Material for light-emitting apparatus, and light-emitting device

Abstract

To provide a light-emitting device with excellent characteristics.SOLUTION: In a material for a light-emitting apparatus including an organic compound, an inner product of a vector A connecting two atoms that are the farthest in a lowest excitation state of the organic compound and a vector B that is a transition dipole moment related to light emission of the organic compound is 2.5 or more. (A length of the vector A is nm, a magnitude of the vector B is debye, and a direction of the vector A is determined so that an angle with the vector B is 90° or less.)SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present invention relates to an organic compound, an organic semiconductor device, a light-emitting device, a photodiode sensor, a display module, a lighting module, a display device, an electronic device, a lighting device, and an electronic device. Note that one aspect of the present invention is not limited to the above technical field. The technical field of one aspect of the invention disclosed in this specification and the like relates to an article, a method, or a manufacturing method. Alternatively, one aspect of the present invention relates to a process, a machine, a manufacture, or a composition of matter. Therefore, more specifically, examples of the technical field of one aspect of the present invention disclosed in this specification include semiconductor devices, display devices, liquid crystal display devices, lighting devices, power storage devices, storage devices, imaging devices, their driving methods, or their manufacturing methods.

Background Art

[0002] The practical application of light-emitting devices (also referred to as organic EL elements) that utilize electroluminescence (EL) using organic compounds is progressing. The basic configuration of these light-emitting devices is such that an organic compound layer containing a light-emitting center substance is sandwiched between a pair of electrodes. By applying a voltage to this device to inject carriers and utilizing the recombination energy of the carriers, light emission from the light-emitting center substance can be obtained.

[0003] Since the light-emitting device is self-luminous, a display device using the light-emitting device as a pixel has higher visibility than a liquid crystal display device and does not require a backlight. In addition, a display device using such a light-emitting device can be manufactured to be thin and lightweight, which is also a great advantage. Furthermore, it is also characterized by a very fast response speed.

[0004] In addition, since these light-emitting devices can form a light-emitting layer continuously in a planar shape, planar light emission can be obtained. This is a characteristic that is difficult to achieve with point light sources typified by incandescent bulbs and LEDs, or line light sources typified by fluorescent lamps. Therefore, it has high utility value as a surface light source that can be applied to lighting and the like.

[0005] As described above, display devices and lighting devices using such light-emitting devices are suitable for various electronic devices, and research and development are being advanced to obtain light-emitting devices having better characteristics.

[0006] Patent Document 1 discloses a light-emitting element in which a light-emitting substance is oriented and formed into a film to control the light-emitting direction and improve the extraction efficiency.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Non-Patent Documents

[0008]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] In one aspect of the present invention, an object is to provide a light-emitting device having good characteristics. Or, in one aspect of the present invention, an object is to provide a light-emitting device having good reliability. Or, in one aspect of the present invention, an object is to provide a light-emitting device having a low driving voltage. Or, in one aspect of the present invention, an object is to provide a light-emitting device having good reliability and a low driving voltage.

[0010] Or, in one aspect of the present invention, an object is to provide a light-emitting device capable of providing a display device having good characteristics. Or, in one aspect of the present invention, an object is to provide a light-emitting device capable of providing a display device having good reliability. Or, in one aspect of the present invention, an object is to provide a display device having a low driving voltage. Or, in one aspect of the present invention, an object is to provide a light-emitting device capable of providing a display device having a low driving voltage and good reliability.

[0011] Or, an object is to provide any one of an organic semiconductor device, a light-emitting device, a light-receiving device, a display device, an electronic device, and a lighting device having low power consumption. Or, an object is to provide any one of an electronic device and a lighting device having high reliability.

[0012] The present invention only needs to solve any one of the above-mentioned problems.

Means for Solving the Problems

[0013] One aspect of the present invention is a material for a light-emitting device containing an organic compound, wherein the inner product of a vector A connecting two most distant atoms in the lowest excited state of the organic compound and a vector B of a transition dipole moment related to the light emission of the organic compound is 2.5 or more. (However, the length of the vector A is in nm, the magnitude of the vector B is in debye, and the direction of the vector A is determined so that the angle formed with the vector B is 90° or less.)

[0014] Alternatively, another aspect of the present invention is a material for a light-emitting device containing an organometallic complex, wherein the inner product of the vector A connecting the two most distant atoms in the lowest triplet excited state of the organometallic complex and the vector B of the transition dipole moment related to the light emission of the organometallic complex is 2.5 or more. (However, the length of vector A is in nm, the magnitude of vector B is in debye, and the direction of vector A is determined such that the angle formed with vector B is 90° or less.)

[0015] Alternatively, another aspect of the present invention is a material for a light-emitting device having the above configuration, wherein the organometallic complex is a four-coordinate complex.

[0016] Alternatively, another aspect of the present invention is a material for a light-emitting device having the above configuration, wherein the organometallic complex is a cyclometalated complex.

[0017] Alternatively, another aspect of the present invention is a material for a light-emitting device having the above configuration, wherein a six-membered ring is formed by the metal contained in the organometallic complex and a part of the atoms contained in the ligand contained in the organometallic complex.

[0018] Alternatively, another aspect of the present invention is a material for a light-emitting device having the above configuration, wherein a five-membered ring is formed by the metal contained in the organometallic complex and a part of the atoms contained in the ligand contained in the organometallic complex.

[0019] Alternatively, another aspect of the present invention is a material for a light-emitting device having the above configuration, wherein the organometallic complex contains a plurality of five-membered rings.

[0020] Alternatively, another aspect of the present invention is a material for a light-emitting device having the above configuration, wherein the ligand in the organometallic complex contains carbazole.

[0021] Alternatively, another aspect of the present invention is a material for a light-emitting device having the above configuration, wherein the metal contained in the organometallic complex is platinum.

[0022] Alternatively, another aspect of the present invention is a material for a light-emitting device in which, in the above configuration, the luminescence quantum yield of the organometallic complex is 0.60 or more.

[0023] Alternatively, another aspect of the present invention is a material for a light-emitting device in which, in the above configuration, the molecular orientation parameter a of the light emitted from a light-emitting device including an organometallic complex as a light-emitting center substance in a light-emitting layer is 0.23 or less.

[0024] Alternatively, another aspect of the present invention is a material for a light-emitting device in which, in the above configuration, the light-emitting layer contains a host material and a light-emitting center substance.

[0025] Alternatively, another aspect of the present invention is a light-emitting device having a first electrode, a second electrode, and a light-emitting layer located between the first electrode and the second electrode, wherein the light-emitting layer contains an organic compound in which the inner product of a vector A connecting two atoms that are farthest apart in the excited state and a vector B of the transition dipole moment is 2.5 or more. (However, the length of vector A is in nm, the magnitude of vector B is in debye, and the direction of vector A is determined such that the angle formed with vector B is 90° or less.)

[0026] Alternatively, another aspect of the present invention is a light-emitting device having a first electrode, a second electrode, and a light-emitting layer located between the first electrode and the second electrode, wherein the light-emitting layer contains an organometallic complex in which the inner product of a vector A connecting two atoms that are farthest apart in the excited state and a vector B of the transition dipole moment is 2.5 or more. (However, the length of vector A is in nm, the magnitude of vector B is in debye, and the direction of vector A is determined such that the angle formed with vector B is 90° or less.)

[0027] Alternatively, another aspect of the present invention is a light-emitting device in which, in the above configuration, the organometallic complex is a four-coordinate complex.

[0028] Alternatively, another aspect of the present invention is a light-emitting device in which, in the above configuration, the organometallic complex is a cyclometalated complex.

[0029] Or, another aspect of the present invention is a light-emitting device in which a six-membered ring is formed by a metal contained in an organometallic complex and a part of atoms contained in a ligand contained in the organometallic complex in the above configuration.

[0030] Or, another aspect of the present invention is a light-emitting device in which a five-membered ring is formed by a metal contained in an organometallic complex and a part of atoms contained in a ligand contained in the organometallic complex in the above configuration.

[0031] Or, another aspect of the present invention is a light-emitting device in which the organometallic complex contains a plurality of five-membered rings in the above configuration.

[0032] Or, another aspect of the present invention is a light-emitting device in which the ligand in the organometallic complex contains carbazole in the above configuration.

[0033] Or, another aspect of the present invention is a light-emitting device in which the metal contained in the organometallic complex is platinum in the above configuration.

[0034] Or, another aspect of the present invention is a light-emitting device in which the photoluminescence quantum yield of the organometallic complex is 0.60 or more in the above configuration.

[0035] Or, another aspect of the present invention is a light-emitting device in which the molecular orientation parameter a of the light emitted from a light-emitting device containing the organometallic complex as a light-emitting center substance in the light-emitting layer is 0.23 or less in the above configuration.

[0036] Or, another aspect of the present invention is a light-emitting device in which the light-emitting layer contains a host material and a light-emitting center substance in the above configuration.

[0037] Or, another aspect of the present invention is a display device including the light-emitting device described above.

[0038] Or, another aspect of the present invention is an electronic device having the above light-emitting device and a sensor, an operation button, a speaker, or a microphone.

[0039] Alternatively, another aspect of the present invention is a lighting device including the above-described light-emitting device and a housing.

Advantages of the Invention

[0040] In one aspect of the present invention, a light-emitting device with high luminous efficiency can be provided. Alternatively, in one aspect of the present invention, a light-emitting device with good reliability can be provided. Alternatively, any one of a display device, an electronic device, and a lighting device with low power consumption can be provided. Alternatively, any one of a display device, an electronic device, and a lighting device with high reliability can be provided.

[0041] Note that the description of these effects does not prevent the existence of other effects. Note that one aspect of the present invention does not necessarily have all of these effects. Note that other effects will be apparent from the description in the specification, drawings, claims, etc., and it is possible to extract these other effects from the description in the specification, drawings, claims, etc.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0043] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and those skilled in the art can easily understand that the form and details thereof can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments shown below.

[0044] In this specification and the like, a device manufactured using a metal mask or an FMM (fine metal mask, high-definition metal mask) may be referred to as a device having an MM (metal mask) structure. Also, in this specification and the like, a device manufactured without using a metal mask or an FMM may be referred to as a device having an MML (metal maskless) structure.

[0045] (Embodiment 1) As a factor that has a great influence on the external quantum efficiency, there is the light extraction efficiency (χ). The light extraction efficiency (χ) is also related to the structure, lamination, etc. of the light-emitting device, but in an organic EL device on a glass substrate, it is generally said to be 20% - 30%. However, this assumes that the light emission is isotropic, so if anisotropy occurs in the light emission, this value will change. Here, since the light emission of the light-emitting center substance occurs in a direction perpendicular to the transition dipole of the molecule, it is possible to improve the light extraction efficiency (χ) by controlling the orientation state of the molecules.

[0046] However, even if the orientation state is controlled, when the luminescence quantum yield of the light-emitting center substance itself is small, it is difficult to obtain a light-emitting device with good luminous efficiency only by that.

[0047] Also, it is generally known that a highly planar structure such as an organometallic complex represented by a platinum complex 1 of the following structural formula is advantageous for molecular orientation. However, platinum complex 2 and platinum complex 3 represented by the following structural formula can realize a light-emitting device showing better luminous efficiency than platinum complex 1 despite not having high planarity. The present inventors have found that by estimating the contribution of the transition dipole moment to the improvement of the luminous efficiency from a different perspective from planarity, a light-emitting device with good luminous efficiency can be provided.

[0048]

Chemical formula

[0049] In one aspect of the present invention, there is provided a material for a light-emitting device or a material for a light-emitting device including an organic compound or an organometallic complex in which the inner product of a vector A connecting two atoms that are farthest apart in the lowest excited state and a vector B that is a transition dipole moment related to light emission is 2.5 or more, more preferably 4.0 or more. The direction of the vector A is defined such that the angle formed with the vector B is 90° or less. The unit of the vector B is debye, and the unit of the vector A is nm in order to align the digits of the magnitudes of the vectors. The lowest excited state is the triplet lowest excited state in the case of a platinum complex, and a transition dipole moment having a large magnitude in the lowest excited state and affecting the shape of the emission spectrum is used.

[0050] The direction of the vector A connecting two atoms that are farthest apart in the lowest excited state is parallel to the direction of the longest side of the molecule (also referred to as the long side direction). A small angle formed between this vector A and the vector B of the transition dipole moment is advantageous for molecular orientation. Also, a large transition dipole moment is advantageous for improving the light emission quantum yield.

[0051] Therefore, in the organic compound or the organometallic complex having these characteristics, the inner product of the vector A connecting two atoms that are farthest apart in the lowest excited state and the vector B of the transition dipole moment becomes large. In the organic compound or the organometallic complex, when this value is 2.5 or more, preferably 4.0 or more, a light-emitting device or a light-emitting device using a material for a light-emitting device or a material for a light-emitting device including the organic compound or the organometallic complex can be a light-emitting device or a light-emitting device having good light emission efficiency. Also, it can be a light-emitting device or a light-emitting device having good reliability.

[0052] As described above, the luminescence of an organic compound or an organometallic complex occurs in a direction perpendicular to the transition dipole of the molecule. In a certain molecule, the direction in which the vector connecting the two farthest atoms extends (the long side direction) is more likely to be randomly arranged horizontally with respect to the film formation surface when the molecule is formed into a film, as compared with other directions. Therefore, it is preferable that the angle formed by vector B, which is the vector of the transition dipole moment, and vector A is small.

[0053] Note that although vector A, which is the vector connecting the two farthest atoms in the ground state and the vector connecting the two farthest atoms in the lowest excited state, are different vectors, since a significant difference in direction is unlikely to occur, vector A can be used as an index of the ease of horizontal alignment with respect to the film formation surface.

[0054] In addition, the transition dipole moment represents the ease of transition between two electronic states, and since a larger value makes the transition easier, it is advantageous for improving the luminescence quantum yield, and it is preferable that the value of vector B is large.

[0055] Therefore, it is preferable that the inner product of vector A and vector B is large, and by using a material for a light-emitting device or a material for a light-emitting device containing an organic compound or an organometallic complex in which the inner product is 2.5 or more, more preferably 4.0 or more, light emission can be extracted more efficiently.

[0056] Note that when there are a plurality of vectors connecting the two farthest atoms in the lowest excited state in the same organic compound or organometallic complex, the vector with the smaller angle formed with vector B shall be regarded as vector A.

[0057] In addition, the organic compound or organometallic complex contained in the material for a light-emitting device or the material for a light-emitting device is assumed to have a function of exhibiting light in the light-emitting device or the light-emitting device. Examples of those having a function of exhibiting light include a light-emitting center substance, a color conversion material, and the like. Note that the photoluminescence quantum yield of the organic compound or organometallic complex is preferably 0.60 or more, and more preferably 0.70 or more. The photoluminescence quantum yield is measured by forming a solution in which each material is dispersed in PMMA (poly(methyl methacrylate)) at an appropriate concentration (for example, 4.8 wt%) using deoxygenated dichloromethane as a solvent on a quartz substrate by a drop casting method, drying it under a nitrogen stream in a glove box (for example, at room temperature for 30 minutes), and measuring the obtained PMMA film.

[0058] In addition, the material for a light-emitting device or the material for a light-emitting device may be composed only of the above-described organic compound or organometallic complex, or may contain other substances.

[0059] FIG. 1(A) is a diagram showing a light-emitting device according to one embodiment of the present invention. The light-emitting device according to one embodiment of the present invention has a first electrode 101, a second electrode 102, and an organic compound layer 103 on an insulating layer 1000, and the organic compound layer 103 has a light-emitting layer 113. Note that the organic compound layer 103 may have other functional layers such as a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer.

[0060] The light-emitting device according to one embodiment of the present invention has the above-described material for a light-emitting device or the material for a light-emitting device in the light-emitting layer 113. The light-emitting layer 113 preferably further has a host material, and the material for a light-emitting device or the material for a light-emitting device is preferably dispersed in the host material. Note that the host material may be composed of a plurality of organic compounds. In addition, an organic compound that functions as a host material may be included in the material for a light-emitting device or the material for a light-emitting device.

[0061] A light-emitting device according to one embodiment of the present invention having the above-described configuration includes, as a light-emitting center material, an organic compound or an organometallic complex in which the inner product of a vector A connecting two most distant atoms in the lowest excited state and a vector B of a transition dipole moment related to light emission is 2.5 or more, more preferably 4.0 or more, whereby a light-emitting device with good luminous efficiency can be obtained. Further, a light-emitting device with good reliability can be obtained.

[0062] Furthermore, when the molecular orientation parameter a of the light emitted by the light-emitting device is 0.25 or less, preferably 0.23 or less, due to having good orientation characteristics, light extraction becomes easy, and a more efficient light-emitting device can be obtained. That is, a light-emitting device is more preferable in which an organic compound or an organometallic complex in which the inner product of vector A and vector B is 2.5 or more, more preferably 4.0 or more, is included in the light-emitting layer as a light-emitting center material, and the molecular orientation parameter a of the light emitted by the light-emitting device is 0.25 or less, preferably 0.23 or less.

[0063] In addition, by being used in the light-emitting layer, a light-emitting device in which the molecular orientation parameter a of light is 0.25 or less, preferably 0.23 or less, can be provided, and a material for a light-emitting device or a material for a light-emitting device including an organic compound or an organometallic complex in which the inner product of vector A and vector B is 2.5 or more, more preferably 4.0 or more, is more preferable.

[0064] The molecular orientation parameter a is a value estimated for the molecular orientation from the light-emitting state of the device. The emission angle dependence (spatial emission pattern) of the emission intensity of the light-emitting device reflects the spatial distribution of the transition dipoles of the light-emitting center material. By analyzing this spatial distribution, the orientation state of the light-emitting device can be examined. In this method, since the light emission itself of the light-emitting device is observed and analyzed, even if the light-emitting center material is dispersed in the host material and its concentration is low, it is possible to examine in what orientation state the light-emitting center material is in the relationship between the light-emitting surface and the transition dipole moment in the light-emitting layer.

[0065] Therefore, a light-emitting device using the above-described material for a light-emitting device or a material for a light-emitting device in the light-emitting layer, with a molecular orientation parameter a of 0.25 or less, preferably 0.23 or less, can be a light-emitting device with good efficiency.

[0066] <Method for obtaining the inner product of vector A and vector B> Taking a platinum complex as an example of an organic compound or an organometallic complex contained in the material for a light-emitting device or the material for a light-emitting device, a method for obtaining the inner product of a vector A connecting the two most distant atoms in the atomic arrangement of the lowest triplet excited state and a vector B of the transition dipole moment related to light emission will be described.

[0067] Here, examples of obtaining the inner product of vector A and vector B are shown for three platinum complexes: platinum complex 1, platinum complex 2, and platinum complex 3.

[0068] For the structure for performing quantum chemical calculations, conformational analysis was performed and sampled using Macro Model with the Maestro GUI manufactured by Schrödinger. Using the quantum chemical calculation software Jaguar, the most stable structure in the singlet ground state was calculated by the density functional method (DFT), and the structure of the most stable conformation was determined. In this structure, DYALL-2ZCVP_ZORA-J-PT-GEN++ was used for Pt atoms as the basis function, LACVP** was used for other atoms, ωB97X-D (ω = 0.1) was used as the functional, and the time-dependent density functional method (TD-DFT) using the spin-free ZORA relativistic Hamiltonian was used to calculate the lowest triplet excited state as the excited state, and the most stable structure was obtained. In the same structure, a single point energy calculation of the excited state using the spin-orbit ZORA relativistic Hamiltonian was performed to visualize the vector B of the transition dipole moment related to light emission. Furthermore, in the same structure, a vector A connecting the two most distant atoms was defined so that the angle formed with vector B was 90° or less, and the angle formed with vector B was obtained. As an example, a diagram showing the angles formed by each vector in platinum complex 2 is shown in Figure 2. The results are also shown in Table 1.

[0069]

Table 1

[0070] Platinum complex 2 and platinum complex 3 are known to have better orientation characteristics than platinum complex 1 from the orientation parameter a obtained by the experiments described later. As shown in Table 1, this is considered to be correlated with the difference in the inner product between vector A and vector B. Platinum complex 2 and platinum complex 3 have a structure with a large contribution to improving the luminescence efficiency of the transition dipole moment. A light-emitting device or a light-emitting device using a light-emitting device material or a light-emitting device material containing platinum complex 2 and platinum complex 3 can be a light-emitting device or a light-emitting device with good luminescence efficiency.

[0071] It is considered that platinum complex 1 has a small inner product between vector A and vector B and a small contribution to improving the luminescence efficiency of the transition dipole moment.

[0072] Thus, a light-emitting device or a light-emitting device using a light-emitting device material or a light-emitting device material having an organic compound or an organometallic complex with a large inner product between vector A and vector B can be a light-emitting device or a light-emitting device with good efficiency.

[0073] Note that the organic compound or organometallic complex contained in the light-emitting device material or the light-emitting device material is preferably an organometallic complex because it exhibits high phosphorescence emission efficiency due to a fast intersystem crossing process between the singlet state and the triplet state. Further, it is preferable that the organometallic complex is a cyclometalated complex because it forms a strong carbon-metal bond and exhibits high phosphorescence emission efficiency due to metal-ligand charge transfer (MLCT) properties in the excited state.

[0074] In addition, it is preferable that a ring is formed by the metal contained in the organometallic complex and a part of the atoms contained in the ligand, because the planarity of the organometallic complex is increased. Also, it is preferable because the long side directions of the singlet ground state and the lowest triplet excited state do not change significantly. Note that a 6-membered ring or a 5-membered ring is stable and preferable for the ring. In addition, it is preferable that a plurality of the rings are contained in the organometallic complex because the planarity is further increased, and also because the change in the long side direction between the singlet ground state and the lowest triplet excited state is small. When there are a plurality of the rings, it is preferable that both a 6-membered ring and a 5-membered ring are included, and it is also preferable that a plurality of 5-membered rings are included.

[0075] In addition, since the organometallic complex contains a carbazole skeleton in the ligand, it can maintain a high energy level of the lowest triplet excited state (T1), be adjusted to an appropriate HOMO-LUMO level, contribute to hole transportability or charge confinement in the light-emitting layer, and has high stability against electrons. Therefore, high luminous efficiency can be obtained, the driving voltage is low, and it is preferable because of excellent durability.

[0076] Note that since the platinum complex has four-coordination, it is easy to maintain the planarity of the molecule, so the inner product of vector A and vector B tends to be large, which is preferable.

[0077] <Method for calculating molecular orientation parameter a> Subsequently, the method for calculating the molecular orientation parameter a will be described. By comparing the measured angular dependence of the emission intensity of the light-emitting device with the calculated value of the angular dependence of the emission intensity calculated assuming the parameter a (see the following formula (1)) representing the orientation of the light-emitting molecules by a device simulator, a reasonable numerical value of the molecular orientation parameter a for the measured light-emitting device can be estimated, and the orientation state of the light-emitting central substance in the light-emitting device can be examined (see Non-Patent Document 2).

[0078] The inventors of the present invention have also focused on the shape of the emission spectrum obtained from the device simulator, and have compared the measured values with the calculated values for the shape of the emission spectrum and the change in the shape of the emission spectrum depending on the angle, and have performed fitting. Further, as the emission intensity in the measurement and calculation, the area intensity of the emission spectrum is used instead of the emission intensity at a specific wavelength. By these methods newly applied by the inventors of the present invention, unlike Non-Patent Document 2, it has become possible to estimate the parameter a with high accuracy.

[0079] Figure 3 shows the relationship between the observation direction of the measuring instrument in the measurement of the spatial distribution of the emission intensity and each vector component of the transition dipole moment on the substrate. Since the transition dipole moment is a vector, it can be synthesized and decomposed, and the average transition dipole moment in the light-emitting center substance in the light-emitting layer can be decomposed into components in the x-axis direction (TEh component), y-axis direction (TMh component), and z-axis direction (TMv component) that are orthogonal to each other.

