having an acceptor property for the organic compound having hole-transporting properties. The electron transport layer is a layer having bipolarity.

[0022] One aspect of the present invention is a light-emitting device, which includes a first electrode, a second electrode, and an 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, an electron transport layer, a first layer, and a second layer. The electron transport layer is located between the light-emitting layer and the first layer, and the electron transport layer is in contact with the first layer. The first layer is located between the electron transport layer and the second layer. The first layer has a function of blocking holes. The second layer contains an organic compound having hole-transporting properties and a substance having an acceptor property for the organic compound having hole-transporting properties. The HOMO energy level of the organic compound having the highest HOMO energy level among the organic compounds contained in the electron transport layer is -5.90 eV or more and -5.00 eV or less.

[0023] One embodiment of the present invention is a light-emitting device including a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer, an electron transport layer, a first layer, and a second layer. The electron transport layer is located between the light-emitting layer and the first layer and is in contact with the first layer. The first layer is located between the electron transport layer and the second layer. The first layer contains an organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more. The second layer contains an organic compound having a hole-transporting property and a substance having an acceptability for the organic compound having a hole-transporting property. The HOMO level of the organic compound having the highest HOMO level among the organic compounds contained in the electron transport layer is -5.90 eV or more and -5.00 eV or less.

[0024] In addition, another embodiment of the present invention is a light-emitting device having the above structure, wherein the first layer preferably contacts the second layer.

[0025] In addition, another embodiment of the present invention is a light-emitting device having the above structure, wherein the distance between the first layer and the second layer is preferably 1 nm or more and 10 nm or less.

[0026] In addition, another embodiment of the present invention is a light-emitting device having the above structure, wherein the LUMO level of the organic compound having the lowest LUMO level among the organic compounds contained in the first layer is preferably -3.15 eV or more and -2.50 eV or less.

[0027] In addition, another embodiment of the present invention is a light-emitting device having the above structure, wherein the LUMO level of the organic compound having the lowest LUMO level among the organic compounds contained in the electron transport layer is preferably -3.15 eV or more and -2.50 eV or less.

[0028] In addition, another embodiment of the present invention is a light-emitting device having the above structure, wherein the electron transport layer preferably contains an organic compound having an electron-transporting skeleton and a hole-transporting skeleton.

[0029] In addition, another embodiment of the present invention is a light-emitting device having the above structure, wherein the electron transport layer preferably contains an organic compound having an electron-transporting skeleton and an organic compound having a hole-transporting skeleton.

[0030] In addition, another embodiment of the present invention is a light-emitting device having the above structure, wherein the electron-transporting skeleton is preferably a π-deficient heteroaromatic ring, and the hole-transporting skeleton is preferably a π-rich heteroaromatic ring.

[0031] Further, another aspect of the present invention is a light-emitting device having the above structure, wherein an organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more preferably does not have an electron-transporting skeleton.

[0032] Further, another aspect of the present invention is a light-emitting device having the above structure, wherein an organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more preferably has a guanidine skeleton.

[0033] Further, another aspect of the present invention is a light-emitting device having the above structure, wherein an organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more preferably has a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton.

[0034] Further, another aspect of the present invention is a light-emitting device having the above structure, wherein the first layer preferably contains an organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more and an organic compound having electron-transporting properties.

[0035] Further, another aspect of the present invention is a light-emitting device having the above structure, wherein the organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more preferably does not have an electron-donating property with respect to the organic compound having electron-transporting properties.

[0036] Further, another aspect of the present invention is a light-emitting device having the above structure, wherein the spin density measured by electron spin resonance method of the first layer is preferably 1×10 17 spins / cm 3 or less.

[0037] Further, another aspect of the present invention is a light-emitting device having the above structure, wherein the LUMO energy level of the organic compound having electron-transporting properties is preferably -3.00 eV or more and -2.00 eV or less.

[0038] Further, another aspect of the present invention is a light-emitting device having the above structure, wherein the second layer is preferably a charge generation layer.

[0039] Further, another aspect of the present invention is a light-emitting device having the above structure, wherein the second layer is preferably: a mixed layer of an organic compound having hole-transporting properties and a substance having an acceptor property with respect to the organic compound having hole-transporting properties; or a laminate of single films of an organic compound having hole-transporting properties and a substance having an acceptor property with respect to the organic compound having hole-transporting properties.

[0040] Further, another aspect of the present invention is a light-emitting device having the above structure, wherein the spin density measured by electron spin resonance method of the second layer is preferably 1×10 17spins / cm 3 The above.

[0041] In addition, another aspect of the present invention is a light-emitting device having the above structure, wherein the second layer preferably contacts the first electrode or the second electrode.

[0042] In addition, another aspect of the present invention is a light-emitting device having the above structure, the light-emitting device further including a third layer, wherein the light-emitting layer is preferably located between the third layer and the electron transport layer, and the third layer preferably contains a second hole-transporting organic compound and a substance having an acceptor property with respect to the second hole-transporting organic compound.

[0043] In addition, another aspect of the present invention is a light-emitting device having the above structure, wherein the first layer is preferably a mixed layer of a hole-transporting organic compound and a substance having an acceptor property with respect to the hole-transporting organic compound.

[0044] Another aspect of the present invention is a display module including at least one of the above light-emitting device, a connector, and an integrated circuit.

[0045] Another aspect of the present invention is an electronic device including at least one of the above light-emitting device, a housing, a battery, a camera, a speaker, and a microphone.

[0046] Advantages of the Invention

[0047] According to one aspect of the present invention, a novel light-emitting device can be provided. In addition, according to another aspect of the present invention, a novel light-emitting device having good efficiency can be provided. In addition, according to one aspect of the present invention, a novel light-emitting device having good reliability can be provided. In addition, according to another aspect of the present invention, a novel light-emitting device having good reliability and efficiency can be provided.

[0048] In addition, according to one aspect of the present invention, a novel light-emitting device manufactured by a photolithography process can be provided. In addition, according to another aspect of the present invention, a novel light-emitting device having good efficiency manufactured by a photolithography process can be provided. In addition, according to one aspect of the present invention, a novel light-emitting device having good reliability manufactured by a photolithography process can be provided. In addition, according to another aspect of the present invention, a novel light-emitting device having good reliability and luminous efficiency manufactured by a photolithography process can be provided.

[0049] In addition, according to one aspect of the present invention, a novel light-emitting device that can be used in a high-definition display device can be provided. In addition, according to another aspect of the present invention, a novel light-emitting device with good efficiency that can be used in a high-definition display device can be provided. In addition, according to one aspect of the present invention, a novel light-emitting device with good reliability that can be used in a high-definition display device can be provided. In addition, according to another aspect of the present invention, a novel light-emitting device with good efficiency and reliability that can be used in a high-definition display device can be provided.

[0050] In addition, according to one aspect of the present invention, a display device with high definition and high luminous efficiency can be provided. In addition, according to one aspect of the present invention, a display device with high resolution and good display performance can be provided. In addition, according to one aspect of the present invention, a display device with good display quality and display performance can be provided. In addition, according to one aspect of the present invention, a display device with high definition, high luminous efficiency, and high reliability can be provided. In addition, according to one aspect of the present invention, a display device with high resolution, good display performance, and high reliability can be provided. In addition, according to one aspect of the present invention, a display device with good display quality, good display performance, and high reliability can be provided.

[0051] In addition, a novel display device, a novel display module, and a novel electronic device can be provided.

[0052] Note that the description of these effects does not preclude the existence of other effects. One aspect of the present invention does not necessarily have all of the above effects. Effects other than the above can be extracted from the descriptions in the specification, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1A and Figure 1B is a drawing for explaining the driving mechanism of the light-emitting device of the present invention.

[0054] Figure 2A and Figure 2B is a drawing showing the light-emitting device.

[0055] Figure 3A and Figure 3B is a drawing showing the light-emitting device.

[0056] Figure 4 is a drawing showing the light-emitting device.

[0057] Figure 5A and Figure 5B are a top view and a cross-sectional view of the light-emitting device.

[0058] Figure 6 is a cross-sectional view of the light-emitting device.

[0059] Figures 7A to 7E It is a cross-sectional view showing an example of a manufacturing method of a display device.

[0060] Figures 8A to 8D It is a cross-sectional view showing an example of a manufacturing method of a display device.

[0061] Figures 9A to 9D It is a cross-sectional view showing an example of a manufacturing method of a display device.

[0062] Figures 10A to 10C It is a cross-sectional view showing an example of a manufacturing method of a display device.

[0063] Figures 11A to 11C It is a cross-sectional view showing an example of a manufacturing method of a display device.

[0064] Figures 12A to 12C It is a cross-sectional view showing an example of a manufacturing method of a display device.

[0065] Figure 13A and Figure 13B It is a perspective view showing an example of the structure of a display module.

[0066] Figure 14A and Figure 14B It is a cross-sectional view showing an example of the structure of a display device.

[0067] Figure 15 It is a perspective view showing an example of the structure of a display device.

[0068] Figure 16 It is a cross-sectional view showing an example of the structure of a display device.

[0069] Figure 17 It is a cross-sectional view showing an example of the structure of a display device.

[0070] Figure 18 It is a cross-sectional view showing an example of the structure of a display device.

[0071] Figures 19A to 19D It is a diagram showing an example of an electronic device.

[0072] Figures 20A to 20F It is a diagram showing an example of an electronic device.

[0073] Figures 21A to 21G It is a diagram showing an example of an electronic device. Detailed implementation mode

[0074] 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 it is easily understandable for those of ordinary skill in the art that its mode and details can be changed into various forms without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited only to the content described in the embodiments shown below.

[0075] Note that in this specification and the like, a device manufactured using a metal mask or an FMM (Fine Metal Mask, high-precision metal mask) is sometimes referred to as a device having an MM (Metal Mask) structure. In addition, in this specification and the like, a device not manufactured using a metal mask or an FMM is sometimes referred to as a device having an MML (Metal Mask Less) structure.

[0076] (Embodiment 1)

[0077] The light-emitting device includes a charge generation layer (Carrier Generation Layer: CGL) between a pair of electrodes and between the electron transport layer and the cathode. The CGL is a layer in which electrons and holes are generated by charge separation by applying a voltage. As the CGL, a layer formed by mixing a material having carrier transport properties and a substance having acceptor properties and a layer formed by mixing a material having carrier transport properties and a substance having donor properties are generally used. For example, as the CGL, a layer containing an organic compound having hole transport properties and a substance having acceptor properties and a layer containing an organic compound having electron transport properties and a material having donor properties are used.

[0078] In addition, as the CGL, by laminating a layer containing an organic compound having hole transport properties and a substance having acceptor properties (CGL1) and a layer containing an organic compound having electron transport properties and a substance having donor properties (CGL2), it is easy to inject electrons into the electron transport layer and the driving voltage drops, so it is preferable. Note that CGL1 is formed on the cathode side and CGL2 is formed on the anode side. By injecting the holes generated in CGL1 into the cathode side and injecting the electrons generated in CGL2 into the electron transport layer, the injection barrier of the carriers can be reduced. In addition, since the substance having acceptor properties is stable, a light-emitting device with good reliability can be realized. Note that CGL2 can also be a single film of a substance having donor properties. At this time, the substance having donor properties performs charge separation with the electron transport material, so it can be regarded as injecting electrons into the electron transport layer during charge separation. Note that there may be a tunneling current flowing between CGL1 and CGL2 or the layers may be mixed and recombined.

[0079] As one of the methods for forming an organic semiconductor film into a specified shape, vacuum evaporation using a metal mask (mask evaporation) is widely employed. However, with the progress of high density and high definition, due to various reasons typified by problems such as alignment accuracy and the spacing from the substrate, the high definition of mask evaporation is approaching its limit. On the other hand, it is desired to realize an organic semiconductor device with a denser pattern by processing the shape of the organic semiconductor film using photolithography. Moreover, photolithography is more easily scalable to large areas compared to mask evaporation, and thus research on processing organic semiconductor films using photolithography is underway.

[0080] On the other hand, it has been known that in light-emitting devices (organic EL devices) mainly using organic compounds, the initial characteristics or reliability of the EL layer are affected when exposed to atmospheric components such as water and oxygen, and the EL layer is processed in an atmosphere approximated to vacuum in common steps.

[0081] In particular, in many cases, the electron injection layer and CGL2 of organic EL devices use alkali metals, alkaline earth metals, or their compounds (hereinafter, also referred to as Li compounds, etc.). The above-mentioned Li compounds, etc. have high reactivity with water or oxygen and instantaneously deteriorate when exposed to the atmosphere, and thus do not function as the electron injection layer and CGL2.

[0082] However, in the process of processing using photolithography as described above, the surface of the EL layer has to be exposed to the atmosphere, and thus the electron injection property of the electron injection layer and CGL2 using Li compounds, etc. significantly decreases.

[0083] Here, the present inventors have found that, for example, a light-emitting device including a novel layer containing an organic compound having strong basicity such as 1-(9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2hppSF) instead of the above CGL2 can have good characteristics.

[0084] The above-mentioned organic compound having strong basicity is not easily deteriorated by exposure to the atmosphere like alkali metals, alkaline earth metals, or their compounds. Therefore, even in a light-emitting device processed by a photolithography process having an atmospheric exposure in the process, deterioration of the light-emitting device due to deterioration of the organic compound having strong basicity itself is not likely to occur.

[0085] Note that, on the other hand, when comparing devices always manufactured under vacuum, the driving voltage of a light-emitting device including a novel layer containing an organic compound having strong basicity is higher than that of a light-emitting device including CGL2 using alkali metals, alkaline earth metals, or their compounds.

[0086] Due to these facts and various additional experiments, the present inventors have found that in a light-emitting device including a novel layer containing an organic compound having a strong basicity, by making the electron transport layer bipolar, a novel light-emitting device can be fabricated which has resistance to processing in the atmosphere, good reliability, and a low driving voltage. Further, in a light-emitting device according to one embodiment of the present invention, a CGL1 containing a substance having an acceptability is provided between the above-described novel layer and the cathode. Since a substance having an acceptability is known to be a material stable in the atmosphere, even when the light-emitting device is exposed to the atmosphere during the manufacturing process of the light-emitting device, deterioration caused by oxidation or the like of the light-emitting device can be suppressed, and thus a light-emitting device with better reliability can be fabricated.

[0087] Hereinafter, the mechanism of a light-emitting device including a novel layer containing an organic compound having a strong basicity and a light-emitting device according to one embodiment of the present invention will be described.

[0088] Different from alkali metals or alkaline earth metals typified by Li compounds or their compounds, an organic compound having a strong basicity is not used as a donor, and charge separation does not occur in the novel layer including the organic compound, and thus electrons supplied to the electron transport layer are not generated. Accordingly, in the present specification, the novel layer containing an organic compound having a strong basicity is referred to as a "donor-less layer (DLL)".

[0089] Note that, also in this case, holes and electrons are generated in CGL1 as Figure 1A described. Generally, the difference between the lowest unoccupied molecular orbital (LUMO) energy level (LUMO ETM ) of an organic compound having electron transport properties and the LUMO energy level (LUMO AC ) of a substance having an acceptability is large. Therefore, the potential difference between the LUMO energy levels of the substance having an acceptability in CGL1 and the organic compound having electron transport properties in the DLL is large, and electrons generated in CGL1 cannot be injected into the DLL, and thus it is difficult to inject electrons having electron transport properties.

[0090] Thus, in a light-emitting device including a DLL instead of CGL2, the DLL is not used as a charge generation layer, and thus the increase in the driving voltage is significant.

[0091] Accordingly, the present inventors have found that by making the electron transport layer in contact with the DLL a bipolar layer, a light-emitting device including the DLL can be used as a light-emitting device without significantly increasing the driving voltage.

[0092] This can be explained based on the driving mechanism of the following light-emitting device: new knowledge that electrons flow through the DLL but holes are blocked (do not flow through); the generation of an electric dipole due to the accumulation of charges; and the resulting drift of the vacuum level.

[0093] First, even when a voltage is applied to a light-emitting device including a DLL instead of a CGL2 as described above, the DLL is not used as a CGL, so no electrons are generated. On the other hand, holes injected from the anode accumulate rapidly at the interface on the electron transport layer side in the DLL as Figure 1B in 400. This is because in the light-emitting device of one embodiment of the present invention, by including a strongly basic organic compound having an acid dissociation constant pKa of 8 or more in the DLL, holes are captured and blocked, and the electron transport layer has bipolarity, whereby holes can be transferred from the anode side to the DLL.

[0094] Due to the application of voltage and the accumulation of holes at the interface on the electron transport layer side in the DLL, electrons are induced by the CGL1. In the initial state, the difference in the LUMO levels between the acceptor-like substance contained in the CGL1 and the electron-transporting organic compound contained in the DLL is large, so the electrons induced by the CGL1 are not injected into the DLL but accumulate at the interface on the DLL side in the CGL1 ( Figure 1B in 401) (note that when the DLL does not contain an electron-transporting organic compound, i.e., a single film of a strongly basic organic compound, the electrons generated in the CGL1 accumulate on the side of the single film of the strongly basic organic compound). Then, the accumulated electrons and the holes accumulated at the interface on the electron transport layer side in the DLL together form an electric double layer, and an electric dipole is generated ( Figure 1B in 402).

[0095] As a result, the vacuum level drifts ( Figure 1B in 403), the LUMO levels of the acceptor-like substance contained in the CGL1 and the electron-transporting organic compound of the DLL approach, and the electrons generated in the CGL1 are injected into the DLL ( Figure 1B in 404). Then, the electrons injected into the DLL reach the light-emitting layer and recombine, so light emission is obtained, and thus the light-emitting device of one embodiment of the present invention can be used as a light-emitting device.

[0096] Note that, generally speaking, from the viewpoints of luminous efficiency and reliability, it is not preferable that holes passing through the light-emitting layer flow through the electron transport layer. Therefore, a material with electron transport properties (in other words, a material with low hole transport properties) is selected as the material constituting the electron transport layer, and in many cases, a hole blocking layer is provided in contact with the light-emitting layer between the light-emitting layer and the electron transport layer. However, contrary to this, the light-emitting device according to one embodiment of the present invention can provide a light-emitting device with good characteristics by making the electron transport layer bipolar.

[0097] Note that, in a light-emitting device having a general structure in which the electron transport layer is not bipolar (the electron transport layer does not transport or block holes), the position where holes accumulate is the interface on the electron transport layer side. Therefore, the accumulation positions of holes and electrons are far apart. Thus, when comparing under the condition of the same amount of charge accumulation, the driving voltage of the light-emitting device having a general structure increases because the electric field of the electric dipole is weak.

[0098] The electron transport layer is preferably a layer having bipolarity as described above, that is, an electron transport layer having high hole transport properties. Therefore, the highest occupied molecular orbital (HOMO) energy level of the organic compound in the electron transport layer is preferably -5.90 eV or more and -5.00 eV or less, more preferably -5.80 eV or more and -5.00 eV or less, and still more preferably -5.70 eV or more and -5.15 eV or less. In addition, since the electron transport layer also needs to have good electron transport properties, the lowest unoccupied molecular orbital (LUMO) energy level of the organic compound in the electron transport layer is preferably -3.15 eV or more and -2.50 eV or less, more preferably -3.00 eV or more and -2.70 eV or less.

