Light-emitting device and organic compound

Abstract

Provided is a light-emitting device that has excellent characteristics. Also provided is a novel organic compound. The light-emitting device includes a first electrode, a second electrode, and a light-emitting layer, wherein: the light-emitting layer is located between the first electrode and the second electrode; the light-emitting layer includes a first organic compound and a light-emitting substance; and the first organic compound has deuterium in a partial structure that greatly contributes to a lowest triplet excited state.

Description

Light-emitting devices and organic compounds

[0001] One aspect of the present invention relates to organic compounds, organic semiconductor elements, light-emitting devices, light-receiving devices, photodiode sensors, display modules, lighting modules, display devices, electronic equipment, lighting devices, and electronic devices. However, one aspect of the present invention is not limited to the above-mentioned technical fields. The technical fields of one aspect of the invention disclosed herein relate to products, methods, or methods of manufacturing. Alternatively, one aspect of the present invention relates to processes, machines, manufacturers, or compositions of matter. Therefore, more specifically, examples of the technical fields of one aspect of the present invention disclosed herein include semiconductor devices, display devices, liquid crystal display devices, lighting devices, energy storage devices, memory devices, imaging devices, methods for driving them, or methods for manufacturing them.

[0002] The practical application of organic electroluminescent devices (organic EL elements), such as light-emitting devices, light-receiving devices, and light-receiving / receiving devices, which utilize electroluminescence using organic compounds, is progressing.

[0003] For example, the basic configuration of a light-emitting device consists of an organic compound layer (EL layer) containing a light-emitting material sandwiched between a pair of electrodes. By applying a voltage to this device, carriers are injected, and by utilizing the recombination energy of these carriers, light emission can be obtained from the light-emitting material.

[0004] Furthermore, the basic configuration of a photodetector consists of an organic compound layer (active layer) containing a light-emitting material sandwiched between a pair of electrodes. This device absorbs light energy and generates carriers, thereby obtaining electrons from the photoelectric conversion material.

[0005] For example, a functional panel is known in which pixels provided in the display area are equipped with light-emitting elements (light-emitting devices) and photoelectric conversion elements (light-receiving devices) (Patent Document 1).

[0006] Furthermore, while the characteristics of organic EL devices have improved remarkably, they are still insufficient to meet the high demands for all characteristics, including efficiency and durability.

[0007] For example, a technique for replacing hydrogen atoms in a host material with deuterium atoms (deuteration) has been disclosed (Patent Document 2). Deuteration of host materials is effective in extending the lifespan of light-emitting devices, but the synthesis route becomes complicated and the cost of raw materials increases significantly. Alternatively, there are problems such as the need for high temperature and high pressure in the synthesis. Or, the purification process after the synthesis reaction becomes complicated, making it difficult to purify the organic compound that has been substituted with deuterium, and thus high purity cannot be achieved.

[0008] WO2020 / 152556 special table 2013-503860

[0009] One aspect of the present invention aims to provide a novel light-emitting device. Another aspect of the present invention aims to provide a light-emitting device with high luminous efficiency and good reliability.

[0010] One aspect of the present invention aims to provide a novel organic compound. Another aspect of the present invention aims to provide a method for synthesizing a novel organic compound. Another aspect of the present invention aims to provide a method for synthesizing an organic compound in which a portion of the organic compound is deuterated. Another aspect of the present invention aims to provide an organic compound that can achieve the effect of extending the lifespan of organic EL devices using a method for synthesizing an organic compound in which a portion of the organic compound is selectively deuterated.

[0011] Furthermore, one aspect of the present invention aims to provide an organic compound with a stable excited state. Another aspect of the present invention aims to provide an organic EL device with a long operating life. Another aspect of the present invention aims to provide an organic compound that can be used as a cap layer. Another aspect of the present invention aims to provide a novel organic EL device. Another aspect of the present invention aims to reduce the manufacturing cost of an organic EL device. Another aspect of the present invention aims to provide a light-emitting device, electronic device, or lighting device with low power consumption.

[0012] Furthermore, the description of these problems does not preclude the existence of other problems. Also, one aspect of the present invention does not need to solve all of these problems. Other problems will naturally become clear from the description in the specification, drawings, claims, etc., and it is possible to extract other problems from the description in the specification, drawings, claims, etc.

[0013] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound and a light-emitting substance, the first organic compound having deuterium in a substructure that contributes significantly to the lowest triplet excited state.

[0014] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has deuterium in a substructure that contributes greatly to the lowest triplet excited state and in a substructure that contributes greatly to the lowest singlet excited state.

[0015] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has deuterium in a substructure that contributes greatly to the lowest triplet excited state, the second organic compound has deuterium in a substructure that contributes greatly to the lowest triplet excited state, and the difference between the lowest triplet excited levels of the first organic compound and the second organic compound is 0.20 eV or less.

[0016] One aspect of the present invention has a first electrode, a second electrode, and a light-emitting layer. The light-emitting layer is located between the first electrode and the second electrode. The light-emitting layer has a first organic compound, a second organic compound, and a light-emitting substance. The first organic compound has deuterium in a partial structure that largely contributes to the lowest triplet excited state. The second organic compound has deuterium in a partial structure that largely contributes to the lowest triplet excited state and a partial structure that largely contributes to the lowest singlet excited state. The first organic compound and the second organic compound are light-emitting devices in which the difference in the lowest triplet excitation levels is 0.20 eV or less.

[0017] One aspect of the present invention has a first electrode, a second electrode, and a light-emitting layer. The light-emitting layer is located between the first electrode and the second electrode. The light-emitting layer has a first organic compound, a second organic compound, and a light-emitting substance. The first organic compound has deuterium in a partial structure that largely contributes to the lowest triplet excited state. The second organic compound is an organic compound represented by the general formula (G1). The first organic compound and the second organic compound are light-emitting devices in which the difference in the lowest triplet excitation levels is 0.20 eV or less.

[0018]

[0019] However, in the above general formula (G1), Ar １ and Ar ２ each independently represent an aryl group having 6 to 30 carbon atoms that forms a substituted or unsubstituted ring, and R １ to R ７ and R １１ to R １７ each independently represent hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. At least one of the hydrogens possessed by Ar １ , the hydrogens possessed by Ar ２ , and R １ to R ７ , R １１ to R １７ is deuterium.

[0020] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has a substructure that contributes significantly to the lowest triplet excited state, the second organic compound is an organic compound represented by general formula (G2), and the difference between the lowest triplet excited levels of the first and second organic compounds is 0.20 eV or less.

[0021]

[0022] However, in the above general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ Each independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms, R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ At least one of them is deuterium.

[0023] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has deuterium in a substructure that contributes greatly to the lowest triplet excited state, the second organic compound is an organic compound represented by general formula (G3), and the difference between the lowest triplet excited levels of the first organic compound and the second organic compound is 0.20 eV or less.

[0024]

[0025] However, in the general formula (G3), Ar １１ and Ar １２ Each of these is a group that can be independently represented by any one of the general formulas (Ar-1) to (Ar-4), and Ar １１ and Ar１２ They have the same fused ring, R ４１ ~R ５４ Each of these independently represents hydrogen (including deuterium), and the general formula (G3) has at least two or more deuterium atoms.

[0026]

[0027] However, in general formulas (Ar-1) to (Ar-4), R ６１ ~R ６７ , R ７１ ~R ７９ , R ８１ ~R ８９ , and R ９１ ~R １０１ Each of these independently represents hydrogen (including deuterium) or an alkyl group having 1 to 6 carbon atoms. In general formulas (Ar-1) to (Ar-4), the asterisk (*) indicates a bond with general formula (G3).

[0028] One aspect of the present invention is a light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has deuterium in a substructure that contributes significantly to the lowest triplet excited state, and the second organic compound is one of the organic compounds represented by structural formula (101) to structural formula (106), and the difference between the lowest triplet excited levels of the first organic compound and the second organic compound is 0.20 eV or less.

[0029]

[0030] One aspect of the present invention is an organic compound represented by the general formula (G2).

[0031]

[0032] However, in the general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Also, R １ ~R ７ And R １１ ~R １７ At least one of the following, and R ２１ ~R ２７ At least one of them is deuterium, R ２８ ~R ３２ At least one of them is light hydrogen.

[0033] Alternatively, in the general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Also, R １ ~R ７ And R １１ ~R １７ At least one of the following, and R ２８ ~R ３２ At least one of them is deuterium, R ２１ ~R ２７ At least one of them is light hydrogen.

[0034] Alternatively, in the general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Also, R １ ~R ７ And R ２１ ~R ２７ At least one of them is deuterium, R １１ ~R １７ At least one of the following and R ２８ ~R ３２At least one of them is light hydrogen.

[0035] One aspect of the present invention is an organic compound represented by structural formulas (100) to (106).

[0036]

[0037] Alternatively, another aspect of the present invention is an electronic device having the above-mentioned light-emitting device or light-receiving device and a sensor, an operation button, a speaker, or a microphone.

[0038] Alternatively, another aspect of the present invention is a lighting device having the above-mentioned light-emitting device or light-receiving device and a housing.

[0039] According to one aspect of the present invention, a novel light-emitting device can be provided. Furthermore, according to one aspect of the present invention, a light-emitting device with high luminous efficiency and good reliability can be provided.

[0040] According to one aspect of the present invention, a novel organic compound can be provided. Furthermore, according to one aspect of the present invention, a method for synthesizing a novel organic compound can be provided. Furthermore, according to one aspect of the present invention, a method for synthesizing an organic compound in which a portion of the organic compound is deuterated can be provided. Furthermore, according to one aspect of the present invention, an organic compound can be provided that, using a method for synthesizing an organic compound in which a portion of the organic compound is selectively deuterated, can be used to obtain an organic compound that has the effect of extending the lifespan of an organic EL device or a photodetector.

[0041] Furthermore, one aspect of the present invention can provide an organic compound with a stable excited state. Furthermore, one aspect of the present invention can provide an organic compound that can be used in an organic EL device or a photodetector. Furthermore, one aspect of the present invention can provide an organic compound that can be used in the carrier transport layer of an organic EL device. Furthermore, one aspect of the present invention can provide an organic compound that can be used in the cap layer of a light-emitting device. Furthermore, one aspect of the present invention can provide a novel organic EL device. Furthermore, one aspect of the present invention can provide an organic EL device with a long operating life. Furthermore, one aspect of the present invention can reduce the manufacturing cost of an organic EL device. Furthermore, one aspect of the present invention can provide a light-emitting device, electronic device, or lighting device with low power consumption.

[0042] Furthermore, the description of these effects does not preclude the existence of other effects. Moreover, one aspect of the present invention does not necessarily have to possess all of these effects. Other effects will naturally become apparent from the description in the specification, drawings, and claims, and it is possible to extract other effects from the description in the specification, drawings, and claims.

[0043] Figures 1A and 1B are schematic diagrams of a light-emitting device. Figure 2 is a diagram illustrating the method for calculating the light emission lifetime. Figure 3 is a diagram illustrating the method for calculating the light emission lifetime. Figures 4A and 4B are diagrams illustrating the calculation results. Figures 5A, 5B, 5C, 5D, and 5E are diagrams illustrating the configuration of a light-emitting device. Figures 6A and 6B are top views and cross-sectional views of the light-emitting device. Figures 7A, 7B, 7C, 7D, 7E, 7F, and 7G are top views showing examples of pixel configurations. Figures 8A, 8B, 8C, 8D, 8E, 8F, 8G, 8H, and 8I are top views showing examples of pixel configurations. Figures 9A and 9B are perspective views showing examples of display module configurations. Figures 10A and 10B are cross-sectional views showing examples of display device configurations. Figure 11 is a perspective view showing an example of display device configuration. Figure 12 is a cross-sectional view showing an example of display device configuration. Figure 13 is a cross-sectional view showing an example of display device configuration. Figure 14A is a cross-sectional view showing an example of the configuration of a display device, and Figures 14B and 14C are top views showing an example of the configuration of a display device. Figure 15 is a cross-sectional view showing an example of the configuration of a display device. Figure 16A is a cross-sectional view showing an example of the configuration of a display device, and Figures 16B and 16C are top views showing an example of the configuration of a display device. Figures 17A, 17B, 17C, and 17D are diagrams showing an example of electronic equipment. Figures 18A, 18B, 18C, 18D, 18E, and 18F are diagrams showing an example of electronic equipment. Figures 19A, 19B, 19C, 19D, 19E, 19F, and 19G are diagrams showing an example of electronic equipment. Figure 20 is a diagram illustrating the absorption and emission spectra of an organic compound in a toluene solution. Figure 21 is a diagram illustrating the absorption and emission spectra of an organic compound in a thin film. Figure 22 is a diagram illustrating the configuration of a light-emitting device. Figure 23 is a diagram illustrating the luminance-current density characteristics of a light-emitting device. Figure 24 is a diagram illustrating the luminance-voltage characteristics of a light-emitting device. Figure 25 illustrates the current efficiency-luminance characteristics of the light-emitting device. Figure 26 illustrates the current density-voltage characteristics of the light-emitting device. Figure 27 illustrates the field emission spectrum of the light-emitting device. Figure 28 illustrates the change in luminance with respect to the operating time of the light-emitting device.Figure 29 is a diagram illustrating the reliability improvement rate of the light-emitting device. Figure 30 is a diagram illustrating the brightness-current density characteristics of the light-emitting device. Figure 31 is a diagram illustrating the brightness-voltage characteristics of the light-emitting device. Figure 32 is a diagram illustrating the current efficiency-brightness characteristics of the light-emitting device. Figure 33 is a diagram illustrating the current density-voltage characteristics of the light-emitting device. Figure 34 is a diagram illustrating the electroluminescence spectrum of the light-emitting device. Figure 35 is a diagram illustrating the change in brightness with respect to the operating time of the light-emitting device. Figure 36 is a diagram illustrating the reliability improvement rate of the light-emitting device. Figure 37 is a diagram illustrating the brightness-current density characteristics of the light-emitting device. Figure 38 is a diagram illustrating the brightness-voltage characteristics of the light-emitting device. Figure 39 is a diagram illustrating the current efficiency-brightness characteristics of the light-emitting device. Figure 40 is a diagram illustrating the current density-voltage characteristics of the light-emitting device. Figure 41 is a diagram illustrating the electroluminescence spectrum of the light-emitting device. Figure 42 is a diagram illustrating the reliability improvement rate of the light-emitting device. Figure 43 is a diagram illustrating the brightness-current density characteristics of the light-emitting device. Figure 44 is a diagram illustrating the brightness-voltage characteristics of the light-emitting device. Figure 45 is a diagram illustrating the current efficiency-brightness characteristics of the light-emitting device. Figure 46 illustrates the current density-voltage characteristics of the light-emitting device. Figure 47 illustrates the electroluminescence spectrum of the light-emitting device. Figure 48 illustrates the reliability improvement rate of the light-emitting device.

[0044] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the following description, and its form and details can be modified in various ways without departing from the spirit and scope of the present invention. Accordingly, the present invention shall not be interpreted as being limited to the contents of the embodiments shown below.

[0045] In this specification, "deuterated organic compound" refers to an organic compound in which, when focusing on hydrogen atoms (including deuterium) at specific positions within the organic compound, the proportion of deuterium (including deuterium) is greater than the natural abundance of deuterium. This proportion is preferably sufficiently greater than the natural abundance. "Sufficiently" means, for example, that 7.5% or more is deuterated. The deuteration of an organic compound can be confirmed by methods such as nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry.

[0046] Please note that the positions, sizes, and ranges of each component shown in the drawings may not represent their actual positions, sizes, and ranges for the sake of ease of understanding. Therefore, the disclosed invention is not necessarily limited to the positions, sizes, and ranges disclosed in the drawings.

[0047] Furthermore, in this specification and other documents, when describing the structure of the invention using drawings, reference numerals that refer to the same thing will be used consistently across different drawings.

[0048] (Embodiment 1) This embodiment describes a light-emitting device in which an organic compound having deuterium, which is one aspect of the present invention, is used as the host material for the light-emitting layer.

[0049] <Example of Light-Emitting Device Configuration> Figure 1A is a schematic cross-sectional view of a light-emitting device 10 according to one embodiment of the present invention. The light-emitting device 10 has a pair of electrodes (a first electrode 101 and a second electrode 102) and an organic compound layer 103 provided between the pair of electrodes. The organic compound layer 103 has at least a light-emitting layer 113. In this embodiment 1, the organic compound layer 103 also has a hole transport layer 112.

[0050] Furthermore, the organic compound layer 103 shown in Figure 1A has functional layers such as a hole injection layer 111, a hole transport layer 112, an electron transport layer 114, and an electron injection layer 115, in addition to the light-emitting layer 113.

[0051] In this embodiment, the first electrode 101 is described as the anode and the second electrode 102 as the cathode, but the configuration of the light-emitting device 10 is not limited to this. In other words, the first electrode 101 may be the cathode and the second electrode 102 as the anode, and the stacking order of the layers between the electrodes may be reversed. That is, the stacking order from the anode side may be the hole injection layer 111, the hole transport layer 112, the light-emitting layer 113, the electron transport layer 114, and the electron injection layer 115.

[0052] The configuration of the organic compound layer 103 is not limited to the configuration shown in Figure 1A, and may include at least one selected from the hole injection layer 111, hole transport layer 112, electron transport layer 114, and electron injection layer 115. Alternatively, the organic compound layer 103 may include a functional layer that has functions such as reducing the hole or electron injection barrier, improving hole or electron transport, inhibiting hole or electron transport, or suppressing quenching by electrodes. Each functional layer may be a single layer or a configuration in which multiple layers are stacked.

[0053] Figure 1B is a schematic cross-sectional view showing an example of the light-emitting layer 113 shown in Figure 1A. The light-emitting layer 113 shown in Figure 1B comprises a host material 118 (organic compound 118_1 and organic compound 118_2) and a guest material 119 (luminescent substance). Note that organic compound 118_1 and organic compound 118_2 may be the same compound, in which case the host material 118 used in the light-emitting layer is one type of material.

[0054] As the guest material 119, any luminescent organic compound may be used. Both fluorescent substances (hereinafter also referred to as fluorescent compounds) and phosphorescent substances (hereinafter also referred to as phosphorescent compounds) are suitably used as the luminescent organic compound. In particular, for blue devices, fluorescent substances are preferred because they provide superior reliability for the light-emitting device, while for green and red devices, phosphorescent compounds are preferred from the viewpoint of luminescence efficiency and power consumption.

[0055] Furthermore, when a phosphorescent compound is used as a guest material in the light-emitting layer 113, the host material 118 is present in the largest amount by weight, and the guest material 119 is dispersed within the host material 118. In this case, it is preferable that the host material 118 (organic compound 118_1 and organic compound 118_2) in the light-emitting layer 113 forms an excited complex (also called an exciplex). An excited complex is an excited state consisting of two or more substances, and in the case of photoexcitation, it is formed by the interaction of one of the excited substances with the other substance in the ground state.

[0056] Furthermore, in the light-emitting layer 113, when a fluorescent compound is used as the guest material, the host material 118 is present in the largest amount by weight, and the guest material 119 is dispersed within the host material 118. As mentioned above, the lowest triplet excitation level (T) of the host material 118 (organic compound 118_1 and organic compound 118_2) in the light-emitting layer 113 １ The level is the T of the guest material 119 of the light-emitting layer 113. １ A level lower than the current level is preferable because it increases the delayed fluorescence component due to TTA (Triple-Triple Annihilation), thereby improving luminescence efficiency. In a light-emitting device using a fluorescent luminescence layer, the host material 118 of the luminescence layer may be of one type, in which case organic compound 118_1 and organic compound 118_2 are the same material. In addition, in a light-emitting device using a fluorescent luminescence layer, two types of host material 118 of the luminescence layer may be used. Furthermore, a laminated luminescence layer may be formed by dispersing the same or different fluorescent compounds in two different host materials. When laminating luminescence layers, one or two types of host material may be used for each layer.

[0057] Here, the host material 118 is in at least a minimum triplet excited state (T １ By using a compound in which a substructure that contributes significantly to luminescence is deuterated, it is possible to obtain a highly reliable light-emitting device that achieves high luminescence efficiency while suppressing degradation.

[0058] Here, in the light-emitting device of one aspect of the present invention, the improvement in the energy transfer efficiency due to one or both of the first host material and the second host material having deuterium is attributed to the fact that the phosphorescence lifetime or delayed fluorescence lifetime of the deuterated organic compound is longer than the phosphorescence lifetime or delayed fluorescence lifetime of the non-deuterated organic compound. This is because the intramolecular vibration in the lowest triplet excited state (T １ state) of the deuterated organic compound is more suppressed than the intramolecular vibration of the non-deuterated organic compound, and the non-radiative transition from the T １ state to a more stable state is suppressed.

[0059] The energy transfer efficiency φ ＥＴ from the energy donor (excimer in one aspect of the present invention) to the energy acceptor (substance capable of converting triplet excitation energy into light emission in one aspect of the present invention) is represented by the following formula (1). From this formula, in order to increase the energy transfer efficiency φ ＥＴ , it can be seen that the rate constant k ｈ＊→ｇ of energy transfer should be increased, and the other competing rate constants k ｒ +k ｎｒ (=1 / τ) should be relatively small.

[0060] In formula (1), k ｒ represents the rate constant of the light emission process of the energy donor (fluorescence when discussing energy transfer from the singlet excited state, phosphorescence or delayed fluorescence when discussing energy transfer from the triplet excited state), k ｎｒ represents the rate constant of the non-light emission process (thermal deactivation and intersystem crossing) of the energy donor, and τ represents the measured lifetime of the excited state of the energy donor. Also, k ｈ＊→ｇ represents the rate constant of energy transfer (Förster mechanism or Dexter mechanism) from the energy donor to the energy acceptor.

[0061]

[0062] The rate constant k ｈ＊→ｇIn an organic compound that is not a deuterated organic compound, since the atomic arrangement, spectral shape, etc. of the molecule hardly change, they are almost the same (see the following formula (2) or formula (3)). Therefore, in the comparison with an organic compound that is not a deuterated organic compound, the rate constant k of energy transfer from an energy donor to an energy acceptor ｈ＊→ｇ is found to be greatly affected by the luminescence lifetime (phosphorescence lifetime or delayed fluorescence lifetime) τ. That is, as the luminescence lifetime (phosphorescence lifetime or delayed fluorescence lifetime) of the energy donor becomes longer, the energy transfer efficiency from the energy donor to the energy acceptor improves.

[0063]

[0064]

[0065] Formula (2) is the rate constant k from an energy donor to an energy acceptor in the Förster mechanism, and formula (3) is that in the Dexter mechanism ｈ＊→ｇ of the formula.

[0066] In formula (2), ν represents the frequency, and f′ ｈ (ν) represents the normalized emission spectrum of the host material or an exciplex composed of two or more host materials (fluorescence spectrum when discussing energy transfer from the singlet excited state, phosphorescence spectrum when discussing energy transfer from the triplet excited state), ε ｇ (ν) represents the molar absorption coefficient of the energy acceptor, N represents Avogadro's number, n represents the refractive index of the host material, R represents the intermolecular distance between the host material and the guest material, τ represents the measured emission lifetime (fluorescence lifetime, phosphorescence lifetime) of the excited state of the energy donor, φ represents the emission quantum yield of the energy donor (fluorescence quantum yield when discussing energy transfer from the singlet excited state, phosphorescence quantum yield when discussing energy transfer from the triplet excited state), and K ２ is a coefficient (0 to 4) representing the orientation of the transition dipole moments of the host material and the guest material. In the case of random orientation, K ２ = 2 / 3.

[0067] In equation (3), h is Planck's constant, K is a constant with the dimension of energy, ν represents the frequency, and f' ｈ (ν) represents the normalized emission spectrum of the excited complex consisting of the host material or two or more host materials (fluorescence spectrum when discussing energy transfer from the singlet excited state, phosphorescence spectrum when discussing energy transfer from the triplet excited state), and ε′ ｇ (ν) represents the normalized absorption spectrum of the energy acceptor, L represents the effective Bohr radius, and R represents the intermolecular distance between the host and guest materials.

[0068] As described above, the energy transfer efficiency from each triplet excited state is important in the energy transfer from the first and second host materials, and therefore the lifetime of the triplet excited state is important. In other words, by deuterizing one or both of the first and second host materials, the phosphorescence lifetime or delayed fluorescence lifetime is extended, improving energy transfer efficiency and suppressing the degradation of the deuterated organic compound. As a result, light-emitting devices with energy donors using deuterated organic compounds exhibit less degradation of the organic compound than light-emitting devices with energy donors that do not use deuterated organic compounds, resulting in more reliable light-emitting devices.

[0069] The phosphorescence lifetime and delayed fluorescence lifetime are calculated by measuring the transient PL (luminescence emission) using time-resolved measurements, which involve measuring the intensity of the luminescence as it decays after the excitation light is blocked by a shutter at regular intervals. In this case, fluorescence components may be mixed in during the initial decay phase, resulting in a graph that is not linear. In such cases, the starting point can be determined at the point where the graph becomes linear, and the time it takes for the intensity at the starting point to decay to 1 / e can be defined as the phosphorescence lifetime or delayed fluorescence lifetime.

[0070] Furthermore, if the light emitted by a substance that can convert triplet excitation energy into light emission (a light-emitting substance contained in the light-emitting layer) is in the green region, that is, if its peak wavelength is typically between 500 nm and 600 nm, the first host material is preferably an organic compound whose phosphorescence lifetime or delayed fluorescence lifetime is 1.50 times or more than that of the first material in which the deuterium of the first host material is hydrogen. Furthermore, the second host material is preferably an organic compound whose phosphorescence lifetime or delayed fluorescence lifetime is 3.00 times or more than that of the second material in which the deuterium of the second host material is hydrogen. Furthermore, it is preferable that the product of X and Y is 4.50 or greater when the phosphorescence lifetime or delayed fluorescence lifetime of the first host material is X times the phosphorescence lifetime or delayed fluorescence lifetime of the first material in which the deuterium of the first host material is hydrogen, and the phosphorescence lifetime or delayed fluorescence lifetime of the second host material is Y times the phosphorescence lifetime or delayed fluorescence lifetime of the second material in which the deuterium of the second host material is hydrogen.

[0071] As shown in Figure 2, the starting point is determined within the range where the graph is a straight line from the measurement data (Figure 2 left), and time t=0 is set (here, t=0 is defined as the time when the light intensity reaches 50% of the initial intensity) (Figure 2 right). The time from there until the light intensity decays to 1 / e of the intensity at t=0 is defined as the phosphorescence lifetime or delayed fluorescence lifetime. In Figure 2, the time when the measurement data reaches 50% of the initial intensity is set as time 0s, and when the light intensity at 0s is set to 1, the time when that light intensity becomes 1 / e is the phosphorescence lifetime or delayed fluorescence lifetime. Note that while 50% of the initial intensity is a convenient starting point, other values ​​can also be used.

[0072] Specifically, Figure 3 shows the results of calculating the phosphorescence lifetime of 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviated as βNCCP) and 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9'-(phenyl-2,3,4,5,6-d5)-3,3'-bi-9H-carbazole-1,1',2,2',4,4',5,5',6,6',7,7',8,8'-d14 (abbreviated as βNCCP-d26), which contains deuterium. It can be seen that βNCCP-d26, which contains deuterium, has a longer phosphorescence lifetime than βNCCP.

[0073] The phosphorescence lifetime can be measured at liquid nitrogen temperature (77K) using a fluorometer such as the FP-8600 manufactured by JASCO Corporation, equipped with a liquid nitrogen cooling unit. The solution preparation of the material is performed in a glove box, and the sample is dissolved in deoxygenated 2-methyltetrahydrofuran (abbreviated as 2-MeTHF), stirred with a stirrer at room temperature for about 30 minutes (heating is also performed for materials that are difficult to dissolve), resulting in 1.2 × 10⁻⁶ −４ You can prepare and use a solution of approximately M concentration.

