Organic compound and light-emitting device

Abstract

To provide an organic compound and a light-emitting device comprising the organic compound with high emission efficiency.SOLUTION: An organic compound is represented by General Formula (G1). In the formula, R1 to R8 independently represent hydrogen (including deuterium), an alkyl group, a cycloalkyl group, an aromatic hydrocarbon group or the like, and Ar11 and Ar12 represent an aromatic hydrocarbon group or an aromatic heterocyclic group. n11 represents an integer of 0 to 3, and n12 represents an integer of 1 to 3.SELECTED DRAWING: None

Description

[Technical Field]

[0001] One embodiment of the present invention relates to an organic compound, a light-emitting element, a light-emitting device, a display module, a lighting module, a display device, a light-emitting device, an electronic device, a lighting device, and an electronic device. Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification etc. relates to an object, a method, or a manufacturing method. Alternatively, one embodiment of the present invention relates to a process, a machine, manufacture, or a composition of matter. Therefore, more specific examples of the technical field of one embodiment of the present invention disclosed in this specification include semiconductor devices, display devices, liquid crystal display devices, light-emitting devices, lighting devices, power storage devices, memory devices, imaging devices, driving methods thereof, and manufacturing methods thereof. [Background technology]

[0002] Light-emitting devices (organic EL devices) that utilize electroluminescence (EL) using organic compounds are becoming more and more common. The basic structure of these light-emitting devices is a pair of electrodes sandwiching an organic compound layer (EL layer) containing a light-emitting material between them. By applying a voltage to this device, carriers are injected, and the recombination energy of these carriers is utilized to emit light from the light-emitting material.

[0003] Since such light-emitting devices are self-luminous, when used as display pixels, they offer advantages such as higher visibility and no need for backlighting compared to liquid crystal displays, making them particularly suitable for flat panel displays. Another major advantage of displays using such light-emitting devices is that they can be fabricated to be thin and lightweight. Another feature is their extremely fast response time.

[0004] Furthermore, these light-emitting devices can emit light continuously in two dimensions, making it possible to obtain surface light emission. This is a feature that is difficult to obtain with point light sources such as incandescent bulbs and LEDs, or linear light sources such as fluorescent lamps, making them highly useful as surface light sources for lighting applications.

[0005] Displays and lighting devices using such light-emitting devices are suitable for a variety of electronic devices, but research and development is ongoing to find light-emitting devices with even better characteristics.

[0006] One of the problems often cited when discussing organic EL devices is their low light extraction efficiency. To improve this, a structure has been proposed in which a layer made of a low refractive index material is formed inside the EL layer (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] US Patent Application Publication No. 2020 / 0176692 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of one embodiment of the present invention is to provide a light-emitting device with high emission efficiency, or to provide a light-emitting device, a light-emitting apparatus, an electronic device, a display device, or an electronic device with low power consumption.

[0009] The present invention is intended to solve any one of the above problems. [Means for solving the problem]

[0010] One embodiment of the present invention is an organic compound represented by general formula (G1).

[0011] [ka]

[0012] In the above formula, R 1 ~R 4 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-1), and R 5 ~R 8 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-3), and R 5 ~R 8 At least one of the groups is a substituent represented by the following general formula (G1-3), and Ar 11 represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 12 represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms. n11 represents an integer of 0 to 3, and n12 represents an integer of 1 to 3.

[0013] [ka]

[0014] In the above formula, Ar 13 , Ar 15 , and Ar 16 each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 14 , and Ar 17each independently represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 15 , Ar 16 and Ar 17 At least two of n13 represent a bicyclic or tricyclic monovalent or divalent aromatic hydrocarbon group, or a monovalent or divalent aromatic heterocyclic group. n13 represents an integer of 0 to 3, and n14, n15, n16, and n17 each independently represent an integer of 1 to 3. n15 + n16 + n17 > n13 + n14.

[0015] In the above general formula (G1), general formula (G1-1), and general formula (G1-3), Ar 15 , Ar 16 and Ar 17 At least two of the compounds are naphthalenes, and each naphthalene is bonded to another substituent at the 2-position.

[0016] In the above general formula (G1), general formula (G1-1), and general formula (G1-3), Ar 16 and Ar 17 is an organic compound in which each naphthalene is bonded to the 2-position and has 2,2'-binaphthalene as a partial structure.

[0017] One embodiment of the present invention is an organic compound represented by general formula (G1).

[0018] [ka]

[0019] In the above formula, R 1 ~R 4 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-1), and R 5 ~R8 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-2), and R 5 ~R 8 At least one of the groups is a substituent represented by the following general formula (G1-2), and Ar 11 represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 12 represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 14 to 30 carbon atoms, or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms. n11 represents an integer of 0 to 3, and n12 represents an integer of 1 to 3.

[0020] [ka]

[0021] In the above formula, Ar 13 , and Ar 15 each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 14 and Ar 17 each independently represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 15 , or Ar 17 At least one of the groups is phenanthrene, and Ar 17 When n13 is phenanthrene, it is bonded to another group at the 2nd or 3rd position of the phenanthrene. n13 represents an integer of 0 to 3, and n14, n15, and n17 each independently represent an integer of 1 to 3. n15 + n17 > n13 + n14.

[0022] In the above general formula (G1), general formula (G1-1), and general formula (G1-2), Ar 11 ~Ar 17 each independently represents an aromatic hydrocarbon group.

[0023] In the above general formula (G1), general formula (G1-1), and general formula (G1-2), the organic compound has a deposition temperature of 330° C. or less.

[0024] One embodiment of the present invention is an organic compound represented by structural formula (100), structural formula (101), structural formula (102), structural formula (123), or structural formula (150).

[0025] [ka]

[0026] The electronic device includes an organic compound represented by general formula (G1).

[0027] One embodiment of the present invention is a light-emitting device having a cap layer made of an organic compound having a carbazole ring and a phenanthrene ring.

[0028] One aspect of the present invention is a light-emitting device having a cap layer made of an organic compound having a carbazole ring and two to four naphthalene rings.

[0029] In the light-emitting device, the organic compound used in the cap layer has an ordinary refractive index no of 1.9 or more and an ordinary extinction coefficient ko of 0.2 or less at 450 nm.

[0030] In the light-emitting device, the organic compound used in the cap layer has an ordinary refractive index no of 1.8 or more and an ordinary extinction coefficient ko of 0.2 or less at 520 nm.

[0031] In the light-emitting device, the organic compound used in the cap layer has an ordinary refractive index no of 1.75 or more and an ordinary extinction coefficient ko of 0.2 or less at 630 nm.

[0032] One embodiment of the present invention is a light-emitting device that includes an organic compound represented by general formula (G1), in which the difference between the ordinary refractive index no and the extraordinary refractive index ne is 0.1 to 0.4 at a wavelength greater than or equal to 360 nm and less than or equal to 830 nm.

[0033] [ka]

[0034] In the above formula, R 1 ~R 4 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-1), and R 5 ~R 8 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-3), and R 5 ~R 8 At least one of the groups is a substituent represented by the following general formula (G1-3), and Ar 11 represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 12 represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms. n11 represents an integer of 0 to 3, and n12 represents an integer of 1 to 3.

[0035] [ka]

[0036] In the above formula, Ar13 , Ar 15 , and Ar 16 each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 14 , and Ar 17 each independently represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 15 , Ar 16 and Ar 17 At least two of n13, n15, and n16 represent a bicyclic or tricyclic monovalent or divalent aromatic hydrocarbon group, or a monovalent or divalent aromatic heterocyclic group. n13, n15, and n16 each independently represent an integer of 0 to 3, and n14 and n17 each independently represent an integer of 1 to 3. n15 + n16 + n17 ≧ n13 + n14.

[0037] One embodiment of the present invention is a light-emitting device in which the organic compound represented by the general formula (G1) is vapor-deposited at a temperature of 330° C. or lower.

[0038] One embodiment of the present invention is a light-emitting device having an organic compound represented by the structural formula (100), the structural formula (101), the structural formula (102), the structural formula (123), or the structural formula (150).

[0039] [ka]

[0040] Another embodiment of the present invention is an electronic device including any of the above light-emitting devices, a sensor, an operation button, and a speaker or a microphone.

[0041] Another embodiment of the present invention is a light-emitting device including any of the above light-emitting devices and a transistor or a substrate.

[0042] Another embodiment of the present invention is a display device including any of the above light-emitting devices and a transistor or a substrate.

[0043] Another embodiment of the present invention is a lighting device including any of the above light-emitting devices and a housing.

[0044] In this specification, the term "light-emitting device" includes an image display device using a light-emitting device. The term "light-emitting device" may also include a module in which a connector, such as an anisotropic conductive film or TCP (Tape Carrier Package), is attached to a light-emitting device, a module in which a printed wiring board is provided at the end of the TCP, or a module in which an IC (integrated circuit) is directly mounted on a light-emitting device using a COG (Chip On Glass) method. Furthermore, lighting fixtures and the like may include a light-emitting device.

[0045] Furthermore, the electronic device in this specification includes a light-emitting device, a light-receiving device (sensor, solar cell, etc.), or a device that combines a light-emitting device and a light-receiving device.

[0046] The term "light-emitting device," "electronic device," or "organic device" as used herein also includes layers or structures provided outside the space between a pair of electrodes, such as a partition wall, a sealing film, or a color filter provided on the electrodes. [Effects of the Invention]

[0047] According to one embodiment of the present invention, a light-emitting device with high emission efficiency or a light-emitting device, a light-emitting apparatus, an electronic device, a display device, or an electronic device with low power consumption can be provided.

[0048] Note that the description of these effects does not preclude the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. Note that effects other than these will become apparent from the description in the specification, drawings, claims, etc., and it is possible to extract other effects from the description in the specification, drawings, claims, etc. [Brief explanation of the drawings]

[0049] [Figure 1] 1A to 1E are diagrams illustrating the configuration of a light-emitting device according to an embodiment. [Figure 2] 2A and 2B are a top view and a cross-sectional view of the light-emitting device. [Figure 3] 3A to 3D are cross-sectional views showing a light-emitting device. [Figure 4] 4A to 4E are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 5] 5A to 5E are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 6] 6A to 6C are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 7] 7A to 7C are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 8] 8A to 8C are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 9] 9A to 9C are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 10] 10A to 10C are cross-sectional views showing an example of a method for manufacturing a light-emitting device. [Figure 11] 11A to 11G are top views showing examples of pixel configurations. [Figure 12] 12A to 12I are top views showing examples of pixel configurations. [Figure 13]13A and 13B are perspective views showing configuration examples of a display module. [Figure 14] 14(A) and 14(B) are cross-sectional views showing examples of the configuration of a light-emitting device. [Figure 15] FIG. 15 is a perspective view showing an example of the configuration of a light emitting device. [Figure 16] Fig. 16A is a cross-sectional view showing a structural example of a light-emitting device, Fig. 16B and Fig. 16C are cross-sectional views showing structural examples of a transistor. [Figure 17] FIG. 17 is a cross-sectional view showing an example of the configuration of a light emitting device. [Figure 18] 18A to 18D are cross-sectional views showing examples of the configuration of a light-emitting device. [Figure 19] 19A to 19D are diagrams showing examples of electronic devices. [Figure 20] 20A to 20F are diagrams showing examples of electronic devices. [Figure 21] 21A to 21G are diagrams showing examples of electronic devices. [Figure 22] Figure 22 shows the 1H NMR spectrum of the organic compound. [Figure 23] FIG. 23 is a diagram illustrating the absorption spectrum and emission spectrum of an organic compound in a toluene solution. [Figure 24] FIG. 24 is a diagram illustrating the absorption spectrum and emission spectrum of a solid thin film of an organic compound. [Figure 25] FIG. 25 shows the 1H NMR spectrum of an organic compound. [Figure 26] FIG. 26 is a diagram illustrating the absorption spectrum and emission spectrum of an organic compound in a toluene solution. [Figure 27] FIG. 27 is a diagram illustrating the absorption spectrum and emission spectrum of a solid thin film of an organic compound. [Figure 28] FIG. 28 shows the 1H NMR spectrum of an organic compound. [Figure 29]FIG. 29 is a diagram illustrating the absorption spectrum and emission spectrum of an organic compound in a toluene solution. [Figure 30] FIG. 30 is a diagram illustrating the absorption spectrum and emission spectrum of a solid thin film of an organic compound. [Figure 31] FIG. 31 is a diagram illustrating the results of measuring the refractive index and extinction coefficient of each organic compound. [Figure 32] FIG. 32 is a diagram illustrating the results of measuring the refractive index and extinction coefficient of each organic compound. [Figure 33] FIG. 33 is a diagram illustrating the results of measuring the refractive index and extinction coefficient of each organic compound. [Figure 34] FIG. 34 is a diagram illustrating the results of measuring the refractive index and extinction coefficient of each organic compound. [Figure 35] FIG. 35 is a diagram illustrating the results of measuring the refractive index and extinction coefficient of each organic compound. [Figure 36] FIG. 36 is a diagram illustrating the structure of the sample. [Figure 37] FIG. 37 is a graph showing the luminance-voltage characteristics of the sample. [Figure 38] FIG. 38 is a graph showing the current density-voltage characteristics of the sample. [Figure 39] FIG. 39 is a graph showing the current efficiency-luminance characteristics of the sample. [Figure 40] FIG. 40 is a graph showing the power efficiency-luminance characteristics of the sample. [Figure 41] FIG. 41 is a diagram showing the BI-brightness characteristics of the sample. [Figure 42] FIG. 42 shows the electroluminescence spectrum of the sample. [Figure 43] FIG. 43 shows the change in normalized brightness of the sample over time. [Figure 44] FIG. 44 is a diagram showing the luminance-voltage characteristics of the sample. [Figure 45] FIG. 45 is a graph showing the current density-voltage characteristics of the sample. [Figure 46] FIG. 46 is a graph showing the current efficiency-luminance characteristics of the sample. [Figure 47] FIG. 47 is a graph showing the power efficiency-luminance characteristics of the sample. [Figure 48] FIG. 48 shows the BI-brightness characteristics of the sample. [Figure 49] FIG. 49 shows the electroluminescence spectrum of the sample. [Figure 50] FIG. 50 shows the change in normalized brightness of the sample over time. [Figure 51] FIG. 51 is a diagram showing the luminance-voltage characteristics of the sample. [Figure 52] FIG. 52 is a graph showing the current density-voltage characteristics of the sample. [Figure 53] FIG. 53 is a graph showing the current efficiency-luminance characteristics of the sample. [Figure 54] FIG. 54 is a graph showing the power efficiency-luminance characteristics of the sample. [Figure 55] FIG. 55 is a diagram showing the BI-brightness characteristics of the sample. [Figure 56] FIG. 56 shows the electroluminescence spectrum of the sample. [Figure 57] Figure 57 shows the 1H NMR spectrum of an organic compound. [Figure 58] FIG. 58 is a diagram illustrating the absorption spectrum and emission spectrum of an organic compound in a toluene solution. [Figure 59] FIG. 59 is a diagram illustrating the absorption spectrum and emission spectrum of a solid thin film of an organic compound. [Figure 60] Figure 60 is a 1H NMR spectrum of an organic compound. [Figure 61] FIG. 61 is a diagram illustrating the absorption spectrum and emission spectrum of an organic compound in a toluene solution. [Figure 62] FIG. 62 is a diagram illustrating the absorption spectrum and emission spectrum of a solid thin film of an organic compound. DETAILED DESCRIPTION OF THE INVENTION

[0050] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be readily understood by those skilled in the art that various changes in form and details can be made without departing from the spirit and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the description of the embodiments shown below.

[0051] When light is incident on a material with optical anisotropy, the light in the vibration plane parallel to the optical axis is called extraordinary light (extraordinary ray), and the light in the vibration plane perpendicular to the optical axis is called ordinary light (ordinary ray). However, the refractive index of the material for ordinary light and extraordinary light may differ. In such cases, anisotropy analysis can be performed to separate the ordinary and extraordinary refractive indices and calculate each refractive index. In this specification, if the measured material has both an ordinary refractive index and an extraordinary refractive index, the ordinary refractive index will be used as the index. Furthermore, when simply referring to the refractive index, it will refer to the average value of the ordinary and extraordinary refractive indices.

[0052] Similarly to the refractive index, the extinction coefficient may have different values ​​for ordinary and extraordinary light, and by performing anisotropy analysis, it is possible to separate the ordinary and extraordinary light extinction coefficients and calculate each extinction coefficient separately. In this specification, when the measured material has both an ordinary light extinction coefficient and an extraordinary light extinction coefficient, the ordinary light extinction coefficient is used as the index, and when simply referring to the extinction coefficient, it refers to the average value of the ordinary light extinction coefficient and the extraordinary light extinction coefficient.

[0053] In addition, the vapor-deposited film in this specification refers to a film formed by vapor deposition on a substrate at room temperature or in a state where the substrate is not heated.

[0054] (Embodiment 1) In this embodiment, an organic compound which is one embodiment of the present invention will be described.

[0055] Specifically, the organic compound described in this embodiment is a compound having a carbazole ring (also referred to as a carbazole compound). In particular, the organic compound is an organic compound having a carbazole ring and a phenanthrene ring. In particular, the organic compound is an organic compound having a carbazole ring and two to four naphthalene rings.

[0056] The organic compound of one embodiment of the present invention has one to three phenanthrene rings or two to four naphthalene rings as substituents on the carbazole ring, thereby achieving a high refractive index, a low sublimation temperature (or deposition temperature), and being less susceptible to thermal decomposition during sublimation. From the viewpoint of the sublimation temperature, the number of naphthalene rings is more preferably two to three.

[0057] In addition, it is useful for organic compounds used in industrial products to have a low deposition temperature. In other words, since films can be formed at low temperatures, the organic compounds are less susceptible to the heat they receive during film formation, and thermal decomposition can be reduced.

[0058] In particular, in mass production processes, the same material is heated continuously for long periods of time, and organic compounds with high deposition temperatures are prone to decomposition. Decomposition of the material leads to a deterioration in the vacuum level of the deposition atmosphere, further increases in the deposition temperature, and a decrease in the luminescence efficiency or reliability of the fabricated elements that absorb light in the visible range of the deposited film, making it impossible to maintain a stable mass production system. Therefore, organic compound materials that can be formed into films at low temperatures can be formed without decomposition, enabling stable mass production.

[0059] Specifically, the organic compound of one embodiment of the present invention is preferably deposited in a deposition apparatus at a temperature of 350° C. or lower, preferably 330° C. or lower, more preferably 300° C. or lower, and further preferably 270° C. or lower. Here, the deposition temperature is defined as the temperature at which the pressure of the deposition apparatus is 1.0×10 -6 Pa or more 1.0×10 -4 At any pressure less than 1×10 Pa, the deposition rate is 1×10 -1 The evaporation source temperature was defined as the evaporation rate of 1×10-1 nm / s is 1 x 10 per second -1 This represents the deposition rate of nanometers, and the higher the deposition rate, the faster the film can be deposited. In mass production processes, shortening the takt time is required to reduce production costs, so high-speed film deposition is preferred.

[0060] The sublimation temperature of the organic compound according to one embodiment of the present invention is 350° C. or lower, preferably 300° C. or lower, more preferably 290° C. or lower, and even more preferably 260° C. or lower. The sublimation temperature can be evaluated by measurement using a thermogravimetry-differential thermal analyzer (TG-DTA). For example, the pressure of the TG-DTA measurement device can be set to 1.0×10 -1 When the pressure is controlled to between 10 Pa and 10 Pa, the measured weight of the compound used in the measurement is between 1 mg and 20 mg, and the sublimation temperature is the temperature at which the weight determined by thermogravimetry is -5% of the weight at the start of the measurement (referred to as the 5% weight loss temperature).

[0061] In addition, in measurements using a TG-DTA apparatus, it is also preferable that the temperature at which the weight is 50% less than that at the start of the measurement (referred to as the 50% weight loss temperature) is low. A low 50% weight loss temperature means that the compound can be stably sublimated at a low temperature even if the sublimation weight increases. The 50% weight loss temperature of the organic compound of one embodiment of the present invention is preferably 390°C or lower, preferably 350°C or lower, more preferably 320°C or lower, and even more preferably 300°C or lower.

[0062] Furthermore, the organic compound of one embodiment of the present invention can increase the refractive index of a formed film. First, since the organic compound has a carbazole skeleton, the refractive index can be increased and the anisotropy of the refractive index can be increased compared to a film not having such a skeleton.

[0063] Furthermore, the refractive index can be further increased by including a fused ring within the molecule. For example, it is preferable to include a phenanthrene ring or a naphthalene ring. These rings are preferably bonded to a carbazole ring as a substituent, because they have a small molecular weight, can be sublimated at low temperatures, and provide high heat resistance and an improved refractive index. Although the presence of at least one phenanthrene ring or naphthalene ring within a molecule can provide a compound with a high refractive index, the presence of two or more phenanthrene rings can further increase the refractive index. For example, a binaphthalene structure in which two naphthalene rings are directly linked is preferable. Furthermore, the presence of a binaphthalene structure as a substituent can increase the glass transition temperature (Tg) of the compound. Furthermore, the refractive index can be further increased by including a structure in which the 2-position of naphthalene is bonded to another group (i.e., a 2-naphthyl group). This is because the density of the organic compound in the formed film is increased. In particular, the refractive index can be further increased by including a 2,2'-binaphthalene structure in which the 2-positions of naphthalene are bonded to each other as a partial structure. However, without being limited thereto, for example, when the 1-position of naphthalene contains a structure bonded to another group (ie, when a 1-naphthyl group is contained), Tg can be improved.

[0064] Since an increase in the number of condensed rings may increase the deposition temperature, the number of naphthalene rings is preferably 4 or less, and more preferably 3 or less.

[0065] Furthermore, when benzene is used as a substituent, it is preferable that the compound has paraphenylene (also called p-phenylene).Compared to compounds having metaphenylene (or orthophenylene), compounds having paraphenylene have higher molecular orientation when formed into a film, and can improve the ordinary light refractive index.However, metaphenylene or orthophenylene can also be used, and in that case, the effect of lowering the sublimation temperature and the effect of suppressing the crystallization of the film can be expected.

[0066] Regarding the refractive index, for example, the ordinary light refractive index no at a wavelength of 450 nm, which is in the blue wavelength region, is preferably 1.9 or more. The ordinary light extinction coefficient k is preferably 0.2 or less, and more preferably 1×10 -2 or less, more preferably 1 × 10 -4 Furthermore, the organic compound of one embodiment of the present invention has an ordinary refractive index (n o ) and extraordinary refractive index (n e ) and the difference (Δn = |n o -n e The refractive index is an organic compound in which the refractive index | is 0.1 or more and 0.4 or less. Details of the refractive index values ​​will be shown in the second embodiment and examples.

[0067] Here, the ordinary refractive index (n o ) and extraordinary refractive index (n e ) difference (Δn=|n o -n e Δn can be used as an index of refractive index anisotropy. In the visible light range (360 nm to 830 nm), the larger Δn is, the greater the refractive index anisotropy tends to be.

[0068] For example, when an organic compound with a high refractive index anisotropy is used in any structure of a light-emitting device, light emitted from the light-emitting layer can be extracted with high efficiency, and the light extraction efficiency can be increased, which is useful.

[0069] The carbazole compound according to one embodiment of the present invention may have a heterocycle as a substituent. Examples of heteroatoms (also referred to as heteroatoms) included in the heterocycle include nitrogen, oxygen, and sulfur. The presence of a heteroatom may increase the ordinary refractive index (n) or the glass transition temperature (Tg). To improve the refractive index, the heterocycle preferably includes a five-membered heteroaromatic ring skeleton containing nitrogen, oxygen, or sulfur. For example, heterocycles including a pyrrole skeleton, a furan skeleton, a thiophene skeleton, or an azole (e.g., imidazole, oxazole, thiazole, oxadiazole, or triazole) skeleton are preferred. In particular, compounds having an atom with a large atomic radius, such as sulfur, in their molecular structure are expected to have a high refractive index (e.g., Structural Formula (210), Structural Formula (226), and Structural Formula (227) described below). Furthermore, a structure in which the fused ring contains a heteroatom is preferable because the fused ring has the effect of improving Tg and the heteroatom has the effect of improving the refractive index at the same time (e.g., structural formula (209), structural formula (210), structural formula (222) to structural formula (229) described below). That is, a fused heteroaromatic ring having a five-membered ring containing nitrogen, oxygen, or sulfur is preferable, such as a carbazole ring, a dibenzofuran ring, a benzonaphthofuran ring, a dibenzothiophene ring, a benzonaphthothiophene ring, a benzoxazole ring, and a benzothiazole ring. However, depending on the type of heterocycle, the presence of a heteroatom may reduce solubility in organic solvents, which may lead to a decrease in reaction yield during synthesis and a decrease in purity during purification. Furthermore, the presence of a heterocycle in the molecular structure may strengthen intermolecular interactions, leading to an increase in the sublimation temperature. Therefore, the total number of heteroatoms contained in the compound other than the carbazole ring is preferably 3 or less, preferably 2 or less, and more preferably 1 or less. Alternatively, the total number of heterocyclic rings contained in the compound other than the carbazole ring is preferably 3 or less, more preferably 2 or less, and even more preferably 1 or less.

[0070] <Example of organic compound 1> One embodiment of the present invention is an organic compound represented by general formula (G1).

[0071] [ka]

[0072] However, in general formula (G1), R 1 ~R 4 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-1), and R 5 ~R 8 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-3), and R 5 ~R 8 At least one of the groups is a substituent represented by the following general formula (G1-3), and Ar 11 represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 12 represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms. n11 represents an integer of 0 to 3, and n12 represents an integer of 1 to 3.

[0073] [ka]

[0074] However, in the general formula (G1-1) and the general formula (G1-3), Ar 13 , Ar 15 , and Ar 16each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms (also referred to as an arylene group) or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms (also referred to as a heteroarylene group); Ar 14 and Ar 17 each independently represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent aromatic heterocyclic group (also referred to as an aryl group) having 3 to 30 carbon atoms; Ar 15 , Ar 16 and Ar 17 At least two of n13 represent a bicyclic or tricyclic monovalent or divalent aromatic hydrocarbon group, or a monovalent or divalent aromatic heterocyclic group (also referred to as a heteroaryl group). n13 represents an integer of 0 to 3, and n14, n15, n16, and n17 each independently represent an integer of 1 to 3. n15 + n16 + n17 > n13 + n14.

[0075] In addition, when n11 is 2 or more, multiple Ar 11 may be the same or different substituents. 12 ~Ar 17 The same applies when there are multiple Ar 11 ~Ar 17 Preferably, Ar represents a substituent consisting of carbon and hydrogen (including deuterium). 12 , Ar 14 , Ar 17 may be hydrogen (deuterium).

[0076] In the above general formula (G1), R 1 ~R 4 Among the substituents, those other than those represented by general formula (G1-1), or R 5 ~R 8 Among these, it is preferable that the substituents other than those represented by the general formula (G1-3) are hydrogen atoms, since the molecular structure becomes more rigid than when the substituents are other than hydrogen atoms, the intermolecular interaction becomes stronger, and the refractive index can be increased. Furthermore, it is also preferable because the synthesis cost can be reduced.

[0077] In addition, in the general formula (G1), R 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 4 and R 5 , R 5 and R 6 , R 6 and R 7 , and R 7 and R 8 For example, R 2 and R 3 When a benzene ring containing the carbazole ring is formed, the benzene ring and the carbazole ring are condensed to form a structure containing a benzocarbazole ring. By forming such a condensed structure, the heat resistance and glass transition temperature (Tg) can be improved. On the other hand, when such a condensed structure is not formed, the molecular weight is reduced and the sublimation temperature can be reduced.