[0099] The electron transport layer may also be a layer composed of multiple organic compounds. When the electron transport layer contains multiple organic compounds, the HOMO energy level of the organic compound having the highest HOMO energy level is preferably within the above range. In addition, when the electron transport layer contains multiple organic compounds, the LUMO energy level of the organic compound having the lowest LUMO energy level is preferably within the above range. In addition, when the electron transport layer is composed of multiple organic compounds, it is preferable that at least one of them is an organic compound having electron transport properties and at least one is an organic compound having hole transport properties.

[0100] Note that the organic compound with electron-transporting property and the organic compound with hole-transporting property are preferably one organic compound. That is to say, the electron transport layer more preferably contains an organic compound having both electron-transporting property and hole-transporting property, and thus it is easy to obtain a light-emitting device with good characteristics.

[0101] As the organic compound with electron-transporting property or the organic compound having both electron-transporting property and hole-transporting property, it is preferable to use a substance with an electron mobility of 1×10 -7 cm 2 / Vs or more when the square root of the electric field strength [V / cm] is 600. More preferably, a substance with an electron mobility of 1×10 -6 cm 2 / Vs or more is used. In addition, as the organic compound with hole-transporting property or the organic compound having both electron-transporting property and hole-transporting property, it is preferable to use a substance with a hole mobility of 1×10 -7 cm 2 / Vs or more when the square root of the electric field strength [V / cm] is 600. More preferably, a substance with a hole mobility of 1×10 -6 cm 2 / Vs or more is used.

[0102] In addition, the electron transport layer preferably contains an organic compound with electron-transporting property having an acid dissociation constant pKa of 4 or less. In addition, the electron transport layer preferably contains an organic compound having a hole-transporting skeleton.

[0103] In addition, the electron transport layer preferably contains an organic compound having an electron-transporting skeleton and an organic compound having a hole-transporting skeleton. Note that the organic compound having an electron-transporting skeleton and the organic compound having a hole-transporting skeleton are preferably one organic compound. That is to say, the electron transport layer more preferably contains an organic compound having both an electron-transporting skeleton and a hole-transporting skeleton, and thus it is easy to obtain a light-emitting device with good characteristics.

[0104] Note that the electron-transporting skeleton is preferably a skeleton having a π-deficient heteroaromatic ring. As the skeleton having a π-deficient heteroaromatic ring, for example, a skeleton containing at least any one of a polyazole skeleton, a pyridine skeleton, a diazine skeleton, and a triazine skeleton in the ring is preferably used. Specifically preferred are a pyrimidine skeleton, a pyrazine skeleton, a pyridazine skeleton, a pyridine skeleton, a triazine skeleton, a benzofuro[2,3-d]pyrimidine skeleton, a benzothieno[2,3-d]pyrimidine skeleton, a benzofuro[2,3-b]pyrazine skeleton, a benzothieno[2,3-b]pyrazine skeleton, etc. Particularly preferred are a pyrimidine skeleton, a pyrazine skeleton, a triazine skeleton, and a benzofuro[2,3-d]pyrimidine skeleton. In addition, the hole-transporting skeleton is preferably a skeleton having a π-rich heteroaromatic ring. As the π-rich heteroaromatic ring, for example, a fused aromatic ring containing at least any one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton in the ring is preferably used. Specifically preferred are a carbazole skeleton, a dibenzothiophene skeleton, or a skeleton in which these skeletons are further fused with an aromatic ring or a heteroaromatic ring. Particularly preferred are a carbazole skeleton, a biscarbazole skeleton, and an indolocarbazole skeleton. In addition, an amine skeleton, particularly a triphenylamine skeleton, is also preferably used.

[0105] As the organic compound constituting the electron-transporting layer, an organic compound having both an electron-transporting skeleton and a hole-transporting skeleton is preferably used. Specifically, as such an organic compound, 3,6-bis(diphenylamino)-9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9H-carbazole (abbreviation: DACT-II), 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenz[f,h]quinoxaline (abbreviation: 2mPCCzPDBq), 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 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), etc. can be mentioned.

[0106] In addition, the organic compound constituting the electron-transporting layer preferably emits thermally activated delayed fluorescence (TADF) (has TADF property). The organic compound having TADF property has a high HOMO energy level, a low LUMO energy level, and short excited lifetimes of both singlet and triplet states. Therefore, when recombination occurs in the electron-transporting layer, the excited state can be inactivated rapidly, and a light-emitting device with good reliability can be provided. As the organic compound having TADF property that is preferably used when constituting the electron-transporting layer, DACT-II can be mentioned.

[0107] In addition, when the electron transport layer is composed of a plurality of organic compounds, examples of organic compounds having electron transport properties include: 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviated as: CO11), 2,2',2"-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) ( organic compounds having an azole skeleton, such as 2-[3-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviated as BzOs); 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviated as 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviated as TmPyPB), bathophenanthroline (abbreviated as Bphen), bathocuproin (abbreviated as BCP), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBphen), 2,2'-(1, Organic compounds containing a heteroaromatic ring having a pyridine skeleton, such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBTPhen), 2-[4-(9-phenanthrenyl)-1-naphthyl]-1,10-phenanthroline (abbreviated as: PnNPhen), and 2-[4-(2-triphenylyl)phenyl]-1,10-phenanthroline (abbreviated as: pTpPPhen); 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBTPhen); DBq-II), 2-[3-(3'-dibenzothiophene-4-yl)biphenyl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mpPCBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2CzPDBq-III), 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]Quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(Dibenzothiophen-4-yl)phenyl]dibenz[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(Dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[(3'-Dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-Bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-Bis[3-(4-dibenzothiophenyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-Bis[3-(9H-carbazol-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-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-Bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-Bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(Dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-Binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2'-(Pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(Pyridine-2,6-diyl)bis{4-[4-(naphthalen-2-yl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(Biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-Bis(4-naphthalen-1-ylphenyl)-4-[4-(pyridin-3-yl)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'-spirobi[9H-fluorene]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-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 (abbreviation: mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(dibenzothiophen-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-phenanthryl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenylindolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3'-(triphenylene-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',1”-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), etc., which are organic compounds containing a heteroaromatic ring having a triazine skeleton. Organic compounds containing a heteroaromatic ring having a diazine skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, or organic compounds containing a heteroaromatic ring having a triazine skeleton have good reliability and are therefore preferred. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties, which contribute to reducing the driving voltage.

[0108] In addition, when the electron transport layer is composed of multiple organic compounds, examples of the organic compound having hole transporting properties include N-(4-biphenyl)-6, N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophene-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthalen-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthalen-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthalen-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthalen-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthalen-2-yl)-triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthalen-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthalen-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'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi-9H-fluorene-4-amine, N,N-bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-Spirobi-9H-fluorene-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), etc.

[0109] Note that the thickness of the electron transport layer is preferably thin, but a light-emitting device with good reliability can be manufactured when its thickness is 5 nm to 10 nm, so it is preferred.

[0110] DLL accumulates holes injected from the anode. Therefore, DLL is a layer having a function of blocking holes or a layer that does not transport holes. In addition, DLL needs to transport electrons injected from CGL1 and inject them into the electron transport layer. Therefore, DLL is a layer having electron transport properties.

[0111] By manufacturing an electronic device through which only holes flow (hereinafter referred to as a single-hole device) and measuring the relationship between current density and voltage, it can be determined whether DLL is a layer that blocks holes or a layer that does not transport holes. For example, when the current density significantly decreases when the layer to be held by the single-hole device as shown in Table 1 is held, specifically, when the current density at 10 V is 0.01 mA / cm when measuring while holding the layer to be measured by the device shown in Table 1 2 In the following cases, the layer of interest can be regarded as a hole-blocking layer.

[0112] [Table 1]

[0113]

[0114] Note that in the table, ITSO refers to indium tin oxide containing silicon oxide, PCBBiF refers to N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine, and OCHD-003 refers to an electron acceptor material containing fluorine and having a molecular weight of 672.

[0115] By using such a device, it is possible to compare the relationship between the current density and the voltage when layer 3 is not formed with the relationship between the current density and the voltage when layer 3 is formed as a layer with an object of 10 nm. When measuring by sandwiching a layer with an object of 10 nm as layer 3, a layer with a current density of 0.01 mA / cm at 10 V can be regarded as a hole-blocking layer. 2 The following layer can be regarded as a hole-blocking layer.

[0116] Figure 20 shows an example of measurement using such a device. Figure 20 shows the results of devices with films of N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), 1-(2',7'-di-tert-butyl-9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2',7'tBu-2hppSF), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), mPPhen2P:PCBBiF (1:1, weight ratio), mPPhen2P:βNCCP (1:1, weight ratio), and mPPhen2P:2',7'tBu-2hppSF (1:1, weight ratio) formed as layer 3 of the above-mentioned single-hole device for measurement.

[0117] As shown in this figure, it can be said that layers formed with PCBBiF, βNCCP, mPPhen2P, mPPhen2P:PCBBiF (1:1, weight ratio), and mPPhen2P:βNCCP (1:1, weight ratio) are non-hole-blocking layers, and layers formed with mPPhen2P:2',7'tBu-hppSF (1:1, weight ratio) and layers formed with 2',7'tBu-2hppSF are hole-blocking layers.

[0118] In addition, when the layer to be measured is a mixed layer of material A and material B, a device (device X) with the mixed layer set as the measurement object layer of the above-mentioned single-hole device and a device (device Y) with a single layer of the material with a deeper HOMO energy level among material A and material B set as the measurement object layer are manufactured. When the voltage of device X migrates by 1 V or more at a high voltage of 1 mA / cm 2 at this time, this layer can be regarded as a hole-blocking layer.

[0119] The DLL preferably contains an organic compound with a strong basicity and an acid dissociation constant pKa of 8 or more. By containing an organic compound with a strong basicity and an acid dissociation constant pKa of 8 or more, the DLL can block holes and accumulate holes at the interface on the electron transport layer side. Note that the organic compound with a strong basicity and an acid dissociation constant pKa of 8 or more is preferably pKa 10 or more, and more preferably pKa 12 or more. In addition, in order to reduce the probability of recombination with electrons in the DLL, the organic compound with a strong basicity and an acid dissociation constant pKa of 8 or more preferably does not have an electron transport skeleton. Note that 2hppSF is an organic compound with a strong basicity and an acid dissociation constant of 13.95.

[0120] The fact that an organic compound with a strong basicity and a large acid dissociation constant pKa blocks holes stems from the fact that a material with a large pKa has a large dipole moment. Through the interaction between this dipole moment and holes, the DLL containing a material with a large acid dissociation constant pKa can block holes.

[0121] In addition, a material with a large acid dissociation constant pKa has high nucleophilicity, which is also one of the reasons for blocking holes. A material with high nucleophilicity sometimes reacts with a molecule that accepts a hole and becomes a cation radical to generate a new molecule or an intermediate state. By this reaction, holes are consumed, and sometimes the hole transport property of the DLL is greatly reduced.

[0122] Note that the above-mentioned organic compound with a strong basicity and an acid dissociation constant pKa of 8 or more is an organic compound with a basic skeleton, and preferably an organic compound with an acid dissociation constant pKa of 10 or more for this basic skeleton. In addition, more preferably, it is an organic compound with an acid dissociation constant pKa of 12 or more for this basic skeleton.

[0123] In addition, as the acid dissociation constant pKa of the basic skeleton, the value of an organic compound in which a part of the skeleton is replaced by hydrogen can be used. In addition, as an index of the acidity of an organic compound with a basic skeleton, the acid dissociation constant pKa of this basic skeleton can be used. In addition, for an organic compound with multiple basic skeletons, the acid dissociation constant pKa of the basic skeleton with the highest acid dissociation constant pKa can be used as an index of the acidity of this organic compound. The acid dissociation constant pKa is preferably the value measured using water as a solvent.

[0124] Alternatively, the acid dissociation constant pKa of an organic compound can also be obtained by the following calculation.

[0125] First, the initial structure of the molecular structure of each molecule that becomes the calculation model is the most stable structure (singlet ground state) obtained by first-principles calculation.

[0126] For the above first-principles calculations, the most stable structure in the singlet ground state was calculated using Jaguar, a quantum chemistry calculation software manufactured by Schrodinger, Inc., through density functional theory (DFT). The 6-31G** basis function was used, and the B3LYP-D3 functional was used. As the structure for quantum chemistry calculations, the Maestro GUI manufactured by Schrodinger, Inc. was used, and conformational analysis was performed using Mixed torsional / Low-mode sampling for sampling.

[0127] In the pKa calculation, one or more atoms of each molecule were specified as basic positions. To explore the stable structure of the protonated molecule in water, Macro Model was used. Conformational search was performed using the OPLS2005 force field, and the lowest energy conformer was used. Then, the structure was optimized using the pKa calculation module of Jaguar with B3LYP / 6-31G*, followed by a single-point calculation using cc-pVTZ(+). The pKa value was calculated using an empirical correction for the functional group. For the molecule with one or more atoms specified as basic positions, the maximum value among the obtained results was used as the pKa value.

[0128] Organic compounds with a high acid dissociation constant pKa are preferably organic compounds having a pyrrolidine skeleton, a piperidine skeleton, or a hexahydropyrimido[4,5-d]pyrimidine skeleton. In addition, the above organic compounds are preferably organic compounds having a guanidine skeleton. Specifically, as examples, organic compounds having a basic skeleton represented by the following structural formulas (120) to (123) can be cited.

[0129] [Chemical formula 1]

[0130]

[0131] In addition, preferably, the organic compound having an acid dissociation constant pKa of 8 or more is specifically an organic compound having a bicyclic structure in which the atoms constituting the ring have two or more nitrogens, a heteroaromatic ring having 2 to 30 carbon atoms constituting the ring, or an aromatic ring having 6 to 30 carbon atoms constituting the ring. More specifically, it is an organic compound having a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton, a heteroaromatic ring having 2 to 30 carbon atoms constituting the ring, or an aromatic ring having 6 to 30 carbon atoms constituting the ring. More preferably, the above-mentioned organic compound is an organic compound having a bicyclic structure in which the atoms constituting the ring have two or more nitrogens and a heteroaromatic ring having 2 to 30 carbon atoms constituting the ring. More specifically, it is an organic compound having a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton and a heteroaromatic ring having 2 to 30 carbon atoms constituting the ring.

[0132] In addition, preferably, more specifically, it is an organic compound represented by the following general formula (G1).

[0133] [Chemical formula 2]

[0134]

[0135] Note that in the organic compound represented by the above general formula (G1), X is a group represented by the following general formula (G1-1), and Y is a group represented by the following general formula (G1-2). In addition, R 1 and R 2 each independently represent hydrogen or deuterium, h represents an integer from 1 to 6, and Ar represents a substituted or unsubstituted heteroaromatic ring having 2 to 30 carbon atoms constituting the ring or an aromatic ring having 6 to 30 carbon atoms constituting the ring. In addition, Ar is preferably a substituted or unsubstituted heteroaromatic ring having 2 to 30 carbon atoms constituting the ring.

[0136] [Chemical formula 3]

[0137]

[0138] Note that in the above general formulas (G1-1) and (G1-2), R 3 to R 6 each independently represent hydrogen or deuterium, m represents an integer from 0 to 4, n represents an integer from 1 to 5, and m + 1 ≥ n (m + 1 is greater than or equal to n). When m or n is 2 or more, the plurality of R 3 to R 6 may be the same as or different from each other.

[0139] In addition, the organic compound represented by the above general formula (G1) is preferably any one of the following general formulas (G2-1) to (G2-6).

[0140] [Chemical Formula 4]

[0141]

[0142] Note that R 11 to R 26 each independently represents hydrogen or deuterium, h represents an integer from 1 to 6, Ar represents a substituted or unsubstituted heteroaromatic ring having 2 to 30 carbon atoms forming the ring or a substituted or unsubstituted aromatic ring having 6 to 30 carbon atoms forming the ring. In addition, Ar is preferably a substituted or unsubstituted heteroaromatic ring having 2 to 30 carbon atoms forming the ring.

[0143] In addition, in the above general formulas (G1) and (G2-1) to (G2-6), as the substituted or unsubstituted heteroaromatic ring having 2 to 30 carbon atoms forming the ring or the aromatic ring having 6 to 30 carbon atoms forming the ring represented by Ar, specifically, a pyridine ring, a bipyridine ring, a pyrimidine ring, a bipyrimidine ring, a pyrazine ring, a bipyrazine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a benzoquinoline ring, a phenanthroline ring, a quinoxaline ring, a benzoquinoxaline ring, a dibenzoquinoxaline ring, an azofluorene ring, a diazofluorene ring, a carbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, a dibenzofuran ring, a benzonaphthofuran ring, a dinaphthofuran ring, a dibenzothiophene ring, a benzonaphthothiophene ring, a dinaphthothiophene ring, a benzofuranopyridine ring, a benzofuranopyrimidine ring, a benzothiophenopyridine ring, a benzothiophenopyrimidine ring, a naphthofuranopyridine ring, a naphthofuranopyrimidine ring, a naphthothiophenopyridine ring, a naphthothiophenopyrimidine ring, an acridine ring, an xanthene ring, a phenothiazine ring, a phenoxazine ring, a phenazine ring, a triazole ring, an oxazole ring, an oxadiazole ring, a thiazole ring, a thiadiazole ring, an imidazole ring, a benzimidazole ring, a pyrazole ring or a pyrrole ring, etc. can be cited. In addition, in the above general formulas (G1) and (G2-1) to (G2-6), as the substituted or unsubstituted heteroaromatic ring having 6 to 30 carbon atoms forming the ring represented by Ar, specifically, a benzene ring, a naphthalene ring, a fluorene ring, a dimethylfluorene ring, a diphenylfluorene ring, a spirofluorene ring, an anthracene ring, a phenanthrene ring, a triphenylene ring, a pyrene ring, a tetracene ring, (chrysene) ring, a benzo[a]anthracene ring, etc. can be cited. In addition, it is particularly preferably any one of the following structural formulas (Ar-1) to (Ar-27).

[0144] [Chemical Formula 5]

[0145]

[0146] Note that the above Ar contains nitrogen as an atom forming the ring, and this Ar is preferably bonded to the skeleton represented in the parentheses in the general formula (G1) by a bond of the nitrogen or the carbon adjacent to the nitrogen.

[0147] As the organometallic compounds represented by the above general formula (G1) and the above general formulas (G2-1) to (G2-6), specifically, for example, 1,1'-(9,9'-spirobi[9H-fluorene]-2,7-diyl)bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: 2,7hpp2SF) (structural formula 108), 1-(9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2hppSF) (structural formula 109), etc., which are organic compounds represented by the following structural formulas (101) to (117). In addition, among them, an organic compound having a spirofluorene skeleton as shown in structural formulas (106) to (109) or an organic compound having one hexahydropyrimidopyrimidine skeleton as shown in structural formulas (102), structural formula (104), structural formula (105), structural formula (109), structural formula (110), and structural formula (115) is preferred, and an organic compound represented by structural formula (109) is particularly preferred.

[0148] [Chemical formula 6]

[0149]

[0150] Different from alkali metals, alkaline earth metals, or their compounds, such organic compounds have the following advantages in addition to being stable: less concern about metal contamination in the production line; easy evaporation coating; etc. Therefore, they are more suitable for light-emitting devices manufactured by a photolithography process. Of course, they are also suitable for light-emitting devices manufactured by a process that does not use photolithography.