[0080] Here, as described above, it is known that the light emission from the molecule is emitted in a direction perpendicular to the transition dipole moment (any direction in the perpendicular plane). Among the components decomposed in the above three directions, the TEh component and the TMh components (x-axis direction and y-axis direction) are transition dipole moments horizontal to the substrate surface, so the emission direction thereof is perpendicular to the substrate, and it can be said that they are components that exhibit light emission that is easy to extract. On the other hand, since the TMv component (z-axis direction) is a transition dipole moment perpendicular to the substrate surface, the emission direction thereof is horizontal to the substrate, and it is a component that exhibits light emission that is difficult to extract.

[0081] In Figure 3, the figure extending from the center of the arrow representing the vector of each component is a schematic diagram showing the emission intensity entering the detector in that direction when the direction of the detector is changed from the front of the substrate (θ = 0 degrees) to almost horizontal with the substrate (θ = 90 degrees), and the linear distance from the center is proportional to the intensity.

[0082] Since the detector is present in the direction in which light is emitted for the TEh component, the intensity of the detected light (i.e., the straight-line distance from the center of the arrow in the figure to the center of the arrow of the figure emerging from the center of the arrow in the figure) remains constant even when the angle of the substrate is changed, and the figure emerging from the center of the arrow in the figure shows a perfect sector. On the other hand, the figures emerging from the center of the arrow in the figure for the TMh component and the TMv component are distorted, indicating that the intensity of the detected light varies greatly depending on the angle θ of the detector with respect to the substrate. As shown in the figure, the TMh component has a strong intensity in the region where θ is small (closer to the front with respect to the substrate), and the TMv component has a strong intensity in the region where θ is large (in the direction with an angle with respect to the substrate). At this time, the emission intensity measured by the measuring instrument (the emission intensity with respect to the wavelength λ at a certain angle θ: I λ (θ, λ)) can be expressed as Equation (1).

[0083] [Number]

[0084] In the formula, I TMv , I TMh , I TEh represent the spatial intensity distribution of the light emitted from the transition dipole in the arrangement shown in Figure 3. In the formula, a represents the ratio of the transition dipole (TMv component) arranged perpendicular to the film surface. On the other hand, 1 - a represents the ratio of the transition dipoles arranged horizontally (TMh component, TEh component). That is, a can also be regarded as a parameter representing the orientation of the transition dipole of the luminescent molecule.

[0085] Note that in the formula, if the transition dipole is arranged only in the completely horizontal direction with respect to the substrate, the TMv component disappears, so a = 0. On the other hand, if the transition dipole is arranged only in the vertical direction with respect to the substrate, a = 1. Also, when the orientation of the transition dipole is random, since the orientation of the transition dipole is considered to be isotropic at 1:1:1 with respect to the x-axis, y-axis, and z-axis, the ratio of the component perpendicular to the substrate (TMv component) to the component horizontal to the substrate (TMh component and TEh component) is 1:2, so a = 1 / 3 (about 0.33).

[0086] Here, as described above, I TEh has a constant intensity regardless of the angle, but I TMv , I TMh changes its magnitude depending on the angle (θ) of the substrate with respect to the measuring instrument as described above. Therefore, by changing θ and measuring the emission intensity, the value of a can be obtained from the change of the intensity with respect to θ.

[0087] Note that, in this case, I TEh whose intensity does not change with the angle hinders the measurement. However, since the amplitude direction of the electric field of the emitted light is the same as the direction of the transition dipole moment, I TEh is S-polarized light, I TMv , I TMh is P-polarized light. Therefore, it is possible to perform the measurement excluding the TEh component by inserting a linear polarizer in the direction perpendicular to the substrate surface.

[0088] Also, when comparing the TMv component and the TMh component, the emission direction of the TMh component is mainly perpendicular to the substrate, and the emission direction of the TMv component is mainly horizontal to the substrate. However, in a light-emitting device that obtains light emission from a solid, most of the light emission of the TMv component is totally reflected and cannot be taken out to the outside. On the other hand, the light emission of the TMh component is more likely to be taken out to the outside than the TMv component. Furthermore, in a light-emitting device with an optically optimized film thickness, the light emission of the TMh component whose emission direction is mainly perpendicular to the substrate is enhanced by interference, so that the light emission intensity of the TMh component increases (therefore, the light emission efficiency is maximized). That is, unless the orientation parameter a is extremely close to 1, in an element with an optically optimized film thickness, a very large difference occurs between the light emission intensities of the TMv component and the TMh component. That is, in a light-emitting device with a maximized light emission efficiency, most of the observed light emission is the TMh component. Thus, when the difference in the light emission intensities of the TMv component and the TMh component is significantly different, it is difficult to experimentally extract the contribution of the component with the smaller intensity (in this case, the TMv component) from the angular distribution of the light emission intensity.

[0089] Therefore, in this embodiment, by suppressing the forward emission intensity as much as possible using the interference effect (that is, reducing the emission of the TMh component as much as possible using optical interference), an orientation measurement device with film thickness adjustment is prepared and measured so that the value of a can be easily obtained. Specifically, by setting the distance between the light-emitting region and the cathode to nλ / 2 (where n is an integer), an element with reduced forward luminance is fabricated and used for measurement. The film thickness adjustment is usually performed by thickening the electron transport layer doped with an alkali metal. However, since there is a limit to the conductivity of the film, it is likely to cause an increase in the driving voltage and a breakdown of the carrier balance. Therefore, it is preferable to use a hole transport material and a composite material containing a material showing acceptor properties in the hole transport material for this film thickness adjustment.

[0090] As the composite material, it is possible to use the same material as the composite material preferably used for the hole injection layer described later in Embodiment 2. In the orientation measurement device, in order to suppress the increase in the driving voltage, it is preferable to use molybdenum oxide as the acceptor material.

[0091] An example of the device structure of the orientation measurement device is shown below.

[0092]

Table 2

[0093] When the molecular orientation parameter was measured using such a device, it was calculated that platinum complex 1 had a = 0.26, platinum complex 2 had a = 0.21, and platinum complex 3 had a = 0.22. Since random orientation has a = 0.33 and perfect horizontal orientation has a = 0, it can be seen that the devices using any of the platinum complexes have more horizontal orientation components than random orientation. In particular, it can be seen that platinum complex 2 and platinum complex 3 have more horizontal orientation components compared to platinum complex 1.

[0094] Figure 4 shows the external quantum efficiency-current density characteristics of light-emitting devices using platinum complexes 1 to 3 as light-emitting center materials. Light-emitting device 1 uses platinum complex 1, light-emitting device 2 uses platinum complex 2, and light-emitting device 3 uses platinum complex 3 as the light-emitting center materials, respectively. Note that the device configurations and conditions other than the light-emitting center materials are the same.

[0095] As can be seen from Figure 4, light-emitting devices 2 and 3 exhibit better external quantum efficiency-current density characteristics compared to light-emitting device 1. Thus, a light-emitting device using platinum complex 2 and platinum complex 3 with a large inner product of vector A and vector B and a molecular orientation parameter a of 0.23 or less as the light-emitting center material can be a light-emitting device with much higher luminous efficiency compared to a light-emitting device using platinum complex 1 as the light-emitting center material.

[0096] As described above, the light-emitting device according to one aspect of the present invention can provide a light-emitting device with good luminous efficiency by using a material for a light-emitting device or a material for a light-emitting device containing an organic compound or an organometallic complex in which the inner product of vector A and vector B is 2.5 or more, preferably 4.0 or more. Further, when the material for a light-emitting device or the material for a light-emitting device is used as the light-emitting center material, it has been found that a light-emitting device with better efficiency can be provided because the molecular orientation parameter a of the light-emitting device is 0.23 or less.

[0097] (Embodiment 2) In this embodiment, a light-emitting device, which is an organic semiconductor device according to one aspect of the present invention, will be described in detail. FIG. 1(A) shows a diagram representing the light-emitting device according to one aspect of the present invention. The light-emitting device according to one aspect of the present invention has an organic compound layer 103 between a first electrode 101 formed on an insulating layer 1000 and a second electrode 102 facing the first electrode. The organic compound layer 103 has at least a light-emitting layer 113 and may further include other functional layers. In FIGS. 1(A) and (B), as an example, an example in which the organic compound layer 103 includes a hole injection layer 111, a hole transport layer 112, and an electron transport layer 114 is shown, but it may have an electron injection layer 115, an exciton blocking layer, a charge generation layer, or the like. Note that, among the hole transport layer 112, the layer in contact with the light-emitting layer 113 may be particularly referred to as an electron blocking layer, and among the electron transport layer 114, the layer in contact with the light-emitting layer may be particularly referred to as a hole blocking layer.

[0098] In this embodiment, a case where the first electrode 101 functions as an anode and the second electrode 102 functions as a cathode will be described as an example, but the reverse may also be possible. Further, the first electrode 101 and the second electrode 102 are formed as a single-layer structure or a stacked structure. When having a stacked structure, the layer in contact with the organic compound layer 103 functions as an anode or a cathode. When the electrode has a stacked structure, there are no restrictions on the work function for the layers other than the layer in contact with the organic compound layer 103, and a material may be selected according to the required characteristics such as the resistance value, processability, reflectance, transmittance, and stability.

[0099] Note that the light-emitting layer contains the material for the light-emitting device described in Embodiment 1. Thereby, the light-emitting device according to one aspect of the present invention can be a light-emitting device with good luminous efficiency.

[0100] The anode is preferably formed using a metal, alloy, conductive compound, or a mixture thereof having a large work function (specifically, 4.0 eV or more). Specifically, for example, indium tin oxide (ITO: Indium Tin Oxide), indium tin silicon oxide (ITSO: Indium Tin Silicon Oxide) containing silicon or silicon oxide, indium zinc oxide, indium tungsten zinc oxide (IWZO) containing tungsten oxide and zinc oxide, etc. may be mentioned. These conductive metal oxide films are usually formed by a sputtering method, but may also be produced by applying a sol-gel method or the like. As an example of the production method, indium zinc oxide can be formed by a sputtering method using a target in which 1 to 20 wt% of zinc oxide is added to indium oxide. Also, indium tungsten zinc oxide (IWZO) containing tungsten oxide and zinc oxide can also be formed by a sputtering method using a target containing 0.5 to 5 wt% of tungsten oxide and 0.1 to 1 wt% of zinc oxide with respect to indium oxide. In addition, materials used for the anode include, for example, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti), aluminum (Al), or nitrides of metal materials (for example, titanium nitride), etc. Also, a layer formed by laminating these may be used as the anode. For example, a film laminated in the order of Al, Ti, and ITSO on Ti is preferable because it has good reflectivity, is highly efficient, and enables high definition of several thousand ppi. Alternatively, graphene can also be used as the material for the anode. By using a composite material capable of forming the hole injection layer 111 described later as a layer (typically the hole injection layer) in contact with the anode, the electrode material can be selected regardless of the work function.

[0101] The hole injection layer 111 is provided in contact with the anode and has a function of facilitating the injection of holes into the organic compound layer 103. The hole injection layer 111 is phthalocyanine (abbreviation: H 2It can be formed by phthalocyanine-based compounds or phthalocyanine-based complex compounds such as phthalocyanine (Pc), copper phthalocyanine (abbreviation: CuPc), aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), or polymers such as poly(3,4-ethylenedioxythiophene) / polystyrene sulfonic acid (abbreviation: PEDOT / PSS).

[0102] Further, the hole injection layer 111 may be formed of a substance having electron acceptor properties. As the substance having acceptor properties, an organic compound having an electron-withdrawing group (such as a halogen group or a cyano group) can be used, and examples thereof include 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviation: F4-TCNQ), chloranil, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (abbreviation: HAT-CN), 1,3,4,5,7,8-hexafluorotetracyano-naphthoquinodimethane (abbreviation: F6-TCNNQ), 2-(7-dicyanomethylene-1,3,4,5,6,8,9,10-octafluoro-7H-pyrene-2-ylidene) malononitrile, and the like. In particular, a compound in which an electron-withdrawing group is bonded to a condensed aromatic ring having a plurality of heteroatoms, such as HAT-CN, is thermally stable and preferable. Further, a [3]radialene derivative having an electron-withdrawing group (particularly a halogen group such as a fluoro group or a cyano group) is preferable because of its very high electron accepting property. Specifically, α,α’,α’’-1,2,3-cyclopropanetriylidene tris[4-cyano-2,3,5,6-tetrafluorobenzeneacetonitrile], α,α’,α’’-1,2,3-cyclopropanetriylidene tris[2,6-dichloro-3,5-difluoro-4-(trifluoromethyl)benzeneacetonitrile], α,α’,α’’-1,2,3-cyclopropanetriylidene tris[2,3,4,5,6-pentafluorobenzeneacetonitrile], and the like can be mentioned. As the substance having acceptor properties, in addition to the organic compounds described above, transition metal oxides such as molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, and manganese oxide can be used. The substance having acceptor properties can extract electrons from the adjacent hole transport layer (or hole transport material) by applying an electric field.

[0103] Further, the hole injection layer 111 is preferably formed of a composite material containing the above-mentioned acceptor material and a substance having hole transport properties.

[0104] As the substance having hole transporting property used in the composite material, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. Note that as the substance having hole transporting property used in the composite material, it is preferably a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more. The substance having hole transporting property used in the composite material is preferably a compound having a condensed aromatic hydrocarbon ring or a π-electron excess type heteroaromatic ring. As the condensed aromatic hydrocarbon ring, an anthracene ring, a naphthalene ring, etc. are preferable. Further, as the π-electron excess type heteroaromatic ring, a condensed aromatic ring containing at least any one of a pyrrole skeleton, a furan skeleton, and a thiophene skeleton in the ring is preferable, and specifically, a carbazole ring, a dibenzothiophene ring, or a ring in which an aromatic ring or a heteroaromatic ring is further condensed thereto is preferable.

[0105] Such a substance having hole transporting property more preferably has any one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, it may be an aromatic amine having a substituent containing 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. Note that it is preferable that these substances having hole transporting property are substances having an N,N-bis(4-biphenyl)amino group because a light-emitting device having a good lifetime can be manufactured.

[0106] Examples of substances having hole-transporting properties as described above include, specifically, N-(4-biphenyl)-6,N-diphenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BnfABP), N,N-bis(4-biphenyl)-6-phenylbenzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf), 4,4'-bis(6-phenylbenzo[b]naphtho[1,2-d]furan-8-yl)-4''-phenyltriphenylamine (abbreviation: BnfBB1BP), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-6-amine (abbreviation: BBABnf(6)), N,N-bis(4-biphenyl)benzo[b]naphtho[1,2-d]furan-8-amine (abbreviation: BBABnf(8)), N,N-bis(4-biphenyl)benzo[b]naphtho[2,3-d]furan-4-amine (abbreviation: BBABnf(II)(4)), N,N-bis[4-(dibenzofuran-4-yl)phenyl]-4-amino-p-terphenyl (abbreviation: DBfBB1TP), N-[4-(dibenzothiophene-4-yl)phenyl]-N-phenyl-4-biphenylamine (abbreviation: ThBA1BP), 4-(2-naphthyl)-4',4''-diphenyltriphenylamine (abbreviation: BBAβNB), 4-[4-(2-naphthyl)phenyl]-4',4''-diphenyltriphenylamine (abbreviation: BBAβNBi), 4,4'-diphenyl-4''-(6;1'-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'-(carbazol-9-yl)biphenyl-4-yl]triphenylamine (abbreviation: YGTBi1BP), 4'-[4-(3-phenyl-9H-carbazol-9-yl)phenyl]tris(biphenyl-4-yl)amine (abbreviation: YGTBi1BP-02), 4-[4'-(carbazol-9-yl)biphenyl-4-yl]-4'-(2-naphthyl)-4''-phenyltriphenylamine (abbreviation: YGTBiβNB), N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-N-[4-(1-naphthyl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBNBSF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: BBASF), N,N-bis(biphenyl-4-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: BBASF(4)), N-(biphenyl-2-yl)-N-(9,9-dimethyl-9H-fluorene-2-yl)-9,9'-spirobi[9H-fluorene]-4-amine (abbreviation: oFBiSF), N-(biphenyl-4-yl)-N-(9,9-dimethyl-9H-fluoren-2-yl)dibenzofuran-4-amine (abbreviation: FrBiF), N-[4-(1-naphthyl)phenyl]-N-[3-(6-phenyldibenzofuran-4-yl)phenyl]-1-naphthylamine (abbreviation: mPDBfBNBN), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-[4-(9-phenylfluoren-9-yl)phenyl]triphenylamine (abbreviation: BPAFLBi), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF), N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-4-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-3-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-2-amine, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-phenyl-9'H-9,3':6',Examples include 9’’-tercarbazole (abbreviation: PSiCzGI), etc.

[0107] In addition, as substances having hole-transporting properties, as other aromatic amine compounds, N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4'-bis(N-{4-[N'-(3-methylphenyl)-N'-phenylamino]phenyl}-N-phenylamino)biphenyl (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), etc. can also be used.

[0108] By forming the hole injection layer 111, the injectability of holes becomes good, and a light-emitting device with a small driving voltage can be obtained.

[0109] Among substances having acceptor properties, organic compounds having acceptor properties are easy to vapor-deposit and easy to form films, so they are easy-to-use materials.

[0110] The hole transport layer 112 is formed by including a substance having hole-transporting properties. As the substance having hole-transporting properties, it preferably has a hole mobility of 1×10 -6 cm 2 / Vs or more.

[0111] Examples of the substance having hole transporting properties include compounds having an aromatic amine skeleton such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF); 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), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 3,9-bis(9-phenyl-9H-carbazol-3-yl)-9H-carbazole (abbreviation: PCCzPC), 9-(biphenyl-4-yl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: PCCzBP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-Bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylene-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-phenyl-9'H-9,3':6',Compounds having a carbazole skeleton such as 9’’-tercarbazole (abbreviation: PSiCzGI), 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: DBTFLP-III), 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV) and other compounds having a thiophene skeleton, 4,4’,4’’-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II) and other compounds having a furan skeleton can be mentioned. Among the above, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferable because they have good reliability, high hole transportability, and contribute to a reduction in driving voltage. Further, the organic compounds mentioned as the hole-transporting substances used in the composite material of the hole injection layer 111 can also be suitably used as the materials constituting the hole transport layer 112.,

[0112] The light-emitting layer 113 has the configuration as shown in Embodiment 1. The light-emitting center substance in the light-emitting layer 113 is preferably an organic compound or an organometallic complex contained in the light-emitting device material shown in Embodiment 1. By the organic compound or organometallic complex having an inner product of the vector A connecting the two most distant atoms in the lowest excited state and the vector B of the transition dipole moment of 2.5 or more, more preferably 4.0 or more, a light-emitting device with good luminous efficiency can be obtained.

[0113] The light-emitting center substance may be a fluorescent light-emitting substance, a phosphorescent light-emitting substance, a substance showing thermally activated delayed fluorescence (TADF), or other light-emitting substances as long as the inner product of the vector A and the vector B is 2.5 or more, more preferably 4.0 or more.

[0114] In addition, it is preferable that the luminescent center substance is an organometallic complex because it exhibits high phosphorescence emission efficiency due to a fast intersystem crossing process between the singlet state and the triplet state. Further, it is preferable that the organometallic complex is a cyclometalated complex because it forms a strong carbon-metal bond and exhibits high phosphorescence emission efficiency due to metal-ligand charge transfer (MLCT) properties in the excited state.

[0115] Moreover, it is preferable that a ring is formed by the metal contained in the organometallic complex and a part of the atoms contained in the ligand because the planarity of the organometallic complex is increased. Also, it is preferable because the long side directions of the singlet ground state and the triplet lowest excited state do not change significantly. Note that the ring is preferably a 6-membered ring or a 5-membered ring because it is stable. Note that it is preferable that a plurality of such rings are contained in the organometallic complex because the planarity is further increased and the change in the long side direction between the singlet ground state and the triplet lowest excited state is small. When there are a plurality of such rings, it is preferable that both a 6-membered ring and a 5-membered ring are included, and it is also preferable that a plurality of 5-membered rings are included.

[0116] In addition, since the organometallic complex contains a carbazole skeleton in the ligand, 1 it can maintain the energy level of the high triplet lowest excited state (T

[0117] ), adjust it to an appropriate HOMO-LUMO level, contribute to hole transport properties, and have high stability against electrons. Therefore, high emission efficiency can be obtained, the driving voltage is low, and it is preferable because of excellent durability.

[0118] Examples of substances that can be used as the organic compound or the organometallic complex include (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[3,5-di(methyl-d3)-4-phenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz35dm4ppy-d6)), (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[3,5-di(methyl-d3)-4-tert-butylphenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz35dm4tBuppy-d6)), and the like.

[0119] Among the light-emitting materials described below, a light-emitting device material or a light-emitting device material containing an organic compound or an organometallic complex in which the inner product of vector A and vector B calculated as in Embodiment 1 is 2.5 or more, preferably 4.0 or more, can also be used in the light-emitting layer to provide a light-emitting device with good luminous efficiency. That is, among the light-emitting materials described below, a light-emitting device with good luminous efficiency can be provided by using an organic compound or an organometallic complex in which the inner product of vector A and vector B calculated as in Embodiment 1 is 2.5 or more, preferably 4.0 or more, as the light-emitting center substance.

[0120] In the light-emitting layer 113 of the light-emitting device according to one aspect of the present invention, as the fluorescent light-emitting material that can be used as the light-emitting center substance, for example, those having an inner product of vector A and vector B of 2.5 or more, preferably 4.0 or more, can be used from among the following. Also, among the fluorescent light-emitting materials other than those described below, those having an inner product of vector A and vector B of 2.5 or more, preferably 4.0 or more, can also be used.

[0121] 5,6-bis[4-(10-phenyl-9-anthryl)phenyl]-2,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl-9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6FLPAPrn), N,N'-bis(3-methylphenyl)-N,N'-bis[3-(9-phenyl-9H-fluoren-9-yl)phenyl]pyrene-1,6-diamine (abbreviation: 1,6mMemFLPAPrn), N,N'-bis[4-(9H-carbazol-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazol-9-yl)-4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA), 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-anthryl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), perylene, 2,5,8,11-tetra-tert-butylperylene (abbreviation: TBP), 4-(10-phenyl-9-anthryl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBAPA), N,N''-(2-tert-butylanthracene-9,10-diyl-di-4,1-phenylene)bis(N,N',N'-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-carbazol-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,9-diphenyl-9H-carbazol-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthryl)-N,N’,N’-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(biphenyl-2-yl)-2-anthryl]-N,N’,N’-triphenyl-1,4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(biphenyl-2-yl)-N-[4-(9H-carbazol-9-yl)phenyl]-N-phenylanthracen-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (abbreviation: DPhAPhA), Coumarin 545T, N,N’-diphenylquinacridone (abbreviation: DPQd), Rubrene, 5,12-bis(biphenyl-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-ylidene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N’,N’-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N’,N’-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 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]quinolizin-9-yl)ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: BisDCJTM), N,N’-diphenyl-N,N’-(1,6-pyrenediyl)bis[(6-phenylbenzo[b]naphtho[1,2-d]furan)-8-amine] (abbreviation: 1,6BnfAPrn-03), N,N’-diphenyl-N,N’-bis(9-phenyl-9H-carbazol-2-yl)naphtho[2,3-b;6,7-b’]bisbenzofuran-3,10-diamine (abbreviation: 3,10PCA2Nbf(IV)-02), 3,10-bis[N-(dibenzofuran-3-yl)-N-phenylamino]naphtho[2,3-b;6,7-b’]bisbenzofuran (abbreviation: 3,10FrA2Nbf(IV)-02), etc. are mentioned. In particular, condensed aromatic diamine compounds typified by pyrene diamine compounds such as 1,6FLPAPrn, 1,6mMemFLPAPrn, and 1,6BnfAPrn-03 are preferable because they have high hole trapping properties and are excellent in light emission efficiency or reliability.,

[0122] Also, 5,9-diphenyl-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (abbreviation: DABNA1), 9-(biphenyl-3-yl)-N,N,5,11-tetraphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborine-3-amine (abbreviation: DABNA2), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-N,N-diphenyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborine-7-amine (abbreviation: DPhA-tBu4DABNA), 2,12-di(tert-butyl)-N,N,5,9-tetra(4-tert-butylphenyl)-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborine-7-amine (abbreviation: tBuDPhA-tBu4DABNA), 2,12-di(tert-butyl)-5,9-di(4-tert-butylphenyl)-7-methyl-5H,9H-[1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: Me-tBu4DABNA), N 7 ,N 7 ,N 13 ,N 13 ,5,9,11,15-octaphenyl-5H,9H,11H,15H-[1,4]benzazaborino[2,3,4-kl][1,4]benzazaborino[4’,3’,2’:4,5][1,4]benzazaborino[3,2-b]phenazaborine-7,13-diamine (abbreviation: ν-DABNA), 2-(4-tert-butylphenyl)benzo[5,6]indolo[3,2,1-jk]benzo[b]carbazole (abbreviation: tBuPBibc) and other condensed heteroaromatic compounds containing nitrogen and boron, especially compounds having a diaza-boranaphtho-anthracene skeleton, can be preferably used because they can obtain blue light emission with a narrow emission spectrum width and good color purity.