[0074] Time-resolved measurements can be performed by irradiating the sample cell with excitation light for about 30 seconds, blocking the excitation light with a shutter, and then measuring the intensity of the decaying emission at 10 ms intervals. The wavelength used for phosphorescence lifetime measurement is preferably the peak wavelength of the phosphorescence spectrum. If there are multiple phosphorescence spectrum peaks, the one with the higher peak intensity is preferable. Depending on the wavelength, fluorescence spectra may be mixed in, making accurate measurement impossible. In such cases, it is preferable to compare the emission spectrum measured at low temperature (e.g., 77 K) (emission spectrum containing phosphorescence) with the emission spectrum measured at room temperature (emission spectrum containing only fluorescence and no phosphorescence) and select a wavelength in which fluorescence emission spectra are less likely to be included. Alternatively, the longest wavelength peak wavelength among the phosphorescence spectrum peaks can be selected. When using a solid sample obtained by freezing a solution, emission from states other than the lowest triplet excited state may also be observed. In this case, the longest wavelength peak should be selected.

[0075] The excitation wavelength can be appropriately selected within a wavelength range where the solvent does not have an effect. If the material can be sufficiently excited, it is preferable to use excitation light of 330 nm for measurement because the influence of solvent emission is minimized. The bandwidth of the excitation light and observation light can be around 10 nm. Ideally, since the emission decays in a single exponential function, the starting point can be determined at the point where the graph becomes a straight line, and the time until the intensity at the starting point decays to 1 / e can be defined as the phosphorescence lifetime or delayed fluorescence lifetime.

[0076] Fluorescence lifetime, phosphorescence lifetime, and delayed fluorescence lifetime can be distinguished by the length of the lifetime measured using time-resolved measurements. Emission lifetimes of nanoseconds (n) or less than 1 microsecond are considered to be fluorescence lifetimes, while emission lifetimes of microseconds (μ) to milliseconds (m) or longer are considered to be phosphorescence lifetimes and delayed fluorescence lifetimes.

[0077] In one embodiment of the present invention, the reliability of the light-emitting device is improved according to the phosphorescence lifetimes of the first and second host materials, i.e., the length of the phosphorescence lifetime of the triplet exciton. The lengthening of the phosphorescence lifetime of the triplet exciton is due to the suppression of non-radiative deactivation of the triplet excitation energy, which is caused by the suppression of vibrations due to deuteration. At this time, the lowest triplet excitation level of the first host material (T １ (Level) and T of the second host material １ A small difference in energy levels is preferable because it prevents the excitation energy from being biased towards one of the organic compounds, thus preventing significant degradation of one of them and improving the reliability of the light-emitting device. Specifically, the T of the first host material １ Level and T of the second host material １ The difference between the energy levels is preferably 0.20 eV or less, more preferably 0.15 eV or less, and more preferably 0.10 eV or less.

[0078] Note, - １ As an indicator of the energy level, the phosphorescence component (phosphor spectrum) of the PL spectrum observed at low temperatures (for example, any temperature in the range of 4K to 80K) can be used. Specifically, for example, a thin film in which a 50 nm layer of the sample is deposited on a quartz substrate is used, the emission spectrum (phosphor spectrum) is measured at a measurement temperature of 10K, and the energy at the short-wavelength emission edge is defined as T. １This can be considered as an energy level. For measurement, it is preferable to use a LabRAM HR-PL micro-PL system (Horiba, Ltd.) and a He-Cd laser (325 nm) as the excitation light. The emission edge can be calculated by drawing a tangent line at the point where the slope on the shortest wavelength side of the shortest wavelength peak (or shoulder peak) observed in the emission spectrum (phosphorescence spectrum) is maximum, and then finding the intersection of this tangent line with the horizontal axis (wavelength) or baseline.

[0079] Also, the T of phosphorescent materials １ The energy level is determined by measuring the emission spectrum (PL spectrum) observed at low temperatures (e.g., any temperature in the range of 4K to 80K) or room temperature (e.g., any temperature in the range of 275K to 305K), and determining the energy at the short-wavelength emission edge. １ It can be considered a level.

[0080] Furthermore, it is preferable that the photoluminescence (PL) spectra of the excited complex formed from the first and second host materials overlap with the PL spectrum of the luminescent substance (a substance capable of converting triplet energy into light emission). This is because the excitation energy of the energy donor and the excitation energy of the luminescent substance are close, which allows for a reduction in the driving voltage of the light-emitting device. For this reason, it is preferable that the difference between their respective maximum peak wavelengths is 30 nm or less. Alternatively, a light-emitting device having a configuration in which the difference between the wavelength of the short-wavelength emission edge in the PL spectrum of the excited complex and the wavelength of the short-wavelength emission edge in the PL spectrum of the luminescent substance is 30 nm or less is preferable because it can reduce the driving voltage, provide a device with high luminescence efficiency, and provide a highly reliable light-emitting element.

[0081] The PL spectrum of the excited complex is preferably measured using a co-evaporated film of the first and second host materials. When measuring the PL spectrum of a luminescent substance (a substance that can convert triplet energy into light emission), the sample form may be a thin film or a solution, but a solution is preferred from the viewpoint of verifying the state of isolated molecules. There are no particular restrictions on the solvent of the solution as long as the same solvent is used for comparison, but a solvent with relatively low polarity, such as toluene or chloroform, is preferred.

[0082] <Calculation method and conditions for identifying substructures contributing to excited states> In organic compounds, the lowest triplet excited state (T １ ), and the lowest singlet excited state (S １ The identification of substructures that contribute significantly to ) can be analyzed using quantum chemical calculations. Examples of such calculation methods include density functional theory (DFT), time-dependent density functional theory (TDDFT), Tamm-Dancoff approximation (TDA), and configuration interaction method (CI).

[0083] Specifically, for 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviated as βNCCP) shown below, we used quantum chemical calculations to analyze the substructures that contribute most to the lowest triplet excited state and the lowest singlet excited state.

[0084]

[0085] Gaussian 16 was used as the quantum chemical calculation program. For the calculation conditions, the CAM-B3LYP mixed functional, which takes long-range corrections into account, was used to define the parameters related to exchange and correlation energies. Furthermore, 6-311G (a basis set for a triple-split valence basis system using three shortened functions for each valence orbital) was used as the basis set. Additionally, a p-function was added for hydrogen atoms and a d-function for non-hydrogen atoms as the polarization basis set.

[0086] <lowest triplet excited state (T １ Analysis of substructures that contribute significantly to ) > Here, DFT is used to analyze the lowest triplet excited state of βNCCP (T １ We investigated the substructures that contribute significantly to ).In the calculations, the lowest triplet excited state (T １ The structure of βNCCP was optimized, and its spin density distribution was analyzed. The calculated spin density distribution is shown in Figure 4A. In the figure, the region enclosed by the dashed line 91 is the naphthyl group, and the region enclosed by the dotted line 92 is the carbazolyl group. Furthermore, the region enclosed by the dotted line in the naphthyl group represents the spin density distribution.

[0087] In the calculation results, the substructure with the largest absolute value of spin density is the lowest triplet excited state (T １ It can be determined that the contribution to the lowest triplet excited state (T) is greater, and a larger absolute value of spin density results in a larger spin density distribution. In βNCCP, when comparing substituents, the naphthyl group has a larger spin density distribution than the carbazolyl group. Therefore, the substructure of the naphthyl group is greater than the substructure of the carbazolyl group in terms of the lowest triplet excited state (T). １ It can be seen that the contribution to ) is greater. Note that the display of the spin density distribution changes depending on the display threshold, so by appropriately adjusting the display threshold, the lowest triplet excited state (T) can be shown. １ This allows us to select substructures that contribute more to ).

[0088] Also, the lowest triplet excited state (T １ As an effective method for investigating substructures that contribute significantly to (S), in addition to the spin density distribution, analysis of the magnitude of the absolute value of the Mulliken spin of each atom, analysis of the transition density distribution, or the ground state (S ０ ) and the lowest triplet excited state (T １ Examples include the analysis of the differential electron density distribution.

[0089] <Lowest singlet excited state (S １ Analysis of substructures that contribute significantly to ) Next, using TDDFT, the lowest singlet excited state of βNCCP (S １ We investigated the substructures that contribute significantly to ).In the calculations, the lowest singlet excited state (S １The structure of βNCCP was optimized, and the differential electron density distribution was analyzed. The calculated differential electron density distribution is shown in Figure 4B. In the figure, the region 91 enclosed by the dashed line on the left is the naphthyl group, the region 93 enclosed by the dashed line on the right is the phenyl group, and the region 92 enclosed by the dotted line is the carbazolyl group. Furthermore, the multiple regions enclosed by solid lines in the carbazolyl group represent the differential electron density distribution.

[0090] In the calculation results, the substructure with the largest absolute value of the differential electron density is the lowest singlet excited state (S １ It can be determined that the contribution to the differential electron density is greater, and a larger absolute value of the differential electron density results in a larger differential electron density distribution. In βNCCP, when comparing substituents, the differential electron density distribution is larger for the carbazolyl group than for the naphthyl group and the phenyl group. Therefore, the substructure of the carbazolyl group has a lower minimum singlet excited state (S) than the substructures of the naphthyl group and the phenyl group. １ It can be seen that the contribution is greater to ). Note that the display of the differential electron density distribution changes with the display threshold, so by appropriately adjusting the display threshold, the lowest singlet excited state (S １ This allows us to select substructures that contribute more to ).

[0091] Also, the lowest singlet excited state (S １ In addition to the differential electron density distribution, effective methods for investigating substructures that contribute significantly to this include analyzing the transition density, which corresponds to the overlap of molecular orbitals involved in electron transitions.

[0092] As described above, in organic compounds, the lowest triplet excited state (T １ ), and the lowest singlet excited state (S １ Substructures that contribute significantly to the lowest triplet excited state (T) can be analyzed using quantum chemical calculations. In organic compounds used in light-emitting devices, the lowest triplet excited state (T) １ ), and the lowest singlet excited state (S １Selectively deuterating substructures that contribute significantly to the lowest triplet excited state (T) or substituents containing such substructures is effective in improving the characteristics and reliability of light-emitting devices. Furthermore, by selectively deuterating only the substructures that contribute significantly to the lowest triplet excited state and the lowest singlet excited state, the deuteration of other substructures can be reduced, which also contributes to reducing the cost of supplying the material. In other words, significant effects can be obtained with minimal effort or cost. Moreover, when designing new materials, it is also possible to pre-deuterate the lowest triplet excited state (T) １ ), or the lowest singlet excited state (S １ ) can be calculated and used as a guideline for determining the substructure in which deuterium is introduced, shortening the time required for material development and greatly contributing to rapid development. Furthermore, since the electronic state is the same for organic compounds to which light hydrogen is bonded and organic compounds to which deuterium is bonded, the lowest triplet excited state (T １ ), and the lowest singlet excited state (S １ The substructures that contribute most significantly to this are the same.

[0093] Furthermore, in organic compounds, the lowest triplet excited state (T １ ) a triplet excited state higher than (hereinafter referred to as a higher triplet excited state (T ｎ ) and the lowest triplet excited state (T １ In organic compounds where the difference in energy levels with ) is 0.10 eV or less, the triplet excited state (T ｎ By using organic compounds in light-emitting devices that have a substructure that contributes significantly to the high-level triplet excited state (T), or a substituent containing the substructure that has been deuterated, the characteristics and reliability of the light-emitting device can be improved. In particular, the high-level triplet excited state (T ｎ ) and the lowest triplet excited state (T １ If the difference in energy levels with ) is 0.03 eV or less, then the higher triplet excited state (T) is at room temperature. ｎ The probability of generating a higher triplet excited state (T) increases. ｎ It is preferable to deuterate the substructures that contribute significantly to ) or substituents that include substructures.

[0094] Also, the lowest singlet excited state (S １) higher singlet excited states (hereinafter referred to as higher singlet excited states (S ｎ ) and the lowest singlet excited state (S １ In organic compounds where the difference in energy levels with ) is 0.10 eV or less, the singlet excited state (S ｎ By using organic compounds in light-emitting devices that have a substructure that contributes significantly to the high-level singlet excited state (S), or a substituent containing the substructure that has been deuterated, the characteristics and reliability of the light-emitting device can be improved. In particular, the high-level singlet excited state (S ｎ ) and the lowest singlet excited state (S １ If the difference in energy levels with ) is 0.03 eV or less, then at room temperature, the higher singlet excited state (S ｎ The probability of generating a higher singlet excited state (S) increases. ｎ It is preferable to deuterate a substructure that contributes significantly to ) or a substituent that includes a substructure.

[0095] Examples of deuterated compounds used as host materials include, but are not limited to, those with the following general formulas (G1) to (G3).

[0096] An organic compound that can be used in one aspect of the present invention can be represented by the general formula (G1).

[0097]

[0098] In general formula (G1), Ar １ and Ar ２ Each of these independently represents an aryl group with 6 to 30 carbon atoms that forms a substituted or unsubstituted ring, and R １ ~R ７ and R １１ ~R １７ Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms, and the general formula (G1) has one or more deuterium atoms.

[0099] Furthermore, an organic compound that can be used in one aspect of the present invention can be represented by the general formula (G2).

[0100]

[0101] In the general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms, and the general formula (G2) has one or more deuterium atoms.

[0102] Furthermore, an organic compound that can be used in one aspect of the present invention can be represented by the general formula (G3).

[0103]

[0104] In the general formula (G3), Ar １１ and Ar １２ Each of these is a group that can be independently represented by any one of the general formulas (Ar-1) to (Ar-4), and Ar １１ and Ar １２ They have the same fused ring, R ４１ ~R ５４ Each of these independently represents hydrogen (including deuterium), and the general formula (G3) has at least one deuterium.

[0105]

[0106] In the general formulas (Ar-1) to (Ar-4), R ６１ ~R ６７ , R ７１ ~R ７９ , R ８１ ~R ８９ , and R ９１ ~R １０１ Each of these independently represents hydrogen (including deuterium) or an alkyl group having 1 to 6 carbon atoms. In general formulas (Ar-1) to (Ar-4), the asterisk (*) indicates a bond with general formula (G3).

[0107] Furthermore, in general formulas (G1) to (G3), Ar １ Ar ２ , or R ｍ Specific examples of substituents represented by (where m is any natural number) are shown below.

[0108] Specifically, examples of aryl groups include phenyl, biphenylyl, terphenylyl, anthryl, tetracenyl, fluorenyl, dibenzofluorenyl, dimethylfluorenyl, diphenylfluorenyl, spirobifluorenyl, pyrenyl, perilenyl, tetracenyl, chrysenyl, phenanthryl, and triphenylenyl groups, and these aryl groups may have substituents.

[0109] Furthermore, if the above aryl group has substituents, the substituents can be selected from C1 to C6 alkyl groups, C3 to C6 cycloalkyl groups, or C6 to C13 aryl groups. Specific examples of such substituents include cyano groups and hydroxyl groups. Specifically, examples of C1 to C6 alkyl groups include methyl groups, ethyl groups, propyl groups, isopropyl groups, butyl groups, isobutyl groups, tert-butyl groups, pentyl groups, neopentyl groups, isopentyl groups, and n-hexyl groups. Examples of C3 to C6 cycloalkyl groups include cyclopropyl groups, cyclobutyl groups, cyclopentyl groups, and cyclohexyl groups. Examples of C6 to C13 aryl groups include phenyl groups, naphthyl groups, and fluorenyl groups. The substituents on the above aryl group may also contain deuterium.

[0110] Also, Ar １ or Ar ２ The structural formulas (Ar-1) to (Ar-4) described above can be used as such.

[0111] Examples of linear or branched alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, neohexyl group, 3-methylpentyl group, 2-methylpentyl group, 2-ethylbutyl group, 1,2-dimethylbutyl group, 2,3-dimethylbutyl group, octyl group, isooctyl group, sec-octyl group, tert-octyl group, nonyl group, isononyl group, sec-nonyl group, tert-nonyl group, decanyl group, isodecanyl group, sec-decanyl group, tert-decanyl group, and the like.

[0112] Examples of cycloalkyl groups include cyclopropyl, cyclohexyl, norbornyl, decahydronaphthyl, and adamantyl groups.

[0113] <Specific Examples> Next, specific examples of organic compounds that are one aspect of the present invention and have the configuration represented by the above general formulas (G1) to (G3) are shown below.

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126] The organic compounds represented by structural formulas (100) to (141) and structural formulas (200) to (291) are examples of organic compounds represented by any of the general formulas (G1) to (G3), but the organic compounds of one aspect of the present invention are not limited thereto.

[0127] Furthermore, the deuteration rate of each deuterium in the organic compounds shown in structural formulas (100) to (141) and structural formulas (200) to (291) is preferably 80% or more, but may be less than 100%.

[0128] For example, using deuterized organic compounds as materials for light-emitting devices can extend the operating life of these devices. Therefore, by using deuterized organic compounds, it is possible to provide light-emitting devices with long operating lives, which contributes to providing highly reliable electronic equipment and lowering device costs for consumers. In addition, deuterized light-emitting materials generally tend to have improved luminous efficiency, making it possible to provide light-emitting devices, electronic equipment, or lighting devices with low power consumption.

[0129] The structures of other light-emitting devices can be found in the descriptions of embodiments and examples below. In other words, this embodiment can be used in arbitrary combination with other embodiments and examples.

[0130] (Embodiment 2) This embodiment describes an organic compound that is one aspect of the present invention.

[0131] <Examples of Organic Compounds> <Example 1 of Organic Compounds> One aspect of the present invention is an organic compound represented by the general formula (G2).

[0132]

[0133] However, in the general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Also, R １ ~R ７ And R １１ ~R １７ At least one of the following, and R ２１ ~R ２７ At least one of them is deuterium, R ２８ ~R ３２ At least one of them is light hydrogen.

[0134] Alternatively, in the general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Also, R １ ~R ７ And R １１ ~R １７ At least one of the following, and R ２８ ~R ３２ At least one of them is deuterium, R ２１ ~R ２７ At least one of them is light hydrogen.

[0135] Alternatively, in the general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Also, R １ ~R ７ And R ２１ ~R ２７ At least one of them is deuterium, R １１ ~R １７ At least one of the following and R ２８ ~R ３２At least one of them is light hydrogen.

[0136] Furthermore, in the general formula (G2), R ｍ Specific examples of substituents represented by (where m is any natural number) are shown below.

[0137] Examples of linear or branched alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, neohexyl group, 3-methylpentyl group, 2-methylpentyl group, 2-ethylbutyl group, 1,2-dimethylbutyl group, 2,3-dimethylbutyl group, octyl group, isooctyl group, sec-octyl group, tert-octyl group, nonyl group, isononyl group, sec-nonyl group, tert-nonyl group, decanyl group, isodecanyl group, sec-decanyl group, tert-decanyl group, and the like.

[0138] Examples of cycloalkyl groups include cyclopropyl, cyclohexyl, norbornyl, decahydronaphthyl, and adamantyl groups.

[0139] <Specific Examples> Next, specific examples of organic compounds that have the configuration represented by the above general formula (G2) and are one aspect of the present invention are shown below.

[0140]

[0141] The organic compounds represented by structural formulas (101) to (106) above are examples of organic compounds represented by any of the above general formulas (G2), but the organic compounds of one aspect of the present invention are not limited thereto.

[0142] Furthermore, the deuteration rate of each deuterium in the organic compounds shown in structural formulas (100) to (106) above is preferably 80% or more, but it does not have to be less than 100%.

[0143] For example, using deuterized organic compounds as materials for light-emitting devices can extend the operating life of these devices. Therefore, by using deuterized organic compounds, it is possible to provide light-emitting devices with long operating lives, which contributes to providing highly reliable electronic equipment and lowering device costs for consumers. In addition, deuterized light-emitting materials generally tend to have improved luminous efficiency, making it possible to provide light-emitting devices, electronic equipment, or lighting devices with low power consumption.

[0144] <Method for synthesizing organic compounds> A method for synthesizing organic compounds according to one aspect of the present invention will be described below using the synthesis scheme shown.

[0145] Here, we will explain the synthesis method for the organic compound represented by the following general formula (G2). This synthesis example is R １ ~R ３２ Other organic compounds according to one aspect of the present invention having various substituents can also be synthesized by the same method by using a starting material having substituents corresponding to the relevant substitution positions.

[0146]

[0147] Note that substituent R in the above general formula (G2) and synthesis schemes (S-1) to (S-9) １ ~R ７ , substituent R １１ ~R １７ , substituent R ２１ ~R ２７ , substituent R ２８ ~R ３２ For further information, please refer to the description provided in Embodiment 1 and this embodiment.

[0148] Various reactions can be applied to synthesize the organic compound represented by general formula (G2). For example, the organic compound represented by general formula (G2) can be synthesized by carrying out the synthesis reaction shown below.

[0149] <<Method for synthesizing the organic compound represented by general formula (G2)>> The organic compound represented by general formula (G2) of the present invention can be synthesized by the following synthesis schemes (S-1) to (S-9).

[0150] First, let's explain the synthesis scheme (S-1). Specifically, a carbazole compound (compound 3) can be obtained by coupling a naphthalene compound (compound 1) with a carbazole compound (compound 2). The synthesis scheme (S-1) is shown below.

[0151]

[0152] Next, the synthesis scheme (S-2) will be explained. Specifically, a carbazole compound (compound 4) can be obtained by performing a functional group introduction reaction on the carbazole compound (compound 3). The synthesis scheme (S-2) is shown below.

[0153]

[0154] First, let's explain the synthesis scheme (S-3). Specifically, a carbazole compound (compound 7) can be obtained by coupling a benzene compound (compound 5) with a carbazole compound (compound 6). The synthesis scheme (S-3) is shown below.

[0155]

[0156] Next, the synthesis scheme (S-4) will be explained. Specifically, a carbazole compound (compound 8) can be obtained by performing a functional group introduction reaction on the carbazole compound (compound 7). The synthesis scheme (S-4) is shown below.

[0157]

[0158] Next, the synthesis scheme (S-5) will be described. Specifically, the target compound (G2) can be obtained by coupling a carbazole compound (compound 4) with a carbazole compound (compound 8). The synthesis scheme (S-5) is shown below.

[0159]

[0160] Also, the target compound (G2) can be synthesized by a method using the bicarbolazole compound (Compound 9) as a starting material. Hereinafter, Synthesis Scheme (S-6) and Synthesis Scheme (S-7) will be described.

[0161] First, Synthesis Scheme (S-6) will be described. That is, the bicarbolazole compound (Compound 10) can be obtained by coupling the naphthalene compound (Compound 1) and the bicarbolazole compound (Compound 9). The Synthesis Scheme (S-6) is shown below.

[0162]

[0163] Next, Synthesis Scheme (S-7) will be described. That is, the target compound (G2) can be obtained by coupling the benzene compound (Compound 5) and the bicarbolazole compound (Compound 10). The Synthesis Scheme (S-7) is shown below.

[0164]

[0165] Also, the synthesis method of the target compound (G2) using the bicarbolazole compound (Compound 9) and the benzene compound (Compound 5) first will be described. Hereinafter, Synthesis Scheme (S-8) and Synthesis Scheme (S-9) will be described.

[0166] First, Synthesis Scheme (S-8) will be described. That is, the bicarbolazole compound (Compound 11) can be obtained by coupling the benzene compound (Compound 5) and the bicarbolazole compound (Compound 9). The Synthesis Scheme (S-8) is shown below.

[0167]

[0168] Next, Synthesis Scheme (S-9) will be described. That is, the target compound (G2) can be obtained by coupling the naphthalene compound (Compound 1) and the bicarbolazole compound (Compound 11). The Synthesis Scheme (S-9) is shown below.

[0169]

[0170] In the above reaction synthesis scheme (S-1) to synthesis scheme (S-9), X １ ~X ４ Each of these independently represents hydrogen, halogen, boronic acid group, organoboron group, triflate group, organotin group, organozinc group, amino group, magnesium halide group, etc.

[0171] The halogen is preferably chlorine, bromine, or iodine, more preferably bromine or iodine considering reactivity, and more preferably chlorine or bromine considering cost.

[0172] In synthesis schemes (S-1), (S-3), and (S-6) to (S-9), when carrying out the Buchwald-Hartwig reaction using a palladium catalyst, bis(dibenzylideneacetone)palladium(0), palladium(II) acetate, [1,1-bis(diphenylphosphino)ferrocene]palladium(II) dichloride, tetrakis(triphenylphosphine)palladium(0), allylpalladium(II) chloride (da Palladium compounds such as IMER and ligands such as tri(t-butyl)phosphine, tri(n-hexyl)phosphine, tricyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, tri(ortho-tolyl)phosphine, and di-t-butyl(1-methyl-2,2-diphenylcyclopropyl)phosphine (abbreviated as cBRIDP®) can be used. Phase transfer catalysts such as 18-crown-6-ether can also be used in this reaction. Organic bases such as sodium tert-butoxide, inorganic bases such as potassium carbonate, cesium carbonate, or sodium carbonate can be used in this reaction. Toluene, xylene, benzene, tetrahydrofuran, dioxane, etc. can be used as solvents in this reaction.

[0173] In synthesis schemes (S-1), (S-3), and (S-6) to (S-9), a coupling reaction using copper or a copper compound can be used. Examples of bases used include inorganic bases such as potassium carbonate. Suitable solvents for this reaction include 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU), toluene, xylene, and benzene. In the coupling reaction using copper or a copper compound, a reaction temperature of 100°C or higher allows for faster and higher yield of the target product; therefore, it is preferable to use DMPU or xylene, which have high boiling points. Furthermore, a reaction temperature of 150°C or higher is even more preferable, so DMPU is more preferably used.

[0174] In synthesis schemes (S-2) and (S-4), halogenation reactions can be used as functional group introduction reactions. Examples of such reactions include chloromination, bromination, and iodation reactions.

[0175] In chlorination reactions, N-chlorosuccinimide, oxalyl chloride, and the like can be used as reaction reagents.

[0176] In bromination, N-bromosuccinimide, N-bromophthalimide, bromine, etc., can be used as reaction reagents.

[0177] In iodination, N-iodosuccinimide, N-iodophthalimide, iodine, etc., can be used as reaction reagents.

[0178] In this halogenation reaction, chloroform, dichloroethane, dichloromethane, N,N-dimethylformamide, toluene, xylene, N-methyl-2-pyrrolidone, acetonitrile, acetic acid, ethyl acetate, etc. can be used as solvents.

[0179] Furthermore, in synthesis schemes (S-2) and (S-4), by using functional group introduction reactions, boronic acid groups, organoboron groups, organotin groups, organozinc groups, amino groups, magnesium halide groups, triflate groups, etc., can be introduced into the compounds. In other words, compounds into which functional groups have been introduced by functional group introduction reactions can be used in Suzuki-Miyaura coupling reactions using organoboron compounds, Migita-Kosugi-Still coupling reactions using organotin compounds, Kumada-Tamao-Coliu coupling reactions using Grignard reagents, Negishi coupling reactions using organozinc compounds, and reactions using copper or copper compounds.

[0180] In the synthesis scheme (S-5), when performing the Suzuki-Miyaura coupling reaction using a palladium catalyst, X ２ and X ４ Either one of them represents a boronic acid group, an organoboron group, an organotin group, an organozinc group, an amino group, or a magnesium halide group, X ２ and X ４ The other side represents hydrogen, chlorine, bromine, iodine, or a triflate group, and as the halogen, iodine, bromine, or chlorine is preferred. In this reaction, palladium compounds such as bis(dibenzylideneacetone)palladium(O), palladium(II) acetate, [1,1-bis(diphenylphosphino)ferrocene]palladium(II) dichloride, and tetrakis(triphenylphosphine)palladium(O) can be used, along with ligands such as tri(t-butyl)phosphine, tri(n-hexyl)phosphine, tricyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, and tri(ortho-tolyl)phosphine. In this reaction, organic bases such as sodium t-butoxide, inorganic bases such as potassium carbonate, cesium carbonate, or sodium carbonate can be used.

[0181] In this reaction, toluene, xylene, benzene, tetrahydrofuran, dioxane, ethanol, methanol, water, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether, etc., can be used as solvents. However, the reagents that can be used in this reaction are not limited to these.

[0182] The reaction represented by the synthesis scheme (S-5) can be carried out using the Migita-Kosugi-Still coupling reaction with organotin compounds, the Kumada-Tamao-Coliu coupling reaction with Grignard reagents, the Negishi coupling reaction with organozinc compounds, or reactions using copper or copper compounds.

[0183] Furthermore, the method for synthesizing the organic compound (G2) of the present invention is not limited to synthesis schemes (S-1) to (S-9).

[0184] This embodiment can be used in any combination with other embodiments and examples.

[0185] (Embodiment 3) This embodiment describes the configuration of the light-emitting device of the present invention.