[0151] Furthermore, from the viewpoint of suppressing the recombination of injected electrons and blocked holes on an organic compound having a strong basicity with pKa of 8 or more, an organic compound having a strong basicity with pKa of 8 or more preferably does not contain an electron-transporting skeleton. Specifically, as the organic compound having a strong basicity with pKa of 8 or more, 1-(9,9'-spirobi[9H-fluorene]-2-yl)-1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine (abbreviation: 2hppSF), 2,9-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidin-1-yl)-1,10-phenanthroline (abbreviation: 2,9hpp2Phen), 4,7-di-1-pyrrolidinyl-1,10-phenanthroline (abbreviation: Pyrrd-Phen), or 8,8'-pyridine-2,6-diyl-bis(5,6,7,8-tetrahydroimidazo[1,2-a]pyrimidine) (abbreviation: 2,6tip2Py) and other organic compounds can be used.

[0152] In addition, the DLL preferably contains a material having electron transporting properties in addition to an organic compound having a strong basicity with a pKa of 8 or higher. As the material having electron transporting properties, for example, bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-hydroxyquinolinato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-hydroxyquinolinato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ) and other metal complexes, and organic compounds including π-deficient heteroaromatic rings are preferably used. As the organic compound including a π-deficient heteroaromatic skeleton, for example, an organic compound including a heteroaromatic ring having a triazole skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, an organic compound including a heteroaromatic ring having a diazine skeleton, and an organic compound including a heteroaromatic ring having a triazine skeleton can be cited.

[0153] Among them, an organic compound including a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), an organic compound including a heteroaromatic ring having a pyridine skeleton, or an organic compound including a heteroaromatic ring having a triazine skeleton has good reliability, and thus is preferred. In particular, an organic compound including a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound including a heteroaromatic ring having a triazine skeleton have high electron transporting properties and contribute to reducing the driving voltage. In addition, a benzofuranopyrimidine skeleton, a benzothiophenopyrimidine skeleton, a benzofuranopyrazine skeleton, and a benzothiophenopyrazine skeleton have high reliability, and thus are preferred.

[0154] As the organic compound having a π-deficient heteroaromatic skeleton, the materials exemplified as the organic compound having electron transporting properties in the above electron transporting layer can be used. In particular, an organic compound including a heteroaromatic ring having a diazine skeleton, an organic compound including a heteroaromatic ring having a pyridine skeleton, or an organic compound including a heteroaromatic ring having a triazine skeleton has good reliability, and thus is preferred. In particular, an organic compound including a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound including a heteroaromatic ring having a triazine skeleton have high electron transporting properties and contribute to reducing the driving voltage. Among them, organic compounds having a phenanthroline skeleton such as mTpPPhen, PnNPhen, and mPPhen2P are preferably used, and an organic compound having a phenanthroline dimer structure such as mPPhen2P is more preferably used because it has good stability. In addition, since the pKa of a material having a pyridine skeleton or a phenanthroline skeleton is high and the hole blocking property becomes high, it is particularly preferred to use it as the electron transporting material of the DLL of the light emitting device according to one embodiment of the present invention.

[0155] In addition, the LUMO energy level of the electron-transporting material in the DLL is preferably -3.00 eV or higher and -2.00 eV or lower because the electron injection barrier into the light-emitting layer is reduced.

[0156] Note that the thickness of the DLL is preferably thin. However, since the driving voltage increases when it is too thick and the characteristics, especially the reliability, deteriorate when it is too thin, its thickness is preferably 2 nm or more and 13 nm or less, more preferably 5 nm or more and 10 nm or less.

[0157] In addition, the organic compound with strong basicity in the DLL preferably does not have electron-donating properties. Additionally, the organic compound with strong basicity preferably does not have electron-donating properties to the electron-transporting organic compound. When the organic compound with strong basicity has electron-donating properties, it easily reacts with atmospheric components such as water and oxygen, so the stability is poor. By including the organic compound with strong basicity and the electron-transporting organic compound, the hole-transporting property of the DLL can be significantly reduced. Therefore, the organic compound with strong basicity can not have electron-donating properties. Thus, a light-emitting device stable to atmospheric components such as water and oxygen can be manufactured. In addition, in the DLL, the signal observed by electron spin resonance method (ESR: Electron Spin Resonance) is preferably small or no signal is observed. For example, the spin density due to the signal observed around the g value of 2.00 is preferably 1×10 17 spins / cm 3 Hereinafter, it is more preferably less than 1×10 16 spins / cm 3 .

[0158] In addition, CGL1 is preferably formed using a composite material containing a substance with electron-accepting properties and a hole-transporting organic compound or a laminate of a substance with electron-accepting properties and a hole-transporting organic compound, and particularly preferably formed using a composite material containing a hole-transporting organic compound. In addition, when CGL1 has a laminate structure, it is preferable to provide a layer of a substance with electron-accepting properties on the DDL side and a layer of a hole-transporting organic compound on the cathode side.

[0159] In addition, the substance with electron-accepting properties in CGL1 preferably has electron-accepting ability. Additionally, the substance with electron-accepting properties preferably has electron-accepting ability to the hole-transporting organic compound. By the substance with electron-accepting properties having electron-accepting ability, charge separation occurs in CGL1 and electrons can be injected into the DLL. In addition, CGL1 preferably observes signals by electron spin resonance method. For example, the spin density due to the signal observed around the g value of 2.00 is preferably 1×10 17 spins / cm 3Above, more preferably 1×10 18 spins / cm 3 Above, even more preferably 1×10 19 spins / cm 3 Above.

[0160] As the substance having an acceptor property, an organic compound having an electron-withdrawing group (halogen group, cyano group) can be used, and examples thereof include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloroquinone, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene) malononitrile, etc. In particular, compounds such as HAT-CN in which an electron-withdrawing group is bonded to a fused aromatic ring having a plurality of heteroatoms are thermally stable, and thus are preferred. In addition, [3]axylene derivatives including an electron-withdrawing group (especially a halogen group such as a fluorine group, a cyano group) have a very high electron-accepting property and are thus preferred. Specifically, examples thereof include: α,α',α''-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzyl cyanide], α,α',α''-1,2,3-cyclopropanetriyl tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzyl cyanide], α,α',α''-1,2,3-cyclopropanetriyl tris[2,3,4,5,6-pentafluorobenzyl cyanide], etc. As the substance having an acceptor property, in addition to the above organic compounds, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can also be used.

[0161] As the organic compound having a hole-transporting property for the composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and high molecular compounds (oligomers, dendrimers, polymers, etc.) can be used. As the organic compound having a hole-transporting property for the composite material, it is preferable to use an organic compound having a hole mobility of 1×10 -6 cm 2An organic compound of not less than / Vs. The organic compound having hole transporting properties for use in a composite material is preferably a compound containing a fused aromatic ring or a π - electron - rich heteroaromatic ring. As the fused aromatic ring, an anthracene ring, a naphthalene ring, etc. are preferred. Further, as the π - electron - rich heteroaromatic ring, a fused aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton is preferred, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which these rings are further fused with an aromatic ring or a heteroaromatic ring is preferred.

[0162] This organic compound having hole transporting properties preferably has any of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, it may be an aromatic amine having a substituent including a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine including a naphthalene ring, or an aromatic monoamine in which 9 - fluorenyl is bonded to the nitrogen of the amine through an arylene group. Note that when these organic compounds having hole transporting properties are substances including N,N - bis(4 - biphenyl)amino, a light - emitting device with a long lifespan can be manufactured, so they are preferred.

[0163] As the above-mentioned organic compound having hole transporting properties, specifically, N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophene-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthalen-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthalen-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthalen-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthalen-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthalen-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthalen-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthalen-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'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-Phenyl-9H-carbazol-9-yl)phenyl]tris(biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-Phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-Bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-Bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(Biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(Biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-Phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-Phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-Phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-Phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-Diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-Naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-Di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-Phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(Biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), N,N-Bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi-9H-fluorene-4-amine, N,N-Bis(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-Spirobi-9H-fluorene-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, etc.

[0164] In addition, as an organic compound having hole transport properties, as other aromatic amine compounds, N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), etc. can also be used.

[0165] In addition, it is preferable to provide an electron relay layer between CGL1 and DLL. The electron relay layer has at least electron transport properties and has a function of preventing the interaction between CGL1 and DLL and smoothly transferring electrons. The LUMO energy level of the electron-transporting substance contained in the electron relay layer is preferably located between the LUMO energy level of the acceptor substance in CGL1 and the LUMO energy level of the electron-transporting substance contained in DLL. Specifically, the LUMO energy level of the electron-transporting substance in the electron relay layer is -5.00 eV or more, preferably -5.00 eV or more and -3.00 eV or less, more preferably -4.30 eV or more and -3.00 eV or less, and further preferably -4.30 eV or more and -3.30 eV or less. Thus, it is easy to inject electrons generated in CGL1 into DLL, and the rise of the driving voltage can be suppressed. In addition, as the electron-transporting substance in the electron relay layer, a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand is preferably used.

[0166] Specifically, it is possible to use perylene tetracarboxylic acid derivatives such as diquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA), 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine (abbreviation: HATNA-F6), 3,4,9,10-perylenetetracarboxylic diimide (abbreviation: PTCDI), 3,4,9,10-perylenetetracarboxylic acid-bis-benzimidazole (abbreviation: PTCBI), (C60-Ih)[5,6]fullerene (abbreviation: C60), (C70-D5h)[5,6]fullerene (abbreviation: C70), phthalocyanine (abbreviation: H2Pc). In addition, it is possible to use metal phthalocyanines and their derivatives containing copper, zinc, cobalt, iron, chromium, nickel, etc., such as copper phthalocyanine (abbreviation: CuPc), zinc phthalocyanine (abbreviation: ZnPc), cobalt phthalocyanine (abbreviation: CoPc), iron phthalocyanine (abbreviation: FePc), tin phthalocyanine (abbreviation: SnPc), tin oxide phthalocyanine (abbreviation: SnOPc), titanium oxide phthalocyanine (abbreviation: TiOPc), vanadium oxide phthalocyanine (abbreviation: VOPc). In particular, it is preferable to use phthalocyanine metal complexes such as copper phthalocyanine or zinc phthalocyanine, or 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2',3'-c]phenazine.

[0167] In addition, the thickness of the electron relay layer is preferably 1 nm or more and 10 nm or less, more preferably 2 nm or more and 5 nm or less.

[0168] The light-emitting device according to one embodiment of the present invention having the above structure can be a light-emitting device with high current efficiency and suppression of the rise in driving voltage.

[0169] Although the light-emitting device according to one embodiment of the present invention is particularly preferably used as a light-emitting device through a photolithography process, the light-emitting device not manufactured through a photolithography process also has high stability to the atmosphere, thus improving the yield, and does not require strict atmosphere management in the manufacturing process, thus contributing to cost reduction.

[0170] (Embodiment 2)

[0171] In the present embodiment, a light-emitting device according to one embodiment of the present invention will be described in detail.

[0172] Figure 2A and Figure 2B is a schematic diagram of a light-emitting device according to one embodiment of the present invention. In Figure 2AIn the light-emitting device shown, a first electrode 101 is provided on an insulator 100, and an organic compound layer 103 is included between the first electrode 101 and the second electrode 102. The organic compound layer 103 includes at least a light-emitting layer 113, an electron transport layer 114, a first layer 119 (DLL in Embodiment 1), and a second layer 117 (CGL1 in Embodiment 1). Additionally, a hole injection layer 111 and a hole transport layer 112 are preferably included. The light-emitting layer 113 is a layer containing a light-emitting substance and emits light when a voltage is applied between the first electrode 101 and the second electrode 102.

[0173] In addition to the above layers, the organic compound layer 103 may further include functional layers such as an electron blocking layer, an exciton blocking layer, etc. Conversely, any of the above layers may not be provided.

[0174] The first layer 119 is a layer containing an organic compound having strong basicity as described in Embodiment 1. The first layer 119 may further contain an organic compound having electron transport properties. In addition, the second layer 117 is a layer that generates charges by applying a voltage. The second layer 117 is preferably a layer containing an organic compound having hole transport properties and a substance having an acceptor property for the organic compound. Additionally, a third layer may be included between the first layer 119 and the second layer 117. The third layer is a layer provided to facilitate electron injection between the first layer 119 and the second layer 117.

[0175] Regarding the specific structures of the first layer 119, the second layer 117, and the third layer, they are described in detail as the structures of DLL, CGL1, and the electron relay layer in Embodiment 1, so repeated descriptions are omitted here.

[0176] Note that although in the example shown in this embodiment, the first electrode 101 is an electrode including an anode, the second electrode 102 is an electrode including 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, that is, a so-called reverse stack structure, may also be adopted. Figure 2B The shown light-emitting device has the above reverse stack structure. Figure 2B The shown light-emitting device has a stacked structure in which a second electrode 102, a second layer 117, a first layer 119, an electron transport layer 114, a light-emitting layer 113, a hole transport layer 112, a hole injection layer 111, and a first electrode 101 are sequentially stacked from one side of the insulator 100. When using a light-emitting device having this reverse stack structure, the relatively stable hole injection layer 111 becomes the surface, thereby enabling a more reliable light-emitting device.

[0177] In addition, the first electrode 101 and the second electrode 102 are formed into a single-layer structure or a stacked structure. When having a stacked structure, the layer in contact with the organic compound layer 103 is used as an anode or a cathode. When the electrode has a stacked structure, there is no work function limitation for the layers other than the layer in contact with the organic compound layer 103, and materials can be selected according to the required characteristics such as resistance value, processing convenience, reflectivity, light transmittance, and stability.

[0178] As the anode, it is preferably formed of a metal, an alloy, a conductive compound, and a mixture thereof having a large work function (specifically, 4.0 eV or more). Specifically, for example, indium tin oxide (ITO), indium tin silicon oxide (ITSO) containing silicon or silicon oxide, indium zinc oxide, indium oxide containing tungsten oxide and zinc oxide (IWZO), etc. can be cited. Although these conductive metal oxide films are usually formed by sputtering, sol-gel methods or the like can also be applied for formation. As an example of the formation method, a method of depositing indium zinc oxide by sputtering using a target in which 1 wt% to 20 wt% of zinc oxide is added to indium oxide can be cited. In addition, indium oxide containing tungsten oxide and zinc oxide (IWZO) can be formed by sputtering using a target in which 0.5 wt% to 5 wt% of tungsten oxide and 0.1 wt% to 1 wt% of zinc oxide are added to indium oxide. In addition, as materials for the anode, 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 metal materials (for example, titanium nitride) can be cited. In addition, a layer formed by laminating them can also be used as the anode. For example, a film in which Al, Ti, and ITSO are sequentially laminated on Ti has high efficiency due to good reflectivity and can achieve a high resolution of several thousand ppi, and thus is preferred. Alternatively, graphene can also be used as a material for the anode. In addition, by using the composite material that can form the hole injection layer 111 described later as the layer in contact with the anode (typically the hole injection layer), the electrode material can be selected regardless of the work function.

[0179] The hole injection layer 111 is in contact with the anode and has the function of facilitating the injection of holes into the organic compound layer 103. Phthalocyanine compounds such as phthalocyanine (abbreviation: H2Pc), phthalocyanine complex compounds such as copper phthalocyanine (CuPc), etc. can be used; aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), etc.; or polymers such as poly(3,4-ethylenedioxythiophene) / (polystyrenesulfonic acid) (abbreviation: PEDOT / PSS) can be used to form the hole injection layer 111.

[0180] In addition, the hole injection layer 111 can also be composed of a substance with electron-accepting properties. As the substance with accepting properties, organic compounds having an electron-withdrawing group (halogen group, cyano group) can be used, and examples include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malononitrile, etc. In particular, compounds such as HAT-CN in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms are thermally stable, so they are preferred. In addition, [3]axylene derivatives including an electron-withdrawing group (especially a halogen group such as a fluorine group, cyano group) have very high electron-accepting properties, so they are preferred. Specifically, examples include: α,α',α”-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α',α”-1,2,3-cyclopropanetriyl tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α',α”-1,2,3-cyclopropanetriyl tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], etc. As the substance with accepting properties, in addition to the above organic compounds, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, etc. can also be used.

[0181] In addition, the hole injection layer 111 is preferably formed using a composite material containing the above-mentioned substance with accepting properties and an organic compound with hole-transporting properties.

[0182] As the organic compound having hole transport property for the composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. As the organic compound having hole transport property for the composite material, it is preferable to use an organic compound having a hole mobility of 1×10 -6 cm 2 / Vs or more. The organic compound having hole transport property for the composite material is preferably a compound containing a fused aromatic hydrocarbon ring or a π-electron-rich heteroaromatic ring. As the fused aromatic hydrocarbon ring, anthracene ring, naphthalene ring, etc. are preferable. In addition, as the π-electron-rich heteroaromatic ring, a fused aromatic ring containing at least one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton is preferable, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which these rings are further fused with an aromatic ring or a heteroaromatic ring is preferable.

[0183] This organic compound having hole transport property preferably has any one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, it can be an aromatic amine having a substituent including a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine including a naphthalene ring, or an aromatic monoamine in which 9-fluorenyl is bonded to the nitrogen of the amine through an arylene group. Note that when these organic compounds having hole transport property are substances including N,N-bis(4-biphenyl)amino, a light-emitting device with a long lifespan can be manufactured, so they are preferable.

[0184] As the above-mentioned organic compound having hole-transporting properties, specifically, N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthalen-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthalen-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthalen-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthalen-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthalen-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthalen-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthalen-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'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBBiF), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-Spirobi-9H-fluorene-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, etc.

[0185] In addition, as an organic compound having hole-transporting properties, as other aromatic amine compounds, N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), etc. can also be used.

[0186] By forming the hole injection layer 111, the hole injection property can be improved, and thus a light-emitting device with a lower driving voltage can be obtained.

[0187] In addition, an organic compound having acceptor properties among substances having acceptor properties can be easily formed by evaporation deposition, so it is a material that is easy to use.

[0188] The hole transport layer 112 is formed to contain an organic compound having hole-transporting properties. The organic compound having hole-transporting properties preferably has a hole mobility of 1×10 -6 cm 2 / Vs or more.

[0189] Examples of the organic compound having hole transporting properties described above include: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), and other compounds having an aromatic amine skeleton;1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-bi(9H-carbazole) (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: 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, 9-(2-naphthyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylene-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]phenanthrene (abbreviation: PCPPn) and other compounds with a carbazole skeleton;Compounds with a thiophene skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV); and compounds with a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II). Among them, compounds with an aromatic amine skeleton or a carbazole skeleton have good reliability and high hole transportability and help to reduce the driving voltage, so they are preferred. Note that substances cited as hole-transporting organic compounds used as composite materials for the hole injection layer 111 can also be appropriately used as materials for the hole transport layer 112.;

[0190] The light-emitting layer 113 is a layer containing a light-emitting substance, preferably containing a light-emitting substance and a host material. Note that the light-emitting layer may also contain other materials. In addition, it may also be a laminate of two layers with different compositions.

[0191] The light-emitting substance can be a fluorescent light-emitting substance, a phosphorescent light-emitting substance, a substance showing thermally activated delayed fluorescence (TADF), or other light-emitting substances.