[0078] Here, when the general formula (G1) contains a naphthalene ring or a naphthalene skeleton, the ordinary light refractive index can be increased. In this specification, unless otherwise specified, a compound having a naphthalene ring refers to a compound having a naphthalene ring itself, such as the structure (100) shown later, and does not include a compound having naphthalene as part of the ring, such as the structure (102) shown later. Furthermore, a compound having a naphthalene skeleton includes a compound having naphthalene as part of the skeleton, such as the structure (102). This is not limited to naphthalene, and other rings or skeletons can also be interpreted in the same way.

[0079] Furthermore, by bonding the 2-positions of the naphthalene skeleton together, the ordinary light refractive index can be further increased. Alternatively, by not having a bond at the 1-position of the naphthalene skeleton, the refractive index can be increased. Furthermore, by using fused rings with three or fewer rings, the sublimation temperature can be lowered. Note that a fused ring with two rings refers to those with two rings, such as naphthalene, quinoxaline, or benzoxazole, and a fused ring with three rings refers to those with three rings, such as phenanthrene, anthracene, or carbazole. The same applies to those with four or more rings.

[0080] For example, Ar 15 , Ar 16 and Ar 17 At least two of the Ar are preferably substituents containing a substituted or unsubstituted naphthalene ring. 16 and Ar 17 is preferably a substituent containing a naphthalene ring. 16 and Ar 17 In the case of naphthalene, it is preferable that each naphthalene is bonded to the 2-position. 16 and Ar 17 is naphthalene, it is preferable that each naphthalene is bonded to the 2-position of the other naphthalene and has 2,2'-binaphthalene in the partial structure (for example, the following structural formula (100)).

[0081] In addition, it is preferable that naphthalene is bonded to another group at least at the 2-position. 15 is naphthalene, at least at positions 2 and 6, a carbazolyl group and Ar 16 It is good to bond with Ar. 16 If naphthalene, Ar 15 and Ar 17 It is good to bond with Ar. 17 In the case of naphthalene, Ar is at the second position. 16 It is good to combine with

[0082] In particular, Ar 15 , and Ar 16 Ar is ranked 6th in the list.16 and Ar 17 When these two bond, a material with a high refractive index for ordinary light can be provided. By using this material in a device, a highly efficient device can be realized, and a device with low power consumption can be achieved. In addition, a material with high heat resistance can be provided. By using this material in a device, a highly efficient and highly heat-resistant device can be provided.

[0083] In addition, in the organic compound example 1, n15+n16+n17>n13+n14. In this way, when the number of substituents bonded to one of the two benzene rings of the carbazole ring is made larger than the number of substituents bonded to the other, the anisotropy of the refractive index tends to increase, which is preferable. In addition, in the organic compound example 1, the number of arylene groups or heteroarylene groups connected to one of the two benzene rings of the carbazole ring (Ar 15 ~Ar 17 The number of arylene groups or heteroarylene groups connected to the other substituent (Ar 13 and Ar 14 When n is larger than the number of bonds (n), the anisotropy of the refractive index tends to increase, which is preferable. In addition, it is considered that the intermolecular interaction is reduced, which is preferable because it becomes possible to reduce the sublimation temperature. Furthermore, in the above Example 1, when n15+n16+n17>n11+n12, the anisotropy of the refractive index tends to increase, which is preferable. Furthermore, by setting such a relationship of n, it is possible to increase Tg.

[0084] <Example of organic compound 2> One embodiment of the present invention is an organic compound represented by general formula (G1).

[0085] [ka]

[0086] However, in general formula (G1), R 1 ~R4 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-1), and R 5 ~R 8 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-2), and R 5 ~R 8 At least one of the groups is a substituent represented by the following general formula (G1-2), and Ar 11 represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 12 represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 14 to 30 carbon atoms or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms. n11 represents an integer of 0 to 3, and n12 represents an integer of 1 to 3.

[0087] [ka]

[0088] However, in the general formula (G1-1) and the general formula (G1-2), Ar 13 , and Ar 15 each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 14 and Ar 17 each independently represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 15 , or Ar 17At least one of the groups is phenanthrene, and Ar 17 When n13 is phenanthrene, it is bonded to another group at the 2nd or 3rd position of the phenanthrene. n13 represents an integer of 0 to 3, and n14, n15, and n17 each independently represent an integer of 1 to 3. n15 + n17 > n13 + n14.

[0089] Also, Ar 12 and Ar 17 may each be a condensed ring of two or more rings, preferably three or more rings.

[0090] Also, Ar 15 , and Ar 17 At least one of the rings is preferably a fused ring of two or more rings, preferably three or more rings, and more preferably four or more rings. An example of a fused ring of four or more rings is a triphenylene ring. The use of a triphenylene ring is preferable because it increases the refractive index and Tg. When the sublimation temperature is low, it is preferable that the number of rings is small, and n15 may be 0.

[0091] In addition, in the general formula (G1-1) and the general formula (G1-2), Ar 11 , or Ar 12 At least one of Ar represents a fused ring; 15 , or Ar 17 At least one of n11, n12, n15 and n17 independently represents an integer of 1 to 3.

[0092] In addition, when n15 is 2 or more, multiple Ar 15 may be the same or different substituents. 17 The same applies when there are multiple Ar 15 and Ar 17 Preferably, Ar represents a substituent consisting of carbon and hydrogen (including deuterium). 12 , Ar 14 , Ar 17 may be hydrogen (deuterium).

[0093] In the general formula (G1-2), Ar 15 , or Ar 17 is phenanthrene, and the phenanthrene can be bonded to other groups at the 2- or 3-position to increase the ordinary refractive index. 17 When the compound is phenanthrene, the refractive index for ordinary light can be further increased by bonding to another group at the 2nd or 3rd position of the phenanthrene (for example, the following structural formula (103)).

[0094] In addition, in the organic compound example 2, n15+n17>n13+n14. In this way, when the number of substituents bonded to one of the two benzene rings of the carbazole ring is made larger than the number of substituents bonded to the other, the anisotropy of the refractive index tends to increase, which is preferable. In addition, in the organic compound example 2, the number of arylene groups or heteroarylene groups connected to one of the two benzene rings of the carbazole ring (Ar 15 and Ar 17 The number of arylene groups or heteroarylene groups connected to the other substituent (Ar 13 and Ar 14 When n15+n17>n11+n12 in the above Example 2, the anisotropy of the refractive index tends to increase, which is preferable. Furthermore, it is considered that the intermolecular interaction is reduced, which makes it possible to reduce the sublimation temperature, which is preferable. Furthermore, when n15+n17>n11+n12 in the above Example 2, the anisotropy of the refractive index tends to increase, which is preferable. Furthermore, by making the relationship of n like this, it is possible to increase Tg.

[0095] <Substituents for each organic compound example> In addition, R in the general formula (G1), the general formula (G1-1), the general formula (G1-2), and the general formula (G1-3) described in <Example 1 of the organic compound> and <Example 2 of the organic compound> 1 ~R 8 , Ar 11 ~Ar 15, and Ar 17 is the R described in <Example 1 of Organic Compound> or <Example 2 of Organic Compound>. m (m is any number), or Ar m (m is any number) can be taken into consideration.

[0096] In addition, in general formula (G1), R 1 ~R 8 When the alkyl group having 1 to 6 carbon atoms is an alkyl group having 1 to 6 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a sec-pentyl group, a tert-pentyl group, a neopentyl group, a hexyl group, an isohexyl group, a 3-methylpentyl group, a 2-methylpentyl group, a 2-ethylbutyl group, a 1,2-dimethylbutyl group, a 2,3-dimethylbutyl group, etc. When the alkyl group having 1 to 6 carbon atoms has a substituent, the substituent can be a cycloalkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 13 carbon atoms.

[0097] In general formula (G1), R 1 ~R 8 In the case of a cycloalkyl group having 3 to 6 carbon atoms, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a 1-methylcyclohexyl group, a cycloheptyl group, an adamantyl group, a bicyclo[2,2,2]octyl group, a norbornanyl group, etc. In the case where the cycloalkyl group having 3 to 6 carbon atoms has a substituent, examples of the substituent include a cycloalkyl group having 1 to 4 carbon atoms and an aryl group having 6 to 13 carbon atoms.

[0098] R in any one of the general formulae (G1), (G1-1) to (G1-3) 1 ~R 8 , Ar 11 ~Ar 17is an aromatic hydrocarbon group having 6 to 30 carbon atoms or an aromatic heterocyclic group having 3 to 30 carbon atoms, a group having a structure in which n hydrogen atoms have been removed from an aromatic hydrocarbon group or an aromatic heterocyclic ring represented by any of the following structural formulas (Ar-1) to (Ar-33) can be used.

[0099] For example, a naphthyl group refers to a monovalent substituent obtained by removing one hydrogen atom from naphthalene (shown in the following structural formula (Ar-17)). Also, a naphthalenyl group refers to a divalent substituent obtained by removing two hydrogen atoms from naphthalene. The same applies to other structural formulas (Ar-1) to (Ar-33). Therefore, for example, in the above general formula (G1-3), Ar 15 is pyridine (represented by the following structural formula (Ar-5)), Ar 16 is naphthalene, Ar 17 is naphthalene, strictly speaking, 15 is a pyridinyl group, Ar 16 is a naphthalenyl group, Ar 17 is a naphthyl group, but for simplicity it is expressed as "Ar 15 is pyridine, and Ar 16 and Ar 17 is naphthalene." Structural formula (100) and structural formula (101) can also be written as "a compound containing multiple naphthalene rings" or "a compound containing multiple naphthalenes." In addition, the valence, such as monovalent or divalent, can be omitted.

[0100] [ka]

[0101] Furthermore, when the aromatic hydrocarbon group or aromatic heterocyclic group has a substituent, the substituent can be a cyano group, a halogen group, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, an aryl group having 6 to 13 carbon atoms, or a heteroaryl group having 3 to 10 carbon atoms. The presence of a cyano group or a halogen group is expected to have the effect of reducing the driving voltage of the device. Furthermore, the presence of an alkyl group or a cycloalkyl group is expected to have the effect of reducing the sublimation temperature, making it possible to apply the compound to various layers, including the cap layer. Furthermore, the presence of an alkyl group or a cycloalkyl group may reduce the ordinary refractive index, making it particularly suitable for use in layers that require a small ordinary refractive index, such as a transport layer (hole transport layer or electron transport layer). Note that R 1 ~R 8 The same effect can be expected when a cyano group, a halogen group, an alkyl group, or a cycloalkyl group is used as the alkyl group.

[0102] <Example> Next, specific examples of the organic compound having the structure represented by General Formula (G1) above, which is one embodiment of the present invention, are shown below.

[0103] [ka]

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109] [ka]

[0110] [ka]

[0111] [ka]

[0112] [ka]

[0113] [ka]

[0114] [ka]

[0115] [ka]

[0116] The organic compounds represented by the general formula (G1), the general formula (G1-1), the general formula (G1-2), the general formula (G1-3), and the structural formulas (100) to (239) are examples, and the organic compounds of one embodiment of the present invention are not limited to these.

[0117] <Method for synthesizing organic compounds> A method for synthesizing the organic compound represented by general formula (G1) described above in <Example 1 of Organic Compound> will be described. In the general formula (G1), general formula (G1-1), general formula (G1-2), and general formula (G1-3) shown below, R 1 ~R 8 , Ar 11 ~Ar 17 , n11 to n17 can appropriately adopt the above-mentioned configurations.

[0118] [ka]

[0119] Here, general formula (G1) can be represented by general formula (G1a) or general formula (G1b) shown below. General formula (G1a) is a general formula (G1a) in which R 1 ~R 4 one of which is bonded to general formula (G1-1), and the other is R 11 ~R 13 is replaced by R 5 ~R 8 one of which is bonded to general formula (G1-2), and the other is R 14 ~R 16 The same applies to general formula (G1b), which shows a structure in which general formula (G1-1) and general formula (G1-3) are bonded to general formula (G1), and R 11 ~R 16 The structure shown is substituted with R 11 ~R 16 is the above-mentioned R 1 ~R 8 can be appropriately adopted. 1 ~R 4 Examples of general formula (G1-1) bonded to any one of R 1 ~R 4 may all be hydrogen (including deuterium).

[0120] [ka]

[0121] <Method for synthesizing organic compound represented by general formula (G1a)> Various reactions can be applied to synthesize the organic compound represented by the general formula (G1a) above. For example, the organic compound represented by the general formula (G1a) can be synthesized by a simple method shown in the following synthesis scheme.

[0122] As shown in the following scheme (Sa-1), a carbazole compound represented by general formula (G1a) is obtained by coupling compound 1, which is a compound containing a carbazole skeleton (also called a carbazole compound), with compound 2. 1 is bonded to one carbon atom of the benzene ring and represents a boronic acid, a boronic acid ester, a cyclic triol borate salt, or the like (also called boronic acid, etc.). Note that the cyclic triol borate salt may be a potassium salt or a sodium salt in addition to a lithium salt. In Compound 2, X 1 represents a halogen. For example, the Suzuki-Miyaura reaction using a palladium catalyst can be used as a coupling reaction.

[0123] In addition, B of Compound 1 1 X 1 In this case, X of compound 2 may be 1 B 1 It is good to use R 14 ~R 16 may have boronic acid or the like at two of the positions. In that case, compound 2 can be bound to the two positions.

[0124] [ka]

[0125] <Method for synthesizing organic compound represented by general formula (G1b)> An example of a method for synthesizing the organic compound represented by the above general formula (G1b) will be shown below.

[0126] First, as shown in the following scheme (Sb-1), compound 3 and compound 4 are coupled to obtain compound 5. In compound 3, B 2 represents boronic acid, etc. In Compound 4 and Compound 5, X 2 , X 3 represents a halogen. 2 , X 3 may be the same halogen element or different halogen elements. 2 is iodine, X 3 is bromine), this is preferred because the coupling reaction based on one of the halogen atoms proceeds selectively.

[0127] [ka]

[0128] The obtained compound 5 can be used in place of compound 2 in the above scheme (Sa-1). In this case, an organic compound represented by general formula (G1b) can be obtained by a coupling reaction between compound 1 and compound 5.

[0129] <Other Methods for Synthesizing Organic Compounds Represented by General Formula (G1a) or General Formula (G1b)> Regarding the synthesis method of the organic compound represented by the general formula (G1a) or (G1b), an example different from the above will be shown below.

[0130] The organic compound represented by the general formula (G1a) can be synthesized using the following synthesis scheme (Sa-2) and synthesis scheme (Sa-3).

[0131] Compound 6 is a 9H-carbazole compound in which nitrogen and hydrogen are bonded. As shown in synthetic scheme (Sa-2), compound 6 is coupled with compound 2 to obtain compound 7.

[0132] [ka]

[0133] Next, as shown in the synthetic scheme (Sa-3), compound 7 and compound 8 are coupled to obtain the organic compound represented by general formula (G1a). For example, the Buchwald-Hartwig reaction using a palladium catalyst can be used as the coupling reaction.

[0134] [ka]

[0135] Although the above example shows the use of compound 7 as an intermediate, a device may be manufactured using compound 7, not just as an intermediate. In addition, hydrogen in compounds 6 and 7 includes deuterium.

[0136] Furthermore, by using compound 5 instead of compound 2 in synthesis scheme (Sa-2), an organic compound represented by general formula (G1b) can be obtained.

[0137] In addition, the above-mentioned compound 2 and compound 8 may be the same compound. Using the same compound may enable simultaneous performance of synthetic scheme (Sa-2) and synthetic scheme (Sa-3), which is preferable because it reduces the number of steps.

[0138] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0139] (Embodiment 2) In this embodiment mode, a structure of a light-emitting device using the organic compound described in Embodiment Mode 1 will be described with reference to FIGS.

[0140] <Basic structure of light-emitting devices> The basic structure of a light-emitting device will be described. Fig. 1A shows a light-emitting device having a structure (single structure) in which an organic compound layer including a light-emitting layer is disposed between a pair of electrodes. Specifically, the light-emitting device shown in Fig. 1A has a first electrode 101, a second electrode 102, an organic compound layer 103, and a cap layer 107.

[0141] Specifically, an organic compound layer 103 is provided on a first electrode 101, a second electrode 102 is provided on the organic compound layer 103, and a cap layer 107 is provided on the second electrode 102 in this order. Here, the second electrode 102 is a light-transmitting electrode, and the light-emitting device has a structure in which light is emitted from the second electrode 102 side.

[0142] 1B shows a light-emitting device having a stacked structure (tandem structure) in which organic compound layers 103 (organic compound layers 103a and 103b) each having a plurality of layers (two layers in FIG. 1B) containing a light-emitting substance are disposed between a pair of electrodes, and a charge generation layer 106 is disposed between the organic compound layers 103. A light-emitting device with a tandem structure can realize a highly efficient light-emitting device without changing the amount of current.

[0143] The charge generation layer 106 has a function of injecting electrons into one organic compound layer (the organic compound layer 103a or the organic compound layer 103b) and injecting holes into the other organic compound layer (the organic compound layer 103b or the organic compound layer 103a) when a potential difference is generated between the first electrode 101 and the second electrode 102. Therefore, in FIG. 1B, when a voltage is applied to the first electrode 101 so that the potential thereof is higher than that of the second electrode 102, electrons are injected from the charge generation layer 106 into the organic compound layer 103a and holes are injected into the organic compound layer 103b.

[0144] From the viewpoint of light extraction efficiency, the charge generation layer 106 preferably has transparency to visible light (specifically, the transmittance of the charge generation layer 106 to visible light is 40% or more). Furthermore, even if the charge generation layer 106 has lower conductivity than the first electrode 101 and the second electrode 102, it can still function as a charge generation layer.

[0145] FIG. 1C also shows a stacked structure of an organic compound layer 103 of a light-emitting device according to one embodiment of the present invention. In this case, the first electrode 101 functions as an anode, and the second electrode 102 functions as a cathode. The organic compound layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are sequentially stacked over the first electrode 101. The light-emitting layer 113 may have a stacked structure of a plurality of light-emitting layers emitting different light colors. For example, a light-emitting layer containing a red light-emitting substance, a light-emitting layer containing a green light-emitting substance, and a light-emitting layer containing a blue light-emitting substance may be stacked, or a layer containing a carrier-transporting material may be interposed between the light-emitting layers. Alternatively, a light-emitting layer containing a yellow light-emitting substance and a light-emitting layer containing a blue light-emitting substance may be combined. However, the stacked structure of the light-emitting layer 113 is not limited to the above. For example, the light-emitting layer 113 may have a structure in which multiple light-emitting layers emitting the same light-emitting color are stacked. For example, a first light-emitting layer containing a blue light-emitting substance and a second light-emitting layer containing a blue light-emitting substance are stacked, or a layer containing a carrier-transporting material is interposed between the layers. A structure in which multiple light-emitting layers emitting the same light-emitting color are stacked may have higher reliability than a single-layer structure. Even in a tandem structure such as that shown in FIG. 1B, in which multiple EL layers are provided, each EL layer is stacked in order from the anode side as described above. When the first electrode 101 is a cathode and the second electrode 102 is an anode, the organic compound layer 103 is stacked in the reverse order. Specifically, the structure includes an electron injection layer 111, an electron transport layer 112, an emitting layer 113, a hole transport layer 114, and a hole injection layer 115 on the first electrode 101, which is a cathode.

[0146] The light-emitting layers 113 included in the organic compound layers (organic compound layer 103, organic compound layer 103a, organic compound layer 103b) each contain a light-emitting substance and a combination of multiple substances, and can be configured to emit fluorescent or phosphorescent light of a desired emission color. The light-emitting layer 113 may also have a stacked structure with different emission colors. In this case, different materials may be used as the light-emitting substance and other substances for each stacked light-emitting layer. Alternatively, a structure in which different emission colors are emitted from the multiple organic compound layers (organic compound layer 103a, organic compound layer 103b) shown in FIG. 1B may also be used. In this case, different materials may be used as the light-emitting substance and other substances for each light-emitting layer.

[0147] In addition, in a light-emitting device according to one embodiment of the present invention, for example, the first electrode 101 shown in FIG. 1C may be a reflective electrode, the second electrode 102 may be a semi-transmissive and semi-reflective electrode, and a micro-optical resonator (microcavity) structure may be formed. This allows light emitted from the light-emitting layer 113 included in the organic compound layer 103 to resonate between the two electrodes, thereby enhancing the intensity of light emitted from the second electrode 102. Therefore, high definition can be easily achieved. Furthermore, the intensity of light emitted from a specific wavelength in the front direction can be enhanced, thereby reducing power consumption.

[0148] When the first electrode 101 of the light-emitting device is a reflective electrode having a laminated structure of a reflective conductive material and a light-transmitting conductive material (transparent conductive film), optical adjustment can be performed by controlling the film thickness of the transparent conductive film. Specifically, it is preferable to adjust the optical distance (product of film thickness and refractive index) between the first electrode 101 and the second electrode 102 to mλ / 2 (where m is an integer of 1 or greater) or in the vicinity thereof, for the wavelength λ of light obtained from the light-emitting layer 113.

[0149] Furthermore, in order to amplify the desired light (wavelength: λ) obtained from the light-emitting layer 113, it is preferable to adjust the optical distance from the first electrode 101 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained and the optical distance from the second electrode 102 to the region (light-emitting region) in the light-emitting layer 113 where the desired light is obtained to be (2m'+1)λ / 4 (where m' is an integer of 1 or greater) or close to that. Note that the light-emitting region here refers to the recombination region of holes and electrons in the light-emitting layer 113.

[0150] By performing such optical adjustment, the spectrum of the specific monochromatic light obtained from the light-emitting layer 113 can be narrowed, and light emission with good color purity can be obtained.

[0151] In the above case, the optical distance between the first electrode 101 and the second electrode 102 can be strictly defined as the total thickness from the reflective region of the first electrode 101 to the reflective region of the second electrode 102. However, since it is difficult to precisely determine the reflective regions of the first electrode 101 and the second electrode 102, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 and the second electrode 102 as the reflective region. Furthermore, the optical distance between the first electrode 101 and the light-emitting layer from which desired light is obtained can be strictly defined as the optical distance between the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained. However, since it is difficult to precisely determine the reflective region of the first electrode 101 and the light-emitting region of the light-emitting layer from which desired light is obtained, the above-mentioned effect can be sufficiently achieved by assuming any position of the first electrode 101 as the reflective region and any position of the light-emitting layer from which desired light is obtained as the light-emitting region.

[0152] The light-emitting device shown in Figure 1(D) has a tandem structure. The tandem structure allows the device to emit light with high brightness. Furthermore, the tandem structure can reduce the current required to obtain the same brightness compared to a single structure, thereby improving reliability. Furthermore, power consumption can be reduced.

[0153] The light-emitting device shown in FIG. 1E is an example of the tandem-structure light-emitting device shown in FIG. 1B. As shown in the figure, the light-emitting device has a structure in which three organic compound layers (organic compound layer 103a, organic compound layer 103b, and organic compound layer 103c) are stacked with a charge generation layer (charge generation layer 106a and charge generation layer 106b) sandwiched between them. Note that the three organic compound layers (organic compound layer 103a, organic compound layer 103b, and organic compound layer 103c) each have a light-emitting layer (light-emitting layer 113a, light-emitting layer 113b, and light-emitting layer 113c), and the light-emitting colors of the light-emitting layers can be freely combined. For example, the light-emitting layer 113a can be blue, the light-emitting layer 113b can be red, green, or yellow, and the light-emitting layer 113c can be blue. Alternatively, the light-emitting layer 113a can be red, the light-emitting layer 113b can be blue, green, or yellow, and the light-emitting layer 113c can be red.

[0154] In the light-emitting device according to one embodiment of the present invention, the second electrode 102 is a light-transmitting electrode (such as a transparent electrode or a semi-transmitting / semi-reflective electrode). When the light-transmitting electrode is a transparent electrode, the visible light transmittance of the transparent electrode is 40% or more. When the semi-transmitting / semi-reflective electrode is used, the visible light reflectance of the semi-transmitting / semi-reflective electrode is 20% or more and 80% or less, preferably 40% or more and 70% or less. Furthermore, these electrodes have a resistivity of 1×10 -2 It is preferable to set it to Ωcm or less.

[0155] In the above-described light-emitting device according to one embodiment of the present invention, when the first electrode 101 is a reflective electrode (a reflective electrode), the reflectivity of the reflective electrode for visible light is set to 40% to 100%, preferably 70% to 100%. -2 It is preferable to set it to Ωcm or less.

[0156] <Specific structure of light-emitting device> Next, a specific structure of a light-emitting device according to one embodiment of the present invention will be described. Here, a tandem structure will be described with reference to FIG. 1D. The single-structure light-emitting devices shown in FIGS. 1A and 1C also have the same organic compound layer structure. When the light-emitting device shown in FIG. 1D has a microcavity structure, the first electrode 101 is formed as a reflective electrode, and the second electrode 102 is formed as a semi-transmissive and semi-reflective electrode. Therefore, a single or multiple desired electrode materials can be used to form a single layer or a stacked layer. The second electrode 102 is formed by selecting an appropriate material after the organic compound layer 103b is formed.

[0157] <Light-emitting device materials> Each component of the light-emitting device will be described below.

[0158] <Cap layer> The organic compound used in the cap layer 107 has a refractive index of ordinary light (n o ) is 1.90 or more, preferably 2.00 or more. o ) is 1.80 or more, preferably 1.9 or more. o ) is 1.75 or more, preferably 1.85 or more. о ) can prevent the light from the organic compound layer 103 from being totally reflected by the cap layer 107, thereby improving the light extraction efficiency.

[0159] In addition, the extraordinary refractive index at a wavelength of 450 nm (n e ) is 1.80 or less, preferably 1.70 or less. e ) is 1.70 or less, preferably 1.60 or less. e The extraordinary refractive index (n e ) tends to increase the anisotropy of the refractive index.

[0160] In addition, the ordinary refractive index (n o ) and extraordinary refractive index (n e ) and the difference (Δn = |n o -n e When Δn=|n o -n e is preferably 0.2 or more and 0.4 or less, and more preferably 0.3 or more and 0.4 or less.

[0161] Here, the ordinary refractive index (n o ) and the extraordinary refractive index (ne) (Δn = |n o -n e The refractive index (n |) can be used as an index of anisotropy in the refractive index. In the visible light range (360 nm or more and 830 nm or less), if Δn is large, the anisotropy of the refractive index also tends to be large. In order to increase Δn, о ) or by increasing the extraordinary refractive index (n e ) can be reduced.

[0162] By increasing the anisotropy of the refractive index in the cap layer 107, light emitted from the organic compound layer 103 can be extracted with high efficiency.

[0163] In addition, the cap layer 107 has an ordinary light extinction coefficient (k o ) is preferably small. Specifically, in the visible range (450 nm or more and 630 nm or less), it is 0.2 or less, preferably 1 × 10 -2 or less, more preferably 1 × 10 -4 When the ordinary light extinction coefficient is small, light emitted from the organic compound layer 103 can be extracted to the outside without being absorbed, making it possible to provide a highly efficient element.