[0186] Organic EL displays, which use organic EL devices (hereinafter also called light-emitting devices) as display devices, have been in practical use for quite some time. These displays typically have pixels that emit at least three colors of light: red, green, and blue, in order to achieve full-color display.

[0187] Each pixel is provided with a light-emitting device for each emission color, and in a side-by-side display, also known as a color-coded display, each light-emitting device has a different light-emitting material according to the emission color of the corresponding pixel.

[0188] In particular, the deuterium-containing organic compounds described in Embodiment 1 or Embodiment 2 can be suitably used as host materials. Therefore, one aspect of the present invention is a light-emitting device using the organic compound described in Embodiment 2 as the host material.

[0189] Furthermore, the organic compounds described in Embodiment 2 can be used not only in the hole transport layer and the light-emitting layer, but also, for example, in the cap layer. They can be used appropriately in the design of organic EL devices depending on the desired characteristics.

[0190] <Basic Structure of Light-Emitting Devices> Below, the basic structure of light-emitting devices will be explained in more detail using Figures 5A to 5E. Figure 5A shows a light-emitting device with a structure (single structure) having an organic compound layer (also called an EL layer) containing a light-emitting layer between a pair of electrodes. Specifically, it has a structure in which an organic compound layer 103 is sandwiched between a first electrode 101 and a second electrode 102.

[0191] Furthermore, Figure 5B shows a light-emitting device with a laminated structure (tandem structure) having multiple (two layers in Figure 5B) organic compound layers (103a, 103b) between a pair of electrodes, and a charge generation layer 106 between the organic compound layers. A light-emitting device with a tandem structure can realize a highly efficient light-emitting device without changing the amount of current.

[0192] The charge generation layer 106 has the function of injecting electrons into one organic compound layer (103a or 103b) and holes into the other organic compound layer (103b or 103a) when a potential difference is created between the first electrode 101 and the second electrode 102. Therefore, in Figure 5B, when a voltage is applied to the first electrode 101 such that its potential 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.

[0193] Furthermore, from the viewpoint of light extraction efficiency, it is preferable that the charge generation layer 106 is transparent to visible light (specifically, the transmittance of visible light to the charge generation layer 106 is 40% or more). In addition, the charge generation layer 106 can function even if its conductivity is lower than that of the first electrode 101 and the second electrode 102.

[0194] Figure 5C also shows the laminated structure of the 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 laminated on the first electrode 101. The light-emitting layer 113 may be configured by laminating multiple light-emitting layers with different emission 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 laminated, or laminated via a layer having a carrier transport material. Alternatively, a combination of a light-emitting layer containing a yellow light-emitting substance and a light-emitting layer containing a blue light-emitting substance may be used. However, the laminated structure of the light-emitting layer 113 is not limited to the above. For example, the light-emitting layer 113 may be configured by stacking multiple light-emitting layers of the same emission color. For example, it may be a structure in which 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 stacked via a layer having a carrier transport material. In the case of a configuration in which multiple light-emitting layers of the same emission color are stacked, reliability can be increased compared to a single-layer configuration. Also, even when there are multiple light-emitting layers as in the tandem structure shown in Figure 5B, each light-emitting layer is stacked sequentially from the anode side as described above. Furthermore, when the first electrode 101 is the cathode and the second electrode 102 is the anode, the stacking order of the organic compound layer 103 is reversed. Specifically, on the first electrode 101 which is the cathode, 111 is an electron injection layer, 112 is an electron transport layer, 113 is a light-emitting layer, 114 is a hole transport layer, and 115 is a hole injection layer.

[0195] The light-emitting layer 113 included in the organic compound layers (103, 103a, 103b) has a light-emitting substance and a plurality of substances appropriately combined, and can be configured to obtain fluorescence emission or phosphorescence emission presenting a desired emission color. Also, the light-emitting layer 113 may have a stacked structure with different emission colors. In this case, different materials may be used for the light-emitting substance and other substances used in each stacked light-emitting layer. Also, a configuration may be adopted in which different emission colors can be obtained from the plurality of organic compound layers (103a, 103b) shown in FIG. 5B. In this case as well, different materials may be used for the light-emitting substance and other substances used in each light-emitting layer.

[0196] Further, in the light-emitting device which is one aspect of the present invention, for example, by making the first electrode 101 shown in FIG. 5C a reflective electrode, the second electrode 102 a semi-transmissive / semi-reflective electrode, and adopting a microcavity structure, the light emission obtained from the light-emitting layer 113 included in the organic compound layer 103 can be resonated between both electrodes, and the light emission emitted from the second electrode 102 can be enhanced. Therefore, it is easy to achieve high definition. Also, since it becomes possible to enhance the emission intensity in the front direction of a specific wavelength, power consumption can be reduced.

[0197] When the first electrode 101 of the light-emitting device is a reflective electrode having a laminated structure of a conductive material having reflectivity and a conductive material having translucency (transparent conductive film), optical adjustment can be performed by controlling the film thickness of the transparent conductive film. Specifically, it is preferable to adjust so that the optical distance (the product of the film thickness and the refractive index) between the first electrode 101 and the second electrode 102 becomes mλ / 2 (where m is an integer of 1 or more) or in the vicinity thereof with respect to the wavelength λ of the light obtained from the light-emitting layer 113.

[0198] 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 of the light-emitting layer 113 from which the desired light is obtained (light-emitting region), and the optical distance from the second electrode 102 to the region of the light-emitting layer 113 from which the desired light is obtained (light-emitting region), so that they are (2m'+1)λ / 4 (where m' is an integer of 1 or more) or near that value. The light-emitting region referred to here is the region in the light-emitting layer 113 where holes and electrons recombine.

[0199] By performing such optical adjustments, the spectrum of specific monochromatic light obtained from the light-emitting layer 113 can be narrowed, resulting in light emission with good color purity.

[0200] However, in the above case, the optical distance between the first electrode 101 and the second electrode 102 can be precisely 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 effects can be sufficiently obtained by assuming that any position on the first electrode 101 and the second electrode 102 is the reflective region. Furthermore, the optical distance between the first electrode 101 and the light-emitting layer from which the desired light is obtained can be precisely 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 the 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 the desired light is obtained, the above effects can be sufficiently obtained by assuming that any position on the first electrode 101 is the reflective region and any position on the light-emitting layer from which the desired light is obtained is the light-emitting region.

[0201] The light-emitting device shown in Figure 5D is a light-emitting device having a tandem structure. The tandem structure allows for a light-emitting device capable of high-brightness illumination. Furthermore, compared to a single structure, the tandem structure reduces the current required to achieve the same brightness, thereby improving reliability. It also reduces power consumption.

[0202] The light-emitting device shown in Figure 5E is an example of a tandem-structured light-emitting device shown in Figure 5B. As shown in the figure, it has a structure in which three organic compound layers (103a, 103b, 103c) are stacked with charge generation layers (106a, 106b) in between. Each of the three organic compound layers (103a, 103b, 103c) has a light-emitting layer (113a, 113b, 113c), and the light-emitting colors of each light-emitting layer can be freely combined. For example, light-emitting layer 113a can be blue, light-emitting layer 113b can be red, green, or yellow, and light-emitting layer 113c can be blue. Alternatively, light-emitting layer 113a can be red, light-emitting layer 113b can be blue, green, or yellow, and light-emitting layer 113c can be red.

[0203] In the light-emitting device according to one aspect of the present invention described above, at least one of the first electrode 101 and the second electrode 102 is a light-transmitting electrode (such as a transparent electrode or a semi-transparent / 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 it is a semi-transparent / semi-reflective electrode, the visible light reflectance of the semi-transparent / 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 × 10⁻¹⁶. −２ It is preferable to keep it below Ωcm.

[0204] Furthermore, in the light-emitting device according to one aspect of the present invention described above, if one of the first electrode 101 and the second electrode 102 is a reflective electrode (reflective electrode), the visible light reflectance of the reflective electrode is 40% or more and 100% or less, preferably 70% or more and 100% or less. Also, the resistivity of this electrode is 1 × 10⁻¹⁶. −２ It is preferable to keep it below Ωcm.

[0205] <Specific Structure of the Light-Emitting Device> Next, a specific structure of a light-emitting device according to one aspect of the present invention will be described. Here, the explanation will be given using Figure 5D, which has a tandem structure. The same applies to the configuration of the organic compound layer for the single-structure light-emitting devices shown in Figures 5A and 5C. Furthermore, if the light-emitting device shown in Figure 5D has a microcavity structure, the first electrode 101 is formed as a reflective electrode, and the second electrode 102 is formed as a semi-transparent / semi-reflective electrode. Thus, one or more desired electrode materials can be used and formed in a single layer or in a stacked manner. The second electrode 102 is formed by selecting an appropriate material after the organic compound layer 103b has been formed.

[0206] <Materials for Light-Emitting Devices> <Light-Emitting Layers> The light-emitting layers (113, 113a, 113b) are layers containing a light-emitting material. The light-emitting material that can be used in the light-emitting layers (113, 113a, 113b) can be any material that exhibits a light-emitting color such as blue, purple, blue-violet, green, yellow-green, yellow, orange, or red. Furthermore, if there are multiple light-emitting layers, a configuration exhibiting different light-emitting colors can be achieved by using different light-emitting materials in each layer (for example, white light emission obtained by combining complementary light-emitting colors). Additionally, a laminated structure in which one light-emitting layer contains a different light-emitting material is also possible.

[0207] Furthermore, the light-emitting layers (113, 113a, 113b) may contain one or more types of organic compounds (host materials, etc.) in addition to the light-emitting substance (guest material).

[0208] Specifically, the structure described with reference to Figure 1B can be used as the light-emitting layer 113. In the light-emitting layer 113, the host material 118 is present in the largest amount by weight, and the guest material 119 (phosphorescent compound) is dispersed in the host material 118. The T of the host material 118 (organic compound 118_1 and organic compound 118_2) of the light-emitting layer 113 １ The energy level is the T of the guest material (guest material 119) of the light-emitting layer 113. １ It is preferable that the level be higher than the current level.

[0209] Furthermore, as mentioned above, the host material 118 can also be an organic compound represented by general formula (G1) to general formula (G3) as described in Embodiment 1, or in particular, an organic compound represented by general formula (G2) as described in Embodiment 2.

[0210] Lowest triplet excitation energy level (T １ The lowest triplet excitation energy level (T) can be calculated from the emission edge obtained by measuring the emission spectrum (phosphorescence spectrum) at a low measurement temperature (e.g., 10 K) using a thin film on which the sample has been deposited. The sample form when measuring the emission spectrum of the emission center material may be a thin film or a solution, but a solution is preferred from the viewpoint of verifying the state of isolated molecules. As the solvent for the solution, a solvent with relatively low polarity such as toluene or chloroform is preferred. Furthermore, if the emission center material is a phosphorescent compound, the lowest triplet excitation energy level (T) can be calculated. １ The temperature at which the energy level is measured can be low (e.g., 10 K) or room temperature (e.g., 298 K), and it can be calculated from the emission edge obtained by measuring the emission spectrum (phosphorescence spectrum). The emission edge can be calculated by drawing a tangent line at the point where the slope on the short-wavelength side of the peak (or shoulder peak) observed at the shortest wavelength of the emission spectrum (phosphorescence spectrum) is maximum, and then finding the intersection of that tangent line with the horizontal axis (wavelength) or baseline.

[0211] <<Luminescent material that converts triplet excitation energy into light>> Next, as luminescent materials that can be used in the light-emitting layer 113 to convert triplet excitation energy into light, examples include phosphorescent materials (phosphorescent materials) or thermally activated delayed fluorescence (TADF) materials that exhibit thermally activated delayed fluorescence.

[0212] A phosphorescent material is a compound that exhibits phosphorescence and does not fluoresce at any temperature range from low temperature (e.g., 77 K) to room temperature (i.e., 77 K to 313 K). The phosphorescent material preferably contains a metal element with strong spin-orbit interaction, and examples include organometallic complexes, metal complexes (platinum complexes), and rare earth metal complexes. Specifically, transition metal elements are preferred, and particularly platinum group elements (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), or platinum (Pt)) are preferred. The presence of iridium is especially preferable because it increases the transition probability involved in the direct transition between the singlet ground state and the triplet excited state.

[0213] Examples of luminescent materials that can be used as guest materials include substances that exhibit red emission. Furthermore, among the substances that exhibit red emission, phosphorescent substances, particularly organometallic complexes, are more preferable. Examples of such luminescent materials include (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(III) (abbreviation: [Ir(5mdppm)]). ２ (dibm)]), bis[4,6-bis(3-methylphenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(5mdppm) ２ (dpm)]), bis[4,6-di(naphthalene-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm) ２ Organometallic iridium complexes having a pyrimidine skeleton such as (dpm)]), (acetylacetonato)bis(2,3,5-triphenylpyradinato)iridium(III) (abbreviation: [Ir(tppr) ２ (acac)), bis(2,3,5-triphenylpyrazinate)(dipivaloylmethanato) iridium(III) (abbreviation: [Ir(tppr) ２ (dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq) ２Organometallic iridium complexes having a pyrazine skeleton such as (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)), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[7-(1-methylethyl)-1-isoquinolinyl-κN]phenyl-κC]iridium(III), (3,7-diethyl-4,6-nonanedionato-κO4,κO6)bis[2,4-dimethyl-6-[5-(1-methylethyl)-2-quinolinyl-κN]phenyl In addition to organometallic iridium complexes with a pyridine skeleton such as [-κC]iridium(III), there are platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP), and tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM)] ３ (Phen)]), Tris[1-(2-tenoyl)-3,3,3-trifluoroacetonate](monophenanthroline) europium(III) (abbreviation: [Eu(TTA) ３ Examples include rare earth metal complexes such as (Phen)). These exhibit emission peaks in the wavelength range of 600 nm to 700 nm. Furthermore, organometallic iridium complexes with a pyrazine skeleton yield red emission with good chromaticity. Other known substances that exhibit red phosphorescence can also be used.

[0214] When a phosphorescent material is used as the light-emitting material in the light-emitting layer 113, possible materials that can be used include, for example, the following:

[0215] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazole-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 ]) an organometallic iridium complex having a 4H-triazole skeleton, such as tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazolato]iridium(III) (abbreviation: [Ir(Mptz1-mp) ３ ]), Tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato) Iridium(III) (abbreviation: [Ir(Prptz1-Me) ３ ]) an organometallic iridium complex having a 1H-triazole skeleton, such as 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]phenanthridine]iridium(III) (abbreviation: [Ir(dmpimpt-Me) ３ ]), organometallic iridium complexes having an imidazole skeleton such as tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazole-2-yl-κN3}-4-cyanophenyl-κC) (abbreviation: CNImIr), tris[(6-tert-butyl-3-phenyl-2H-imidazol[4,5-b]pyrazine-1-yl-κC2)phenyl-κC]iridium(III) (abbreviation: [Ir(cb) ３ ]) an organoiridium metal complex having a benzimidazolidene skeleton, bis[2-(4',6'-difluorophenyl)pyridinato-N,C ２’ Iridium(III) tetrakis(1-pyrazolyl) borate (abbreviation: FIr6), bis[2-(4',6'-difluorophenyl)pyridinate-N,C ２’ Iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinate-N,C ２’ Iridium (III) picolinate (abbreviation: [Ir(CF ３ ppy) ２(pic)]), bis[2-(4',6'-difluorophenyl)pyridinate-N,C ２’ Examples include organometallic iridium complexes that use phenylpyridine derivatives having electron-withdrawing groups, such as iridium(III) acetylacetonate (abbreviated as FIr(acac)), as ligands. These compounds exhibit blue phosphorescence and have emission peaks in the wavelength range from 440 nm to 520 nm.

[0216] Also, tris(4-methyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ３ ]), Tris(4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ３ ]), (acetylacetonato)bis(6-methyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(mppm) ２ (acac)), (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviation: [Ir(tBuppm) ２ (acac)), (acetylacetonate)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(mpmpppm) ２ (acac)), (acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm) ２ Organometallic iridium complexes having a pyrimidine skeleton such as (acac) (acetylacetonato)bis(3,5-dimethyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-Me) ２ (acac)), (acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyradinato)iridium(III) (abbreviation: [Ir(mppr-iPr) ２Organometallic iridium complexes having a pyrazine skeleton such as (acac), Tris(2-phenylpyridinato-N,C) ２’ Iridium (III) (abbreviation: [Ir(ppy) ３ ]), bis(2-phenylpyridinate-N,C ２’ ) Iridium(III) acetylacetonate (abbreviation: [Ir(ppy) ２ (acac)), bis(benzo[h]quinolinate)iridium(III)acetylacetonate (abbreviation: [Ir(bzq) ２ (acac)), Tris(benzo[h]quinolinate) Iridium(III) (abbreviation: [Ir(bzq) ３ ]), Tris(2-phenylquinolinato-N,C) ２’ Iridium (III) (abbreviation: [Ir(pq) ３ ]), bis(2-phenylquinolinato-N,C ２’ Iridium(III) acetylacetonate (abbreviation: [Ir(pq) ２ (acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofl[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]benzofl[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d3)-2-[5-(methyl-d3)-2-pyridinyl-κN]phenyl-κC}Iridium(III) (abbreviation: Ir(5mtpy-d6) ２ (mbfpypy-iPr-d4)), [2-d3-methyl-(2-pyridinyl-κN)benzofl[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ (mbfpypy-d3)), [2-(4-d3-methyl-5-phenyl-2-pyridinyl-κN2)phenyl-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3) ２(mdppy-d3)]), [2-methyl-(2-pyridinyl-κN)benzofl[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) ２ (mbfpypy))]), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: Ir(ppy) ２ In addition to organometallic iridium complexes with a pyridine skeleton such as (mdppy), there is also tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac) ３ Examples include rare earth metal complexes such as (Phen)). These are compounds that mainly exhibit green phosphorescence and have emission peaks in the wavelength range of 500 nm to 600 nm. Organometallic iridium complexes with a pyrimidine skeleton are particularly preferred because they exhibit outstanding reliability and luminescence efficiency.

[0217] In addition to the phosphorescent compounds described above, other known phosphorescent compounds may be selected and used.

[0218] <<Luminescent material that converts singlet excitation energy into light emission>> Examples of materials that can be used as luminescent materials that exhibit fluorescence emission in the light-emitting layer 113 include the following. Other fluorescent luminescent materials can also be used.

[0219] 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazabolino[2,3,4-kl]phenazabolin-7-amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzazabolino[2,3,4-kl]phenazabolin-7-amine (abbreviation: tBuDPhA-tBu4DABNA), N,N,5,9-tetraphenyl-5H,9H-[1,4] Benzazaborino[2,3,4-kl]phenazavolin-7-amine (abbreviation: DPhA-DABNA), 7-(9H-carbazole-9-yl)-5,9-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazavolin (abbreviation: Cz-DABNA), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazavolin (abbreviation: Me-tBu4DABNA), 3,11-bis(2,7-di-tert-butyl-9 H-carbazole-9-yl)-7-[2,7-di(3,5-di-tert-butylphenyl)-9H-carbazole-9-yl]-5,9-diphenyl-5H,9H-[1,4]benzazabolino[2,3,4-kl]phenazabolin (abbreviation: mmtBuP2Cz-(2,7tBuCz)2DABNA), N7,N7,N13,N13,5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzazabolino[2,3,4-kl][1,4]benzazabolino[4',3',2':4,5][1,4]benzazabolino[ 3,2-b]phenazavolin-7,13-diamine (abbreviation: ν-DABNA), 5,9-diphenyl-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (abbreviation: DABNA-1), N-(biphenyl-3-yl)-N,5,9-tris(2,6-dimethylphenyl)-3,11-diphenyl-5,9-dihydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene-7-amine (abbreviation: mBP-DABNA-Me), N-(biphenyl-4-yl)-N,5,9-tris(2,6-dimethylphenyl)-2,12-diphenyl-5,9-dihydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene-7-amine (abbreviation: pBP-DABNA-Me), 2,12-di-tert-butyl-5,9-bis[4-(tert-butyl)phenyl]-7(3,6-di-tert-butyl-9H-carbazole-9-yl)-5,9-dihydro-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (abbreviation: TBN-TPA), N7,N7,N13,N13,5,15-hexaphenyl-9 Examples include 11-bis[4-(tert-butyl)phenyl]-5,9,11,15-tetrahydro-5,9,11,15-tetraaza-19b,20b-diborazinaphth[3,2,1-de:1',2',3'-jk]pentacene-7,13-diamine (abbreviation: t-Bu-ν-DABNA) and 2,12-di-tert-butyl-5,9-bis[4-(tert-butyl)phenyl]-5,9-dihydro-5,9-diaza-13b-boranaphth[3,2,1-de]anthracene (abbreviation: t-DABNA).

[0220] 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2,2'-bipyridine (abbreviation: PAPP2BPy), 5,6-bis[4'-(10-phenyl-9-antryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyren-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl] )phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAAPPA), N,9-diphenyl-N-[4-( 10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis(N,N',N'-triphenyl-1,4-phenylenediamine) (abbreviation: DPABPA), N,9 -Diphenyl-N-[4-(9,10-diphenyl-2-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N'',N''',N'''-octaphenyldibenzo[g,p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9,10-diphenyl-2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazole-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-carbazole-9-yl)phenyl]-N-phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracene-9-amine (abbreviation: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (abbreviation: DPQd), rubren, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyra N-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-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]fluorantene-3,10-diamine (abbreviation) Name: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-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]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2,6-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]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N'-diphenyl-N,N'-(1,6-pyrene-diyl)bis[(6-phenylbenzo[b]naph Examples include to[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), N,N'-diphenyl-N,N'-bis(9-phenyl-9H-carbazole-2-yl)naphtho[2,3-b;6,7-b']bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), and 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b']bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02). In particular, condensed aromatic diamine compounds, such as pyrenediamine compounds like 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPPrn-03, are preferred because they exhibit high hole-trapping properties and excellent luminescence efficiency or reliability.

[0221] <<Luminescent material that converts triplet excitation energy into light>> Another luminescent material that can be used in the light-emitting layer 113 and converts triplet excitation energy into light is TADF material.

[0222] As TADF materials, fullerenes and their derivatives, acridines and their derivatives, eosin derivatives, etc. can be used. Also, metal-containing porphyrins containing magnesium (Mg), zinc (Zn), cadmium (Cd), tin (Sn), platinum (Pt), indium (In), or palladium (Pd) can be used. As an example of such metal-containing porphyrins, protoporphyrin-tin fluoride complex (SnF) shown in the following structural formula can be used. ２ (Proto IX)), Mesoporphyrin-Tin Fluoride Complex (SnF ２ (Meso IX), hematoporphyrin-tin fluoride complex (SnF ２(Hemato IX), coproporphyrin tetramethyl ester-tin fluoride complex (SnF ２ (Copro III-4Me)), Octaethylporphyrin-Tin Fluoride Complex (SnF ２ (OEP)), Ethioporphyrin-Tin Fluoride Complex (SnF ２ (Etio I)), Octaethylporphyrin-Platinum Chloride Complex (PtCl ２ OEP (Open Economic Programme) and others can also be mentioned.

[0223]

[0224] Furthermore, the following structural formulas represent 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTZn), 9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: PCCzPTZn), and 2-[4-(10H-phenoxazine-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ). Heterocyclic compounds having one or both of a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring can also be used, such as -TRZ), 3-[4-(5-phenyl-5,10-dihydrophenadin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviated as PPZ-3TPT), 3-(9,9-dimethyl-9H-acridine-10-yl)-9H-xanthene-9-one (abbreviated as ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviated as DMAC-DPS), and 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviated as ACRSA). The heterocyclic compound is preferred because it has both a π-electron-excess heteroaromatic ring and a π-electron-deficient heteroaromatic ring, resulting in high electron transport and hole transport properties. Among the skeletons having a π-electron-deficient heteroaromatic ring, the pyridine skeleton, diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and triazine skeleton are preferred because they are stable and reliable. In particular, the benzoflopyrimidine skeleton, benzothienopyrimidine skeleton, benzoflopyrazine skeleton, and benzothienopyrazine skeleton are preferred because they have high acceptability and are reliable. Furthermore, among the skeletons having a π-electron-excess heteroaromatic ring, the acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton are preferred because they are stable and reliable, and therefore it is preferable to have at least one of these skeletons. Dibenzofuran skeleton is preferred as the furan skeleton, and dibenzothiophene skeleton is preferred as the thiophene skeleton.Furthermore, as pyrrole skeletons, indole skeletons, carbazole skeletons, indrocarbazole skeletons, bicarbazole skeletons, and 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeletons are particularly preferred. In addition, in substances in which a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded, both the electron-donating ability of the π-electron-rich heteroaromatic ring and the electron-accepting ability of the π-electron-deficient heteroaromatic ring are strengthened. １ Level and T １ This is particularly preferable because the energy difference between the energy levels becomes small, allowing for efficient acquisition of thermally activated delayed fluorescence. Alternatively, an aromatic ring to which an electron-withdrawing group such as a cyano group is attached may be used instead of the π-electron-deficient heteroaromatic ring. Furthermore, aromatic amine skeletons, phenazine skeletons, etc., can be used as the π-electron-rich skeleton. Additionally, boron-containing skeletons such as xanthene skeletons, thioxanthene dioxide skeletons, oxadiazole skeletons, triazole skeletons, imidazole skeletons, anthraquinone skeletons, boron-containing skeletons such as phenylborane or volanthrene, aromatic rings or heteroaromatic rings having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, carbonyl skeletons such as benzophenone, phosphine oxide skeletons, sulfone skeletons, etc. Thus, a π-electron-deficient skeleton and a π-electron-rich skeleton can be used instead of at least one of the π-electron-deficient heteroaromatic ring and the π-electron-rich heteroaromatic ring.

[0225]

[0226] Furthermore, a TADF material may be used that enables extremely fast and reversible intersystem crossing, and in which the singlet and triplet excited states emit light according to a thermal equilibrium model. Such a TADF material has an extremely short emission lifetime (excitation lifetime) as a TADF material, and can suppress efficiency degradation in the high-brightness region of light-emitting devices. Specifically, materials with the molecular structure shown below are examples.

[0227]

[0228] Note that TADF material is S １ Level and T １This material has a small energy level difference and possesses the ability to convert energy from triplet excitation energy to singlet excitation energy through reverse intersystem crossing. Therefore, triplet excitation energy can be upconverted to singlet excitation energy with only a small amount of thermal energy (reverse intersystem crossing), and singlet excited states can be efficiently generated. Furthermore, triplet excitation energy can be converted into luminescence.

[0229] Furthermore, an excited complex (also called an exciplex) that forms an excited state with two types of substances is S １ Level and T １ It has an extremely small difference from the energy level and functions as a TADF material capable of converting triplet excitation energy into singlet excitation energy.

[0230] Furthermore, as an indicator of the T1 level, the phosphorescence spectrum observed at low temperatures (for example, from 77K to 10K) can be used. For TADF materials, a tangent line is drawn at the short-wavelength tail of its fluorescence spectrum, and the energy of the extrapolation line wavelength is S. １ Set the energy level as T, draw a tangent line at the short-wavelength tail of the phosphorescence spectrum, and define the energy of the extrapolation line at the wavelength as T. １ When it is set as a level, that S １ and T １ The difference is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0231] Furthermore, when using TADF material as a light-emitting material, the S of the host material １ The level is S of the TADF material. １ A higher level is preferable. Also, the T of the host material １ The level is T of the TADF material. １ A level higher than the current level is preferable.