[0192] In the light-emitting layer, as materials that can be used as fluorescent light-emitting substances, for example, the following substances can be cited. Note that in addition to this, other fluorescent light-emitting substances can also be used.

[0193] Examples include 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenyldiphenyl-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butyldiphenylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyl-di-4,1-phenylene)bis(N,N',N'-triphenylbenzene-1,4-diamine) (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenylbenzene-1,4-diamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N''' - octaphenyldibenzo[g,p] -2,7,10,15 - tetraamine (abbreviation: DBC1), Coumarin 30, N-(9,10 - diphenyl - 2 - anthryl)-N,9 - diphenyl - 9H - carbazol - 3 - amine (abbreviation: 2PCAPA), N-[9,10 - bis(biphenyl - 2 - yl)-2 - anthryl]-N,9 - diphenyl - 9H - carbazol - 3 - amine (abbreviation: 2PCABPhA), N-(9,10 - diphenyl - 2 - anthryl)-N,N’,N’ - triphenyl - 1,4 - phenylenediamine (abbreviation: 2DPAPA), N-[9,10 - bis(biphenyl - 2 - yl)-2 - anthryl]-N,N’,N’ - triphenyl - 1,4 - phenylenediamine (abbreviation: 2DPABPhA), 9,10 - bis(biphenyl - 2 - yl)-N-[4-(9H - carbazol - 9 - yl)phenyl]-N - phenylanthracen - 2 - amine (abbreviation: 2YGABPhA), N,N,9 - triphenylanthracen - 9 - amine (abbreviation: DPhAPhA), Coumarin 545T, N,N’ - diphenylquinacridone (abbreviation: DPQd), Rubrene, 5,12 - bis(biphenyl - 4 - yl)-6,11 - diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]vinyl}-6 - methyl - 4H - pyran - 4 - ylidene)propanedinitrile (abbreviation: DCM1), 2-{2 - methyl - 6-[2-(2,3,6,7 - tetrahydro - 1H,5H - benzo[ij]quinolizin - 9 - yl)vinyl]-4H - pyran - 4 - ylidene}propanedinitrile (abbreviation: DCM2), N,N,N’,N’ - tetra(4 - methylphenyl)tetracene - 5,11 - diamine (abbreviation: p - mPhTD), 7,14 - diphenyl - N,N,N’,N’ - tetra(4 - methylphenyl)acenaphtho[1,2 - a]fluoranthene - 3,10 - diamine (abbreviation: p - mPhAFD), 2-{2 - isopropyl - 6-[2-(1,1,7,7 - tetramethyl - 2,3,6,7 - tetrahydro - 1H,5H - benzo[ij]quinolizin - 9 - yl)vinyl]-4H - pyran - 4 - ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2 - tert - butyl - 6-[2-(1,1,7,7 - tetramethyl - 2,3,6,7 - tetrahydro - 1H,5H - benzo[ij]quinolizin - 9 - yl)vinyl]-4H - pyran - 4 - ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6 - bis{2-[4-(dimethylamino)phenyl]vinyl}-4H - pyran - 4 - ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6 - bis[2-(8 - methoxy - 1,1,7,7 - tetramethyl - 2,3,6,7 - tetrahydro - 1H,5H - benzo[ij]quinolizin - 9 - yl)vinyl]-4H - pyran - 4 - ylidene}propanedinitrile (abbreviation: BisDCJTM), 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-carbazol-2-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), etc. In particular, fused aromatic diamine compounds represented by pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 have high hole trapping properties, high luminous efficiency, and high reliability, so they are preferred.,

[0194] In addition, 5,9-diphenyl-5,9-diaza-13b-borataanthra[3,2,1-de]anthracene (abbreviation: DABNA1), 9-(biphenyl-3-yl)-N,N,5,11-tetraphenyl-5,9-dihydro-5,9-diaza-13b-borataanthra[3,2,1-de]anthracen-3-amine (abbreviation: DABNA2), 2,12-di(tert-butyl)-5,9-bis(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazaborolo[2,3,4-kl]phenazaborole-7-amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetrakis(4-tert-butylphenyl)-5H,9H-[1,4]benzazaborolo[2,3,4-kl]phenazaborole-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-5,9-bis(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzazaborolo[2,3,4-kl]phenazaborole (abbreviation: Me-tBu4DABNA), N 7 , N 7 , N 13 , N 13 , 5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzazaborolo[2,3,4-kl][1,4]benzazaborolo[4',3',2':4,5][1,4]benzazaborolo[3,2-b]phenazaborole-7,13-diamine (abbreviation: ν-DABNA), 2-(4-tert-butylphenyl)benzo[5,6]indolo[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc), etc. nitrogen- and boron-containing fused heteroaromatic compounds, especially compounds having a diaza-borataanthracene skeleton have a narrow emission spectrum and can obtain blue light emission with good color purity, so they can be appropriately used.,

[0195] In addition, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazol-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3’,2’,1’:8,1][1,4]benzazaborolo[2,3,4-kl]phenazaborole (abbreviation: BBCz-G), 9,11-bis[3,6-bis(1,1-dimethylethyl)-9H-carbazol-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3’,2’,1’:8,1][1,4]benzazaborolo[2,3,4-kl]phenazaborole (abbreviation: BBCz-Y), etc. can also be appropriately used.

[0196] When a phosphorescent light-emitting substance is used as a light-emitting substance in the light-emitting layer, examples of materials that can be used include the following substances.

[0197] Examples include: tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp)3]), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazole)iridium(III) (abbreviation: [Ir(Mptz)3]) and other organometallic iridium complexes having a 4H-triazole skeleton; tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazole]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazole)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]) and other organometallic iridium complexes having a 1H-triazole skeleton; fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim)3]), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me)3]), tris(2-[1-{2,6-bis(1-methylethyl)phenyl}-1H-imidazol-2-yl-κN3]-4-cyanophenyl-κC) (abbreviation: CNImIr) and other organometallic iridium complexes having an imidazole skeleton; tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC2)phenyl-κC]iridium(III) (abbreviation: [Ir(cb)3]) and other organometallic complexes having a benzimidazolylidene skeleton; and bis[2-(4’,6’-difluorophenyl)pyridinato-N,C 2’Iridium(III) tetra(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’ iridium(III) acetylacetonate (abbreviation: FIracac), etc., which are organometallic iridium complexes with phenylpyridine derivatives having electron-withdrawing groups as ligands. The above substances are compounds that emit blue phosphorescence and are compounds having a luminescence peak in the wavelength region of 450 nm to 520 nm.

[0198] In addition, examples include: tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-tert-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornanyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: Ir(mpmppm)2(acac)), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]), etc., which are organometallic iridium complexes having a pyrimidine skeleton; (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), etc., which are organometallic iridium complexes having a pyrazine skeleton; tris(2-phenylpyridinato-N,C 2’ )iridium(III) (abbreviation: [Ir(ppy)3]), bis(2-phenylpyridinato-N,C 2’) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy)2(acac)]), bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq)2(acac)]), tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq)3]), tris(2-phenylquinolinato-N,C 2’ ) iridium(III) (abbreviation: [Ir(pq)3]), bis(2-phenylquinolinato-N,C 2’ ) iridium(III) acetylacetonate (abbreviation: [Ir(pq)2(acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κ]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy-d3)]), [2-(4-d3-methyl-5-phenyl-2-pyridinyl-κN2)phenyl-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3)2(mdppy-d3)]), [2-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(mbfpypy)]), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium (abbreviation: [Ir(ppy)2(mdppy)]) and other organometallic iridium complexes having a pyridine skeleton; and rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac)3(Phen)]). The above substances are mainly compounds exhibiting green phosphorescence and have a luminescence peak in the wavelength region of 500 nm to 600 nm. In addition, organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because of their particularly excellent reliability or luminescence efficiency.

[0199] In addition, examples include: bis[4,6-bis(3-methylphenyl)pyrimidinato](diisobutyrylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dineopentanoylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), bis[4,6-di(naphthalen-1-yl)pyrimidinato](dineopentanoylmethanato)iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]) and other organometallic iridium complexes having a pyrimidine skeleton; bis(2,3,5-triphenylpyrazinato)(acetylacetonato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(dineopentanoylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), bis[2,3-bis(4-fluorophenyl)quinoxalinato](acetylacetonato)iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]) and other organometallic iridium complexes having a pyrazine skeleton; tris(1-phenylisoquinoline-N,C 2’ )iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinoline-N,C 2’ )iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinolinyl-κN]phenyl-κC]iridium(III), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolinyl-κN]phenyl-κC]iridium(III) and other organometallic iridium complexes having a pyridine skeleton; platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP); and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)3(Phen)]), tris[1-(2-thienoyl)-3,3,3-trifluoroacetone](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]). The above substances are compounds that exhibit red phosphorescence and have a luminescence peak in the wavelength region of 600 nm to 700 nm. In addition, organometallic iridium complexes having a pyrazine skeleton can obtain red luminescence with good chromaticity.

[0200] In addition, in addition to the above phosphorescent compounds, known phosphorescent compounds can also be selected and used.

[0201] As TADF materials, fullerenes and their derivatives, acridine and its derivatives, eosin derivatives, etc. can be used. In addition, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), palladium (Pd), etc. can also be cited. As such metal-containing porphyrins, for example, protoporphyrin-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (SnF2(OEP)), etioporphyrin-tin fluoride complex (SnF2(Etio I)), octaethylporphyrin-platinum chloride complex (PtCl2OEP), etc., represented by the following structural formulas can also be cited.

[0202] [Chemical formula 7]

[0203]

[0204] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridin)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), etc., which have one or both of a π-rich heteroaromatic ring and a π-deficient heteroaromatic ring, can be used. Such a heterocyclic compound has a π-rich heteroaromatic ring and a π-deficient heteroaromatic ring, and has high electron transportability and hole transportability, so it is preferred. Among them, in the skeleton having a π-deficient heteroaromatic ring, a pyridine skeleton, a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and a triazine skeleton are stable and have good reliability, so they are preferred. In particular, a benzofuranopyrimidine skeleton, a benzothiophenopyrimidine skeleton, a benzofuranopyrazine skeleton, and a benzothiophenopyrazine skeleton have high acceptor properties and good reliability, so they are preferred. In addition, in the skeleton having a π-rich heteroaromatic ring, an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton are stable and have good reliability, so it is preferred to have at least one of the above skeletons. In addition, a dibenzofuran skeleton is preferably used as the furan skeleton, and a dibenzothiophene skeleton is preferably used as the thiophene skeleton. As the pyrrole skeleton, an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, and a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferably used. In a substance in which a π-rich heteroaromatic ring and a π-deficient heteroaromatic ring are directly bonded, the electron donating property of the π-rich heteroaromatic ring and the electron accepting property of the π-deficient heteroaromatic ring are both high, and the energy difference between the S1 energy level and the T1 energy level becomes small, so thermally activated delayed fluorescence can be obtained efficiently, so it is particularly preferred. Note that an aromatic ring bonded with an electron-withdrawing group such as a cyano group can also be used instead of the π-deficient heteroaromatic ring. In addition, as the π-rich skeleton, an aromatic amine skeleton, a phenazine skeleton, etc. can be used.In addition, as the π-deficient electron skeleton, an oxygen xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane and boranthrene, an aromatic ring, a heteroaromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. can be used. Thus, at least one of the π-deficient electron skeleton and the π-rich electron skeleton can be used instead of the π-deficient electron heteroaromatic ring and the π-rich electron heteroaromatic ring.

[0205] [Chemical formula 8]

[0206]

[0207] The TADF material refers to a material in which the energy difference between the S1 energy level and the T1 energy level is small and has the function of converting triplet excitation energy into singlet excitation energy through reverse intersystem crossing. Therefore, the triplet excitation energy can be up-converted into singlet excitation energy (reverse intersystem crossing) by a small amount of thermal energy and singlet excited states can be efficiently generated. In addition, the triplet excitation energy can be converted into light emission.

[0208] An exciplex formed by two substances in the excited state has the function of a TADF material that can convert triplet excitation energy into singlet excitation energy because the energy difference between the S1 energy level and the T1 energy level is extremely small.

[0209] Note that as an index of the T1 energy level, a phosphorescence spectrum observed at low temperature (for example, 77K to 10K) can be used. For the TADF material, preferably, when the wavelength energy of the extrapolated line obtained by drawing a tangent at the tail on the short wavelength side of the fluorescence spectrum is the S1 energy level and the wavelength energy of the extrapolated line obtained by drawing a tangent at the tail on the short wavelength side of the phosphorescence spectrum is the T1 energy level, the difference between S1 and T1 is 0.3 eV or less, and more preferably 0.2 eV or less.

[0210] In addition, when using the TADF material as the luminescent substance, the S1 energy level of the host material is preferably higher than the S1 energy level of the TADF material. In addition, the T1 energy level of the host material is preferably higher than the T1 energy level of the TADF material.

[0211] As the host material of the light-emitting layer, various carrier transport materials such as an organic compound having electron-transporting properties and / or an organic compound having hole-transporting properties or the above-mentioned TADF material can be used.

[0212] As the organic compound having hole-transporting property, an organic compound having an amine skeleton or a π-electron-rich heteroaromatic ring skeleton is preferably used. As the π-electron-rich heteroaromatic ring, a fused aromatic ring containing at least any one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton is preferred, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which these rings are further fused with an aromatic ring or a heteroaromatic ring is preferred.

[0213] This organic compound having hole-transporting property preferably has any of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, it may be an aromatic amine having a substituent including a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine including a naphthalene ring, or an aromatic monoamine in which 9-fluorenyl is bonded to the nitrogen of the amine through an arylene group. Note that when these organic compounds having hole-transporting property are substances including N,N-bis(4-biphenyl)amino, a light-emitting device having a long lifetime can be manufactured, and thus they are preferred.

[0214] As such organic compounds, for example, the following can be cited: 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-bis(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), etc., compounds having an aromatic amine skeleton; 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-bis(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCP), etc., compounds having a carbazole skeleton; 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), etc., compounds having a thiophene skeleton; and 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), etc., compounds having a furan skeleton. Among them, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton have good reliability and high hole transportability and contribute to reducing the driving voltage, so they are preferred. In addition, organic compounds exemplified as examples of organic compounds having hole transportability as the hole transport layer can also be used.

[0215] As an organic compound having electron transporting properties, for example, it is preferably used: bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-hydroxyquinolinato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-hydroxyquinolinato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ) and other metal complexes, and organic compounds including π-deficient heteroaromatic rings. As an organic compound containing a π-deficient heteroaromatic skeleton, for example, an organic compound containing a heteroaromatic ring having a triazole skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, an organic compound containing a heteroaromatic ring having a diazine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton can be cited.

[0216] Among them, an organic compound containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), an organic compound containing a heteroaromatic ring having a pyridine skeleton, or an organic compound containing a heteroaromatic ring having a triazine skeleton has good reliability, so it is preferred. In particular, an organic compound containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound containing a heteroaromatic ring having a triazine skeleton have high electron transporting properties, which helps to reduce the driving voltage. In addition, a benzofuranopyrimidine skeleton, a benzothiophenopyrimidine skeleton, a benzofuranopyrazine skeleton, and a benzothiophenopyrazine skeleton have high acceptor properties and high reliability, so they are preferred.

[0217] Examples of organic compounds containing a π-electron-deficient heteroaromatic ring skeleton include: 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2"-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[ organic compounds having an azole skeleton, such as 3-(dibenzothiophene-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II), 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviated as BzOs); 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviated as 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviated as TmPyPB), bathophenanthroline (abbreviated as Bphen), bathocuproin (abbreviated as BCP), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviated as NBphen), 2,2'-(1,3-phenylene)bis(9 -phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviation: mTpPPhen), 2-phenyl-9-(2-triphenylene)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-phenanthrenyl)-1-naphthyl]-1,10-phenanthroline (abbreviation: PnNPhen), 2-[4-(2-triphenylene)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen); 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq- II), 2-[3-(3'-dibenzothiophene-4-yl)biphenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2mpPCBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as: 2CzPDBq-Ⅲ), 7-[3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]Quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(Dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3'-(Dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-Bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-Bis[3-(4-dibenzothiophenyl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-Bis[3-(9H-carbazol-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-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-Bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-Bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(Dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-Binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2'-(Pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(Pyridine-2,6-diyl)bis{4-[4-(naphthalen-2-yl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(Biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-Bis(4-naphthalen-1-ylphenyl)-4-[4-(pyridin-3-yl)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'-spirobi[9H-fluorene]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-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 (abbreviation: mFBPTzn), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(dibenzothiophen-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-phenanthryl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenylindolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3'-(triphenylene-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',1”-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviation: mBP-TPDBfTzn) and other organic compounds containing a heteroaromatic ring having a triazine skeleton. Organic compounds containing a heteroaromatic ring having a diazine skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, or an organic compound containing a heteroaromatic ring having a triazine skeleton have good reliability, and thus are preferred. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties, which helps to reduce the driving voltage.

[0218] As the TADF material that can be used as the host material, the same materials as those exemplified above as the TADF material can be used. When the TADF material is used as the host material, the triplet excitation energy generated by the TADF material is converted into singlet excitation energy through reverse intersystem crossing and further energy is transferred to the luminescent material, thereby improving the luminous efficiency of the light-emitting device. At this time, the TADF material is used as the energy donor and the luminescent material is used as the energy acceptor.

[0219] This is very effective when the above-mentioned luminescent material is a fluorescent luminescent material. In addition, at this time, in order to obtain high luminous efficiency, the S1 energy level of the TADF material is preferably higher than the S1 energy level of the fluorescent luminescent material. In addition, 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.

[0220] In addition, it is preferable to use a TADF material that emits light overlapping the wavelength of the absorption band on the lowest energy side of the fluorescent luminescent material. Thus, the excitation energy is smoothly transferred from the TADF material to the fluorescent luminescent material, and high-efficiency light emission can be obtained, so it is preferred.

[0221] In order to efficiently generate singlet excitation energy from triplet excitation energy through reverse intersystem crossing, it is preferred to generate carrier recombination in the TADF material. In addition, it is preferred that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent emitter. For this purpose, the fluorescent emitter preferably has a protecting group around the emitter (the skeleton that causes luminescence) possessed by the fluorescent emitter. As this protecting group, a substituent without a π bond is preferred, and a saturated hydrocarbon is preferred. Specifically, an alkyl group having 3 or more and 10 or less carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 or more and 10 or less carbon atoms, or a trialkylsilyl group having 3 or more and 10 or less carbon atoms can be cited. More preferably, it has a plurality of protecting groups. Since the substituent without a π bond has almost no function of transporting carriers, it has almost no influence on carrier transport or carrier recombination, and can keep the emitter of the TADF material and the fluorescent emitter away from each other. Here, the emitter refers to the atomic group (skeleton) that causes luminescence in the fluorescent emitter. The emitter preferably has a skeleton with a π bond, preferably contains an aromatic ring, and preferably has a fused aromatic ring or a fused heteroaromatic ring. As such an emitter, for example, a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, a naphthobisbenzofuran skeleton, etc. In particular, a fluorescent emitter having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, a naphthobisbenzofuran skeleton has a high fluorescence quantum yield, so it is preferred.