[0164] In addition, considering the extraction efficiency, it is desirable that the ordinary extinction coefficient in the visible range be below the lower detection limit of the measuring device. On the other hand, if there is some absorption at wavelengths of 400 nm or less (if the ordinary extinction coefficient is not 0), ultraviolet light (light with a wavelength shorter than visible light) from outside the light-emitting device can be absorbed in the cap layer, potentially reducing damage caused by ultraviolet light to the structure below the cap layer. In this way, when considering ultraviolet absorption, it is desirable that the ordinary extinction coefficient at wavelengths of 400 nm or less be above the lower detection limit. For example, it is desirable that the ordinary extinction coefficient at 365 nm be 0.1 or more, more preferably 0.2 or more.

[0165] Examples of organic compounds that can be used as the cap layer 107 are shown below.

[0166] Applicable organic compounds include compounds having heterocycles. Examples of heteroatoms (also referred to as heteroatoms) contained in heterocycles include nitrogen, oxygen, and sulfur. The presence of heteroatoms can sometimes increase the ordinary refractive index (n) or the glass transition temperature (Tg). To improve the refractive index, the heterocycle preferably contains a five-membered heteroaromatic ring skeleton containing nitrogen, oxygen, or sulfur. For example, heterocycles containing a pyrrole skeleton, a furan skeleton, a thiophene skeleton, or an azole (e.g., imidazole, oxazole, thiazole, oxadiazole, or triazole) skeleton are preferred. Compounds with a molecular structure containing an atom with a large atomic radius, such as sulfur, are expected to have a high refractive index. Furthermore, a structure in which the fused ring contains a heteroatom is preferred because it simultaneously provides the effect of improving Tg through the fused ring and the effect of improving the refractive index through the heteroatom. That is, the heterocycle is preferably a fused heteroaromatic ring having a five-membered ring containing nitrogen, oxygen, and sulfur, such as a carbazole ring, a dibenzofuran ring, a benzonaphthofuran ring, a dibenzothiophene ring, a benzonaphthothiophene ring, a benzoxazole ring, and a benzothiazole ring. Therefore, in one embodiment of the present invention, an organic compound having the heterocycle and a phenanthrene ring described above is suitable for the capping layer 107. Furthermore, an organic compound having the heterocycle and two to four naphthalene rings described above is particularly suitable for the capping layer 107.

[0167] Applicable organic compounds include compounds having a carbazole ring (also called carbazole compounds), particularly organic compounds having a carbazole ring and a phenanthrene ring, and particularly organic compounds having a carbazole ring and two to four naphthalene rings.

[0168] The carbazole compound can increase the refractive index of the formed film, and since it has a carbazole skeleton, it can increase the refractive index and anisotropy compared to films that do not have this skeleton.

[0169] Furthermore, organic compounds suitable for the cap layer 107 can further increase their refractive index by including a fused ring in the molecule. For example, they preferably include a phenanthrene ring or a naphthalene ring. These rings are preferably bonded to a carbazole ring as a substituent. Although one phenanthrene ring or one naphthalene ring is sufficient in a molecule, including two or more can further increase the refractive index. For example, a binaphthalene structure in which two naphthalene rings are directly linked is preferred. Furthermore, including a binaphthalene structure as a substituent can increase the glass transition temperature (Tg) of the compound. Furthermore, including a structure in which the 2-position of naphthalene is bonded to another group (i.e., including a 2-naphthyl group) can further increase the refractive index. This is because the density of the organic compound in the formed film increases. In particular, including a 2,2'-binaphthalene structure in which the 2-positions of naphthalene are bonded to each other in a partial structure can further increase the refractive index. However, without being limited thereto, for example, when the 1-position of naphthalene contains a structure bonded to another group (ie, when a 1-naphthyl group is contained), Tg can be improved.

[0170] Since an increase in the number of fused rings may increase the deposition temperature, the number of naphthalene rings in the molecule is preferably 4 or less, more preferably 3 or less. From the viewpoint of increasing the refractive index, the number of naphthalene rings is preferably 2 or more.

[0171] Furthermore, when benzene is used as a substituent, it is preferable to use paraphenylene (also called p-phenylene).Compared to compounds having metaphenylene (or orthophenylene), compounds having paraphenylene have higher molecular orientation when formed into a film, and can improve the ordinary light refractive index.However, metaphenylene or orthophenylene can also be used, and in that case, the effect of reducing the sublimation temperature can be expected.

[0172] Preferably, the organic compound has one to three phenanthrene rings or two to four naphthalene rings as substituents on the carbazole ring, thereby realizing a high refractive index, having a low sublimation temperature (or vapor deposition temperature), and being less susceptible to thermal decomposition during sublimation. From the viewpoint of the sublimation temperature, the organic compound may have two to four, preferably two to three, naphthalene rings.

[0173] In addition, it is useful for organic compounds used in industrial products to have a low deposition temperature. In other words, since films can be formed at low temperatures, the organic compounds are less susceptible to the heat they receive during film formation, and thermal decomposition can be reduced.

[0174] In particular, in mass production processes, the same material is heated continuously for long periods of time, and organic compounds with high deposition temperatures are prone to decomposition. If the material decomposes, this leads to further increases in deposition temperature, making it impossible to maintain a stable mass production system. Therefore, organic compound materials that can be formed into films at low temperatures can be formed without decomposition, making stable mass production possible.

[0175] Specifically, the deposition temperature of the organic compound in the deposition apparatus is preferably 350°C or lower, preferably 330°C or lower, more preferably 300°C or lower, and even more preferably 270°C or lower. The sublimation temperature of the organic compound is preferably 350°C or lower, preferably 300°C or lower, more preferably 290°C or lower, and even more preferably 260°C or lower. It is also preferable that the 50% weight loss temperature is low when measured with a TG-DTA apparatus. A low 50% weight loss temperature means that the compound can be stably sublimated at a low temperature even if the sublimation weight increases. The 50% weight loss temperature is preferably 390°C or lower, preferably 350°C or lower, more preferably 320°C or lower, and even more preferably 300°C or lower.

[0176] The organic compound preferably has only one carbazole ring. If the organic compound has more carbazole rings, the sublimation temperature becomes higher, which in turn increases the deposition temperature, which may result in a decrease in yield in the manufacturing process.

[0177] The organic compound used in the cap layer 107 is preferably an organic compound represented by the following general formula (G1).

[0178] [ka]

[0179] However, in general formula (G1), R 1 ~R 4 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-1), and R 5 ~R 8 each independently represents hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituent represented by the following general formula (G1-3), and R 5 ~R 8 At least one of the groups is a substituent represented by the following general formula (G1-3), and Ar 11 represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 12 represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms. n11 represents an integer of 0 to 3, and n12 represents an integer of 1 to 3.

[0180] [ka]

[0181] However, in the general formula (G1-1) and the general formula (G1-3), Ar 13 , Ar 15 , and Ar 16 each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 14 , and Ar 17 each independently represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar 15 , Ar 16 and Ar 17 At least two of n13, n15, and n16 represent a bicyclic or tricyclic monovalent or divalent aromatic hydrocarbon group, or a monovalent or divalent aromatic heterocyclic group. n13, n15, and n16 each independently represent an integer of 0 to 3, and n14 and n17 each independently represent an integer of 1 to 3. n15 + n16 + n17 ≧ n13 + n14.

[0182] In the general formula (G1-1) and the general formula (G1-3), Ar 11 , Ar 13 , Ar 15 , and Ar 16 is an arylene group, and Ar 12 , Ar 14 , and Ar 17 is an aryl group. When n11 is 2 or more, multiple Ar 11 may be the same or different substituents. 12 ~Ar 17 The same applies when there are multiple Ar 11 ~Ar 17 Preferably, Ar represents a substituent consisting of carbon and hydrogen (including deuterium). 12 , Ar 14 , or Ar 17 may be hydrogen (including deuterium).

[0183] Here, in the general formula (G1), R 1 ~R 8 , and Ar 11 ~R 17 is the R described in the first embodiment. m (m is any integer), or Ar m (m is an arbitrary integer) can be referred to. m and Ar m can also be used in the first embodiment.

[0184] Specific examples of the organic compound represented by the above general formula (G1) are shown below. Note that the organic compound represented by the above general formula (G1) includes the organic compound described in Embodiment 1.

[0185] [ka]

[0186] In particular, it is preferable to use the organic compound described in Embodiment 1 or the organic compound described above for the cap layer 107. The organic compound described in Embodiment 1 has a low sublimation temperature, allowing film formation at a low deposition temperature. In other words, in mass production processes, the same material is continuously heated for a long period of time, and organic compounds with high deposition temperatures are prone to decomposition. Decomposition of the material leads to further increases in deposition temperature, making stable mass production impossible. Therefore, cap layer materials that can be formed at low temperatures can be formed without decomposition, enabling stable mass production. Furthermore, the organic compounds described above have a high refractive index in the visible range or a low ordinary light refractive index, thereby increasing light extraction efficiency and external quantum efficiency. Furthermore, the organic compounds described above have a low extinction coefficient in the visible range or a low ordinary light extinction coefficient, thereby increasing light extraction efficiency and external quantum efficiency.

[0187] Furthermore, the heat generated during deposition can be suppressed from affecting the structure on the deposition target side. In particular, the thermal budget during the formation of the cap layer to fabricate devices affects the alteration and degradation of all materials used on the deposition target side. Deterioration of the materials used on the deposition target side can lead to increased variability in device characteristics and directly to a decrease in manufacturing yield. Therefore, by depositing the cap layer at a low temperature, the alteration and degradation of the materials used on the deposition target side can be suppressed, enabling high-yield production.

[0188] Other examples of materials that can be used for the cap layer include 5,5'-diphenyl-2,2'-di-5H-[1]benzothieno[3,2-c]carbazole (abbreviation: BisBTc) and 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II).

[0189] When a π-electron-deficient heteroaromatic compound is used to form a capping layer in contact with an electrode, it may interact (form a coordinate bond) with metals such as silver (Ag), gold (Au), and aluminum (Al) used in the electrode, resulting in light absorption in the visible and near-infrared regions. In this case, light generated in the light-emitting layer may be absorbed, potentially reducing the external extraction efficiency. To prevent a decrease in the external extraction efficiency, the capping layer preferably does not contain a π-electron-deficient heteroaromatic compound. Specifically, among the organic compounds represented by General Formula (G1) of one embodiment of the present invention, those that do not have a π-electron-deficient heteroaromatic ring as a substituent are preferably used.

[0190] Furthermore, the compound used in the capping layer preferably has a high LUMO (Lowest Unoccupied Molecular Orbital) level (shallow LUMO level). Using a compound with a relatively high LUMO level may reduce light absorption due to interaction with the metal. Therefore, if the compound has a relatively high LUMO level, a compound having a π-electron-deficient heteroaromatic ring may be used as the capping layer. For example, the LUMO level of the compound used in the capping layer may be −2.7 eV or higher, more preferably −2.6 eV or higher, and even more preferably −2.5 eV or higher. Furthermore, the LUMO level of the compound used in the capping layer may be higher than the LUMO level of the compound used in the electron transport layer (e.g., the electron transport layer in contact with the electrode). Furthermore, when the light-emitting device has multiple electron transport layers (e.g., two or three layers), the LUMO level of the compound used in the capping layer may be higher than the LUMO levels of the compounds in each of the multiple electron transport layers.

[0191] Note that optical interference can be utilized by adjusting the thickness of the capping layer. For example, the organic compound represented by General Formula (G1) of one embodiment of the present invention has a high ordinary light refractive index, so the thickness at which the light extraction efficiency is maximized can be thinned, and the amount of material used can be reduced. Specifically, the maximum emission efficiency can be achieved by setting the thickness of the capping layer used for a blue light-emitting element to around 60 nm, in the range of 50 nm to 70 nm.

[0192] <Light-emitting layer> The light-emitting layers (113, 113a, 113b) are layers containing a light-emitting substance. Light-emitting substances that can be used for the light-emitting layers (113, 113a, 113b) include substances that emit light of colors such as blue, purple, blue-purple, green, yellow-green, yellow, orange, and red. When multiple light-emitting layers are provided, different light-emitting substances can be used for each light-emitting layer to produce different light-emitting colors (for example, white light emission obtained by combining complementary light-emitting colors). Furthermore, a stacked structure in which each light-emitting layer contains different light-emitting substances may be used.

[0193] Furthermore, the light-emitting layers (113, 113a, 113b) may contain one or more organic compounds (host materials, etc.) in addition to the light-emitting substance (guest material).

[0194] When multiple host materials are used in the light-emitting layers (113, 113a, and 113b), it is preferable to use a substance having a larger energy gap as the second host material than the energy gaps of the existing guest material and the first host material. Furthermore, it is preferable that the lowest singlet excitation energy level (S1 level) of the second host material be higher than the S1 level of the first host material, and the lowest triplet excitation energy level (T1 level) of the second host material be higher than the T1 level of the guest material. Furthermore, it is preferable that the lowest triplet excitation energy level (T1 level) of the second host material be higher than the T1 level of the first host material. This structure allows the formation of an exciplex using two types of host materials. To efficiently form an exciplex, it is particularly preferable to combine a compound that easily accepts holes (hole-transporting material) with a compound that easily accepts electrons (electron-transporting material). This structure also allows the simultaneous realization of high efficiency, low voltage, and long life.

[0195] The organic compounds used as the host materials (including the first host material and the second host material) may be hole-transporting materials usable in the hole-transporting layers (112, 112a, and 112b) described above or electron-transporting materials usable in the electron-transporting layers (114, 114a, and 114b) described below, as long as they satisfy the requirements for a host material used in an emitting layer. These organic compounds may also be exciplexes composed of multiple organic compounds (the first host material and the second host material described above). An exciplex (also referred to as an exciplex) formed by multiple organic compounds in an excited state has an extremely small difference between the S1 and T1 levels and functions as a TADF material capable of converting triplet excitation energy into singlet excitation energy. A combination of multiple organic compounds that form an exciplex is preferably one in which one of the compounds has a π-electron-deficient heteroaromatic ring and the other has a π-electron-rich heteroaromatic ring. As a combination for forming an exciplex, one of the compounds may be a phosphorescent material such as an iridium-, rhodium-, or platinum-based organometallic complex or a metal complex. The organic compound described in Embodiment 1 can be effectively used as a first host material because it has an electron-transporting property. In addition, it can also be used as a second host material because it has a hole-transporting property.

[0196] There are no particular limitations on the light-emitting substances that can be used in the light-emitting layers (113, 113a, 113b), and light-emitting substances that convert singlet excitation energy into light emission in the visible light range, or light-emitting substances that convert triplet excitation energy into light emission in the visible light range, can be used.

[0197] [Light-emitting materials that convert singlet excitation energy into luminescence] Examples of luminescent materials that convert singlet excitation energy into luminescence and can be used in the luminescent layers (113, 113a, 113b) include the following fluorescent substances (fluorescent luminescent materials): pyrene derivatives, anthracene derivatives, triphenylene derivatives, fluorene derivatives, carbazole derivatives, dibenzothiophene derivatives, dibenzofuran derivatives, dibenzoquinoxaline derivatives, quinoxaline derivatives, pyridine derivatives, pyrimidine derivatives, phenanthrene derivatives, and naphthalene derivatives. Pyrene derivatives are particularly preferred because of their high luminescence quantum yield. Specific examples of pyrene derivatives include 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'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(dibenzofuran-2-yl)-N,N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6FrAPrn), N,N'-bis(dibenzothiophen-2-yl)-N, N'-diphenylpyrene-1,6-diamine (abbreviation: 1,6ThAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-6-amine] (abbreviation: 1,6BnfAPrn), N,N'-(pyrene-1,6-diyl)bis[(N-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-02), N,N'-(pyrene-1,6-diyl)bis[(6,N-diphenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), and the like.

[0198] In addition, 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'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)phenyl N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviation: PCAPA), 4-(10-phenyl-9-anthryl)-4'-(9,10-diphenyl-2-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), 4-(10-phenyl-9-anthryl)-4'- (9-Phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), 4-[4-(10-phenyl-9-anthryl)phenyl]-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPBA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenyl) N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), and the like can be used.

[0199] In addition, 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]ethenyl}-6-methyl-4H-pyran-4-ylidene)propanedinit (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhA FD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB),6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-ylidene)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), 1,6BnfAPrn-0 3, N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazol-2-yl)naphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviated as 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviated as 3,10FrA2Nbf(IV)-02), etc. In particular, pyrenediamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 can be used.

[0200] [Light-emitting materials that convert triplet excitation energy into luminescence] Next, examples of luminescent materials that can be used in the luminescent layer 113 and convert triplet excitation energy into luminescence include phosphorescent materials and thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0201] A phosphorescent material is a compound that exhibits phosphorescence but does not exhibit fluorescence at a temperature range from low temperatures (e.g., 77 K) to room temperature (i.e., 77 K to 313 K). The phosphorescent material preferably contains a metal element with a large spin-orbit interaction, such as an organometallic complex, a metal complex (platinum complex), or a rare-earth metal complex. Specifically, a transition metal element is preferred, and a platinum group element (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt)) is particularly preferred. Among these, iridium is preferred because it can increase the transition probability associated with the direct transition between the singlet ground state and the triplet excited state.

[0202] [Phosphorescent material (450 nm to 570 nm: blue or green)] Examples of phosphorescent materials that exhibit blue or green light and have an emission spectrum with a peak wavelength of 450 nm or more and 570 nm or less include the following materials.

[0203] For example, 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-triazolato)iridium(III) (abbreviation: [Ir(Mptz)3]), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato] Organometallic complexes containing a 4H-triazole ring, such as iridium(III) (abbreviation: [Ir(iPrptz-3b)3]), tris[3-(5-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(iPr5btz)3]), tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp)3]), tris(1- Organometallic complexes containing a 1H-triazole ring, such as methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Prptz1-Me)3]), 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(II) Iridium(III) tetrakis(1-pyrazolyl)borate (abbreviated as FIr6), bis[2-(4',6'-difluorophenyl)pyridinato-N,C2']iridium(III) picolinate (abbreviated as FIrpic), and bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinato-N,C2']iridium(III) tetrakis(1-pyrazolyl)borate (abbreviated as FIr6). 2’}iridium(III) picolinate (abbreviation: [Ir(CF3ppy)2(pic)]), bis[2-(4',6'-difluorophenyl)pyridinato-N,C 2’] Organometallic complexes with a phenylpyridine derivative having an electron-withdrawing group as a ligand, such as iridium(III) acetylacetonate (abbreviation: FIr(acac)), are also included.

[0204] [Phosphorescent material (495nm to 590nm: green or yellow)] Examples of phosphorescent materials that exhibit green or yellow color and have an emission spectrum with a peak wavelength of 495 nm or more and 590 nm or less include the following materials.

[0205] For example, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)3]), tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm)3]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(tBuppm)2(acac)]), (acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm)2(acac)]), (acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm )2(acac)]), (acetylacetonato)bis{4,6-dimethyl-2-[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl-κC}iridium(III) (abbreviation: [Ir(dmppm-dmp)2(acac)]), and (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm)2(acac)]). iridium complexes, organometallic iridium complexes containing a pyrazine ring such as (acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me)2(acac)]) and (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr)2(acac)]), 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)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-phenyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy)2(4dppy)]), bis[2-(2-pyridinyl-κN)phenyl-κC][2-(4-methyl-5-phenyl-2-pyridinyl -κN)phenyl-κC], [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: Ir(5mppy-d3)2(mbfpypy-d3)), {2-(methyl-d3)-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro Ir(2,3-b)pyridin-7-yl-κC}bis{5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviated as Ir(5mtpy-d6)2(mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC] Organometallic iridium complexes containing a pyridine ring, such as [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy)2(mbfpypy-d3)), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy)2(mdppy)), and bis(2,4-diphenyl-1,3-oxazolato-N,C 2’) Iridium(III) acetylacetonate (abbreviation: [Ir(dpo)2(acac)]), bis{2-[4'-(perfluorophenyl)phenyl]pyridinato-N,C 2’}Iridium(III) acetylacetonate (abbreviation: [Ir(p-PF-ph)2(acac)]), bis(2-phenylbenzothiazolato-N,C 2’ ) iridium(III) acetylacetonate (abbreviated as [Ir(bt)2(acac)]), as well as rare earth metal complexes such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviated as [Tb(acac)3(Phen)]).

[0206] [Phosphorescent material (570nm to 750nm: yellow or red)] Examples of phosphorescent materials that exhibit yellow or red color and have an emission spectrum with a peak wavelength of 570 nm or more and 750 nm or less include the following materials.

[0207] For example, pyrimidinato]iridium(III) such as (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)2(dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm)2(dpm)]), and (dipivaloylmethanato)bis[4,6-di(naphthalen-1-yl)pyrimidinato]iridium(III) (abbreviation: [Ir(d1npm)2(dpm)]). Organometallic complexes containing an imidine ring, (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr)2(acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr)2(dpm)]), and bis{4,6-dimethyl-2-[3-(3,5-dimethylphenyl)-5-phenyl-2-pyrazinyl-κN]phenyl-κC}(2,6-dimethyl-3,5-heptanedionato-κN). 2O,O')iridium(III) (abbreviation: [Ir(dmdppr-P)2(dibm)]), bis{4,6-dimethyl-2-[5-(4-cyano-2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]phenyl-κC}(2,2,6,6-tetramethyl-3,5-heptanedionato-κ) 2 O,O')iridium(III) (abbreviation: [Ir(dmdppr-dmCP)2(dpm)]), bis{2-[5-(2,6-dimethylphenyl)-3-(3,5-dimethylphenyl)-2-pyrazinyl-κN]-4,6-dimethylphenyl-κC}(2,2',6,6'-tetramethyl-3,5-heptanedionato-κO,O')iridium(III) (abbreviation: [Ir(dmdppr-dmp)2(dpm)]), (acetylacetonato)bis(2-methyl-3-phenylquinoxalinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(mpq)2(acac)]), (acetylacetonato)bis(2,3-diphenylquinoxalinato-N,C 2’ )iridium(III) (abbreviation: [Ir(dpq)2(acac)]), organometallic complexes with a pyrazine ring such as (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq)2(acac)]), tris(1-phenylisoquinolinato-N,C 2’ ) Iridium(III) (abbreviation: [Ir(piq)3]), bis(1-phenylisoquinolinato-N,C 2’ ) iridium(III) acetylacetonate (abbreviation: [Ir(piq)2(acac)]), and bis[4,6-dimethyl-2-(2-quinolinyl-κN)phenyl-κC](2,4-pentanedionato-κ 2These include organometallic complexes with a pyridine ring, such as (O,O')iridium(III) (abbreviation: [Ir(dmpqn)2(acac)]), platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrinplatinum(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)]), and tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA)3(Phen)]).

[0208] [TADF material] The following materials can be used as TADF materials. TADF materials are materials that have a small difference between the S1 level and the T1 level (preferably 0.2 eV or less), can upconvert a triplet excited state to a singlet excited state with a small amount of thermal energy (reverse intersystem crossing), and efficiently emit light (fluorescence) from the singlet excited state. Conditions for efficiently obtaining thermally activated delayed fluorescence include an energy difference between the triplet excited energy level and the singlet excited energy level of 0 eV or more and 0.2 eV or less, preferably 0 eV or more and 0.1 eV or less. Delayed fluorescence in TADF materials refers to light emission that has a spectrum similar to that of normal fluorescence but has a significantly long lifetime. Its lifetime is 1×10 -6 seconds or 1×10 -3 More than a second.

[0209] The TADF material can also be used as an electron transporting material, a hole transporting material, or a host material.

[0210] Examples of TADF materials include fullerene and its derivatives, acridine derivatives such as proflavine, eosin, etc. Also included are metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd). Examples of metal-containing porphyrins include protoporphyrin-tin fluoride complex (abbreviation: SnF2(Proto IX)), mesoporphyrin-tin fluoride complex (abbreviation: SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (abbreviation: SnF2(Hemato IX)), coproporphyrin tetramethyl ester-tin fluoride complex (abbreviation: SnF2(Copro III-4Me)), octaethylporphyrin-tin fluoride complex (abbreviation: SnF2(OEP)), etioporphyrin-tin fluoride complex (abbreviation: SnF2(Etio I)), and octaethylporphyrin-platinum chloride complex (abbreviation: PtCl2OEP).

[0211] [ka]

[0212] Other examples include 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 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-phenoxy) 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9, 9-Dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracen]-10'-one (abbreviation: ACRSA), 4-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)benzofuro[3,2-d]pyrimidine (abbreviation: 4PCCzBfpm), 4-[4-(9'-phenyl-3,3'- Heteroaromatic compounds having a π-electron rich heteroaromatic compound and a π-electron deficient heteroaromatic compound, such as 9-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), may also be used.

[0213] In addition, a substance in which a π-electron-rich heteroaromatic compound and a π-electron-deficient heteroaromatic compound are directly bonded is particularly preferable because the donor property of the π-electron-rich heteroaromatic compound and the acceptor property of the π-electron-deficient heteroaromatic compound are both strong, thereby reducing the energy difference between the singlet excited state and the triplet excited state. Furthermore, a TADF material (TADF100) in which the singlet excited state and the triplet excited state are in thermal equilibrium may also be used as the TADF material. Such TADF materials have a short emission lifetime (excitation lifetime), which can suppress efficiency decline in light-emitting devices in the high-brightness range.

[0214] [ka]

[0215] In addition to the above, examples of materials capable of converting triplet excitation energy into luminescence include nanostructures of transition metal compounds having a perovskite structure. Nanostructures of metal halide perovskites are particularly preferred. Nanoparticles and nanorods are preferred as such nanostructures.

[0216] In the light-emitting layers (113, 113a, 113b, 113c), one or more substances having an energy gap larger than the energy gap of the light-emitting substance (guest material) may be selected and used as the organic compound (host material, etc.) used in combination with the above-mentioned light-emitting substance (guest material).

[0217] [Fluorescent host material] When the light-emitting substance used in the light-emitting layers (113, 113a, 113b, and 113c) is a fluorescent light-emitting substance, it is preferable to use, as the organic compound (host material) to be combined, an organic compound having a high energy level in a singlet excited state and a low energy level in a triplet excited state, or an organic compound with a high fluorescence quantum yield. Therefore, as long as the organic compound satisfies these conditions, the hole-transporting material (described above) and the electron-transporting material (described below) shown in this embodiment can be used. In addition, the organic compounds described in Embodiment 1 can be used.

[0218] Although some of the examples overlap with those described above, examples of the organic compound (host material) that can be preferably combined with the light-emitting substance (fluorescent light-emitting substance) include condensed polycyclic aromatic compounds such as anthracene derivatives, tetracene derivatives, phenanthrene derivatives, pyrene derivatives, chrysene derivatives, and dibenzo[g,p]chrysene derivatives.

[0219] Specific examples of organic compounds (host materials) that are preferably used in combination with fluorescent materials include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: DPCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9,10-diphenylanthracene (abbreviation: DPAnth), N,N ... N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazol-3-amine (abbreviated as CzA1PA), 4-(10-phenyl-9-anthryl)triphenylamine (abbreviated as DPhPA), YGAPA, PCAPA, N,9-diphenyl-N-{4-[4-(10-phenyl-9-anthryl)phenyl]phenyl}-9H-carbazol-3-amine (abbreviated as PCAPBA), N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazol-3-amine (abbreviated as 2PCAPA) , 6,12-dimethoxy-5,11-diphenylchrysene, N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 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), 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,β-ADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)benzo[b]naphtho[2,3-d]furan (abbreviated as Bnf(II)PhA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviated as αN-βNPAnth), 2,9-di(1-naphthyl)-10-phenylanthracene (abbreviated as 2αN-αNPhA), 9-(1-naphthyl)-10-[3-(1-naphthyl)phenyl]anthracene (abbreviation: αN-mαNPAnth), 9-(2-naphthyl)-10-[3-(1-naphthyl)phenyl]anthracene (abbreviation: βN-mαNPAnth), 9-(1-naphthyl)-10-[4-(1-naphthyl)phenyl]anthracene (abbreviation: αN-αNPAnth), 9-(2-naphthyl)-10-[4-(2-naphthyl)phenyl] Anthracene (abbreviation: βN-βNPAnth), 2-(1-naphthyl)-9-(2-naphthyl)-10-phenylanthracene (abbreviation: 2αN-βNPhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthracenyl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtB ImPBPhA), 9,9'-bianthryl (abbreviated as BANT), 9,9'-(stilbene-3,3'-diyl)diphenanthrene (abbreviated as DPNS), 9,9'-(stilbene-4,4'-diyl)diphenanthrene (abbreviated as DPNS2), 1,3,5-tri(1-pyrenyl)benzene (abbreviated as TPB3), 5,12-diphenyltetracene, 5,12-bis(biphenyl-2-yl)tetracene, etc.