[0232] Examples of electron transport materials used in the host material (corresponding to the first organic compound in one embodiment of the present invention) include bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviated as BeBq). ２Metal complexes such as bis(2-methyl-8-quinolinolato)(4-phenylphenololato)aluminum(III) (abbreviated as BAlq), bis(8-quinolinolato)zinc(II) (abbreviated as Znq), bis[2-(2-benzoxazollyl)phenololato]zinc(II) (abbreviated as ZnPBO), and bis[2-(2-benzothiazolyl)phenololato]zinc(II) (abbreviated as ZnBTZ), as well as organic compounds having a π-electron-deficient heteroaromatic ring, can be used. Examples of organic compounds having a π-electron-deficient heteroaromatic ring include 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), and 1,3-bis[5-(4-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as Azole skeletons such as OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), and 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II) Organic compounds containing heteroaromatic rings, such as 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPBQ-II), and 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2m CzBPDBq), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 2,4-bis[4-(1-naphthyl)phenyl]-6-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 6-(biphenyl-3-yl)-4-[3,Organic compounds containing heteroaromatic rings with a diazine skeleton, such as 5-bis(9H-carbazole-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), and 7-[4-(9-phenyl-9H-carbazole-2-yl)quinazoline-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), and 3,5-bis[3-(9 Organic compounds containing heteroaromatic rings with a pyridine skeleton, such as H-carbazole-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[(3-pyridyl)phenyl-3-yl]benzene (abbreviation: TmPyPB), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTZn), 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobio[9H-fluoren]-2-yl)-1,3,5-triazine Zin (abbreviation: BP-SFTZn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTZn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTZn-02), 5-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2, 1-b]carbazole (abbreviation: mINc(II)PTZn), 2-[3'-(triphenylene-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTZn), 3-[9-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTZn), 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',1''-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,Examples include organic compounds containing heteroaromatic rings having a triazine skeleton, such as 5-triazine (abbreviated as mBP-TPDBfTZn). Among those mentioned above, organic compounds containing heteroaromatic rings having a diazine skeleton, organic compounds containing heteroaromatic rings having a pyridine skeleton, and organic compounds containing heteroaromatic rings having a triazine skeleton are preferred due to their good reliability. In particular, organic compounds containing heteroaromatic rings having a diazine (pyrimidine and pyrazine) skeleton and organic compounds containing heteroaromatic rings having a triazine skeleton exhibit high electron transport properties and contribute to reducing the driving voltage.

[0233] As the hole-transporting material used as the host material (corresponding to the second organic compound in one embodiment of the present invention), an organic compound having an amine skeleton or a π-electron-rich heteroaromatic ring can also be used. Examples of such organic compounds having an amine skeleton or a π-electron-rich heteroaromatic ring include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviated as TPD), N,N'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as BSPB), and 4-phenyl-4'- (9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBi1BP), 4-(1-naphthyl) -4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl) Compounds having an aromatic amine skeleton such as [9,9'-spirobi[9H-fluorene]-2-amine (abbreviated as PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviated as PCBiF), 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,Compounds having a carbazole skeleton such as 5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), compounds having a 3,3'-bicarbazole skeleton such as 9,9'-diphenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCP), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (abbreviation: D Examples include compounds having a thiophene skeleton such as BTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), and compounds having a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferred because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. Furthermore, organic compounds listed as examples of hole transportable materials in the hole transport layer 112 can also be used as hole transport materials for the host.

[0234] Furthermore, by mixing electron transport material and hole transport material, the transport properties of the light-emitting layer 113 can be easily adjusted, and the recombination region can be easily controlled. In addition, TADF material can also be used as either an electron transport material or a hole transport material.

[0235] The TADF materials listed above can be used as host materials. When a TADF material is used as a host material, the triplet excitation energy generated by the TADF material is converted into singlet excitation energy through reverse intersystem crossing, and this energy is further transferred to the light-emitting material, thereby increasing the luminescence efficiency of the light-emitting device. In this case, the TADF material functions as an energy donor, and the light-emitting material functions as an energy acceptor.

[0236] This is very effective when the above-mentioned luminescent material is a fluorescent luminescent material. Also, in order to obtain high luminescence efficiency in this case, the S of the TADF material １ The energy level is S of the fluorescent material. １ It is preferable that the level be higher than the level. Also, the T of the TADF material １ The energy level is S of the fluorescent material. １ It is preferable that the level be higher than the level of the TADF material. １ The energy level is the T of the fluorescent material. １ A level higher than the current level is preferable.

[0237] Furthermore, it is preferable to use a TADF material that exhibits emission that overlaps with the wavelength of the lowest-energy absorption band of the fluorescent material. This is preferable because it allows for a smooth transfer of excitation energy from the TADF material to the fluorescent material, resulting in efficient emission.

[0238] Furthermore, for singlet excitation energy to be efficiently generated from triplet excitation energy by reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. It is also preferable that the triplet excitation energy generated in the TADF material does not transfer to the triplet excitation energy of the fluorescent material. To achieve this, it is preferable that the fluorescent material has protecting groups around the luminescent phosphoform (the skeleton that causes luminescence). Preferred protecting groups are substituents without π bonds, saturated hydrocarbons, specifically alkyl groups having 3 to 10 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3 to 10 carbon atoms, and trialkylsilyl groups having 3 to 10 carbon atoms. It is even more preferable to have multiple protecting groups. Substituents without π bonds have poor carrier transport function, and therefore can increase the distance between the TADF material and the luminescent phosphoform of the fluorescent material with little effect on carrier transport and carrier recombination. Here, the luminescent phosphoform refers to the atomic group (skeleton) that causes luminescence in the fluorescent material. The luminescent phosphophore preferably has a skeleton containing π bonds, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of such luminescent phosphophores include phenanthrene skeletons, stilbene skeletons, acridone skeletons, phenoxazine skeletons, phenothiazine skeletons, naphthalene skeletons, anthracene skeletons, fluorene skeletons, chrysene skeletons, triphenylene skeletons, tetracene skeletons, pyrene skeletons, perylene skeletons, coumarin skeletons, quinacridone skeletons, and naphthobisbenzofuran skeletons. Fluorescent materials having naphthalene, anthracene, fluorene, chrysene, triphenylene, tetracene, pyrene, perylene, coumarin, quinacridone, and naphthobisbenzofuran skeletons are particularly preferred due to their high fluorescence quantum yield.

[0239] When using a fluorescent material as a light-emitting substance, a material having an anthracene skeleton is preferred as the host material. Using a material having an anthracene skeleton as the host material for a fluorescent material makes it possible to realize a light-emitting layer with good luminescence efficiency and durability. Among the materials having an anthracene skeleton to be used as a host material, materials having a diphenylanthracene skeleton, a dinaphthylanthracene skeleton, a phenylnaphthylanthracene skeleton, and especially 9,10-diphenylanthracene skeleton, 9,10-dinaphthylanthracene skeleton, and 9-phenyl-10-naphthylanthracene skeleton are preferred because they are chemically stable. Furthermore, while it is preferable for the host material to have a carbazole skeleton because it improves hole injection and transportability, it is even more preferable if the host material contains a benzocarbazole skeleton in which a benzene ring is further condensed into the carbazole skeleton, as this makes the HOMO about 0.1 eV shallower than that of a host material having a carbazole skeleton, making it easier for holes to enter. In particular, when the host material contains a dibenzocarbazole skeleton, the HOMO becomes about 0.1 eV shallower than that of a host material containing only a carbazole skeleton, making it easier for holes to enter, and it is also preferable because it exhibits excellent hole transport properties and high heat resistance. Therefore, a more preferable host material is a substance that simultaneously contains a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton). Furthermore, from the viewpoint of the above-mentioned hole injection and transport properties, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton. Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole (abbreviated as PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviated as PCPN), 9-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole (abbreviated as CzPA), 9-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]-10-phenylanthracene (abbreviated as CzPAP), 7-[4-(10-phenyl-9-antryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviated as cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-[4'-(9-phenyl-9H-fluoren-9-yl)biphenyl-4-yl]anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,βADN), 2-(10-phenylanthracene-9-yl)dibenzofuran, 4-[3-(9,10-diphenyl- 2-Anthryl)phenyl]dibenzofuran (abbreviation: 2mDBFPPA-II), 2-(10-phenyl-9-antryl)benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 9-(1-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: αN-mβNPAnth), 1-{4-[10- (biphenyl-4-yl)-9-anthryl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), 7-(10-phenyl-9-anthryl)benzo[b]naphtho[2,1-d]furan (abbreviation: aBnfPhA), 2-(10-phenyl-9-anthryl)dibenzofuran (abbreviation: DBfPhA), 2-[10-(biphenyl-2-yl)-9-anthryl]benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II) Examples include )oBPhA), 2-[10-(biphenyl-4-yl)-9-anthryl]benzo[b]naphtho[2,3-d]furan (abbreviated as Bnf(II)BPhA), 2-[10-(biphenyl-3-yl)-9-anthryl]benzo[b]naphtho[2,3-d]furan (abbreviated as Bnf(II)mBPhA), and 2-[10-(biphenyl-3-yl)-9-anthryl]benzo[b]naphtho[1,2-d]furan (abbreviated as Bnf(6)mBPhA). In particular, CzPA, CzPAP, cgDBCzPA, 2mBnfPPA, PCzPA, αN-mβNPAnth, and 2αN-αNPAnth exhibit very good properties and are therefore preferred choices.

[0240] Furthermore, phosphorescent materials can be used as part of the above-mentioned mixed materials. When a fluorescent material is used as the light-emitting material, the phosphorescent material can be used as an energy donor to supply excitation energy to the fluorescent material.

[0241] Furthermore, an excitation complex may be formed between the mixed materials described above. It is preferable to select a combination of materials that forms an excitation complex that exhibits emission overlapping with the wavelength of the lowest-energy absorption band of the luminescent material, as this facilitates smooth energy transfer and efficiently obtains light emission. This configuration is also preferable because it reduces the driving voltage.

[0242] Furthermore, at least one of the materials forming the excitation complex may be a phosphorescent material. This allows for the efficient conversion of the triplet excitation energy to the singlet excitation energy through reverse intersystem crossing.

[0243] For efficient excitation complex formation, it is preferable that the HOMO level of the hole-transporting material is at or above the HOMO level of the electron-transporting material. Furthermore, it is preferable that the LUMO level of the hole-transporting material is at or above the LUMO level of the electron-transporting material.

[0244] The formation of excited complexes can be confirmed, for example, by comparing the emission spectra of a hole-transporting material, an electron-transporting material, and a mixed film made by mixing these materials, and observing that the emission spectrum of the mixed film shifts to a longer wavelength than the emission spectra of each individual material (or has a new peak on the longer wavelength side). Alternatively, it can be confirmed by comparing the transient photoluminescence (PL) of a hole-transporting material, the transient PL of an electron-transporting material, and the transient PL of a mixed film made by mixing these materials, and observing differences in the transient response, such as the transient PL lifetime of the mixed film having a longer lifetime component or a larger proportion of the delayed component than the transient PL lifetime of each individual material. Furthermore, the transient PL mentioned above may be read as transient electroluminescence (EL). That is, the formation of excited complexes can also be confirmed by comparing the transient EL of a hole-transporting material, the transient EL of an electron-transporting material, and the transient EL of a mixed film made by mixing these materials, and observing the differences in the transient response.

[0245] The light-emitting layer 113 can be formed by methods such as vapor deposition (including vacuum deposition), inkjet printing, coating, and gravure printing. In addition to the materials described above, it may also contain inorganic compounds such as quantum dots or polymer compounds (oligomers, dendrimers, polymers, etc.).

[0246] Furthermore, when using a fluorescent material in the light-emitting layer, the T of the host material of the light-emitting layer is important. １ This refers to the T of the compound in the adjacent carrier transport layer (hole transport layer or electron transport layer). １ It is preferable that it be lower than this, in which case the luminescence efficiency of the light-emitting device can be increased. Preferably it is 0.2 eV or lower, and more preferably 0.5 eV or lower. Also, when a fluorescent light-emitting material is used in the light-emitting layer, the T of the host material of the light-emitting layer １ The T of the light-emitting material １ It is preferable that the temperature is lower than this. With this configuration, the light-emitting layer host material receives T from the surrounding material. １ This allows for the transfer of excitation energy, and the T of the light-emitting layer host material. １Because the density of excited states increases, TTA (Teatotic Total Acquisition) is more likely to occur in the host material, and as a result, it becomes possible to increase the luminescence efficiency. The compound having deuterium according to one aspect of the present invention is T １ Since this can increase the light emission level, it is preferable to install it in a laminate with the light emission layer. Compounds containing an anthracene skeleton are T １ Because the luminescence can be reduced, it is suitable as an example of a host material. Therefore, stacking a carrier transport layer using a deuterium-containing compound according to one aspect of the present invention and a light-emitting layer using a compound containing an anthracene skeleton as the host material is suitable for providing a device with high luminescence efficiency. However, the host material is not limited to those containing an anthracene skeleton.

[0247] Furthermore, it is preferable that the HOMO of the host material of the light-emitting layer is smaller (lower) than the HOMO of the compound in the adjacent hole transport layer. In this case, holes generated in the hole injection layer can be efficiently transported to the light-emitting layer via the hole transport layer, providing a light-emitting device with high hole transport efficiency and thus high luminescence efficiency. Specifically, the HOMO of the host material of the light-emitting layer is preferably 0.1 eV or more lower, and more preferably 0.2 eV or more lower, than the HOMO of the compound in the adjacent hole transport layer. However, if the difference in HOMO is too large, the ability to inject holes into the light-emitting layer may be reduced. Therefore, the difference between the HOMO of the host material and the HOMO of the compound in the adjacent hole transport layer is preferably 0.5 eV or less, and more preferably 0.3 eV or less. Suitable materials for obtaining such a HOMO relationship include using a compound containing deuterium according to one aspect of the present invention as the hole transport layer and using a compound containing an anthracene skeleton as the host material of the light-emitting layer.

[0248] ≪Hole Injection Layer≫ In Figure 1, the hole injection layer (111, 111a, 111b) is a layer that injects holes from the first electrode 101, which is the 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.

[0249] The hole injection layers (111, 111a, 111b) can be compounds having electron-withdrawing groups (halogen groups or cyano groups), such as 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F ４ Examples include HAT-CN, chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviated as HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviated as F6-TCNNQ), and 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene)malononitrile. In particular, compounds in which an electron-withdrawing group is bonded to a condensed aromatic ring having multiple heteroatoms, such as HAT-CN, are thermally stable and therefore preferred. Furthermore, [3]radialene derivatives having electron-withdrawing groups (especially halogen groups such as fluoro groups or cyano groups) are preferred because they have very high electron-accepting properties. Specifically, examples include α,α',α''-1,2,3-cyclopropanetriylidenates (4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile) (abbreviated as Rad), α,α',α''-1,2,3-cyclopropanetriylidenates [2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], and α,α',α''-1,2,3-cyclopropanetriylidenates [2,3,4,5,6-pentafluorobenzeneacetonitrile]. In addition to the organic compounds mentioned above, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, etc. can be used as substances with acceptor properties. Other examples include phthalocyanine (abbreviated as H ２Hole injection layers (111, 111a, 111b) can also be formed by phthalocyanine compounds such as Pc, phthalocyanine complex compounds such as copper phthalocyanine (CuPc), aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as DNTPD), or polymers such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviated as PEDOT / PSS). Accepting substances can extract electrons from adjacent hole transport layers (or hole transport materials) by applying an electric field.

[0250] Furthermore, among substances with acceptor properties, organic compounds with acceptor properties are easy to use because they have low deposition temperatures, making deposition and film formation straightforward.

[0251] Furthermore, a composite material containing the above-mentioned acceptor substance in a hole-transporting material can also be used as the hole injection layer (111, 111a, 111b). By using a composite material containing the acceptor substance in a hole-transporting material, it is possible to select the material for forming the electrode regardless of the work function. In other words, not only materials with a large work function but also materials with a small work function can be used as the anode (first electrode 101).

[0252] Various organic compounds can be used as hole-transporting materials in composite materials, including aromatic amine compounds, carbazole derivatives, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.). −６ cm ２ It is preferable that the material has a hole mobility of 1 / Vs or higher. Below, we specifically list organic compounds that can be used as hole transporting materials in composite materials.

[0253] Aromatic amine compounds that can be used in composite materials include N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviated as DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as DPAB), N,N'-bis[4-bis(3-methylphenyl)aminophenyl]-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as DNTPD), and 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviated as DPA3B). Specifically, carbazole derivatives include 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenyl Carbazole (abbreviated as PCzPCN1), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviated as TCPB), 9-[4-(10-phenyl-9-antryl)phenyl]-9H-carbazole (abbreviated as CzPA), 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene, etc. can be used.Examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviation: DNA), 9,10-diphenylanthracene (abbreviation: DPAth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert- Examples include butyl-9,10-bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-biantryl, 10,10'-diphenyl-9,9'-biantryl, 10,10'-bis(2-phenylphenyl)-9,9'-biantryl, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-biantryl, anthracene, tetracene, rubrene, perylene, and 2,5,8,11-tetra(tert-butyl)perylene. In addition, pentacene, coronene, and the like can also be used. Furthermore, it may have a vinyl skeleton. Examples of aromatic hydrocarbons having a vinyl group include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviated as DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviated as DPVPA). Organic compounds according to one embodiment of the present invention can also be used.

[0254] In addition, polymer compounds such as poly(N-vinylcarbazole) (abbreviated as PVK), poly(4-vinyltriphenylamine) (abbreviated as PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviated as PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviated as Poly-TPD) can also be used.

[0255] The hole-transporting material used in the composite material more preferably has at least one of the following skeletons: carbazole, dibenzofuran, dibenzothiophene, and anthracene. In particular, it may be an aromatic amine having substituents including a dibenzofuran ring or a dibenzothiophene ring, an aromatic monoamine having a naphthalene ring, or an aromatic monoamine in which a 9-fluorenyl group is bonded to the nitrogen of the amine via an arylene group. Furthermore, it is preferable that these organic compounds are substances having an N,N-bis(4-biphenyl)amino group, as this allows for the creation of light-emitting devices with a good lifetime. Specifically, the organic compounds described above include N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), and 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine). N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-6-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-6-amine (abbreviation: BBABnf(61,2-d]furan-8-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-8-amine (abbreviation: BBAB Ran-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation : BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4''-(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2' -Binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)tri Phenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tris(biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltri Phenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluoren]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9 H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine Examples include PCBiF (abbreviation: PCBiF), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-2-amine, and N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobio-9H-fluoren-1-amine.

[0256] Furthermore, organic compounds represented by general formulas (G1) to (G3) as described in Embodiment 1, and in particular the organic compound represented by general formula (G2) as described in Embodiment 2, can also be used.

[0257] Furthermore, it is even more preferable that the hole-transporting material used in the composite material has a relatively deep HOMO level between -5.7 eV and -5.4 eV. Having a relatively deep HOMO level in the hole-transporting material used in the composite material facilitates the injection of holes into the hole transport layer 112 and makes it easier to obtain a light-emitting device with a good lifetime. In addition, having a relatively deep HOMO level in the hole-transporting material used in the composite material moderately suppresses hole induction, resulting in a light-emitting device with an even better lifetime.

[0258] Furthermore, by mixing alkali metal or alkaline earth metal fluoride into the above composite material (preferably with an atomic ratio of fluorine atoms of 20% or more in the layer), the refractive index of the layer can be reduced. This also allows for the formation of a layer with a low refractive index inside the EL layer 103, thereby improving the external quantum efficiency of the light-emitting device. In addition, it is preferable for the hole-transporting material to have alkyl groups. The refractive index can be lowered by having alkyl groups. Examples of alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, hexyl group, isohexyl group, n-hexyl group, 3-methylpentyl group, 2-methylpentyl group, 2-ethylbutyl group, 1,2-dimethylbutyl group, and 2,3-dimethylbutyl group, and it is particularly preferable to have multiple alkyl groups. A material with low refractive index and hole transport properties can be laminated with a layer containing a deuterium compound according to one aspect of the present invention, thereby efficiently extracting emitted light to the outside and improving the external quantum efficiency of the light-emitting device. Furthermore, as the external quantum efficiency increases, the current density required to obtain the necessary brightness decreases, thus improving reliability in continuous operation tests. For example, by having one methyl group, the refractive index (e.g., the ordinary refractive index n) can be improved. ｏ The refractive index can be reduced by 0.02. Therefore, the refractive index can be further reduced by having multiple alkyl groups. For example, it is preferable that the number of alkyl groups be two or more, four or more, six or more, or eight or more. However, if there are too many alkyl groups, the compound may decompose easily during deposition, and the carrier mobility may decrease, so it is preferable that the number of alkyl groups be 10 or less. Compounds having multiple methyl groups or tert-butyl groups, or both, are particularly suitable for achieving both high external quantum efficiency and high carrier mobility.

[0259] By forming hole injection layers (111, 111a, 111b), hole injection performance is improved, and a light-emitting device with a low driving voltage can be obtained.

[0260] ≪Hole Transport Layer≫ In Figure 1, the hole transport layer (112, 112a, 112b) is a layer containing a hole transport material, and the hole transport material exemplified can be used as the material for the hole injection layer (111, 111a, 111b). Since the hole transport layer (112, 112a, 112b) has the function of transporting holes injected into the hole injection layer (111, 111a, 111b) to the light-emitting layer (113, 113a, 113b), it is preferable that it has the same or close HOMO level as the HOMO level of the hole injection layer (111, 111a, 111b).

[0261] Furthermore, the hole transport layer is 1 × 10 −６ cm ２ It is preferable that the material has a hole mobility of 1 / Vs or higher. However, any material with a hole mobility other than those specified may be used, as long as it has higher hole transportability than electron transportability. Furthermore, the layer containing the material with high hole transportability may be a single layer, or two or more layers containing the above material may be stacked.

[0262] For example, when laminating hole transport layers, it is preferable to use a material with high electron-blocking properties on the side in contact with the light-emitting layer. Specifically, if the LUMO level of the hole transport layer provided in contact with the light-emitting layer is higher than the LUMO level of the material constituting the light-emitting layer (at least the host material), it may exhibit excellent function as an electron-blocking layer. In this case, it is preferable, and more preferably, that the LUMO level of the hole transport layer is 0.3 eV higher than the LUMO level of the material constituting the light-emitting layer (at least the host material) from the viewpoint of improving luminous efficiency.

[0263] Materials that can be used for the hole transport layer (112, 112a, 112b) include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviated as NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviated as TPD), N,N'-bis(9,9'-spirobi[9H-fluoren]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviated as BSPB), and 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviated as BP AFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4 ''-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluoren-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9'-spirobi[9H-fluoren]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9 ,9-dimethyl-9H-fluoren-2-amine (abbreviation: PCBiF), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophen-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBA βNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB), 4,4'-diphenyl-4''-(7;1'-binaphthyl-2-yl)triphenylamine (abbreviation: BBAαNβNB-03), 4,4'-diphenyl-4''-(7-phenyl)naphthyl-2-yltriphenylamine (abbreviation: BBAPβNB-03), 4,4'-diphenyl-4' '−(6;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B), 4,4'-diphenyl-4''-(7;2'-binaphthyl-2-yl)triphenylamine (abbreviation: BBA(βN2)B-03), 4,4'-diphenyl-4''-(4;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB), 4,4'-diphenyl-4''-(5;2'-binaphthyl-1-yl)triphenylamine (abbreviation: BBAβNαNB-02), 4-(4-biphenylyl)-4'-(2-naphthyl)- 4''-phenyltriphenylamine (abbreviation: TPBiAβNB), 4-(3-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: mTPBiAβNBi), 4-(4-biphenylyl)-4'-[4-(2-naphthyl)phenyl]-4''-phenyltriphenylamine (abbreviation: TPBiAβNBi), 4-phenyl-4'-(1-naphthyl)triphenylamine (abbreviation: αNBA1BP), 4,4'-bis(1-naphthyl)triphenylamine (abbreviation: αNBB1BP), 4,4'-diphenyl-4''-[4'-(carbazole-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazole-9-yl)phenyl]tris(biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazole-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-N-[4-(1 -Naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-3-amine, N,N- Compounds having an aromatic amine skeleton such as bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluoren-1-amine, 1,3-bis(N-carbazolyl)benzene (abbreviation: mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviation: CzTP), 9,9'-diphenyl-9H,9'H-3,Compounds having a carbazole skeleton such as 3'-bicarbazole (abbreviation: PCCP), 9,9'-bis(biphenyl-3-yl)-3,3'-bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCP), 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluoren-9-yl)] Examples include compounds having a thiophene skeleton such as nyl]dibenzothiophene (abbreviated as DBTFLP-III) and 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as DBTFLP-IV), and compounds having a furan skeleton such as 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviated as DBF3P-II) and 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as mmDBFFLBi-II). Among the above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferred because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. Furthermore, the materials listed as having hole transportability used in the composite material of the hole injection layer 111 can also be suitably used as materials constituting the hole transport layer 112.

[0264] Furthermore, organic compounds represented by general formulas (G1) to (G3) as described in Embodiment 1, and in particular the organic compound represented by general formula (G2) as described in Embodiment 2, can also be used.

[0265] ≪Electron Transport Layer≫ In Figure 1, the electron transport layers (114, 114a, 114b) have the function of transporting electrons injected from the other electrode of the pair (first electrode 101 or second electrode 102) to the light-emitting layer 113 via the electron injection layers (115, 115a, 115b).

[0266] Furthermore, as an electron-transporting material, it is an organic compound having electron-transporting properties, and the electron mobility at which the square root of the electric field strength [V / cm] is 600 is 1 × 10⁻⁶.−６ cm ２ A substance having an electron mobility of 1 / Vs or higher is preferred. However, any substance that has higher electron transport than holes can be used. As the above organic compound, an organic compound having a π-electron-deficient heteroaromatic ring is preferred. As an organic compound having a π-electron-deficient heteroaromatic ring, it is preferable that it be any or more of the following: an organic compound containing a heteroaromatic ring having an azole skeleton, an organic compound containing a heteroaromatic ring having a pyridine skeleton, an organic compound containing a heteroaromatic ring having a diazine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton.

[0267] Organic compounds having a π-electron-deficient heteroaromatic ring that can be used in the above electron transport layer include, specifically, 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), 1,3-bis[5-(4-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviated as OXD-7), and 9-[4-(5-phenyl-1,3,4-oxadiazole-2-yl]benzene. Organic compounds having an azole skeleton, such as sadiazole-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4'-bis(5-methylbenzoxazole-2-yl)stilbene (abbreviation: BzOs), and 3,5-bis[3-(9H-carbazole-9-yl)phenyl Organic compounds containing heteroaromatic rings with a pyridine skeleton, such as [nyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[(3-pyridyl)phenyl-3-yl]benzene (abbreviation: TmPyPB), vasophenanthroline (abbreviation: Bphen), vasocuproin (abbreviation: BCP), 2,9-di(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBphen), 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-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4'-(9-phenyl-9H-carbazole-3-yl)-3,1'-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]dibenzo[f,[h]Quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]Quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(dibenzothiophen-4-yl)phenyl]dibenzo[f,h]Quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3'-(dibenzothiophen-4-yl)biphenyl -4-yl]naphtho[1',2':4,5]flo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9'-[pyrimidine-4,6-diylbis(biphenyl-3,3'-diyl)]bis(9 H-carbazole) (abbreviation: 4,6mCzBP2Pm), 8-(biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflo[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-bis[3-(dibenzothiophen-4-yl)phenyl]benzoflo[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 8-[3'-(dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1',2':4,5]flo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfp m), 8-[(2,2'-binaphthalene)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzoflozyrimidine[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2'-(pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(biphenyl-3-yl)-4-[3,5-Bis(9H-carbazole-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,4-Bis[4-(1-naphthyl)phenyl]-6-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazole-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazole-2-yl)quinazoline-2-yl]-7H-dibenzo[c,g]cal Organic compounds having a diazine skeleton, such as Bazole (abbreviation: PC-cgDBCzQz), 2-[3'-(9,9-dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTZn), 2-(biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobio[9H-fluoren]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTZn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1 ,3,5-triazine (abbreviation: mBnfBPTZn), 2-{3-[3-(benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTZn-02), 9-[4-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: PCCzPTZn), 9-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-9'-phenyl-2,3'-bi-9H-carbazole (abbreviation: mPCCzPTZn-02), 5-[3-(4,6-diphenyl-1,3,5-triazine-2-yl)phenyl]-7,7-dimethyl-5H,7H-indeno[2,1-b]carbazole (abbreviation: mINc(II)PTZn), 2-{3-[3-(dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTZn), 2,4,6-tris[3'-(pyridine-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-dimethyl-3-pyridinyl)-5-(9-phenanthryl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTZn), 11-[4-(biphenyl-4-yl)-6-phenyl-1,3,5-triazine-2-yl]-11,12-dihydro-12-phenylindoro[2,3-a]carbazole (abbreviation: BP-Icz(II)TZn), 2-[3'-(triphenylene-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3 Examples of organic compounds having a triazine skeleton include 5-triazine (abbreviated as mTpBPTZn), 3-[9-(4,6-diphenyl-1,3,5-triazine-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviated as PCDBfTZn), and 2-(biphenyl-3-yl)-4-phenyl-6-{8-[(1,1':4',1''-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviated as mBP-TPDBfTZn). Among the above, organic compounds containing a heteroaromatic ring having a diazine skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton are preferred due to their good reliability. In particular, organic compounds containing heteroaromatic rings with a diazine (pyrimidine and pyrazine) skeleton, and organic compounds containing heteroaromatic rings with a triazine skeleton, exhibit high electron transport properties and contribute to reducing the driving voltage.