[0123] In addition to these, 9,10,11-tris[3,6-bis(1,1-dimethylethyl)-9H-carbazol-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3’,2’,1’:8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-G), 9,11-bis[3,6-bis(1,1-dimethylethyl)-9H-carbazol-9-yl]-2,5,15,18-tetrakis(1,1-dimethylethyl)indolo[3,2,1-de]indolo[3’,2’,1’:8,1][1,4]benzazaborino[2,3,4-kl]phenazaborine (abbreviation: BBCz-Y), etc. can be preferably used.

[0124] In the light-emitting layer 113 of the light-emitting device according to one aspect of the present invention, as the phosphorescent material that can be used as the light-emitting central substance, for example, those having an inner product of vector A and vector B of 2.5 or more, preferably 4.0 or more, can be used among the following. Also, among the phosphorescent materials other than those described below, those having an inner product of vector A and vector B of 2.5 or more, preferably 4.0 or more, can also be used.

[0125] Tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: [Ir(mpptz-dmp) 3 )), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviation: [Ir(Mptz) 3 ), such organometallic iridium complexes having a 4H-triazole skeleton, 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) such as an organometallic iridium complex having a 1H-triazole skeleton, fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium(III) (abbreviation: [Ir(iPrpim) 3 ) tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium(III) (abbreviation: [Ir(dmpimpt-Me) 3 ) organometallic iridium complexes having an imidazole skeleton such as tris(2-{1-[2,6-bis(1-methylethyl)phenyl]-1H-imidazol-2-yl-κN3}-4-cyanophenyl-κC)iridium(III) (abbreviation: CNImIr), tris[(6-tert-butyl-3-phenyl-2H-imidazo[4,5-b]pyrazin-1-yl-κC2)phenyl-κC]iridium(III) (abbreviation: [Ir(cb) 3 ) organometallic complexes having a benzimidazoliden skeleton such as bis[2-(4’,6’-difluorophenyl)pyridinato-N,C 2’ iridium(III) tetrakis(1-pyrazolyl)borate (abbreviation: FIr6), bis[2-(4’,6’-difluorophenyl)pyridinato-N,C 2’ iridium(III) picolinate (abbreviation: FIrpic), bis{2-[3’,5’-bis(trifluoromethyl)phenyl]pyridinato-N,C 2’}iridium(III) picolinate (abbreviation: [Ir(CF 3 ppy) 2 (pic)]), bis[2-(4’,6’-difluorophenyl)pyridinato-N,C 2’ iridium(III) acetylacetonate (abbreviation: FIrracac) and other organometallic iridium complexes having a phenylpyridine derivative having an electron-withdrawing group as a ligand. These are compounds that exhibit blue phosphorescent emission and have an emission peak in the wavelength range from 450 nm to 520 nm.

[0126] 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)]), (Acetylacetonato)bis[6-(2-norbornyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(nbppm) 2 (acac)]), (Acetylacetonato)bis[5-methyl-6-(2-methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: [Ir(mpmppm) 2 (acac)]), (Acetylacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: [Ir(dppm) 2 (acac)]), organometallic iridium complexes having a pyrimidine skeleton such as (Acetylacetonato)bis(3,5-dimethyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-Me) 2 (acac)]), (Acetylacetonato)bis(5-isopropyl-3-methyl-2-phenylpyrazinato)iridium(III) (abbreviation: [Ir(mppr-iPr) 2 (acac)]), organometallic iridium complexes having a pyrazine skeleton such as Tris(2-phenylpyridinato-N,C 2’ ) iridium(III) (abbreviation: [Ir(ppy) 3 ), Bis(2-phenylpyridinato-N,C 2’ ) iridium(III) acetylacetonate (abbreviation: [Ir(ppy) 2 (acac)]), Bis(benzo[h]quinolinato)iridium(III) acetylacetonate (abbreviation: [Ir(bzq) 2 (acac)]), Tris(benzo[h]quinolinato)iridium(III) (abbreviation: [Ir(bzq) 3) Tris(2-phenylquinolinato-N,C 2’ ) iridium(III) (abbreviation: [Ir(pq) 3 ) Bis(2-phenylquinolinato-N,C 2’ ) iridium(III) acetylacetonate (abbreviation: [Ir(pq) 2 (acac)]), [2-d3-methyl-8-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(5-d3-methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d 3 ) 2 (mbfpypy-d 3 )]), {2-(methyl-d 3 )-8-[4-(1-methylethyl-1-d)-2-pyridinyl-κN]benzofuro[2,3-b]pyridin-7-yl-κC}bis{5-(methyl-d 3 )-2-[5-(methyl-d 3 )-2-pyridinyl-κN]phenyl-κC}iridium(III) (abbreviation: [Ir(5mtpy-d 6 ) 2 (mbfpypy-iPr-d 4 )]), [2-d3-methyl-(2-pyridinyl-κN)benzofuro[2,3-b]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) 2 (mbfpypy-d 3 )]), [2-(4-methyl-5-phenyl-2-pyridinyl-κN)phenyl-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) 2 (mdppy)]), [2-(4-d 3 -methyl-5-phenyl-2-pyridinyl-κN2)phenyl-κC]bis[2-(5-d 3 -methyl-2-pyridinyl-κN2)phenyl-κC]iridium(III) (abbreviation: [Ir(5mppy-d3) 2 (mdppy-d 3)]), [2-Methyl-(2-pyridinyl-κN)benzo[b]naphtho[2,3-d]pyridine-κC]bis[2-(2-pyridinyl-κN)phenyl-κC]iridium(III) (abbreviation: [Ir(ppy) 2 (mbfpypy)]), in addition to organometallic iridium complexes having a pyridine skeleton such as tris(acetylacetonato)(monophenanthroline)terbium(III) (abbreviation: [Tb(acac) 3 (Phen)]). These are mainly compounds that exhibit green phosphorescent emission and have an emission peak in the wavelength range from 500 nm to 600 nm. In addition, organometallic iridium complexes having a pyrimidine skeleton are particularly preferred because they are also remarkably excellent in reliability or luminescence efficiency.

[0127] Also, (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(naphthalen-1-yl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: [Ir(d1npm) 2 (dpm)]) and other organometallic iridium complexes having a pyrimidine skeleton, (acetylacetonato)bis(2,3,5-triphenylpyrazinato)iridium(III) (abbreviation: [Ir(tppr) 2 (acac)]), bis(2,3,5-triphenylpyrazinato)(dipivaloylmethanato)iridium(III) (abbreviation: [Ir(tppr) 2 (dpm)]), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato]iridium(III) (abbreviation: [Ir(Fdpq) 2 (acac)]) and other organometallic iridium complexes having a pyrazine skeleton, 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-κC]iridium(III), in addition to organometallic iridium complexes having a pyridine skeleton, platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (abbreviation: PtOEP), tris(1,3-diphenyl-1,3-propanedionato)(monophenanthroline)europium(III) (abbreviation: [Eu(DBM) 3 (Phen)]), tris[1-(2-thenoyl)-3,3,3-trifluoroacetonato](monophenanthroline)europium(III) (abbreviation: [Eu(TTA) 3 (Phen)]) and other rare earth metal complexes. These are compounds that exhibit red phosphorescent emission and have an emission peak in the wavelength range from 600 nm to 700 nm. In addition, organometallic iridium complexes having a pyrazine skeleton can obtain red emission with good chromaticity.

[0128] In addition, among the phosphorescent materials other than those described above, those having an inner product of vector A and vector B of 2.5 or more, preferably 4.0 or more, can also be used.

[0129] In the light-emitting layer 113 of the light-emitting device according to one aspect of the present invention, as the TADF material that can be used as the light-emitting central substance, for example, those having an inner product of vector A and vector B of 2.5 or more, preferably 4.0 or more, can be used from among the following. In addition, among the TADF materials other than those described below, those having an inner product of vector A and vector B of 2.5 or more, preferably 4.0 or more, can also be used.

[0130] As the TADF material, 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), etc. can be mentioned. Examples of the metal-containing porphyrin include protoporphyrin-tin fluoride complex (SnF 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)), etioporphyrin-tin fluoride complex (SnF 2 (Etio I)), octaethylporphyrin-platinum chloride complex (PtCl 2 OEP), etc. can also be mentioned.

[0131]

Chemical formula

[0132] In addition, 2-(biphenyl-4-yl)-4,6-bis(12-phenylindolo[2,3-a]carbazol-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 9-(4,6-diphenyl-1,3,5-triazin-2-yl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: PCCzTzn), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 2-[4-(10H-phenoxazin-10-yl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5-phenyl-5,10-dihydrophenazin-10-yl)phenyl]-4,5-diphenyl-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl-9H-acridin-10-yl)-9H-xanthen-9-one (abbreviation: ACRXTN), bis[4-(9,9-dimethyl-9,10-dihydroacridine)phenyl]sulfone (abbreviation: DMAC-DPS), 10-phenyl-10H,10'H-spiro[acridine-9,9'-anthracene]-10'-one (abbreviation: ACRSA), and other heterocyclic compounds having one or both of a π-electron-excessive heteroaromatic ring and a π-electron-deficient heteroaromatic ring can also be used. Since the heterocyclic compound has a π-electron-excessive heteroaromatic ring and a π-electron-deficient heteroaromatic ring, it has both high electron transportability and hole transportability, which is preferable. Among them, among the skeletons having a π-electron-deficient heteroaromatic ring, a pyridine skeleton, a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), and a triazine skeleton are preferable because they are stable and have good reliability. In particular, a benzofuropyrimidine skeleton, a benzothienopyrimidine skeleton, a benzofuropyrazine skeleton, and a benzothienopyrazine skeleton are preferable because they have high acceptor properties and good reliability. Also, among the skeletons having a π-electron-excessive heteroaromatic ring, an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton are stable and have good reliability, so it is preferable to have at least one of these skeletons.Note that as the furan skeleton, a dibenzofuran skeleton is preferable, and as the thiophene skeleton, a dibenzothiophene skeleton is preferable. Further, as the pyrrole skeleton, an indole skeleton, a carbazole skeleton, an indolocarbazole skeleton, a bicarbazole skeleton, and a 3-(9-phenyl-9H-carbazol-3-yl)-9H-carbazole skeleton are particularly preferable. Note that a substance in which a π-electron-excessive heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded has both the electron-donating property of the π-electron-excessive heteroaromatic ring and the electron-accepting property of the π-electron-deficient heteroaromatic ring enhanced, and S. 1 Level and T 1 Since the energy difference between the levels becomes small, it is particularly preferable because thermally activated delayed fluorescence can be efficiently obtained. Note that instead of the π-electron-deficient heteroaromatic ring, an aromatic ring to which an electron-withdrawing group such as a cyano group is bonded may be used. Further, as the π-electron-excessive skeleton, an aromatic amine skeleton, a phenazine skeleton, etc. can be used. Further, as the π-electron-deficient skeleton, a xanthene skeleton, a thioxanthene dioxide skeleton, an oxadiazole skeleton, a triazole skeleton, an imidazole skeleton, an anthraquinone skeleton, a boron-containing skeleton such as phenylborane and boranthene, an aromatic ring having a nitrile group or a cyano group such as benzonitrile or cyanobenzene, a heteroaromatic ring, a carbonyl skeleton such as benzophenone, a phosphine oxide skeleton, a sulfone skeleton, etc. can be used. Thus, a π-electron-deficient skeleton and a π-electron-excessive skeleton can be used instead of at least one of the π-electron-deficient heteroaromatic ring and the π-electron-excessive heteroaromatic ring.

[0133]

Chemical formula

[0134] Note that the TADF material is S 1 Level and T 1It is a material having a function of converting energy from triplet excitation energy to singlet excitation energy with a small difference from the level and by reverse intersystem crossing. Therefore, upconversion (reverse intersystem crossing) from triplet excitation energy to singlet excitation energy is possible with a small amount of thermal energy, and a singlet excited state can be efficiently generated. In addition, triplet excitation energy can be converted into light emission.

[0135] In addition, an exciplex (also referred to as an exciplex, exiplex or exciplex) that forms an excited state with two types of substances has an S 1 level and a T 1 level with an extremely small difference, and has a function as a TADF material capable of converting triplet excitation energy into singlet excitation energy.

[0136] Note that, as an index of the T 1 level, a phosphorescence spectrum observed at low temperature (for example, from 77K to 10K) may be used. As a TADF material, a tangent is drawn at the trailing edge on the short wavelength side of its fluorescence spectrum, and the energy of the wavelength of the extrapolated line is defined as the S 1 level, and a tangent is drawn at the trailing edge on the short wavelength side of the phosphorescence spectrum, and the energy of the wavelength of the extrapolated line is defined as the T 1 level. When the difference between the S 1 and the T 1 is preferably 0.3 eV or less, and more preferably 0.2 eV or less.

[0137] In addition, when a TADF material is used as a light-emitting substance, the S 1 level of the host material is preferably higher than the S 1 level of the TADF material. Also, the T 1 level of the host material is preferably higher than the T 1 level of the TADF material.

[0138] As the host material of the light-emitting layer, various carrier transport materials such as a material having electron transporting properties and / or a material having hole transporting properties, and the above TADF material can be used.

[0139] As materials having hole transporting properties, various organic compounds such as aromatic amine compounds, heteroaromatic compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. Note that as the substance having hole transporting properties used in the composite material, it is preferably a substance having a hole mobility of 1×10 -6 cm 2 / Vs or more. Further, as the material having hole transporting properties, organic compounds having an amine skeleton or a π-electron excess type heteroaromatic ring skeleton are preferable. As the π-electron excess type heteroaromatic ring, a condensed aromatic ring containing at least one of an acridine skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a furan skeleton, a thiophene skeleton, and a pyrrole skeleton in the ring is preferable. Specifically, a carbazole ring, a dibenzothiophene ring, or a ring further condensed with an aromatic ring or a heteroaromatic ring thereto is preferable.

[0140] As such an organic compound having hole transporting properties, it is more preferable to have any of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton. In particular, it may be an aromatic amine having a substituent containing 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. Note that it is preferable that these organic compounds having hole transporting properties are substances having an N,N-bis(4-biphenyl)amino group because a light-emitting device with good lifetime can be fabricated.

[0141] Examples of such organic compounds include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-4,4'-diaminobiphenyl (abbreviation: TPD), N,N'-bis(9,9'-spirobi[9H-fluorene]-2-yl)-N,N'-diphenyl-4,4'-diaminobiphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''-(9-phenyl-9H-carbazol-3-yl)triphenylamine (abbreviation: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]fluorene-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9'-spirobi[9H-fluorene]-2-amine (abbreviation: PCBASF), and other compounds having an aromatic amine skeleton, 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), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviation: PCCP), 3,9-bis(9-phenyl-9H-carbazol-3-yl)-9H-carbazole (abbreviation: PCCzPC), 9-(biphenyl-4-yl)-9'-phenyl-3,3'-bi-9H-carbazole (abbreviation: PCCzBP), 9,9'-bis(biphenyl-4-yl)-3,3'-bi-9H-carbazole (abbreviation: BisBPCz), 9,9'-bis(biphenyl-3-yl)-3,3'-Bi-9H-carbazole (abbreviation: BismBPCz), 9-(biphenyl-3-yl)-9'-(biphenyl-4-yl)-9H,9'H-3,3'-bicarbazole (abbreviation: mBPCCBP), 9-(2-naphthyl)-9'-phenyl-9H,9'H-3,3'-bicarbazole (abbreviation: βNCCP), 9-(3-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCmBP), 9-(4-biphenyl)-9'-(2-naphthyl)-3,3'-bi-9H-carbazole (abbreviation: βNCCBP), 9,9'-di-2-naphthyl-3,3'-9H,9'H-bicarbazole (abbreviation: BisβNCz), 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-3-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-5'-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':4',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, 9-(2-naphthyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-phenyl-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole (abbreviation: PCCzTp), 9,9'-bis(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(4-biphenyl)-9'-(triphenylene-2-yl)-3,3'-9H,9'H-bicarbazole, 9-(triphenylene-2-yl)-9'-[1,1':3',1''-terphenyl]-4-yl-3,3'-9H,9'H-bicarbazole, N,N-bis(9,9-dimethyl-9H-fluoren-2-yl)-9,9'-spirobi-9H-fluorene-1-amine, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz), 9'-phenyl-9'H-9,3':6',Compounds having a carbazole skeleton such as 9’’-tercarbazole (abbreviation: PSiCzGI), 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: DBTFLP-III), compounds having a thiophene skeleton such as 4-[4-(9-phenyl-9H-fluoren-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), 4,4’,4’’-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviation: DBF3P-II), compounds having a furan skeleton such as 4-{3-[3-(9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviation: mmDBFFLBi-II), etc. Among those described above, compounds having an aromatic amine skeleton or a carbazole skeleton are preferable because they have good reliability, high hole transportability, and contribute to reducing the driving voltage. Also, the organic compounds exemplified as materials having hole transportability in the hole transport layer can also be used.,

[0142] As a material having electron transportability, a substance having an electron mobility with the square root of the electric field strength [V / cm] at 600 being 1×10 -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 / Vs or more is preferable. In addition, substances other than these can be used as long as they have higher electron transportability than holes.,

[0143] Examples of materials having electron transportability include, for example, bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation: BeBq 2) Metal complexes such as bis(2-methyl-8-quinolinolato)(4-phenylphenolato)aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolato]zinc(II) (abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolato]zinc(II) (abbreviation: ZnBTZ), and organic compounds having a π-electron-deficient heteroaromatic ring are preferred. Examples of the organic compounds having a π-electron-deficient heteroaromatic ring skeleton include organic compounds containing a heteroaromatic ring having an azole skeleton, organic compounds containing a heteroaromatic ring having a pyridine skeleton, organic compounds containing a heteroaromatic ring having a diazine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton.

[0144] Among them, organic compounds containing a heteroaromatic ring having a diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton), organic compounds containing a heteroaromatic ring having a pyridine skeleton, and organic compounds containing a heteroaromatic ring having a triazine skeleton are preferred because of their good reliability. In particular, organic compounds containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and organic compounds containing a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to reducing the driving voltage. In addition, benzofuropyrimidine skeleton, benzothienopyrimidine skeleton, benzofuropyrazine skeleton, and benzothienopyrazine skeleton are preferred because of their high acceptor properties and good reliability.

[0145] Examples of organic compounds having a π-electron-deficient heteroaromatic ring skeleton include, for example, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviation: CO11), 2,2’,2’’-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBIm-II), 4,4’-bis(5-methylbenzoxazol-2-yl)stilbene (abbreviation: BzOs) and other organic compounds having an azole skeleton, 3,5-bis[3-(9H-carbazol-9-yl)phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridyl)phenyl]benzene (abbreviation: TmPyPB), bathophenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: BCP), 2,9-di(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen), 2,2’-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P), 2-[3-(2-triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: mTpPPhen), 2-phenyl-9-(2-triphenylenyl)-1,10-phenanthroline (abbreviation: Ph-TpPhen), 2-[4-(9-phenanthrenyl)-1-naphthalenyl]-1,10-phenanthroline (abbreviation: PnNPhen), 2-[4-(2-triphenylenyl)phenyl]-1,10-phenanthroline (abbreviation: pTpPPhen) and other organic compounds containing a heteroaromatic ring having a pyridine skeleton, 2-[3-(dibenzothiophen-4-yl)phenyl]dibenzof,h]Quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3’-(Dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3’-(9H-Carbazol-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 2-[4’-(9-Phenyl-9H-carbazol-3-yl)-3,1’-biphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mpPCBPDBq), 2-[4-(3,6-Diphenyl-9H-carbazol-9-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDBTPDBq-II), 6-[3-(Dibenzothiophen-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 9-[3’-(Dibenzothiophen-4-yl)biphenyl-3-yl]naphtho[1’,2’:4,5]furo[2,3-b]pyrazine (abbreviation: 9mDBtBPNfpr), 9-[3’-(Dibenzothiophen-4-yl)biphenyl-4-yl]naphtho[1’,2’:4,5]furo[2,3-b]pyrazine (abbreviation: 9pmDBtBPNfpr), 4,6-Bis[3-(phenanthren-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-Bis[3-(dibenzothiophen-4-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6-Bis[3-(9H-carbazol-9-yl)phenyl]pyrimidine (abbreviation: 4,6mCzP2Pm), 9,9’-[Pyrimidine-4,6-diylbis(biphenyl-3,3’-diyl)]bis(9H-carbazole) (abbreviation: 4,6mCzBP2Pm), 8-(Biphenyl-4-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8BP-4mDBtPBfpm), 3,8-Bis[3-(dibenzothiophen-4-yl)phenyl]benzofuro[2,3-b]pyrazine (abbreviation: 3,8mDBtP2Bfpr), 4,8-Bis[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 4,8mDBtP2Bfpm), 8-[3'-(Dibenzothiophen-4-yl)(biphenyl-3-yl)]naphtho[1',2':4,5]furo[3,2-d]pyrimidine (abbreviation: 8mDBtBPNfpm), 8-[(2,2'-Binaphthalen)-6-yl]-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8(βN2)-4mDBtPBfpm), 2,2'-(Pyridine-2,6-diyl)bis(4-phenylbenzo[h]quinazoline) (abbreviation: 2,6(P-Bqn)2Py), 2,2'-(Pyridine-2,6-diyl)bis{4-[4-(2-naphthyl)phenyl]-6-phenylpyrimidine} (abbreviation: 2,6(NP-PPm)2Py), 6-(Biphenyl-3-yl)-4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenylpyrimidine (abbreviation: 6mBP-4Cz2PPm), 2,6-bis(4-naphthalen-1-ylphenyl)-4-[4-(3-pyridyl)phenyl]pyrimidine (abbreviation: 2,4NP-6PyPPm), 4-[3,5-bis(9H-carbazol-9-yl)phenyl]-2-phenyl-6-(biphenyl-4-yl)pyrimidine (abbreviation: 6BP-4Cz2PPm), 7-[4-(9-phenyl-9H-carbazol-2-yl)quinazolin-2-yl]-7H-dibenzo[c,g]carbazole (abbreviation: PC-cgDBCzQz), 8-(1,1′:4′,1′′-Terphenyl-3-yl)-4-[3-(dibenzothiophen-4-yl)phenyl]-[1]benzofuro[3,2-d]pyrimidine (abbreviation: 8mpTP-4mDBtPBfpm), and other organic compounds having a diazine skeleton, 2-(Biphenyl-4-yl)-4-phenyl-6-(9,9'-spirobi[9H-fluorene]-2-yl)-1,3,5-triazine (abbreviation: BP-SFTzn), 2-{3-[3-(Benzo[b]naphtho[1,2-d]furan-8-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mBnfBPTzn), 2-{3-[3-(Benzo[b]naphtho[1,2-d]furan-6-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-Triazine (abbreviation: mBnfBPTzn-02), 2-{4-[3-(N-Phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn), 9-[3-(4,6-Diphenyl-1,3,5-triazin-2-yl)phenyl]-9’-phenyl-2,3’-bi-9H-carbazole (abbreviation: mPCCzPTzn-02), 2-[3’-(9,9-Dimethyl-9H-fluoren-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mFBPTzn), 5-[3-(4,6-Diphenyl-1,3,5-triazin-2-yl)phenyl]-7,7-dimethyl-5H,7H-inden[2,1-b]carbazole (abbreviation: mINc(II)PTzn), 2-{3-[3-(Dibenzothiophen-4-yl)phenyl]phenyl}-4,6-diphenyl-1,3,5-triazine (abbreviation: mDBtBPTzn), 2,4,6-Tris[3’-(pyridin-3-yl)biphenyl-3-yl]-1,3,5-triazine (abbreviation: TmPPPyTz), 2-[3-(2,6-Dimethyl-3-pyridinyl)-5-(9-phenanthrenyl)phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mPn-mDMePyPTzn), 11-[4-(Biphenyl-4-yl)-6-phenyl-1,3,5-triazin-2-yl]-11,12-dihydro-12-phenyl-indolo[2,3-a]carbazole (abbreviation: BP-Icz(II)Tzn), 2-[3’-(Triphenylene-2-yl)biphenyl-3-yl]-4,6-diphenyl-1,3,5-triazine (abbreviation: mTpBPTzn), 3-[9-(4,6-Diphenyl-1,3,5-triazin-2-yl)-2-dibenzofuranyl]-9-phenyl-9H-carbazole (abbreviation: PCDBfTzn), 2-(Biphenyl-3-yl)-4-phenyl-6-{8-[(1,1’:4’,1’’-terphenyl)-4-yl]-1-dibenzofuranyl}-1,3,5-triazine (abbreviation: mBP-TPDBfTzn), 2-[4-(2-Naphthalenyl)phenyl]-4-phenyl-6-spiro[9H-fluorene-9,9’-[9H]xanthene]-4-yl-1,3,5 - triazine (abbreviation: βNP - SFx(4)Tzn), 9,9’ - {6 - [3 - (triphenylsilyl)phenyl] - 1,3,5 - triazine - 2,4 - diyl}bis(9H - carbazole) (abbreviation: SiTrzCz2), 2 - phenyl - 4,6 - bis[3 - (triphenylsilyl)phenyl] - 1,3,5 - triazine (abbreviation: mSiTrz), 11 - [4 - (biphenyl - 4 - yl) - 6 - phenyl - 1,3,5 - triazine - 2 - yl] - 11,12 - dihydro - 12 - (biphenyl - 3 - yl)indolo[2,3 - a]carbazole (abbreviation: BP - mBPIcz(II)Tzn), 3 - {3 - [9 - (4,6 - diphenyl - 1,3,5 - triazine - 2 - yl) - 2 - dibenzofuranyl]phenyl} - 9 - phenyl - 9H - carbazole (abbreviation: mPCPDBfTzn), 9,9’ - [6 - (biphenyl - 4 - yl) - 2 - phenyl - 1,3,5 - triazine - 4,3’’ - diyl]bis(9H - carbazole) (abbreviation: Cz - pmCzBPTzn), 3 - phenyl - 9 - [4 - phenyl - 6 - (9 - phenyl - 3 - dibenzofuranyl) - 1,3,5 - triazine - 2 - yl] - 9H - carbazole (abbreviation: PDBf - PCzTzn), 9 - [4 - (4,6 - diphenyl - 1,3,5 - triazine - 2 - yl) - 2 - dibenzothienyl] - 2 - phenyl - 9H - carbazole (abbreviation: PCzDBtTzn) and other organic compounds containing a heteroaromatic ring having a triazine skeleton can be mentioned. Further, an organic compound containing a heteroaromatic ring having a diazine skeleton or an organic compound containing a heteroaromatic ring having a pyridine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton are preferable because of their good reliability. In particular, an organic compound containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound containing a heteroaromatic ring having a triazine skeleton have high electron transport properties and contribute to the reduction of driving voltage.,