[0222] In the case of using a fluorescent luminescent substance as the luminescent substance, as the host material, a material having an anthracene skeleton is preferably used. By using a substance having an anthracene skeleton as the host material of the fluorescent luminescent substance, a luminescent layer with high luminous efficiency and durability can be achieved. Among the substances having an anthracene skeleton used as the host material, a substance having a diphenylanthracene skeleton (especially 9,10-diphenylanthracene skeleton) is chemically stable, so it is preferred. In addition, when the host material has a carbazole skeleton, the hole injection / transport property is improved, so it is preferred. In the case of including a benzocarbazole skeleton in which a benzene ring is fused to carbazole, its HOMO energy level is about 0.1 eV shallower than that of carbazole, and holes are easily injected, so it is more preferred. In particular, when the host material has a dibenzocarbazole skeleton, its HOMO energy level is about 0.1 eV shallower than that of carbazole, not only are holes easily injected, but also the hole transport property and heat resistance are improved, so it is preferred. Therefore, a substance further preferably used as the host material is a substance having a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton). Note that from the above perspective of hole injection / transport property, a benzofluorene skeleton or a dibenzofluorene skeleton can also be used instead of the carbazole skeleton. Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]-benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-[4-(9-phenyl-9H-fluoren-9-yl)-biphenyl-4'-yl]-anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,β-ADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthryl)-benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthryl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), etc. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties, so they are preferred.

[0223] In addition, the host material may also be a material that mixes multiple substances. When using a mixed host material, it is preferable to mix an organic compound with electron-transporting properties and an organic compound with hole-transporting properties. By mixing an organic compound with electron-transporting properties and an organic compound with hole-transporting properties, it becomes easier to adjust the transport properties of the light-emitting layer 113, and it is also possible to more simply control the recombination region. The weight ratio of the content of the organic compound with hole-transporting properties to the organic compound with electron-transporting properties may be organic compound with hole-transporting properties: organic compound with electron-transporting properties = 1:19 to 19:1.

[0224] Note that, as part of the above-mentioned mixed materials, a phosphorescent light-emitting substance can be used. The phosphorescent light-emitting substance can be used as an energy donor that supplies excitation energy to the fluorescent light-emitting substance when the fluorescent light-emitting substance is used as the light-emitting substance.

[0225] In addition, these mixed materials can also be used to form an exciplex. By selecting a combination of exciplexes that emit light with a wavelength overlapping the absorption band on the lowest energy side of the light-emitting substance, energy transfer can be made smooth, and thus light emission can be obtained efficiently, so it is preferable. In addition, by adopting this structure, the driving voltage can be reduced, so it is preferable.

[0226] Note that at least one of the materials forming the exciplex can be a phosphorescent light-emitting substance. Thereby, triplet excitation energy can be efficiently converted into singlet excitation energy through reverse intersystem crossing.

[0227] Regarding the combination of materials that efficiently form an exciplex, the HOMO energy level of the organic compound with hole-transporting properties is preferably higher than the HOMO energy level of the organic compound with electron-transporting properties. In addition, the LUMO energy level of the organic compound with hole-transporting properties is preferably higher than the LUMO energy level of the organic compound with electron-transporting properties. Note that the LUMO energy level and HOMO energy level of the material can be obtained from the electrochemical characteristics (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV).

[0228] Note that the formation of an exciplex can be confirmed, for example, by comparing the emission spectra of an organic compound having hole-transporting properties, the emission spectra of an organic compound having electron-transporting properties, and the emission spectra of a mixed film formed by mixing these materials. When a phenomenon is observed in which the emission spectrum of the mixed film is shifted to the longer wavelength side (or has a new peak on the longer wavelength side) compared to the emission spectra of the respective materials, it indicates the formation of an exciplex. Alternatively, the transient photoluminescence (PL) of an organic compound having hole-transporting properties, the transient PL of an organic compound having electron-transporting properties, and the transient PL of a mixed film formed by mixing these materials are compared. When a difference in transient response is observed, such as a longer lifetime component or an increased ratio of a delayed component in the transient PL lifetime of the mixed film compared to the transient PL lifetimes of the respective materials, it indicates the formation of an exciplex. In addition, the above transient PL can be referred to as transient electroluminescence (EL). In other words, by comparing the transient EL of an organic compound having hole-transporting properties, the transient EL of an organic compound having electron-transporting properties, and the transient EL of a mixed film of these materials, and observing the difference in transient response, the formation of an exciplex can be confirmed.

[0229] The structure of the electron transport layer 114 is described in detail in Embodiment 1, so repeated description is omitted here. As the organic compound having electron-transporting properties, a substance having an electron mobility of 1×10 -7 cm 2 / Vs or more when the square root of the electric field strength [V / cm] is 600 is preferably used, and a substance having an electron mobility of 1×10 -6 cm 2 / Vs or more is more preferably used. In addition, as long as the substance has higher electron-transporting properties than hole-transporting properties, substances other than the above can be used. As the above organic compound, an organic compound containing a π-deficient heteroaromatic ring is preferably used. As the organic compound containing a π-deficient heteroaromatic ring, for example, an organic compound containing a heteroaromatic ring having a triazole skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, an organic compound containing a heteroaromatic ring having a diazine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton, any one or more of them are preferably used.

[0230] Note that the electron transport layer 114 may also have a stacked structure. In the case where the electron transport layer 114 has a stacked structure, preferably, all the layers in the stack have the structure as shown in Embodiment 1. In the case where the electron transport layer 114 in contact with the light-emitting layer 113 is used as a hole-blocking layer, a material having a HOMO energy level deeper by 0.5 eV or more than the HOMO energy level of the material contained in the light-emitting layer is preferably used.

[0231] The second electrode 102 is an electrode including a cathode. The second electrode 102 may also have a laminated structure, and in this case, the layer in contact with the organic compound layer 103 is used as the cathode. As the material for forming the cathode, metals, alloys, conductive compounds, and mixtures thereof with a small work function (specifically, 3.8 eV or less) 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) or ytterbium (Yb), and alloys containing them, etc.

[0232] In the case where the second electrode 102 is made of a material having transparency to visible light, a light-emitting device that emits light from the second electrode 102 side can be formed. In the case where the first electrode 101 is made of a material having transparency to visible light, a light-emitting device that emits light from the first electrode 101 side can be formed.

[0233] These conductive materials can be formed by dry methods such as vacuum evaporation or sputtering, inkjet methods, spin coating methods, etc. In addition, they can also be formed by wet methods such as sol-gel methods or wet methods using pastes of metal materials.

[0234] In addition, as a method for forming the organic compound layer 103, various methods can be used regardless of dry or wet methods. For example, vacuum evaporation, gravure printing, photogravure printing, screen printing, inkjet methods, or spin coating methods can also be used.

[0235] In addition, the above-mentioned electrodes or layers can also be formed by using different deposition methods.

[0236] In addition, each layer and electrode such as the above-mentioned organic compound layer 103 can be formed by methods such as evaporation (including vacuum evaporation), droplet ejection methods (also called inkjet methods), coating methods, gravure printing methods, etc. In addition, it can also include low molecular materials, medium molecular materials (including oligomers, dendrimers), or high molecular materials.

[0237] Figure 3A It is a diagram of two adjacent light-emitting devices (light-emitting device 130c, light-emitting device 130d) manufactured by photolithography.

[0238] The light-emitting device 130c includes an organic compound layer 103c between a first electrode 101c and a second electrode 102 on an insulating layer 175. The organic compound layer 103c includes a hole injection layer 111c, a hole transport layer 112c, a light-emitting layer 113c, an electron transport layer 114c, a first layer 119c, and a second layer 117c. Regardless of the presence or absence of a third layer.

[0239] The light-emitting device 130d includes an organic compound layer 103d between a first electrode 101d and a second electrode 102 on an insulating layer 175. The organic compound layer 103d includes a hole injection layer 111d, a hole transport layer 112d, a light-emitting layer 113d, an electron transport layer 114d, a first layer 119d, and a second layer 117d. Regardless of the presence or absence of a third layer.

[0240] In the organic compound layer 103c and the organic compound layer 103d, the first layer 119c and the second layer 117c, the first layer 119d and the second layer 117d, and the electron transport layer 114c and the electron transport layer 114d preferably have the structures shown in Embodiment 1.

[0241] Note that the second electrode 102 is preferably a continuous layer shared by the light-emitting device 130c and the light-emitting device 130d. In addition, since the organic compound layer 103c and the organic compound layer 103d are respectively processed by photolithography after forming the second layers 117c and 117d, they are independent of each other. In addition, the end portions (contours) of the organic compound layer 103c are processed by photolithography, so they are substantially aligned in the direction perpendicular to the substrate. In addition, the end portions (contours) of the organic compound layer 103d are processed by photolithography, so they are substantially aligned in the direction perpendicular to the substrate.

[0242] In addition, due to the processing by photolithography, there is a gap d between the organic compound layer 103c and the organic compound layer 103d. In addition, since the organic compound is processed by photolithography, the distance between the first electrode 101c and the first electrode 101d can be made smaller than that distance during mask evaporation, that is, it can be 2 μm or more and 5 μm or less. In addition, an insulating layer can be provided between the intervals d, and there is a structure in which the insulating layer is in contact with the second electrode 102.

[0243] In addition, Figure 3A The structure shown can also be used for an inverted stack structure. Figure 3B The light-emitting devices 130c and 130d shown have the above-mentioned inverted stack structure. Figure 3BThe organic compound layer 103c shown has a stacked structure in which a second electrode 102c, a second layer 117c, a first layer 119c, an electron transport layer 114c, a light-emitting layer 113c, a hole transport layer 112c, a hole injection layer 111c, and a first electrode 101 are sequentially stacked from the side of the insulator 175. In addition, Figure 3B The organic compound layer 103d shown has a stacked structure in which a second electrode 102d, a second layer 117d, a first layer 119d, an electron transport layer 114d, a light-emitting layer 113d, a hole transport layer 112d, a hole injection layer 111d, and a first electrode 101 are sequentially stacked from the side of the insulator 175. When using a light-emitting device having this reverse stacked structure, the relatively stable hole injection layers 111c and 111d become the surface, whereby a light-emitting device with better reliability can be realized.

[0244] Figure 3A The first layer 119c and the first layer 119d, and the second layer 117c and the second layer 117d can also be continuous layers shared by the light-emitting device 130c and the light-emitting device 130d. Figure 4 The light-emitting device 130c and the light-emitting device 130d shown are processed by photolithography for the hole injection layer 111c, the hole transport layer 112c, the light-emitting layer 113c, the electron transport layer 114c, the hole injection layer 111d, the hole transport layer 112d, the light-emitting layer 113d, and the electron transport layer 114d, so they are independent of each other, and the first layer 119, the second layer 117, and the second electrode 102 formed later are continuous layers shared by them.

[0245] In addition, a part of the end (outline) of the organic compound layer 103c is processed by photolithography, so it is substantially consistent in the direction perpendicular to the substrate. In addition, a part of the end (outline) of the organic compound layer 103d is processed by photolithography, so it is substantially consistent in the direction perpendicular to the substrate.

[0246] In addition, due to the processing by photolithography, there is a gap d between the organic compound layer 103c and the organic compound layer 103d. In addition, since the organic compound is processed by photolithography, the distance between the first electrode 101c and the first electrode 101d can be made smaller than this distance during mask evaporation, that is, it can be 2 μm or more and 5 μm or less. In addition, an insulating layer can be provided in the gap d, and the insulating layer is in contact with the first layer 119.

[0247] In one embodiment of the present invention, a light-emitting element processes an organic compound layer using photolithography, whereby processing can be performed with sufficient precision to fabricate a high-definition display device. In addition, since the layers 117 and 119 (DLL and CGL1 in Embodiment 1) far from the light-emitting layer can be subjected to a photolithography process without being contaminated by alkali metals, a light-emitting element having good characteristics can be realized. As described above, a light-emitting element according to one embodiment of the present invention having the above structure can realize a high-definition display device and a light-emitting element having good characteristics.

[0248] In addition, since the organic compound layer of a light-emitting element according to one embodiment of the present invention is processed simultaneously using photolithography, the profiles of the layers included in the organic compound layer are substantially identical. Here, "substantially identical" in this specification means that the difference between the profile A of layer A and the profile 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 profile of the part being compared. In addition, when the end face of the organic compound layer has a tapered shape, continuous change of the profile is allowed.

[0249] The structure of the present embodiment can be used in appropriate combination with other structures.

[0250] (Embodiment 3)

[0251] In the present embodiment, a mode in which a light-emitting device according to one embodiment of the present invention is used as a display element of a display device will be described.

[0252] As Figure 5A and Figure 5B shown, a plurality of light-emitting devices 130 are formed on an insulating layer 175 and constitute a display device.

[0253] The display device includes a pixel portion 177 in which a plurality of pixels 178 are arranged in a matrix. The pixel 178 includes a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0254] In this specification and the like, for example, when describing the common content among the sub-pixels 110R, the sub-pixels 110G, and the sub-pixels 110B, it is sometimes described as the sub-pixel 110. Similarly, when describing the common content among other constituent elements distinguished by letters, it is sometimes described using symbols with the letters omitted.

[0255] Sub-pixel 110R emits red light, sub-pixel 110G emits green light, and sub-pixel 110B emits blue light. Thus, an image can be displayed on pixel section 177. In the present embodiment, sub-pixels of three colors, red (R), green (G), and blue (B), are taken as an example for description, but a combination of sub-pixels of other colors may also be used. In addition, the number of sub-pixels is not limited to three, and four or more may be used. As four sub-pixels, for example, sub-pixels of four colors, R, G, B, and white (W); sub-pixels of four colors, R, G, B, and yellow (Y); and sub-pixels of four colors, R, G, B, and infrared light (IR); etc. can be cited.

[0256] In this specification and the like, the row direction is sometimes denoted as the X direction and the column direction is denoted as the Y direction. The X direction intersects with the Y direction, for example, perpendicularly.

[0257] In Figure 5A In the example shown, sub-pixels of different colors are arranged and configured in the X direction, and sub-pixels of the same color are arranged and configured in the Y direction. Note that sub-pixels of different colors may also be arranged and configured in the Y direction, and sub-pixels of the same color may be arranged and configured in the X direction.

[0258] A connection portion 140 is provided outside pixel section 177, and an area 141 may also be provided. Area 141 is provided between pixel section 177 and connection portion 140. An organic compound layer 103 is provided in area 141. In addition, a conductive layer 151C is provided in connection portion 140.

[0259] In the example shown in FIG. 5, area 141 and connection portion 140 are located on the right side of pixel section 177, but there is no particular limitation on the positions of area 141 and connection portion 140. In addition, area 141 and connection portion 140 may also be one or more.

[0260] Figure 5B is an example of a cross-sectional view along the Figure 5A between the dotted lines A1 - A2 in. As Figure 5A shown, the display device includes an insulating layer 171, a conductive layer 172 on insulating layer 171, an insulating layer 173 on insulating layer 171 and on conductive layer 172, an insulating layer 174 on insulating layer 173, and an insulating layer 175 on insulating layer 174. Insulating layer 171 is provided on a substrate (not shown). Insulating layer 175, insulating layer 174, and insulating layer 173 are provided with openings reaching conductive layer 172, and plugs 176 are provided in such a way as to be embedded in the openings.

[0261] In the pixel portion 177, a light-emitting device 130 is provided on the insulating layer 175 and the plug 176. In addition, a protective layer 131 is provided so as to cover the light-emitting device 130. The substrate 120 is bonded to the protective layer 131 by a resin layer 122. Further, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are preferably provided between adjacent light-emitting devices 130.

[0262] Figure 5B A cross-section showing a plurality of inorganic insulating layers 125 and a plurality of insulating layers 127 is shown, but when the display device is viewed from above, the inorganic insulating layer 125 and the insulating layer 127 are preferably formed as a connected single layer, respectively. In other words, the insulating layer 127 is preferably an insulating layer having an opening portion on the first electrode.

[0263] In Figure 5B the light-emitting devices 130R, 130G, and 130B are shown as the light-emitting device 130. The light-emitting devices 130R, 130G, and 130B can emit light of different colors from each other. For example, the light-emitting device 130R can emit red light, the light-emitting device 130G can emit green light, and the light-emitting device 130B can emit blue light. In addition, the light-emitting device 130R, 130G, or 130B can also emit other visible light or infrared light.

[0264] A display device according to one embodiment of the present invention can have, for example, a top emission structure that emits light in a direction opposite to the substrate on which the light-emitting device is formed. In addition, a display device according to one embodiment of the present invention can also have a bottom emission structure.

[0265] The light-emitting device 130R has the structure shown in Embodiment 1 and Embodiment 2. The light-emitting device 130R includes a first electrode 101R (pixel electrode) composed of a conductive layer 151R and a conductive layer 152R, a first EL layer 104R on the first electrode 101R, an organic compound layer (a second EL layer 105 on the first EL layer 104R), and a second electrode 102 (common electrode) on the second EL layer 105. The second EL layer 105 is preferably located closer to the second electrode 102 (common electrode) than the light-emitting layer, and is preferably an electron transport layer or a layer overlapping with the electron transport layer (DLL and CGL1 in Embodiment 1) or a laminate thereof. By having this structure, damage to the light-emitting layer or the active layer in the photolithography process can be suppressed, and good film quality and electrical characteristics can be expected. In addition, several layers such as an electron injection layer can be included as a common layer in contact with the second electrode 102 (common electrode).

[0266] The light-emitting device 130G has the structures shown in Embodiment 1 and Embodiment 2. The light-emitting device 130G includes a first electrode 101G (pixel electrode) composed of a conductive layer 151G and a conductive layer 152G, a first EL layer 104G on the first electrode 101G, a second EL layer 105 on the first EL layer 104G, and a second electrode 102 (common electrode) on the second EL layer 105. The second EL layer 105 is preferably an electron transport layer or a layer overlapping with the electron transport layer (DLL and CGL1 in Embodiment 1) or a laminate thereof.

[0267] The light-emitting device 130B has the structures shown in Embodiment 1 and Embodiment 2. The light-emitting device 130B includes a first electrode 101B (pixel electrode) composed of a conductive layer 151B and a conductive layer 152B, a first EL layer 104B on the first electrode 101B, a second EL layer 105 on the first EL layer 104B, and a second electrode 102 (common electrode) on the second EL layer 105. The second EL layer 105 is preferably an electron transport layer or a layer overlapping with the electron transport layer (DLL and CGL1 in Embodiment 1) or a laminate thereof.

[0268] One of the pixel electrode (first electrode) and the common electrode (second electrode) included in the light-emitting device is used as the anode, and the other is used as the cathode. In the present 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 for description.

[0269] The first EL layer 104R, the first EL layer 104G, and the first EL layer 104B are independent of each other in an island shape or independent of each other in an island shape for each emission color. Note that the first EL layer 104R, the first EL layer 104G, and the first EL layer 104B preferably do not overlap with each other. By arranging the first EL layer 104 in an island shape for each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can be suppressed even in a high-definition display device. Thereby, crosstalk can be prevented to realize a display device with extremely high contrast. In particular, a display device with high current efficiency at low brightness can be realized.

[0270] The island-shaped first EL layer 104 is formed by depositing an EL film and processing the EL film by photolithography.