[0220] [Phosphorescent host materials] Furthermore, when the light-emitting substance used in the light-emitting layers (113, 113a, 113b, 113c) is a phosphorescent light-emitting substance, an organic compound having a triplet excitation energy higher than the triplet excitation energy (energy difference between the ground state and the triplet excited state) of the light-emitting substance can be selected as the organic compound (host material) to be combined. Note that when multiple organic compounds (for example, a first host material and a second host material (or assist material)) are used in combination with the light-emitting substance to form an exciplex, it is preferable to use these multiple organic compounds as a mixture with the phosphorescent light-emitting substance. Furthermore, the organic compounds described in Embodiment 1 can be used.

[0221] A compound having a naphthalene ring may be used as the host material. The presence of a naphthalene ring can increase the electron transport property or Tg. A compound having an anthracene ring and a naphthalene ring may also be used. The number of naphthalene rings in the host material is preferably the same as, or preferably less than, the number of naphthalene rings in the cap layer material.

[0222] With this structure, it is possible to efficiently obtain light emission using Exciplex-Triplet Energy Transfer (ExTET), which is an energy transfer from an exciplex to a light-emitting substance. As a combination of multiple organic compounds, it is preferable to use one that easily forms an exciplex, and it is particularly preferable to combine a compound that easily accepts holes (hole transport material) with a compound that easily accepts electrons (electron transport material).

[0223] Although some of the examples overlap with those described above, from the viewpoint of a preferable combination with the light-emitting substance (phosphorescent light-emitting substance), examples of the organic compound (host material, assist material) include aromatic amines (organic compounds having an aromatic amine skeleton), carbazole derivatives (organic compounds having a carbazole ring), dibenzothiophene derivatives (organic compounds having a dibenzothiophene ring), dibenzofuran derivatives (organic compounds having a dibenzofuran ring), oxadiazole derivatives (organic compounds having an oxadiazole ring), triazole derivatives (organic compounds having a triazole ring), benzimidazole derivatives (benzoyl midazole ring), quinoxaline derivatives (organic compounds having a quinoxaline ring), dibenzoquinoxaline derivatives (organic compounds having a dibenzoquinoxaline ring), pyrimidine derivatives (organic compounds having a pyrimidine ring), triazine derivatives (organic compounds having a triazine ring), pyridine derivatives (organic compounds having a pyridine ring), bipyridine derivatives (organic compounds having a bipyridine ring), phenanthroline derivatives (organic compounds having a phenanthroline ring), furodiazine derivatives (organic compounds having a furodiazine ring), zinc- and aluminum-based metal complexes, and the like.

[0224] Among the organic compounds, specific examples of the aromatic amine and carbazole derivative, which are organic compounds with high hole-transporting properties, are the same as the specific examples of the hole-transporting material described above, and any of these is preferable as the host material.

[0225] Specific examples of the dibenzothiophene derivatives and dibenzofuran derivatives, which are organic compounds with high hole transport properties among the above organic compounds, include 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), DBT3P-II, 2,8-dipheny Examples of suitable host materials include 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 4-[3-(triphenylen-2-yl)phenyl]dibenzothiophene (abbreviation: mDBTPTp-II).

[0226] Other preferred host materials include metal complexes having oxazole- or thiazole-based ligands, such as bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO) and bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ).

[0227] Specific examples of the organic compounds having high electron transport properties, such as oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, quinazoline derivatives, and phenanthroline derivatives, among the above organic compounds, include 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 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), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5 Organic compounds containing heteroaromatic rings with polyazole rings, such as 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2,2'-biphenyl-4,4'-diylbis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), and 2,2'-biphenyl-4,4'-diylbis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P). Organic compounds containing heteroaromatic rings with a pyridine ring, such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4-(3,6-diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 7mDBTPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviated as 6mDBTPDB q-II), 2-{4-[9,10-di(2-naphthyl)-2-anthryl]phenyl}-1-phenyl-1H-benzimidazole (abbreviation: ZADN), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), etc., all of which are preferred as host materials.

[0228] Specific examples of the pyridine derivatives, diazine derivatives (including pyrimidine derivatives, pyrazine derivatives, and pyridazine derivatives), triazine derivatives, and furodiazine derivatives, which are organic compounds with high electron transport properties among the above organic compounds, include 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), and 4,6-bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II). Pyrimidine (abbreviation: 4,6mCzP2Pm), 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), 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1 ,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 8-(biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2- d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 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), 11-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation: 11mDBtBPPnfpr), 11-[3'-(dibenzothiophen-4-yl)biphenyl-4-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 11-[3'-(9H-carbazol-9-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 12-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)phenanthro[9',10':4,5]furo[2,3-b]pyrazine (abbreviation: 12PCCzPnfpr), 9-[3'-(9 -phenyl-9H-carbazol-3-yl)biphenyl-4-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 9pmPCBPNfpr), 9-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 9PCCzNfpr), 10-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviated as 10PCCzNfpr), 9-[3'-(6-phenylbenzo[b]naphtho [1,2-d]furan-8-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mBnfBPNfpr), 9-{3-[6-(9,9-dimethylfluoren-2-yl)dibenzothiophen-4-yl]phenyl}naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mFDBtPNfpr), 9-[3'-(6-phenyldibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr-02), 9-[3-(9'-phenyl-3,3'-bi-9H-carbazol-9-yl)phenyl]naphtho[1',2':4,5]furo[2,3-b]pyrazine (abbreviation: 9mPCCzPNfpr), 9-[3'-(2,8-diphenyldibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]furo[2,3-b]pyrazine, 11-[3'-(2,8-diphenyldibenzothiophen-4-yl)biphenyl-3-yl]phenanthro[9',10':4,5]furo[2,3-b]pyrazine, 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'-(triphenylen-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 2-(biphenyl-4-yl)-4-phenyl-6-(9, 9'-Spirobi[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 3-[9-(4,6-diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-furan Examples of suitable host materials include organic compounds containing heteroaromatic rings with diazine rings, such as 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), 6-(biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), and 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm).

[0229] Furthermore, among the above organic compounds, specific examples of metal complexes, which are organic compounds with high electron-transporting properties, include zinc- or aluminum-based metal complexes such as tris(8-quinolinolato)aluminum(III) (abbreviation: Alq), tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq2), bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), and bis(8-quinolinolato)zinc(II) (abbreviation: Znq), as well as metal complexes having a quinoline ring or a benzoquinoline ring, all of which are preferable as the host material.

[0230] Other preferred host materials include polymer compounds such as poly(2,5-pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine-6,6'-diyl)] (abbreviation: PF-BPy).

[0231] Furthermore, we have developed bipolar organic compounds with high hole-transporting and electron-transporting properties, such as 9-phenyl-9'-(4-phenyl-2-quinazolinyl)-3,3'-bi-9H-carbazole (abbreviation: PCCzQz), 2-[4'-(9-phenyl-9H-carbazol-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 5-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[ Organic compounds having a diazine ring, such as [2,1-b]carbazole (abbreviation: mINc(II)PTzn), 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), and 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), can also be used as the host material.

[0232] <Hole injection layer> The hole injection layer (111, 111a, 111b) is a layer that injects holes from the first electrode 101, which is an anode, and the charge generation layer (106, 106a, 106b) into the organic compound layer (103, 103a, 103b), and is a layer that contains an organic acceptor material and a material with high hole injection properties.

[0233] In the hole-injection layers (111, 111a, 111b), the organic compound having hole-transporting properties used in the composite material is more preferably a substance having a relatively low HOMO (Highest Occupied Molecular Orbital) level of −5.7 eV or more and −5.4 eV or less. When the organic compound having hole-transporting properties used in the composite material has a relatively low HOMO level, injection of holes into the hole-transporting layer becomes easy, and a light-emitting device with a long lifetime can be easily obtained. Furthermore, when the organic compound having hole-transporting properties used in the composite material is a substance having a relatively low HOMO level, hole induction is appropriately suppressed, and a light-emitting device with a long lifetime can be obtained.

[0234] The hole injection layer (111, 111a, 111b) functions to promote hole injection by reducing the hole injection barrier from one of the pair of electrodes (the first electrode 101 or the second electrode 102). It is formed, for example, from a transition metal oxide, a phthalocyanine derivative, or an aromatic amine. Examples of transition metal oxides include molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide. Examples of phthalocyanine derivatives include phthalocyanine and metal phthalocyanine. Examples of aromatic amines include benzidine derivatives and phenylenediamine derivatives. Polymer compounds such as polythiophene and polyaniline can also be used. A typical example is poly(ethylenedioxythiophene) / polystyrene sulfonic acid, which is a self-doped polythiophene.

[0235] The hole-injection layers (111, 111a, 111b) may be layers containing a composite material of a hole-transporting material and a material exhibiting electron-accepting properties. Alternatively, a stack of a layer containing an electron-accepting material and a layer containing a hole-transporting material may be used. Charge transfer is possible between these materials in a steady state or under the presence of an electric field. Examples of electron-accepting materials include organic acceptors such as quinodimethane derivatives, chloranil derivatives, and hexaazatriphenylene derivatives. Specific examples include compounds having an electron-withdrawing group (halogen or cyano group), such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F4-TCNQ), chloranil, and 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as HAT-CN). Alternatively, transition metal oxides, such as oxides of metals from Groups 4 to 8, can be used. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is preferred because it is stable in the air, has low hygroscopicity, and is easy to handle.

[0236] As the hole transporting material, a material having a higher hole transporting property than electron transporting property can be used. -6 cm 2 A material having a hole mobility of 1 / Vs or more is preferable. Specifically, aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, and the like, which are listed as hole-transporting materials that can be used for the light-emitting layer 113, can be used. The organic compound represented by General Formula (G1) of one embodiment of the present invention is also a carbazole derivative. The hole-transporting material may be a polymer compound.

[0237] <Hole transport layer> The hole transport layers (112, 112a, 112b) are layers containing a hole transport material, and the hole transport materials exemplified as the material for the hole injection layers (111, 111a, 111b) can be used. The hole transport layers (112, 112a, 112b) have the function of transporting holes injected into the hole injection layers (111, 111a, 111b) to the light-emitting layers (113, 113a, 113b), and therefore preferably have a HOMO level that is the same as or close to the HOMO level of the hole injection layers (111, 111a, 111b).

[0238] Also, 1×10 -6 cm 2 It is preferable that the material has a hole mobility of 1 / Vs or more. However, other materials may be used as long as they have a higher hole transporting property than electron transporting property. Note that the layer containing the material with a high hole transporting property may be a single layer or may be a stack of two or more layers made of the above material.

[0239] The hole transport layer or hole injection layer preferably has a smaller ordinary refractive index than the cap layer. The hole transport layer or hole injection layer preferably has a smaller ordinary refractive index than the light-emitting layer. Specifically, the ordinary refractive indexes of the hole transport material, the host material for the light-emitting layer, and the cap layer material when each is formed into a film can be compared. It is preferable that the ordinary refractive indexes of the films satisfy the relationship hole transport material < host material < cap layer material, since this can improve extraction efficiency.

[0240] The total thickness (thickness m) of the layers (e.g., transparent electrode, hole injection layer, hole transport layer, and electron blocking layer) sandwiched between the reflective electrode and the light-emitting layer is preferably determined by utilizing optical interference (microcavity), because this increases the light extraction efficiency. In this case, it is more preferable that the layer having thickness m has a stacked structure of a layer (layer L) with a low ordinary refractive index and a layer (layer H) with a higher ordinary refractive index than that of layer L, and that light incident from the light-emitting layer is reflected at the interface between layer L and layer H and amplified by optical interference. In this case, the difference in ordinary refractive index between layer L and layer H at the emission wavelength of the light-emitting element is preferably 0.1 or more, more preferably 0.2 or more, and even more preferably 0.3 or more, because this increases the interfacial reflection. The organic compound represented by general formula (G1) of one embodiment of the present invention has a high refractive index and can therefore be used as layer H.

[0241] ≪Electron transport layer≫ The electron transport layers (114, 114a, 114b) have a function of transporting electrons injected from the other of the pair of electrodes (the first electrode 101 or the second electrode 102) through the electron injection layers (115, 115a, 115b) to the light-emitting layer 113. As the electron transport material, a material having a higher electron transporting property than a hole transporting property can be used, and the electron transporting property is 1×10 -6 cm 2 / Vs or more. Compounds that readily accept electrons (materials with electron transport properties) that can be used include compounds having a π-electron-deficient heteroaromatic ring skeleton, such as nitrogen-containing heteroaromatic compounds, and organometallic complexes. Specific examples include organometallic complexes having a quinoline ligand, a benzoquinoline ligand, an oxazole ligand, or a thiazole ligand, which are listed as electron transport materials that can be used in the light-emitting layer 113. Other examples include oxadiazole derivatives, triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, and triazine derivatives. 1×10 -6 cm 2It is preferable that the electron transport layer is a substance having an electron mobility of 1 / Vs or higher. Note that other substances may be used as the electron transport layer as long as they have a higher electron transporting property than hole transporting property. The electron transport layer (114, 114a, 114b) may be a single layer or a stack of two or more layers made of the above substances.

[0242] A compound having a naphthalene ring may also be used as the electron transport material. Naphthalene has higher reactivity than, for example, benzene, and is advantageous from the viewpoint of synthesis. Furthermore, a compound containing naphthalene can enhance electron transport properties or Tg. Furthermore, the electron transport layer can enhance light extraction efficiency by reducing the ordinary refractive index. Therefore, the number of naphthalene rings contained in the electron transport material is preferably two or less, and preferably one. Furthermore, it is preferable that the ordinary refractive index of the electron transport layer is smaller than that of the cap layer. Therefore, the number of naphthalene rings contained in the electron transport material is the same as, or preferably smaller than, the number of naphthalene rings contained in the cap layer material. For example, an azine compound (a compound having a triazine skeleton or a pyrimidine skeleton) containing a naphthalene ring can be used as the electron transport material. Note that the difference in ordinary refractive index between the electron transport layer and the cap layer may be small as long as light extraction efficiency is obtained. In this case, the same organic compound can be used for the electron transport layer and the cap layer.

[0243] A compound having a cyano group may also be used as the electron transport material. Using a compound having a cyano group in the electron transport layer may reduce the device's driving voltage, improve efficiency, or extend the device's lifespan. However, since a large number of cyano groups may disrupt the carrier balance within the device, the number of cyano groups should be two or less, preferably one or less. The number of cyano groups contained in the electron transport material should be the same as or preferably less than the number of cyano groups contained in the cap layer material. Examples of electron transport materials that can be used include azine compounds containing a cyano group and azine compounds containing a cyano group and a naphthalene ring.

[0244] In addition, a compound having an anthracene ring (also referred to as an anthracene compound) can be used as the electron transport material. Furthermore, by using a structure having a naphthyl ring, the electron transport property or Tg can be improved. Therefore, a structure having an anthracene ring and a naphthalene ring may be used. It is preferable that the number of naphthalene rings contained in the electron transport material is smaller than the number of naphthalene rings contained in the cap layer material.

[0245] In addition, it is preferable that the electron transport layer or the electron injection layer has a smaller ordinary refractive index than the light emitting layer. When the capping layer is included, it is preferable that the ordinary refractive index of the film formed from the capping layer satisfies the relationship of electron transport material < host material < capping layer material, since this can improve extraction efficiency.

[0246] Furthermore, a layer for controlling the movement of electron carriers may be provided between the electron transport layer (114, 114a, 114b) and the light-emitting layer (113, 113a, 113b). This layer is made by adding a small amount of a substance with high electron trapping properties to a material with high electron transport properties as described above, and by suppressing the movement of electron carriers, it becomes possible to adjust the carrier balance. Such a configuration is highly effective in suppressing problems (e.g., a reduction in device life) caused by electrons passing through the light-emitting layer.

[0247] ≪Electron injection layer≫ The electron injection layer (115, 115a, 115b) has a function of promoting electron injection by reducing the electron injection barrier from the second electrode 102, and can be made of, for example, a Group 1 metal, a Group 2 metal, or an oxide, halide, or carbonate thereof. Also, a composite material of the above-mentioned electron transport material and a material that exhibits electron donating properties can be used. Examples of materials that exhibit electron donating properties include Group 1 metals, Group 2 metals, or oxides thereof. Specific examples include lithium fluoride (LiF), sodium fluoride (NaF), cesium fluoride (CsF), calcium fluoride (CaF2), and lithium oxide (LiO xAlkali metals, alkaline earth metals, or compounds thereof such as fluoride (ErF3) can be used. Rare earth metal compounds such as erbium fluoride (ErF3) can also be used. Electrides can also be used for the electron injection layer 115. Examples of such electrides include a substance in which a high concentration of electrons is added to a mixed oxide of calcium and aluminum. Materials that can be used for the electron transport layers (114, 114a, 114b) can also be used for the electron injection layers (115, 115a, 115b).

[0248] The electron injection layer (115, 115a, 115b) may also be made of a composite material containing an organic compound and an electron donor (donor). Such composite materials have excellent electron injection and transport properties because electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material that is excellent at transporting the generated electrons. Specifically, the above-mentioned substances constituting the electron transport layer 114 (organometallic complexes, heteroaromatic compounds, etc.) can be used. The electron donor may be any substance that exhibits electron donating properties to the organic compound. Specifically, alkali metals, alkaline earth metals, or rare earth metals are preferred, such as lithium, sodium, cesium, magnesium, calcium, erbium, and ytterbium. Alkali metal oxides or alkaline earth metal oxides are preferred, such as lithium oxide, calcium oxide, and barium oxide. Lewis bases such as magnesium oxide can also be used. Organic compounds such as tetrathiafulvalene (TTF) can also be used.

[0249] The light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer can be formed by vapor deposition (including vacuum deposition), inkjet printing, coating, gravure printing, etc. In addition to the materials described above, the light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer may be made of inorganic compounds such as quantum dots or polymeric compounds (oligomers, dendrimers, polymers, etc.).

[0250] Quantum dots may be colloidal quantum dots, alloy quantum dots, core-shell quantum dots, core quantum dots, etc. Quantum dots containing elements from groups 2 and 16, 13 and 15, 13 and 17, 11 and 17, or 14 and 15 may also be used. Quantum dots containing elements such as cadmium (Cd), selenium (Se), zinc (Zn), sulfur (S), phosphorus (P), indium (In), tellurium (Te), lead (Pb), gallium (Ga), arsenic (As), and aluminum (Al) may also be used.

[0251] <Pair of electrodes> The first electrode 101 and the second electrode 102 function as an anode or a cathode of the light-emitting element. The first electrode 101 and the second electrode 102 can be formed using a metal, an alloy, a conductive compound, a mixture thereof, a stacked body thereof, or the like.

[0252] One of the first electrode 101 and the second electrode 102 is preferably formed of a conductive material having a light-reflecting function. Examples of the conductive material include aluminum (Al) and alloys containing Al. Examples of alloys containing Al include alloys containing Al and L (L represents one or more of titanium (Ti), neodymium (Nd), nickel (Ni), and lanthanum (La)), such as alloys containing Al and Ti, or Al, Ni, and La. Aluminum (Al) has low resistance and high light reflectance. Furthermore, aluminum (Al) is abundant in the earth's crust and inexpensive, so the use of Al can reduce the manufacturing cost of light-emitting elements. Alternatively, an alloy containing silver (Ag) or Ag and N (N represents one or more of yttrium (Y), Nd, magnesium (Mg), ytterbium (Yb), Al, Ti, gallium (Ga), zinc (Zn), indium (In), tungsten (W), manganese (Mn), tin (Sn), iron (Fe), Ni, copper (Cu), palladium (Pd), iridium (Ir), or gold (Au)) may be used. Examples of alloys containing silver (Ag) include alloys containing silver, palladium, and copper, alloys containing silver and copper, alloys containing silver and magnesium, alloys containing silver and nickel, alloys containing silver and gold, and alloys containing silver and ytterbium. Other transition metals that can be used include tungsten, chromium (Cr), molybdenum (Mo), copper, and titanium.

[0253] Furthermore, light emitted from the light-emitting layer is extracted through one or both of the first electrode 101 and the second electrode 102. Therefore, at least one of the first electrode 101 and the second electrode 102 is preferably formed from a conductive material that has a light-transmitting function. The conductive material has a visible light transmittance of 40% or more and 100% or less, preferably 60% or more and 100% or less, and a resistivity of 1×10 -2 Examples include conductive materials with a resistance of Ω·cm or less.

[0254] The first electrode 101 and the second electrode 102 may be formed of a conductive material that has both a light transmitting and a light reflecting function. The conductive material has a visible light reflectance of 20% to 80%, preferably 40% to 70%, and a resistivity of 1×10 -2 Examples of suitable conductive materials include those with a resistivity of Ω·cm or less. For example, the conductive layer can be formed using one or more conductive metals, alloys, conductive compounds, etc. Specifically, metal oxides such as indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide (abbreviated as ITSO), indium zinc oxide, titanium-containing indium tin oxide, indium titanium oxide, and indium oxide containing tungsten oxide and zinc oxide can be used. Alternatively, a thin metal film that is light-transmitting (preferably, a thickness of 1 nm to 30 nm) can be used. Examples of suitable metals include Ag, and alloys such as Ag and Al, Ag and Mg, Ag and Au, and Ag and Yb.

[0255] In this specification and the like, the material having the function of transmitting light may be any material that has the function of transmitting visible light and is conductive, and includes, for example, oxide conductors such as ITO as described above, as well as oxide semiconductors or organic conductors containing organic substances. Examples of organic conductors containing organic substances include composite materials obtained by mixing an organic compound with an electron donor (donor), and composite materials obtained by mixing an organic compound with an electron acceptor. In addition, inorganic carbon-based materials such as graphene may also be used. The resistivity of the material is preferably 1×10 5 Ω·cm or less, more preferably 1×10 4 Ω·cm or less.

[0256] Alternatively, one or both of the first electrode 101 and the second electrode 102 may be formed by stacking a plurality of the above materials.

[0257] Furthermore, in order to improve light extraction efficiency, a material having a higher refractive index than an electrode having a light-transmitting function may be formed in contact with the electrode. Such a material may be any material that transmits visible light, and may or may not be conductive. Examples of such a material include oxide semiconductors and organic materials, as well as the oxide conductors described above. Examples of organic materials include the materials exemplified for the light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer. Inorganic carbon-based materials or thin metal films that transmit light may also be used, and multiple layers of several nanometers to several tens of nanometers thick may be stacked.

[0258] When the first electrode 101 or the second electrode 102 functions as a cathode, it is preferable that the electrode be made of a material with a small work function (3.8 eV or less). For example, elements belonging to Group 1 or 2 of the periodic table (alkali metals such as lithium, sodium, and cesium, alkaline earth metals such as calcium and strontium, magnesium, etc.), alloys containing these elements (e.g., Ag and Mg, Al and Li), rare earth metals such as europium (Eu) and Yb, alloys containing these rare earth metals, alloys containing aluminum and silver, etc. can be used.

[0259] When the first electrode 101 or the second electrode 102 is used as an anode, it is preferable to use a material with a large work function (4.0 eV or more).

[0260] The first electrode 101 and the second electrode 102 may be a laminate of a conductive material having a light-reflecting function and a conductive material having a light-transmitting function. In this case, the first electrode 101 and the second electrode 102 are preferable because they can adjust the optical path so that light of a desired wavelength from each light-emitting layer can be resonated and the light of that wavelength can be intensified.

[0261] The first electrode 101 and the second electrode 102 can be formed by any suitable method, such as sputtering, vapor deposition, printing, coating, MBE (Molecular Beam Epitaxy), CVD (Chemical Vapor Deposition), pulsed laser deposition, or ALD (Atomic Layer Deposition).

[0262] <Charge generation layer> The charge generation layer 106 has a function of injecting electrons into the organic compound layer 103a and injecting holes into the organic compound layer 103b when a voltage is applied between the first electrode (anode) 101 and the second electrode (cathode) 102. The charge generation layer 106 may be a layer in which an electron acceptor is added to a hole transport material (also referred to as a P-type layer) or an electron donor is added to an electron transport material (also referred to as an electron injection buffer layer). Alternatively, both of these layers may be stacked. Furthermore, an electron relay layer may be provided between the P-type layer and the electron injection buffer layer. Forming the charge generation layer 106 using the above-mentioned materials can suppress an increase in driving voltage when an EL layer is stacked.

[0263] When the charge generation layer 106 has a structure in which an electron acceptor is added to a hole-transporting material that is an organic compound (a P-type layer), the material described in this embodiment can be used as the hole-transporting material. Examples of the electron acceptor include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ) and chloranil. Examples of the electron acceptor include oxides of metals that belong to Groups 4 to 8 of the periodic table. Specific examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. The acceptor materials described above may also be used. Materials for the P-type layer may be mixed together to form a mixed film, or single films containing each material may be stacked.

[0264] When the charge generation layer 106 has a structure in which an electron donor is added to an electron transporting material (electron injection buffer layer), the material described in this embodiment can be used as the electron transporting material. The electron donor can be an alkali metal, an alkaline earth metal, a rare earth metal, or a metal belonging to Groups 2 and 13 of the periodic table, or an oxide or carbonate thereof. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide (LiO), cesium carbonate, or the like is preferably used. An organic compound such as tetrathianaphthacene can also be used as the electron donor.

[0265] When an electron relay layer is provided between the P-type layer and the electron injection buffer layer in the charge generation layer 106, the electron relay layer contains at least a substance having electron transport properties and functions to prevent interaction between the electron injection buffer layer and the P-type layer and smoothly transfer electrons. The LUMO level of the electron-transporting substance contained in the electron relay layer is preferably between the LUMO level of the acceptor substance in the P-type layer and the LUMO level of the electron-transporting substance contained in the electron transport layer in contact with the charge generation layer 106. The specific energy level of the LUMO level of the electron-transporting substance used in the electron relay layer is −5.0 eV or higher, preferably −5.0 eV or higher to −3.0 eV or lower, more preferably −4.30 eV or higher to −3.00 eV or lower, and more preferably −4.30 eV or higher to −3.30 eV or lower. Note that the electron-transporting substance used in the electron relay layer is preferably a phthalocyanine-based material or an organometallic complex having a metal-oxygen bond and an aromatic ligand.