[0146] In addition, bipolar organic compounds such as 3,6-bis(diphenylamino)-9-[4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-9H-carbazole (abbreviation: DACT-II) and 2-{3-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol-9-yl]phenyl}dibenzof[h]quinoxaline (abbreviation: 2mPCCzPDBq) can also be used.

[0147] As the TADF materials that can be used as the host material, those listed as TADF materials above can be used in the same way. When a TADF material is used as the host material, the triplet excitation energy generated in the TADF material is converted into singlet excitation energy by reverse intersystem crossing, and further energy transfer to the luminescent substance can increase the luminous efficiency of the light-emitting device. At this time, the TADF material functions as an energy donor, and the luminescent substance functions as an energy acceptor.

[0148] This is very effective when the above luminescent substance is a fluorescent luminescent substance. Also, at this time, in order to obtain high luminous efficiency, the S 1 level of the TADF material is preferably higher than the S 1 level of the fluorescent luminescent substance. Also, the T 1 level of the TADF material is preferably higher than the S 1 level of the fluorescent luminescent substance. Therefore, the T 1 level of the TADF material is preferably higher than the T 1 level of the fluorescent luminescent substance.

[0149] In addition, it is preferable to use a TADF material that exhibits luminescence overlapping with the wavelength of the absorption band on the lowest energy side of the fluorescent luminescent substance. By doing so, the transfer of excitation energy from the TADF material to the fluorescent luminescent substance becomes smooth, and light emission can be obtained efficiently, which is preferable.

[0150] In addition, in order for singlet excited energy to be efficiently generated from triplet excited energy by reverse intersystem crossing, it is preferable that carrier recombination occurs in the TADF material. Further, it is preferable that the triplet excited energy generated in the TADF material does not transfer to the triplet excited energy of the fluorescent substance. For this purpose, it is preferable that the fluorescent substance has a protecting group around the luminophore (skeleton causing luminescence) of the fluorescent substance. As the protecting group, a substituent having no π bond is preferable, a saturated hydrocarbon is preferable, and specifically, an alkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and a trialkylsilyl group having 3 to 10 carbon atoms can be mentioned. It is more preferable that there are a plurality of protecting groups. Since a substituent having no π bond has a poor function of transporting carriers, it is possible to increase the distance between the TADF material and the luminophore of the fluorescent substance with little influence on carrier transport or carrier recombination. Here, the luminophore refers to an atomic group (skeleton) that causes luminescence in the fluorescent substance. The luminophore preferably has a skeleton having a π bond, preferably contains an aromatic ring, and preferably has a condensed aromatic ring or a condensed heteroaromatic ring. Examples of such a luminophore include a phenanthrene skeleton, a stilbene skeleton, an acridone skeleton, a phenoxazine skeleton, a phenothiazine skeleton, a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, a naphthobisbenzofuran skeleton, and the like. In particular, fluorescent substances having a naphthalene skeleton, an anthracene skeleton, a fluorene skeleton, a chrysene skeleton, a triphenylene skeleton, a tetracene skeleton, a pyrene skeleton, a perylene skeleton, a coumarin skeleton, a quinacridone skeleton, or a naphthobisbenzofuran skeleton are preferable because they have a high fluorescence quantum yield.

[0151] When using a fluorescent emitting substance as the light-emitting center substance, as the host material, a material having an acene skeleton, particularly an anthracene skeleton, is suitable. When using a substance having an anthracene skeleton as the host material of the fluorescent emitting substance, it is possible to realize a light-emitting layer with both good luminous efficiency and durability. As the substance having an anthracene skeleton used as the host material, a substance having a diphenylanthracene skeleton, particularly a substance having a 9,10-diphenylanthracene skeleton, is preferable because it is chemically stable. Further, when the host material has a carbazole skeleton, it is preferable because the hole injection and transport properties are enhanced. However, when it contains a benzocarbazole skeleton in which a benzene ring is further condensed with carbazole, the HOMO level is about 0.1 eV higher than that of the carbazole skeleton, and holes are more likely to enter, so it is more preferable. In particular, when the host material contains a dibenzocarbazole skeleton, the HOMO level is about 0.1 eV higher than that of the carbazole skeleton, holes are more likely to enter, the hole transport property is excellent, and the heat resistance is also high, so it is suitable. Therefore, a substance having both a 9,10-diphenylanthracene skeleton and a carbazole skeleton (or a benzocarbazole skeleton or a dibenzocarbazole skeleton) is more preferable as the host material. From the above viewpoint of hole injection and transport properties, a benzofluorene skeleton or a dibenzofluorene skeleton may be used instead of the carbazole skeleton.

[0152] Examples of such substances include 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (abbreviation: PCzPA), 3-[4-(1-naphthyl)phenyl]-9-phenyl-9H-carbazole (abbreviation: PCPN), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), 7-[4-(10-phenyl-9-anthryl)phenyl]-7H-dibenzo[c,g]carbazole (abbreviation: cgDBCzPA), 6-[3-(9,10-diphenyl-2-anthryl)phenyl]benzo[b]naphtho[1,2-d]furan (abbreviation: 2mBnfPPA), 9-phenyl-10-[4-(9-phenyl-9H-fluoren-9-yl)biphenyl-4'-yl]anthracene (abbreviation: FLPPA), 9-(1-naphthyl)-10-[4-(2-naphthyl)phenyl]anthracene (abbreviation: αN-βNPAnth), 9-(1-naphthyl)-10-(2-naphthyl)anthracene (abbreviation: α,βADN), 2-(10-phenylanthracen-9-yl)dibenzofuran, 2-(10-phenyl-9-anthracenyl)benzo[b]naphtho[2,3-d]furan (abbreviation: Bnf(II)PhA), 9-(2-naphthyl)-10-[3-(2-naphthyl)phenyl]anthracene (abbreviation: βN-mβNPAnth), 1-{4-[10-(biphenyl-4-yl)-9-anthracenyl]phenyl}-2-ethyl-1H-benzimidazole (abbreviation: EtBImPBPhA), and the like. In particular, CzPA, cgDBCzPA, 2mBnfPPA, and PCzPA exhibit very good properties, so they are preferred choices.

[0153] Note that the host material may be a material obtained by mixing multiple substances. When using a mixed host material, it is preferable to mix a material having electron transporting properties and a material having hole transporting properties. By mixing a material having electron transporting properties and a material having hole transporting properties, the transport properties of the light-emitting layer 113 can be easily adjusted, and the control of the recombination region can also be conveniently performed. The weight ratio of the content of the material having hole transporting properties to the material having electron transporting properties may be Hole transporting material: Electron transporting material = 1:19 to 19:1.

[0154] In addition, as a part of the above mixed materials, a phosphorescent substance can be used. The phosphorescent substance can be used as an energy donor that supplies excitation energy to the fluorescent substance when the fluorescent substance is used as the luminescent substance.

[0155] Also, an exciplex may be formed between these mixed materials. By selecting a combination that forms an exciplex that emits light so as to overlap with the wavelength of the absorption band on the lowest energy side of the luminescent substance, energy transfer becomes smooth and light emission can be obtained efficiently, which is preferable. In addition, since the driving voltage is also reduced by using this configuration, it is preferable.

[0156] Note that at least one of the materials forming the exciplex may be a phosphorescent substance. By doing so, the triplet excitation energy can be efficiently converted into singlet excitation energy by reverse intersystem crossing.

[0157] As a combination of materials that efficiently form an exciplex, it is preferable that the HOMO level of the hole-transporting material is higher than the HOMO level of the electron-transporting material. Also, it is preferable that the LUMO level of the hole-transporting material is higher than the LUMO level of the electron-transporting material. Note that the LUMO level and HOMO level of the material can be derived from the electrochemical characteristics (reduction potential and oxidation potential) of the material measured by cyclic voltammetry (CV) measurement.

[0158] Note that the formation of an exciplex can be confirmed, for example, by comparing the emission spectra of a material having hole-transporting properties, the emission spectra of a material having electron-transporting properties, and the emission spectra of a mixed film obtained by mixing these materials, and observing the phenomenon that the emission spectrum of the mixed film is shifted to a longer wavelength (or has a new peak on the longer wavelength side) than the emission spectra of the respective materials. Alternatively, the transient photoluminescence (PL) of a material having hole-transporting properties, the transient PL of a material having electron-transporting properties, and the transient PL of a mixed film obtained by mixing these materials are compared, and the formation of the exciplex can be confirmed by observing differences in transient responses such as that the transient PL lifetime of the mixed film has a longer-lived component or the ratio of the delayed component is increased compared to the transient PL lifetimes of the respective materials. Further, the above-mentioned transient PL may be read as transient electroluminescence (EL). That is, by comparing the transient EL of a material having hole-transporting properties, the transient EL of a material having electron-transporting properties, and the transient EL of a mixed film thereof, and observing differences in transient responses, the formation of the exciplex can also be confirmed.

[0159] The electron transport layer 114 is a layer containing a substance having electron-transporting properties. As the substance having electron-transporting properties, a substance having an electron mobility with the square root of the electric field strength [V / cm] at 600 being 1×10 -7 cm 2 / Vs or more, preferably 1×10 -6 cm 2 / Vs or more is preferred. Note that, as long as the substance has higher electron-transporting properties than hole-transporting properties, other substances can be used. As the above-mentioned organic compound, an organic compound having a π-electron-deficient heteroaromatic ring is preferred. As the organic compound having a π-electron-deficient heteroaromatic ring, for example, it is preferably any one or more of 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.

[0160] As the organic compound that can be used for the electron transport layer 114, those exemplified as the materials having electron transporting properties that can be used for the host material of the light emitting layer 113 can be used in the same manner. Among them, an organic compound containing a heteroaromatic ring having a diazine skeleton or an organic compound containing a heteroaromatic ring having a pyridine skeleton, and an organic compound containing a heteroaromatic ring having a triazine skeleton are preferable because of their good reliability. In particular, an organic compound containing a heteroaromatic ring having a diazine (pyrimidine or pyrazine) skeleton and an organic compound containing a heteroaromatic ring having a triazine skeleton have high electron transporting properties and contribute to reducing the driving voltage. In particular, organic compounds having a phenanthroline skeleton such as mTpPPhen, PnNPhen, and mPPhen2P are preferable, and organic compounds having a phenanthroline dimer structure such as mPPhen2P are more preferable because of their excellent stability.

[0161] Note that the electron transport layer 114 may have a stacked structure. Further, the layer in contact with the light emitting layer 113 in the electron transport layer 114 having a stacked structure may function as a hole blocking layer. When the electron transport layer in contact with the light emitting layer functions as a hole blocking layer, it is preferable to use a material whose HOMO level is 0.5 eV or more lower than the HOMO level of the material contained in the light emitting layer 113.

[0162] As the electron injection layer 115, it may be provided by a layer containing an alkali metal or an alkaline earth metal, a compound or complex of an alkali metal or an alkaline earth metal, or 1,1'-pyridine-2,6-diyl-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: hpp2Py). The electron injection layer 115 may be one in which these are contained in a layer made of a material having electron transporting properties.

[0163] Alternatively, a charge generation layer 116 may be provided instead of the electron injection layer 115 (FIG. 1(B)). The charge generation layer 116 is a layer that can inject holes into the layer in contact with the cathode side of the layer and electrons into the layer in contact with the anode side by applying a potential. The charge generation layer 116 includes at least a P-type layer 117. The P-type layer 117 is preferably formed using the composite material listed as the material that can constitute the above-mentioned hole injection layer 111. Further, the P-type layer 117 may be formed by laminating a film containing an acceptor material and a film containing a hole transport material as the materials constituting the composite material. By applying a potential to the P-type layer 117, electrons are injected into the electron transport layer 114 and holes are injected into the cathode, and the light-emitting device operates. Further, since the organic compound of one aspect of the present invention is an organic compound having a low refractive index, by using it for the P-type layer 117, a light-emitting device with good external quantum efficiency can be obtained.

[0164] In addition, it is preferable that either one or both of an electron relay layer 118 and an electron injection buffer layer 119 are provided in addition to the P-type layer 117 in the charge generation layer 116.

[0165] The electron relay layer 118 contains at least a substance having electron transport properties and has a function of preventing the interaction between the electron injection buffer layer 119 and the P-type layer 117 and smoothly transferring electrons. The LUMO level of the substance having electron transport properties contained in the electron relay layer 118 is preferably positioned between the LUMO level of the acceptor substance in the P-type layer 117 and the LUMO level of the substance contained in the layer in contact with the charge generation layer 116 in the electron transport layer 114. When the specific energy level of the LUMO level in the substance having electron transport properties used for the electron relay layer 118 is -5.0 eV or higher, preferably -5.0 eV or higher and -3.0 eV or lower, more preferably -4.30 eV or higher and -3.00 eV or lower, and even more preferably -4.30 eV or higher and -3.30 eV or lower, it is preferable because an increase in the driving voltage can be suppressed. Note that as the substance having electron transport properties used for the electron relay layer 118, it is preferable to use a phthalocyanine-based material or a metal complex having a metal-oxygen bond and an aromatic ligand.

[0166] As substances having electron transporting properties used in the electron relay layer 118, specifically, quinoxalino[2,3-a:2’,3’-c]phenazine (abbreviation: HATNA), 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2’,3’-c]phenazine (abbreviation: HATNA-F6), 3,4,9,10-perylenetetracarboxylic diimide (abbreviation: PTCDI), perylene tetracarboxylic acid derivatives such as 3,4,9,10-perylenetetracarboxyl-bis-benzimidazole (abbreviation: PTCBI), (C60-Ih)[5,6]fullerene (abbreviation: C60), (C70-D5h)[5,6]fullerene (abbreviation: C70) can be used. Further, a compound having a heterophane skeleton which is a cyclophane skeleton containing a heterocycle can be used, and as the compound, for example, phthalocyanine compounds such as phthalocyanine (abbreviation: H 2 Pc) etc. can be used. Also, metal phthalocyanines having copper, zinc, cobalt, iron, chromium, nickel, etc. such as copper phthalocyanine (abbreviation: CuPc), zinc phthalocyanine (abbreviation: ZnPc), cobalt phthalocyanine (abbreviation: CoPc), iron phthalocyanine (abbreviation: FePc), tin phthalocyanine (abbreviation: SnPc), tin oxide phthalocyanine (abbreviation: SnOPc), titanium oxide phthalocyanine (abbreviation: TiOPc), vanadium oxide phthalocyanine (abbreviation: VOPc) and their derivatives, etc. can be used. In particular, phthalocyanine-based metal complexes such as copper phthalocyanine or zinc phthalocyanine or 2,3,8,9,14,15-hexafluorodiquinoxalino[2,3-a:2’,3’-c]phenazine are preferable.

[0167] For the electron injection buffer layer 119, substances with high electron injection properties such as alkali metals, alkaline earth metals, rare earth metals, and their compounds (including alkali metal compounds (oxides such as lithium oxide, halides, carbonates such as lithium carbonate, cesium carbonate, etc.), alkaline earth metal compounds (including oxides, halides, carbonates), or rare earth metal compounds (including oxides, halides, carbonates)) can be used.

[0168] In addition, when the electron injection buffer layer 119 is formed by including a material having electron transporting properties and a donor substance, as the donor substance, in addition to alkali metals, alkaline earth metals, rare earth metals, and their compounds (including alkali metal compounds (oxides such as lithium oxide, halides, carbonates such as lithium carbonate and cesium carbonate), alkaline earth metal compounds (including oxides, halides, carbonates), or rare earth metal compounds (including oxides, halides, carbonates)), organic compounds such as tetrathianaphthacene (abbreviation: TTN), nickelocene, and decamethylnickelocene can also be used. Note that as the material having electron transporting properties, the same material as the material constituting the electron transport layer 114 described above can be used. Further, a layer including a strongly basic substance (such as 1,1'-pyridine-2,6-diyl-bis(1,3,4,6,7,8-hexahydro-2H-pyrimido[1,2-a]pyrimidine) (abbreviation: hpp2Py)) having an acid dissociation constant pKa of 8 or more and a material having electron transporting properties may be used.

[0169] The second electrode 102 is an electrode including a cathode. The second electrode 102 may have a laminated structure, and in that case, the layer in contact with the organic compound layer 103 functions as a cathode. As the material for forming the cathode, a metal, alloy, electrically conductive compound, and a mixture thereof having a small work function (specifically, 3.8 eV or less) can be used. Specific examples of such cathode materials include alkali metals such as lithium (Li) or cesium (Cs), elements belonging to Group 1 or Group 2 of the periodic table such as magnesium (Mg), calcium (Ca), and strontium (Sr), and alloys (MgAg, AlLi) and compounds (lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF 2) etc., rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing these are mentioned. However, by providing an electron injection layer 115 or a thin film of a material with a small work function between the second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, indium tin oxide containing silicon or silicon oxide, etc. can be used as the cathode regardless of the work function.

[0170] In addition, when the second electrode 102 is formed of a material having transparency to visible light, a light-emitting device that emits light from the second electrode 102 side can be obtained.

[0171] These conductive materials can be formed into a film using dry methods such as vacuum evaporation or sputtering, inkjet method, spin coating method, etc. Also, it may be formed by a wet method using the sol-gel method, or may be formed by a wet method using a paste of a metal material.

[0172] In addition, as a method for forming the organic compound layer 103, various methods can be used regardless of dry or wet methods. For example, vacuum evaporation method, gravure printing method, offset printing method, screen printing method, inkjet method or spin coating method, etc. may be used.

[0173] Also, each of the above-mentioned electrodes or layers may be formed using different film formation methods.

[0174] Subsequently, an embodiment of a light-emitting device having a structure in which a plurality of light-emitting units are stacked (also referred to as a stacked element or a tandem element) will be described with reference to FIG. 1(C). This light-emitting device is a light-emitting device having a plurality of light-emitting units between an anode and a cathode. One light-emitting unit has substantially the same configuration as the organic compound layer 103 shown in FIG. 1(A). That is, it can be said that the light-emitting device shown in FIG. 1(C) is a light-emitting device having a plurality of light-emitting units, and the light-emitting devices shown in FIG. 1(A) or FIG. 1(B) are light-emitting devices having one light-emitting unit.

[0175] In FIG. 1(C), a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between a first electrode 501 and a second electrode 502, and a charge generation layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The first electrode 501 and the second electrode 502 respectively correspond to the first electrode 101 and the second electrode 102 in FIG. 1(A), and the same ones as those described in the description of FIG. 1(A) can be applied. Also, the first light-emitting unit 511 and the second light-emitting unit 512 may have the same configuration or different configurations.

[0176] The charge generation layer 513 has a function of injecting electrons into one light-emitting unit and holes into the other light-emitting unit when a voltage is applied to the first electrode 501 and the second electrode 502. That is, in FIG. 1(C), when a voltage is applied so that the potential of the anode is higher than the potential of the cathode, the charge generation layer 513 may inject electrons into the first light-emitting unit 511 and holes into the second light-emitting unit 512.

[0177] The charge generation layer 513 is preferably formed with the same configuration as the charge generation layer 116 described in FIG. 1(B). Since the composite material of the organic compound and the metal oxide is excellent in carrier injection property and carrier transport property, low-voltage driving and low-current driving can be realized. In addition, when the surface on the anode side of the light-emitting unit is in contact with the charge generation layer 513, the charge generation layer 513 can also serve as a hole injection layer of the light-emitting unit, so the light-emitting unit does not necessarily need to be provided with a hole injection layer.

[0178] Also, when an electron injection buffer layer 119 is provided in the charge generation layer 513, since the electron injection buffer layer 119 serves as an electron injection layer in the light-emitting unit on the anode side, it is not always necessary to form an electron injection layer in the light-emitting unit on the anode side.

[0179] In FIG. 1(C), a light-emitting device having two light-emitting units has been described, but the same can be similarly applied to a light-emitting device in which three or more light-emitting units are stacked. By arranging a plurality of light-emitting units between a pair of electrodes with a charge generation layer 513 interposed therebetween as in the light-emitting device according to the present embodiment, high-brightness light emission can be enabled while keeping the current density low, and a longer-life element can be realized. Further, a light-emitting device that can be driven at a low voltage and has low power consumption can be realized.

[0180] Also, by making the emission colors of the respective light-emitting units different, light emission of a desired color can be obtained for the entire light-emitting device. For example, in a light-emitting device having two light-emitting units, a light-emitting device that emits white light as a whole can be obtained by obtaining emission colors of red and green in the first light-emitting unit and an emission color of blue in the second light-emitting unit.