[0268] Furthermore, by laminating an electron transport layer containing an organic compound having an azine skeleton, a light-emitting layer containing an organic compound having an anthracene skeleton, and a hole transport layer containing a deuterium-containing compound according to one aspect of the present invention, the reliability of continuous operation of the organic device is improved and the driving voltage is reduced. In addition, by laminating a material with low refractive index and hole transport properties, an organic device with improved external quantum efficiency can be provided. As a result, the current density required to obtain high brightness can be reduced, making it possible to provide a light-emitting device with reduced power consumption. In particular, by laminating an integrated configuration, namely a hole transport layer containing an alkyl group, a hole transport layer containing a deuterium-containing compound according to one aspect of the present invention, a light-emitting layer having an anthracene skeleton, and an electron transport layer having a triazine skeleton, the characteristics of the organic device can be improved, and an organic device with improved heat resistance or stability can be provided.

[0269] Furthermore, the electron transport layers (114, 114a, 114b) may be not only a single layer, but also two or more layers containing the above-mentioned material.

[0270] Furthermore, a layer for controlling the movement of electron carriers may be provided between the electron transport layers (114, 114a, 114b) and the light-emitting layers (113, 113a, 113b). This layer is made by adding a small amount of a substance with high electron-trapping properties to the electron-transporting material described above, and it is possible to adjust the carrier balance by suppressing the movement of electron carriers. Such a configuration is highly effective in suppressing problems that occur when electrons penetrate the light-emitting layer (for example, a decrease in device lifespan).

[0271] ≪Electron injection layer≫ In Figure 1, the electron injection layers (115, 115a, 115b) have the function of promoting electron injection by reducing the electron injection barrier from the second electrode 102.

[0272] Furthermore, for example, Group 1 metals, Group 2 metals, or their oxides, halides, carbonates, etc., can be used. Also, composite materials of the electron-transporting material and an electron-donating material can be used. Examples of electron-donating materials include Group 1 metals, Group 2 metals, or their oxides. Specifically, lithium fluoride (LiF), sodium fluoride (NaF), cesium fluoride (CsF), calcium fluoride (CaF) ２ ), lithium oxide (LiO ｘ Alkali metals, alkaline earth metals, or compounds thereof, such as ) can be used. Also, erbium fluoride (ErF) can be used. ３ Rare earth metal compounds such as ) can be used. Alternatively, an electride may be used in the electron injection layer 115. Examples of such electrides include a substance obtained by adding electrons to a mixed oxide of calcium and aluminum at a high concentration. Furthermore, the electron injection layers (115, 115a, 115b) may be made of a substance that can be used in the electron transport layers (114, 114a, 114b).

[0273] Furthermore, a composite material obtained by mixing an organic compound and an electron donor may be used in the electron injection layers (115, 115a, 115b). Such a composite material has excellent electron injection and electron 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 in transporting the generated electrons, and specifically, for example, the substance that constitutes the electron transport layer 114 described above (metal complex, or heteroaromatic compound, etc.) can be used. As the electron donor, any substance that exhibits electron-donating properties to the organic compound is acceptable. 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 also preferred, such as lithium oxide, calcium oxide, and barium oxide. Lewis bases such as magnesium oxide can also be used. Furthermore, organic compounds such as tetrathiafulvalene (abbreviated as TTF) can also be used.

[0274] The light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer described above can be formed by methods such as vapor deposition (including vacuum deposition), inkjet printing, coating, and gravure printing. In addition to the materials described above, inorganic compounds such as quantum dots or polymer compounds (oligomers, dendrimers, polymers, etc.) may also be used for the light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer.

[0275] Furthermore, the quantum dots may include colloidal quantum dots, alloy quantum dots, core-shell quantum dots, core quantum dots, etc. Quantum dots containing elemental groups from groups 2 and 16, 13 and 15, 13 and 17, 11 and 17, or 14 and 15 may also be used. Alternatively, 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 be used.

[0276] <Pair of electrodes> The first electrode 101 and the second electrode 102 function as the anode or cathode of the light-emitting device. The first electrode 101 and the second electrode 102 can be formed using metals, alloys, conductive compounds, mixtures thereof, or laminates.

[0277] Preferably, one of the first electrode 101 or the second electrode 102 is formed of a conductive material having the function of reflecting light. Examples of such conductive materials include aluminum (Al) or alloys containing Al. Examples of alloys containing Al include alloys containing Al and L (where 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 has low resistance and high light reflectivity. In addition, since aluminum is abundant in the Earth's crust and inexpensive, using aluminum can reduce the cost of manufacturing light-emitting devices. In addition, alloys containing silver (Ag), or Ag and N (where 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 silver-containing alloys 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 such as tungsten, chromium (Cr), molybdenum (Mo), copper, and titanium can also be used.

[0278] Furthermore, the light emitted from the light-emitting layer is extracted through one or both of the first electrode 101 and the second electrode 102. Therefore, it is preferable that at least one of the first electrode 101 and the second electrode 102 be made of a conductive material that has the function of transmitting light. The conductive material has a visible light transmittance of 40% to 100%, preferably 60% to 100%, and a resistivity of 1 × 10⁻¹⁶. −２ Examples of conductive materials include those with a conductivity of Ω·cm or less.

[0279] Furthermore, the first electrode 101 and the second electrode 102 may be formed from a conductive material having the function of transmitting light and the function of reflecting light. The conductive material has a visible light reflectance of 20% to 80%, preferably 40% to 70%, and a resistivity of 1 × 10⁻⁶. −２ Examples of conductive materials include those with a conductivity of Ω·cm or less. For example, they can be formed using one or more types of conductive metals, alloys, or conductive compounds. Specifically, for example, metal oxides such as indium tin oxide (ITO), indium tin oxide containing silicon or silicon oxide (abbreviated as ITSO), indium zinc oxide, indium tin oxide containing titanium, indium titanium oxide, tungsten oxide, and indium oxide containing zinc oxide can be used. In addition, a thin metal film that transmits light (preferably with a thickness of 1 nm to 30 nm) can be used. As a metal, for example, Ag can be used. As an alloy, alloys such as Ag and Al, Ag and Mg, Ag and Au, Ag and Yb can be used.

[0280] In this specification, a material having the function of transmitting light is any material that has the function of transmitting visible light and is conductive. For example, in addition to oxide conductors represented by ITO as described above, this includes oxide semiconductors or organic conductors containing organic matter. Examples of organic conductors containing organic matter include composite materials obtained by mixing an organic compound with an electron donor, and composite materials obtained by mixing an organic compound with an electron acceptor. Inorganic carbon-based materials such as graphene may also be used. The resistivity of the material is preferably 1 × 10⁻⁶. ５ Ω·cm or less, more preferably 1 × 10⁻⁶ ４ It is less than or equal to Ω·cm.

[0281] Alternatively, one or both of the first electrode 101 and the second electrode 102 may be formed by stacking multiple of the above materials.

[0282] Furthermore, to improve light extraction efficiency, a material with a higher refractive index than the electrode may be formed in contact with an electrode that has the function of transmitting light. Such a material can be any material that has the function of transmitting visible light, and may or may not be conductive. For example, in addition to the oxide conductors mentioned above, oxide semiconductors and organic materials can be used. Examples of organic materials include the materials exemplified in the light-emitting layer, hole injection layer, hole transport layer, electron transport layer, or electron injection layer. Inorganic carbon-based materials or thin metal films that transmit light to a certain extent can also be used, and multiple layers of several nanometers to tens of nanometers may be stacked.

[0283] When the first electrode 101 or the second electrode 102 functions as a cathode, it is preferable to use a material with a small work function (3.8 eV or less). For example, elements belonging to Group 1 or Group 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.

[0284] Furthermore, when using the first electrode 101 or the second electrode 102 as an anode, it is preferable to use a material with a large work function (4.0 eV or more).

[0285] Furthermore, the first electrode 101 and the second electrode 102 may be laminates of a conductive material having the function of reflecting light and a conductive material having the function of transmitting light. In that case, the first electrode 101 and the second electrode 102 are preferable because they can have a function of adjusting the optical distance so that they can resonate with the desired light from each light-emitting layer and intensify the light of that wavelength.

[0286] The first electrode 101 and the second electrode 102 can be deposited using methods such as sputtering, vapor deposition, printing, coating, MBE (Molecular Beam Epitaxy), CVD, pulsed laser deposition, ALD (Atomic Layer Deposition), etc., as appropriate.

[0287] ≪Charge Generation Layer (Intermediate Layer)≫ In Figures 5B and 5D, the charge generation layer 106 has the function of injecting electrons into the organic compound layer 103a and 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 configuration in which an electron acceptor is added to a hole transport material (also called a p-type layer), or a configuration in which an electron donor is added to an electron transport material (also called an electron injection buffer layer). Furthermore, both of these configurations may be laminated. In addition, an electron relay layer may be provided between the p-type layer and the electron injection buffer layer. By forming the charge generation layer 106 using the materials described above, it is possible to suppress the increase in driving voltage when an organic compound layer including an emissive layer is laminated.

[0288] In Figure 5E, when a voltage is applied between the first electrode (anode) 101 and the second electrode (cathode) 102, the charge generation layers 106a and 106b have the function of injecting electrons into the organic compound layer 103a and holes into the organic compound layer 103b, while the charge generation layer 106b has the function of injecting electrons into the organic compound layer 103b and holes into the organic compound layer 103c. The explanation of charge generation layers 106a and 106b is the same as that of charge generation layer 106, so it is omitted.

[0289] In charge generation layers 106, 106a, and 106b, when an electron acceptor is added to a hole-transporting material which is an organic compound (p-type layer), the hole-transporting material shown in this embodiment can be used as the hole-transporting material. Furthermore, as the electron acceptor, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as F) can be used. ４Examples include chlororanil (-TCNQ), α,α',α''-1,2,3-cyclopropanetriylidenateris (4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile) (abbreviation: Rad), etc. Also, oxides of metals belonging to groups 4 to 8 of the periodic table can be used. Specifically, examples include vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide. The above-mentioned acceptor materials may also be used. Furthermore, the materials constituting the p-type layer may be used as a mixed film, or single films containing each material may be laminated.

[0290] Furthermore, in the charge generation layer 106, charge generation layer 106a, and charge generation layer 106b, if an electron donor is added to the electron transport material (electron injection buffer layer), the electron transport material shown in this embodiment can be used.

[0291] Furthermore, alkali metals, alkaline earth metals, rare earth metals, or metals belonging to groups 2 and 13 of the periodic table, as well as their oxides and carbonates, can be used as electron donors. Specifically, lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), ytterbium (Yb), indium (In), lithium oxide (Li) ２ It is preferable to use o), cesium carbonate, etc. Alternatively, an organic compound such as tetrathianaphthalene may be used as an electron donor.

[0292] In charge generation layers 106, 106a, and 106b, when an electron relay layer is provided between the p-type layer and the electron injection buffer layer, the electron relay layer contains at least an electron-transporting material and has the function of preventing interaction between the electron injection buffer layer and the p-type layer and smoothly transferring electrons. Preferably, the LUMO level of the electron-transporting material included in the electron relay layer is between the LUMO level of the acceptor material in the p-type layer and the LUMO level of the electron-transporting material included 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 material used in the electron relay layer is preferably -5.0 eV or higher, more preferably -5.0 eV or higher and -3.0 eV or lower. Preferably, as the electron-transporting material used in the electron relay layer, a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand is used.

[0293] In Figure 5D, a configuration is shown in which two organic compound layers 103, namely organic compound layer 103a and organic compound layer 103b, are stacked. However, by providing a charge generation layer between different light-emitting layers, a stacked structure of organic compound layers containing three or more light-emitting layers is also possible. Figure 5E shows the configuration when organic compound layers containing three light-emitting layers are stacked.

[0294] <<Cap Layer>> Although not shown in Figures 5A to 5E, a cap layer may be provided on the second electrode 102 of the light-emitting device. For example, a material with a high refractive index can be used for the cap layer. By providing a cap layer on the second electrode 102, the extraction efficiency of the light emitted from the second electrode 102 can be improved.

[0295] Specific examples of materials that can be used in the cap layer include 5,5'-diphenyl-2,2'-di-5H-[1]benzothieno[3,2-c]carbazole (abbreviated as BisBTc) and 4,4',4''-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviated as DBT3P-II).

[0296] Furthermore, organic compounds represented by general formulas (G1) to (G3) as described in Embodiment 1, and in particular the organic compound represented by general formula (G2) as described in Embodiment 2, can also be used.

[0297] <Substrate> Furthermore, a light-emitting device according to one aspect of the present invention may be manufactured on a substrate made of glass, plastic, or the like. The order in which the components are manufactured on the substrate may be either by stacking them sequentially from the first electrode 101 side, or by stacking them sequentially from the second electrode 102 side.

[0298] In addition, as a substrate on which a light-emitting device according to one aspect 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 substrate that can be bent (flexible), and examples include plastic substrates made of polycarbonate or polyarylate. Films, inorganic vapor-deposited films, etc., can also be used. In addition, other materials are acceptable as long as they function as a support in the manufacturing process of the light-emitting device and optical device. Alternatively, any material that has the function of protecting the light-emitting device and optical device is acceptable.

[0299] For example, in this specification, light-emitting devices can be formed using various substrates. The type of substrate is not particularly limited. Examples of substrates include semiconductor substrates (e.g., single-crystal substrates such as silicon substrates), SOI 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, or base films. Examples of glass substrates include barium borosilicate glass, aluminobosilicate glass, or soda-lime glass. Examples of flexible substrates, laminated films, and base films include the following: For example, plastics such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), and polytetrafluoroethylene (PTFE). Alternatively, as an example, acrylic resin. Alternatively, as an example, polypropylene, polyester, polyvinyl fluoride, or polyvinyl chloride. Alternatively, examples include resins such as polyamide, polyimide, aramid, or epoxy, inorganic vapor-deposited films, or papers.

[0300] Alternatively, a flexible substrate may be used as the substrate, and the light-emitting device may be formed directly on the flexible substrate. Or, a release layer may be provided between the substrate and the light-emitting device. The release layer can be used to separate the light-emitting device from the substrate after it has been partially or completely completed on it, and to transfer it to another substrate. In this case, the light-emitting device can be transferred to a substrate with poor heat resistance or a flexible substrate. The release layer can be configured in various ways, such as a laminated inorganic film structure of a tungsten film and a silicon oxide film, or a resin film such as polyimide formed on the substrate.

[0301] In other words, a light-emitting device may be formed using one substrate, then the light-emitting device may be transferred to another substrate, and the light-emitting device may be placed on the other substrate. Examples of substrates to which the light-emitting device is transferred include, in addition to the substrates mentioned above, cellophane substrates, stone substrates, wood substrates, cloth substrates (including natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester), or recycled fibers (acetate, cupro, rayon, recycled polyester), etc.), leather substrates, or rubber substrates. By using these substrates, it is possible to create light-emitting devices that are less prone to breakage, have high heat resistance, are lightweight, or are thin.

[0302] Alternatively, a field-effect transistor (FET), for example, may be formed on the aforementioned substrate, and a light-emitting device may be fabricated on an electrode electrically connected to the FET. This makes it possible to fabricate an active-matrix type display device in which the driving of the light-emitting device is controlled by the FET.

[0303] In this embodiment, one aspect of the present invention has been described. Alternatively, in other embodiments, one aspect of the present invention may be described. However, the aspects of the present invention are not limited to these. In other words, since various aspects of the invention are described in this embodiment and other embodiments, the aspects of the present invention are not limited to a specific aspect. For example, an example of application to a light-emitting device was shown as one aspect of the present invention, but the aspects of the present invention are not limited to this. For example, depending on the circumstances, one aspect of the present invention may not be applied to a light-emitting device. Alternatively, for example, in one aspect of the present invention, an example was shown in which a first organic compound, a second organic compound, and a guest material having the function of converting triplet excitation energy into light emission are provided, and the LUMO level of the first organic compound is lower than the LUMO level of the second organic compound, and the HOMO level of the first organic compound is lower than the HOMO level of the second organic compound, but the aspects of the present invention are not limited to this. Depending on the circumstances, or depending on the situation, in one aspect of the present invention, for example, the LUMO level of the first organic compound does not have to be lower than the LUMO level of the second organic compound. Or, the HOMO level of the first organic compound does not have to be lower than the HOMO level of the second organic compound. Or, for example, in one aspect of the present invention, an example is shown in which the first organic compound and the second organic compound form an excited complex, but the aspects of the present invention are not limited thereto. Depending on the circumstances, or depending on the situation, in one aspect of the present invention, for example, the first organic compound and the second organic compound do not have to form an excited complex. Or, for example, in one aspect of the present invention, an example is shown in which the LUMO level of the guest material is higher than the LUMO level of the first organic compound, and the HOMO level of the guest material is lower than the HOMO level of the second organic compound, but the aspects of the present invention are not limited thereto. In some cases, or depending on the circumstances, in one aspect of the present invention, for example, 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.

[0304] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments.

[0305] (Embodiment 4) The light-emitting device 130 constitutes a display device formed in multiple locations on the insulating layer 175, as illustrated in Figures 6A and 6B. In this embodiment, a display device according to one aspect of the present invention will be described in detail.

[0306] The display device 100 has a pixel section 177 in which a plurality of pixels 178 are arranged in a matrix. The pixels 178 include sub-pixels 110R, sub-pixels 110G, and sub-pixels 110B.

[0307] In this specification, when describing matters common to, for example, sub-pixels 110R, 110G, and 110B, they may be referred to simply as sub-pixel 110. Similarly, when describing matters common to other components distinguished by letters, the letters may be omitted and the corresponding symbols used.

[0308] Sub-pixel 110R emits red light, sub-pixel 110G emits green light, and sub-pixel 110B emits blue light. This allows an image to be displayed on the pixel section 177. In this embodiment, three sub-pixels of red (R), green (G), and blue (B) are used as an example, but combinations of other colors of sub-pixels may also be used. Furthermore, the number of sub-pixels is not limited to three, but may be four or more. Examples of four sub-pixels include four sub-pixels of R, G, B, and white (W), four sub-pixels of R, G, B, and yellow (Y), and four sub-pixels of R, G, B, and infrared (IR).

[0309] In this specification and other documents, the row direction may be referred to as the X direction and the column direction as the Y direction. The X and Y directions intersect, for example, perpendicularly.

[0310] Figure 6A shows an example where subpixels of different colors are arranged in the X direction, and subpixels of the same color are arranged in the Y direction. Alternatively, subpixels of different colors may be arranged in the Y direction, and subpixels of the same color may be arranged in the X direction.

[0311] A connecting portion 140 and a region 141 may be provided on the outside of the pixel portion 177. The region 141 is provided between the pixel portion 177 and the connecting portion 140. An organic compound layer 103 is provided in the region 141. A conductive layer 151C is provided in the connecting portion 140.

[0312] Figure 6A shows an example where region 141 and connection portion 140 are located to the right of the pixel portion 177, but the positions of region 141 and connection portion 140 are not particularly limited. Also, region 141 and connection portion 140 may be singular or multiple.

[0313] Figure 6B is an example of a cross-sectional view between the dashed line A1-A2 in Figure 6A. As shown in Figure 6A, the display device 100 has 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 is provided on a substrate (not shown). The insulating layer 175, insulating layer 174, and insulating layer 173 are provided with openings that reach the conductive layer 172, and plugs 176 are provided to fill these openings.

[0314] In the pixel section 177, a light-emitting device 130 is provided on an insulating layer 175 and a plug 176. A protective layer 131 is provided so as to cover the light-emitting device 130. A substrate 120 is bonded to the protective layer 131 by a resin layer 122. Preferably, an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided between adjacent light-emitting devices 130.

[0315] In Figure 6B, multiple cross-sections of the inorganic insulating layer 125 and the insulating layer 127 are shown, but when the display device 100 is viewed from above, it is preferable that the inorganic insulating layer 125 and the insulating layer 127 are connected as one unit. In other words, it is preferable that the insulating layer 127 is an insulating layer having an opening on the first electrode.

[0316] In Figure 6B, the light-emitting device 130 is shown as light-emitting device 130R, light-emitting device 130G, and light-emitting device 130B. Light-emitting devices 130R, 130G, and 130B emit different colors from each other. For example, light-emitting device 130R can emit red light, light-emitting device 130G can emit green light, and light-emitting device 130B can emit blue light. In addition, light-emitting devices 130R, 130G, or 130B may emit other visible light or infrared light.

[0317] One embodiment of the present invention can be a top-emission type, for example, which emits light in the opposite direction to the substrate on which the light-emitting device is formed. Alternatively, one embodiment of the present invention may be a bottom-emission type.

[0318] Examples of light-emitting materials in the light-emitting device 130 include organic compounds or organometallic complexes such as fluorescent substances (fluorescent compounds), phosphorescent substances (phosphorescent compounds), and thermally activated delayed fluorescence (thermally activated delayed fluorescence (TADF) materials). Inorganic compounds such as quantum dots may also be used.

[0319] The light-emitting device 130R has the configuration shown in Figure 1A. It includes a first electrode (pixel electrode) consisting of a conductive layer 151R and a conductive layer 152R, an organic compound layer 103R on the first electrode, a common layer 104 on the organic compound layer 103R, and a second electrode (common electrode) 102 on the common layer. The common layer 104 may or may not be provided, but its provision is preferable because it reduces damage to the organic compound layer 103R during processing. If the common layer 104 is provided, it is preferable that the common layer 104 is an electron injection layer. Furthermore, if the common layer 104 is provided, the laminated structure of the organic compound layer 103R and the common layer 104 corresponds to the organic compound layer 103 in Embodiment 3.

[0320] The light-emitting device 130G has the configuration shown in Figure 1A. It includes a first electrode (pixel electrode) consisting of a conductive layer 151G and a conductive layer 152G, an organic compound layer 103G on the first electrode, a common layer 104 on the organic compound layer 103G, and a second electrode (common electrode) 102 on the common layer. The common layer 104 may or may not be provided, but its provision is preferable because it reduces damage to the organic compound layer 103G during processing. If the common layer 104 is provided, it is preferable that the common layer 104 is an electron injection layer. Furthermore, if the common layer 104 is provided, the laminated structure of the organic compound layer 103G and the common layer 104 corresponds to the organic compound layer 103 in Embodiment 3.

[0321] The light-emitting device 130B has the configuration shown in Figure 1A. It includes a first electrode (pixel electrode) consisting of a conductive layer 151B and a conductive layer 152B, an organic compound layer 103B on the first electrode, a common layer 104 on the organic compound layer 103B, and a second electrode (common electrode) 102 on the common layer. The common layer 104 may or may not be provided, but its provision is preferable because it reduces damage to the organic compound layer 103B during processing. If the common layer 104 is provided, it is preferable that the common layer 104 is an electron injection layer. Furthermore, if the common layer 104 is provided, the laminated structure of the organic compound layer 103B and the common layer 104 corresponds to the organic compound layer 103 in Embodiment 3.

[0322] Of the pixel electrodes and common electrodes in a light-emitting device, one functions as the anode and the other as the cathode. In the following explanation, unless otherwise specified, it is assumed that the pixel electrodes function as the anode and the common electrodes function as the cathode.

[0323] The organic compound layers 103R, 103G, and 103B are independently arranged in island-like formations for each sub-pixel or each light-emitting color. By providing the organic compound layer 103 in island-like formations for each light-emitting device 130, leakage current between adjacent light-emitting devices 130 can be suppressed even in high-definition display devices. This prevents crosstalk and enables the realization of a display device with extremely high contrast. In particular, it enables the realization of a display device with high current efficiency at low brightness.

[0324] The island-shaped organic compound layer 103 is formed by depositing an EL film and processing the EL film using a lithography method.

[0325] Furthermore, in a display device according to one aspect of the present invention, it is preferable that the first electrode (pixel electrode) of the light-emitting device be in a stacked configuration. For example, in the example shown in Figure 6B, the first electrode of the light-emitting device 130 is in a stacked configuration of a conductive layer 151 and a conductive layer 152. For example, when the display device 100 is a top-emission type and the pixel electrode of the light-emitting device 130 functions as an anode, it is preferable that the conductive layer 151 is a layer with high reflectivity for visible light, and the conductive layer 152 is a layer that, for example, transmits visible light and has a large work function. When the display device 100 is a top-emission type, the higher the reflectivity of the pixel electrode for visible light, the higher the efficiency of extracting light emitted by the organic compound layer 103. Also, when the pixel electrode functions as an anode, the larger the work function of the pixel electrode, the easier it is to inject holes into the organic compound layer 103. Based on the above, by making the pixel electrodes of the light-emitting device 130 a stacked structure consisting of a conductive layer 151 with high reflectivity for visible light and a conductive layer 152 with a large work function, the light-emitting device 130 can be made into a light-emitting device with high light extraction efficiency and low driving voltage.

[0326] When the conductive layer 151 is a layer with high reflectivity to visible light, it is preferable that the reflectivity of the conductive layer 151 to visible light be, for example, 40% to 100% or 70% to 100%. Furthermore, when the conductive layer 152 is an electrode that transmits visible light, it is preferable that its transmittance to visible light be, for example, 40% or more.

[0327] In cases where the pixel electrode has a stacked structure consisting of multiple layers, the pixel electrode may be altered due to reactions between these layers, for example. For instance, when a film formed after the pixel electrode is created is removed by a wet etching method, galvanic corrosion may occur when the chemical solution comes into contact with the pixel electrode.

[0328] Therefore, in the display device 100 of this embodiment, an insulating layer 156 is formed on the side surfaces of the conductive layer 151 and the conductive layer 152. This makes it possible to suppress contact of the chemical solution with the conductive layer 151 even when removing a film formed after the formation of a pixel electrode having the conductive layer 151 and the conductive layer 152 by a wet etching method. Consequently, the occurrence of galvanic corrosion on the pixel electrode can be suppressed. As a result, the display device 100 can be manufactured using a method with a high yield, making it a low-cost display device. Furthermore, since the occurrence of defects in the display device 100 can be suppressed, the display device 100 can be a highly reliable display device.

[0329] For example, a metallic material can be used as 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), and alloys containing these in appropriate combinations can also be used.

[0330] As the conductive layer 152, an oxide having one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, it is preferable to use a conductive oxide containing one or more of the following: 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, so it can be suitably used as the conductive layer 152.

[0331] The conductive layer 151 may be a laminated structure of multiple layers having different materials, and the conductive layer 152 may be a laminated structure of multiple layers having different materials. In this case, the conductive layer 151 may have a layer made of a material that can be used for the conductive layer 152, such as a conductive oxide, and the conductive layer 152 may have a layer made of a material that can be used for the conductive layer 151, such as a metallic material. For example, if the conductive layer 151 has a laminated structure of two or more layers, the layer in contact with the conductive layer 152 may be a layer made of a material that can be used for the conductive layer 152.

[0332] Furthermore, the ends of the insulating layer 156 may have a tapered shape. Specifically, by having the ends of the insulating layer 156 have a tapered shape with a taper angle of less than 90°, the coverage of structures provided along the side surface of the insulating layer 156 can be improved.

[0333] (Embodiment 5) In this embodiment, a light-emitting device according to one aspect of the present invention will be described with reference to Figures 7A to 7G and Figures 8A to 8I.

[0334] [Pixel Layout] In this embodiment, a pixel layout different from that shown in Figure 6A will be described. There are no particular limitations on the arrangement of subpixels, and various methods can be applied. Examples of subpixel arrangements include stripe arrangements, S-stripe arrangements, matrix arrangements, delta arrangements, Bayer arrangements, and pentile arrangements.

[0335] In this embodiment, the upper surface shape of the sub-pixel shown in the figure corresponds to the upper surface shape of the light-emitting region.

[0336] Examples of the top surface shape of a sub-pixel include polygons such as triangles, quadrilaterals (including rectangles and squares), pentagons, polygons with rounded corners, ellipses, or circles.