[0266] Specifically, organic compounds that can be used in the electron relay layer include alkylamine skeletons with 1 to 6 carbon atoms. Specific examples include organic compounds having basic skeletons, such as acetamidine skeletons, guanidine skeletons, and pyrrolidine skeletons, represented by the following structural formulas (401) to (404). Structural formulas (403) and (404), which have guanidine skeletons, are particularly preferred due to their high basicity. Furthermore, these organic compounds having alkylamine skeletons preferably have electron-transporting properties as a substituent, and preferably have at least one of an aromatic hydrocarbon skeleton, a π-electron-deficient heteroaromatic ring skeleton, and a nitrogen-containing heteroaromatic skeleton. Specific examples include a benzene skeleton, a fluorene skeleton, a naphthalene skeleton, an anthracene skeleton, a phenanthrene skeleton, a triphenylene skeleton, a pyrene skeleton, a polyazole skeleton, a pyridine skeleton, a pyrimidine skeleton, a pyrazine skeleton, a diazine skeleton, a triazine skeleton, a quinoline skeleton, a quinazoline skeleton, a quinoxaline skeleton, a phenanthroline skeleton, and a dibenzoquinoxaline skeleton.

[0267] [ka]

[0268] Specifically, the organic compound is preferably an organic compound having a bicyclo ring structure having two or more nitrogen atoms in the ring, and a heteroaromatic ring having 2 to 30 carbon atoms in the ring or an aromatic hydrocarbon ring having 6 to 30 carbon atoms in the ring, more specifically, 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 in the ring or an aromatic hydrocarbon ring having 6 to 30 carbon atoms in the ring. Note that the organic compound is more preferably an organic compound having a bicyclo ring structure having two or more nitrogen atoms in the ring, and a heteroaromatic ring having 2 to 30 carbon atoms in the ring, more specifically, 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 in the ring. Further, organic compounds having a guanidine skeleton are preferred, and organic compounds having a molecular structure in which a bicyclo ring structure having two or more nitrogen atoms as ring-constituting elements contains a guanidine skeleton are more preferred.

[0269] More specifically, it is preferably an organic compound represented by the following general formula (R1).

[0270] [ka]

[0271] In the organic compound represented by the general formula (R1), X is a group represented by the following general formula (R1-1), and Y is a group represented by the following general formula (R1-2). 401 and R 402 each independently represents hydrogen (including deuterium), h represents an integer of 1 to 6, and Ar represents a substituted or unsubstituted heteroaromatic ring having 2 to 30 carbon atoms forming the ring or an aromatic hydrocarbon ring having 6 to 30 carbon atoms forming the ring. Ar is preferably a substituted or unsubstituted heteroaromatic ring having 2 to 30 carbon atoms forming the ring.

[0272] Furthermore, by setting h to an integer of 1 or 2, an organic compound with good sublimability can be provided.

[0273] Furthermore, Ar preferably has one or more of an aromatic ring skeleton, a π-electron-deficient heteroaromatic ring skeleton, or a nitrogen-containing heteroaromatic skeleton. Specifically, a substituent having a benzene skeleton, a naphthalene skeleton, an anthracene skeleton, a phenanthrene skeleton, a polyazole skeleton, a pyridine skeleton, a pyrimidine skeleton, a pyrazine skeleton, a diazine skeleton, a triazine skeleton, a quinoline skeleton, a quinazoline skeleton, a quinoxaline skeleton, a phenanthroline skeleton, or a dibenzoquinoxaline skeleton is preferred.

[0274] [ka]

[0275] However, in the above general formulas (R1-1) and (R1-2), R 403 ~R 406 each independently represents hydrogen (including deuterium), m represents an integer of 0 to 4, n represents an integer of 1 to 5, and m+1≧n. When m or n is 2 or more, a plurality of R 403 ~R 406 may be the same or different. When m is 0, carbon (C) and nitrogen (N) are preferably bonded together in the above general formula (R1).

[0276] The organic compound represented by the general formula (R1) above is preferably any one of the following general formulae (R2-1) to (R2-6).

[0277] [ka]

[0278] However, R 411 ~R 426each independently represents hydrogen (including deuterium), h represents an integer of 1 to 6, and Ar represents a substituted or unsubstituted heteroaromatic ring having 2 to 30 carbon atoms forming a ring or an aromatic hydrocarbon ring having 6 to 30 carbon atoms forming a ring. Ar is preferably a substituted or unsubstituted heteroaromatic ring having 2 to 30 carbon atoms forming a ring.

[0279] In the above general formula (R1) and general formulas (R2-1) to (R2-6), specific examples of the substituted or unsubstituted heteroaromatic ring represented by Ar having 2 to 30 carbon atoms forming a ring or the aromatic hydrocarbon ring having 6 to 30 carbon atoms forming a ring include 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 di ... Examples of the ring include a benzofuran ring, a benzonaphthofuran ring, a dinaphthofuran ring, a dibenzothiophene ring, a benzonaphthothiophene ring, a dinaphthothiophene ring, a benzofuropyridine ring, a benzofuropyrimidine ring, a benzothiopyridine ring, a benzothiopyrimidine ring, a naphthofuropyridine ring, a naphthofuropyrimidine ring, a naphthothiopyridine ring, a naphthothiopyrimidine ring, an acridine ring, a 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, and a pyrrole ring. In the above general formula (R1) and general formulas (R2-1) to (R2-6), examples of the substituted or unsubstituted aromatic hydrocarbon ring having 6 to 30 carbon atoms and represented by Ar include 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, a chrysene ring, and a benzo[a]anthracene ring. Among these, any one of the following structural formulas (Ar-401) to (Ar-427) is preferable.

[0280] [ka]

[0281] It is preferable that the Ar contains nitrogen as an element constituting a ring, and that the Ar is bonded to the skeleton in the parentheses in the general formula (R1) via a bond to the nitrogen or a bond to a carbon adjacent to the nitrogen.

[0282] Specific examples of the organic compounds represented by the general formula (R1) and the general formulas (R2-1) to (R2-6) include organic compounds represented by the following structural formulas (405) to (424).

[0283] [ka]

[0284] Although FIG. 1D shows a structure in which two organic compound layers 103 are stacked, a stack structure of three or more organic compound layers may be used by providing a charge generation layer between different organic compound layers.

[0285] <Substrate> The light-emitting element according to one embodiment of the present invention may be fabricated over a substrate made of glass, plastic, or the like. The order of fabrication on the substrate may be from the first electrode 101 side or from the second electrode 102 side.

[0286] Note that, as a substrate on which a light-emitting element according to one embodiment of the present invention can be formed, for example, glass, quartz, or plastic can be used. A flexible substrate may also be used. A flexible substrate is a bendable (flexible) substrate, and examples thereof include a plastic substrate made of polycarbonate or polyarylate. A film, an inorganic vapor-deposited film, or the like can also be used. Note that other materials may be used as long as they function as a support in the manufacturing process of the light-emitting element and the optical element. Alternatively, any material may be used as long as it has a function of protecting the light-emitting element and the optical element.

[0287] For example, in this specification, various substrates can be used to form light-emitting elements. The type of substrate is not particularly limited. Examples of such substrates include semiconductor substrates (e.g., single-crystal substrates or silicon substrates), SOI (Silicon-on-Insulator) substrates, glass substrates, quartz substrates, plastic substrates, metal substrates, stainless steel substrates, substrates with stainless steel foil, tungsten substrates, substrates with tungsten foil, flexible substrates, laminated films, cellulose nanofibers (CNF) containing fibrous materials, paper, and base films. Examples of glass substrates include barium borosilicate glass, aluminoborosilicate glass, and soda-lime glass. Examples of flexible substrates, laminated films, and base films include the following: Plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), and polytetrafluoroethylene (PTFE) are typical examples. Another example is acrylic resin. Other examples include polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, etc. Other examples include resins such as polyamide, polyimide, aramid, or epoxy, inorganic vapor deposition films, and papers.

[0288] Alternatively, a flexible substrate may be used as the substrate, and the light-emitting element may be formed directly on the flexible substrate. Alternatively, a release layer may be provided between the substrate and the light-emitting element. The release layer can be used to separate the light-emitting element from the substrate after completing a part or all of the light-emitting element thereon and transfer it to another substrate. In this case, the light-emitting element can be transferred to a substrate with poor heat resistance or a flexible substrate. The release layer may be, for example, a laminated structure of inorganic films such as a tungsten film and a silicon oxide film, or a structure in which a resin film such as polyimide is formed on a substrate.

[0289] That is, a light-emitting element may be formed using a certain substrate, and then the light-emitting element may be transferred to another substrate, and the light-emitting element may be disposed on the other substrate. In addition to the above-mentioned substrates, examples of the substrate onto which the light-emitting element may be transferred include a cellophane substrate, a stone substrate, a wood substrate, a cloth substrate (including natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester), or recycled fibers (acetate, cupra, rayon, recycled polyester)), a leather substrate, or a rubber substrate. By using these substrates, a light-emitting element that is durable, highly heat-resistant, lightweight, or thin can be obtained.

[0290] Alternatively, a field effect transistor (FET) may be formed on the substrate, and a light-emitting device may be fabricated on an electrode electrically connected to the FET. This allows fabrication of an active matrix display device in which the FET controls the driving of the light-emitting device.

[0291] Note that one embodiment of the present invention has been described in this embodiment. Alternatively, another embodiment of the present invention will be described. However, one embodiment of the present invention is not limited thereto. That is, various embodiments of the present invention are described in this embodiment and the other embodiments, and therefore one embodiment of the present invention is not limited to a specific embodiment. For example, although an example in which the present invention is applied to a light-emitting element has been described as one embodiment of the present invention, one embodiment of the present invention is not limited thereto. For example, depending on the circumstances or the situation, one embodiment of the present invention does not need to be applied to a light-emitting element. Alternatively, for example, one embodiment of the present invention includes a first organic compound, a second organic compound, and a guest material capable of converting triplet excitation energy into light emission, and the LUMO level of the first organic compound is lower than that of the second organic compound, and the HOMO level of the first organic compound is lower than that of the second organic compound. However, one embodiment of the present invention is not limited thereto. Depending on the circumstances or the situation, in one embodiment of the present invention, for example, the LUMO level of the first organic compound does not need to be lower than that of the second organic compound. Alternatively, the HOMO level of the first organic compound does not have to be lower than the HOMO level of the second organic compound. Alternatively, for example, in one embodiment of the present invention, the first organic compound and the second organic compound form an exciplex. However, this embodiment is not limited to this example. Depending on the circumstances, or depending on the situation, in one embodiment of the present invention, the first organic compound and the second organic compound do not have to form an exciplex. Alternatively, for example, in one embodiment of the present invention, the LUMO level of the guest material is higher than the LUMO level of the first organic compound and lower than the HOMO level of the second organic compound. However, this embodiment is not limited to this example. Depending on the circumstances, or depending on the situation, in one embodiment of the present invention, the LUMO level of the guest material does not have to be higher than the LUMO level of the first organic compound. Alternatively, the HOMO level of the guest material does not have to be lower than the HOMO level of the second organic compound.

[0292] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0293] (Embodiment 3) 2A and 2B, a light-emitting device is formed by forming a plurality of light-emitting devices described in the above embodiment over an insulating layer 175. In this embodiment, a light-emitting device according to one embodiment of the present invention will be described in detail.

[0294] The light emitting device 1000 has a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. The pixel 178 has a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0295] In this specification and the like, matters common to, for example, the subpixel 110R, the subpixel 110G, and the subpixel 110B may be described by referring to the subpixel 110. Furthermore, for components distinguished by alphabets, matters common to the corresponding structures may be described using symbols without the alphabets.

[0296] The subpixel 110R emits red light, the subpixel 110G emits green light, and the subpixel 110B emits blue light. This allows an image to be displayed in the pixel unit 177. Note that in this embodiment, subpixels of three colors, red (R), green (G), and blue (B), are described as an example, but the present invention is not limited to this configuration. That is, combinations of subpixels of other colors may also be used. For example, the number of subpixels is not limited to three, and may be four or more. Examples of four subpixels include subpixels of four colors: R, G, B, and white (W); subpixels of four colors: R, G, B, and yellow (Y); and subpixels of R, G, B, and infrared (IR).

[0297] In this specification, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0298] 2A shows an example in which sub-pixels of different colors are arranged side by side in the X direction, and sub-pixels of the same color are arranged side by side in the Y direction. Note that sub-pixels of different colors may also be arranged side by side in the Y direction, and sub-pixels of the same color may also be arranged side by side in the X direction.

[0299] A connection portion 140 and a region 141 may be provided outside the pixel portion 177. For example, the region 141 may be provided between the pixel portion 177 and the connection portion 140. An organic compound layer 103 is provided in the region 141. In addition, a conductive layer 151C is provided in the connection portion 140.

[0300] 2A shows an example in which the region 141 and the connection portion 140 are located on the right side of the pixel portion 177, but the positions of the region 141 and the connection portion 140 are not particularly limited. The region 141 and the connection portion 140 may be singular or plural.

[0301] 2(B) is an example of a cross-sectional view taken along dashed line A1-A2 in FIG. 2(A). As shown in FIG. 2(B), the light-emitting device 1000 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and on the conductive layer 172, an insulating layer 174 on the insulating layer 173, and an insulating layer 175 on the insulating layer 174. The insulating layer 171 may be provided on a substrate (not shown). The insulating layer 175, the insulating layer 174, and the insulating layer 173 have openings that reach the conductive layer 172, and a plug 176 is provided to fill the opening.

[0302] In the pixel section 177, the light emitting device 130 is provided on the insulating layer 175 and the plug 176. Furthermore, the substrate 120 is bonded to the light emitting device 130 by a resin layer 122. Furthermore, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 may be provided between adjacent light emitting devices 130.

[0303] 2B shows multiple cross sections of the inorganic insulating layer 125 and the insulating layer 127, it is preferable that the inorganic insulating layer 125 and the insulating layer 127 are connected to one another when the light-emitting device 1000 is viewed from above. That is, it is preferable that the inorganic insulating layer 125 and the insulating layer 127 have openings over the first electrodes.

[0304] 2(B) shows light emitting device 130R, light emitting device 130G, and light emitting device 130B. Light emitting device 130R, light emitting device 130G, and light emitting device 130B emit light of different colors. For example, light emitting device 130R can emit red light, light emitting device 130G can emit green light, and light emitting device 130B can emit blue light. Light emitting device 130R, light emitting device 130G, or light emitting device 130B may also emit other visible light or infrared light.

[0305] The organic compound layer 103 has at least a light-emitting layer, and may have other functional layers (such as a hole injection layer, a hole transport layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron injection layer). The organic compound layer 103 and the common layer 104 may be combined to form functional layers (such as a hole injection layer, a hole transport layer, a hole blocking layer, a light-emitting layer, an electron blocking layer, an electron transport layer, and an electron injection layer) that are included in an EL layer that emits light.

[0306] The light-emitting device of one embodiment of the present invention can be, for example, a top-emission type that emits light in the direction opposite to the substrate on which the light-emitting device is formed. Note that the light-emitting device of one embodiment of the present invention may also be a bottom-emission type.

[0307] Here, the light-emitting device 130 (light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B) has the configuration as shown in Embodiment 1. The light-emitting device 130 includes a first electrode (pixel electrode) composed of a conductive layer 151 (conductive layer 151R, conductive layer 151G, conductive layer 151B) and a conductive layer 152 (conductive layer 152R, conductive layer 152G, conductive layer 152B), an organic compound layer 103 (organic compound layer 103B, organic compound layer 103G, and organic compound layer 103B) on the first electrode, a common layer 104 on the organic compound layer 103, a second electrode (common electrode) 102 on the common layer, and a cap layer 131.

[0308] The common layer 104 is not necessarily provided. By providing the common layer 104, damage to the organic compound layer 103 in a later process can be reduced. When the common layer 104 is provided, the common layer 104 may also function as an electron injection layer. When the common layer 104 functions as an electron injection layer, the stacked structure of the organic compound layer 103 and the common layer 104 corresponds to the organic compound layer 103 in Embodiment 1.

[0309] One of the pixel electrode and the common electrode of the light-emitting device functions as an anode and the other functions as a cathode. In the following description, unless otherwise specified, the pixel electrode functions as an anode and the common electrode functions as a cathode.

[0310] The organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are independent island-shaped layers, each for each light-emitting color. By providing the organic compound layer 103 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-resolution light-emitting device. This makes it possible to prevent crosstalk and realize a light-emitting device with extremely high contrast. In particular, a light-emitting device with high current efficiency at low luminance can be realized.

[0311] The organic compound layer 103 may be provided so as to cover the top and side surfaces of the first electrode (pixel electrode) of the light-emitting device 130. This makes it easier to increase the aperture ratio of the light-emitting device 1000 compared to a configuration in which the end of the organic compound layer 103 is located inside the end of the pixel electrode. Furthermore, covering the side surfaces of the pixel electrode of the light-emitting device 130 with the organic compound layer 103 prevents the pixel electrode from contacting the second electrode 102, thereby preventing short circuits in the light-emitting device 130. Furthermore, the distance between the light-emitting region of the organic compound layer 103 (i.e., the region overlapping with the pixel electrode) and the end of the organic compound layer 103 can be increased. Furthermore, since the end of the organic compound layer 103 may be damaged by processing, using a region away from the end of the organic compound layer 103 as the light-emitting region improves the reliability of the light-emitting device 130.

[0312] In the light-emitting device of one embodiment of the present invention, the first electrode (pixel electrode) of the light-emitting device may have a stacked-layer structure. For example, in the example shown in FIG. 2B, the first electrode of the light-emitting device 130 has a stacked-layer structure of a conductive layer 151 and a conductive layer 152.

[0313] For example, when the light-emitting device 1000 is a top-emission type, the pixel electrode of the light-emitting device 130 preferably has a conductive layer 151 with high reflectivity for visible light and a conductive layer 152 that is transparent to visible light and has a high work function. The higher the reflectivity of the pixel electrode for visible light, the higher the extraction efficiency of light emitted from the organic compound layer 103. Furthermore, when the pixel electrode functions as an anode, the higher the work function of the pixel electrode, the easier it is to inject holes into the organic compound layer 103. Therefore, by forming the pixel electrode of the light-emitting device 130 into a stacked structure of the conductive layer 151 with high reflectivity for visible light and the conductive layer 152 with a high work function, the light-emitting device 130 can be a light-emitting device with high light extraction efficiency and low driving voltage.

[0314] Specifically, the reflectance of the conductive layer 151 to visible light is, for example, 40% to 100%, preferably 70% to 100%. When the conductive layer 152 is used as an electrode that is transparent to visible light, it is preferable that the transmittance of the conductive layer 152 to visible light is, for example, 40% or more.

[0315] Furthermore, when a film formed after forming a pixel electrode having a laminated structure is removed by a wet etching method or the like, the chemical solution used for etching may permeate the structure including the pixel electrode. If the impregnated chemical solution comes into contact with the pixel electrode, galvanic corrosion or the like may occur between the multiple layers that make up the pixel electrode, which may cause deterioration of the pixel electrode.

[0316] Therefore, it is preferable to form the conductive layer 152 so as to cover the upper surface and side surfaces of the conductive layer 151. By covering the conductive layer 151 with the conductive layer 152, the impregnated chemical solution does not come into contact with the conductive layer 151, and the occurrence of galvanic corrosion in the pixel electrode can be suppressed. Therefore, the light-emitting device 1000 can be manufactured by a method with a high yield, and therefore can be a low-cost light-emitting device. Furthermore, since the occurrence of defects in the light-emitting device 1000 can be suppressed, the light-emitting device 1000 can be a highly reliable light-emitting device.

[0317] For example, a metal material can be used for the conductive layer 151. Specifically, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), etc., and alloys containing appropriate combinations of these metals can also be used.

[0318] The conductive layer 152 can be formed using an oxide containing one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon. For example, it is preferable to use a conductive oxide containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon. In particular, indium tin oxide containing silicon has a large work function, for example, a work function of 4.0 eV or more, and therefore can be suitably used for the conductive layer 152.

[0319] The conductive layer 151 and the conductive layer 152 may have a stacked structure of multiple layers containing different materials. In this case, the conductive layer 151 may include a layer containing a material that can be used for the conductive layer 152, such as a conductive oxide, or the conductive layer 152 may include a layer containing 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 can be a layer containing the same material as the layer of the conductive layer 152 in contact with the conductive layer 151.

[0320] Note that the conductive layer 151 preferably has a tapered edge. Specifically, the conductive layer 151 preferably has a tapered edge with a taper angle of less than 90°. In this case, the conductive layer 152 provided along the side surface of the conductive layer 151 also has a tapered edge. By tapering the edge of the conductive layer 152, coverage of the organic compound layer 103 provided along the side surface of the conductive layer 152 can be improved.

[0321] When the conductive layer 151 or the conductive layer 152 has a layered structure, at least one side surface thereof preferably has a tapered shape. In addition, in the layered structure constituting each conductive layer, each layer may have a different tapered shape.

[0322] 3A shows a case where the conductive layer 151 has a stacked structure of multiple layers containing different materials. As shown in FIG. 3A, the conductive layer 151 has a structure including a conductive layer 151_1, a conductive layer 151_2 on the conductive layer 151_1, and a conductive layer 151_3 on the conductive layer 151_2. That is, the conductive layer 151 shown in FIG. 3A has a three-layer stacked structure. In this way, when the conductive layer 151 has a stacked structure of multiple layers, the reflectivity of at least one layer constituting the conductive layer 151 to visible light should be higher than the reflectivity of the conductive layer 152 to visible light.

[0323] 3A, the conductive layer 151_2 is sandwiched between the conductive layer 151_1 and the conductive layer 151_3. The conductive layer 151_1 and the conductive layer 151_3 are preferably made of a material that is less likely to change in quality than the conductive layer 151_2. For example, the conductive layer 151_1 can be made of a material that is less likely to cause migration due to contact with the insulating layer 175 than the conductive layer 151_2. The conductive layer 151_3 can be made of a material that is less likely to oxidize than the conductive layer 151_2 and has an oxide with lower electrical resistivity than the oxide of the material used for the conductive layer 151_2.

[0324] As described above, by sandwiching the conductive layer 151_2 between the conductive layer 151_1 and the conductive layer 151_3, the range of material options for the conductive layer 151_2 can be expanded. This allows the conductive layer 151_2 to have a higher reflectivity for visible light than at least one of the conductive layer 151_1 and the conductive layer 151_3. For example, aluminum can be used for the conductive layer 151_2. Note that an alloy containing aluminum may be used for the conductive layer 151_2. Furthermore, titanium, which has a lower reflectivity for visible light than aluminum but is less likely to migrate than aluminum even when in contact with the insulating layer 175, can be used for the conductive layer 151_1. Furthermore, titanium, which has a lower reflectivity for visible light than aluminum but is less likely to oxidize than aluminum and has an oxide with lower electrical resistivity than aluminum oxide, can be used for the conductive layer 151_3.

[0325] Alternatively, the conductive layer 151_3 may be made of silver or an alloy containing silver. Silver has a higher reflectivity to visible light than titanium. Furthermore, silver is less susceptible to oxidation than aluminum, and the electrical resistivity of silver oxide is lower than that of aluminum oxide. Therefore, using silver or an alloy containing silver for the conductive layer 151_3 can favorably increase the reflectivity of the conductive layer 151 to visible light while suppressing an increase in the electrical resistance of the pixel electrode due to oxidation of the conductive layer 151_2. An example of an alloy containing silver is an alloy of silver, palladium, and copper (Ag-Pd-Cu, also referred to as APC). Using silver or an alloy containing silver for the conductive layer 151_3 and aluminum for the conductive layer 151_2 can increase the reflectivity of the conductive layer 151_3 to visible light compared to the reflectivity of the conductive layer 151_2. The conductive layer 151_2 may be made of silver or an alloy containing silver. Alternatively, the conductive layer 151_1 may be made of silver or an alloy containing silver.

[0326] On the other hand, a film using titanium has better etching processability than a film using silver. Therefore, by using titanium for the conductive layer 151_3, the conductive layer 151_3 can be easily formed. Note that a film using aluminum also has better etching processability than a film using silver.

[0327] As described above, the characteristics of the light-emitting device can be improved by forming the conductive layer 151 with a stacked structure of multiple layers. For example, the light-emitting device 1000 can have high light extraction efficiency and high reliability.

[0328] Here, when a microcavity structure is applied to the light-emitting device 130, the light extraction efficiency of the light-emitting device 1000 can be suitably improved by using silver or an alloy containing silver, which is a material with high reflectivity for visible light, as the conductive layer 151_3.

[0329] 3A, depending on the material selection or processing method of the conductive layer 151, the side surface of the conductive layer 151_2 may be located inside the side surfaces of the conductive layer 151_1 and the conductive layer 151_3, forming a protruding portion, which may reduce the coverage of the conductive layer 152 with respect to the conductive layer 151, and may cause a step disconnection of the conductive layer 152.

[0330] Therefore, it is preferable to provide an insulating layer 156 as shown in Fig. 3A. Fig. 3A shows an example in which the insulating layer 156 is provided over the conductive layer 151_1 so as to have a region overlapping with the side surface of the conductive layer 151_2. This can prevent the conductive layer 152 from being broken or thinned due to the protrusion, thereby suppressing poor connection or an increase in driving voltage.

[0331] 3A illustrates a structure in which the side surfaces of the conductive layer 151_2 are entirely covered with the insulating layer 156, but the side surfaces of the conductive layer 151_2 may not be partially covered with the insulating layer 156. Similarly, in pixel electrodes having structures to be described later, the side surfaces of the conductive layer 151_2 may not be partially covered with the insulating layer 156.

[0332] 3A, the insulating layer 156 preferably has a curved surface. This can prevent discontinuities in the conductive layer 152 covering the insulating layer 156, compared to when the side surfaces of the insulating layer 156 are vertical (parallel to the Z direction). Even when the insulating layer 156 has a tapered side surface, specifically a tapered shape with a taper angle of less than 90°, the occurrence of discontinuities in the conductive layer 152 covering the insulating layer 156 can be prevented, compared to when the side surfaces of the insulating layer 156 are vertical. As described above, the light-emitting device 1000 can be manufactured by a method with a high yield. Furthermore, the occurrence of defects can be prevented, and the light-emitting device 1000 can be a highly reliable light-emitting device.

[0333] Note that one embodiment of the present invention is not limited to this. For example, other structures of the first electrode 101 are shown in FIGS.

[0334] FIG. 3B shows a structure in which the insulating layer 156 covers not only the side surface of the conductive layer 151_2 but also the side surfaces of the conductive layers 151_1, 151_2, and 151_3 in the first electrode 101 of FIG.

[0335] FIG. 3C shows a structure in which the insulating layer 156 is not provided in the first electrode 101 of FIG.

[0336] FIG. 3D shows a structure in which the conductive layer 151 does not have a layered structure and the conductive layer 152 has a layered structure in the first electrode 101 of FIG.

[0337] The conductive layer 152_1 has higher adhesion to the conductive layer 152_2 than the insulating layer 175, for example. The conductive layer 152_1 can be formed using an oxide containing one or more of indium, tin, zinc, gallium, titanium, aluminum, and silicon. For example, a conductive oxide containing one or more of indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, zinc oxide containing gallium, titanium oxide, indium titanium oxide, zinc titanate, aluminum zinc oxide, indium zinc oxide containing gallium, indium zinc oxide containing aluminum, indium tin oxide containing silicon, and indium zinc oxide containing silicon can be preferably used. This can prevent peeling of the conductive layer 152_2. The conductive layer 152_2 can be prevented from being in contact with the insulating layer 175.

[0338] The conductive layer 152_2 has a higher reflectance to visible light (for example, reflectance to light with a predetermined wavelength in the range of 400 nm to 750 nm) than the conductive layers 151, 152_1, and 152_3. The reflectance of the conductive layer 152_2 to visible light can be, for example, 70% to 100%, preferably 80% to 100%, and more preferably 90% to 100%. For example, the conductive layer 152_2 can be made of silver or an alloy containing silver. An example of an alloy containing silver is an alloy of silver, palladium, and copper (APC). As described above, the light-emitting device 1000 can have high light extraction efficiency. Note that a metal other than silver may be used for the conductive layer 152_2.