[0181] Also, each layer such as the above-described organic compound layer 103, the first light-emitting unit 511, the second light-emitting unit 512, and the charge generation layer, and the electrodes can be formed by using methods such as a vapor deposition method (including a vacuum vapor deposition method), a droplet ejection method (also referred to as an inkjet method), a coating method, a gravure printing method, or the like. Further, they may contain a low molecular weight material, a medium molecular weight material (including an oligomer and a dendrimer), or a high molecular weight material.

[0182] (Embodiment 3) In the present embodiment, a display device manufactured using the light-emitting device described in Embodiment 1 and Embodiment 2 will be described with reference to FIG. 5. Note that FIG. 5(A) is a top view showing the display device, and FIG. 5(B) is a cross-sectional view obtained by cutting FIG. 5(A) along A-B and C-D. This display device includes a drive circuit portion (source line drive circuit) 601, a pixel portion 602, and a drive circuit portion (gate line drive circuit) 603 indicated by dotted lines as those for controlling the light emission of the light-emitting device. Further, 604 is a sealing substrate, and 605 is a sealing material. The inside surrounded by the sealing material 605 is a space 607.

[0183] Note that the routing wiring 608 is wiring for transmitting signals input to the source line drive circuit 601 and the gate line drive circuit 603, and receives a video signal, a clock signal, a start signal, a reset signal, etc. from an FPC (Flexible Printed Circuit) 609 which serves as an external input terminal. Although only the FPC is illustrated here, a printed wiring board (PWB) may be attached to this FPC. The display device in this specification includes not only the display device main body but also a state in which an FPC or a PWB is attached thereto.

[0184] Next, the cross-sectional structure will be described with reference to FIG. 5(B). A drive circuit section and a pixel section are formed on the element substrate 610. Here, the source line drive circuit 601 which is a drive circuit section and one pixel in the pixel section 602 are shown.

[0185] The element substrate 610 may be made of a substrate such as glass, quartz, organic resin, metal, alloy, semiconductor, etc., or a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (Polyvinyl Fluoride), polyester, acrylic resin, etc.

[0186] The structure of the transistors used for the pixels and the drive circuit is not particularly limited. For example, it may be an inverted staggered type transistor or a staggered type transistor. Also, it may be a top gate type transistor or a bottom gate type transistor. The semiconductor material used for the transistors is not particularly limited, and for example, silicon, germanium, silicon carbide, gallium nitride, etc. can be used. Alternatively, an oxide semiconductor containing at least one of indium, gallium, and zinc such as an In-Ga-Zn based metal oxide may be used.

[0187] The crystallinity of the semiconductor material used for the transistor is not particularly limited, and any of amorphous semiconductors, semiconductors having crystallinity (microcrystalline semiconductors, polycrystalline semiconductors, single-crystalline semiconductors, or semiconductors having a crystalline region in part) may be used. Using a semiconductor having crystallinity is preferable because deterioration of transistor characteristics can be suppressed.

[0188] Here, in addition to the transistors provided in the pixel and the drive circuit, for semiconductor devices such as transistors used for a touch sensor and the like described later, it is preferable to apply an oxide semiconductor. In particular, it is preferable to apply an oxide semiconductor having a wider bandgap than silicon. By using an oxide semiconductor having a wider bandgap than silicon, the current in the off state of the transistor can be reduced.

[0189] The above oxide semiconductor preferably contains at least indium (In) or zinc (Zn). Further, it is more preferable that the oxide semiconductor is an oxide semiconductor containing an oxide represented by In-M-Zn-based oxide (M is a metal such as Al, Ti, Ga, Ge, Y, Zr, Sn, La, Ce or Hf).

[0190] In particular, as the semiconductor layer, it is preferable to use an oxide semiconductor film having a plurality of crystal parts, wherein the c-axis of the crystal part is oriented perpendicular to the surface to be formed of the semiconductor layer or the upper surface of the semiconductor layer, and there is no grain boundary between adjacent crystal parts.

[0191] By using such a material as the semiconductor layer, fluctuations in electrical characteristics are suppressed, and a highly reliable transistor can be realized.

[0192] In addition, due to its low off-current, the transistor having the above-described semiconductor layer can hold the charge accumulated in the capacitor via the transistor for a long period of time. By applying such a transistor to a pixel, it is also possible to stop the drive circuit while maintaining the gradation of each pixel. As a result, an electronic device with extremely low power consumption can be realized.

[0193] For the purpose of stabilizing the characteristics of the transistor, etc., it is preferable to provide an underlying film. As the underlying film, an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film can be used, and it can be formed as a single layer or by lamination. The underlying film can be formed using a sputtering method, a CVD (Chemical Vapor Deposition) method (such as a plasma CVD method, a thermal CVD method, an MOCVD (Metal Organic CVD) method, etc.), an ALD (Atomic Layer Deposition) method, a coating method, a printing method, etc. Note that the underlying film may not be provided if it is not necessary.

[0194] Note that FET623 indicates one of the transistors formed in the drive circuit section 601. Also, the drive circuit may be formed of various CMOS circuits, PMOS circuits, or NMOS circuits. In addition, in this embodiment, a driver integrated type in which the drive circuit is formed on the substrate is shown, but this is not necessarily required, and the drive circuit can also be formed outside rather than on the substrate.

[0195] Also, the pixel section 602 is formed of a plurality of pixels including a switching FET611, a current control FET612, and a first electrode 613 electrically connected to its drain, but is not limited thereto, and a pixel section combining three or more FETs and a capacitive element may be used.

[0196] Note that an insulator 614 is formed covering the end of the first electrode 613. Here, it can be formed by using a positive photosensitive acrylic resin film.

[0197] Also, in order to make the covering property of an organic compound layer or the like formed later good, a curved surface having a curvature is formed at the upper end or the lower end of the insulator 614. For example, when a positive photosensitive acrylic resin is used as the material of the insulator 614, it is preferable to provide a curved surface having a curvature radius (0.2 μm to 3 μm) only at the upper end of the insulator 614. Also, either a negative photosensitive resin or a positive photosensitive resin can be used as the insulator 614.

[0198] On the first electrode 613, an organic compound layer 616 and a second electrode 617 are respectively formed. Here, as the material used for the first electrode 613 that functions as an anode, it is desirable to use a material with a large work function. For example, in addition to single-layer films such as ITO films, indium tin oxide films containing silicon, indium oxide films containing 2 to 20 wt% of zinc oxide, titanium nitride films, chromium films, tungsten films, Zn films, Pt films, etc., a laminate of a titanium nitride film and a film mainly composed of aluminum, a three-layer structure of a titanium nitride film, a film mainly composed of aluminum, and a titanium nitride film can be used. Note that when a laminated structure is used, the resistance as wiring is low, good ohmic contact can be achieved, and it can further function as an anode.

[0199] Also, the organic compound layer 616 is formed by various methods such as vapor deposition using a vapor deposition mask, inkjet method, spin coating method, etc. The organic compound layer 616 includes the configurations as described in Embodiment 1 and Embodiment 2. Also, as other materials constituting the organic compound layer 616, low molecular compounds or high molecular compounds (including oligomers and dendrimers) may be used.

[0200] Furthermore, as the material used for the second electrode 617 formed on the organic compound layer 616 and functioning as a cathode, it is preferable to use a material with a small work function (Al, Mg, Li, Ca, or alloys and compounds thereof (MgAg, MgIn, AlLi, etc.)). Note that when the light generated in the organic compound layer 616 is transmitted through the second electrode 617, it is good to use a laminate of a thin metal film with a reduced film thickness and a transparent conductive film (ITO, indium oxide containing 2 to 20 wt% of zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) as the second electrode 617.

[0201] Note that a light-emitting device is formed by the first electrode 613, the organic compound layer 616, and the second electrode 617. The light-emitting device is the light-emitting device described in Embodiment 1 and Embodiment 2. Note that a plurality of light-emitting devices are formed in the pixel portion. In the display device of the present embodiment, both the light-emitting device described in Embodiment 1 and Embodiment 2 and the light-emitting device having other configurations may be mixed.

[0202] Further, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, a structure is provided in which the light-emitting device 618 is provided in the space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. Note that the space 607 is filled with a filler, and in addition to the case where an inert gas (nitrogen, argon, etc.) is filled, it may be filled with a sealing material. It is a preferable configuration to form a recess in the sealing substrate and provide a drying material therein to suppress deterioration due to the influence of moisture.

[0203] Note that it is preferable to use an epoxy resin and glass frit for the sealing material 605. Further, it is desirable that these materials are materials that do not permeate moisture and oxygen as much as possible. In addition to a glass substrate and a quartz substrate, a plastic substrate made of FRP (Fiber Reinforced Plastics), PVF (polyvinyl fluoride), polyester, acrylic resin, or the like can be used as the material for the sealing substrate 604.

[0204] Although not shown in FIG. 5, a protective film may be provided on the second electrode. The protective film may be formed of an organic resin film or an inorganic insulating film. Further, the protective film may be formed so as to cover the exposed portion of the sealing material 605. Further, the protective film can be provided so as to cover the exposed side surfaces of the surfaces and side surfaces of the pair of substrates, the sealing layer, the insulating layer, and the like.

[0205] A material that hardly permeates impurities such as water can be used for the protective film. Therefore, it is possible to effectively suppress the diffusion of impurities such as water from the outside to the inside.

[0206] As materials for forming the protective film, oxides, nitrides, fluorides, sulfides, ternary compounds, metals, polymers, etc. can be used. For example, materials containing aluminum oxide, hafnium oxide, hafnium silicate, lanthanum oxide, silicon oxide, strontium titanate, tantalum oxide, titanium oxide, zinc oxide, niobium oxide, zirconium oxide, tin oxide, yttrium oxide, cerium oxide, scandium oxide, erbium oxide, vanadium oxide or indium oxide, etc., materials containing aluminum nitride, hafnium nitride, silicon nitride, tantalum nitride, titanium nitride, niobium nitride, molybdenum nitride, zirconium nitride or gallium nitride, etc., materials containing nitrides containing titanium and aluminum, oxides containing titanium and aluminum, oxides containing aluminum and zinc, sulfides containing manganese and zinc, sulfides containing cerium and strontium, oxides containing erbium and aluminum, oxides containing yttrium and zirconium, etc. can be used.

[0207] The protective film is preferably formed using a film-forming method with good step coverage. One such technique is the atomic layer deposition (ALD) method. It is preferable to use a material that can be formed using the ALD method for the protective film. By using the ALD method, a protective film that is dense, has reduced defects such as cracks and pinholes, or has a uniform thickness can be formed. Also, the damage to the processing member when forming the protective film can be reduced.

[0208] For example, by forming a protective film using the ALD method, a protective film that is uniform and has few defects can be formed on the surface with a complex uneven shape, the upper surface, side surfaces and back surface of the touch panel.

[0209] In the above manner, a display device manufactured using the light-emitting devices described in Embodiment 1 and Embodiment 2 can be obtained.

[0210] Since the display device in this embodiment uses the light-emitting devices described in Embodiment 1 and Embodiment 2, a display device with good characteristics can be obtained. Specifically, since the light-emitting devices described in Embodiment 1 and Embodiment 2 have high luminous efficiency, it is possible to obtain a display device with low power consumption. In addition, since the light-emitting devices described in Embodiment 1 and Embodiment 2 have good reliability, a display device with good reliability can be obtained. Moreover, in addition to that, since the light-emitting devices described in Embodiment 1 and Embodiment 2 can be made into light-emitting devices with good chromaticity and color purity, a display device with good display quality can be obtained.

[0211] In addition, this embodiment can be freely combined with other embodiments.

[0212] (Embodiment 4) As illustrated in FIGS. 6(A) and 6(B), a plurality of light-emitting devices 130 are formed on the insulating layer 175 to form a display device. In this embodiment, a display device according to another aspect of the present invention will be described in detail.

[0213] The display device 100 has a pixel portion 177 in which a plurality of pixels 178 are arranged in a matrix. The pixel 178 has a sub-pixel 110R, a sub-pixel 110G, and a sub-pixel 110B.

[0214] In this specification and the like, for example, when explaining matters common to the sub-pixel 110R, the sub-pixel 110G, and the sub-pixel 110B, they may be described by referring to them as the sub-pixel 110. For other components distinguished by alphabets, when explaining matters common to them, symbols with the alphabets omitted may be used for the description.

[0215] The sub-pixel 110R exhibits red light, the sub-pixel 110G exhibits green light, and the sub-pixel 110B exhibits blue light. Thereby, an image can be displayed on the pixel portion 177. In the present embodiment, three-color sub-pixels of red (R), green (G), and blue (B) are taken as examples for description, but combinations of sub-pixels of other colors may also be used. Further, the number of sub-pixels is not limited to three, and may be four or more. Examples of the four sub-pixels include four-color sub-pixels of R, G, B, and white (W), four-color sub-pixels of R, G, B, and Y, and four sub-pixels of R, G, B, and infrared light (IR), and the like.

[0216] In this specification and the like, the row direction may be referred to as the X direction, and the column direction may be referred to as the Y direction. The X direction and the Y direction intersect, for example, perpendicularly.

[0217] FIG. 6(A) shows an example in which sub-pixels of different colors are arranged side by side in the X direction, and sub-pixels of the same color are arranged side by side in the Y direction. Note that sub-pixels of different colors may be arranged side by side in the Y direction, and sub-pixels of the same color may be arranged side by side in the X direction.

[0218] An interconnecting portion 140 is provided outside the pixel portion 177, and a region 141 may be provided. When the region 141 is provided, the region 141 is provided between the pixel portion 177 and the interconnecting portion 140. When the region 141 is provided, an organic compound layer 103 is provided in the region 141. Further, a conductive layer 151C is provided in the interconnecting portion 140.

[0219] FIG. 6(A) shows an example in which the region 141 and the interconnecting portion 140 are located on the right side of the pixel portion 177, but the positions of the region 141 and the interconnecting portion 140 are not particularly limited. Further, the region 141 and the interconnecting portion 140 may be singular or plural.

[0220] FIG. 6(B) is an example of a cross-sectional view between the dashed-dotted line A1 - A2 in FIG. 6(A). As shown in FIG. 6(B), the display device 100 includes an insulating layer 171, a conductive layer 172 on the insulating layer 171, an insulating layer 173 on the insulating layer 171 and 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). Openings reaching the conductive layer 172 are provided in the insulating layer 175, the insulating layer 174, and the insulating layer 173, and plugs 176 are provided so as to fill the openings.

[0221] In the pixel portion 177, a light-emitting device 130 is provided on the insulating layer 175 and the plug 176. Also, a protective layer 131 is provided so as to cover the light-emitting device 130. The substrate 120 is bonded by a resin layer 122 on the protective layer 131. Further, it is preferable that an inorganic insulating layer 125 and an insulating layer 127 on the inorganic insulating layer 125 are provided between adjacent light-emitting devices 130.

[0222] In FIG. 6(B), a plurality of 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 each connected into one.

[0223] In FIG. 6(B), light-emitting devices 130R, 130G, and 130B are shown as the light-emitting device 130. The light-emitting devices 130R, 130G, and 130B are assumed to emit light of different colors. For example, the light-emitting device 130R can emit red light, the light-emitting device 130G can emit green light, and the light-emitting device 130B can emit blue light. Also, the light-emitting device 130R, the light-emitting device 130G, or the light-emitting device 130B may emit other visible light or infrared light.

[0224] The display device according to one aspect of the present invention can be a top emission type that emits light in a direction opposite to the substrate on which the light emitting device is formed. Note that the display device according to one aspect of the present invention may be a bottom emission type.

[0225] The light emitting device 130R includes a first electrode 101R (pixel electrode) composed 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. Note that the common layer 104 may or may not be provided, but it is preferably provided because it can reduce damage to the organic compound layer 103R during processing.

[0226] The light emitting device 130G includes a first electrode 101G (pixel electrode) composed 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. Note that the common layer 104 may or may not be provided, but it is preferably provided because it can reduce damage to the organic compound layer 103G during processing.

[0227] The light emitting device 130B has a configuration as shown in Embodiment 1 and Embodiment 2. The light emitting device 130B includes a first electrode 101B (pixel electrode) composed of a conductive layer 151B and a conductive layer 152B, 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. Note that the common layer 104 may or may not be provided, but it is preferably provided because it can reduce damage to the organic compound layer 103B during processing. Further, when 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 1 and Embodiment 2.

[0228] Note that the common layer 104 is preferably an electron injection layer or an electron transport layer, and more preferably an electron injection layer. Further, when it is an electron transport layer, the electron transport layer preferably has a stacked structure, and among the stacked layers, the layer on the second electrode side is more preferably the common layer 104, and the layer on the light-emitting layer side is more preferably the organic compound layer 103.

[0229] In addition, since the light-emitting device 130R and the light-emitting device 130G are also light-emitting devices manufactured through a photolithography process, it is possible to obtain a light-emitting device with a low driving voltage in which an increase in the driving voltage due to the photolithography process is suppressed.

[0230] Of the pixel electrode and the common electrode included in the light-emitting device 130, one functions as an anode and the other functions as a cathode. Hereinafter, unless otherwise specified, it will be described assuming that the pixel electrode functions as an anode and the common electrode functions as a cathode.

[0231] The organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are independent in an island shape for each light-emitting device or for each emission color. By providing the organic compound layer 103 in an island shape for each light-emitting device 130, it is possible to suppress the leakage current between adjacent light-emitting devices 130 even in a high-definition display device. Thereby, crosstalk can be prevented, and a display device with extremely high contrast can be realized. In particular, a display device with high current efficiency at low luminance can be realized.

[0232] The island-shaped organic compound layer 103 is formed by forming an organic compound film and processing the organic compound film using a photolithography method.

[0233] The organic compound layer 103 is preferably provided so as to cover the upper surface and the side surface of the first electrode (pixel electrode) of the light-emitting device 130. Thereby, it becomes easier to increase the aperture ratio of the display device 100 as compared with a configuration in which the end portion of the organic compound layer 103 is located inside the end portion of the pixel electrode. Further, by covering the side surface of the pixel electrode of the light-emitting device 130 with the organic compound layer 103, it is possible to suppress the contact between the pixel electrode and the second electrode 102, and thus it is possible to suppress a short circuit of the light-emitting device 130.

[0234] Further, in the display device according to one aspect of the present invention, it is preferable that the first electrode (pixel electrode) of the light-emitting device has a stacked structure. For example, in the example shown in FIG. 6(B), the first electrode of the light-emitting device 130 has a stacked structure of a conductive layer 151 and a conductive layer 152.

[0235] As the conductive layer 151, for example, a metal material can be used. Specifically, for example, metals such as aluminum (Al), titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), gallium (Ga), zinc (Zn), indium (In), tin (Sn), molybdenum (Mo), tantalum (Ta), tungsten (W), palladium (Pd), gold (Au), platinum (Pt), silver (Ag), yttrium (Y), neodymium (Nd), etc., and alloys containing these appropriately combined can also be used.

[0236] As the conductive layer 152, an oxide having any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used. For example, 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, etc. It is preferable to use a conductive oxide containing any one or more of them. In particular, indium tin oxide containing silicon has a large work function, for example, a work function of 4.0 eV or more, and thus can be suitably used as the conductive layer 152.

[0237] The conductive layer 151 may have a laminated structure of a plurality of layers having different materials, and the conductive layer 152 may also have a laminated structure of a plurality of layers having different materials. In this case, the conductive layer 151 may have a layer using a material that can be used for the conductive layer 152 such as a conductive oxide, and the conductive layer 152 may also have a layer using a material that can be used for the conductive layer 151 such as a metal material. For example, when the conductive layer 151 has a laminated structure of two or more layers, the layer in contact with the conductive layer 152 can be a layer using a material that can be used for the conductive layer 152.

[0238] Note that the side surface of the conductive layer 151 preferably has a tapered shape. Specifically, the side surface of the conductive layer 151 preferably has a tapered shape with a taper angle of less than 90°. In this case, the conductive layer 152 provided along the side surface of the conductive layer 151 also has a tapered shape. By making the side surface of the conductive layer 152 have a tapered shape, the covering property of the organic compound layer 103 provided along the side surface of the conductive layer 152 can be enhanced.

[0239] Subsequently, an example of a method for manufacturing the display device 100 having the configuration shown in FIG. 6(A) will be described with reference to FIGS. 7 to 12.

[0240] [Example of manufacturing method] The thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed using a sputtering method, a chemical vapor deposition (CVD) method, a vacuum evaporation method, a pulsed laser deposition (PLD) method, or an ALD method.

[0241] Also, the thin films (insulating films, semiconductor films, conductive films, etc.) constituting the display device can be formed by a wet film formation method such as spin coating, dipping, spray coating, inkjet, dispensing, screen printing, offset printing, doctor knife method, slit coating, roll coating, curtain coating, or knife coating.

[0242] When processing the thin film that constitutes the display device, for example, it can be processed using photolithography.

[0243] In the photolithography method, as the light used for exposure, for example, i-line (wavelength 365 nm), g-line (wavelength 436 nm), h-line (wavelength 405 nm), or light obtained by mixing these can be used. In addition, ultraviolet light, KrF laser light, ArF laser light, etc. can also be used. Further, exposure may be performed by immersion lithography technology. Also, as the light used for exposure, extreme ultraviolet (EUV) light, or X-rays may be used. Instead of the light used for exposure, an electron beam can also be used.

[0244] For the etching of the thin film, a dry etching method, a wet etching method, a sandblasting method, etc. can be used.

[0245] First, as shown in FIG. 7(A), an insulating layer 171 is formed on a substrate (not shown). Subsequently, a conductive layer 172 and a conductive layer 179 are formed on the insulating layer 171, and an insulating layer 173 is formed on the insulating layer 171 so as to cover the conductive layer 172 and the conductive layer 179. Subsequently, an insulating layer 174 is formed on the insulating layer 173, and an insulating layer 175 is formed on the insulating layer 174.

[0246] As the substrate, a substrate having heat resistance sufficient to withstand at least subsequent heat treatment can be used. For example, a glass substrate, a quartz substrate, a sapphire substrate, a ceramic substrate, or an organic resin substrate, a single crystal semiconductor substrate made of silicon or silicon carbide, a polycrystalline semiconductor substrate, a compound semiconductor substrate such as silicon germanium, a semiconductor substrate such as an SOI substrate can be used.

[0247] Subsequently, as shown in FIG. 7(A), an opening reaching the conductive layer 172 is formed in the insulating layer 175, the insulating layer 174, and the insulating layer 173. Subsequently, a plug 176 is formed so as to fill the opening.

[0248] Subsequently, as shown in FIG. 7(A), on the plug 176 and on the insulating layer 175, a conductive film 151f which will later become the conductive layer 151R, the conductive layer 151G, the conductive layer 151B, and the conductive layer 151C, and a conductive film 152f which will later become the conductive layer 152R, the conductive layer 152G, the conductive layer 152B, and the conductive layer 152C are formed. As the conductive film 151f, for example, a metal material can be used. As the conductive film 152f, for example, an oxide having any one or more selected from indium, tin, zinc, gallium, titanium, aluminum, and silicon can be used.

[0249] Subsequently, as shown in FIG. 7(A), a resist mask 191 is formed on the conductive film 152f. The resist mask 191 can be formed by applying a photosensitive material (photoresist) and performing exposure and development.

[0250] Subsequently, as shown in FIG. 7(B), for example, the conductive film 151f and the conductive film 152f in a region that does not overlap with the resist mask 191 are removed. Thereby, the conductive layer 151 and the conductive layer 152 are formed.

[0251] Subsequently, as shown in FIG. 7(C), the resist mask 191 is removed. The resist mask 191 can be removed, for example, by ashing using oxygen plasma.

[0252] Subsequently, as shown in FIG. 7(D), on the conductive layer 152R, on the conductive layer 152G, on the conductive layer 152B, on the conductive layer 152C, and on the insulating layer 175, an insulating film 156f which will later become the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, and the insulating layer 156C is formed.

[0253] For the insulating film 156f, an inorganic insulating film such as an oxide insulating film, a nitride insulating film, an oxynitride insulating film, or a nitroxide insulating film, for example, silicon oxynitride can be used.