[0337] Furthermore, the circuit layout constituting the sub-pixel is not limited to the sub-pixel range shown in the figure, but may be arranged outside of it.

[0338] The pixel 178 shown in Figure 7A has an S-stripe array applied to it. The pixel 178 shown in Figure 7A is composed of three subpixels: subpixel 110R, subpixel 110G, and subpixel 110B.

[0339] The pixel 178 shown in Figure 7B includes a sub-pixel 110R having a roughly trapezoidal or triangular shape with rounded corners, a sub-pixel 110G having a roughly trapezoidal or triangular shape with rounded corners, and a sub-pixel 110B having a roughly square or hexagonal top surface shape with rounded corners. Furthermore, sub-pixel 110R has a larger light-emitting area than sub-pixel 110G. In this way, the shape and size of each sub-pixel can be determined independently. For example, the size of a sub-pixel can be reduced to a smaller size if it has a more reliable light-emitting device.

[0340] A pentile array is applied to pixels 124a and 124b shown in Figure 7C. Figure 7C shows an example in which pixels 124a having sub-pixels 110R and 110G and pixels 124b having sub-pixels 110G and 110B are arranged alternately.

[0341] Pixels 124a and 124b shown in Figures 7D to 7F utilize a delta array. Pixel 124a has two subpixels (subpixels 110R and 110G) in the top row (1st row) and one subpixel (subpixel 110B) in the bottom row (2nd row). Pixel 124b has one subpixel (subpixel 110B) in the top row (1st row) and two subpixels (subpixels 110R and 110G) in the bottom row (2nd row).

[0342] Figure 7D shows an example where each subpixel has a roughly square top shape with rounded corners, Figure 7E shows an example where each subpixel has a circular top shape, and Figure 7F shows an example where each subpixel has a roughly hexagonal top shape with rounded corners.

[0343] In Figure 7F, each subpixel is located inside a densely arranged hexagonal region. When focusing on one subpixel, it is arranged so that it is surrounded by six other subpixels. Furthermore, subpixels that emit light of the same color are not adjacent to each other. For example, when focusing on subpixel 110R, three subpixels 110G and three subpixels 110B are arranged alternately around it.

[0344] Figure 7G shows an example where the subpixels of each color are arranged in a zigzag pattern. Specifically, in a top view, the upper edges of two subpixels aligned in the row direction (for example, subpixel 110R and subpixel 110G, or subpixel 110G and subpixel 110B) are offset.

[0345] In each pixel shown in Figures 7A to 7G, it is preferable, for example, that sub-pixel 110R emits red light, sub-pixel 110G emits green light, and sub-pixel 110B emits blue light. However, the configuration of the sub-pixels is not limited to this, and the colors emitted by the sub-pixels and their order can be determined as appropriate. For example, sub-pixel 110G may emit red light, and sub-pixel 110R may emit green light.

[0346] In photolithography, the finer the pattern being processed, the more significant the effects of light diffraction become. This compromises the fidelity of transferring the photomask pattern through exposure, making it difficult to process the resist mask into the desired shape. Therefore, even if the photomask pattern is rectangular, patterns with rounded corners are likely to form. Consequently, the top surface shape of subpixels may be a polygon with rounded corners, an ellipse, or a circle.

[0347] 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 organic compound layer material and the curing temperature of the resist material, the curing of the resist film may be insufficient. A resist film that is not sufficiently cured may take a shape that deviates from the desired shape during processing. As a result, the top surface shape of the organic compound layer may become a polygon with rounded corners, an ellipse, or a circle. For example, if an attempt is made to form a resist mask with a square top surface, a resist mask with a circular top surface may be formed, resulting in a circular top surface shape for the organic compound layer.

[0348] Furthermore, in order to achieve the desired shape of the upper surface of the organic compound layer, a technique (OPC (Optical Proximity Correction) technique) may be used to pre-correct the mask pattern so that the design pattern and the transferred pattern match. Specifically, in the OPC technique, for example, a correction pattern is added to the corners of the shape on the mask pattern.

[0349] As shown in Figures 8A to 8I, a pixel can be configured to have four types of subpixels.

[0350] The pixels 178 shown in Figures 8A to 8C are arranged in a stripe pattern.

[0351] Figure 8A shows an example where each subpixel has a rectangular top surface shape, Figure 8B shows an example where each subpixel has a top surface shape formed by connecting two semicircles and a rectangle, and Figure 8C shows an example where each subpixel has an elliptical top surface shape.

[0352] The pixels 178 shown in Figures 8D to 8F are subjected to a matrix arrangement.

[0353] Figure 8D shows an example where each subpixel has a square top surface shape, Figure 8E shows an example where each subpixel has a roughly square top surface shape with rounded corners, and Figure 8F shows an example where each subpixel has a circular top surface shape.

[0354] Figures 8G and 8H show an example where one pixel 178 is composed of two rows and three columns.

[0355] Pixel 178, shown in Figure 8G, has three subpixels (subpixel 110R, subpixel 110G, and subpixel 110B) in the top row (1st row) and one subpixel (subpixel 110W) in the bottom row (2nd row). In other words, pixel 178 has subpixel 110R in the left column (1st column), subpixel 110G in the middle column (2nd column), subpixel 110B in the right column (3rd column), and subpixel 110W extending across these three columns.

[0356] Pixel 178, shown in Figure 8H, has three sub-pixels (sub-pixels 110R, 110G, and 110B) in the top row (1st row) and three sub-pixels 110W in the bottom row (2nd row). In other words, pixel 178 has sub-pixels 110R and 110W in the left column (1st column), sub-pixels 110G and 110W in the middle column (2nd column), and sub-pixels 110B and 110W in the right column (3rd column). As shown in Figure 8H, by aligning the arrangement of sub-pixels in the top row and the bottom row, it becomes possible to efficiently remove dust that may be generated during the manufacturing process, for example. Therefore, a light-emitting device with high display quality can be provided.

[0357] In the pixel 178 shown in Figures 8G and 8H, the layout of sub-pixels 110R, 110G, and 110B is in a stripe arrangement, which improves the display quality.

[0358] Figure 8I shows an example where one pixel 178 is composed of 3 rows and 2 columns.

[0359] Pixel 178, shown in Figure 8I, has a sub-pixel 110R in the top row (1st row), a sub-pixel 110G in the middle row (2nd row), a sub-pixel 110B spanning from the 1st to the 2nd row, and one sub-pixel (sub-pixel 110W) in the bottom row (3rd row). In other words, pixel 178 has sub-pixels 110R and 110G in the left column (1st column), a sub-pixel 110B in the right column (2nd column), and a sub-pixel 110W spanning these two columns.

[0360] In the pixel 178 shown in Figure 8I, the layout of sub-pixels 110R, 110G, and 110B is a so-called S-stripe arrangement, which improves the display quality.

[0361] The pixel 178 shown in Figures 8A to 8I is composed of four subpixels: subpixel 110R, subpixel 110G, subpixel 110B, and subpixel 110W. For example, subpixel 110R may be a subpixel that emits red light, subpixel 110G may be a subpixel that emits green light, subpixel 110B may be a subpixel that emits blue light, and subpixel 110W may be a subpixel that emits white light. At least one of 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.

[0362] As described above, the light-emitting device according to one aspect of the present invention can be configured to apply various layouts to pixels that consist of subpixels having light-emitting devices.

[0363] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be appropriately combined.

[0364] (Embodiment 6) This embodiment describes a display device according to one aspect of the present invention.

[0365] The display device of this embodiment can be a high-definition display device. Therefore, the display device of this embodiment can be used, for example, as a display unit for information terminals (wearable devices) such as wristwatches and bracelets, as well as as a display unit for wearable devices that can be worn on the head, such as VR devices such as head-mounted displays (HMDs) and AR devices such as glasses.

[0366] Furthermore, the display device of this embodiment can be a high-resolution display device or a large-screen display device. Therefore, the display device of this embodiment can be used in electronic devices with relatively large screens, such as television equipment, desktop or notebook personal computers, computer monitors, digital signage, and large game machines such as pachinko machines, as well as in the display units of digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal information terminals, and audio playback devices.

[0367] [Display Module] Figure 9A shows a perspective view of the display module 280. The display module 280 includes a display device 100A and an FPC 290. Note that the display device included in the display module 280 is not limited to the display device 100A, but may be any of the display devices 100B to 100E described later.

[0368] The display module 280 has substrates 291 and 292. The display module 280 has a display unit 281. The display unit 281 is an area in the display module 280 that displays an image, and is an area in which light from each pixel provided in the pixel unit 284, which will be described later, can be seen.

[0369] Figure 9B shows a schematic perspective view illustrating the configuration of the substrate 291. On the substrate 291, a circuit section 282, a pixel circuit section 283 on the circuit section 282, and a pixel section 284 on the pixel circuit section 283 are stacked. In addition, a terminal section 285 for connecting to the FPC 290 is provided in the portion of the substrate 291 that does not overlap with the pixel section 284. The terminal section 285 and the circuit section 282 are electrically connected by a wiring section 286 composed of multiple wires.

[0370] The pixel section 284 has a plurality of pixels 284a arranged periodically. An enlarged view of one pixel 284a is shown on the right side of Figure 9B. Various configurations described in the previous embodiment can be applied to the pixels 284a.

[0371] The pixel circuit section 283 has a plurality of pixel circuits 283a arranged periodically.

[0372] One pixel circuit 283a is a circuit that controls the driving of multiple devices that a single pixel 284a has.

[0373] The circuit section 282 has circuits for driving each pixel circuit 283a of the pixel circuit section 283. For example, it is preferable to have one or both of a gate line drive circuit and a source line drive circuit. In addition, it may have at least one of the following: an arithmetic circuit, a memory circuit, and a power supply circuit.

[0374] The FPC 290 functions as wiring for supplying video signals or power potential, etc., to the circuit section 282 from an external source. An IC may also be mounted on the FPC 290.

[0375] Since the display module 280 can be configured such that one or both of the pixel circuit section 283 and the circuit section 282 are stacked on the lower side of the pixel section 284, the aperture ratio (effective display area ratio) of the display section 281 can be made extremely high.

[0376] Because such a display module 280 is extremely high-resolution, it can be suitably used in VR devices such as HMDs or AR devices in the form of glasses. For example, even in a configuration where the display part of the display module 280 is viewed through lenses, the display module 280 has an extremely high-resolution display part 281, so even when the display part is magnified with lenses, pixels are not visible, enabling 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 parts.

[0377] [Display device 100A] The display device 100A shown in Figure 10A 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.

[0378] The substrate 301 corresponds to the substrate 291 in Figures 9A and 9B. The transistor 310 is a transistor having a channel formation region in the substrate 301. As the substrate 301, a semiconductor substrate such as a single-crystal silicon substrate can be used. The transistor 310 has 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 of the substrate 301 doped with impurities and functions as a source or drain. The insulating layer 314 is provided covering the side surface of the conductive layer 311.

[0379] Furthermore, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0380] Furthermore, an insulating layer 261 is provided to cover the transistor 310, and a capacitance 240 is provided on the insulating layer 261.

[0381] The capacitor 240 has a conductive layer 241, a conductive layer 245, and an insulating layer 243 located between them. The conductive layer 241 functions as one electrode of the capacitor 240, the conductive layer 245 functions as the other electrode of the capacitor 240, and the insulating layer 243 functions as the dielectric of the capacitor 240.

[0382] The conductive layer 241 is provided on the insulating layer 261 and embedded in the insulating layer 254. The conductive layer 241 is electrically connected to either the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided covering the conductive layer 241. The conductive layer 245 is provided in the region that overlaps with the conductive layer 241 via the insulating layer 243.

[0383] An insulating layer 255 is provided covering the capacitance 240, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. Light-emitting devices 130R, 130G, and 130B are provided on the insulating layer 175. An insulator is provided in the region between adjacent light-emitting devices.

[0384] An insulating layer 156R is provided so as to have a region that overlaps with the side surface of the conductive layer 151R, an insulating layer 156G is provided so as to have a region that overlaps with the side surface of the conductive layer 151G, and an insulating layer 156B is provided so as to have a region that overlaps with the side surface of the conductive layer 151B. Furthermore, a conductive layer 152R is provided so as to cover the conductive layer 151R and the insulating layer 156R, a conductive layer 152G is provided so as to cover the conductive layer 151G and the insulating layer 156G, and a conductive layer 152B is provided so as to cover the conductive layer 151B and the insulating layer 156B. A sacrificial layer 158R is located on the organic compound layer 103R, a sacrificial layer 158G is located on the organic compound layer 103G, and a sacrificial layer 158B is located on the organic compound layer 103B.

[0385] The conductive layers 151R, 151G, and 151B are electrically connected to either the source or drain of the transistor 310 by the insulating layers 243, 255, 174, and plugs 256 embedded in the insulating layer 175, the conductive layer 241 embedded in the insulating layer 254, and plugs 271 embedded in the insulating layer 261. Various conductive materials can be used for the plugs.

[0386] Furthermore, a protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. A substrate 120 is bonded to the protective layer 131 by a resin layer 122. Details of the components from the light-emitting devices 130 to the substrate 120 can be found in Embodiment 4. The substrate 120 corresponds to the substrate 292 in Figure 9A.

[0387] Figure 10B is a modified example of the display device 100A shown in Figure 10A. The display device shown in Figure 10B has a colored layer 132R, a colored layer 132G, and a colored layer 132B, and the light-emitting device 130 has a region that overlaps with one of the colored layers 132R, 132G, and 132B. In the display device shown in Figure 10B, the light-emitting device 130 can emit, for example, white light. Also, 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.

[0388] [Display device 100B] Figure 11 shows a perspective view of the display device 100B, and Figure 12 shows a cross-sectional view of the display device 100C.

[0389] The display device 100B has a configuration in which substrate 352 and substrate 351 are bonded together. In Figure 11, substrate 352 is shown with a dashed line.

[0390] The display device 100B includes a pixel section 177, a connection section 140, a circuit 356, and wiring 355, etc. Figure 11 shows an example in which an IC 354 and an FPC 353 are mounted on the display device 100B. Therefore, the configuration shown in Figure 11 can also be called a display module having a display device 100B, an IC (integrated circuit), and an FPC. Here, a display module is a display device on which a connector such as an FPC is attached to the substrate, or on which an IC is mounted.

[0391] The connection portion 140 is provided on the outside of the pixel portion 177. There may be one or more connection portions 140. The connection portion 140 is electrically connected to the common electrode of the light-emitting device and the conductive layer, and can supply potential to the common electrode.

[0392] For example, a scan line drive circuit can be used as circuit 356.

[0393] The wiring 355 has the function of supplying signals and power to the pixel unit 177 and the circuit 356. These signals and power are input to the wiring 355 from an external source via the FPC 353 or from the IC 354.

[0394] Figure 11 shows an example in which IC 354 is provided on the substrate 351 using the COG (Chip On Glass) method or the COF (Chip On Film) method. IC 354 can be an IC having, for example, a scan line drive circuit or a signal line drive circuit. Note that the display device 100B and the display module may be configured without an IC. Alternatively, the IC may be mounted on the FPC, for example, using the COF method.

[0395] Figure 12 shows an example of a cross-section of the display device 100B in Figure 11, 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, and these are shown as the display device 100C.

[0396] [Display device 100C] The display device 100C shown in Figure 12 has a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light, etc., between the substrate 351 and the substrate 352.

[0397] Details of the light-emitting devices 130R, 130G, and 130B can be found in Embodiment 4.

[0398] Light-emitting device 130R has a conductive layer 224R, a conductive layer 151R on the conductive layer 224R, and a conductive layer 152R on the conductive layer 151R. Light-emitting device 130G has a conductive layer 224G, a conductive layer 151G on the conductive layer 224G, and a conductive layer 152G on the conductive layer 151G. Light-emitting device 130B has a conductive layer 224B, a conductive layer 151B on the conductive layer 224B, and a conductive layer 152B on the conductive layer 151B.

[0399] The conductive layer 224R is connected to the conductive layer 222b of the transistor 205 through an opening provided in the insulating layer 214. The end of the conductive layer 151R is located outside the end of the conductive layer 224R. The insulating layer 156R is provided so as to have a region in contact with the side surface of the conductive layer 151R, and the conductive layer 152R is provided so as to cover the conductive layer 151R and the insulating layer 156R.

[0400] The conductive layers 224G, 151G, 152G, and insulating layer 156G in the light-emitting device 130G, and the conductive layers 224B, 151B, 152B, and insulating layer 156B in the light-emitting device 130B are the same as the conductive layers 224R, 151R, 152R, and insulating layer 156R in the light-emitting device 130R, so a detailed explanation is omitted.

[0401] The conductive layer 224R, conductive layer 224G, and conductive layer 224B have recesses formed to cover the openings provided in the insulating layer 214. Layer 128 is embedded in these recesses.

[0402] Layer 128 has the function of filling and flattening the recesses of conductive layers 224R, 224G, and 224B. Conductive layers 151R, 151G, and 151B are provided on conductive layers 224R, 224G, and 224B and on layer 128, and are electrically connected to conductive layers 224R, 224G, and 224B. Therefore, regions overlapping with the recesses of conductive layers 224R, 224G, and 224B can also be used as light-emitting regions, thereby increasing the aperture ratio of the pixels.

[0403] 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 layer 128 as appropriate. In particular, it is preferable that layer 128 be formed using an insulating material, and especially preferable that it be formed using an organic insulating material. For example, an organic insulating material that can be used for the insulating layer 127 described above can be applied to layer 128.

[0404] A protective layer 131 is provided on the light-emitting devices 130R, 130G, and 130B. The protective layer 131 and the substrate 352 are bonded via an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. A solid sealing structure or a hollow sealing structure can be applied to seal the light-emitting devices 130. In Figure 12, the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, indicating a solid sealing structure. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), indicating a hollow sealing structure. In this case, the adhesive layer 142 may be provided so as not to overlap with the light-emitting devices. Furthermore, the space may be filled with a resin different from the adhesive layer 142, which is provided in a frame shape.

[0405] Figure 12 shows an example in which the connection portion 140 has a conductive layer 224C obtained by processing the same conductive film as conductive layers 224R, 224G, and 224B; a conductive layer 151C obtained by processing the same conductive film as conductive layers 151R, 151G, and 151B; and a conductive layer 152C obtained by processing the same conductive film as conductive layers 152R, 152G, and 152B. Figure 12 also shows an example in which an insulating layer 156C is provided so as to have a region that overlaps with the side surface of conductive layer 151C.

[0406] The display device 100C is a top-emission type. The light emitted by the light-emitting device is emitted towards the substrate 352. It is preferable to use a material with high transmittance to visible light for the substrate 352. The pixel electrodes contain a material that reflects visible light, and the counter electrodes (common electrodes 155) contain a material that transmits visible light.

[0407] On the substrate 351, insulating layers 211, 213, 215, and 214 are provided in this order. A portion of insulating layer 211 functions as a gate insulating layer for each transistor. A portion of insulating layer 213 functions as a gate insulating layer for each transistor. Insulating layer 215 is provided covering the transistors. Insulating layer 214 is provided covering the transistors and functions as a planarization layer. The number of gate insulating layers and insulating layers covering the transistors are not limited and may be a single layer or two or more layers, respectively.

[0408] It is preferable to use an inorganic insulating film as the insulating layer 211, insulating layer 213, and insulating layer 215.

[0409] An organic insulating layer is preferred for the insulating layer 214, which functions as a planarizing layer.

[0410] Transistors 201 and 205 have 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 source and 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.

[0411] A connection portion 204 is provided in the region of substrate 351 where substrate 352 does not overlap. At the connection portion 204, the source electrode or drain electrode of transistor 201 is electrically connected to FPC 353 via conductive layer 166 and connection layer 242. The conductive layer 166 is shown as an example of a laminated structure consisting of a conductive film obtained by processing the same conductive film as conductive layers 224R, 224G, and 224B, a conductive film obtained by processing the same conductive film as conductive layers 151R, 151G, and 151B, and a conductive film obtained by processing the same conductive film as 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 FPC 353 to be electrically connected via the connection layer 242.

[0412] It is preferable to provide a light-shielding layer 157 on the surface of the substrate 352 that faces the substrate 351. The light-shielding layer 157 can be provided between adjacent light-emitting devices, at connection points 140, and in circuits 356, etc. Various optical components can also be arranged on the outside of the substrate 352.

[0413] Materials suitable for use on substrate 120 can be applied to substrate 351 and substrate 352, respectively.

[0414] As the adhesive layer 142, a material that can be used for the resin layer 122 can be applied.

[0415] As the connecting layer 242, an anisotropic conductive film (ACF) or an anisotropic conductive paste (ACP) can be used.

[0416] [Display device 100D] The display device 100D shown in Figure 13 differs from the display device 100C shown in Figure 12 mainly in that it is a bottom-emission type display device.

[0417] The light emitted by the light-emitting device is emitted towards the substrate 351. It is preferable to use a material with high transmittance to visible light for the substrate 351. On the other hand, the light transmittance of the material used for the substrate 352 is not a requirement.

[0418] It is preferable to form a light-shielding layer 317 between the substrate 351 and the transistor 201, and between the substrate 351 and the transistor 205. Figure 13 shows an example in which a light-shielding layer 317 is provided on the substrate 351, an insulating layer 153 is provided on the light-shielding layer 317, and transistors 201, 205, etc. are provided on the insulating layer 153.

[0419] The light-emitting device 130R includes a conductive layer 112R, a conductive layer 126R on the conductive layer 112R, and a conductive layer 129R on the conductive layer 126R.

[0420] The light-emitting device 130B includes a conductive layer 112B, a conductive layer 126B on the conductive layer 112B, and a conductive layer 129B on the conductive layer 126B.

[0421] The conductive layers 112R, 112B, 126R, 126B, 129R, and 129B are made of materials with high transmittance to visible light. It is preferable to use a material that reflects visible light for the second electrode 102.

[0422] Although the light-emitting device 130G is not shown in Figure 13, it is also provided.

[0423] Furthermore, while Figure 13 and other figures show an example where the upper surface of layer 128 has a flat portion, the shape of layer 128 is not particularly limited.

[0424] [Display Device 100D2] The display device 100D2 shown in Figure 14 is an example of a bottom-emission type display device, different from the display device 100D shown in Figure 13. The display device 100D2 differs from the display device 100D in that it has an organic resin layer 180. Note that in the figure, the reference numerals for components that are the same as in Figure 13 may be omitted, and details can be found in the description in Figure 13.

[0425] Furthermore, Figure 14B shows the top view layout of a pixel 178 (pixels 178a and 178b) having sub-pixels 110 (sub-pixels 110R, 110G, 110B, and 110W), and Figure 14C shows the top view of the organic resin layer 180 in the region where sub-pixels 110R and 110G of pixel 178 are formed. The space between the light-shielding layers 317 is the width 110Rw of the light-emitting region of sub-pixel 110R.

[0426] As shown in Figure 14A, the organic resin layer 180 is provided on the insulating layer 214. As shown in the region enclosed by the dashed line in Figure 14A and in Figure 14C, the organic resin layer 180 has curved recesses 181 (recesses 181a and 181b) in at least the region where subpixels are formed. The recesses 181 may also be provided outside the light-emitting region, such as recess 181c. By providing recess 181c, the light emitted in the region overlapping with the light-shielding layer 317 or the light that has traveled to the region overlapping with the light-shielding layer 317 can be refracted and extracted from the light-emitting region, thereby improving the luminous efficiency.

[0427] Multiple recesses 181 may be formed in a matrix. Recesses 181a and 181b may be in contact with each other, or they may have a flat surface between them.

[0428] Furthermore, in Figure 14, the top surface shape of the recess is shown as a hexagon (Figure 14C) and the cross-sectional shape as a semicircle (Figure 14A), but other shapes may be used as needed. For example, the top surface shape of the recess may be a triangle, a quadrilateral (including rectangles and squares), a pentagon or other polygon, a polygon with rounded corners, an ellipse, or a circle.

[0429] As the organic resin layer 180, an insulating layer having an organic material can be used. For example, as the organic resin layer 180, acrylic resin, polyimide resin, epoxy resin, imide resin, polyamide resin, polyimidoamide resin, silicone resin, siloxane resin, benzocyclobutene resin, phenol resin, and precursors of these resins can be used. Alternatively, as the organic resin layer 180, organic materials such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinylpyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used.

[0430] Furthermore, a photosensitive resin can be used as the organic resin layer 180. A photoresist may be used as the photosensitive resin. The photosensitive resin can be a positive-type material or a negative-type material.

[0431] The organic resin layer 180 may contain a material that absorbs visible light. For example, the organic resin layer 180 itself may be composed of a material that absorbs visible light, or the organic resin layer 180 may contain a pigment that absorbs visible light. As the organic resin layer 180, for example, a resin that can be used as a color filter that transmits red, blue, or green light and absorbs other light, or a resin that contains carbon black as a pigment and functions as a black matrix can be used.

[0432] Furthermore, the organic resin layer 180 has a first electrode 101 (first electrode 101R and first electrode 101W), and the first electrode 101 has an organic compound layer 103. The ends of the first electrode 101 and the organic compound layer 103 may be covered with an insulating layer 127.

[0433] Furthermore, the first electrode 101, formed on the organic resin layer 180, similarly has recesses along with the recesses of the organic resin layer 180. Additionally, the organic compound layer 103, formed on the first electrode 101, similarly has recesses along with the recesses of the first electrode 101. Furthermore, the common layer 104, formed on the organic compound layer 103, similarly has recesses along with the recesses of the organic compound layer 103. Furthermore, the second electrode 102, formed on the common layer 104, similarly has recesses along with the recesses of the common layer 104. In other words, the recesses of the organic resin layer 180, the first electrode 101, the organic compound layer 103, the common layer 104, and the second electrode 102 have a structure in which they overlap each other.

[0434] Furthermore, a common layer 104 is provided on the organic compound layer 103 and the insulating layer 127, and a second electrode 102 is provided on the common layer 104. A protective layer 131 is provided on the second electrode 102, and the structure is bonded to the substrate 352 via an adhesive layer 142.

[0435] Although the light-emitting devices 130G and 130B are not shown in Figure 14, they are also provided.

[0436] [Display device 100E] The display device 100E shown in Figure 15 is a modified version of the display device 100C shown in Figure 12, and differs from the display device 100C mainly in that it has a colored layer 132R, a colored layer 132G, and a colored layer 132B.

[0437] In the display device 100E, the light-emitting device 130 has a region that overlaps with one of the colored layers 132R, 132G, and 132B. The colored layers 132R, 132G, and 132B can be provided on the substrate 351 side of the substrate 352. The edges of the colored layer 132R, the edges of the colored layer 132G, and the edges of the colored layer 132B can overlap with the light-shielding layer 157.

[0438] In the display device 100E, the light-emitting device 130 can emit, for example, white light. Also, 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 display device 100E may also be configured to have the colored layers 132R, 132G, and 132B placed between the protective layer 131 and the adhesive layer 142.

[0439] [Display device 100E2] The display device 100E2 shown in Figure 16(A) is a modified example of the display device 100E shown in Figure 15, and has a microlens 182 on the colored layer 132R, the colored layer 132G, and the colored layer 132B. Note that in the figure, the reference numerals for components that are the same as in Figure 15 may be omitted, and details can be found in the description in Figure 15.

[0440] Figure 16B shows the top view layout of a pixel 178 (pixels 178a and 178b) having sub-pixels 110 (sub-pixels 110R, 110G, and 110B), and Figure 16C shows the top view of the microlens 182 in the region where the sub-pixels 110R and 110G of pixel 178 are formed. The region where the common electrode 155 and the organic compound layer 103 are in contact is the width 110Gw of the light-emitting region of sub-pixel 110G.

[0441] The display device 100E2 shown in Figure 14A has a planarization film 143 on a protective layer 131, and a colored layer 132R, a colored layer 132G, and a colored layer 132B on the planarization film 143. A planarization film 144 is provided so as to cover the colored layers 132R, 132G, and 132B. A microlens 182 is provided on the planarization film 144.

[0442] Furthermore, as shown in Figure 16C, the microlenses 182 may be provided for each sub-pixel in the region where the sub-pixels are formed.

[0443] In Figure 16C, the top surface shape of the microlens 182 is shown as a hexagon, but other shapes may be used as needed. For example, the top surface shape of the recess may be a triangle, a quadrilateral (including rectangles and squares), a pentagon, or other polygons, a polygon with rounded corners, an ellipse, or a circle.