[0339] When the conductive layer 151 and the conductive layer 152 function as anodes, the conductive layer 152_3 preferably has a high work function. For example, the conductive layer 152_3 has a higher work function than the conductive layer 152_2. For example, the conductive layer 152_3 can be made of the same material as the conductive layer 152_1. For example, the conductive layer 152_1 and the conductive layer 152_3 can be made of the same material.

[0340] Note that when the conductive layers 151 and 152 function as cathodes, the conductive layer 152_3 preferably has a low work function, for example, a work function lower than that of the conductive layer 152_2.

[0341] The conductive layer 152_3 is preferably a layer having high transmittance to visible light (for example, transmittance to light with a predetermined wavelength in the range of 400 nm to less than 750 nm). For example, the transmittance of the conductive layer 152_3 to visible light is preferably higher than that of the conductive layer 151 and the conductive layer 152_2. For example, the transmittance of the conductive layer 152_3 to visible light can be 60% to 100%, preferably 70% to 100%, and more preferably 80% to 100%. As a result, the amount of light emitted from the organic compound layer 103 that is absorbed by the conductive layer 152_3 can be reduced. As described above, the conductive layer 152_2 below the conductive layer 152_3 can be a layer having high reflectance to visible light. Therefore, the light-emitting device 1000 can have high light extraction efficiency.

[0342] Next, an example of a method for manufacturing the light emitting device 1000 having the structure shown in FIG. 2 will be described with reference to FIGS.

[0343] [Production method example 1] Thin films (insulating films, semiconductor films, conductive films, etc.) that make up light-emitting devices can be formed using methods such as sputtering, chemical vapor deposition, vacuum evaporation, pulsed laser deposition (PLD), or ALD. CVD methods include plasma enhanced chemical vapor deposition (PECVD) and thermal CVD. One type of thermal CVD method is metal organic chemical vapor deposition (MOCVD).

[0344] Furthermore, thin films (insulating films, semiconductor films, conductive films, etc.) constituting the light-emitting device can be formed by wet film formation methods such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0345] In particular, vacuum processes such as vapor deposition and solution processes such as spin coating and inkjet printing can be used to fabricate light-emitting devices. Vapor deposition methods include physical vapor deposition (PVD) methods such as sputtering, ion plating, ion beam deposition, molecular beam deposition, and vacuum deposition, and chemical vapor deposition (CVD). In particular, functional layers included in the organic compound layer (e.g., hole injection layer, hole transport layer, hole blocking layer, light-emitting layer, electron blocking layer, electron transport layer, and electron injection layer) can be formed by vapor deposition (e.g., vacuum deposition), coating methods (e.g., dip coating, die coating, bar coating, spin coating, and spray coating), printing methods (e.g., inkjet printing, screen printing, offset printing, flexography, gravure printing, and microcontact printing), and the like.

[0346] Furthermore, when processing the thin film that constitutes the light-emitting device, it can be processed using, for example, a photolithography method. Alternatively, the thin film may be processed using a nanoimprint method, a sandblasting method, a lift-off method, etc. Furthermore, the island-shaped thin film may be directly formed by a film formation method using a shielding mask such as a metal mask.

[0347] There are two typical photolithography methods: one is to form a resist mask on the thin film to be processed, process the thin film by etching, and then remove the resist mask; the other is to form a photosensitive thin film, and then process the thin film into the desired shape by exposure and development.

[0348] The thin film can be etched by dry etching, wet etching, sandblasting, or the like.

[0349] 4A, an insulating layer 171 is formed on a substrate (not shown). Subsequently, conductive layers 172 and 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 layers 172 and 179. Subsequently, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0350] The substrate may be a substrate having heat resistance sufficient to withstand at least subsequent heat treatment. When an insulating substrate is used, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, an organic resin substrate, or the like may be used. Also, a semiconductor substrate such as a single-crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, or an SOI substrate may be used.

[0351] 4A, openings are formed in the insulating layers 175, 174, and 173, reaching the conductive layer 172. Then, plugs 176 are formed to fill the openings.

[0352] 4A, a conductive film 151f, which will later become the conductive layers 151R, 151G, 151B, and 151C, is formed on the plug 176 and the insulating layer 175. The conductive film 151f can be formed by, for example, sputtering or vacuum evaporation. The conductive film 151f can be made of, for example, a metal material.

[0353] 4A, a resist mask 191 is formed over the conductive film 151f, for example. The resist mask 191 can be formed by applying a photosensitive material (photoresist), exposing it to light, and developing it.

[0354] 4B, the conductive film 151f in a region that does not overlap with the resist mask 191 is removed by, for example, etching, specifically, dry etching. Note that when the conductive film 151f includes a layer using a conductive oxide such as indium tin oxide, the layer may be removed by wet etching. As a result, the conductive layer 151 is formed. Note that when part of the conductive film 151f is removed by dry etching, for example, a recess (also referred to as a countersink) may be formed in a region of the insulating layer 175 that does not overlap with the conductive layer 151.

[0355] 4(C), the resist mask 191 is removed. The resist mask 191 can be removed by ashing using oxygen plasma, for example. Alternatively, oxygen gas and a Group 18 element such as CF4, C4F8, SF6, CHF3, Cl2, HO, BCl3, or He may be used. Alternatively, the resist mask 191 may be removed by wet etching.

[0356] 4(D), an insulating film 156f, which will later become the insulating layers 156R, 156G, 156B, and 156C, is formed on the conductive layers 151R, 151G, 151B, and 151C, and on the insulating layer 175. The insulating film 156f can be formed by, for example, a CVD method, an ALD method, a sputtering method, or a vacuum deposition method.

[0357] The insulating film 156f can be formed using an inorganic material. For example, the insulating film 156f can be formed using an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. For example, the insulating film 156f can be formed using an oxide insulating film containing silicon, a nitride insulating film, an oxynitride insulating film, or a nitride oxide insulating film. For example, the insulating film 156f can be formed using silicon oxynitride.

[0358] 4(E), the insulating film 156f is processed to form insulating layers 156R, 156G, 156B, and 156C. For example, the insulating layer 156 can be formed by uniformly etching the upper surface of the insulating film 156f. Such uniform etching and planarization is also called an etch-back process. The insulating layer 156 may also be formed by photolithography.

[0359] 5A, a conductive film 152f, which will later become the conductive layer 152R, the conductive layer 152G, the conductive layer 152B, and the conductive layer 152C, is formed on the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, the conductive layer 151C, the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, the insulating layer 156C, and the insulating layer 175. Specifically, the conductive film 152f is formed so as to cover, for example, the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, the conductive layer 151C, the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, and the insulating layer 156C.

[0360] The conductive film 152f can be formed by, for example, sputtering or vacuum evaporation. Alternatively, the conductive film 152f can be formed by ALD. Alternatively, the conductive film 152f can be formed using, for example, a conductive oxide. Alternatively, the conductive film 152f can have a stacked structure of a film using a metal material and a film using a conductive oxide on the metal material. For example, the conductive film 152f can have a stacked structure of a film using titanium, silver, or an alloy containing silver and a film using a conductive oxide on the metal material.

[0361] 5(B), the conductive film 152f is processed by, for example, photolithography to form conductive layers 152R, 152G, 152B, and 152C. Specifically, for example, after forming a resist mask, part of the conductive film 152f is removed by etching. The conductive film 152f can be removed by, for example, wet etching. Alternatively, the conductive film 152f may be removed by dry etching. In this manner, a pixel electrode including the conductive layer 151 and the conductive layer 152 is formed.

[0362] Subsequently, it is preferable to perform hydrophobic treatment on the conductive layer 152. The hydrophobic treatment can change the surface to be treated from hydrophilic to hydrophobic, or can increase the hydrophobicity of the surface to be treated. By performing the hydrophobic treatment on the conductive layer 152, adhesion between the conductive layer 152 and the organic compound layer 103 formed in a later step can be improved, and film peeling can be suppressed. Note that the hydrophobic treatment is not necessarily performed.

[0363] 5C, an organic compound film 103Bf, which will later become the organic compound layer 103B, is formed on the conductive layers 152B, 152G, 152R, and the insulating layer 175. Then, as shown in FIG.

[0364] In the present invention, the organic compound film 103Bf has a plurality of organic compound layers each having at least one light-emitting layer. Specifically, the structure of the light-emitting device 130 described in the first embodiment can be referred to. Alternatively, the organic compound film 103Bf may have a structure in which a plurality of organic compound layers each having at least one light-emitting layer are stacked with an intermediate layer interposed therebetween.

[0365] 5C, the organic compound film 103Bf is not formed on the conductive layer 152C. For example, by using a mask for defining the film formation area (also called an area mask or a rough metal mask to distinguish it from a fine metal mask), the organic compound film 103Bf can be formed only in the desired region. By employing a film formation process using an area mask and a processing process using a resist mask, the light-emitting device can be manufactured through a relatively simple process.

[0366] The organic compound film 103Bf can be formed by, for example, a vapor deposition method, specifically a vacuum deposition method, or may be formed by a transfer method, a printing method, an inkjet method, a coating method, or the like.

[0367] Subsequently, as shown in FIG. 5(D), a sacrificial film 158Bf, which will later become the sacrificial layer 158B, and a mask film 159Bf, which will later become the mask layer 159B, are formed in this order on the organic compound film 103Bf.

[0368] The sacrificial film 158Bf and the mask film 159Bf can be formed by, for example, sputtering, ALD (thermal ALD, PEALD), CVD, or vacuum deposition. Alternatively, they may be formed by the wet film formation method described above.

[0369] The sacrificial film 158Bf and the mask film 159Bf are formed at a temperature lower than the heat-resistant temperature of the organic compound film 103Bf. The substrate temperature when forming the sacrificial film 158Bf and the mask film 159Bf is typically 200° C. or lower, preferably 150° C. or lower, more preferably 120° C. or lower, more preferably 100° C. or lower, and even more preferably 80° C. or lower.

[0370] In this embodiment, an example is shown in which the mask film is formed with a two-layer structure of the sacrificial film 158Bf and the mask film 159Bf, but the mask film may have a single-layer structure or a laminated structure of three or more layers.

[0371] By providing a sacrificial layer on the organic compound film 103Bf, damage to the organic compound film 103Bf during the manufacturing process of the light-emitting device can be reduced, and the reliability of the light-emitting device can be improved.

[0372] The sacrificial film 158Bf is made of a film that is highly resistant to the processing conditions of the organic compound film 103Bf, specifically, a film that has a high etching selectivity with respect to the organic compound film 103Bf, and the mask film 159Bf is made of a film that has a high etching selectivity with respect to the sacrificial film 158Bf.

[0373] The sacrificial film 158Bf and the mask film 159Bf are preferably made of films that can be removed by wet etching, which can reduce damage to the organic compound film 103Bf during processing of the sacrificial film 158Bf and the mask film 159Bf compared to when dry etching is used.

[0374] When wet etching is used, it is particularly preferable to use an acidic chemical solution, such as a chemical solution containing one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid, or a mixed chemical solution of two or more acids (also called mixed acid).

[0375] The sacrificial film 158Bf and the mask film 159Bf may each be made of one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, an inorganic insulating film, or the like.

[0376] Furthermore, by using a film containing a material that blocks ultraviolet light for the sacrificial film 158Bf and the mask film 159Bf, it is possible to prevent ultraviolet light from irradiating the organic compound layer during, for example, an exposure process. By preventing the organic compound layer from being damaged by ultraviolet light, the reliability of the light-emitting device can be improved.

[0377] It should be noted that a film containing a material that has a light-shielding property against ultraviolet rays can also achieve the same effect when used as the material for the inorganic insulating film 125f, which will be described later.

[0378] The sacrificial film 158Bf and the mask film 159Bf may be made of a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, or tantalum, or an alloy material containing such a metal material. In particular, it is preferable to use a low-melting-point material such as aluminum or silver.

[0379] Furthermore, the sacrificial film 158Bf and the mask film 159Bf can be made of metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanium oxide (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and indium tin oxide containing silicon, respectively.

[0380] In addition, instead of the above gallium, an element M (M is one or more elements selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium) may be used.

[0381] Furthermore, using semiconductor materials such as silicon or germanium for the sacrificial film 158Bf and the mask film 159Bf is preferable because they have high compatibility with semiconductor manufacturing processes. Oxides or nitrides of the above semiconductor materials can also be used. Non-metallic materials such as carbon or their compounds can also be used. Metals such as titanium, tantalum, tungsten, chromium, and aluminum, or alloys containing one or more of these metals can also be used. Oxides containing the above metals, such as titanium oxide or chromium oxide, or nitrides such as titanium nitride, chromium nitride, or tantalum nitride can also be used.

[0382] Furthermore, various inorganic insulating films can be used for the sacrificial film 158Bf and the mask film 159Bf. In particular, oxide insulating films are preferable because they have higher adhesion to the organic compound film 103Bf than nitride insulating films. For example, inorganic insulating materials such as aluminum oxide, hafnium oxide, and silicon oxide can be used for the sacrificial film 158Bf and the mask film 159Bf. For example, aluminum oxide films can be formed as the sacrificial film 158Bf and the mask film 159Bf using the ALD method. Using the ALD method is preferable because it reduces damage to the underlying layer (especially the organic compound layer).

[0383] Alternatively, an organic material may be used for one or both of the sacrificial film 158Bf and the mask film 159Bf. For example, a material that can be dissolved in a chemically stable solvent may be used as the organic material, at least for the film located at the top of the organic compound film 103Bf. Materials that dissolve in water or alcohol are particularly suitable. When forming a film of such a material, it is preferable to apply the material dissolved in a solvent such as water or alcohol by a wet film formation method, and then perform a heat treatment to evaporate the solvent. Performing the heat treatment under a reduced pressure atmosphere is preferable because it allows the solvent to be removed at a low temperature and in a short time, thereby reducing thermal damage to the organic compound film 103Bf.

[0384] The sacrificial film 158Bf and the mask film 159Bf may each be made of an organic resin such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, alcohol-soluble polyamide resin, or a fluororesin such as a perfluoropolymer.

[0385] For example, the sacrificial film 158Bf may be an organic film (e.g., a PVA film) formed using either a vapor deposition method or one of the above-mentioned wet film formation methods, and the mask film 159Bf may be an inorganic film (e.g., a silicon nitride film) formed using a sputtering method.

[0386] 5(D), a resist mask 190B is formed on the mask film 159Bf. The resist mask 190B can be formed by applying a photosensitive material (photoresist) and then performing exposure and development.

[0387] The resist mask 190B may be made of either a positive resist material or a negative resist material.

[0388] The resist mask 190B is provided in a position overlapping with the conductive layer 152B. The resist mask 190B is preferably also provided in a position overlapping with the conductive layer 152C. This can prevent the conductive layer 152C from being damaged during the manufacturing process of the light-emitting device. Note that the resist mask 190B does not necessarily have to be provided on the conductive layer 152C. Furthermore, as shown in the cross-sectional view between B1 and B2 in FIG. 5C, the resist mask 190B is preferably provided so as to cover from an end of the organic compound film 103Bf to an end of the conductive layer 152C (the end on the organic compound film 103Bf side).

[0389] 5(E), a resist mask 190B is used to remove a portion of the mask film 159Bf to form a mask layer 159B. The mask layer 159B remains on the conductive layer 152B and the conductive layer 152C. The resist mask 190B is then removed. The mask layer 159B is used as a mask (also referred to as a hard mask) to remove a portion of the sacrificial film 158Bf to form a sacrificial layer 158B.

[0390] The sacrificial film 158Bf and the mask film 159Bf can be processed by wet etching or dry etching, respectively, and are preferably processed by wet etching.

[0391] The wet etching method can reduce damage to the organic compound film 103Bf when processing the sacrificial film 158Bf and the mask film 159Bf compared to the dry etching method. When the wet etching method is used, it is preferable to use a chemical solution such as a developer, a tetramethylammonium hydroxide solution (TMAH), diluted hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or a mixture thereof.

[0392] When processing the mask film 159Bf, the organic compound film 103Bf is not exposed, so there is a wider range of processing methods to choose from than when processing the sacrificial film 158Bf. Specifically, even when an oxygen-containing etching gas is used when processing the mask film 159Bf, deterioration of the organic compound film 103Bf can be suppressed.

[0393] When wet etching is used, it is particularly preferable to use an acidic chemical solution, such as a chemical solution containing one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid, or a mixed chemical solution of two or more acids (also called mixed acid).

[0394] Furthermore, when dry etching is used to process the sacrificial film 158Bf, deterioration of the organic compound film 103Bf can be suppressed by not using an oxygen-containing gas as the etching gas. When dry etching is used, it is preferable to use a gas containing a Group 18 element such as CF4, C4F8, SF6, CHF3, Cl2, HO, BCl3, or He as the etching gas.

[0395] The resist mask 190B can be removed in the same manner as the resist mask 191. At this time, the sacrificial film 158Bf is located on the outermost surface and the organic compound film 103Bf is not exposed, so that damage to the organic compound film 103Bf can be suppressed in the process of removing the resist mask 190B. In addition, the range of options for removing the resist mask 190B can be expanded.

[0396] 5(E), the organic compound film 103Bf is processed to form the organic compound layer 103B. For example, the mask layer 159B and the sacrificial layer 158B are used as a hard mask to remove a portion of the organic compound film 103Bf, thereby forming the organic compound layer 103B.

[0397] 5(E), a stacked structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B, and the conductive layers 152G and 152R are exposed.

[0398] The organic compound film 103Bf can be processed by dry etching or wet etching. For example, when processing by dry etching, an etching gas containing oxygen can be used. When the etching gas contains oxygen, the etching rate can be increased. Therefore, etching can be performed under low power conditions while maintaining a sufficiently high etching rate. This can reduce damage to the organic compound film 103Bf. Furthermore, problems such as adhesion of reaction products generated during etching can be reduced.

[0399] Alternatively, an etching gas that does not contain oxygen may be used, for example, by using an etching gas that does not contain oxygen, deterioration of the organic compound film 103Bf can be suppressed.

[0400] As described above, in one embodiment of the present invention, the resist mask 190B is formed over the mask film 159Bf, and part of the mask film 159Bf is removed using the resist mask 190B to form the mask layer 159B. Then, part of the organic compound film 103Bf is removed using the mask layer 159B as a hard mask to form the organic compound layer 103B. Therefore, it can be said that the organic compound layer 103B is formed by processing the organic compound film 103Bf by photolithography. Note that part of the organic compound film 103Bf may be removed using the resist mask 190B. Then, the resist mask 190B may be removed.

[0401] Here, the conductive layer 152G may be subjected to hydrophobic treatment as needed. During processing of the organic compound film 103Bf, for example, the surface state of the conductive layer 152G may change to a hydrophilic state. For example, by subjecting the conductive layer 152G to hydrophobic treatment, for example, adhesion between the conductive layer 152G and a layer (here, the organic compound layer 103G) formed in a later step can be improved, and film peeling can be suppressed.

[0402] 6A, an organic compound film 103Gf, which will later become the organic compound layer 103G, is formed on the conductive layer 152G, the conductive layer 152R, the mask layer 159B, and the insulating layer 175. As shown in FIG.

[0403] The organic compound film 103Gf can be formed by the same method as that used to form the organic compound film 103Bf, and can have the same structure as the organic compound film 103Bf.

[0404] 6(B), a sacrificial film 158Gf, which will later become the sacrificial layer 158G, and a mask film 159Gf, which will later become the mask layer 159G, are sequentially formed on the organic compound film 103Gf and the mask layer 159B. A resist mask 190G is then formed. The materials and formation methods for the sacrificial film 158Gf and the mask film 159Gf are the same as those applicable to the sacrificial film 158Bf and the mask film 159Bf. The materials and formation methods for the resist mask 190G are the same as those applicable to the resist mask 190B.

[0405] The resist mask 190G is provided in a position overlapping with the conductive layer 152G.

[0406] 6(C), a resist mask 190G is used to remove a portion of the mask film 159Gf to form a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. The resist mask 190G is then removed. The mask layer 159G is then used as a mask to remove a portion of the sacrificial film 158Gf to form a sacrificial layer 158G. The organic compound film 103Gf is then processed to form an organic compound layer 103G. For example, the mask layer 159G and the sacrificial layer 158G are used as hard masks to remove a portion of the organic compound film 103Gf to form the organic compound layer 103G.

[0407] 6C, a stacked structure of the organic compound layer 103G, the sacrificial layer 158G, and the mask layer 159G remains on the conductive layer 152G, and the mask layer 159B and the conductive layer 152R are exposed.

[0408] In addition, for example, the conductive layer 152R may be subjected to a hydrophobic treatment.

[0409] Subsequently, as shown in FIG. 7A, an organic compound film 103Rf, which will later become the organic compound layer 103R, is formed on the conductive layer 152R, the mask layer 159G, the mask layer 159B, and the insulating layer 175.

[0410] The organic compound film 103Rf can be formed by the same method as that used to form the organic compound film 103Gf, and can have the same structure as the organic compound film 103Gf.

[0411] 7(B) and 7(C), a resist mask 190R is used to form a sacrificial layer 158R from the sacrificial film 158Rf, a mask layer 159R from the mask film 159Rf, and an organic compound layer 103R from the organic compound film 103Rf. The methods for forming the sacrificial layer 158R, the mask layer 159R, and the organic compound layer 103R can be referred to the description of the organic compound layer 103G.

[0412] It is preferable that the side surfaces of the organic compound layers 103B, 103G, and 103R are perpendicular or substantially perpendicular to the surface on which they are formed. For example, it is preferable that the angle formed between the surface on which they are formed and these side surfaces be 60 degrees or more and 90 degrees or less.

[0413] As described above, the distance between adjacent pairs of the organic compound layers 103B, 103G, and 103R formed using photolithography can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, the distance can be defined, for example, as the distance between the opposing ends of adjacent pairs of the organic compound layers 103B, 103G, and 103R. By narrowing the distance between the island-shaped organic compound layers in this manner, a light-emitting device with high definition and a large aperture ratio can be provided. Furthermore, the distance between the first electrodes of adjacent light-emitting devices can also be narrowed, for example, to 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, or 2 μm or less. It is preferable that the distance between the first electrodes of adjacent light-emitting devices be 2 μm or more and 5 μm or less.

[0414] Next, as shown in FIG. 8(A), the mask layers 159B, 159G, and 159R are removed.

[0415] Although the present embodiment will be described taking as an example a case where the mask layers 159B, 159G, and 159R are removed, the mask layers 159B, 159G, and 159R do not necessarily have to be removed. For example, if the mask layers 159B, 159G, and 159R contain the aforementioned material that has a light-blocking property against ultraviolet light, the organic compound layer can be protected from light irradiation (including illumination light) by proceeding to the next step without removing them.

[0416] The mask layer removal process can be performed using the same method as the mask film processing process. In particular, wet etching can reduce damage to the organic compound layers 103B, 103G, and 103R when removing the mask layer compared to dry etching.

[0417] The mask layer may also be removed by dissolving it in a solvent such as water or alcohol, such as ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0418] After removing the mask layer, a drying treatment may be performed to remove water contained in the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R, as well as water adsorbed on the surfaces of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. For example, a heat treatment can be performed in an inert atmosphere or a reduced-pressure atmosphere. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, and more preferably 70°C or higher and 120°C or lower. A reduced-pressure atmosphere is preferred because it enables drying at a lower temperature.

[0419] Next, as shown in FIG. 8(B), an inorganic insulating film 125f, which will later become the inorganic insulating layer 125, is formed to cover the organic compound layer 103B, the organic compound layer 103G, the organic compound layer 103R, the sacrificial layer 158B, the sacrificial layer 158G, and the sacrificial layer 158R.

[0420] As will be described later, an insulating film that will later become the insulating layer 127 is formed in contact with the upper surface of the inorganic insulating film 125f. For this reason, it is preferable that the upper surface of the inorganic insulating film 125f has a high affinity with the material (e.g., a photosensitive resin composition containing an acrylic resin) used for the insulating film that will become the insulating layer 127. To improve this affinity, a surface treatment may be performed on the upper surface of the inorganic insulating film 125f. Specifically, it is preferable to hydrophobize (or increase the hydrophobicity of) the surface of the inorganic insulating film 125f. For example, it is preferable to perform the treatment using a silylating agent such as hexamethyldisilazane (HMDS). By hydrophobizing the upper surface of the inorganic insulating film 125f in this way, the insulating film 127f can be formed with good adhesion.

[0421] Subsequently, as shown in FIG. 8(C), an insulating film 127f, which will later become the insulating layer 127, is formed on the inorganic insulating film 125f.

[0422] The inorganic insulating film 125f and the insulating film 127f are preferably formed by a formation method that causes less damage to the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. In particular, since the inorganic insulating film 125f is formed in contact with the side surfaces of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R, it is preferably formed by a formation method that causes less damage to the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R than the insulating film 127f.

[0423] The inorganic insulating film 125f and the insulating film 127f are formed at a temperature lower than the heat-resistant temperatures of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R, respectively. By increasing the substrate temperature during film formation, the inorganic insulating film 125f can be formed into a film with a low impurity concentration and a high barrier property against at least one of water and oxygen, even if it is thin.

[0424] The substrate temperature when forming the inorganic insulating film 125f and the insulating film 127f is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0425] As the inorganic insulating film 125f, it is preferable to form an insulating film having a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less within the above substrate temperature range.

[0426] The inorganic insulating film 125f is preferably formed by, for example, the ALD method. The ALD method is preferable because it can reduce film formation damage and also allows for the formation of a film with high coverage. The inorganic insulating film 125f is preferably formed as an aluminum oxide film by, for example, the ALD method.

[0427] Alternatively, the inorganic insulating film 125f may be formed by sputtering, CVD, or PECVD, which have a faster film formation rate than ALD, thereby enabling highly reliable light-emitting devices to be manufactured with high productivity.

[0428] The insulating film 127f is preferably formed by the wet film formation method described above. The insulating film 127f is preferably formed by, for example, spin coating using a photosensitive material, more specifically, using a photosensitive resin composition containing an acrylic resin.

[0429] The insulating film 127f is preferably formed using a resin composition containing, for example, a polymer, an acid generator, and a solvent. The polymer is formed using one or more types of monomers and has a structure in which one or more types of structural units (also referred to as constituent units) are regularly or irregularly repeated. As the acid generator, one or both of a compound that generates an acid when irradiated with light and a compound that generates an acid when heated can be used. The resin composition may further contain one or more of a photosensitizer, a sensitizer, a catalyst, an adhesion aid, a surfactant, and an antioxidant.

[0430] Furthermore, heat treatment (also referred to as pre-baking) is preferably performed after the insulating film 127f is formed. The heat treatment is performed at a temperature lower than the heat resistance temperature of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. The substrate temperature during the heat treatment is preferably 50° C. to 200° C., more preferably 60° C. to 150° C., and still more preferably 70° C. to 120° C. This allows the solvent contained in the insulating film 127f to be removed.

[0431] Next, exposure is performed to expose a portion of the insulating film 127f to visible light or ultraviolet light. If a positive-type photosensitive resin composition containing an acrylic resin is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 will not be formed in a later process. The insulating layer 127 is formed in the region sandwiched between any two of the conductive layers 152B, 152G, and 152R, and around the conductive layer 152C. Therefore, visible light or ultraviolet light is irradiated onto the conductive layers 152B, 152G, 152R, and 152C. If a negative-type photosensitive material is used for the insulating film 127f, visible light or ultraviolet light is irradiated onto the region where the insulating layer 127 will be formed.