[0254] Subsequently, as shown in FIG. 7(E), by processing the insulating film 156f, the insulating layer 156R, the insulating layer 156G, the insulating layer 156B, and the insulating layer 156C are formed.

[0255] Subsequently, as shown in FIG. 8(A), an organic compound film 103Rf is formed on the conductive layer 152R, on the conductive layer 152G, on the conductive layer 152B, and on the insulating layer 175. As shown in FIG. 8(A), the organic compound film 103Rf is not formed on the conductive layer 152C.

[0256] Subsequently, as shown in FIG. 8(A), a sacrificial film 158Rf and a mask film 159Rf are formed.

[0257] By providing the sacrificial film 158Rf on the organic compound film 103Rf, damage to the organic compound film 103Rf during the manufacturing process of the display device can be reduced, and the reliability of the light-emitting device can be enhanced.

[0258] For the sacrificial film 158Rf, a film with high resistance to the processing conditions of the organic compound film 103Rf is used, specifically, a film with a large etching selectivity ratio with respect to the organic compound film 103Rf. For the mask film 159Rf, a film with a large etching selectivity ratio with respect to the sacrificial film 158Rf is used.

[0259] Also, the sacrificial film 158Rf and the mask film 159Rf are formed at a temperature lower than the heat-resistant temperature of the organic compound film 103Rf. As the substrate temperature when forming the sacrificial film 158Rf and the mask film 159Rf, typically, it is 100°C or higher and 200°C or lower, preferably 100°C or higher and 150°C or lower, more preferably 100°C or higher and 120°C or lower, respectively.

[0260] It is preferable to use a film that can be removed by a wet etching method or a dry etching method for the sacrificial film 158Rf and the mask film 159Rf.

[0261] Note that the sacrificial film 158Rf formed in contact with the organic compound film 103Rf is preferably formed using a formation method that causes less damage to the organic compound film 103Rf than the mask film 159Rf. For example, the ALD method (Atomic Layer Deposition method) or the vacuum evaporation method is more preferable than the sputtering method.

[0262] As the sacrificial film 158Rf and the mask film 159Rf, for example, one or more of a metal film, an alloy film, a metal oxide film, a semiconductor film, an organic insulating film, and an inorganic insulating film can be used respectively.

[0263] For the sacrificial film 158Rf and the mask film 159Rf, for example, metal materials such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, titanium, aluminum, yttrium, zirconium, and tantalum, or alloy materials containing the metal materials can be used respectively. In particular, it is preferable to use a low melting point material such as aluminum or silver. By using a metal material capable of shielding ultraviolet rays for one or both of the sacrificial film 158Rf and the mask film 159Rf, it is possible to suppress the irradiation of ultraviolet rays during pattern exposure to the organic compound film 103Rf, and since the deterioration of the organic compound film 103Rf can be suppressed, it is preferable.

[0264] In addition, for the sacrificial film 158Rf and the mask film 159Rf, metal oxides such as In-Ga-Zn oxide, indium oxide, In-Zn oxide, In-Sn oxide, indium titanate (In-Ti oxide), indium tin zinc oxide (In-Sn-Zn oxide), indium titanium zinc oxide (In-Ti-Zn oxide), indium gallium tin zinc oxide (In-Ga-Sn-Zn oxide), and indium tin oxide containing silicon can be used respectively.

[0265] In addition, in the above metal oxide, element M (M is one or more selected from aluminum, silicon, boron, yttrium, copper, vanadium, beryllium, titanium, iron, nickel, germanium, zirconium, molybdenum, lanthanum, cerium, neodymium, hafnium, tantalum, tungsten, or magnesium) may be used instead of gallium.

[0266] As the sacrificial film 158Rf and the mask film 159Rf, for example, it is preferable to use a semiconductor material such as silicon or germanium because it has a high affinity with the semiconductor manufacturing process. Alternatively, a compound containing the semiconductor material can be used.

[0267] Also, as the sacrificial film 158Rf and the mask film 159Rf, various inorganic insulating films can be used respectively. In particular, the oxide insulating film is preferable because it has a higher adhesion to the organic compound film 103Rf than the nitride insulating film.

[0268] Subsequently, as shown in FIG. 8(A), a resist mask 190R is formed. The resist mask 190R can be formed by applying a photosensitive material (photoresist) and performing exposure and development.

[0269] The resist mask 190R is provided at a position overlapping the conductive layer 152R. The resist mask 190R is preferably also provided at a position overlapping the conductive layer 152C. Thereby, it is possible to suppress the conductive layer 152C from being damaged during the manufacturing process of the display device.

[0270] Subsequently, as shown in FIG. 8(B), using the resist mask 190R, a part of the mask film 159Rf is removed to form a mask layer 159R. The mask layer 159R remains on the conductive layer 152R and on the conductive layer 152C. Then, the resist mask 190R is removed. Subsequently, using the mask layer 159R as a mask (also referred to as a hard mask), a part of the sacrificial film 158Rf is removed to form a sacrificial layer 158R.

[0271] By using the wet etching method, compared with the case of using the dry etching method, the damage applied to the organic compound film 103Rf during the processing of the sacrificial film 158Rf and the mask film 159Rf can be reduced. When using the wet etching method, for example, it is preferable to use a developer, an alkaline aqueous solution such as a tetramethylammonium hydroxide (TMAH) aqueous solution, a dilute hydrofluoric acid, oxalic acid, phosphoric acid, acetic acid, nitric acid, or an acid aqueous solution such as a chemical solution using a mixed liquid thereof.

[0272] Also, when using a dry etching method in processing the sacrificial film 158Rf, deterioration of the organic compound film 103Rf can be suppressed by not using a gas containing oxygen as the etching gas.

[0273] The resist mask 190R can be removed in the same manner as the resist mask 191.

[0274] Subsequently, as shown in FIG. 8(B), the organic compound film 103Rf is processed to form the organic compound layer 103R. For example, using the mask layer 159R and the sacrificial layer 158R as a hard mask, a part of the organic compound film 103Rf is removed to form the organic compound layer 103R.

[0275] As a result, as shown in FIG. 8(B), a laminated structure of the organic compound layer 103R, the sacrificial layer 158R, and the mask layer 159R remains on the conductive layer 152R. Also, the conductive layer 152G and the conductive layer 152B are exposed.

[0276] Processing of the organic compound film 103Rf is preferably performed by anisotropic etching. In particular, anisotropic dry etching is preferred. Alternatively, wet etching may be used.

[0277] When using a dry etching method, deterioration of the organic compound film 103Rf can be suppressed by not using a gas containing oxygen as the etching gas.

[0278] Also, a gas containing oxygen may be used as the etching gas. By the etching gas containing oxygen, the etching rate can be increased. Therefore, etching can be performed under low-power conditions while maintaining the etching rate at a sufficient speed. For this reason, damage to the organic compound film 103Rf can be suppressed. Furthermore, problems such as adhesion of reaction products generated during etching can be suppressed.

[0279] When using a dry etching method, for example, H 2 , CF 4 , C 4 F8 、SF 6 、CHF 3 、Cl 2 、H 2 O, BCl 3 、Preferably, a gas containing one or more of the 18th group elements such as He, Ar, etc. is used as the etching gas. Or, preferably, a gas containing one or more of these and a gas containing oxygen is used as the etching gas. Or, oxygen gas may be used as the etching gas.

[0280] Subsequently, as shown in FIG. 9(A), an organic compound film 103Gf that will later become the organic compound layer 103G is formed.

[0281] The organic compound film 103Gf can be formed by the same method as the method used for forming the organic compound film 103Rf. Also, the organic compound film 103Gf can have the same configuration as the organic compound film 103Rf.

[0282] Subsequently, as shown in FIG. 9(A), a sacrificial film 158Gf and a mask film 159Gf are formed in sequence. Then, a resist mask 190G is formed. The materials and formation methods of the sacrificial film 158Gf and the mask film 159Gf are the same as the conditions applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the resist mask 190G are the same as the conditions applicable to the resist mask 190R.

[0283] The resist mask 190G is provided at a position overlapping the conductive layer 152G.

[0284] Subsequently, as shown in FIG. 9(B), using the resist mask 190G, a part of the mask film 159Gf is removed to form a mask layer 159G. The mask layer 159G remains on the conductive layer 152G. Then, the resist mask 190G is removed. Subsequently, using the mask layer 159G as a mask, a part of the sacrificial film 158Gf is removed to form a sacrificial layer 158G. Subsequently, the organic compound film 103Gf is processed to form the organic compound layer 103G.

[0285] Subsequently, as shown in FIG. 9(C), an organic compound film 103Bf is formed.

[0286] The organic compound film 103Bf can be formed by the same method as that used for forming the organic compound film 103Rf. Also, the organic compound film 103Bf can have the same configuration as the organic compound film 103Rf.

[0287] Subsequently, as shown in FIG. 9(C), a sacrificial film 158Bf and a mask film 159Bf are formed in sequence. Thereafter, a resist mask 190B is formed. The materials and formation methods of the sacrificial film 158Bf and the mask film 159Bf are the same as the conditions applicable to the sacrificial film 158Rf and the mask film 159Rf. The materials and formation methods of the resist mask 190B are the same as the conditions applicable to the resist mask 190R.

[0288] The resist mask 190B is provided at a position overlapping the conductive layer 152B.

[0289] Subsequently, as shown in FIG. 9(D), using the resist mask 190B, a part of the mask film 159Bf is removed to form a mask layer 159B. The mask layer 159B remains on the conductive layer 152B. Thereafter, the resist mask 190B is removed. Subsequently, using the mask layer 159B as a mask, a part of the sacrificial film 158Bf is removed to form a sacrificial layer 158B. Subsequently, the organic compound film 103Bf is processed to form an organic compound layer 103B. For example, using the mask layer 159B and the sacrificial layer 158B as hard masks, a part of the organic compound film 103Bf is removed to form the organic compound layer 103B.

[0290] As a result, as shown in FIG. 9(D), a stacked structure of the organic compound layer 103B, the sacrificial layer 158B, and the mask layer 159B remains on the conductive layer 152B. Also, the mask layer 159R and the mask layer 159G are exposed.

[0291] In addition, the side surfaces of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B are preferably perpendicular or substantially perpendicular to the surface to be formed. For example, it is preferable that the angle formed by the surface to be formed and these side surfaces is 60 degrees or more and 90 degrees or less.

[0292] As described above, the distance between two adjacent ones of the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B formed by using the photolithography method can be narrowed to 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less, or 1 μm or less. Here, the said distance can be defined, for example, as the distance between two opposing end portions of two adjacent ones among the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B. By narrowing the distance between the island-shaped organic compound layers in this way, a display device having high definition and a large aperture ratio can be provided. Also, the distance between the first electrodes between adjacent light-emitting devices can also be narrowed, and can be, for example, 10 μm or less, 8 μm or less, 5 μm or less, 3 μm or less, 2 μm or less. Note that the distance between the first electrodes between adjacent light-emitting devices is preferably 2 μm or more and 5 μm or less.

[0293] Subsequently, as shown in FIG. 10(A), it is preferable to remove the mask layer 159R, the mask layer 159G, and the mask layer 159B.

[0294] For the step of removing the mask layer, the same method as the processing step of the mask film can be used. In particular, by using the wet etching method, the damage applied to the organic compound layer 103 when removing the mask layer can be reduced as compared with the case of using the dry etching method.

[0295] Alternatively, the mask layer may be removed by dissolving it in a polar solvent such as water or alcohol. Examples of the alcohol include ethyl alcohol, methyl alcohol, isopropyl alcohol (IPA), or glycerin.

[0296] After removing the mask layer, a drying process may be performed to remove the water adsorbed on the surface. For example, heat treatment can be performed in an inert gas atmosphere or a reduced pressure atmosphere. The heat treatment can be performed at a temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, more preferably 70°C or higher and 120°C or lower, as the substrate temperature. It is preferable to use a reduced pressure atmosphere because drying can be performed at a lower temperature.

[0297] Subsequently, as shown in FIG. 10(B), an inorganic insulating film 125f is formed.

[0298] Subsequently, as shown in FIG. 10(C), an insulating film 127f that will later become the insulating layer 127 is formed on the inorganic insulating film 125f.

[0299] When forming the inorganic insulating film 125f and the insulating film 127f, the substrate temperature is preferably 60°C or higher, 80°C or higher, 100°C or higher, or 120°C or higher, and 200°C or lower, 180°C or lower, 160°C or lower, 150°C or lower, or 140°C or lower, respectively.

[0300] As the inorganic insulating film 125f, it is preferable to form an insulating film with a thickness of 3 nm or more, 5 nm or more, or 10 nm or more, and 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less.

[0301] The inorganic insulating film 125f is preferably formed using, for example, the ALD method. Using the ALD method is preferable because film formation damage can be reduced and a film with high coverage can be formed. As the inorganic insulating film 125f, it is preferable to form an aluminum oxide film using, for example, the ALD method.

[0302] The insulating film 127f is preferably formed using the aforementioned wet film formation method. The insulating film 127f is preferably formed by spin coating using a photosensitive material, and more specifically, it is preferably formed using a photosensitive resin composition containing an acrylic resin.

[0303] Subsequently, exposure is performed to make a part of the insulating film 127f sensitive to visible light or ultraviolet light. The insulating layer 127 is formed in a region sandwiched between any two of the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B, and around the conductive layer 152C.

[0304] The width of the insulating layer 127 to be formed later can be controlled by the exposure region on the insulating film 127f. In the present embodiment, processing is performed so that the insulating layer 127 has a portion overlapping the upper surface of the conductive layer 151.

[0305] The light used for exposure preferably includes i-line (wavelength 365 nm). Further, the light used for exposure may include at least one of g-line (wavelength 436 nm) and h-line (wavelength 405 nm).

[0306] Subsequently, as shown in FIG. 11(A), development is performed to remove the exposed region of the insulating film 127f and form the insulating layer 127a.

[0307] Subsequently, as shown in FIG. 11(B), an etching process is performed using the insulating layer 127a as a mask to remove a part of the inorganic insulating film 125f and reduce the film thickness of a part of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B. Thereby, an inorganic insulating layer 125 is formed under the insulating layer 127a. Further, the surfaces of the portions where the film thicknesses of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B are thin are exposed. Hereinafter, the etching process using the insulating layer 127a as a mask may be referred to as the first etching process.

[0308] The first etching process can be performed by dry etching or wet etching. When the inorganic insulating film 125f is formed using the same materials as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, it is preferable because the first etching process can be performed in a batch.

[0309] When performing dry etching, it is preferable to use a chlorine-based gas. As the chlorine-based gas, Cl 2 、BCl3 , SiCl 4 , and CCl 4 etc. can be used alone or in combination of two or more gases. Further, oxygen gas, hydrogen gas, helium gas, argon gas, etc. can be appropriately added to the above chlorine-based gas, either alone or in combination of two or more gases. By using dry etching, regions with a thin film thickness of the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B can be formed with good in-plane uniformity.

[0310] As the dry etching apparatus, a dry etching apparatus having a high-density plasma source can be used. As the dry etching apparatus having a high-density plasma source, for example, an inductively coupled plasma (ICP) etching apparatus can be used. Alternatively, a capacitively coupled plasma (CCP) etching apparatus having parallel plate electrodes can be used.

[0311] Further, it is preferable to perform the first etching process by wet etching. By using the wet etching method, the damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced as compared with the case of using the dry etching method. For example, wet etching can be performed using an alkaline solution. For example, for wet etching of an aluminum oxide film, an aqueous solution of TMAH, which is an alkaline solution, can be used. Also, an acid solution containing fluoride can be used. In this case, wet etching can be performed by the paddle method. When the inorganic insulating film 125f is formed using the same material as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, the above etching process can be performed in a batch, which is preferable.

[0312] In the first etching process, the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B are not completely removed, and the etching process is stopped with the film thickness reduced. In this way, by leaving the corresponding sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B on the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B, it is possible to prevent the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B from being damaged in the subsequent process.

[0313] Subsequently, it is preferable to expose the entire substrate and irradiate the insulating layer 127a with visible light or ultraviolet light. The energy density of the exposure is greater than 0 mJ / cm 2 and preferably less than or equal to 800 mJ / cm 2 ; more preferably, it is greater than 0 mJ / cm 2 and less than or equal to 500 mJ / cm 2 Performing such exposure after development may improve the transparency of the insulating layer 127a. Also, in a subsequent process, it may be possible to reduce the substrate temperature required for the heat treatment to deform the insulating layer 127a into a tapered shape.

[0314] Here, as the sacrificial layer 158R, the sacrificial layer 158G, and the sacrificial layer 158B, the presence of a barrier insulating layer against oxygen (for example, an aluminum oxide film, etc.) can reduce the diffusion of oxygen into the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B.

[0315] Subsequently, a heat treatment (also referred to as post-bake) is performed. By performing the heat treatment, the insulating layer 127a can be deformed into an insulating layer 127 having a tapered shape on the side surface (FIG. 11(C)). The heat treatment is performed at a temperature lower than the heat resistance temperature of the organic compound layer. The heat treatment can be performed at a substrate temperature of 50°C or higher and 200°C or lower, preferably 60°C or higher and 150°C or lower, more preferably 70°C or higher and 130°C or lower. The heating atmosphere may be an air atmosphere or an inert gas atmosphere. Also, the heating atmosphere may be an atmospheric pressure atmosphere or a reduced pressure atmosphere. Thereby, the adhesion between the insulating layer 127 and the inorganic insulating layer 125 can be improved, and the corrosion resistance of the insulating layer 127 can also be improved.

[0316] In the first etching process, by not completely removing the sacrificial layers 158R, 158G, and 158B but leaving the sacrificial layers 158R, 158G, and 158B in a state where the film thickness is reduced, it is possible to prevent the organic compound layers 103R, 103G, and 103B from being damaged and deteriorated in the heat treatment. Therefore, the reliability of the light-emitting device can be enhanced.

[0317] Subsequently, as shown in FIG. 12(A), using the insulating layer 127 as a mask, an etching process is performed to remove a part of the sacrificial layers 158R, 158G, and 158B. Thereby, openings are formed in each of the sacrificial layers 158R, 158G, and 158B, and the upper surfaces of the organic compound layers 103R, 103G, 103B, and the conductive layer 152C are exposed. Hereinafter, this etching process may be referred to as the second etching process.

[0318] The end portion of the inorganic insulating layer 125 is covered with the insulating layer 127. Also, in FIG. 12(A), an example is shown in which a part of the end portion of the sacrificial layer 158 (specifically, the tapered portion formed by the first etching process) is covered with the insulating layer 127, and the tapered portion formed by the second etching process is exposed.

[0319] The second etching process is performed by wet etching. By using the wet etching method, the damage to the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B can be reduced as compared with the case of using the dry etching method. Wet etching can be performed using, for example, an alkaline solution or an acidic solution. It is preferably an aqueous solution so that the organic compound layer 103 does not dissolve.

[0320] Subsequently, as shown in FIG. 12(B), a cathode 102 is formed on the organic compound layer 103R, on the organic compound layer 103G, on the organic compound layer 103B, on the conductive layer 152C, and on the insulating layer 127. The cathode 102 can be formed by a method such as a sputtering method or a vacuum evaporation method.

[0321] Subsequently, as shown in FIG. 12(C), a protective layer 131 is formed on the cathode 102. The protective layer 131 can be formed by a method such as a vacuum evaporation method, a sputtering method, a CVD method, or an ALD method.

[0322] Subsequently, the display device can be manufactured by bonding the substrate 120 onto the protective layer 131 using the resin layer 122. As described above, in the method for manufacturing a display device according to one aspect of the present invention, the insulating layer 156 is provided so as to have a region overlapping with the side surface of the conductive layer 151, and the conductive layer 152 is formed so as to cover the conductive layer 151 and the insulating layer 156. Thereby, the yield of the display device can be increased and the occurrence of defects can be suppressed.

[0323] As described above, in the method for manufacturing a display device according to one aspect of the present invention, the island-shaped organic compound layer 103R, the island-shaped organic compound layer 103G, and the island-shaped organic compound layer 103B are not formed using a fine metal mask, but are formed by processing after forming a film on one surface. Therefore, the island-shaped layers can be formed with a uniform thickness. And a high-definition display device or a display device with a high aperture ratio can be realized. Also, even if the fineness or aperture ratio is high and the distance between sub-pixels is extremely short, it is possible to suppress the organic compound layer 103R, the organic compound layer 103G, and the organic compound layer 103B from contacting each other in adjacent sub-pixels. Therefore, it is possible to suppress the generation of leakage current between sub-pixels. Thereby, crosstalk can be prevented, and a display device with extremely high contrast can be realized. Also, even in a display device having a tandem type light-emitting device manufactured using a photolithography method, a display device with good characteristics can be provided.

[0324] (Embodiment 5) In the present embodiment, a display device according to one aspect of the present invention will be described.

[0325] The display device of the present embodiment can be a high-definition display device. Therefore, the display device of the present embodiment can be used, for example, in the display units of information terminals (wearable devices) such as wristwatch type and bracelet type, as well as in VR devices such as head-mounted displays (HMDs) and in the display units of wearable devices that can be worn on the head such as glasses-type AR devices.

[0326] Also, the display device of the present embodiment can be a high-resolution display device or a large-sized display device. Therefore, the display device of the present embodiment can be used, for example, in electronic devices having a relatively large screen such as television devices, desktop or notebook personal computers, monitors for computers, 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 machines, portable information terminals, and audio playback devices.

[0327] [Display module] Fig. 13(A) 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, and may be any one of the display devices 100B to 100E2 described later.

[0328] The display module 280 includes a substrate 291 and a substrate 292. The display module 280 includes a display unit 281. The display unit 281 is an area for displaying an image in the display module 280, and is an area where light from each pixel provided in the pixel unit 284 described later can be visually recognized.

[0329] Fig. 13(B) shows a perspective view schematically showing the configuration on the substrate 291 side. On the substrate 291, a circuit unit 282, a pixel circuit unit 283 on the circuit unit 282, and a pixel unit 284 on the pixel circuit unit 283 are stacked. In addition, a terminal unit 285 for connecting to the FPC 290 is provided in a portion that does not overlap with the pixel unit 284 on the substrate 291. The terminal unit 285 and the circuit unit 282 are electrically connected by a wiring unit 286 formed of a plurality of wirings.

[0330] The pixel unit 284 includes a plurality of pixels 284a arranged periodically. An enlarged view of one pixel 284a is shown on the right side of Fig. 13(B). Various configurations described in the previous embodiments can be applied to the pixel 284a.

[0331] The pixel circuit unit 283 includes a plurality of pixel circuits 283a arranged periodically.

[0332] One pixel circuit 283a is a circuit that controls the driving of a plurality of elements included in one pixel 284a.

[0333] The circuit section 282 has a circuit for driving each pixel circuit 283a of the pixel circuit section 283. For example, it preferably has one or both of a gate line driving circuit and a source line driving circuit. In addition, it may have at least one of an arithmetic circuit, a memory circuit, a power supply circuit, and the like.

[0334] The FPC 290 functions as a wiring for supplying a video signal, a power supply potential, or the like from the outside to the circuit section 282. Also, an IC may be mounted on the FPC 290.

[0335] 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 below the pixel section 284, so that the aperture ratio (effective display area ratio) of the display section 281 can be made extremely high.

[0336] Since such a display module 280 is extremely high-definition, it can be suitably used for VR devices such as HMDs or glasses-type AR devices. For example, even in the case of a configuration in which the display section of the display module 280 is viewed through a lens, since the display module 280 has an extremely high-definition display section 281, no pixels can be seen even when the display section is enlarged by the lens, and a highly immersive display can be performed. Also, the display module 280 is not limited to this, and can be suitably used for electronic devices having a relatively small display section.

[0337] [Display device 100A] The display device 100A shown in FIG. 14(A) has 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.

[0338] The substrate 301 corresponds to the substrate 291 in FIGS. 13(A) and 13(B). The transistor 310 is a transistor having a channel formation region in the substrate 301. As the substrate 301, for example, a semiconductor substrate such as a single crystal silicon substrate can be used. The transistor 310 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 in which the substrate 301 is doped with impurities and functions as a source or a drain. The insulating layer 314 is provided to cover the side surface of the conductive layer 311.