[0271] The first EL layer 104 is preferably arranged so as to cover the top surface and the side surface of the first electrode 101 (pixel electrode) of the light-emitting device 130. Thereby, compared with a structure in which the end portion of the first EL layer 104 is located inside the end portion of the pixel electrode, it is easy to increase the aperture ratio of the display device. In addition, by covering the side surface of the pixel electrode of the light-emitting device 130 with the first EL layer 104, contact between the pixel electrode and the second electrode 102 can be suppressed, and thus short circuit of the light-emitting device 130 can be suppressed.

[0272] In a display device according to one embodiment of the present invention, the first electrode 101 (pixel electrode) of the light-emitting device preferably has a stacked structure. For example, in Figure 5B the example shown, the first electrode 101 of the light-emitting device 130 has a stacked structure including a conductive layer 151 provided on one side of the insulating layer 171 and a conductive layer 152 provided on one side of the organic compound layer.

[0273] As the conductive layer 151, for example, a metal material can be used. Specifically, for example, 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), etc., and alloys obtained by appropriately combining them can be used.

[0274] As the conductive layer 152, an oxide containing any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, a conductive oxide including any one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon is preferably used. In particular, the indium tin oxide containing silicon has a relatively large work function, and its work function is, for example, 4.0 eV or more, so it can be suitably used as the conductive layer 152.

[0275] The conductive layer 151 and the conductive layer 152 may each have a stacked structure including a plurality of layers containing different materials. In this case, the conductive layer 151 may include a layer using a material that can be used for the conductive layer 152, such as a conductive oxide, and the conductive layer 152 may include a layer using a material that can be used for the conductive layer 151, such as a metal material. For example, when the conductive layer 151 has a stacked structure of two or more layers, the layer in contact with the conductive layer 152 may be a layer using a material that can be used for the conductive layer 152.

[0276] 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 less than 90°. At this time, the conductive layer 152 provided along the side surface of the conductive layer 151 also has a tapered shape. By making the side surface of the conductive layer 152 have a tapered shape, the coverage of the first EL layer 104 provided along the side surface of the conductive layer 152 can be improved.

[0277] Note that although Figure 5BThe structure is shown in which the second EL layer 105 has a continuous layer shared among the light-emitting devices 130R, 130G, and 130B across the top surface of the insulating layer 127, but other structures may also be employed. For example, Figure 6 The stacked structure of the first electrode 101R (101G, 101B) and the second EL layer 105 is shown. By adopting the above structure, a part of the end (outline) of the stacked structure of the first electrode 101R (101G, 101B) and the second EL layer 105 is processed by photolithography, so that they can be made substantially consistent in the direction perpendicular to the substrate. Since the processing is performed by photolithography, the distance between the light-emitting devices 130R, 130G, and 130B can be made smaller than that distance during mask evaporation.

[0278] In a display device according to one embodiment of the present invention, the light-emitting device 130 has the structure shown in Embodiment 1 and Embodiment 2, whereby a display device with good reliability can be realized.

[0279] Next, an example of a manufacturing method of a display device having the Figure 5A shown structure will be described with reference to FIGS. 7 to 12.

[0280] [Example of Manufacturing Method 1]

[0281] The thin films (such as insulating films, semiconductor films, and conductive films) constituting the display device can be formed by sputtering, chemical vapor deposition (CVD: Chemical Vapor Deposition), vacuum evaporation, pulsed laser deposition (PLD: Pulsed Laser Deposition), atomic layer deposition (ALD: Atomic Layer Deposition), or the like.

[0282] In addition, the thin films (such as insulating films, semiconductor films, and conductive films) constituting the display device can be formed by wet deposition methods such as spin coating, dipping, spraying, inkjet, dispenser, screen printing, offset printing, doctor knife, slot die coating, roll coating, curtain coating, or blade coating.

[0283] Further, when processing the thin films constituting the display device, for example, processing can be performed by photolithography.

[0284] In photolithography, as the light used for exposure, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or light obtained by mixing these lights can be used. In addition, ultraviolet light, KrF laser, ArF laser, etc. can also be used. Furthermore, immersion exposure technology can also be used for exposure. In addition, as the light used for exposure, extreme ultraviolet (EUV) light or X-rays can also be used. In addition, instead of the light used for exposure, an electron beam can also be used.

[0285] In the etching of a thin film, a dry etching method, a wet etching method, a sandblasting method, etc. can be used.

[0286] First, as Figure 7A 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 so as to cover the conductive layer 172 and the conductive layer 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.

[0287] As the substrate, a substrate having at least heat resistance capable of withstanding the subsequent heat treatment can be used. For example, a glass substrate; a quartz substrate; a sapphire substrate; a ceramic substrate; an organic resin substrate; or a semiconductor substrate such as a single crystal semiconductor substrate or a polycrystalline semiconductor substrate made of silicon or silicon carbide, etc., a compound semiconductor substrate such as silicon germanium, an SOI substrate, etc. can be used.

[0288] Next, as Figure 7A shown, an opening reaching the conductive layer 172 is formed in the insulating layer 175, the insulating layer 174, and the insulating layer 173. Next, a plug 176 is formed so as to fill the opening.

[0289] Next, as Figure 7A shown, a conductive film 151f that will become a conductive layer 151R, a conductive layer 151G, a conductive layer 151B, and a conductive layer 151C later is formed on the plug 176 and the insulating layer 175. As the conductive film 151f, for example, a metal material can be used.

[0290] Next, as Figure 7A shown, a resist mask 191 is formed on the conductive film 151f. The resist mask 191 can be formed by coating a photosensitive material (photoresist) and performing exposure and development.

[0291] Next, as Figure 7B shown, for example, the conductive film 151f in a region not overlapping with the resist mask 191 is removed. Thereby, the conductive layer 151 is formed.

[0292] Next, asFigure 7C As shown, the resist mask 191 is removed. The resist mask 191 can be removed, for example, by ashing using oxygen plasma.

[0293] Next, as Figure 7D shown, an insulating film 156f that will later become the insulating layers 156R, 156G, 156B, and 156C is formed on the conductive layers 151R, 151G, 151B, 151C, and the insulating layer 175.

[0294] The insulating film 156f can be an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitrogen oxide insulating film. For example, silicon oxynitride can be used.

[0295] Next, as Figure 7E shown, the insulating layers 156R, 156G, 156B, and 156C are formed by processing the insulating film 156f.

[0296] Next, as Figure 8A shown, a conductive film 152f is formed on the conductive layers 151R, 151G, 151B, 151C, the insulating layers 156R, 156G, 156B, 156C, and the insulating layer 175.

[0297] As the conductive film 152f, for example, a conductive oxide can be used. The conductive film 152f can also have a stacked structure.

[0298] Next, as Figure 8B shown, the conductive film 152f is processed to form the conductive layers 152R, 152G, 152B, and 152C.

[0299] Next, as Figure 8C shown, an organic compound film 103Rf is formed on the conductive layers 152R, 152G, 152B, and the insulating layer 175. In addition, as Figure 8C shown, the organic compound film 103Rf is not formed on the conductive layer 152C.

[0300] Next, as Figure 8C shown, a sacrificial film 158Rf and a mask film 159Rf are formed.

[0301] By providing the sacrificial film 158Rf on the organic compound film 103Rf, damage to the organic compound film 103Rf during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be improved.

[0302] As the sacrificial film 158Rf, a film with high resistance to the processing conditions of the organic compound film 103Rf is used. Specifically, a film with a large etching selectivity ratio with respect to the organic compound film 103Rf. As the mask film 159Rf, a film with a large etching selectivity ratio with respect to the sacrificial film 158Rf is used.

[0303] In addition, the sacrificial film 158Rf and the mask film 159Rf are formed at a temperature lower than the heat-resistant temperature of the organic compound film 103Rf. The substrate temperature when forming 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.

[0304] As the sacrificial film 158Rf and the mask film 159Rf, a film that can be removed by a wet etching method or a dry etching method is preferably used.

[0305] In addition, the sacrificial film 158Rf formed in contact with the organic compound film 103Rf is preferably formed by a formation method that causes less damage to the organic compound film 103Rf than the mask film 159Rf. For example, compared with the sputtering method, the ALD method or the vacuum evaporation method is more preferably used.

[0306] As the sacrificial film 158Rf and the mask film 159Rf, for example, one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, and an inorganic insulating film can be used.

[0307] As the sacrificial film 158Rf and the mask film 159Rf, for example, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing the metal materials can be used respectively. In particular, low melting point materials such as aluminum or silver are preferably used. By using a metal material capable of shielding ultraviolet rays as one or both of the sacrificial film 158Rf and the mask film 159Rf, it is possible to suppress the ultraviolet rays during pattern exposure from irradiating the organic compound film 103Rf and suppress the deterioration of the organic compound film 103Rf, so it is preferred.

[0308] In addition, as the sacrificial film 158Rf and the mask film 159Rf, 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), indium-tin oxide containing silicon, etc. can be used respectively.

[0309] Note that element M (where M is one or more of aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) can also be used in the above metal oxide to replace the above gallium.

[0310] As the sacrificial film 158Rf and the mask film 159Rf, for example, a semiconductor material such as silicon or germanium is used. This has high affinity with the semiconductor manufacturing process and is thus preferred. In addition, a compound containing the above semiconductor material can be used.

[0311] As the sacrificial film 158Rf and the mask film 159Rf, various inorganic insulating films can be used respectively. In particular, the adhesion of the oxide insulating film to the organic compound film 103Rf is higher than that of the nitride insulating film to the organic compound film 103Rf, so it is preferred.

[0312] Next, as Figure 8C shown, a resist mask 190R is formed. The resist mask 190R can be formed by coating a photosensitive material (photoresist) and then performing exposure and development.

[0313] The resist mask 190R is provided at a position overlapping with the conductive layer 152R. The resist mask 190R is preferably also provided at a position overlapping with the conductive layer 152C. Thereby, damage to the conductive layer 152C during the manufacturing process of the display device can be suppressed.

[0314] Next, as Figure 8D shown, a part of the mask film 159Rf is removed using the resist mask 190R to form a mask layer 159R. The mask layer 159R remains on the conductive layer 152R and the conductive layer 152C. Then, the resist mask 190R is removed. Next, the mask layer 159R is used as a mask (also called a hard mask) to remove a part of the sacrificial film 158Rf to form a sacrificial layer 158R.

[0315] By using the wet etching method, compared with the case of using the dry etching method, damage to the organic compound film 103Rf during the processing of the sacrificial film 158Rf and the mask film 159Rf can be reduced. When using the wet etching method, for example, it is preferably to use a developer, an alkaline aqueous solution such as a tetramethylammonium hydroxide (TMAH) aqueous solution, or an acidic aqueous solution such as a dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixed liquid of them.

[0316] In addition, when using the dry etching method during the processing of the sacrificial film 158Rf, deterioration of the organic compound film 103Rf can be suppressed by not using an oxygen-containing gas as the etching gas.

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

[0318] Next, as Figure 8D shown, the organic compound film 103Rf is processed to form the organic compound layer 103R. For example, the mask layer 159R and the sacrificial layer 158R are used as hard masks and a part of the organic compound film 103Rf is removed, thereby forming the organic compound layer 103R.

[0319] Thus, as Figure 8D shown, a stacked structure of the organic compound layer 103R, the sacrificial layer 158R, and the mask layer 159R remains on the conductive layer 152R. In addition, the conductive layer 152G and the conductive layer 152B are exposed.

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

[0321] When using the dry etching method, by not using an oxygen-containing gas as the etching gas, deterioration of the organic compound film 103Rf can be suppressed.

[0322] In addition, an oxygen-containing gas may also be used as the etching gas. When the etching gas contains oxygen, the etching rate can be increased. Therefore, etching can be performed under low-power conditions while maintaining a sufficient etching rate. Therefore, damage to the organic compound film 103Rf can be suppressed. And, defects such as adhesion of reaction products generated during etching can be suppressed.

[0323] When using the dry etching method, for example, it is preferable to use a gas containing one or more of the group 18 elements such as H2, CF4, C4F8, SF6, CHF3, Cl2, H2O, BCl3, He, Ar, etc. as the etching gas. Alternatively, it is preferable to use a gas containing one or more of the above gases and oxygen as the etching gas. Alternatively, oxygen gas may also be used as the etching gas.

[0324] Next, as Figure 9A shown, the organic compound film 103Gf that will later become the organic compound layer 103G is formed.

[0325] The organic compound film 103Gf can be formed using the same method as that applicable to the formation of the organic compound film 103Rf. In addition, the organic compound film 103Gf can have the same structure as the organic compound film 103Rf.

[0326] Next, as Figure 9AAs shown, a sacrificial film 158Gf and a mask film 159Gf are formed in sequence. 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 the conditions applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the resist mask 190G are the same as the conditions applicable to the resist mask 190R.

[0327] The resist mask 190G is disposed at a position overlapping with the conductive layer 152G.

[0328] Next, as Figure 9B shown, a part of the mask film 159Gf is removed using the resist mask 190G, thereby forming a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. Then, the resist mask 190G is removed. Next, the mask layer 159G is used as a mask to remove a part of the sacrificial film 158Gf, thereby forming a sacrificial layer 158G. Next, the organic compound film 103Gf is processed to form an organic compound layer 103G. Thus, as Figure 9B shown, a stacked structure of the organic compound layer 103G, the sacrificial layer 158G, and the mask layer 159G remains on the conductive layer 152G. In addition, the mask layer 159R and the conductive layer 152B are exposed.

[0329] Next, as Figure 9C shown, an organic compound film 103Bf is formed.

[0330] The organic compound film 103Bf can be formed using the same method as applicable to the formation of the organic compound film 103Rf. In addition, the organic compound film 103Bf can have the same structure as the organic compound film 103Rf.

[0331] Next, as Figure 9C shown, a sacrificial film 158Bf and a mask film 159Bf are formed in sequence. Then, a resist mask 190B is formed. The materials and formation methods of the sacrificial film 158Bf and the mask film 159Bf are the same as the conditions applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the resist mask 190B are the same as the conditions applicable to the resist mask 190R.

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

[0333] Next, as Figure 9DAs shown, a part of the mask film 159Bf is removed using a resist mask 190B, thereby forming a mask layer 159B. The mask layer 159B remains on the conductive layer 152B. Then, the resist mask 190B is removed. Next, the mask layer 159B is used as a mask to remove a part of the sacrificial film 158Bf, thereby forming a sacrificial layer 158B. Next, the organic compound film 103Bf is processed to form an organic compound layer 103B. For example, the mask layer 159B and the sacrificial layer 158B are used as hard masks to remove a part of the organic compound film 103Bf, thereby forming the organic compound layer 103B.

[0334] Thus, as Figure 9D shown, a stacked structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B. In addition, the mask layer 159R and the mask layer 159G are exposed.

[0335] Note that the sides of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are each preferably perpendicular or substantially perpendicular to the formation surface. For example, the angle formed by the formation surface and these sides is preferably 60 degrees or more and 90 degrees or less.

[0336] As described above, the distance between two adjacent organic compound layers among the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B formed by 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. Here, for example, this distance can be defined based on the distance between the opposing ends of two adjacent organic compound layers among the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. Thus, by reducing the distance between the island-shaped organic compound layers, a display device with high clarity and a large aperture ratio can be provided. In addition, 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, 2 μm or less. In addition, 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 10A shown, it is preferable to remove the mask layer 159R, the mask layer 159G, and the mask layer 159B.

[0338] As the mask layer removal process, the same method as the mask layer processing process can be used. In particular, by using a wet etching method, compared with the case of using a dry etching method, the damage to the organic compound layer 103 during mask layer removal can be reduced.

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

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

[0341] Next, as Figure 10B shown, an inorganic insulating film 125f is formed.

[0342] Next, as Figure 10C shown, an insulating film 127f that will become the insulating layer 127 later is formed on the inorganic insulating film 125f.

[0343] When forming the inorganic insulating film 125f and the insulating film 127f, the substrate temperature 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 preferred to form an insulating film with a thickness of 3 nm or more, 5 nm or more, or 10 nm or more and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above substrate temperature range.

[0345] The inorganic insulating film 125f is preferably formed by the ALD method, for example. By using the ALD method, deposition damage can be reduced, and a film with high coverage can be deposited, so it is preferred. As the inorganic insulating film 125f, for example, an alumina film is preferably formed by the ALD method.

[0346] The insulating film 127f is preferably formed by the above wet deposition method. The insulating film 127f is preferably formed by spin coating using a photosensitive material, and more specifically, it is preferably formed using a photosensitive resin composition containing an acrylic resin.

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

[0348] By means of the exposed area of the insulating film 127f, the width of the insulating layer 127 to be formed later can be controlled. In the present embodiment, processing is performed such that the insulating layer 127 has a portion overlapping with the top surface of the conductive layer 151.

[0349] The light used for exposure preferably has i-line (wavelength 365 nm). Additionally, the light used for exposure may also have at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0350] Next, as Figure 11A shown, development is performed to remove the exposed area in the insulating film 127f to form the insulating layer 127a.

[0351] Next, as Figure 11B shown, the insulating layer 127a is used as a mask for etching to remove a part of the inorganic insulating film 125f, thereby reducing the thickness of a part of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B. As a result, an inorganic insulating layer 125 is formed under the insulating layer 127a. Additionally, the surfaces of the portions where the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B have a thin thickness are exposed. Hereinafter, the etching process using the 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 layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, the first etching process can be performed in one step, so it is preferred.

[0353] When performing dry etching, chlorine-based gases are preferably used. As the chlorine-based gas, one gas such as Cl2, BCl3, SiCl4, and CCl4 or a mixture of two or more of the above gases can be used. Additionally, one gas such as oxygen gas, hydrogen gas, helium gas, and argon gas or a mixture of two or more of the above gases can be appropriately added to the above chlorine-based gas. By using dry etching, regions with a thin thickness of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B can be formed with excellent in-plane uniformity.

[0354] As a dry etching apparatus, a dry etching apparatus having a high-density plasma source can be used. As a dry etching apparatus having a high-density plasma source, for example, an inductively coupled plasma (ICP) etching apparatus can be used. Alternatively, a capacitively coupled plasma (CCP) etching apparatus including parallel plate electrodes can be used.

[0355] In addition, it is preferred to perform the first etching treatment using wet etching. By using the wet etching method, the damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced compared to the case of using the dry etching method. For example, wet etching can be performed using an alkaline solution. For example, TMAH can be used as an alkaline solution in the wet etching of an aluminum oxide film. In addition, an acidic solution containing a fluoride can also be used. In this case, wet etching can be performed in a glue coating manner. When the inorganic insulating film 125f is deposited using the same material as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, the above-mentioned etching treatment can be performed at one time, so it is preferred.

[0356] In the first etching process, the sacrificial layers 158R, 158G, and 158B are not completely removed, and the etching process is stopped in a state where the thickness is reduced. In this way, by leaving the corresponding sacrificial layers 158R, 158G, and 158B on the organic compound layers 103R, 103G, and 103B, the organic compound layers 103R, 103G, and 103B can be prevented from being damaged in the subsequent process.

[0357] Next, the entire substrate is preferably exposed to visible light or ultraviolet light to irradiate the insulating layer 127a. The energy density of this exposure is preferably greater than 0 mJ / cm 2 And 800mJ / cm 2 Below, more preferably greater than 0 mJ / cm 2 And 500mJ / cm 2 By performing such exposure after development, the transparency of the insulating layer 127a can be improved. In addition, the substrate temperature required for heat treatment in a later step for deforming the insulating layer 127a into a tapered shape can be reduced.