[0432] The exposed region of the insulating film 127f can control the width of the insulating layer 127 to be formed later. In this embodiment, the insulating layer 127 is processed so as to have a portion overlapping the upper surface of the conductive layer 151.

[0433] Here, by providing an oxygen barrier insulating layer (e.g., an aluminum oxide film) as one or both of the sacrificial layer 158 (the sacrificial layer 158B, the sacrificial layer 158G, and the sacrificial layer 158R) and the inorganic insulating film 125f, it is possible to reduce the diffusion of oxygen into the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R. When the organic compound layer is irradiated with light (visible light or ultraviolet light), the organic compound contained in the organic compound layer becomes excited, which may promote a reaction with oxygen contained in the atmosphere. More specifically, when light (visible light or ultraviolet light) is irradiated to the organic compound layer in an oxygen-containing atmosphere, oxygen may bond to the organic compound contained in the organic compound layer. By providing the sacrificial layer 158 and the inorganic insulating film 125f on the island-shaped organic compound layer, it is possible to reduce the bonding of oxygen in the atmosphere to the organic compound contained in the organic compound layer.

[0434] 9(A), development is performed to remove the exposed region of the insulating film 127f, thereby forming the insulating layer 127a. The insulating layer 127a is formed in a region sandwiched between any two of the conductive layers 152B, 152G, and 152R, and in a region surrounding the conductive layer 152C. When an acrylic resin is used for the insulating film 127f, an alkaline solution, such as TMAH, can be used as the developer.

[0435] 9(B), an etching process is performed using the insulating layer 127a as a mask to remove a portion of the inorganic insulating film 125f and reduce the thickness of a portion of the sacrificial layers 158B, 158G, and 158R. As a result, the inorganic insulating layer 125 is formed below the insulating layer 127a. Note that, hereinafter, the etching process for processing the inorganic insulating film 125f using the insulating layer 127a as a mask may be referred to as a first etching process.

[0436] That is, in the first etching process, the sacrificial layers 158B, 158G, and 158R are not completely removed, and the etching process is stopped when the film thicknesses of the sacrificial layers 158B, 158G, and 158R are reduced. In this way, by leaving the sacrificial layers 158B, 158G, and 158R on the organic compound layers 103B, 103G, and 103R, respectively, it is possible to prevent the organic compound layers 103B, 103G, and 103R from being damaged in subsequent processes.

[0437] The first etching process can be performed by dry etching or wet etching. Note that, when the inorganic insulating film 125f is formed using the same material as the sacrificial layers 158B, 158G, and 158R, the inorganic insulating film 125f and the exposed sacrificial layer 158 can be thinned in one go by the first etching process, which is preferable.

[0438] By performing etching using insulating layer 127a, which has tapered side surfaces, as a mask, the side surfaces of inorganic insulating layer 125 and the upper end portions of the side surfaces of sacrificial layers 158B, 158G, and 158R can be tapered relatively easily.

[0439] For example, when the first etching process is performed by dry etching, a chlorine-based gas can be used. Examples of chlorine-based gases that can be used include Cl2, BCl3, SiCl4, and CCl4, either singly or in combination. Furthermore, oxygen gas, hydrogen gas, helium gas, and argon gas can be added to the chlorine-based gas, either singly or in combination. By using dry etching, thin regions of the sacrificial layers 158B, 158G, and 158R can be formed with good in-plane uniformity.

[0440] Furthermore, for example, the first etching process can be performed by wet etching, which can reduce damage to the organic compound layers 103B, 103G, and 103R compared to when dry etching is used.

[0441] For wet etching, it is preferable to use an acidic chemical solution, such as a chemical solution containing one of phosphoric acid, hydrofluoric acid, nitric acid, acetic acid, oxalic acid, and sulfuric acid, or a mixed chemical solution of two or more acids (also called mixed acid).

[0442] Alternatively, wet etching can be performed using an alkaline solution. For example, an alkaline solution such as TMAH can be used to wet etch an aluminum oxide film. In this case, wet etching can be performed using a paddle method.

[0443] Next, heat treatment (also referred to as post-baking) is performed. By performing the heat treatment, the insulating layer 127a can be transformed into the insulating layer 127 having tapered side surfaces (FIG. 9C). The heat treatment is performed at a temperature lower than the upper temperature limit of the organic compound layer. The heat treatment can be performed at a substrate temperature of 50° C. to 200° C., preferably 60° C. to 150° C., more preferably 70° C. to 130° C. The heating atmosphere may be an air atmosphere or an inert atmosphere. The heating atmosphere may be an atmospheric pressure atmosphere or a reduced-pressure atmosphere. The substrate temperature in the heat treatment in this step is preferably higher than that in the heat treatment (pre-baking) after the formation of the insulating film 127f.

[0444] The heat treatment can improve the adhesion between the insulating layer 127 and the inorganic insulating layer 125, and also improve the corrosion resistance of the insulating layer 127. Furthermore, the insulating layer 127a is deformed, so that the end portion of the inorganic insulating layer 125 can be covered with the insulating layer 127.

[0445] By not completely removing the sacrificial layers 158B, 158G, and 158R in the first etching process and leaving the sacrificial layers 158B, 158G, and 158R in a thinner state, the organic compound layers 103B, 103G, and 103R can be prevented from being damaged and deteriorated in the heat treatment, thereby improving the reliability of the light-emitting device.

[0446] 10A, an etching process is performed using the insulating layer 127 as a mask to remove portions of the sacrificial layer 158B, the sacrificial layer 158G, and the sacrificial layer 158R. Note that at this time, a portion of the inorganic insulating layer 125 may also be removed. By this etching process, openings are formed in the sacrificial layer 158B, the sacrificial layer 158G, and the sacrificial layer 158R, and the top surfaces of the organic compound layer 103B, the organic compound layer 103G, the organic compound layer 103R, and the conductive layer 152C are exposed through the openings. Note that, hereinafter, the etching process that uses the insulating layer 127 as a mask to expose the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R may be referred to as a second etching process.

[0447] The second etching process is performed by wet etching. By using the wet etching method, damage to the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R can be reduced compared to when using the dry etching method. The wet etching can be performed using an acidic chemical solution or an alkaline solution, as in the first etching process.

[0448] Furthermore, after exposing portions of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R, a heat treatment may be further performed. This heat treatment can remove water contained in the organic compound layer and water adsorbed to the surface of the organic compound layer. This heat treatment may also change the shape of the insulating layer 127. Specifically, the insulating layer 127 may extend to cover at least one of the ends of the inorganic insulating layer 125, the ends of the sacrificial layer 158B, the sacrificial layer 158G, and the sacrificial layer 158R, and the top surfaces of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R.

[0449] Note that Figure 10(A) shows an example in which a portion of the end of the sacrificial layer 158G (specifically, the tapered portion formed by the first etching process) is covered with the insulating layer 127, and the tapered portion formed by the second etching process is exposed (see Figure 3(A)).

[0450] The insulating layer 127 may also cover the entire end of the sacrificial layer 158G. For example, the end of the insulating layer 127 may hang down and cover the end of the sacrificial layer 158G. For example, the end of the insulating layer 127 may contact the top surface of at least one of the organic compound layer 103B, the organic compound layer 103G, and the organic compound layer 103R.

[0451] 10(B), a common electrode 155 is formed on the organic compound layer 103B, the organic compound layer 103G, the organic compound layer 103R, 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. Alternatively, the common electrode 155 may be formed by stacking a film formed by evaporation and a film formed by sputtering.

[0452] 10(C), the cap layer 131 is formed on the common electrode 155. The cap layer 131 can be formed by a method such as vacuum deposition, sputtering, CVD, or ALD.

[0453] Subsequently, the substrate 120 is attached over the cap layer 131 using the resin layer 122, whereby a light-emitting device can be manufactured. As described above, in the method for manufacturing a light-emitting device of one embodiment of the present invention, the insulating layer 156 is provided so as to have a region overlapping with a 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. This can increase the yield of light-emitting devices and suppress the occurrence of defects.

[0454] As described above, in the manufacturing method of the light-emitting device according to one embodiment of the present invention, the island-shaped organic compound layers 103B, 103G, and 103R are formed by forming films over the entire surface and then processing them, rather than using a fine metal mask. This allows the island-shaped layers to be formed with uniform thicknesses. This allows a high-resolution light-emitting device or a light-emitting device with a high aperture ratio to be realized. Furthermore, even when the resolution or aperture ratio is high and the distance between subpixels is extremely short, the organic compound layers 103B, 103G, and 103R can be prevented from contacting each other in adjacent subpixels. Therefore, leakage current between subpixels can be suppressed. This prevents crosstalk and realizes a light-emitting device with extremely high contrast. Furthermore, a light-emitting device with excellent characteristics can be provided, even if the light-emitting device includes tandem light-emitting devices fabricated by photolithography.

[0455] The structure described in this embodiment mode can be used in appropriate combination with structures described in other embodiments.

[0456] (Fourth embodiment) In this embodiment, a light-emitting device of one embodiment of the present invention will be described with reference to FIGS. 11A to 11G and 12A to 12I.

[0457] [Pixel layout] In this embodiment, pixel layouts different from that shown in Fig. 2 will be mainly described. There are no particular limitations on the arrangement of sub-pixels, and various methods can be applied. Examples of sub-pixel arrangements include a stripe arrangement, an S-stripe arrangement, a matrix arrangement, a delta arrangement, a Bayer arrangement, and a pentile arrangement.

[0458] The top shape of the sub-pixels shown in the drawings in this embodiment mode corresponds to the top shape of the light-emitting region.

[0459] The top surface shape of the subpixel may be, for example, a triangle, a quadrangle (including a rectangle and a square), a polygon such as a pentagon, a polygon with rounded corners, an ellipse, or a circle.

[0460] Furthermore, the layout of the circuits constituting the sub-pixels is not limited to the range of the sub-pixels shown in the drawings, and may be arranged outside of the range.

[0461] An S-stripe arrangement is applied to the pixel 178 shown in Fig. 11(A). The pixel 178 shown in Fig. 11(A) is composed of three subpixels: a subpixel 110R, a subpixel 110G, and a subpixel 110B.

[0462] The pixel 178 shown in FIG. 11B includes a subpixel 110R having a generally trapezoidal or triangular top surface shape with rounded corners, a subpixel 110G having a generally trapezoidal or triangular top surface shape with rounded corners, and a subpixel 110B having a generally rectangular or hexagonal top surface shape with rounded corners. The subpixel 110R has a larger light-emitting area than the subpixel 110G. Thus, the shape and size of each subpixel can be determined independently. For example, the more reliable the light-emitting device, the smaller the size of the subpixel.

[0463] The Pentile arrangement is applied to the pixels 124a and 124b shown in Fig. 11(C). Fig. 11(C) shows an example in which the pixel 124a having the subpixel 110R and the subpixel 110G and the pixel 124b having the subpixel 110G and the subpixel 110B are arranged alternately.

[0464] 11(D) to 11(F) are arranged in a delta configuration. Pixel 124a has two subpixels (subpixel 110R and subpixel 110G) in the top row (first row) and one subpixel (subpixel 110B) in the bottom row (second row). Pixel 124b has one subpixel (subpixel 110B) in the top row (first row) and two subpixels (subpixel 110R and subpixel 110G) in the bottom row (second row).

[0465] Figure 11(D) is an example in which each sub-pixel has an approximately rectangular top surface shape with rounded corners, Figure 11(E) is an example in which each sub-pixel has a circular top surface shape, and Figure 11(F) is an example in which each sub-pixel has an approximately hexagonal top surface shape with rounded corners.

[0466] In Fig. 11(F), each subpixel is arranged inside a densely arranged hexagonal region. Each subpixel is arranged so that it is surrounded by six other subpixels when focusing on one subpixel. Furthermore, subpixels that emit light of the same color are arranged so that they are not adjacent to each other. For example, when focusing on subpixel 110R, three subpixels 110G and three subpixels 110B are arranged alternately to surround it.

[0467] 11G shows an example in which subpixels of each color are arranged in a zigzag pattern. Specifically, when viewed from above, the positions of the upper sides of two subpixels aligned in the row direction (for example, subpixels 110R and 110G, or subpixels 110G and 110B) are misaligned.

[0468] 11(A) to 11(G), it is preferable that the subpixel 110R is the subpixel R that emits red light, the subpixel 110G is the subpixel G that emits green light, and the subpixel 110B is the subpixel B that emits blue light. Note that the configuration of the subpixels is not limited to this, and the colors that the subpixels emit and their arrangement order can be determined appropriately. For example, the subpixel 110G may be the subpixel R that emits red light, and the subpixel 110R may be the subpixel G that emits green light.

[0469] In photolithography, the finer the pattern to be processed, the more significant the effect of light diffraction becomes. This impairs the fidelity of the photomask pattern when it is transferred by exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, a pattern with rounded corners is likely to be formed. As a result, the top surface shape of the subpixel may become a polygon with rounded corners, an ellipse, a circle, or the like.

[0470] Furthermore, in a method for manufacturing a light-emitting device according to one embodiment of the present invention, an organic compound layer is processed into an island shape using a resist mask. The resist film formed on the organic compound layer needs to be cured at a temperature lower than the heat resistance temperature of the organic compound layer. Therefore, depending on the heat resistance temperature of the material for the organic compound layer and the curing temperature of the resist material, the resist film may not be cured sufficiently. A resist film that is not cured sufficiently may have a shape that is different from the desired shape during processing. As a result, the top surface shape of the organic compound layer may be a polygon with rounded corners, an ellipse, a circle, or the like. For example, when a resist mask with a square top surface shape is formed, a resist mask with a circular top surface shape may be formed, resulting in a circular top surface shape of the organic compound layer.

[0471] In order to form the top surface of the organic compound layer into a desired shape, a technique for correcting the mask pattern in advance (OPC (Optical Proximity Correction) technique) may be used so that the design pattern and the transfer pattern coincide with each other. Specifically, in the OPC technique, a correction pattern is added to, for example, the corners of the figure on the mask pattern.

[0472] As shown in FIGS. 12A to 12I, a pixel can have four types of subpixels.

[0473] The pixels 178 shown in FIGS. 12(A) to 12(C) are arranged in a stripe pattern.

[0474] Figure 12(A) is an example in which each subpixel has a rectangular top surface shape, Figure 12(B) is an example in which each subpixel has a top surface shape that is a combination of two semicircles and a rectangle, and Figure 12(C) is an example in which each subpixel has an elliptical top surface shape.

[0475] The pixels 178 shown in FIGS. 12(D) to 12(F) are arranged in a matrix.

[0476] Figure 12(D) is an example in which each sub-pixel has a square top surface shape, Figure 12(E) is an example in which each sub-pixel has an approximately square top surface shape with rounded corners, and Figure 12(F) is an example in which each sub-pixel has a circular top surface shape.

[0477] 12(G) and 12(H) show an example in which one pixel 178 is configured in two rows and three columns.

[0478] 12(G) has three subpixels (subpixel 110R, subpixel 110G, and subpixel 110B) in the top row (first row) and one subpixel (subpixel 110W) in the bottom row (second row). In other words, pixel 178 has subpixel 110R in the left column (first column), subpixel 110G in the center column (second column), subpixel 110B in the right column (third column), and subpixel 110W across these three columns.

[0479] The pixel 178 shown in FIG. 12(H) has three subpixels (subpixel 110R, subpixel 110G, and subpixel 110B) in the top row (first row) and three subpixels 110W in the bottom row (second row). In other words, the pixel 178 has subpixel 110R and subpixel 110W in the left column (first column), subpixel 110G and subpixel 110W in the center column (second column), and subpixel 110B and subpixel 110W in the right column (third column). By aligning the subpixels in the top row and bottom row as shown in FIG. 12(H), it becomes possible to efficiently remove dust that may occur during the manufacturing process, for example. Therefore, a light-emitting device with high display quality can be provided.

[0480] In the pixel 178 shown in FIGS. 12(G) and 12(H), the subpixels 110R, 110G, and 110B are laid out in a stripe arrangement, which can improve the display quality.

[0481] FIG. 12(I) shows an example in which one pixel 178 is configured in three rows and two columns.

[0482] 12(I) has subpixel 110R in the top row (first row), subpixel 110G in the middle row (second row), subpixel 110B across the first and second rows, and one subpixel (subpixel 110W) in the bottom row (third row). In other words, pixel 178 has subpixel 110R and subpixel 110G in the left column (first column), subpixel 110B in the right column (second column), and subpixel 110W across these two columns.

[0483] In the pixel 178 shown in FIG. 12(I), the layout of the subpixels 110R, 110G, and 110B is a so-called S-stripe arrangement, which can improve the display quality.

[0484] 12A to 12I includes four subpixels: subpixel 110R, subpixel 110G, subpixel 110B, and subpixel 110W. For example, the subpixel 110R may be a subpixel that emits red light, the subpixel 110G may be a subpixel that emits green light, the subpixel 110B may be a subpixel that emits blue light, and the subpixel 110W may be a subpixel that emits white light. Note that at least one of the subpixels 110R, 110G, 110B, and 110W may be a subpixel that emits cyan light, a subpixel that emits magenta light, a subpixel that emits yellow light, or a subpixel that emits near-infrared light.

[0485] As described above, in the light-emitting device of one embodiment of the present invention, various layouts can be applied to pixels each including a subpixel having a light-emitting device.

[0486] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when multiple configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0487] (Embodiment 5) In this embodiment, a light-emitting device according to one embodiment of the present invention will be described.

[0488] The light emitting device of the present embodiment can be a high-definition light emitting device, and therefore can be used for the display unit of a wristwatch-type or bracelet-type information terminal (wearable device), a head-mounted display (HMD) or other VR device, and a head-mounted wearable device such as a glasses-type AR device.

[0489] The light-emitting device of this embodiment can be a high-resolution light-emitting device or a large-sized light-emitting device. Therefore, the light-emitting device of this embodiment can be used in the display portion of electronic devices having relatively large screens, such as television sets, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound reproducing devices.

[0490] [Display module] 13A shows a perspective view of a display module 280. The display module 280 includes a light-emitting device 100A and an FPC 290. Note that the light-emitting device included in the display module 280 is not limited to the light-emitting device 100A, and may be either a light-emitting device 100B or a light-emitting device 100C, which will be described later.

[0491] The display module 280 has a substrate 291 and a substrate 292. The display module 280 has a display unit 281. The display unit 281 is a region that displays an image in the display module 280, and is a region where light from each pixel provided in a pixel unit 284 (described later) can be viewed.

[0492] 13(B) is a perspective view schematically showing the configuration on the substrate 291 side. A circuit portion 282, a pixel circuit portion 283 on the circuit portion 282, and a pixel portion 284 on the pixel circuit portion 283 are stacked on the substrate 291. A terminal portion 285 for connecting to an FPC 290 is provided in a portion of the substrate 291 that does not overlap with the pixel portion 284. The terminal portion 285 and the circuit portion 282 are electrically connected by a wiring portion 286 composed of a plurality of wirings.

[0493] The pixel section 284 has a plurality of periodically arranged pixels 284a. An enlarged view of one pixel 284a is shown on the right side of Fig. 13(B). The various configurations described in the previous embodiments can be applied to the pixel 284a.

[0494] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0495] One pixel circuit 283a is a circuit that controls the driving of multiple elements included in one pixel 284a. One pixel circuit 283a can be configured to have three circuits that control the light emission of one light-emitting device. For example, the pixel circuit 283a can be configured to have at least one selection transistor, one current control transistor (drive transistor), and a capacitor for each light-emitting device. In this case, a gate signal is input to the gate of the selection transistor, and a video signal is input to the source or drain. This realizes an active matrix light-emitting device.

[0496] The circuit portion 282 includes a circuit for driving each pixel circuit 283a of the pixel circuit portion 283. For example, it is preferable that the circuit portion 282 includes one or both of a gate line driver circuit and a source line driver circuit. In addition, the circuit portion 282 may include at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0497] The FPC 290 functions as wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit section 282. An IC may be mounted on the FPC 290.

[0498] The display module 280 can be configured such that one or both of the pixel circuit unit 283 and the circuit unit 282 are stacked below the pixel unit 284, thereby enabling the aperture ratio (effective display area ratio) of the display unit 281 to be extremely high. For example, the aperture ratio of the display unit 281 can be set to 40% or more and less than 100%, preferably 50% or more and 95% or less, and more preferably 60% or more and 95% or less. Furthermore, the pixels 284a can be arranged at an extremely high density, enabling the resolution of the display unit 281 to be extremely high. For example, it is preferable that the pixels 284a are arranged in the display unit 281 at a resolution of 2000 ppi or more, preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 6000 ppi or more, and 20000 ppi or less, or 30000 ppi or less.

[0499] Such a display module 280 has extremely high resolution and can therefore be suitably used in VR devices such as HMDs or eyeglass-type AR devices. For example, even in a configuration in which the display unit of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display unit 281, so that even when the display unit is enlarged with lenses, the pixels are not visible, allowing for a highly immersive display. Furthermore, the display module 280 is not limited to this, and can be suitably used in electronic devices having relatively small display units. For example, it can be suitably used in the display unit of a wearable electronic device such as a wristwatch.

[0500] [Light-emitting device 100A] The light emitting device 100A shown in FIG. 14A 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.

[0501] The substrate 301 corresponds to the substrate 291 in FIGS. 13A and 13B. The transistor 310 is a transistor having a channel formation region in the substrate 301. The substrate 301 can be, for example, a semiconductor substrate such as a single crystal silicon substrate. The transistor 310 includes a part of the substrate 301, a conductive layer 311, a low-resistance region 312, an insulating layer 313, and an insulating layer 314. The conductive layer 311 functions as a gate electrode. The insulating layer 313 is located between the substrate 301 and the conductive layer 311 and functions as a gate insulating layer. The low-resistance region 312 is a region in which the substrate 301 is doped with impurities and functions as a source or drain. The insulating layer 314 is provided to cover a side surface of the conductive layer 311.

[0502] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301 .

[0503] In addition, an insulating layer 261 is provided to cover the transistor 310 , and a capacitor 240 is provided on the insulating layer 261 .

[0504] Capacitor 240 has conductive layer 241, conductive layer 245, and insulating layer 243 located therebetween. Conductive layer 241 functions as one electrode of capacitor 240, conductive layer 245 functions as the other electrode of capacitor 240, and insulating layer 243 functions as a dielectric of capacitor 240.

[0505] The conductive layer 241 is provided over the insulating layer 261 and is buried in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source and drain of the transistor 310 by a plug 271 buried in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping with the conductive layer 241 with the insulating layer 243 interposed therebetween.

[0506] An insulating layer 255 is provided covering the capacitor 240, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. The light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B are provided on the insulating layer 175. FIG. 14A shows an example in which the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B have the layered structure shown in FIG. 6A. An insulator is provided in the region between adjacent light-emitting devices. For example, in FIG. 14A, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided in this region.

[0507] Insulating layer 156R is provided to have a region overlapping with a side surface of conductive layer 151R of light-emitting device 130R, insulating layer 156G is provided to have a region overlapping with a side surface of conductive layer 151G of light-emitting device 130G, and insulating layer 156B is provided to have a region overlapping with a side surface of conductive layer 151B of light-emitting device 130B. Furthermore, conductive layer 152R is provided to cover conductive layer 151R and insulating layer 156R, conductive layer 152G is provided to cover conductive layer 151G and insulating layer 156G, and conductive layer 152B is provided to cover conductive layer 151B and insulating layer 156B. Furthermore, a sacrificial layer 158R is located on the organic compound layer 103R of the light-emitting device 130R, a sacrificial layer 158G is located on the organic compound layer 103G of the light-emitting device 130G, and a sacrificial layer 158B is located on the organic compound layer 103B of the light-emitting device 130B.

[0508] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source or drain of the transistor 310 via an insulating layer 243, an insulating layer 255, an insulating layer 174, a plug 256 embedded in the insulating layer 175, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. The height of the top surface of the insulating layer 175 and the height of the top surface of the plug 256 are the same or approximately the same. Various conductive materials can be used for the plug.

[0509] Furthermore, a substrate 120 is bonded onto the cap layer 131 of each light-emitting device by a resin layer 122. For details of the components from the light-emitting device 130 to the substrate 120, refer to Embodiment 2. The substrate 120 corresponds to the substrate 292 in FIG. 13(A).

[0510] Fig. 14(B) is a modified example of the light-emitting device 100A shown in Fig. 14(A). The light-emitting device shown in Fig. 14(B) has a colored layer 132R, a colored layer 132G, and a colored layer 132B, and the light-emitting device 130 has an area that overlaps with one of the colored layers 132R, 132G, and 132B. In the light-emitting device shown in Fig. 14(B), the light-emitting device 130 can emit, for example, white light. Furthermore, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light.

[0511] [Light-emitting device 100B] FIG. 15 shows a perspective view of the light emitting device 100B, and FIG. 16(A) shows a cross-sectional view of the light emitting device 100B.

[0512] Light emitting device 100B has a configuration in which substrate 352 and substrate 351 are bonded together. In Fig. 15, substrate 352 is clearly indicated by a dashed line.

[0513] The light emitting device 100B has a pixel portion 177, a connection portion 140, a circuit 356, wiring 355, etc. Fig. 15 shows an example in which an IC 354 and an FPC 353 are mounted on the light emitting device 100B. Therefore, the configuration shown in Fig. 15 can also be called a display module having the light emitting device 100B, an IC (integrated circuit), and an FPC. Here, a light emitting device having a connector such as an FPC attached to a substrate, or a light emitting device having an IC mounted on the substrate, is called a display module.

[0514] The connection section 140 is provided outside the pixel section 177. The connection section 140 can be provided along one side or multiple sides of the pixel section 177. There may be one or multiple connection sections 140. FIG. 15 shows an example in which the connection sections 140 are provided so as to surround the four sides of the display section. The connection section 140 electrically connects the common electrode of the light-emitting device and the conductive layer, and can supply a potential to the common electrode.

[0515] The circuit 356 can be, for example, a scanning line driver circuit.

[0516] 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 from the IC 354.

[0517] 15 shows an example in which an IC 354 is provided on a substrate 351 by a COG (Chip On Glass) method or a COF (Chip on Film) method. The IC 354 may be, for example, an IC having a scanning line driver circuit or a signal line driver circuit. Note that the light-emitting device 100B and the display module may not necessarily include an IC. Alternatively, the IC may be mounted on an FPC by, for example, a COF method.

[0518] Figure 16(A) shows an example of a cross section of the light-emitting device 100B, where a portion of the region including the FPC 353, a portion of the circuit 356, a portion of the pixel portion 177, a portion of the connection portion 140, and a portion of the region including the end portion are cut.

[0519] The light-emitting device 100B shown in Figure 16(A) has, between a substrate 351 and a substrate 352, 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.

[0520] The light-emitting devices 130R, 130G, and 130B each have the layered structure shown in Fig. 6A, except for the configuration of the pixel electrodes. For details of the light-emitting devices, see Embodiments 1 and 2.

[0521] Light-emitting device 130R includes conductive layer 224R, conductive layer 151R on conductive layer 224R, and conductive layer 152R on conductive layer 151R. Light-emitting device 130G includes conductive layer 224G, conductive layer 151G on conductive layer 224G, and conductive layer 152G on conductive layer 151G. Light-emitting device 130B includes conductive layer 224B, conductive layer 151B on conductive layer 224B, and conductive layer 152B on conductive layer 151B. Here, conductive layer 224R, conductive layer 151R, and conductive layer 152R may collectively be referred to as the pixel electrode of light-emitting device 130R, and conductive layer 151R and conductive layer 152R excluding conductive layer 224R may also be referred to as the pixel electrode of light-emitting device 130R.