[0339] Also, an element isolation layer 315 is provided between two adjacent transistors 310 so as to be embedded in the substrate 301.

[0340] Also, an insulating layer 261 is provided to cover the transistor 310, and a capacitor 240 is provided on the insulating layer 261.

[0341] 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 a dielectric of the capacitor 240.

[0342] The conductive layer 241 is provided on the insulating layer 261 and is embedded in the insulating layer 254. The conductive layer 241 is electrically connected to one of the source or drain of the transistor 310 by a plug 271 embedded in the insulating layer 261. The insulating layer 243 is provided to cover the conductive layer 241. The conductive layer 245 is provided in a region overlapping the conductive layer 241 via the insulating layer 243.

[0343] Covering a capacity of 240, an insulating layer 255 is provided, an insulating layer 174 is provided on the insulating layer 255, and an insulating layer 175 is provided on the insulating layer 174. On the insulating layer 175, a light-emitting device 130R, a light-emitting device 130G, and a light-emitting device 130B are provided. An insulator is provided in the region between adjacent light-emitting devices.

[0344] An insulating layer 156R is provided so as to have a region overlapping with the side surface of the conductive layer 151R, an insulating layer 156G is provided so as to have a region overlapping with the side surface of the conductive layer 151G, and an insulating layer 156B is provided so as to have a region overlapping with the side surface of the conductive layer 151B. Also, 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.

[0345] The conductive layer 151R, the conductive layer 151G, and the conductive layer 151B are electrically connected to one of the source or drain of the transistor 310 by a plug 256 embedded in the insulating layer 243, the insulating layer 255, the insulating layer 174, and the insulating layer 175, a conductive layer 241 embedded in the insulating layer 254, and a plug 271 embedded in the insulating layer 261. Various conductive materials can be used for the plug.

[0346] Also, a protective layer 131 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. On the protective layer 131, the substrate 120 is bonded by a resin layer 122. Details of the components from the light-emitting device 130 to the substrate 120 can be referred to in Embodiment 4. The substrate 120 corresponds to the substrate 292 in FIG. 13(A).

[0347] FIG. 14(B) is a modified example of the display device 100A shown in FIG. 14(A). The display device shown in FIG. 14(B) has a colored layer 132R, a colored layer 132G, and a colored layer 132B, and the light-emitting device 130 has a region overlapping with one of the colored layer 132R, the colored layer 132G, and the colored layer 132B. In the display device shown in FIG. 14(B), 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.

[0348] [Display device 100B] FIG. 15 shows a perspective view of the display device 100B, and FIG. 16 shows a cross-sectional view of the display device 100C.

[0349] The display device 100B has a configuration in which a substrate 352 and a substrate 351 are bonded together. In FIG. 15, the substrate 352 is shown by a dashed line.

[0350] The display device 100B has a pixel portion 177, a connection portion 140, a circuit 356, a wiring 355, etc. FIG. 15 shows an example in which an IC 354 and an FPC 353 are mounted on the display device 100B. Therefore, the configuration shown in FIG. 15 can also be referred to as a display module having the display device 100B, an IC (integrated circuit), and an FPC. Here, a display device in which a connector such as an FPC is attached to the substrate of the display device, or a display device in which an IC is mounted on the substrate is called a display module.

[0351] The connection portion 140 is provided outside the pixel portion 177. The connection portion 140 may be singular or plural. The connection portion 140 has the common electrode of the light-emitting device and the conductive layer electrically connected thereto, and can supply a potential to the common electrode.

[0352] As the circuit 356, for example, a scanning line driving circuit can be used.

[0353] The wiring 355 has a function of supplying signals and power to the pixel portion 177 and the circuit 356. The signals and power are input to the wiring 355 from the outside via the FPC 353 or from the IC 354.

[0354] FIG. 15 shows an example in which the IC 354 is provided on the substrate 351 by a COG (Chip On Glass) method, a COF (Chip on Film) method, or the like. As the IC 354, for example, an IC having a scanning line driving circuit, a signal line driving circuit, or the like can be applied. Note that the display device 100B and the display module may be configured not to include an IC. Further, the IC may be mounted on the FPC by, for example, a COF method.

[0355] FIG. 16 shows an example of a cross section when a part of the region including the FPC 353, a part of the circuit 356, a part of the pixel portion 177, a part of the connection portion 140, and a part of the region including the end portion of the display device 100B in FIG. 15 are each cut, as the display device 100C.

[0356] [Display device 100C] The display device 100C shown in FIG. 16 includes a transistor 201, a transistor 205, a light-emitting device 130R that emits red light, a light-emitting device 130G that emits green light, and a light-emitting device 130B that emits blue light, etc. between the substrate 351 and the substrate 352.

[0357] Details of the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B can be referred to in Embodiment 4.

[0358] The light-emitting device 130R includes a conductive layer 224R, a conductive layer 151R on the conductive layer 224R, and a conductive layer 152R on the conductive layer 151R. The light-emitting device 130G includes a conductive layer 224G, a conductive layer 151G on the conductive layer 224G, and a conductive layer 152G on the conductive layer 151G. The light-emitting device 130B includes a conductive layer 224B, a conductive layer 151B on the conductive layer 224B, and a conductive layer 152B on the conductive layer 151B.

[0359] 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.

[0360] Regarding the conductive layer 224G, the conductive layer 151G, the conductive layer 152G, the insulating layer 156G in the light-emitting device 130G, and the conductive layer 224B, the conductive layer 151B, the conductive layer 152B, the insulating layer 156B in the light-emitting device 130B, since they are the same as the conductive layer 224R, the conductive layer 151R, the conductive layer 152R, the insulating layer 156R in the light-emitting device 130R, detailed description thereof will be omitted.

[0361] In the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, recesses are formed so as to cover the openings provided in the insulating layer 214. The layer 128 is embedded in the recesses.

[0362] The layer 128 has a function of filling and planarizing the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B. On the conductive layer 224R, the conductive layer 224G, the conductive layer 224B, and the layer 128, the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B that are electrically connected to the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B are provided. Therefore, the region overlapping the recesses of the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B can also be used as a light-emitting region, and the aperture ratio of the pixel can be increased.

[0363] The layer 128 may be an insulating layer or a conductive layer. Various inorganic insulating materials, organic insulating materials, and conductive materials can be appropriately used for the layer 128. In particular, the layer 128 is preferably formed using an insulating material, and particularly preferably formed using an organic insulating material. For example, the organic insulating material that can be used for the aforementioned insulating layer 127 can be applied to the layer 128.

[0364] A protective layer 131 is provided on the light-emitting device 130R, the light-emitting device 130G, and the light-emitting device 130B. The protective layer 131 and the substrate 352 are adhered via an adhesive layer 142. A light-shielding layer 157 is provided on the substrate 352. For sealing the light-emitting device 130, a solid-sealing structure, a hollow-sealing structure, or the like can be applied. In FIG. 16, the space between the substrate 352 and the substrate 351 is filled with the adhesive layer 142, and a solid-sealing structure is applied. Alternatively, the space may be filled with an inert gas (such as nitrogen or argon), and a hollow-sealing structure may be applied. At this time, the adhesive layer 142 may be provided so as not to overlap with the light-emitting device. Further, the space may be filled with a resin different from the adhesive layer 142 provided in a frame shape.

[0365] In FIG. 16, an example is shown in which the connection portion 140 has a conductive layer 224C obtained by processing the same conductive film as the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, a conductive layer 151C obtained by processing the same conductive film as the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, and a conductive layer 152C obtained by processing the same conductive film as the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B. Further, FIG. 16 shows an example in which an insulating layer 156C is provided so as to have a region overlapping the side surface of the conductive layer 151C.

[0366] The display device 100C is a top-emission type. The light emitted from the light-emitting device is emitted toward the substrate 352 side. It is preferable to use a material having high transmittance for visible light for the substrate 352. The pixel electrode contains a material that reflects visible light, and the counter electrode (common electrode 155) contains a material that transmits visible light.

[0367] On the substrate 351, an insulating layer 211, an insulating layer 213, an insulating layer 215, and an insulating layer 214 are provided in this order. A part of the insulating layer 211 functions as a gate insulating layer of each transistor. A part of the insulating layer 213 functions as a gate insulating layer of each transistor. The insulating layer 215 is provided to cover the transistor. The insulating layer 214 is provided to cover the transistor and has a function as a planarization layer. Note that the number of gate insulating layers and the number of insulating layers covering the transistor are not limited, and each may be a single layer or two or more layers.

[0368] As the insulating layer 211, the insulating layer 213, and the insulating layer 215, it is preferable to use an inorganic insulating film respectively.

[0369] An organic insulating layer is suitable for the insulating layer 214 that functions as a planarization layer.

[0370] The transistor 201 and the transistor 205 include a conductive layer 221 that functions as a gate, an insulating layer 211 that functions as a gate insulating layer, conductive layers 222a and 222b that function as a source and a drain, a semiconductor layer 231, an insulating layer 213 that functions as a gate insulating layer, and a conductive layer 223 that functions as a gate.

[0371] A connection portion 204 is provided in a region of the substrate 351 where the substrate 352 does not overlap. In the connection portion 204, a source electrode or a drain electrode of the transistor 201 is electrically connected to the FPC 353 via the conductive layer 166 and the connection layer 242. The conductive layer 166 is an example of a laminated structure including a conductive film obtained by processing the same conductive film as the conductive layer 224R, the conductive layer 224G, and the conductive layer 224B, a conductive film obtained by processing the same conductive film as the conductive layer 151R, the conductive layer 151G, and the conductive layer 151B, and a conductive film obtained by processing the same conductive film as the conductive layer 152R, the conductive layer 152G, and the conductive layer 152B. On the upper surface of the connection portion 204, the conductive layer 166 is exposed. Thereby, the connection portion 204 and the FPC 353 can be electrically connected via the connection layer 242.

[0372] It is preferable to provide a light-shielding layer 157 on the surface of the substrate 352 on the side of the substrate 351. The light-shielding layer 157 can be provided between adjacent light-emitting devices, at the connection portion 140, and in the circuit 356 or the like. In addition, various optical members can be arranged outside the substrate 352.

[0373] As the substrates 351 and 352, materials that can be used for the substrate 120 can be applied respectively.

[0374] As the adhesive layer 142, materials that can be used for the resin layer 122 can be applied.

[0375] As the connection layer 242, an anisotropic conductive film (ACF: Anisotropic Conductive Film), an anisotropic conductive paste (ACP: Anisotropic Conductive Paste), or the like can be used.

[0376] [Display device 100D] The display device 100D shown in FIG. 17 is mainly different from the display device 100C shown in FIG. 16 in that it is a bottom emission type display device.

[0377] The light emitted by the light-emitting device is emitted toward the substrate 351 side. It is preferable to use a material with high transmittance for visible light for the substrate 351. On the other hand, the light transmittance of the material used for the substrate 352 does not matter.

[0378] 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. In FIG. 17, an example is shown 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.

[0379] The light-emitting device 130R has a conductive layer 112R, a conductive layer 126R on the conductive layer 112R, and a conductive layer 129R on the conductive layer 126R.

[0380] 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.

[0381] For the conductive layers 112R, 112B, 126R, 126B, 129R, and 129B, materials with high transmittance to visible light are used respectively. It is preferable to use a material that reflects visible light for the second electrode 102.

[0382] In FIG. 17, although the light-emitting device 130G is not shown, the light-emitting device 130G is also provided.

[0383] Also, in FIG. 17 and the like, an example is shown in which the upper surface of the layer 128 has a flat portion, but the shape of the layer 128 is not particularly limited.

[0384] [Display device 100D2] The display device 100D2 shown in FIG. 18(A) is an example of a bottom emission type display device different from the display device 100D shown in FIG. 17. The display device 100D2 is different from the display device 100D in that it has an organic resin layer 180. In the figure, the reference numerals of the same components as those in FIG. 17 may be omitted, and the details thereof may be referred to the description of FIG. 17.

[0385] Also, FIG. 18(B) shows the top layout of the pixel 178 (pixel 178a and pixel 178b) having the sub-pixels 110 (sub-pixel 110R, sub-pixel 110G, sub-pixel 110B, sub-pixel 110W), and FIG. 18(C) shows a top view of the organic resin layer 180 in the region where the sub-pixels 110R and 110W included in the pixel 178 are formed. Note that the width between the light-shielding layers 317 is the width 110Rw in the light-emitting region of the sub-pixel 110R.

[0386] As shown in FIG. 18(A), the organic resin layer 180 is provided on the insulating layer 214. As shown in the region surrounded by the dashed-dotted line in FIG. 18(A) and FIG. 18(C), the organic resin layer 180 has concave portions 181 (concave portion 181a, concave portion 181b) having a curved surface in at least the region where sub-pixels are formed. Note that the concave portion 181 may be provided outside the light-emitting region like the concave portion 181c. By providing the concave portion 181c, light generated in the region overlapping with the light-shielding layer 317 or light that has traveled to the region overlapping with the light-shielding layer 317 is refracted and can be extracted from the light-emitting region, so that the light-emitting efficiency can be improved.

[0387] A plurality of the concave portions 181 may be formed in a matrix. The concave portion 181a and the concave portion 181b may be provided in contact with each other or may have a flat surface therebetween.

[0388] In addition, in FIG. 18, the upper surface shape of the concave portion is shown as a hexagon (FIG. 18(C)) and the cross-sectional shape is shown as a semi-circle (FIG. 18(A)), but other shapes may be used as necessary. For example, as the upper surface shape of the concave portion, polygons such as a triangle, a quadrilateral (including a rectangle and a square), a pentagon, etc., a shape in which the corners of these polygons are rounded, an ellipse, or a circle, etc. can be mentioned.

[0389] As the organic resin layer 180, an insulating layer having an organic material can be used. For example, as the organic resin layer 180, an acrylic resin, a polyimide resin, an epoxy resin, an imide resin, a polyamide resin, a polyimide amide resin, a silicone resin, a siloxane resin, a benzocyclobutene-based resin, a phenol resin, and precursors of these resins, etc. can be applied. Further, as the organic resin layer 180, an organic material such as polyvinyl alcohol (PVA), polyvinyl butyral, polyvinyl pyrrolidone, polyethylene glycol, polyglycerin, pullulan, water-soluble cellulose, or alcohol-soluble polyamide resin may be used.

[0390] In addition, a photosensitive resin can be used as the organic resin layer 180. A photoresist may be used as the photosensitive resin. As the photosensitive resin, a positive-type material or a negative-type material can be used.

[0391] 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.

[0392] In addition, a first electrode 101 (first electrodes 101R and 101W) is provided on the organic resin layer 180, and an organic compound layer 103 is provided on the first electrode 101. The ends of the first electrode 101 and the organic compound layer 103 may be covered with an insulating layer 127.

[0393] In addition, the first electrode 101 formed on the organic resin layer 180 has a concave portion similarly along the concave portion of the organic resin layer 180. Further, the organic compound layer 103 formed on the first electrode 101 has a concave portion similarly along the concave portion of the first electrode 101. Further, the common layer 104 formed on the organic compound layer 103 has a concave portion similarly along the concave portion of the organic compound layer 103. Further, the second electrode 102 formed on the common layer 104 has a concave portion similarly along the concave portion of the common layer 104. That is, the concave portions 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 that overlaps each other.

[0394] In addition, 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.

[0395] In FIG. 18(A), only the light-emitting devices 130W and 130R are illustrated, and the light-emitting devices 130G and 130B are not illustrated, but the light-emitting devices 130G and 130B are also provided.

[0396] [Display device 100E] The display device 100E shown in FIG. 19 is a modified example of the display device 100C shown in FIG. 16, and is mainly different from the display device 100C in that it has a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B.

[0397] In the display device 100E, the light-emitting device 130 has a region that overlaps with one of the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. The coloring layer 132R, the coloring layer 132G, and the coloring layer 132B can be provided on the surface of the substrate 351 on the side of the substrate 352. The ends of the coloring layer 132R, the ends of the coloring layer 132G, and the ends of the coloring layer 132B can overlap with the light-shielding layer 157.

[0398] In the display device 100E, the light-emitting device 130 can emit, for example, white light. Also, for example, the coloring layer 132R can transmit red light, the coloring layer 132G can transmit green light, and the coloring layer 132B can transmit blue light. Note that the display device 100E may be configured to have the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B between the protective layer 131 and the adhesive layer 142.

[0399] [Display device 100E2] The display device 100E2 shown in FIG. 20(A) is a modified example of the display device 100E shown in FIG. 19, and has microlenses 182 on the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. In the figure, the reference numerals of the same components as those in FIG. 19 may be omitted, and the details thereof may be referred to the description of FIG. 19.

[0400] Further, FIG. 20(B) shows the top layout of pixels 178 (pixel 178a and pixel 178b) having sub-pixels 110 (sub-pixel 110R, sub-pixel 110G, and sub-pixel 110B), and FIG. 20(C) shows a top view of microlens 182 in the region where sub-pixels 110R, sub-pixel 110G, and sub-pixel 110B formed by pixel 178 are formed. Note that the region where the common electrode 155 contacts the organic compound layer 103 is the width 110Gw in the light-emitting region of sub-pixel 110G.

[0401] The display device 100E2 shown in FIG. 20(A) provides a planarization film 143 on the protective layer 131, and provides a coloring layer 132R, a coloring layer 132G, and a coloring layer 132B on the planarization film 143. A planarization film 144 is provided so as to cover the coloring layer 132R, the coloring layer 132G, and the coloring layer 132B. A microlens 182 is provided on the planarization film 144.

[0402] Note that as shown in FIG. 20(C), the microlens 182 may be provided for each sub-pixel in the region where the sub-pixels are formed.

[0403] Note that in FIG. 20(C), the top shape of the microlens 182 is shown as a hexagon, but it may be other shapes as needed. For example, the top shape of the microlens 182 may be a polygon such as a triangle, a quadrilateral (including a rectangle and a square), a pentagon, etc., a shape with rounded corners of these polygons, an ellipse, or a circle.

[0404] The microlens 182 can be formed using the same material as the organic resin layer 180.

[0405] This embodiment can be appropriately combined with other embodiments or examples. Also, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration examples can be appropriately combined.

[0406] (Embodiment 6) In this embodiment, an electronic device according to one aspect of the present invention will be described.

[0407] The electronic device of this embodiment has the display device of one aspect of the present invention in the display unit. The display device of one aspect of the present invention has low power consumption and high reliability. Therefore, it can be used in the display units of various electronic devices.

[0408] Examples of the electronic device include, for example, a television device, a desktop or notebook personal computer, a monitor for a computer, a digital signage, a large game machine such as a pachinko machine, etc., which are electronic devices equipped with a relatively large screen, and in addition, a digital camera, a digital video camera, a digital photo frame, a mobile phone, a portable game machine, a portable information terminal, an audio playback device, etc.

[0409] An example of a wearable device that can be worn on the head will be described with reference to FIGS. 21(A) to 21(D).

[0410] The electronic device 700A shown in FIG. 21(A) and the electronic device 700B shown in FIG. 21(B) each have a pair of display panels 751, a pair of housings 721, a communication unit (not shown), a pair of mounting parts 723, a control unit (not shown), an imaging unit (not shown), a pair of optical members 753, a frame 757, and a pair of nose pads 758.

[0411] The display device of one aspect of the present invention can be applied to the display panel 751. Therefore, an electronic device with high reliability can be obtained.

[0412] The electronic device 700A and the electronic device 700B can each project the image displayed on the display panel 751 onto the display area 756 of the optical member 753. Since the optical member 753 has translucency, the user can see the image displayed in the display area superimposed on the transmitted image viewed through the optical member 753.

[0413] The electronic device 700A and the electronic device 700B may be provided with a camera capable of imaging the front as an imaging unit. Further, the electronic device 700A and the electronic device 700B may each be provided with an acceleration sensor such as a gyro sensor to detect the orientation of the user's head and display an image corresponding to the orientation in the display area 756.

[0414] The communication unit has a wireless communication device, and the wireless communication device can supply, for example, a video signal. In addition to or instead of the wireless communication device, a connector to which a cable for supplying a video signal and a power supply potential can be connected may be provided.

[0415] Also, the electronic device 700A and the electronic device 700B are provided with a battery and can be charged by one or both of wireless and wired means.

[0416] The housing 721 may be provided with a touch sensor module.

[0417] As the touch sensor module, various touch sensors can be applied. For example, various methods such as a capacitance method, a resistive film method, an infrared method, an electromagnetic induction method, a surface acoustic wave method, or an optical method can be adopted. In particular, it is preferable to apply a capacitance method or optical method sensor to the touch sensor module.

[0418] The electronic device 800A shown in FIG. 21(C) and the electronic device 800B shown in FIG. 21(D) each have 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.

[0419] The display device according to one aspect of the present invention can be applied to the display unit 820. Therefore, a highly reliable electronic device can be obtained.

[0420] The display unit 820 is provided at a position inside the housing 821 where it can be visually recognized through the lens 832. Also, by displaying different images on the pair of display units 820, three-dimensional display using parallax can be performed.

[0421] It is preferable that the electronic devices 800A and 800B each have a mechanism capable of adjusting the left and right positions of the lens 832 and the display unit 820 so that they are at optimal positions according to the position of the user's eyes.

[0422] The user can wear the electronic device 800A or 800B on the head by the wearing unit 823.

[0423] The imaging unit 825 has a function of acquiring external information. The data acquired by the imaging unit 825 can be output to the display unit 820. An image sensor can be used for the imaging unit 825. Also, a plurality of cameras may be provided so as to be capable of corresponding to a plurality of angles of view such as telephoto and wide angle.

[0424] The electronic device 800A may have a vibration mechanism that functions as a bone conduction earphone.

[0425] The electronic devices 800A and 800B may each have an input terminal. A video signal from a video output device or the like and a cable for supplying power for charging a battery provided in the electronic device can be connected to the input terminal.

[0426] The electronic device according to one aspect of the present invention may have a function of performing wireless communication with the earphone 750.

[0427] Also, the electronic device may have an earphone unit. The electronic device 700B shown in FIG. 21(B) has an earphone unit 727. A part of the wiring connecting the earphone unit 727 and the control unit may be arranged inside the housing 721 or the wearing unit 723.

[0428] Similarly, the electronic device 800B shown in FIG. 21(D) has an earphone unit 827. For example, the earphone unit 827 and the control unit 824 can be configured to be wired to each other.

[0429] As described above, as the electronic device according to an aspect of the present invention, either the glasses type (electronic devices 700A, 700B, etc.) or the goggle type (electronic devices 800A, 800B, etc.) is suitable.

[0430] The electronic device 6500 shown in FIG. 22(A) is a portable information terminal that can be used as a smartphone.

[0431] The electronic device 6500 includes a housing 6501, a display unit 6502, a power button 6503, a button 6504, a speaker 6505, a microphone 6506, a camera 6507, a light source 6508, and the like. The display unit 6502 has a touch panel function.

[0432] The display device according to an aspect of the present invention can be applied to the display unit 6502. Therefore, a highly reliable electronic device can be obtained.

[0433] FIG. 22(B) is a schematic cross-sectional view including an end portion on the microphone 6506 side of the housing 6501.

[0434] A protective member 6510 having translucency is provided on the display surface side of the housing 6501, and a display panel 6511, an optical member 6512, a touch sensor panel 6513, a printed circuit board 6517, a battery 6518, and the like are arranged in a space surrounded by the housing 6501 and the protective member 6510.

[0435] The display panel 6511, the optical member 6512, and the touch sensor panel 6513 are fixed to the protective member 6510 by an adhesive layer (not shown).

[0436] In a region outside the display unit 6502, a part of the display panel 6511 is folded back, and an FPC 6515 is connected to the folded-back portion. An IC 6516 is mounted on the FPC 6515. The FPC 6515 is connected to a terminal provided on a printed circuit board 6517.

[0437] The display device according to one aspect of the present invention can be applied to the display panel 6511. Therefore, an extremely lightweight electronic device can be realized. Further, since the display panel 6511 is extremely thin, a large-capacity battery 6518 can be mounted while suppressing the thickness of the electronic device. Further, by folding back a part of the display panel 6511 and arranging a connection portion with the FPC 6515 on the back side of the pixel portion, a narrow bezel electronic device can be realized.