[0444] The microlens 182 can be formed using the same material as the organic resin layer 180.

[0445] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be appropriately combined.

[0446] (Embodiment 7) This embodiment describes an electronic device according to one aspect of the present invention.

[0447] The electronic device of this embodiment has a light-emitting device according to one aspect of the present invention in its display unit. The light-emitting device according to one aspect of the present invention is highly reliable and easily capable of high-definition and high-resolution displays. Therefore, it can be used in the display units of various electronic devices.

[0448] Examples of electronic devices include television sets, desktop or notebook personal computers, computer monitors, digital signage, large game machines such as pachinko machines, and other electronic devices with relatively large screens, as well as digital cameras, digital video cameras, digital photo frames, mobile phones, portable game consoles, personal digital assistants, and audio playback devices.

[0449] In particular, since the light-emitting device according to one aspect of the present invention can increase resolution, it can be suitably used in electronic devices having a relatively small display area. Examples of such electronic devices include wristwatch-type and bracelet-type information terminals (wearable devices), as well as wearable devices that can be attached to the head, such as VR devices such as head-mounted displays, AR devices such as glasses, and MR (Mixed Reality) devices.

[0450] A light-emitting device according to one aspect of the present invention preferably has an extremely high resolution such as HD (1280 x 720 pixels), FHD (1920 x 1080 pixels), WQHD (2560 x 1440 pixels), WQXGA (2560 x 1600 pixels), 4K (3840 x 2160 pixels), or 8K (7680 x 4320 pixels). In particular, a resolution of 4K, 8K, or higher is preferred. Furthermore, the pixel density (resolution) of the light-emitting device according to one aspect of the present invention is preferably 100 ppi or more, preferably 300 ppi or more, more preferably 500 ppi or more, more preferably 1000 ppi or more, more preferably 2000 ppi or more, more preferably 3000 ppi or more, more preferably 5000 ppi or more, and even more preferably 7000 ppi or more. By using a light-emitting device having high resolution and / or high detail, it is possible to further enhance the sense of presence and depth. Furthermore, there are no particular limitations on the aspect ratio of the light-emitting device according to one embodiment of the present invention. For example, the light-emitting device can accommodate various aspect ratios such as 1:1 (square), 4:3, 16:9, and 16:10.

[0451] The electronic device of this embodiment may have sensors (including those with functions to measure force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation).

[0452] The electronic device of this embodiment can have a variety of functions. For example, it can have a function to display various information (still images, videos, text images, etc.) on the display unit, a touch panel function, a function to display a calendar, date or time, a function to execute various software (programs), a wireless communication function, a function to read programs or data recorded on a recording medium, and so on.

[0453] Figures 17A to 17D illustrate an example of a wearable device that can be worn on the head. These wearable devices have at least one of the following functions: a function to display AR content, a function to display VR content, a function to display SR (Substantial Reality) content, and a function to display MR content. By having an electronic device that has the function to display at least one of the following content types, such as AR, VR, SR, and MR, it is possible to enhance the user's sense of immersion.

[0454] The electronic device 700A shown in Figure 17A and the electronic device 700B shown in Figure 17B each include a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting units 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0455] A light-emitting device according to one embodiment of the present invention can be applied to the display panel 751. Therefore, a highly reliable electronic device can be made.

[0456] Electronic devices 700A and 700B can project an image displayed on the display panel 751 onto the display area 756 of the optical element 753. Because the optical element 753 is translucent, the user can see the image displayed on the display area superimposed on the transmitted image visible through the optical element 753. Therefore, electronic devices 700A and 700B are electronic devices capable of AR display.

[0457] Electronic devices 700A and 700B may be equipped with cameras capable of capturing images of the area in front of them as imaging units. Furthermore, electronic devices 700A and 700B may each be equipped with acceleration sensors such as gyro sensors to detect the orientation of the user's head and display an image corresponding to that orientation in the display area 756.

[0458] The communications unit has a wireless communication device, which can supply, for example, a video signal. Alternatively, instead of the wireless communication device, or in addition to the wireless communication device, it may be equipped with a connector to which a cable for supplying video signals and power potential can be connected.

[0459] Furthermore, electronic devices 700A and 700B are equipped with batteries that can be charged wirelessly, wired, or both.

[0460] The housing 721 may be equipped with a touch sensor module. The touch sensor module has the function of detecting when the outer surface of the housing 721 is touched. The touch sensor module can detect the user's tap or slide operations and perform various processes. For example, a tap operation can be used to pause or resume the video, and a slide operation can be used to fast forward or rewind. Furthermore, by providing a touch sensor module in each of the two housings 721, the range of operations can be expanded.

[0461] Various types of touch sensors can be used in the touch sensor module. For example, various methods such as capacitive, resistive, infrared, electromagnetic induction, surface acoustic wave, or optical sensors can be employed. In particular, it is preferable to apply capacitive or optical sensors to the touch sensor module.

[0462] When using an optical touch sensor, a photoelectric conversion device (also called a photoelectric conversion element) can be used as the light-receiving device. The active layer of the photoelectric conversion device can be made of either an inorganic semiconductor or an organic semiconductor, or both.

[0463] The electronic device 800A shown in Figure 17C and the electronic device 800B shown in Figure 17D each include a pair of display units 820, a housing 821, a communication unit 822, a pair of mounting units 823, a control unit 824, a pair of imaging units 825, and a pair of lenses 832.

[0464] A light-emitting device according to one embodiment of the present invention can be applied to the display unit 820. Therefore, a highly reliable electronic device can be made.

[0465] The display unit 820 is located inside the housing 821 in a position visible through the lens 832. Furthermore, by displaying different images on a pair of display units 820, a three-dimensional display using parallax can be achieved.

[0466] Electronic devices 800A and 800B can each be described as electronic devices for VR. A user wearing electronic device 800A or electronic device 800B can view the image displayed on the display unit 820 through the lens 832.

[0467] It is preferable that electronic devices 800A and 800B each have a mechanism that allows adjustment of the left and right positions of the lens 832 and the display unit 820 so that they are in the optimal position according to the user's eye position. It is also preferable that they have a mechanism that adjusts the focus by changing the distance between the lens 832 and the display unit 820.

[0468] The attachment portion 823 allows the user to attach the electronic device 800A or 800B to their head. Note that, for example, in Figure 17C, it is illustrated as having a shape similar to the temples (or arms, etc.) of eyeglasses, but it is not limited to this. The attachment portion 823 only needs to be wearable by the user; for example, it may be helmet-shaped or band-shaped.

[0469] The imaging unit 825 has the function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used in the imaging unit 825. In addition, multiple cameras may be provided to accommodate multiple angles of view, such as telephoto and wide-angle.

[0470] Although an example with an imaging unit 825 is shown here, any distance measuring sensor (hereinafter also referred to as a detection unit) capable of measuring the distance to an object can be provided. In other words, the imaging unit 825 is one form of the detection unit. As the detection unit, for example, an image sensor or a distance image sensor such as LiDAR (Light Detection and Ranging) can be used. By using the image obtained by the camera and the image obtained by the distance image sensor, more information can be acquired, enabling more accurate gesture control.

[0471] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone. For example, a configuration having such a vibration mechanism can be applied to one or more of the display unit 820, housing 821, and mounting unit 823. This eliminates the need for separate audio equipment such as headphones, earphones, or speakers, allowing users to enjoy video and audio simply by wearing the electronic device 800A.

[0472] Electronic devices 800A and 800B may each have input terminals. Cables can be connected to the input terminals to supply video signals from video output devices, etc., and power for charging batteries provided in the electronic devices.

[0473] An electronic device according to one aspect of the present invention may have a function for wireless communication with an earphone 750. The earphone 750 has a communication unit (not shown) and has a wireless communication function. The earphone 750 can receive information (e.g., voice data) from the electronic device through its wireless communication function. For example, the electronic device 700A shown in Figure 17A has a function for transmitting information to the earphone 750 through its wireless communication function. Also, for example, the electronic device 800A shown in Figure 17C has a function for transmitting information to the earphone 750 through its wireless communication function.

[0474] Furthermore, the electronic device may have an earphone section. The electronic device 700B shown in Figure 17B has an earphone section 727. For example, the earphone section 727 and the control unit can be connected to each other by a wire. Part of the wiring connecting the earphone section 727 and the control unit may be located inside the housing 721 or the mounting section 723.

[0475] Similarly, the electronic device 800B shown in Figure 17D has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be connected to each other by a wire. Part of the wiring connecting the earphone unit 827 and the control unit 824 may be located inside the housing 821 or the mounting unit 823. Also, the earphone unit 827 and the mounting unit 823 may have magnets. This allows the earphone unit 827 to be fixed to the mounting unit 823 by magnetic force, making storage easier and preferable.

[0476] Furthermore, the electronic device may have an audio output terminal to which earphones or headphones can be connected. The electronic device may also have an audio input terminal and / or an audio input mechanism. For example, a microphone or other sound-collecting device can be used as the audio input mechanism. By having an audio input mechanism, the electronic device may be given the function of a so-called headset.

[0477] Thus, as one embodiment of the present invention, both eyeglass-type (electronic devices 700A and 700B, etc.) and goggle-type (electronic devices 800A and 800B, etc.) are preferred as electronic devices.

[0478] Furthermore, an electronic device according to one aspect of the present invention can transmit information to earphones via wired or wireless means.

[0479] The electronic device 6500 shown in Figure 18A is a portable information terminal that can be used as a smartphone.

[0480] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, and a light source 6508, etc. The display unit 6502 has a touch panel function.

[0481] A light-emitting device according to one embodiment of the present invention can be applied to the display unit 6502. Therefore, a highly reliable electronic device can be made.

[0482] Figure 18B is a schematic cross-sectional view of the housing 6501 including the end on the microphone 6506 side.

[0483] A light-transmitting protective member 6510 is provided on the display side of the housing 6501, and the display panel 6511, optical member 6512, touch sensor panel 6513, printed circuit board 6517, and battery 6518 are arranged in the space enclosed by the housing 6501 and the protective member 6510.

[0484] The protective member 6510 is fixed to the display panel 6511, the optical member 6512, and the touch sensor panel 6513 by an adhesive layer (not shown).

[0485] In the area outside the display unit 6502, a portion of the display panel 6511 is folded back, and the FPC 6515 is connected to this folded portion. IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to terminals provided on the printed circuit board 6517.

[0486] A light-emitting device according to one embodiment of the present invention can be applied to the display panel 6511. This makes it possible to realize an extremely lightweight electronic device. Furthermore, because the display panel 6511 is extremely thin, it is possible to incorporate a large-capacity battery 6518 while keeping the thickness of the electronic device low. In addition, by folding back a part of the display panel 6511 and placing the connection part with the FPC 6515 on the back of the pixel section, an electronic device with a narrow bezel can be realized.

[0487] Figure 18C shows an example of a television system. The television system 7100 has a display unit 7000 incorporated into a housing 7171. Here, the housing 7171 is shown to be supported by a stand 7173.

[0488] A light-emitting device according to one embodiment of the present invention can be applied to the display unit 7000. Therefore, a highly reliable electronic device can be made.

[0489] The television device 7100 shown in Figure 18C can be operated using the operation switches on the housing 7171 and a separate remote control unit 7151. Alternatively, the display unit 7000 may be equipped with a touch sensor, and the television device 7100 can be operated by touching the display unit 7000 with a finger or the like. The remote control unit 7151 may have a display unit that displays information output from the remote control unit 7151. Channels and volume can be controlled and the image displayed on the display unit 7000 can be controlled using the operation keys or touch panel on the remote control unit 7151.

[0490] The television system 7100 is configured to include a receiver and a modem, etc. The receiver can receive general television broadcasts. Furthermore, by connecting to a wired or wireless communication network via the modem, it is possible to perform one-way (from sender to receiver) or two-way (between sender and receiver, or between receivers, etc.) information communication.

[0491] Figure 18D shows an example of a notebook personal computer. The notebook personal computer 7200 has a casing 7211, a keyboard 7212, a pointing device 7213, and an external connection port 7214, etc. A display unit 7000 is incorporated into the casing 7211.

[0492] A light-emitting device according to one embodiment of the present invention can be applied to the display unit 7000. Therefore, a highly reliable electronic device can be made.

[0493] Figures 18E and 18F show examples of digital signage.

[0494] The digital signage 7300 shown in Figure 18E includes a housing 7301, a display unit 7000, and a speaker 7303, etc. Furthermore, it may include LED lamps, operation keys (including a power switch or operation switch), connection terminals, various sensors, a microphone, etc.

[0495] Figure 18F shows a digital signage 7400 mounted on a cylindrical column 7401. The digital signage 7400 has a display unit 7000 that is provided along the curved surface of the column 7401.

[0496] In Figures 18E and 18F, a light-emitting device according to one embodiment of the present invention can be applied to the display unit 7000. Therefore, a highly reliable electronic device can be made.

[0497] The larger the display area 7000, the more information can be provided at once. Furthermore, a larger display area 7000 is more eye-catching, which can, for example, enhance the effectiveness of advertising.

[0498] Applying a touch panel to the display unit 7000 is preferable because it not only allows images or videos to be displayed on the display unit 7000, but also enables intuitive operation by the user. Furthermore, when used for purposes such as providing route information or traffic information, intuitive operation can enhance usability.

[0499] Furthermore, as shown in Figures 18E and 18F, it is preferable that the digital signage 7300 or digital signage 7400 can be linked wirelessly with an information terminal 7311 or information terminal 7411 such as a smartphone owned by the user. For example, the advertising information displayed on the display unit 7000 can be displayed on the screen of the information terminal 7311 or information terminal 7411. Also, the display on the display unit 7000 can be switched by operating the information terminal 7311 or information terminal 7411.

[0500] Furthermore, the digital signage 7300 or digital signage 7400 can be used to run games using the screen of the information terminal 7311 or information terminal 7411 as the control device (controller). This allows an unspecified number of users to participate in and enjoy the game simultaneously.

[0501] The electronic device shown in Figures 19A to 19G includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or operation switch), connection terminals 9006, a sensor 9007 (including a function to measure force, displacement, position, velocity, acceleration, angular velocity, rotational speed, distance, light, liquid, magnetism, temperature, chemical substances, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor, or infrared radiation), a microphone 9008, and the like.

[0502] The electronic devices shown in Figures 19A to 19G have various functions. For example, they may have functions to display various information (still images, videos, text images, etc.) on a display unit, a touch panel function, a function to display a calendar, date or time, a function to control processing by various software (programs), a wireless communication function, a function to read and process programs or data recorded on a recording medium, etc. However, the functions of electronic devices are not limited to these and can have various functions. Electronic devices may have multiple display units. Furthermore, electronic devices may be equipped with a camera, etc., and have functions to capture still images or videos and save them on a recording medium (external or built into the camera), a function to display the captured images on a display unit, etc.

[0503] Details of the electronic equipment shown in Figures 19A to 19G will be explained below.

[0504] Figure 19A is a perspective view showing a personal digital information terminal (PDI) 9171. The PDI 9171 can be used, for example, as a smartphone. The PDI 9171 may also be equipped with a speaker 9003, a connection terminal 9006, or a sensor 9007. Furthermore, the PDI 9171 can display text and image information on multiple surfaces. Figure 19A shows an example where three icons 9050 are displayed. Information 9051, indicated by a dashed rectangle, can also be displayed on other surfaces of the display unit 9001. Examples of information 9051 include notifications of incoming emails, SNS messages, phone calls, etc., the title of emails or SNS messages, the sender's name, date and time, time, battery level, signal strength, etc. Alternatively, icons 9050, etc., may be displayed in the position where the information 9051 is displayed.

[0505] Figure 19B is a perspective view showing a personal digital assistant (PDA) 9172. The PDA 9172 has the function of displaying information on three or more sides of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are displayed on different sides. For example, a user can check information 9053, which is displayed in a position that can be observed from above the PDA 9172, while the PDA 9172 is stored in the breast pocket of their clothing. The user can check the display without taking the PDA 9172 out of their pocket and decide, for example, whether or not to answer a call.

[0506] Figure 19C is a perspective view showing the tablet terminal 9173. The tablet terminal 9173 can run various applications, such as mobile phone calls, email, document viewing and creation, music playback, internet communication, and computer games. The tablet terminal 9173 has a display unit 9001, a camera 9002, a microphone 9008, and a speaker 9003 on the front of the housing 9000. The left side of the housing 9000 has operation keys 9005 as buttons for operation, and the bottom has connection terminals 9006.

[0507] Figure 19D is a perspective view showing a wristwatch-type personal information terminal 9200. The personal information terminal 9200 can be used, for example, as a smartwatch (registered trademark). The display unit 9001 has a curved display surface, allowing it to display information along the curved surface. The personal information terminal 9200 can also make hands-free calls by communicating with, for example, a wireless communication headset. Furthermore, the personal information terminal 9200 can transmit data to other information terminals and be charged via a connection terminal 9006. The charging operation may be performed by wireless power supply.

[0508] Figures 19E to 19G are perspective views showing a foldable portable information terminal 9201. Figure 19E shows the portable information terminal 9201 in an unfolded state, Figure 19G shows it in a folded state, and Figure 19F shows a perspective view of the state in between, transitioning from one of Figures 19E or 19G to the other. The portable information terminal 9201 offers excellent portability in its folded state and excellent readability of the display due to its seamless, wide display area in its unfolded state. The display unit 9001 of the portable information terminal 9201 is supported by three housings 9000 connected by hinges 9055. For example, the display unit 9001 can be bent with a radius of curvature of 0.1 mm to 150 mm.

[0509] This embodiment can be appropriately combined with other embodiments or examples. Furthermore, if multiple configuration examples are shown within a single embodiment in this specification, these configuration examples can be appropriately combined.

[0510] 《Synthesis Example 1》 In this synthesis example, we will describe the synthesis method of 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9'-phenyl-3,3'-bi-9H-carbazole-1,1',2,2',4,4',5,5',6,6',7,7',8,8'-d14 (abbreviated as βNCCP-d21), which is the organic compound of the present invention represented by the structural formula (101) of Embodiment 1. The structure of βNCCP-d21 is shown below.

[0511]

[0512] <Synthesis of 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9'-phenyl-3,3'-bi-9H-carbazole-1,1',2,2',4,4',5,5',6,6',7,7',8,8'-d14 (abbreviation: βNCCP-d21)> In a 200 mL three-necked flask, add 2.5 g (6.7 mmol) of 6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane)-9-(phenyl)-9H-carbazole-1,2,3,4,5,7,8-d7, 2.6 g (6.7 mmol) of 6-bromo-9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9H-carbazole-1,2,3,4,5,7,8-d7, and potassium carbonate (K ２ CO ３) 2.7 g (20 mmol), tri(o-tolyl)phosphine (abbreviation: P(o-tolyl) ３ 62 mg (0.20 mmol) of ) was added, along with 9.7 mL of water, 6.5 mL of ethanol, and 32 mL of toluene. The mixture was degassed by stirring under reduced pressure. After heating the reaction mixture at 60°C, palladium(II) acetate (Pd(OAc)) was added. ２ 25 mg (0.11 mmol) of ) was added and the mixture was stirred at 90°C for 7 hours. After cooling to room temperature and liquid-liquid extraction, the organic layer was dehydrated with magnesium sulfate and filtered by gravity using pleated filter paper. The resulting filtrate was concentrated to obtain 4.4 g of a white solid. This solid was purified by high-performance liquid chromatography to obtain 1.1 g of the target white solid (yield 31%). The synthesis scheme (a-1) of βNCCP-d21 is shown below.

[0513]

[0514] Of the obtained white solid, 0.79 g was purified by sublimation using the train sublimation method. Sublimation purification was performed by heating the solid at a pressure of 3.0 Pa and 315°C for 18 hours. After sublimation purification, 0.42 g of the target white solid was obtained with a recovery rate of 53%.

[0515] The obtained solid １ The numerical data for the H NMR chart is shown below.

[0516] １ 1H NMR (Dichloromethane-d ２ , 500MHz): δ = 8.00-7.20 (br, 5H)

[0517] The molecular weight of the obtained white solid was measured using LC / MS analysis. LC (liquid chromatography) separation was performed using a Thermo Fisher Scientific Ultimate 3000, followed by MS (mass spectrometry) analysis using a Thermo Fisher Scientific Q Exactive.

[0518] As a result, a signal was observed at a mass-to-charge ratio (m / z) of 555 for the calculated mass of the target object (555), indicating that βNCCP-d21 was obtained.

[0519] <Measurement of physical properties> Next, the ultraviolet-visible absorption spectra (hereinafter simply referred to as "absorption spectra") and PL spectra (photoluminescence spectra) of the toluene solution and thin film of βNCCP-d21 were measured.

[0520] A UV-Vis spectrophotometer (V-770DS, JASCO Corporation) was used to measure the absorption spectrum. A spectrofluorometer (FP-8600DS, JASCO Corporation) was used to measure the PL spectrum.

[0521] The absorption spectrum of the toluene solution was calculated by subtracting the absorption spectrum obtained by measuring toluene alone in a quartz cell from the absorption spectrum obtained by measuring βNCCP-d21 in a toluene solution in a quartz cell.

[0522] The absorption and PL spectra of the thin film were obtained by depositing βNCCP-d21 onto a quartz substrate using vacuum deposition, and then sealing the sample with another quartz substrate as the counter substrate. The PL spectrum was measured from the sealed sample, while the absorption spectrum was measured from the sample after the seal was removed and the counter substrate was removed. The absorption spectrum was obtained by subtracting the absorption spectrum of the quartz substrate from the absorption spectrum of the βNCCP-d21 film deposited on the quartz substrate.

[0523] The measurement results for the toluene solution are shown in Figure 20, and the measurement results for the thin film are shown in Figure 21. From the measurement results, a shoulder peak was observed around 353 nm for the toluene solution of βNCCP-d21, and a shoulder peak was observed around 354 nm for the thin film of βNCCP-d21. No absorption bands were observed at wavelengths longer than 430 nm for either the toluene solution or the thin film. From this, it is clear that when βNCCP-d21 is used as a light-emitting element, a decrease in luminescence efficiency due to absorption does not occur at the wavelengths used in displays, and it can be used suitably. In addition, a peak in emission wavelength was observed around 406 nm (excitation wavelength: 303 nm) for the toluene solution of βNCCP-d21, and around 415 nm (excitation wavelength: 343 nm) for the thin film of βNCCP-d21.

[0524] The HOMO and LUMO levels of βNCCP-d21 were calculated based on cyclic voltammetry (CV) measurements. The calculation method is described below.

[0525] An electrochemical analyzer (manufactured by BAS Corporation, model number: ALS Model 600A or 600C) was used as the measuring device. For the CV measurement, anhydrous dimethylformamide (DMF) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 99.5+%, catalog number: 045-32361) was used as the solvent, and tetra-n-butylammonium perchlorate (n-Bu) was used as the supporting electrolyte. ４ NClo ４ The solution was prepared by dissolving (manufactured by Tokyo Chemical Industry Co., Ltd., catalog number: T0836) to a concentration of 100 mmol / L, and then dissolving the target substance to a concentration of 2 mmol / L.

[0526] Furthermore, a platinum electrode (PTE platinum electrode, manufactured by BAS Corporation) was used as the working electrode, a platinum electrode (Pt counter electrode for VC-3 (5cm), manufactured by BAS Corporation) was used as the auxiliary electrode, and Ag / Ag was used as the reference electrode. ＋ Electrodes (RE7 non-aqueous solvent reference electrode, manufactured by BAS Corporation) were used. Measurements were performed at room temperature (20 to 25°C). The scan speed during CV measurement was standardized to 0.1 V / sec, and the oxidation potential Ea [V] and reduction potential Ec [V] relative to the reference electrode were measured. Ea was defined as the intermediate potential of the oxidation-reduction wave, and Ec was defined as the intermediate potential of the reduction-oxidation wave. Here, since the potential energy of the reference electrode used in this embodiment with respect to the vacuum level is known to be -4.94 [eV], the HOMO level [eV] = -4.94 - Ea and the LUMO level [eV] = -4.94 - Ec can be used to determine the HOMO level and LUMO level, respectively.

[0527] Furthermore, CV measurements were repeated 100 times, and the oxidation-reduction wave at the 100th cycle was compared with the oxidation-reduction wave at the 1st cycle to investigate the electrical stability of the compound.

[0528] As a result, the oxidation potential Ea [V] of βNCCP-d21 was measured, and the HOMO level was found to be -5.58 eV. On the other hand, the reduction potential Ec [V] was measured, and the LUMO level was found to be -2.19 eV. Furthermore, when comparing the waveforms after 1 cycle and 100 cycles in repeated oxidation-reduction wave measurements, the peak intensity was maintained at 86% for the Ea measurement and 93% for the Ec measurement, confirming that βNCCP-d21 has good resistance to repeated oxidation and reduction.

[0529] Furthermore, differential scanning calorimetry (DSC measurement) of βNCCP-d21 was performed using a PerkinElmer DSC8500. The differential scanning calorimetry involved heating from -10°C to 350°C at a heating rate of 40°C / min, holding at this temperature for 3 minutes, then cooling to -10°C at a cooling rate of 40°C / min, and holding at this temperature for 3 minutes. This process was repeated twice consecutively. From the DSC measurement results of the second cycle, the glass transition temperature of βNCCP-d21 was observed to be 116°C, while the crystallization temperature and melting point were not detected. This indicates that βNCCP-d21 is a material with high heat resistance and can maintain a stable film quality against heat.

[0530] Furthermore, thermogravimetric-differential thermal analysis (TG-DTA) was performed on βNCCP-d21. A high-vacuum differential thermal balance (Bruker AXS Co., Ltd., TG-DTA2410SA) was used for the measurements. The measurements were performed at atmospheric pressure, with a heating rate of 10°C / min and under a nitrogen gas flow (flow rate of 200 mL / min). Thermogravimetric-differential thermal analysis revealed that the temperature at which the weight obtained from thermogravimetric analysis becomes -5% of the initial weight (decomposition temperature) is 440°C, indicating that the substance has high heat resistance.

[0531] 《Synthesis Example 2》 In this synthesis example, we will describe the synthesis method of 9-(2-naphthyl)-9'-(phenyl-2,3,4,5,6-d5)-3,3'-bi-9H-carbazole-1,1',2,2',4,4',5,5',6,6',7,7',8,8'-d14 (abbreviated as βNCCP-d19), which is the organic compound of the present invention represented by the structural formula (102) of Embodiment 1. The structure of βNCCP-d19 is shown below.

[0532]

[0533] <Step 1: Synthesis of 9-(2-naphthyl)-9H-carbazole-1,2,3,4,5,6,7,8-d8> In a 1 L three-necked flask fitted with a reflux condenser, 10 g (57 mmol) of carbazole-1,2,3,4,5,6,7,8-d8, 13 g (63 mmol) of 2-bromonaphthalene, and 0.47 g (0.57 mmol) of 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl (abbreviated as Sphos) were added. The mixture was degassed under reduced pressure, and the system was then purged with nitrogen. 11 g (0.11 mol) of sodium tert-butoxide and 280 mL of anhydrous xylene were added to the system, and the mixture was further degassed while stirring. This mixture is heated to 60°C, and 0.33 g (0.57 mmol) of bis(dibenzylideneacetone)palladium(0) (abbreviation: Pd(dba)) is added to the mixture. ２ ) was added, and the resulting mixture was heated under reflux with stirring at 120°C for 9 hours. After stirring, the mixture was cooled to room temperature, water was added to the resulting reactants to stop the reaction, and the resulting mixture was separated into an organic layer and an aqueous layer. The obtained aqueous layer was extracted with toluene. The extract solution and the organic layer were washed twice with water and then washed with saturated brine. The organic layer was dried with magnesium sulfate, and the magnesium sulfate was removed by natural filtration. The filtrate obtained by natural filtration was concentrated under reduced pressure and vacuum dried to obtain a black oily substance. The obtained black oily substance was purified by silica gel chromatography (the developing solvent was set to hexane:toluene = 10:1, and changed to hexane:toluene = 7:1 midway through), yielding 17 g of the target white solid in a yield of 96%. The synthesis scheme (b-1) of Step 1 is shown below.