[0522] Similarly, conductive layer 224G, conductive layer 151G, and conductive layer 152G may be collectively referred to as the pixel electrode of light-emitting device 130G, and conductive layer 151G and conductive layer 152G excluding conductive layer 224G may be collectively referred to as the pixel electrode of light-emitting device 130G. Furthermore, conductive layer 224B, conductive layer 151B, and conductive layer 152B may be collectively referred to as the pixel electrode of light-emitting device 130B, and conductive layer 151B and conductive layer 152B excluding conductive layer 224B may be collectively referred to as the pixel electrode of light-emitting device 130B.

[0523] The conductive layer 224R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. An end of the conductive layer 151R is located outside an end of the conductive layer 224R. An insulating layer 156R is provided to have a region in contact with a side surface of the conductive layer 151R, and a conductive layer 152R is provided to cover the conductive layer 151R and the insulating layer 156R.

[0524] Conductive layer 224G, conductive layer 151G, conductive layer 152G, and insulating layer 156G in light-emitting device 130G, and conductive layer 224B, conductive layer 151B, conductive layer 152B, and insulating layer 156B in light-emitting device 130B are similar to conductive layer 224R, conductive layer 151R, conductive layer 152R, and insulating layer 156R in light-emitting device 130R, and therefore detailed description thereof will be omitted.

[0525] Recesses are formed in the conductive layers 224R, 224G, and 224B so as to cover the openings provided in the insulating layer 214. A layer 128 is buried in the recesses.

[0526] Layer 128 has the function of planarizing the recesses of conductive layer 224R, conductive layer 224G, and conductive layer 224B. Conductive layers 151R, 151G, and 151B, which are electrically connected to conductive layer 224R, conductive layer 224G, and conductive layer 224B, are provided on conductive layer 224R, conductive layer 224G, and conductive layer 224B and layer 128. Therefore, the regions overlapping with the recesses of conductive layer 224R, conductive layer 224G, and conductive layer 224B can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixel.

[0527] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be used for the layer 128 as appropriate. In particular, the layer 128 is preferably formed using an insulating material, and is particularly preferably formed using an organic insulating material. For example, the organic insulating materials that can be used for the insulating layer 127 described above can be used for the layer 128.

[0528] A cap layer 131 is provided on the common electrode 155. The cap layer 131 and the substrate 352 are bonded together via an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. A solid sealing structure, a hollow sealing structure, or the like can be applied to seal the light-emitting device 130. In FIG. 16(A), the space between the substrates 352 and 351 is filled with the adhesive layer 142, and a solid sealing structure is applied. Alternatively, the space may be filled with an inert gas (nitrogen, argon, etc.), and a hollow sealing structure may be applied. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting device. Alternatively, the space may be filled with a resin different from the frame-shaped adhesive layer 142.

[0529] An inorganic insulating film such as a nitrogen-containing film (e.g., a silicon nitride film) is provided as a solid sealing structure. It is preferable that the cap layer 131 and the inorganic insulating film are in contact with each other. The thickness of the inorganic insulating film is preferably larger than that of the cap layer, and the ordinary refractive index no of the inorganic insulating film is preferably larger than that of the cap layer no. This configuration is expected to have the effect of increasing the light extraction efficiency.

[0530] 16A shows an example in which the connection portion 140 has a conductive layer 224C obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive layer 151C obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive layer 152C obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. Also shown in FIG. 16A is an example in which an insulating layer 156C is provided so as to have a region overlapping with a side surface of the conductive layer 151C.

[0531] The light emitting device 100B is a top-emission type. Light emitted by the light emitting device is emitted toward the substrate 352. The substrate 352 is preferably made of a material that is highly transparent to visible light. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0532] The transistor 201 and the transistor 205 are both formed over a substrate 351. These transistors can be manufactured using the same material and the same process.

[0533] An insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided over the substrate 351 in this order. A part of the insulating layer 211 functions as a gate insulating layer for each transistor. A part of the insulating layer 213 functions as a gate insulating layer for each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and functions as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistors are not limited, and each may be a single layer or two or more layers.

[0534] It is preferable that at least one insulating layer covering the transistor is made of a material that is resistant to the diffusion of impurities such as water and hydrogen. This allows the insulating layer to function as a barrier layer. With this structure, it is possible to effectively prevent impurities from diffusing into the transistor from the outside, thereby improving the reliability of the light-emitting device.

[0535] It is preferable to use an inorganic insulating film for each of the insulating layers 211, 213, and 215. Examples of the inorganic insulating film that can be used include a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, an aluminum oxide film, and an aluminum nitride film. Alternatively, a hafnium oxide film, an yttrium oxide film, a zirconium oxide film, a gallium oxide film, a tantalum oxide film, a magnesium oxide film, a lanthanum oxide film, a cerium oxide film, and a neodymium oxide film may also be used. Two or more of the above insulating films may be stacked.

[0536] An organic insulating layer is suitable for the insulating layer 214, which functions as a planarizing layer. Materials that can be used for the organic insulating layer include acrylic resin, polyimide resin, epoxy resin, polyamide resin, polyimideamide resin, siloxane resin, benzocyclobutene-based resin, phenolic resin, and precursors of these resins. Alternatively, the insulating layer 214 may have a laminated structure of an organic insulating layer and an inorganic insulating layer. The outermost layer of the insulating layer 214 preferably functions as an etching protection layer. This prevents recesses from being formed in the insulating layer 214 during processing of the conductive layer 224R, the conductive layer 151R, the conductive layer 152R, or the like. Alternatively, recesses may be formed in the insulating layer 214 during processing of the conductive layer 224R, the conductive layer 151R, the conductive layer 152R, or the like.

[0537] The transistor 201 and the transistor 205 each include a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source and a drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate. Here, the same hatching pattern is applied to multiple layers obtained by processing the same conductive film. The insulating layer 211 is located between the conductive layer 221 and the semiconductor layer 231. The insulating layer 213 is located between the conductive layer 223 and the semiconductor layer 231.

[0538] The structure of the transistor included in the light-emitting device of this embodiment is not particularly limited. For example, a planar transistor, a staggered transistor, an inverted staggered transistor, or the like can be used. Furthermore, either a top-gate transistor or a bottom-gate transistor structure may be used. Alternatively, gates may be provided above and below a semiconductor layer in which a channel is formed.

[0539] The transistor 201 and the transistor 205 have a structure in which a semiconductor layer in which a channel is formed is sandwiched between two gates. The two gates may be connected and the same signal may be supplied to drive the transistor. Alternatively, the threshold voltage of the transistor may be controlled by applying a potential for controlling the threshold voltage to one of the two gates and a potential for driving to the other.

[0540] The crystallinity of a semiconductor material used for a transistor is not particularly limited, and any of an amorphous semiconductor and a crystalline semiconductor (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor having a crystalline region in part) may be used. The use of a crystalline semiconductor is preferable because it can suppress deterioration of transistor characteristics.

[0541] A semiconductor layer of the transistor preferably contains a metal oxide. That is, the light-emitting device of this embodiment preferably uses a transistor using a metal oxide in a channel formation region (hereinafter referred to as an OS transistor).

[0542] Examples of crystalline oxide semiconductors include c-axis-aligned crystalline (CAAC)-OS and nanocrystalline (nc)-OS.

[0543] Alternatively, a transistor using silicon in a channel formation region (Si transistor) may be used. Examples of silicon include single crystal silicon, polycrystalline silicon, and amorphous silicon. In particular, a transistor having low temperature polysilicon (LTPS) in a semiconductor layer (hereinafter also referred to as an LTPS transistor) may be used. LTPS transistors have high field-effect mobility and good frequency characteristics.

[0544] By using Si transistors such as LTPS transistors, circuits that need to be driven at high frequencies (such as source driver circuits) can be built on the same substrate as the display unit, which simplifies the external circuits mounted on the light-emitting device and reduces component and mounting costs.

[0545] OS transistors have significantly higher field-effect mobility than transistors using amorphous silicon. Furthermore, OS transistors have significantly smaller source-drain leakage current in an off state (hereinafter also referred to as off-state current), and can retain charge accumulated in a capacitor connected in series with the transistor for a long period of time. Furthermore, the use of OS transistors can reduce the power consumption of light-emitting devices.

[0546] Furthermore, to increase the emission luminance of a light-emitting device included in a pixel circuit, it is necessary to increase the amount of current flowing through the light-emitting device. To achieve this, it is necessary to increase the source-drain voltage of the drive transistor included in the pixel circuit. Because OS transistors have a higher source-drain breakdown voltage than Si transistors, a high voltage can be applied between the source and drain of an OS transistor. Therefore, by using an OS transistor as the drive transistor included in a pixel circuit, it is possible to increase the amount of current flowing through the light-emitting device and increase the emission luminance of the light-emitting device.

[0547] Furthermore, when the transistor operates in the saturation region, OS transistors can reduce the change in source-drain current relative to a change in gate-source voltage compared to Si transistors. Therefore, by using OS transistors as the drive transistors in pixel circuits, the current flowing between the source and drain can be precisely controlled by changing the gate-source voltage, thereby controlling the amount of current flowing to the light-emitting device. This allows for a wider range of gradations in the pixel circuit.

[0548] Furthermore, in terms of the saturation characteristics of the current that flows when the transistor operates in the saturation region, OS transistors can pass a more stable current (saturation current) than Si transistors, even when the source-drain voltage gradually increases. Therefore, by using an OS transistor as a drive transistor, a stable current can be passed through a light-emitting device, even when the current-voltage characteristics of the light-emitting device vary. In other words, when operating in the saturation region, the source-drain current of an OS transistor remains almost unchanged even when the source-drain voltage increases, thereby stabilizing the light-emitting brightness of the light-emitting device.

[0549] As described above, by using an OS transistor as a driving transistor included in a pixel circuit, it is possible to achieve "suppression of black floating," "increase in light emission brightness," "multiple gradations," and "suppression of variations in light-emitting devices."

[0550] The semiconductor layer preferably contains, for example, indium, an element M1 (the element M1 is one or more elements selected from gallium, aluminum, silicon, boron, yttrium, tin, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, and magnesium), and zinc. In particular, the element M1 is preferably one or more elements selected from aluminum, gallium, yttrium, and tin.

[0551] In particular, it is preferable to use an oxide containing indium (In), gallium (Ga), and zinc (Zn) (also referred to as IGZO) for the semiconductor layer. Alternatively, it is preferable to use an oxide containing indium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium, gallium, tin, and zinc. Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), and zinc (Zn) (also referred to as IAZO). Alternatively, it is preferable to use an oxide containing indium (In), aluminum (Al), gallium (Ga), and zinc (Zn) (also referred to as IAGZO).

[0552] When the semiconductor layer is an In-M-Zn oxide, the atomic ratio of In in the In-M-Zn oxide is preferably equal to or greater than the atomic ratio of M. Examples of atomic ratios of metal elements in such In-M-Zn oxides include In:M:Zn=1:1:1 or a composition thereabout, In:M:Zn=1:1:1.2 or a composition thereabout, In:M:Zn=2:1:3 or a composition thereabout, In:M:Zn=3:1:2 or a composition thereabout, In:M:Zn=4:2:3 or a composition thereabout, In:M:Zn=4:2:4.1 or a composition thereabout, In:M:Zn=5:1:3 or a composition thereabout, In:M:Zn=5:1:6 or a composition thereabout, In:M:Zn=5:1:7 or a composition thereabout, In:M:Zn=5:1:8 or a composition thereabout, In:M:Zn=6:1:6 or a composition thereabout, and In:M:Zn=5:2:5 or a composition thereabout. The term "nearby composition" includes a range of ±30% of the desired atomic ratio.

[0553] For example, when describing a composition with an atomic ratio of In:Ga:Zn=4:2:3 or thereabout, this includes a case where, when the atomic ratio of In is 4, the atomic ratio of Ga is 1 or more and 3 or less, and the atomic ratio of Zn is 2 or more and 4 or less. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=5:1:6 or thereabout, this includes a case where, when the atomic ratio of In is 5, the atomic ratio of Ga is more than 0.1 and 2 or less, and the atomic ratio of Zn is 5 or more and 7 or less. Furthermore, when describing a composition with an atomic ratio of In:Ga:Zn=1:1:1 or thereabout, this includes a case where, when the atomic ratio of In is 1, the atomic ratio of Ga is more than 0.1 and 2 or less, and the atomic ratio of Zn is more than 0.1 and 2 or less.

[0554] The transistors included in the circuit 356 and the transistors included in the pixel portion 177 may have the same structure or different structures. The transistors included in the circuit 356 may all have the same structure or may have two or more types. Similarly, the transistors included in the pixel portion 177 may all have the same structure or may have two or more types.

[0555] All the transistors included in the pixel portion 177 may be OS transistors, all the transistors included in the pixel portion 177 may be Si transistors, or some of the transistors included in the pixel portion 177 may be OS transistors and the rest may be Si transistors.

[0556] For example, by using both an LTPS transistor and an OS transistor in the pixel portion 177, a light-emitting device with low power consumption and high driving capability can be realized. A configuration in which an LTPS transistor and an OS transistor are combined is sometimes called LTPO. It is preferable to use an OS transistor as a transistor that functions as a switch for controlling the conduction / non-conduction of wiring, and an LTPS transistor as a transistor for controlling current.

[0557] For example, one of the transistors included in the pixel portion 177 functions as a transistor for controlling the current flowing through the light-emitting device and can be called a driving transistor. One of the source and drain of the driving transistor is electrically connected to the pixel electrode of the light-emitting device. It is preferable to use an LTPS transistor as the driving transistor. This allows the current flowing through the light-emitting device in the pixel circuit to be increased.

[0558] On the other hand, another transistor in the pixel portion 177 functions as a switch for controlling pixel selection / deselection and can also be called a selection transistor. The gate of the selection transistor is electrically connected to a gate line, and one of the source and drain is electrically connected to a source line (signal line). It is preferable to use an OS transistor as the selection transistor. This allows the gradation of the pixel to be maintained even when the frame frequency is significantly reduced (for example, 1 fps or less), so power consumption can be reduced by stopping the driver when displaying a still image.

[0559] As described above, the light-emitting device of one embodiment of the present invention can have a high aperture ratio, high definition, high display quality, and low power consumption.

[0560] Note that a light-emitting device according to one embodiment of the present invention includes an OS transistor and a light-emitting device with an MML (metal maskless) structure. This structure can significantly reduce leakage current that may flow through the transistor and leakage current that may flow between adjacent light-emitting devices (also referred to as lateral leakage current). Furthermore, with this structure, when an image is displayed on the light-emitting device, a viewer can observe one or more of image clarity, image sharpness, high saturation, and a high contrast ratio. Note that a structure in which leakage current that may flow through the transistor and lateral leakage current between light-emitting devices are extremely low can minimize light leakage during black display (so-called floating black).

[0561] In particular, among light-emitting devices with an MML structure, by applying the SBS (Side By Side) structure described above, the layers provided between light-emitting devices (for example, organic layers shared between light-emitting devices, also called common layers) are configured to be separated, thereby eliminating or greatly reducing leakage current.

[0562] 16B and 16C show other structural examples of the transistor.

[0563] The transistor 209 and the transistor 210 each include a conductive layer 221 functioning as a gate, an insulating layer 211 functioning as a gate insulating layer, a semiconductor layer 231 including a channel formation region 231i and a pair of low-resistance regions 231n, a conductive layer 222a connected to one of the pair of low-resistance regions 231n, a conductive layer 222b connected to the other of the pair of low-resistance regions 231n, an insulating layer 225 functioning as a gate insulating layer, a conductive layer 223 functioning as a gate, and an insulating layer 215 covering the conductive layer 223. The insulating layer 211 is located between the conductive layer 221 and the channel formation region 231i. The insulating layer 225 is located at least between the conductive layer 223 and the channel formation region 231i. An insulating layer 218 covering the transistor may also be provided.

[0564] 16B shows an example in which the insulating layer 225 covers the top surface and side surfaces of the semiconductor layer 231. The conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings provided in the insulating layer 225 and the insulating layer 215, respectively. One of the conductive layer 222a and the conductive layer 222b functions as a source, and the other functions as a drain.

[0565] 16C, the insulating layer 225 overlaps with the channel formation region 231i of the semiconductor layer 231 but does not overlap with the low-resistance region 231n. For example, the insulating layer 225 is processed using the conductive layer 223 as a mask, thereby manufacturing the structure shown in FIG. 16C. In FIG. 16C, the insulating layer 215 is provided to cover the insulating layer 225 and the conductive layer 223, and the conductive layer 222a and the conductive layer 222b are connected to the low-resistance region 231n through openings in the insulating layer 215.

[0566] A connection portion 204 is provided in a region of the substrate 351 where the substrate 352 does not overlap. In the connection portion 204, a wiring 355 is electrically connected to the FPC 353 via a conductive layer 166 and a connection layer 242. The conductive layer 166 has an example of a laminated structure including a conductive film obtained by processing the same conductive film as the conductive layers 224R, 224G, and 224B, a conductive film obtained by processing the same conductive film as the conductive layers 151R, 151G, and 151B, and a conductive film obtained by processing the same conductive film as the conductive layers 152R, 152G, and 152B. The conductive layer 166 is exposed on the upper surface of the connection portion 204. This allows the connection portion 204 and the FPC 353 to be electrically connected via the connection layer 242.

[0567] It is preferable to provide a light-shielding layer 157 on the surface of the substrate 352 facing the substrate 351. The light-shielding layer 157 can be provided between adjacent light-emitting devices, on the connection section 140, on the circuit 356, etc. Also, various optical members can be arranged on the outside of the substrate 352.

[0568] The substrate 351 and the substrate 352 can be made of the same material as can be used for the substrate 120 .

[0569] The adhesive layer 142 can be made of a material that can be used for the resin layer 122 .

[0570] The connection layer 242 may be an anisotropic conductive film (ACF), an anisotropic conductive paste (ACP), or the like.

[0571] [Light Emitting Device 100H] The light emitting device 100H shown in FIG. 17 differs from the light emitting device 100B shown in FIG. 16(A) mainly in that it is a bottom emission type light emitting device.

[0572] Light emitted from the light emitting device is emitted toward the substrate 351. It is preferable that a material with high transparency to visible light is used for the substrate 351. On the other hand, the light transparency of the material used for the substrate 352 is not an issue.

[0573] A light-shielding layer 157 is preferably formed between the substrate 351 and the transistor 201 and between the substrate 351 and the transistor 205. Figure 17 shows an example in which the light-shielding layer 157 is provided over the substrate 351, the insulating layer 153 is provided over the light-shielding layer 157, and the transistors 201, 205, etc. are provided over the insulating layer 153.

[0574] Light emitting device 130R includes conductive layer 112R, conductive layer 126R on conductive layer 112R, and conductive layer 129R on conductive layer 126R.

[0575] Light emitting device 130B includes conductive layer 112B, conductive layer 126B on conductive layer 112B, and conductive layer 129B on conductive layer 126B.

[0576] The conductive layers 112R, 112B, 126R, 126B, 129R, and 129B are made of a material that is highly transparent to visible light. The common electrode 155 is preferably made of a material that reflects visible light.

[0577] Although the light emitting device 130G is not shown in FIG. 17, the light emitting device 100H is also provided with the light emitting device 130G.

[0578] In addition, although FIG. 17 and other figures show an example in which the top surface of the layer 128 has a flat portion, the shape of the layer 128 is not particularly limited.

[0579] [Light-emitting device 100C] The light emitting device 100C shown in FIG. 18(A) is a modification of the light emitting device 100B shown in FIG. 16(A), and differs from the light emitting device 100B mainly in that it has colored layers 132R, 132G, and 132B.

[0580] In the light emitting device 100C, the light emitting device 130 has an area overlapping one of the colored layer 132R, the colored layer 132G, and the colored layer 132B. The colored layer 132R, the colored layer 132G, and the colored layer 132B can be provided on the surface of the substrate 352 facing the substrate 351. An end of the colored layer 132R, an end of the colored layer 132G, and an end of the colored layer 132B can overlap the light-shielding layer 157.

[0581] In the light emitting device 100C, the light emitting device 130 can emit, for example, white light. Furthermore, for example, the colored layer 132R can transmit red light, the colored layer 132G can transmit green light, and the colored layer 132B can transmit blue light. The light emitting device 100C may be configured such that the colored layers 132R, 132G, and 132B are provided between the cap layer 131 and the adhesive layer 142.

[0582] 16A, 18A, and the like show examples in which the top surface of the layer 128 has a flat portion, but there is no particular limitation on the shape of the layer 128. Modified examples of the layer 128 are shown in FIGS.

[0583] As shown in FIGS. 18(B) and 18(D), the upper surface of the layer 128 can be configured to have a shape with a recess in the center and its vicinity in cross section, that is, a shape with a concave curved surface.

[0584] As shown in FIG. 18(C), the upper surface of the layer 128 can be configured so that the center and its vicinity bulge in cross section, that is, have a convex curved shape.

[0585] The upper surface of layer 128 may have one or both of a convex curved surface and a concave curved surface. The number of convex curved surfaces and concave curved surfaces that the upper surface of layer 128 has is not limited, and may be one or more.

[0586] Furthermore, the height of the upper surface of layer 128 and the height of the upper surface of conductive layer 224R may be the same or approximately the same, or may be different from each other. For example, the height of the upper surface of layer 128 may be lower or higher than the height of the upper surface of conductive layer 224R.

[0587] 18(B) can also be considered an example in which layer 128 is contained within a recess formed in conductive layer 224R. On the other hand, as shown in FIG. 18(D), layer 128 may be present outside the recess formed in conductive layer 224R, that is, the width of the upper surface of layer 128 may be wider than the recess.

[0588] This embodiment mode can be combined with other embodiment modes or examples as appropriate. In addition, in this specification, when multiple configuration examples are shown in one embodiment mode, the configuration examples can be combined as appropriate.

[0589] (Embodiment 6) In this embodiment, an electronic device according to one embodiment of the present invention will be described.

[0590] The electronic devices of this embodiment include the light-emitting device of one embodiment of the present invention in their display portions. The light-emitting device of one embodiment of the present invention is highly reliable and can easily achieve high definition and high resolution. Therefore, the light-emitting device can be used in the display portions of various electronic devices.

[0591] Examples of electronic devices include electronic devices with relatively large screens such as television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game machines, personal digital assistants, and sound playback devices.

[0592] In particular, ...

Claims

1. An organic compound represented by general formula (G1): 【Chemistry 1】 (In the formula, R １ ~R ４ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituent represented by the following general formula (G1-1): ５ ~R ８ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituent represented by the following general formula (G1-3): ５ ~R ８ At least one of the groups represented by the following general formula (G1-3) is a substituent, １１ represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar １２ represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; n11 represents an integer of 0 to 3, and n12 represents an integer of 1 to 3. 【Chemistry 2】 (In the formula, Ar １３ , Ar １５ , and Ar １６ each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar １４ , and Ar １７ each independently represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar １５ , Ar １６ and Ar １７ At least two of n13 represent a two- or three-ring monovalent or divalent aromatic hydrocarbon group, or a monovalent or divalent aromatic heterocyclic group. n13 represents an integer of 0 to 3, and n14, n15, n16, and n17 each independently represent an integer of 1 to 3. n15+n16+n17>n13+n14.

2. In claim 1, Ar １５ , Ar １６ and Ar １７ An organic compound in which at least two of the above are naphthalenes, and each naphthalene is bonded to another substituent at the 2-position.

3. In claim 1, Ar １６ and Ar １７ is an organic compound in which each naphthalene is bonded to the 2-position and has 2,2'-binaphthalene as a partial structure.

4. An organic compound represented by general formula (G1): 【Chemistry 3】 (In the formula, R １ ~R ４ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituent represented by the following general formula (G1-1): ５ ~R ８ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituent represented by the following general formula (G1-2): ５ ~R ８ At least one of Ar is a substituent represented by the following general formula (G1-2): １１ represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar １２ represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 14 to 30 carbon atoms, or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; n11 represents an integer of 0 to 3, and n12 represents an integer of 1 to 3. 【Chemistry 4】 (In the formula, Ar １３ , and Ar １５ each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar １４ and Ar １７ each independently represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar １５ , or Ar １７ At least one of is phenanthrene, and Ar １７ When n13 is phenanthrene, it is bonded to another group at the 2nd or 3rd position of the phenanthrene. n13 represents an integer of 0 to 3, and n14, n15, and n17 each independently represent an integer of 1 to 3. n15+n17>n13+n14.

5. In any one of claims 1 to 4, Ar １１ ~Ar １７ are organic compounds each independently representing an aromatic hydrocarbon group.

6. 5. The organic compound according to claim 1, wherein the deposition temperature is 330° C. or less.

7. An organic compound represented by structural formula (100), structural formula (101), structural formula (102), structural formula (123), or structural formula (150). 【Chemistry 5】

8. An electronic device comprising the organic compound according to any one of claims 1 to 4 and claim 7.

9. A light-emitting device having an organic compound having a carbazole ring and a phenanthrene ring in a cap layer.

10. A light emitting device having an organic compound having a carbazole ring and at least two and at most four naphthalene rings in a capping layer.

11. 11. A light-emitting device, wherein the organic compound according to claim 9 has an ordinary refractive index no of 1.9 or more and an ordinary extinction coefficient ko of 0.2 or less at 450 nm.

12. 11. A light-emitting device, wherein the organic compound according to claim 9 has an ordinary refractive index no of 1.8 or more and an ordinary extinction coefficient ko of 0.2 or less at 520 nm.

13. 11. A light-emitting device, wherein the organic compound according to claim 9 has an ordinary refractive index no of 1.75 or more and an ordinary extinction coefficient ko of 0.2 or less at 630 nm.

14. The organic compound represented by general formula (G1) is The organic compound has a difference between an ordinary refractive index no and an extraordinary refractive index ne of 0.1 or more and 0.4 or less at a wavelength of 360 nm or more and 830 nm or less. 【Chemistry 6】 (In the formula, R １ ~R ４ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituent represented by the following general formula (G1-1): ５ ~R ８ each independently represents any one of hydrogen (including deuterium), a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 6 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms, and a substituent represented by the following general formula (G1-3): ５ ~R ８ At least one of the groups represented by the following general formula (G1-3) is a substituent, １１ represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar １２ represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; n11 represents an integer of 0 to 3, and n12 represents an integer of 1 to 3. 【Chemistry 7】 (In the formula, Ar １３ , Ar １５ , and Ar １６ each independently represents a substituted or unsubstituted divalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted divalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar １４ , and Ar １７ each independently represents a substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms or a substituted or unsubstituted monovalent aromatic heterocyclic group having 3 to 30 carbon atoms; Ar １５ , Ar １６ and Ar １７ At least two of n13, n15, and n16 each independently represent an integer of 0 to 3, and n14 and n17 each independently represent an integer of 1 to 3. n15+n16+n17≧n13+n14.

15. 15. The light-emitting device according to claim 9, 10, or 14, wherein the deposition temperature of the organic compound is 330° C. or less.

16. A light-emitting device having an organic compound represented by the structural formula (100), the structural formula (101), the structural formula (102), the structural formula (123), or the structural formula (150). 【Chemistry 8】

17. 17. The light emitting device of claim 9, wherein the organic compound is a capping layer.

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