[0358] Here, by providing an oxygen blocking insulating layer (for example, an aluminum oxide film) as the sacrificial layers 158R, 158G, and 158B, diffusion of oxygen into the organic compound layers 103R, 103G, and 103B can be reduced.

[0359] Next, a heat treatment (also called post-baking) is performed. By performing the heat treatment, the insulating layer 127a can be deformed into an insulating layer 127 having a tapered shape on its side. Figure 11C)。The heat treatment is performed at a temperature lower than the heat-resistant temperature of the organic compound layer. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, more preferably 70°C or higher and 130°C or lower. The heating atmosphere can be either an air atmosphere or an inert gas atmosphere. In addition, the heating atmosphere can be either an air atmosphere or a reduced-pressure atmosphere. Thereby, the adhesion between the insulating layer 127 and the inorganic insulating layer 125 can be improved, and the corrosion resistance of the insulating layer 127 can also be improved.

[0360] In the first etching process, by not completely removing the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B and leaving the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B in a state where their thicknesses are thinned, it is possible to prevent the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B from being damaged and deteriorated during the heat treatment. Thereby, the reliability of the light-emitting device can be improved.

[0361] Next, as Figure 12A shown, using the insulating layer 127 as a mask, an etching process is performed to remove a part of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B. Thereby, openings are formed in each of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, and the top surfaces of the organic compound layer 103R, the organic compound layer 103G, the organic compound layer 103B, and the conductive layer 152C are exposed. Note that the following sometimes refers to this etching process as the second etching process.

[0362] The end portion of the inorganic insulating layer 125 is covered by the insulating layer 127. In addition, Figure 12A shows an example in which a part of the end portion 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, the second etching process is performed using wet etching. By using the wet etching method, the damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced compared with the case of using the dry etching method. For example, wet etching can be performed using an alkaline solution or an acidic solution. In order to prevent the organic compound layer 103 from dissolving, wet etching is preferably performed using an aqueous solution.

[0364] Next, as Figure 12B shown, a common electrode 155 is formed on the organic compound layer 103R, the organic compound layer 103G, the organic compound layer 103B, the conductive layer 152C, and the insulating layer 127. The common electrode 155 can be formed by a method such as sputtering or vacuum evaporation. At this time, as Figure 5BAs shown, the organic compound layer 103 may also be formed into a stacked structure of a first EL layer 104 and a second EL layer 105, and a common electrode 155 is formed thereon.

[0365] Next, as Figure 12C 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 method, or ALD method.

[0366] Next, the substrate 120 is bonded to the protective layer 131 using the resin layer 122, whereby a display device can be manufactured. As described above, in the manufacturing method of the display device according to one embodiment of the present invention, the insulating layer 156 is provided in a manner including a region overlapping the side surface of the conductive layer 151, and the conductive layer 152 is formed so as to cover the conductive layer 151 and the insulating layer 156. Thereby, the yield of the display device can be improved, and the occurrence of defects can be suppressed.

[0367] As described above, in the manufacturing method of the display device according to one embodiment of the present invention, the island-shaped organic compound layer 103R, the island-shaped organic compound layer 103G, and the island-shaped organic compound layer 103B are not formed using a high-precision metal mask but are formed by depositing a film on one surface and then processing. Therefore, the island-shaped layers can be formed with a uniform thickness. And a high-definition display device or a display device with a high aperture ratio can be realized. In addition, even if the definition or aperture ratio is high and the distance between sub-pixels is extremely short, it is possible to suppress the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B from contacting each other in adjacent sub-pixels. Therefore, it is possible to suppress the occurrence of leakage current between sub-pixels. Thereby, crosstalk can be prevented to realize a display device with extremely high contrast. In addition, even for a display device including a light-emitting device manufactured by photolithography, a display device with good characteristics can be provided.

[0368] (Embodiment 4)

[0369] In this embodiment, a display device according to one embodiment of the present invention will be described.

[0370] The display device of this embodiment can be a high-definition display device. Therefore, for example, the display device of this embodiment can be used as a display unit of information terminal devices (wearable devices) such as watch-type and bracelet-type, and a display unit of wearable devices that can be worn on the head such as VR devices (HMD) and glasses-type AR devices.

[0371] In addition, the display device of the present embodiment can be a high-resolution display device or a large display device. Therefore, for example, the display device of the present embodiment can be used as the display unit of the following devices: electronic devices with a large screen such as a television device, a desktop or notebook personal computer, a display for a computer, etc., a digital signage, a large game machine such as a pachinko machine, etc.; a digital camera; a digital video camera; a digital photo frame; a mobile phone; a portable game machine; a portable information terminal; and a sound reproduction device.

[0372] [Display module]

[0373] Figure 13A A perspective view showing the display module 280 is presented. The display module 280 includes the display device 100A and the FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, and can also be any one of the display devices 100B and 100E to be described later.

[0374] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display portion 281. The display portion 281 is the image display area in the display module 280, and light from each pixel provided in the following pixel portion 284 can be seen.

[0375] Figure 13B It is a perspective schematic diagram of the structure on the side of the substrate 291. A circuit portion 282 is laminated on the substrate 291, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283. In addition, a terminal portion 285 for connecting to the FPC 290 is provided on a portion that does not overlap with the pixel portion 284 of the substrate 291. The terminal portion 285 and the circuit portion 282 are electrically connected through a wiring portion 286 composed of a plurality of wirings.

[0376] The pixel portion 284 includes a plurality of pixels 284a arranged periodically. Figure 13B An enlarged view of one pixel 284a is shown on the right side. The pixel 284a can adopt various structures described in the above embodiments. Figure 13B An example is shown in which the pixel 284a has the same structure as the pixel 178 shown in FIG. 5.

[0377] The pixel circuit portion 283 includes a plurality of pixel circuits 283a arranged periodically.

[0378] One pixel circuit 283a controls the driving of a plurality of elements included in one pixel 284a.

[0379] The circuit unit 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit unit 283. For example, it preferably includes one or both of a gate line driving circuit and a source line driving circuit. In addition, it may include at least one of a calculation circuit, a storage circuit, and a power supply circuit.

[0380] The FPC 290 is used as wiring for supplying video signals, power supply potential, and the like from the outside to the circuit portion 282. Alternatively, an IC may be mounted on the FPC 290.

[0381] The display module 280 may have a structure in which one or both of the pixel circuit portion 283 and the circuit portion 282 are stacked on the lower side of the pixel portion 284 , so that the display portion 281 may have an extremely high aperture ratio (effective display area ratio).

[0382] This high-definition display module 280 is suitable for use in VR devices such as HMD or glasses-type AR devices. For example, because the display module 280 has a display unit 281 with extremely high definition, in a structure where the display unit of the display module 280 is viewed through a lens, even if the display unit is magnified by the lens, the pixels cannot be seen, thereby achieving a highly immersive display. In addition, the display module 280 can also be applied to electronic devices with a relatively small display unit.

[0383] [Display device 100A]

[0384] Figure 14A The display device 100A shown includes a substrate 301 , a light emitting device 130R, a light emitting device 130G, a light emitting device 130B, a capacitor 240 , and a transistor 310 .

[0385] Substrate 301 is equivalent to Figure 13A and Figure 13B The transistor 310 is a transistor having a channel formation region in the substrate 301. As the substrate 301, for example, a semiconductor substrate such as a single crystal silicon substrate can be used. 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 is used as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and is used as a gate insulating layer. The low resistance region 312 is a region doped with impurities in the substrate 301 and is used as a source or a drain. The insulating layer 314 covers the side of the conductive layer 311.

[0386] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0387] In addition, an insulating layer 261 is provided to cover the transistor 310 , and the capacitor 240 is provided over the insulating layer 261 .

[0388] 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.

[0389] The conductive layer 241 is disposed on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain of the transistor 310 through a plug 271 embedded in the insulating layer 261. The insulating layer 243 is disposed so as to cover the conductive layer 241. The conductive layer 245 is disposed in a region overlapping the conductive layer 241 with the insulating layer 243 therebetween.

[0390] An insulating layer 255 is disposed so as to cover the capacitor 240. An insulating layer 174 is disposed on the insulating layer 255, and an insulating layer 175 is disposed on the insulating layer 174. Light-emitting devices 130R, 130G, and 130B are disposed on the insulating layer 175. An insulator is disposed in a region between adjacent light-emitting devices.

[0391] An insulating layer 156R is disposed so as to include a region overlapping the side surface of the conductive layer 151R, an insulating layer 156G is disposed so as to include a region overlapping the side surface of the conductive layer 151G, and an insulating layer 156B is disposed so as to include a region overlapping the side surface of the conductive layer 151B. In addition, a conductive layer 152R is disposed so as to cover the conductive layer 151R and the insulating layer 156R, a conductive layer 152G is disposed so as to cover the conductive layer 151G and the insulating layer 156G, and a conductive layer 152B is disposed so as to cover the conductive layer 151B and the insulating layer 156B. A sacrificial layer 158R is located on the organic compound layer 103R, a sacrificial layer 158G is located on the organic compound layer 103G, and a sacrificial layer 158B is located on the organic compound layer 103B.

[0392] The conductive layers 151R, 151G, and 151B are electrically connected to one of the source and drain of the transistor 310 through plugs 256 embedded in the insulating layers 243, 255, 174, and 175, the conductive layer 241 embedded in the insulating layer 254, and the plug 271 embedded in the insulating layer 261. Various conductive materials can be used for the plugs.

[0393] In addition, a protective layer 131 is disposed on the light-emitting devices 130R, 130G, and 130B. A resin layer 122 adheres the substrate 120 to the protective layer 131. Details of the components from the light-emitting devices 130 to the substrate 120 can be referred to in Embodiment 3. The substrate 120 corresponds to Figure 13A the substrate 292.

[0394] Figure 14B shows Figure 14A a modified example of the display device 100A shown. Figure 14B The display device shown includes a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B, and the light-emitting device 130 has an area overlapping one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. In Figure 14B the display device shown, the light-emitting device 130 can emit white light, for example. In addition, for example, the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B can transmit red light, green light, and blue light, respectively.

[0395] [Display device 100B]

[0396] Figure 15 shows a perspective view of the display device 100B, Figure 16 shows a cross-sectional view of the display device 100B.

[0397] The display device 100B has a structure in which a bonding substrate 352 and a substrate 351 are bonded. In Figure 15 this, the substrate 352 is indicated by a dashed line.

[0398] The display device 100B includes a pixel portion 177, a connection portion 140, a circuit 356, a wiring 355, and the like. Figure 15 shows an example in which an IC 354 and an FPC 353 are mounted on the display device 100B. Therefore, it is also possible to Figure 15 refer to the structure shown as a display module including the display device 100B, an IC (integrated circuit), and an FPC. Here, the substrate of the display device on which a connector such as an FPC is mounted or the substrate on which an IC is mounted is called a display module.

[0399] The connection portion 140 is provided outside the pixel portion 177. The connection portion 140 can be one or more. In the connection 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.

[0400] As the circuit 356, for example, a scan line driving circuit can be used.

[0401] The wiring 355 has a function of supplying signals and power to the pixel portion 177 and the circuit 356. The signals and power are input to the wiring 355 from the outside via the FPC 353 or input to the wiring 355 from the IC 354.

[0402] Figure 15An example of disposing the IC 354 on the substrate 351 by a method such as COG (Chip On Glass) or COF (Chip on Film) is shown. As the IC 354, for example, an IC including a scan line driving circuit or a signal line driving circuit or the like can be used. Note that the display device 100B and the display module do not necessarily have to be provided with an IC. In addition, for example, the IC can also be mounted on the FPC by the COF method.

[0403] Figure 16 An example of a cross-section of a part of the region including the FPC 353, a part of the circuit 356, a part of the pixel portion 177, a part of the connection portion 140, and a part of the region including the end portion of the display device 100B is shown.

[0404] [Display device 100C]

[0405] Figure 16 The shown display device 100C includes a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light, etc. between the substrate 351 and the substrate 352.

[0406] Details of the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B can be referred to in Embodiment 1 to Embodiment 3.

[0407] The 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. The 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. The 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.

[0408] 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 portion of the conductive layer 151R is located outside the end portion of the conductive layer 224R. The insulating layer 156R is provided in a manner including a region in contact with the side surface of the conductive layer 151R, and the conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R.

[0409] The conductive layer 224G, conductive layer 151G, conductive layer 152G, insulating layer 156G in the light-emitting device 130G, the conductive layer 224B, conductive layer 151B, conductive layer 152B, insulating layer 156B in the light-emitting device 130B, and the conductive layer 224R, conductive layer 151R, conductive layer 152R, insulating layer 156R in the light-emitting device 130R are the same, so detailed description is omitted.

[0410] In the conductive layer 224R, conductive layer 224G, and conductive layer 224B, recesses are formed in a manner of covering the openings provided in the insulating layer 214. The recesses are filled with the layer 128.

[0411] The layer 128 has a function of planarizing the recesses of the conductive layer 224R, conductive layer 224G, and conductive layer 224B. On the conductive layer 224R, conductive layer 224G, conductive layer 224B, and layer 128, conductive layers 151R, 151G, and 151B electrically connected to the conductive layer 224R, conductive layer 224G, and conductive layer 224B are provided. Therefore, the regions overlapping with the recesses of the conductive layer 224R, conductive layer 224G, and conductive layer 224B can also be used as light-emitting regions, and the aperture ratio of the pixels can be increased.

[0412] The layer 128 can also be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be appropriately used for the layer 128. In particular, the layer 128 is preferably formed of an insulating material, and more preferably formed of an organic insulating material. For example, the organic insulating material that can be used for the insulating layer 127 described above can be used for the layer 128.

[0413] A protective layer 131 is provided on the light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B. The protective layer 131 and the substrate 352 are bonded by an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. The light-emitting device 130 can be sealed by a solid-sealing structure or a hollow-sealing structure, etc. In Figure 16 this case, the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, that is, a solid-sealing structure is adopted. Alternatively, this space can also be filled with an inert gas (such as nitrogen or argon), that is, a hollow-sealing structure is adopted. At this time, the adhesive layer 142 can also be provided in a manner that does not overlap with the light-emitting device. In addition, this space can also be filled with a resin different from the adhesive layer 142 provided in a frame shape.

[0414] Figure 16An example is shown below: The connecting portion 140 includes a conductive layer 224C obtained by processing a conductive film identical to the conductive layers 224R, 224G, and 224B, a conductive layer 151C obtained by processing a conductive film identical to the conductive layers 151R, 151G, and 151B, and a conductive layer 152C obtained by processing a conductive film identical to the conductive layers 152R, 152G, and 152B. In addition, Figure 16 An example is shown in which the insulating layer 156C is provided in a manner that includes a region overlapping with the side surface of the conductive layer 151C.

[0415] The display device 100B is a top-emission type display device. The light-emitting device emits light toward the substrate 352 side. The substrate 352 is preferably made of a material with high visible light transmittance. When the light-emitting device emits infrared light or near-infrared light, a material with high transmittance for them is preferably used. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0416] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are sequentially provided on the substrate 351. A part of the insulating layer 211 serves as a gate insulating layer for each transistor. A part of the insulating layer 213 serves as a gate insulating layer for each transistor. The insulating layer 215 is provided so as to cover the transistors. The insulating layer 214 is provided so as to cover the transistors and serves as a planarization layer. In addition, there is no particular limitation on the number of gate insulating layers and the number of insulating layers covering the transistors, and it may be one or two or more.

[0417] An inorganic insulating film is preferably used as the insulating layer 211, the insulating layer 213, and the insulating layer 215.

[0418] The insulating layer 214 serving as a planarization layer preferably uses an organic insulating layer.

[0419] The transistors 201 and 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 electrodes; a semiconductor layer 231; an insulating layer 213 serving as a gate insulating layer; and a conductive layer 223 serving as a gate.

[0420] In a region of the substrate 351 that is not overlapped by the substrate 352, a connection portion 204 is provided. In the connection portion 204, a source electrode or a drain electrode of the transistor 201 is electrically connected to the FPC 353 through the conductive layer 166 and the connection layer 242. The following example is shown: the conductive layer 166 has a stacked structure of a conductive film obtained by processing a conductive film identical to the conductive layers 224R, 224G, and 224B, a conductive film obtained by processing a conductive film identical to the conductive layers 151R, 151G, and 151B, and a conductive film obtained by processing a conductive film identical to the conductive layers 152R, 152G, and 152B. The conductive layer 166 is exposed on the top surface of the connection portion 204. Therefore, the connection portion 204 can be electrically connected to the FPC 353 through the connection layer 242.

[0421] Preferably, a light-shielding layer 157 is provided on the surface of the substrate 352 on the side of the substrate 351. The light-shielding layer 157 can be provided between adjacent light-emitting devices, in the connection portion 140, the circuit 356, etc. In addition, various optical members can be arranged outside the substrate 352.

[0422] Each of the substrate 351 and the substrate 352 can adopt a material that can be used for the substrate 120.

[0423] As the adhesive layer 142, a material that can be used for the resin layer 122 can be used.

[0424] As the connection layer 242, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), etc. can be used.

[0425] [Display device 100D]

[0426] Figure 17 The shown display device 100D and Figure 16 The main difference between the shown display device 100D and the shown display device 100C is that the display device 100D is a bottom-emission type display device.

[0427] The light emitted by the light-emitting device is emitted to the side of the substrate 351. The substrate 351 preferably uses a material having high transmittance to visible light. On the other hand, there is no limitation on the light transmittance of the material used for the substrate 352.

[0428] 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 17 An example is shown in which a light-shielding layer 117 is provided on the substrate 351, an insulating layer 153 is provided on the light-shielding layer, and transistors 201, 205, etc. are provided on the insulating layer 153.

[0429] 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.

[0430] 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.

[0431] The conductive layers 112R, 112B, 126R, 126B, 129R, and 129B all use materials having high transmittance to visible light. As the common electrode 155, a material that reflects visible light is preferably used.

[0432] Note that although Figure 17 the light-emitting device 130G is not shown in

[0433] In addition, Figure 17 examples such as

[0434] [Display device 100E]

[0435] Figure 18 The shown display device 100E is Figure 16 a modified example of the shown display device 100C. The main difference between the display device 100E and the display device 100C is that the display device 100E includes a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B.

[0436] In the display device 100E, the light-emitting device 130 has an area overlapping one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. The coloring layer 132R, the coloring layer 132G, and the coloring layer 132B can be provided on the surface of the substrate 351 on the side of the substrate 352. The ends of the coloring layer 132R, the ends of the coloring layer 132G, and the ends of the coloring layer 132B can overlap the light-shielding layer 157.

[0437] In the display device 100E, the light-emitting device 130 can emit white light, for example. In addition, for example, the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B can transmit red light, green light, and blue light, respectively. In addition, the display device 100E can also adopt a structure in which the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B are provided between the protective layer 131 and the adhesive layer 142.

[0438] Figure 16 and Figure 18 examples such as

[0439] This embodiment can be appropriately combined with other embodiments or examples. In addition, in this specification, when multiple structural examples are shown in one embodiment, these structural examples can be appropriately combined.

[0440] (Embodiment 5)

[0441] In this embodiment, an electronic device of one aspect of the present invention will be described.