[0534]

[0535] The molecular weight of the white solid obtained in Step 1 was measured using LC / MS analysis. As a result, a signal was observed at a mass-to-charge ratio (m / z) of 302 (proton adduct of 9-(2-naphthyl)-9H-carbazole-1,2,3,4,5,6,7,8-d8) relative to the calculated mass of the target product, 9-(2-naphthyl)-9H-carbazole-1,2,3,4,5,6,7,8-d8, with a mass-to-charge ratio (m / z) of 301. Therefore, it was confirmed that 9-(2-naphthyl)-9H-carbazole-1,2,3,4,5,6,7,8-d8 was obtained by the synthesis in Step 1.

[0536] The obtained solid １ The numerical data for the H NMR chart is shown below.

[0537] １ ¹H NMR (chloroform-d, 500 MHz): δ = 8.07 (d, J = 8.5 Hz, 1H), 8.06 (d, J = 2.0 Hz, 1H), 7.98 (m, 1H), 7.92 (m, 1H), 7.68 (dd, J = 8.5 Hz, J = 2.0 Hz, 1H), 7.59 (m, 2H)

[0538] <Step 2: Synthesis of 6-bromo-9-(2-naphthyl)-9H-carbazole-1,2,3,4,5,7,8-d7> 17 g (56 mmol) of 9-(2-naphthyl)-9H-carbazole-1,2,3,4,5,6,7,8-d8, 50 mL of ethyl acetate, and 250 mL of toluene were added to a 1 L three-necked flask. While stirring the resulting mixture, 10 g (56 mmol) of N-bromosuccinimide (abbreviated as NBS) was gradually added to the mixture, and the mixture was heated and stirred at 40°C for 3 hours, then stirred at room temperature for 16 hours. Water was added to the resulting mixture to stop the reaction, and the organic layer was removed from the system. The organic layer was washed twice with water and then with saturated brine. The organic layer was dried with magnesium sulfate, and the magnesium sulfate was removed by gravity filtration. The filtrate obtained by gravity filtration was concentrated under reduced pressure and vacuum dried to obtain a viscous light brown solid. The obtained viscous light brown solid was recrystallized using toluene and ethanol to obtain a pale white solid. The obtained pale white solid was purified by high-performance liquid chromatography (mobile phase: chloroform) to obtain 10 g of white solid in a yield of 45%. The synthesis scheme (b-2) for step 2 is shown below.

[0539]

[0540] The molecular weight of the white solid obtained in Step 2 was measured using LC / MS analysis. As a result, a signal was observed at a mass-to-charge ratio (m / z) of 378 for the target product, 6-bromo-9-(2-naphthyl)-9H-carbazole-1,2,3,4,5,7,8-d7, with a calculated mass of 378. This clearly indicates that 6-bromo-9-(2-naphthyl)-9H-carbazole-1,2,3,4,5,7,8-d7 was obtained by the synthesis in Step 2.

[0541] The obtained solid １ The numerical data for the H NMR chart is shown below.

[0542] １¹H NMR (chloroform-d, 500 MHz): δ = 8.07 (d, J = 8.5 Hz, 1H), 8.02 (d, J = 1.5 Hz, 1H), 7.98 (m, 1H), 7.91 (m, 1H), 7.63 (dd, J = 8.5 Hz, J = 2.0 Hz, 1H), 7.60 (m, 2H)

[0543] <Step 3: Synthesis of 9-(2-naphthyl)-9'-(phenyl-2,3,4,5,6-d5)-3,3'-bi-9H-carbazole-1,1',2,2',4,4',5,5',6,6',7,7',8,8'-d14 (abbreviation: βNCCP-d19)> In a 200 mL three-necked flask fitted with a reflux tubing, 4.1 g (11 mmol) of 9-(phenyl-2,3,4,5,6-d5)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole-1,2,3,4,5,7,8-d7, 4.1 g (11 mmol) of 6-bromo-9-(2-naphthyl)-9H-carbazole-1,2,3,4,5,7,8-d7, and 66 mg (0.22 mmol) of tri(o-tolyl)phosphine (abbreviation: P(o-tolyl) ３ ) and 3.0 g (22 mmol) of potassium carbonate and (K ２ CO ３ ), 50 mL of toluene, 12 mL of ethanol, and 11 mL of water were added and mixed. After degassing the mixture under reduced pressure, the system was purged with nitrogen. This mixture was heated at 60°C, and 24 mg (0.11 mmol) of palladium(II) acetate (abbreviation: Pd(OAc)) was added to the mixture. ２) was added, and the resulting mixture was heated under reflux at 90°C for 7 hours with stirring. After stirring, the mixture was cooled to room temperature, and water was added to the resulting reactants to stop the reaction. The resulting mixture was separated into an organic layer and an aqueous layer. The obtained aqueous layer was extracted with toluene. The extract and the organic layer were washed twice with water and then with saturated brine. The organic layer was dried with magnesium sulfate, and the magnesium sulfate was removed by natural filtration. The filtrate obtained by natural filtration was concentrated under reduced pressure and vacuum dried to obtain a brown solid. The obtained brown solid was purified by silica gel chromatography (the developing solvent was set to hexane:toluene = 3:1, and changed to hexane:toluene = 2:1 midway through), and then purified by high-performance liquid chromatography (mobile phase: chloroform) to obtain 4.0 g of the target white solid in a yield of 67%. The synthesis scheme (b-3) for βNCCP-d19 is shown below.

[0544]

[0545] Of the obtained solids, 2.8 g was purified by sublimation using the train sublimation method. In the sublimation purification, the solid was heated for 26 hours at temperatures of 290°C and 275°C under a pressure of 2.4 Pa while flowing argon at 15 mL / min, and the precipitated solid at the point heated to 185°C was collected. As a result, 1.7 g of the target white solid was obtained with a recovery rate of 60%.

[0546] The molecular weight of the white solid obtained in Step 3 was measured using LC / MS analysis. As a result, a signal was observed at a mass-to-charge ratio (m / z) of 553, corresponding to the calculated mass of the target product, βNCCP-d19, which was 553. This clearly indicated that βNCCP-d19 was obtained through the synthesis in Step 3.

[0547] The obtained solid １ The numerical data for the H NMR chart is shown below.

[0548] １ 1H NMR (Dichloromethane-d ２ , 500MHz): δ = 8.15-8.13 (m, 2H), 8.02 (m, 1H), 7.97 (m, 1H), 7.76 (dd, J = 8.5Hz, J = 2.0Hz, 1H), 7.63-7.61 (m, 2H)

[0549] In addition, １ In the 1H NMR measurement, the peaks with small area ratios around δ = 7.66, 7.51, 7.45, and 7.35 are peaks that originate from the light hydrogen that remained undeuterated in the material used in step 3.

[0550] 《Synthesis Example 3》 In this synthesis example, we will describe the synthesis method of 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9'-phenyl-3,3'-bi-9H-carbazole-1,2,4,5,6,7,8-d7 (abbreviation: βNCCP-d14-02), which is the organic compound of the present invention represented by the structural formula (103) of Embodiment 1. The structure of βNCCP-d14-02 is shown below.

[0551]

[0552] <Synthesis of 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9'-phenyl-3,3'-bi-9H-carbazole-1,2,4,5,6,7,8-d7 (abbreviation: βNCCP-d14-02)> In a 200 mL three-necked flask, combine 1.5 g (5.3 mmol) of 9-phenyl-9H-carbazole-3-boronic acid, 2.0 g (5.3 mmol) of 6-bromo-9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9H-carbazole-1,2,3,4,5,7,8-d7, and potassium carbonate (K ２ CO ３ ) 2.3 g (17 mmol), tri(o-tolyl)phosphine (abbreviation: P(o-tolyl) ３ 46 mg (0.15 mmol) of ) was added, along with 7.5 mL of water, 5.4 mL of ethanol, and 26 mL of toluene. The mixture was degassed by stirring under reduced pressure. After heating the reaction mixture at 60°C, palladium(II) acetate (Pd(OAc)) was added. ２ ) was added at a dose of 14 mg (62 μmol) and stirred at 90°C for 3 hours. After the predetermined time had elapsed, the reaction mixture was heated at 60°C, and then 57 mg (0.14 mmol) of dicyclohexyl(2',6'-dimethoxy-[1,1'-biphenyl]-2-yl)phosphine and palladium(II) acetate (Pd(OAc)) were added. ２25 mg (0.11 mmol) of ) was added and the mixture was stirred at 90°C for 7 hours. After cooling to room temperature, the organic layer was dehydrated with magnesium sulfate and filtered by suction. The resulting filtrate was concentrated to obtain 3.4 g of a white solid. This solid was purified by high-performance liquid chromatography to obtain 3.0 g of the target white solid. This solid was sublimated by train sublimation to obtain 1.0 g of the target white solid (yield 35%). Sublimation purification was performed at a pressure of 5.0 × 10⁻⁶ −２ The solid was heated at Pa, 290°C for 20 hours. The synthesis scheme (c-1) for βNCCP-d14-02 is shown below.

[0553]

[0554] The obtained solid １ The numerical data for the H NMR chart is shown below.

[0555] １ 1H NMR (Dichloromethane-d ２ , 500MHz): δ = 8.50 (br, 1H), 8.24 (d, J = 8.0Hz, 1H), 7.81 (d, J = 8.0, 1H), 7.6 7-7.62 (m, 4H), 7.55-7.45 (m, 2H), 7.45-7.40 (m, 2H), 7.31 (t, J=7.0Hz, 1H)

[0556] The molecular weight of the obtained white solid was measured using LC / MS analysis. As a result, a signal was observed at a mass-to-charge ratio (m / z) of 548, relative to the calculated mass of the target substance of 548, indicating that βNCCP-d14-02 was obtained.

[0557] 《Synthesis Example 4》 In this synthesis example, we will describe the synthesis method of 9-(2-naphthyl)-9'-(phenyl-2,3,4,5,6-d5)-3,3'-bi-9H-carbazole-1',2',4',5',6',7',8'-d7 (abbreviated as βNCCP-d12), which is the organic compound of the present invention represented by the structural formula (104) of Embodiment 1. The structure of βNCCP-d12 is shown below.

[0558]

[0559] <Synthesis of 9-(2-naphthyl)-9'-(phenyl-2,3,4,5,6-d5)-3,3'-bi-9H-carbazole-1',2',4',5',6',7',8'-d7 (abbreviation: βNCCP-d12)> 1.5 g (4.3 mmol) of 6-bromo-9-(phenyl-2,3,4,5,6-d5)-9H-carbazole (1,2,4,5,6,7,8-d7) and 1.5 g (4.3 mmol) of 3-bromo-9-(2-naphthyl)-9H-carbazole are added to a 200 mL three-necked flask. ２ CO ３ ) 1.8 g (13 mmol), tri(o-tolyl)phosphine (abbreviation: P(o-tolyl) ３ 26 mg (85 μmol) of ) was added, along with 2.0 mL of water, 4 mL of ethanol, and 22 mL of toluene. The mixture was degassed by stirring under reduced pressure. After heating the reaction mixture to 60°C, palladium(II) acetate (Pd(OAc)) was added. ２ ) 26 mg (0.12 mmol) was added and stirred at 90°C for 7 hours. After the predetermined time had elapsed, the reaction mixture was heated at 60°C and tri(o-tolyl)phosphine (abbreviation: P(o-tolyl) ３ ) 47 mg (0.15 mmol), palladium(II) acetate (Pd(OAc) ２ 23 mg (0.10 mmol) of ) was added and the mixture was stirred at 90°C for 7 hours. After cooling to room temperature and liquid-liquid extraction, the organic layer was dehydrated with magnesium sulfate and filtered using pleated filter paper. The resulting filtrate was concentrated to obtain 2.5 g of an ochre solid. This solid was purified by silica gel chromatography (eluent: toluene) to obtain 2.1 g of a pale yellow solid. This solid was purified by high-performance liquid chromatography to obtain 1.6 g of the target product as a pale yellow solid (yield 66%). The synthesis scheme (d-1) of βNCCP-d12 is shown below.

[0560]

[0561] Of the obtained white solid, 0.79 g was purified by sublimation using the train sublimation method. Sublimation purification was performed at a pressure of 3.3 × 10⁻⁶. −２ The solid was heated at Pa, 295°C for 7 hours. After sublimation purification, 0.56 g of the target product was obtained as a white solid with a recovery rate of 70%.

[0562] The obtained solid １ The numerical data for the H NMR chart is shown below.

[0563] １ 1H NMR (Dichloromethane-d ２ , 500MHz): δ = 8.52 (d, J = 1.0Hz, 1H), 8.27 (d, J = 8.0Hz, 1H), 8.12 ( d, J=8.5Hz, 2H), 8.01-7.95(m, 2H), 7.82(dd, J=8.0Hz, J=1.5Hz, 1 H), 7.73 (dd, J = 9.0 Hz, J = 2.0 Hz, 1H), 7.61-7.57 (m, 3H), 7.51 (d, J = 8.5Hz, 1H), 7.46-7.42 (m, 1H), 7.33 (td, J = 7.5Hz, J = 1.0Hz, 1H)

[0564] The molecular weight of the obtained white solid was measured using LC / MS analysis. As a result, a signal was observed at a mass-to-charge ratio (m / z) of 546 relative to the calculated mass of the target substance (546), indicating that βNCCP-d12 was obtained.

[0565] 《Synthesis Example 5》 In this synthesis example, we will describe the synthesis method of 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole-1,2,4,5,6,7,8-d7 (abbreviation: βNCCP-d7-02), which is the organic compound of the present invention represented by the structural formula (105) of Embodiment 1. The structure of βNCCP-d7-02 is shown below.

[0566]

[0567] <Synthesis of 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole-1,2,4,5,6,7,8-d7 (abbreviation: βNCCP-d7-02)> In a 200 mL three-necked flask, combine 1.5 g (5.3 mmol) of 9-phenylcarbazole-3-boronic acid, 2.0 g (5.3 mmol) of 6-bromo-9-(2-naphthyl)-9H-carbazole-1,2,3,4,5,7,8-d7, and potassium carbonate (K ２ CO ３ ) 2.2 g (16 mmol), tri(o-tolyl)phosphine (abbreviation: P(o-tolyl) ３45 mg (0.15 mmol) of ) was added, along with 8.2 mL of water, 5 mL of ethanol, and 26 mL of toluene. The mixture was degassed by stirring under reduced pressure. After heating the reaction mixture to 90°C, palladium(II) acetate (abbreviation: Pd(OAc)) was added. ２ 20 mg (89 μmol) of ) was added and the mixture was stirred at 90°C for 7 hours. After cooling to room temperature and liquid-liquid extraction, the organic layer was dehydrated with magnesium sulfate and filtered by suction through Celite (Fujifilm Wako Pure Chemical Industries, Ltd., catalog number: 537-02305). The resulting filtrate was concentrated to obtain 3.2 g of a white solid. This solid was purified by high-performance liquid chromatography to obtain 2.7 g of the target product as a white solid (yield 94%). The synthesis scheme (e-1) of βNCCP-d7-02 is shown below.

[0568]

[0569] Of the obtained white solid, 2.3 g was purified by sublimation using the train sublimation method. Sublimation purification was performed at a pressure of 1.9 × 10⁻⁶. −２ The solid was heated at Pa, 300°C for 2 hours. After sublimation purification, 1.4 g of the target product was obtained as a white solid with a recovery rate of 61%.

[0570] The obtained solid １ The numerical data for the H NMR chart is shown below.

[0571] １ 1H NMR (Dichloromethane-d ２ , 500MHz): δ = 8.50 (br, 1H), 8.24 (d, J = 7.0Hz, 1H), 8.12 (d, J = 8.0Hz, 2H), 8.01-7.95 (m, 2H), 7.81 ( br, 1H), 7.74 (dd, J=8.5Hz, J=2.5Hz, 1H), 7.67-7.57 (m, 6H), 7.55-7.41 (m, 4H), 7.35-7.27 (m, 1H)

[0572] The molecular weight of the obtained white solid was measured using LC / MS analysis. As a result, a signal was observed at a mass-to-charge ratio (m / z) of 541 relative to the calculated mass of the target substance (541), indicating that βNCCP-d7-02 was obtained.

[0573] 《Synthesis Example 6》 In this synthesis example, we will describe the synthesis method of 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP-d7), which is the organic compound of the present invention represented by the structural formula (106) of Embodiment 1. The structure of βNCCP-d7 is shown below.

[0574]

[0575] <Synthesis of 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP-d7)> 5.7 g (14 mmol) of 9-phenyl-3,3'-bi-9H-carbazole, 3.0 g (14 mmol) of 2-bromonaphthalene-1,3,4,5,6,7,8-d7, and tripotassium phosphate (abbreviation: K) are added to a 200 mL three-necked flask. ３ PO ４ 6.0 g (28 mmol) of ) was added, along with 0.35 mL (2.9 mmol) of 1,2-cyclohexanediamine and 60 mL of anhydrous 1,4-dioxane. The mixture was degassed by stirring under reduced pressure. After heating the reaction mixture at 90°C, 0.32 g (1.7 mmol) of copper iodide was added, and the mixture was stirred at 120°C for 7 hours. After the specified time, 0.93 mg (4.3 mmol) of 2-bromonaphthalene-d7 and 0.29 g (1.5 mmol) of copper iodide were added, and the mixture was stirred at 120°C for 4 hours. After air cooling to room temperature, water was added, and the mixture was extracted with dichloromethane. After liquid-liquid separation, the organic layer was dehydrated with magnesium sulfate and filtered by suction through Celite (Fujifilm Wako Pure Chemical Industries, Ltd., catalog number: 537-02305). The obtained filtrate was concentrated and purified by silica gel column chromatography (developing solvent: hexane / dichloromethane = gradually changed from 3 / 1 to 2 / 1). Thin-layer chromatography (developing solvent: hexane:ethyl acetate = 5:1) was performed. ｆ By concentrating the component with a concentration of 0.54, 5.3 g of a white solid was obtained. This solid was purified by high-performance liquid chromatography to obtain 3.9 g of the target white solid (yield 51%). The synthesis scheme (f-1) of βNCCP-d7 is shown below.

[0576]

[0577] Of the obtained white solid, 2.0 g was purified by sublimation using the train sublimation method. Sublimation purification was performed at a pressure of 1.3 × 10⁻⁶. −２ The solid was heated at Pa, 300°C for 15 hours. After sublimation purification, 1.2 g of the target product was obtained as a white solid with a recovery rate of 59%.

[0578] The obtained solid １ The numerical data for the H NMR chart is shown below.

[0579] １ 1H NMR (Dichloromethane-d ２ , 500MHz): δ = 8.51 (d, J = 8.5Hz, 2H), 8.27 (d, J = 8.0Hz, 1H), 8.24 (d, J = 8.0Hz, 1H), 7.81 (d, J = 8.5Hz, 2 H), 7.67-7.61 (m, 4H), 7.58 (d, J=8.5Hz, 1H), 7.53-7.48 (m, 3H), 7.46-7.41 (m, 3H), 7.35-7.29 (m, 2H)

[0580] The molecular weight of the obtained white solid was measured using LC / MS analysis. As a result, a signal was observed at a mass-to-charge ratio (m / z) of 541 relative to the calculated mass of the target substance (541), indicating that βNCCP-d7 was obtained.

[0581] In this embodiment, a light-emitting device 1 (light-emitting device 1A to light-emitting device 1H) according to one aspect of the present invention was fabricated. In addition, a comparative light-emitting device 1 (comparative light-emitting device 1a to comparative light-emitting device 1h) was fabricated and its characteristics were compared.

[0582] The structural formulas of the organic compounds used in common to light-emitting device 1 and comparative light-emitting device 1 are shown below.

[0583]

[0584] Furthermore, the structural formulas of the organic compounds used in light-emitting devices 1A to 1H and comparative light-emitting device 1 are shown below.

[0585]

[0586] As shown in Figure 22, each device has a structure in which a hole injection layer 811, a hole transport layer 812, a light-emitting layer 813, an electron transport layer 814, and an electron injection layer 815 are sequentially stacked on a first electrode 801 formed on a glass substrate 800, and a second electrode 802 is stacked on the electron injection layer 815.

[0587] <Method for fabricating the light-emitting device 1A> A first electrode 801 was formed on a glass substrate 800 by sputtering an indium tin oxide (ITSO) film containing silicon oxide to a thickness of 70 nm. The electrode area was 4 mm². ２ The dimensions were set to (2 mm x 2 mm).

[0588] Next, as a pretreatment for forming the light-emitting device on the substrate, the substrate surface was washed with water and fired at 200°C for 1 hour. After that, 1 × 10 −４ A substrate was introduced into a vacuum deposition apparatus where the internal pressure was reduced to approximately Pa, and vacuum firing was performed at 170°C for 30 minutes in the heating chamber of the vacuum deposition apparatus. After that, it was allowed to cool naturally for 45 minutes.

[0589] Next, the substrate on which the first electrode 801 is formed is fixed to a substrate holder provided in a vacuum deposition apparatus so that the surface on which the first electrode 801 is formed faces downwards. N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-dimethyl-9H-fluoren-2-amine (abbreviated as PCBBiF) and an electron acceptor material (OCHD-003) with a molecular weight of 672 and containing fluorine are co-deposited on the first electrode for 10 nm in a ratio of PCBBiF:OCHD-003 = 1:0.03 (by weight) to form a hole injection layer 811.

[0590] Next, PCBiF was deposited onto the hole injection layer 811 using a resistive heating deposition method to a thickness of 50 nm to form a hole transport layer 812.

[0591] Next, 8-(p-terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofl[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm), 9-(2-naphthyl)-9'-(phenyl-2,3,4,5,6-d5)-3,3'-bi-9H-carbazole (abbreviation: βNCCP-d5), and tris{2-[5-(methyl-d3)-4-phenyl-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: Ir(5m4dppy-d)) are deposited onto the hole transport layer 812 by a resistive heating deposition method. ３ ) ３ ) and 8mpTP-4mDBtPBfpm:βNCCP-d5:Ir(5m4dppy-d ３ ) ３ A light-emitting layer 813 was formed by co-depositing in a weight ratio of 0.50:0.50:0.10 to a film thickness of 40 nm.

[0592] Next, 2-{3-[3-(N-phenyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}dibenzo[f,h]quinoxaline (abbreviated as 2mPCCzPDBq) was deposited onto the light-emitting layer 813 to a thickness of 10 nm, and then 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviated as mPPhen2P) was co-deposited onto the light-emitting layer 813 to a thickness of 20 nm to form the electron transport layer 814.

[0593] Next, lithium fluoride (LiF) was deposited onto the electron transport layer 814 to a thickness of 1 nm to form an electron injection layer 815.

[0594] Next, a second electrode was formed by depositing aluminum (Al) onto the electron injection layer to a thickness of 200 nm.

[0595] <Method for Fabricating Light-Emitting Device 1B> The method for fabricating light-emitting device 1B is described below. Light-emitting device 1B differs from light-emitting device 1A in the configuration of the light-emitting layer 813. However, the other components were fabricated in the same manner as light-emitting device 1A.

[0596] In other words, the light-emitting device 1B is deposited on the hole transport layer 812 by a resistive heating deposition method using 8mpTP-4mDBtPBfpm, 9-(2-naphthyl-1,3,4,5,6,7,8-d7)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: βNCCP-d7), and Ir(5m4dppy-d ３ ) ３ And, 8mpTP-4mDBtPBfpm:βNCCP-d7:Ir(5m4dppy-d ３ ) ３ A co-deposited layer 813 was formed using a weight ratio of 0.50:0.50:0.10 to achieve a film thickness of 40 nm.

[0597] <Method for Fabricating Light-Emitting Device 1C> The method for fabricating light-emitting device 1C is described below. Light-emitting device 1C differs from light-emitting device 1A in the configuration of the light-emitting layer 813. However, the other components were fabricated in the same manner as light-emitting device 1A.

[0598] In other words, the light-emitting device 1C is deposited on the hole transport layer 812 by a resistive heating deposition method using 8mpTP-4mDBtPBfpm, 9-(2-naphthyl)-9'-phenyl-3,3'-bi-9H-carbazole-1,2,4,5,6,7,8-d7 ...

Claims

1. A light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound and a light-emitting substance, wherein the first organic compound has deuterium in a substructure that contributes significantly to the lowest triplet excited state.

2. A light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has deuterium in a substructure that contributes largely to the lowest triplet excited state and in a substructure that contributes largely to the lowest singlet excited state.

3. A light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has deuterium in a substructure that contributes greatly to the lowest triplet excited state, the second organic compound has deuterium in a substructure that contributes greatly to the lowest triplet excited state, and the difference between the lowest triplet excited levels of the first organic compound and the second organic compound is 0.20 eV or less.

4. A light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has deuterium in a substructure that contributes greatly to the lowest triplet excited state, the second organic compound has deuterium in a substructure that contributes greatly to the lowest triplet excited state and a substructure that contributes greatly to the lowest singlet excited state, and the difference between the lowest triplet excited level of the first organic compound and the lowest triplet excited level of the second organic compound is 0.20 eV or less.

5. A light-emitting device having a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, the light-emitting layer has a first organic compound, a second organic compound, and a light-emitting substance, the first organic compound has deuterium in a partial structure that largely contributes to the lowest triplet excited state, the second organic compound is an organic compound represented by the general formula (G1), and the difference in the lowest triplet excitation levels of the first organic compound and the second organic compound is 0.20 eV or less. (In the general formula (G1), Ar １ and Ar ２ each independently represent an aryl group having 6 to 30 carbon atoms that forms a substituted or unsubstituted ring, R １ to R ７ and R １１ to R １７ each independently represent hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms, and at least one of the hydrogens of Ar １ , the hydrogens of Ar ２ , R １ to R ７ , R １１ to R １７ is deuterium.) 6. A light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has a substructure that contributes significantly to the lowest triplet excited state, the second organic compound is an organic compound represented by general formula (G2), and the difference between the lowest triplet excited levels of the first organic compound and the second organic compound is 0.20 eV or less. (In general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ Each independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms, R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ At least one of them is deuterium.

7. A light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has deuterium in a substructure that contributes significantly to the lowest triplet excited state, the second organic compound is an organic compound represented by general formula (G3), and the difference between the lowest triplet excited levels of the first organic compound and the second organic compound is 0.20 eV or less. (In general formula (G3), Ar １１ and Ar １２ Each of these is a group that can be independently represented by any one of the general formulas (Ar-1) to (Ar-4), and Ar １１ and Ar １２ They have the same fused ring, R ４１ ~R ５４ Each of these independently represents hydrogen (including deuterium), and the general formula (G3) has at least two or more deuterium atoms. (In general formulas (Ar-1) to (Ar-4), R ６１ ~R ６７ , R ７１ ~R ７９ , R ８１ ~R ８９ , and R ９１ ~R １０１ Each of these independently represents hydrogen (including deuterium) or an alkyl group having 1 to 6 carbon atoms. In general formulas (Ar-1) to (Ar-4), the asterisk (*) indicates a bond with general formula (G3).

8. A light-emitting device comprising a first electrode, a second electrode, and a light-emitting layer, wherein the light-emitting layer is located between the first electrode and the second electrode, and the light-emitting layer comprises a first organic compound, a second organic compound, and a light-emitting substance, wherein the first organic compound has deuterium in a substructure that contributes significantly to the lowest triplet excited state, the second organic compound is one of the organic compounds represented by structural formula (101) to structural formula (106), and the difference between the lowest triplet excited levels of the first organic compound and the second organic compound is 0.20 eV or less.

9. Compounds represented by the general formula (G2). (In general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Also, R １ ~R ７ And R １１ ~R １７ At least one of the following, and R ２１ ~R ２７ At least one of them is deuterium, R ２８ ~R ３２ At least one of them is light hydrogen.

10. Compounds represented by the general formula (G2). (In general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Also, R １ ~R ７ And R １１ ~R １７ At least one of the following, and R ２８ ~R ３２ At least one of them is deuterium, R ２１ ~R ２７ At least one of them is light hydrogen.

11. Compounds represented by general formula (G2). (In general formula (G2), R １ ~R ７ , R １１ ~R １７ , and R ２１ ~R ３２ Each of these independently represents hydrogen (including deuterium), a linear or branched alkyl group having 1 to 10 carbon atoms, or a cycloalkyl group having 3 to 10 carbon atoms. Also, R １ ~R ７ And R ２１ ~R ２７ At least one of them is deuterium, R １１ ~R １７ At least one of the following and R ２８ ~R ３２ At least one of them is light hydrogen.

12. Organic compounds represented by structural formulas (100) to (106).

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