[0442] The electronic device of this embodiment includes a display device of one aspect of the present invention in a display unit. The display device of one aspect of the present invention has high display performance and is easily high-definition and high-resolution. Therefore, it can be used for the display units of various electronic devices.

[0443] Examples of electronic devices include, in addition to electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, monitors for computers, digital signage, large game machines such as pachinko machines, etc., digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, portable information terminals, sound reproduction devices, etc.

[0444] In particular, since the display device of one aspect of the present invention can improve clarity, it is suitable for use in electronic devices including relatively small display units. 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 VR devices like head-mounted displays, glasses-type AR devices, and MR devices.

[0445] The electronic device of this embodiment may also include a sensor (the sensor has a function of measuring factors such as force, displacement, position, speed, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, inclination, vibration, odor, or infrared rays).

[0446] Use Figures 19A to 19D An example of a wearable device that can be worn on the head will be described.

[0447] Figure 19A The shown electronic device 700A and Figure 19B The shown electronic device 700B both include a pair of display panels 751, a pair of outer shells 721, a communication unit (not shown), a pair of mounting parts 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a bezel 757, and a pair of nose pads 758.

[0448] The display panel 751 can apply the display device of one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0449] Both the electronic device 700A and the electronic device 700B can project the image displayed on the display panel 751 onto the display area 756 in the optical member 753. Since the optical member 753 has light transmissivity, the user can see the image displayed in the display area overlapping with the transmitted image seen through the optical member 753.

[0450] On the electronic device 700A and the electronic device 700B, a camera capable of photographing the front can also be provided as the imaging unit. In addition, by providing an acceleration sensor such as a gyro sensor on the electronic device 700A and the electronic device 700B, the user's head orientation can be detected and the image corresponding to that direction can be displayed on the display area 756.

[0451] The communication unit has a wireless communication device, and an image signal can be supplied through this wireless communication device, for example. In addition, instead of or in addition to the wireless communication device, a connector capable of connecting a cable for supplying an image signal and a power potential may be included.

[0452] In addition, the electronic device 700A and the electronic device 700B are provided with a battery and can be charged in one or both of a wireless manner and a wired manner.

[0453] The housing 721 may also be provided with a touch sensor module.

[0454] As the touch sensor module, various touch sensors can be used. For example, various methods such as the capacitive method, the resistive film method, the infrared method, the electromagnetic induction method, the surface acoustic wave method, and the optical method can be adopted. In particular, it is preferable to apply a capacitive or optical sensor to the touch sensor module.

[0455] Figure 19C The illustrated electronic device 800A and Figure 19D The illustrated electronic device 800B both 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.

[0456] The display unit 820 can apply the display device of one aspect of the present invention. Thus, a highly reliable electronic device can be realized.

[0457] The display unit 820 is provided at a position inside the housing 821 where it can be seen through the lens 832. In addition, by displaying different images on each of the pair of display units 820, three-dimensional display using parallax can be performed.

[0458] The electronic device 800A and the electronic device 800B preferably have a mechanism in which the left - 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 located at the most suitable positions according to the position of the user's eyes.

[0459] The user can mount the electronic device 800A or the electronic device 800B on the head using the mounting unit 823.

[0460] The imaging unit 825 has a 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 also be provided to be able to correspond to multiple perspectives such as telephoto and wide - angle.

[0461] The electronic device 800A can also include a vibration mechanism used as a bone - conduction headphone.

[0462] The electronic device 800A and the electronic device 800B can both include input terminals. Cables for supplying video signals from a video output device, etc., and power for charging a battery provided inside the electronic device can be connected to the input terminals.

[0463] The electronic device according to one aspect of the present invention can also have a function of performing wireless communication with the headphone 750.

[0464] In addition, the electronic device can also include a headphone unit. Figure 19B The illustrated electronic device 700B includes a headphone unit 727. A part of the wiring connecting the headphone unit 727 and the control unit can also be arranged inside the housing 721 or the mounting unit 723.

[0465] Similarly, Figure 19D The illustrated electronic device 800B includes a headphone unit 827. For example, a structure in which the headphone unit 827 and the control unit 824 are connected in a wired manner can be adopted.

[0466] Thus, as the electronic device according to one aspect of the present invention, both the glasses - type (such as the electronic device 700A and the electronic device 700B) and the goggles - type (such as the electronic device 800A and the electronic device 800B) are preferred.

[0467] Figure 20A The illustrated electronic device 6500 is a portable information terminal device that can be used as a smartphone.

[0468] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, etc. The display unit 6502 has a touch - panel function.

[0469] The display unit 6502 can use the display device according to one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0470] Figure 20B It is a schematic cross-sectional view of an end portion on the microphone 6506 side including the housing 6501.

[0471] A protective member 6510 having translucency is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, etc. are provided in a space surrounded by the housing 6501 and the protective member 6510.

[0472] The display panel 6511, the optical member 6512, and the touch sensor panel 6513 are fixed to the protective member 6510 using an adhesive layer (not shown).

[0473] In a region outside the display unit 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded-back part. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on the printed circuit board 6517.

[0474] The display panel 6511 can use the display device according to one aspect of the present invention. Thereby, an extremely lightweight electronic device can be realized. In addition, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted while suppressing the thickness of the electronic device. Further, by folding a part of the display panel 6511 to provide a connection portion with the FPC 6515 on the back surface of the pixel portion, a narrow-bezel electronic device can be realized.

[0475] Figure 20C An example of a television device is shown. In the television device 7100, a display unit 7000 is assembled in a housing 7171. A structure in which the housing 7171 is supported by a bracket 7173 is shown here.

[0476] The display unit 7000 can use the display device according to one aspect of the present invention. Thereby, a highly reliable electronic device can be realized.

[0477] It can be performed by using an operation switch provided in the housing 7171 and a separately provided remote operation machine 7151 Figure 20C the operation of the television device 7100 shown.

[0478] Figure 20DAn example of a notebook personal computer is shown. The notebook personal computer 7200 includes a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, etc. A display unit 7000 is assembled in the housing 7211.

[0479] The display unit 7000 can use the display device of one mode of the present invention. Thus, an electronic device with high reliability can be realized.

[0480] Figure 20E and Figure 20F An example of a digital sign is shown.

[0481] Figure 20E The shown digital sign 7300 includes a housing 7301, a display unit 7000, a speaker 7303, etc. In addition, it may further include an LED lamp, operation keys (including a power switch or an operation switch), connection terminals, various sensors, a microphone, etc.

[0482] Figure 20F A digital sign 7400 provided on a cylindrical column 7401 is shown. The digital sign 7400 includes a display unit 7000 provided along the curved surface of the column 7401.

[0483] In Figure 20E and Figure 20F the display device of one mode of the present invention can be used for the display unit 7000. Thus, an electronic device with high reliability can be realized.

[0484] The larger the display unit 7000 is, the more information can be provided at one time. The larger the display unit 7000 is, the more likely it is to attract people's attention. For example, the advertising effect can be improved.

[0485] As Figure 20E and Figure 20F shown, the digital sign 7300 or the digital sign 7400 preferably can be linked with an information terminal device 7311 such as a smart phone carried by a user or an information terminal device 7411 through wireless communication.

[0486] Figures 21A to 21G The shown electronic device includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), connection terminals 9006, a sensor 9007 (the sensor has a function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electric power, radiation, flow rate, humidity, inclination, vibration, odor or infrared ray), a microphone 9008, etc.

[0487] Figures 21A to 21GThe electronic device shown has various functions. For example, it can have the following functions: a function of displaying various information (such as still images, moving images, and text images) on a display unit; a function of a touch panel; a function of displaying a calendar, date, or time, etc.; a function of controlling processing by using various software (programs); a function of performing wireless communication; a function of reading and processing programs or data stored in a storage medium; etc.

[0488] Next, the Figures 21A to 21G electronic device shown will be described in detail.

[0489] Figure 21A is a perspective view showing a portable information terminal 9171. The portable information terminal 9171 can be used as a smart phone, for example. Note that in the portable information terminal 9171, a speaker 9003, a connection terminal 9006, a sensor 9007, etc. can also be provided. In addition, as the portable information terminal 9171, text or image information can be displayed on its multiple faces. In Figure 21A an example of displaying three icons 9050 is shown. In addition, information 9051 shown by a dotted rectangle can be displayed on other faces of the display unit 9001. As an example of the information 9051, information indicating receipt of an e-mail, SNS, phone call, etc.; a title of an e-mail or SNS, etc.; a sender's name of an e-mail or SNS, etc.; a date; a time; a battery level; and a radio wave intensity, etc. can be cited. Or, an icon 9050, etc. can be displayed at a position where the information 9051 is displayed.

[0490] Figure 21B is a perspective view showing a portable information terminal 9172. The portable information terminal 9172 has a function of displaying information on three or more faces of the display unit 9001. Here, an example where information 9052, information 9053, and information 9054 are respectively displayed on different faces is shown. For example, in a state where the portable information terminal 9172 is placed in an upper body pocket, a user can confirm the information 9053 displayed at a position seen from above the portable information terminal 9172.

[0491] Figure 21C is a perspective view showing a tablet terminal 9173. The tablet terminal 9173 can execute various application software such as a mobile phone, e-mail, reading and editing of articles, playing music, network communication, computer games, etc., for example. The tablet terminal 9173 includes a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front surface of a housing 9000, an operation key 9005 serving as an operation button on the left side surface of the housing 9000, and a connection terminal 9006 on the bottom surface.

[0492] Figure 21DFIG. 0 is a perspective view showing a wristwatch-type portable information terminal 9200. The portable information terminal 9200 can be used as, for example, a smart watch (registered trademark). In addition, the display surface of the display unit 9001 is curved, and display can be performed along the curved display surface. Further, the portable information terminal 9200 can perform a hands-free call, for example, by communicating with a headset capable of wireless communication. Further, by using the connection terminal 9006, the portable information terminal 9200 can perform data transfer with other information terminals or be charged. Charging can also be performed by wireless power supply.

[0493] Figures 21E to 21G FIG. 1 is a perspective view showing a foldable portable information terminal 9201. In addition, Figure 21E FIG. 2 is a perspective view of a state in which the portable information terminal 9201 is unfolded, Figure 21G FIG. 3 is a perspective view of a folded state, Figure 21F FIG. 4 is a perspective view of an intermediate state when converting from Figure 21E one of the states of Figure 21G to the other. The portable information terminal 9201 has good portability in the folded state, and has strong display browsability in the unfolded state because it has a seamlessly joined large display area. The display unit 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. The display unit 9001 can be curved, for example, in a range of a curvature radius of 0.1 mm or more and 150 mm or less.

[0494] This embodiment can be appropriately combined with other embodiments or examples. Further, in this specification, in a case where a plurality of structural examples are shown in one embodiment, the structural examples can be appropriately combined.

[0495] [Reference Signs]

[0496] 100A: Display device, 100B: Display device, 100C: Display device, 100E: Display device, 100D: Display device, 100: Insulator, 101c: First electrode, 101d: First electrode, 101B: First electrode, 101G: First electrode, 101R: First electrode, 101: First electrode, 102: Second electrode, 103c: Organic compound layer, 103d: Organic compound layer, 103B: Organic compound layer, 103Bf: Organic compound film, 103G: Organic compound layer, 103Gf: Organic compound film, 103R: Organic compound layer, 103Rf: Organic compound film, 103: Organic compound layer, 104: First EL layer, 104R: First EL layer, 104G: First EL layer, 104B: First EL layer, 105: Second EL layer, 110B: Sub-pixel, 110G: Sub-pixel, 110R: Sub-pixel, 110: Sub-pixel, 111: Hole injection layer, 111c: Hole injection layer, 111d: Hole injection layer, 112: Hole transport layer, 112c: Hole transport layer, 112d: Hole transport layer, 112R: Conductive layer, 112B: Conductive layer, 113: Light-emitting layer, 113a: Light-emitting layer, 113b: Light-emitting layer, 113c: Light-emitting layer, 113d: Light-emitting layer, 114: Electron transport layer, 114c: Electron transport layer, 114d: Electron transport layer, 117: Second layer, 117c: Second layer, 117d: Second layer, 119: First layer, 119c: First layer, 119d: First 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, 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: Coloring layer, 132G: Coloring layer, 132R: Coloring layer, 140: Connection portion, 141: Region, 142: Adhesive layer, 151B: Conductive layer, 151C: Conductive layer, 151f: Conductive film, 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: Plug, 177: Pixel portion, 178: Pixel, 179: Conductive layer, 190B: Resist mask, 190G: Resist mask, 190R: Resist mask, 191: Resist mask, 201: Transistor, 204: Connection portion, 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: Connection layer, 243: Insulating layer, 245: Conductive layer, 254: Insulating layer, 255: Insulating layer, 256: Plug, 261: Insulating layer, 271: Plug, 280: Display module, 281: Display portion, 282: Circuit portion, 283a: Pixel circuit, 283: Pixel circuit portion, 284a: Pixel, 284: Pixel portion, 285: Terminal portion, 286: Wiring portion, 290: FPC, 291: Substrate, 292: Substrate, 301: Substrate, 310: Transistor, 311: Conductive layer, 312: Low-resistance region, 313: Insulating layer, 314: Insulating layer, 315: Element isolation layer, 351: Substrate, 352: Substrate, 353: FPC, 354: IC, 355: Wiring, 356: Circuit, 700A: Electronic device, 700B: Electronic device, 721: Housing, 723: Wearable portion, 727: Headphone portion, 750: Headphone, 751: Display panel, 753: Optical member, 756: Display area, 757: Frame, 758: Nose pad, 800: Substrate, 800A: Electronic device, 800B: Electronic device, 801: First electrode, 802: Second electrode, 814: First layer, 816: Second layer, 820: Display portion, 821: Housing, 822: Communication portion, 823: Wearable portion, 824: Control portion, 825: Imaging portion, 827: Headphone portion, 832: Lens, 6500: Electronic device, 6501: Housing, 6502: Display portion, 6503: Power button, 6504: Button, 6505: Speaker, 6506: Microphone, 6507: Camera, 6508: Light source, 6510: Protection member, 6511: Display panel, 6512: Optical member, 6513: Touch sensor panel, 6515: FPC, 6516: IC, 6517: Printed circuit board, 6518: Battery, 7000: Display portion, 7100: Television device,7151: Remote operating machine, 7171: Housing, 7173: Bracket, 7200: Notebook personal computer, 7211: Housing, 7212: Keyboard, 7213: Pointing device, 7214: External connection port, 7300: Digital signage, 7301: Housing, 7303: Speaker, 7311: Information terminal device, 7400: Digital signage, 7401: Column, 7411: Information terminal device, 9000: Housing, 9001: Display unit, 9002: Camera, 9003: Speaker, 9005: Operation key, 9006: Connection terminal, 9007: Sensor, 9008: Microphone, 9050: Icon, 9051: Information, 9052: Information, 9053: Information, 9054: Information, 9055: Hinge, 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: 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 includes a light-emitting layer, an electron transport layer, a first layer, and a second layer, The electron transport layer is located between the light-emitting layer and the first layer, The electron transport layer is in contact with the first layer, The first layer is located between the electron transport layer and the second layer, The first layer has a function of blocking holes, The second layer contains an organic compound having hole-transporting properties and a substance having an acceptor property for the organic compound having hole-transporting properties, And the electron transport layer is a bipolar layer.

2. 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 includes a light-emitting layer, an electron transport layer, a first layer, and a second layer, The electron transport layer is located between the light-emitting layer and the first layer, The electron transport layer is in contact with the first layer, The first layer is located between the electron transport layer and the second layer, The first layer has a function of blocking holes, The second layer contains an organic compound having hole-transporting properties and a substance having an acceptor property for the organic compound having hole-transporting properties, And the HOMO energy level of the organic compound having the highest HOMO energy level among the organic compounds contained in the electron transport layer is -5.90 eV or more and -5.00 eV or less.

3. 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 includes a light-emitting layer, an electron transport layer, a first layer, and a second layer, The electron transport layer is located between the light-emitting layer and the first layer, The electron transport layer is in contact with the first layer, The first layer is located between the electron transport layer and the second layer, The first layer contains an organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more, The second layer contains an organic compound having hole-transporting properties and a substance having an acceptor property for the organic compound having hole-transporting properties, And the HOMO energy level of the organic compound having the highest HOMO energy level among the organic compounds contained in the electron transport layer is -5.90 eV or more and -5.00 eV or less.

4. The light-emitting device according to any one of claims 1 to 3, Wherein the first layer is in contact with the second layer.

5. The light-emitting device according to any one of claims 1 to 3, Wherein the distance between the first layer and the second layer is 1 nm or more and 10 nm or less.

6. The light-emitting device according to any one of claims 1 to 3, Wherein the LUMO energy level of the organic compound having the lowest LUMO energy level among the organic compounds contained in the electron transport layer is -3.15 eV or more and -2.50 eV or less.

7. The light-emitting device according to any one of claims 1 to 3, Wherein the electron transport layer contains an organic compound having an electron-transporting skeleton and a hole-transporting skeleton.

8. The light-emitting device according to claim 7, Wherein the electron-transporting skeleton is a π-deficient heteroaromatic ring, and the hole-transporting skeleton is a π-rich heteroaromatic ring.

9. The light-emitting device according to any one of claims 1 to 3, Wherein the electron transport layer contains an organic compound having an electron-transporting skeleton and an organic compound having a hole-transporting skeleton.

10. The light-emitting device according to claim 9, Wherein the electron-transporting skeleton is a π-deficient heteroaromatic ring, and the hole-transporting skeleton is a π-rich heteroaromatic ring.

11. The light-emitting device according to claim 3, Wherein the organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more does not have an electron-transporting skeleton.

12. The light-emitting device according to claim 3, Wherein the organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more has a guanidine skeleton.

13. The light-emitting device according to claim 3, Wherein the organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more has a 1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine skeleton.

14. The light-emitting device according to any one of claims 1 to 3, Wherein the first layer contains an organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more and an organic compound having electron-transporting properties.

15. The light-emitting device according to claim 14, Wherein the organic compound having a strong basicity with an acid dissociation constant pKa of 8 or more does not have an electron-donating property to the organic compound having electron-transporting properties.

16. The light-emitting device according to any one of claims 1 to 3, The spin density measured by electron spin resonance method for the first layer is 1×10 17 spins / cm 3 or less.

17. The light-emitting device according to claim 14, Wherein the LUMO energy level of the organic compound having electron-transporting properties is -3.00 eV or more and -2.00 eV or less.

18. The light-emitting device according to any one of claims 1 to 3, Wherein the second layer is a charge generation layer.

19. The light-emitting device according to any one of claims 1 to 3, Wherein the second layer is: a mixed layer of an organic compound having hole-transporting properties and a substance having an acceptor property to the organic compound having hole-transporting properties; or a stack of single films of the organic compound having hole-transporting properties and the substance having an acceptor property to the organic compound having hole-transporting properties.

20. The light-emitting device according to any one of claims 1 to 3, Wherein the second layer is in contact with the first electrode or the second electrode.

21. The light-emitting device according to any one of claims 1 to 3 further includes a third layer, Wherein the light-emitting layer is located between the third layer and the electron transport layer, and the third layer contains a second organic compound having hole-transporting properties and a substance having an acceptor property to the second organic compound having hole-transporting properties.

Images