[0438] An example of a television device is shown in FIG. 22(C). In the television device 7100, a display unit 7000 is incorporated in a housing 7171. Here, a configuration in which the housing 7171 is supported by a stand 7173 is shown.

[0439] The display device according to one aspect of the present invention can be applied to the display unit 7000. Therefore, a highly reliable electronic device can be obtained.

[0440] The operation of the television device 7100 shown in FIG. 22(C) can be performed by an operation switch provided in the housing 7171 and a separate remote control operation unit 7151.

[0441] An example of a notebook personal computer is shown in FIG. 22(D). The notebook personal computer 7200 has a housing 7211, a keyboard 7212, a pointing device 7213, an external connection port 7214, and the like. A display unit 7000 is incorporated in the housing 7211.

[0442] The display device according to one aspect of the present invention can be applied to the display unit 7000. Therefore, a highly reliable electronic device can be obtained.

[0443] Figures 22(E) and 22(F) show an example of digital signage.

[0444] The digital signage 7300 shown in Fig. 22(E) includes a housing 7301, a display unit 7000, a speaker 7303, etc. Furthermore, it can have an LED lamp, operation keys (including a power switch or an operation switch), connection terminals, various sensors, a microphone, etc.

[0445] Fig. 22(F) shows a digital signage 7400 attached to a cylindrical pillar 7401. The digital signage 7400 has a display unit 7000 provided along the curved surface of the pillar 7401.

[0446] In Figs. 22(E) and 22(F), the display device according to one aspect of the present invention can be applied to the display unit 7000. Therefore, it can be made into a highly reliable electronic device.

[0447] The larger the display unit 7000 is, the more information can be provided at one time. Also, the larger the display unit 7000 is, the more likely it is to catch people's eyes. For example, the advertising effect can be enhanced.

[0448] Also, as shown in Figs. 22(E) and 22(F), it is preferable that the digital signage 7300 or the digital signage 7400 can be linked by wireless communication with an information terminal 7311 or an information terminal 7411 such as a smartphone held by a user.

[0449] The electronic device shown in Figs. 23(A) to 23(G) includes a housing 9000, a display unit 9001, a speaker 9003, operation keys 9005 (including a power switch or an operation switch), connection terminals 9006, a sensor 9007 (including a function of measuring force, displacement, position, speed, acceleration, angular velocity, rotation speed, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, power, radiation, flow rate, humidity, gradient, vibration, odor or infrared rays), a microphone 9008, etc.

[0450] The electronic devices shown in FIGS. 23(A) to 23(G) have various functions. For example, they can have functions such as displaying various information (still images, moving images, text images, etc.) on a display unit, a touch panel function, a function of displaying a calendar, date, or time, etc., a function of controlling processing by various software (programs), a wireless communication function, a function of reading and processing programs or data recorded on a recording medium, etc.

[0451] Details of the electronic devices shown in FIGS. 23(A) to 23(G) will be described below.

[0452] FIG. 23(A) is a perspective view showing a portable information terminal 9171. The portable information terminal 9171 can be used as, for example, a smartphone. Note that the portable information terminal 9171 may be provided with a speaker 9003, a connection terminal 9006, or a sensor 9007, etc. Also, the portable information terminal 9171 can display character and image information on a plurality of its surfaces. FIG. 23(A) shows an example in which three icons 9050 are displayed. Also, information 9051 indicated by a dashed rectangle can be displayed on another surface of the display unit 9001. Examples of the information 9051 include notifications of incoming calls such as e-mails, SNS, and phone calls, titles of e-mails or SNS, etc., sender names, dates, times, remaining battery levels, radio wave intensities, etc. Or, icons 9050 etc. may be displayed at the position where the information 9051 is displayed.

[0453] FIG. 23(B) is a perspective view showing a portable information terminal 9172. The portable information terminal 9172 has a function of displaying information on three or more surfaces of the display unit 9001. Here, an example is shown in which information 9052, information 9053, and information 9054 are respectively displayed on different surfaces. For example, the user can also confirm the information 9053 displayed at a position where it can be observed from above the portable information terminal 9172 in a state where the portable information terminal 9172 is stored in the breast pocket of a piece of clothing.

[0454] FIG. 23(C) is a perspective view showing a tablet terminal 9173. As an example, the tablet terminal 9173 is capable of executing various applications such as mobile phones, e-mails, text 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 surface of the housing 9000, and an operation key 9005 as an operation button on the left side surface of the housing 9000, and a connection terminal 9006 on the bottom surface.

[0455] FIG. 23(D) is a perspective view showing a wristwatch-type portable information terminal 9200. The portable information terminal 9200 can be used, for example, as a smart watch (registered trademark). Also, the display unit 9001 is provided with a curved display surface, and display can be performed along the curved display surface. Further, the portable information terminal 9200 can also make hands-free calls by communicating with, for example, a wirelessly communicable headset. In addition, the portable information terminal 9200 can also perform data transmission and charging mutually with other information terminals through the connection terminal 9006. Note that the charging operation may be performed by wireless power supply.

[0456] FIGS. 23(E) to 23(G) are perspective views showing a foldable portable information terminal 9201. FIG. 23(E) shows the portable information terminal 9201 in an unfolded state, FIG. 23(G) shows the folded state, and FIG. 23(F) is a perspective view of a state in the process of changing from one of FIGS. 23(E) and 23(G) to the other. The portable information terminal 9201 has excellent portability in the folded state and excellent display comprehensibility due to a seamless wide display area in the unfolded state. The display unit 9001 included in the portable information terminal 9201 is supported by three housings 9000 connected by a hinge 9055. For example, the display unit 9001 can be bent with a curvature radius of 0.1 mm or more and 150 mm or less.

[0457] This embodiment can be appropriately combined with other embodiments or examples. Also, in this specification, when a plurality of configuration examples are shown in one embodiment, the configuration examples can be appropriately combined.

Example

[0458] In this example, the results of investigating the orientation characteristics of the platinum complex in a light-emitting device using platinum complexes A to C as dopants are shown. The structural formulas and compound names of platinum complexes A to C are shown below.

[0459]

Chem.

[0460] Platinum complex A: (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1)platinum(II) (abbreviation: PtON-TBBI) Platinum complex B: (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[3,5-di(methyl-d3)-4-phenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz35dm4ppy-d6)) Platinum complex C: (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[3,5-di(methyl-d3)-4-tert-butylphenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz35dm4tBuppy-d6))

[0461] First, the inner product of the vector A connecting the two most distant atoms in the molecular arrangement of the lowest triplet excited state and the vector B of the transition dipole moment related to luminescence was obtained.

[0462] Here, the inner product of vector A and vector B was obtained for the three platinum complexes of the above platinum complex A, platinum complex B, and platinum complex C.

[0463] First, the most stable structures in the singlet ground state and the lowest triplet excited state were obtained by calculation.

[0464] For the structure for which quantum chemical calculations were to be performed, conformational analysis was carried out and sampled using MacroModel with the Maestro GUI manufactured by Schrödinger. Using the quantum chemical calculation software Jaguar, the most stable structure in the singlet ground state was calculated by the density functional method (DFT), and the structure of the most stable conformation was determined. In this structure, DYALL-2ZCVP_ZORA-J-PT-GEN++ was used for the Pt atom as the basis function, LACVP** was used for the other atoms, ωB97X-D (ω = 0.1) was used as the functional, and the time-dependent density functional method (TD-DFT) using the spin-free ZORA relativistic Hamiltonian was used to calculate the lowest triplet excited state as the excited state, and the most stable structure was obtained.

[0465] Subsequently, a single point energy calculation of the excited state using the spin-orbit ZORA relativistic Hamiltonian was carried out for the most stable structure in the lowest triplet excited state obtained, and vector B of the transition dipole moment related to luminescence was visualized.

[0466] Furthermore, vector A connecting the two most distant atoms in the same structure was defined so that the angle formed with vector B was 90° or less, and the angle formed with vector B was obtained. As an example, Fig. 2 shows a diagram showing the angles formed with each vector in platinum complex B. The results are also shown in Table 3.

[0467] [Table 3]

[0468] Platinum complex B and platinum complex C have an inner product of vector A and vector B of 4.0 or more, and are considered to greatly contribute to the improvement of the luminescence efficiency of the transition dipole moment.

[0469] Subsequently, the orientation parameter a of platinum complex A to platinum complex C in a light-emitting device using platinum complex A to platinum complex C as a light-emitting center substance was calculated from the results of measuring a light-emitting device for orientation measurement in which the front luminance was greatly reduced by adjusting the optical path length. In this example, in addition to the light-emitting device for orientation measurement, a normal light-emitting device that does not suppress the front luminance by the optical path length was also fabricated, and the data thereof is also shown.

[0470] The structural formula of the organic compound used in this example is shown below. A schematic diagram of the device structure of the light-emitting device for orientation measurement is shown in Fig. 24.

[0471]

Chemical formula

[0472] (Method for manufacturing light-emitting device 1Aa) Light-emitting device 1Aa is a light-emitting device for orientation measurement that uses platinum complex A as a light-emitting center substance and makes it easy to obtain the value of a representing the orientation state by forming a film thickness adjustment layer.

[0473] First, 70 nm of indium tin oxide (ITSO) containing silicon oxide was laminated on a glass substrate by sputtering to form a first electrode 101 having a size of 2 mm × 2 mm. The first electrode 101 functions as an anode.

[0474] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water.

[0475] Thereafter, about 1×10 -4The substrate was introduced into a vacuum evaporation apparatus whose interior was depressurized to Pa, and after vacuum baking at 170 °C for 30 minutes in the heating chamber of the vacuum evaporation apparatus, the substrate was allowed to cool for about 30 minutes.

[0476] Next, the substrate was fixed to a holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode 101 was formed faced downward. On the inorganic insulating film and the first electrode 101, N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) with a molecular weight of 672 and containing fluorine were co-evaporated at a weight ratio of 1:0.03 (= PCBBiF:OCHD-003) to form a hole injection layer 111.

[0477] On the hole injection layer 111, 30 nm of PCBBiF was evaporated to form a first hole transport layer, and then 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz) represented by the above structural formula (ii) was evaporated at 5 nm to form a second hole transport layer, thereby forming a hole transport layer 112. Note that the second hole transport layer also functions as an electron blocking layer.

[0478] Subsequently, on the hole transport layer 112, 9,9'-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2) represented by the above structural formula (iii), PSiCzCz, and a platinum complex A (PtON-TBBI) were co-evaporated at a weight ratio of 0.45:0.45:0.10 (= SiTrzCz2:PSiCzCz:PtON-TBBI) to form a light-emitting layer 113.

[0479] Subsequently, 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz) represented by the above structural formula (v) was deposited to a thickness of 5 nm to form a first electron transport layer. Subsequently, 2,2'-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the above structural formula (vi) was deposited to a thickness of 20 nm to form a second electron transport layer, thereby forming the electron transport layer 114.

[0480] Subsequently, lithium oxide (Li 2 O) was deposited to a thickness of 0.1 nm to form the electron injection layer 115.

[0481] Thereafter, 2 nm of copper phthalocyanine was formed, and 4,4',4''-(benzene-1,3,5-triyl)tris(dibenzothiophene) (abbreviation: DBT3P-II) represented by the above structural formula (vii) and molybdenum(VI) oxide (MoO 3 ) were formed to a thickness of 55 nm at a weight ratio of 1:0.5 (= DBT3P-II:MoO 3 ) to form the film thickness adjustment layer 217.

[0482] Thereafter, aluminum (Al) was deposited to a thickness of 200 nm to form the second electrode 102.

[0483] Subsequently, in a glove box under a nitrogen atmosphere, the light-emitting device was sealed with a glass substrate so as not to be exposed to the atmosphere (application of a UV-curable sealing material around the element, irradiation of only the sealing material with UV so as not to irradiate the light-emitting device, and heat treatment at 80 °C for 1 hour under atmospheric pressure), thereby forming the light-emitting device 1Aa.

[0484] (Method for manufacturing the light-emitting device 1Ab) The light-emitting device 1Ab is a light-emitting device having a platinum complex A as a light-emitting center substance. Since the light-emitting device 1Ab and the light-emitting device 1Aa are devices that differ only in the presence or absence of the film thickness adjustment layer in their configurations and manufacturing methods, the orientation state of the light-emitting center substance in the light-emitting layer is the same.

[0485] The light-emitting device 1Ab was fabricated in the same manner as the light-emitting device 1Aa, except that the film thickness adjustment layer 217 was not formed, and after forming the electron injection layer 115, the second electrode 102 was formed immediately thereafter.

[0486] (Fabrication method of the light-emitting device 1Ba) The light-emitting device 1Ba is a light-emitting device for orientation measurement that uses a platinum complex B as a light-emitting center substance and makes it easier to obtain the value of a representing the orientation state by forming a film thickness adjustment layer.

[0487] The light-emitting device 1Ba was fabricated in the same manner as the light-emitting device 1Aa, except that the platinum complex A in the light-emitting device 1Aa was changed to a platinum complex B (Pt(mmtBubOcz35dm4ppy-d6)).

[0488] (Fabrication method of the light-emitting device 1Bb) The light-emitting device 1Bb is a light-emitting device that uses a platinum complex B as a light-emitting center substance. Since the light-emitting device 1Bb and the light-emitting device 1Ba are devices that differ only in the presence or absence of a film thickness adjustment layer in their configurations and fabrication methods, the orientation state of the light-emitting center substance in the light-emitting layer is the same.

[0489] The light-emitting device 1Bb was fabricated in the same manner as the light-emitting device 1Ba, except that the film thickness adjustment layer 217 was not formed, and after forming the electron injection layer 115, the second electrode 102 was formed immediately thereafter.

[0490] (Fabrication method of the light-emitting device 1Ca) The light-emitting device 1Ca is a light-emitting device for orientation measurement that uses a platinum complex C as a light-emitting center substance and makes it easier to obtain the value of a representing the orientation state by forming a film thickness adjustment layer.

[0491] The light-emitting device 1Ca was fabricated in the same manner as the light-emitting device 1Aa, except that the platinum complex A in the light-emitting device 1Aa was changed to a platinum complex C (Pt(mmtBubOcz35dm4tBuppy-d6)).

[0492] (Fabrication method of the light-emitting device 1Cb) The light-emitting device 1Cb is a light-emitting device using a platinum complex C as a light-emitting center substance. Since the light-emitting device 1Cb and the light-emitting device 1Ca are devices that differ only in the presence or absence of a film thickness adjustment layer in their configurations and manufacturing methods, the orientation state of the light-emitting center substance in the light-emitting layer is the same.

[0493] The light-emitting device 1Cb was fabricated in the same manner as the light-emitting device 1Ca, except that the film thickness adjustment layer 217 was not formed, and the second electrode 102 was formed immediately after the electron injection layer 115 was formed.

[0494] The device structures of the light-emitting devices 1Aa, 1Ab, 1Ba, 1Bb, 1Ca, and 1Cb are shown below.

[0495]

Table 4

[0496] The luminance-current density characteristics of the light-emitting devices 1Aa and 1Ab are shown in Fig. 25, the current efficiency-current density characteristics are shown in Fig. 26, the luminance-voltage characteristics are shown in Fig. 27, the current density-voltage characteristics are shown in Fig. 28, the external quantum efficiency-current density characteristics are shown in Fig. 29, and the electroluminescence spectrum is shown in Fig. 30.

[0497] The luminance-current density characteristics of the light-emitting devices 1Ba and 1Bb are shown in Fig. 31, the current efficiency-current density characteristics are shown in Fig. 32, the luminance-voltage characteristics are shown in Fig. 33, the current density-voltage characteristics are shown in Fig. 34, the external quantum efficiency-current density characteristics are shown in Fig. 35, and the electroluminescence spectrum is shown in Fig. 36.

[0498] The luminance-current density characteristics of the light-emitting devices 1Ca and 1Cb are shown in Fig. 37, the current efficiency-current density characteristics are shown in Fig. 38, the luminance-voltage characteristics are shown in Fig. 39, the current density-voltage characteristics are shown in Fig. 40, the external quantum efficiency-current density characteristics are shown in Fig. 41, and the electroluminescence spectrum is shown in Fig. 42.

[0499] Also, the voltages, currents, current densities, CIE chromaticities, current efficiencies, external quantum efficiencies, and blue indices (BI) of the light-emitting devices 1Aa, 1Ab, 1Ba, 1Bb, 1Ca, and 1Cb near 1000 cd / cm 2 are shown below. For the measurement of luminance, CIE chromaticity, and electroluminescence spectrum, a spectro-radiometer (Topcon Corporation, SR-UL1R) was used and the measurements were made at room temperature.

[0500]

Table 5

[0501]

Table 6

[0502]

Table 7

[0503] From FIGS. 25 to 42 and Tables 5 to 7, it was found that for the light-emitting devices 1Aa, 1Ba, and 1Ca, the front luminance was attenuated by the film thickness adjustment layer, resulting in a decrease in luminous efficiency. Also, it was found that the light-emitting devices 1Ab, 1Bb, and 1Cb all exhibit better luminous efficiency than the light-emitting devices 1Aa, 1Ba, and 1Ca. In particular, it was found that the light-emitting devices 1Bb and 1Cb exhibit very good efficiency and BI.

[0504] Subsequently, the alignment characteristics of the light-emitting devices 1Aa, 1Ba, and 1Ca were measured and calculated.

[0505] First, as shown in Fig. 43, while tilting a substrate provided with a light-emitting device for orientation measurement (any one of light-emitting device 1Aa, light-emitting device 1Ba, and light-emitting device 1Ca) from θ = 0° to 80° with respect to a detector (Hamamatsu Photonics - multi-channel spectrometer PMA-12) by 1° each, the EL emission spectrum was measured, and the angular dependence of the spectral shape of the EL emission was measured. In this measurement, a linear polarizer (Glan-Taylor polarizing prism) was inserted perpendicular to the substrate surface between the light-emitting device for measurement and the detector, and the spectrum of only the P-polarized light was measured by removing the S-polarized light from the light emitted by the light-emitting device for orientation measurement.

[0506] Figs. 44 to 46 show graphs representing the area intensity from 420 nm to 750 nm of the EL emission spectrum at an angle (θ) on the vertical axis and the angle (θ) of the substrate with respect to the detector on the horizontal axis. Fig. 44 shows the results for light-emitting device 1Aa, Fig. 45 shows the results for light-emitting device 1Ba, and Fig. 46 shows the results for light-emitting device 1Ca.

[0507] In the figures, the graph shown as □ plots is the measured value, and the graphs shown as solid and dashed lines are the calculation results in setfos, which is an organic device simulator. The calculation was performed by inputting the measured values of the film thickness, refractive index, and extinction coefficient of each layer used in the device, the measured value of the emission spectrum of the dopant, the position and width of the emission region, and the orientation parameter a.

[0508] Among these, the film thickness, refractive index, and extinction coefficient of each layer were measured using a spectroscopic ellipsometer (M-2000U manufactured by J.A. Woollam Japan Co., Ltd.). For the measurement, a film formed by vacuum deposition of 50 nm of the material on a quartz substrate was used.

[0509] The emission spectrum of the dopant was measured using a detector (Hamamatsu Photonics - multi-channel spectrometer PMA-12). For the measurement, a film formed by co-evaporation deposition to a film thickness of 50 nm of a film having the same composition as the emission layer of the light-emitting device for orientation measurement on a quartz substrate was used.

[0510] In the calculation by setfos, the emission region is further set. In the light-emitting device 1Aa, assuming a state (gaussian) of the emission region where the recombination probability shows a Gaussian decay curve with respect to the cathode direction, with the interface between the hole transport layer and the light-emitting layer as the vertex, it is set that the emission region spreads such that the standard deviation σ of the Gaussian function is 15 nm. In the light-emitting device 1Ba, assuming a state (gaussian) of the emission region where the recombination probability shows a Gaussian decay curve with respect to the cathode and anode directions, with a point located 3.5 nm from the interface between the hole transport layer and the light-emitting layer in the cathode direction as the vertex, it is set that the emission region spreads such that the standard deviation σ of the Gaussian function is 8.5 nm. In the light-emitting device 1Ca, assuming a state (gaussian) of the emission region where the recombination probability shows a Gaussian decay curve with respect to the cathode direction, with the interface between the hole transport layer and the light-emitting layer as the vertex, it is set that the emission region spreads such that the standard deviation σ of the Gaussian function is 11 nm. The reason for the different settings of the emission region in each light-emitting device is that the carrier trapping properties in the light-emitting layer are different for each platinum complex, and the recombination region of the carriers also changes accordingly.

[0511] Thereby, for each orientation parameter a, the angular dependence of the area intensity of the emission spectrum can be calculated. The light-emitting device 1Aa showed a good agreement with the graph of a = 0.26, the light-emitting device 1Ba showed a good agreement with the graph of a = 0.21, and the light-emitting device 1Ca showed a good agreement with the graph of a = 0.22.

[0512] From the above results, it was found that the light-emitting devices 1Bb and 1Cb have a platinum complex, which is the light-emitting center substance in the light-emitting layer, with an orientation closer to the horizontal orientation than the light-emitting device 1Ab.

[0513] From Tables 5 to 7 and Figures 25 to 42, the efficiencies of the light-emitting devices 1Bb and 1Cb showed better results than the efficiency of the light-emitting device 1Ab, and showed a good agreement with the calculated results of the inner product value of vector A and vector B and the orientation parameter a.

[0514] Thus, it was found that platinum complex B and platinum complex C are more orientationally excellent than platinum complex A from the orientation parameter a. As shown in Table 3, this is considered to be correlated with the difference in the inner product between vector A and vector B. Platinum complex B and platinum complex C have a structure that greatly contributes to improving the emission efficiency of the transition dipole moment. An emission device or an emission device using a material for an emission device or a material for an emission device containing platinum complex B and platinum complex C can be an emission device or an emission device with good emission efficiency.

[0515] Note that the efficiency improvement effect due to the difference in the molecular orientation parameter a of the light-emitting device 1Bb or the light-emitting device 1Cb with respect to the light-emitting device 1Ab is 5% to 7%. The main factor for the efficiency improvement effect in these light-emitting devices is considered to be the large inner product between vector A and vector B.

Example

[0516] In this example, the manufacturing methods and characteristics of the light-emitting devices 2a and 2b, which are light-emitting devices according to one aspect of the present invention, and the comparative light-emitting device 2, which is a comparative light-emitting device, will be described in detail. The structural formulas of the main compounds used in the light-emitting device 2a, the light-emitting device 2b, and the comparative light-emitting device 2 are shown below.

[0517]

Chemical formula

[0518] (Manufacturing method of the light-emitting device 2a) First, 100 nm of silver (Ag) and then 10 nm of indium tin oxide (ITSO) containing silicon oxide were laminated on a glass substrate by sputtering to form a first electrode 101 with a size of 2 mm × 2 mm. Note that the first electrode 101 functions as an anode.

[0519] Next, as a pretreatment for forming a light-emitting device on the substrate, the substrate surface was washed with water.

[0520] Subsequently, the substrate was introduced into a vacuum evaporation apparatus whose interior was evacuated to approximately 1×10 -4 Pa, and in the heating chamber of the vacuum evaporation apparatus, vacuum baking was performed at 170°C for 30 minutes, and then the substrate was allowed to cool for approximately 30 minutes.

[0521] Next, the substrate was fixed to a holder provided in the vacuum evaporation apparatus so that the surface on which the first electrode 101 was formed faced downward. Onto the inorganic insulating film and the first electrode 101, N-(biphenyl-4-yl)-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-9,9-dimethyl-9H-fluorene-2-amine (abbreviation: PCBBiF) represented by the above structural formula (i) and an electron acceptor material (OCHD-003) containing fluorine with a molecular weight of 672 were co-evaporated at a weight ratio of 1:0.03 (=PCBBiF:OCHD-003) to form a hole injection layer 111 with a thickness of 10 nm.

[0522] On the hole injection layer 111, 120 nm of PCBBiF was evaporated to form a first hole transport layer. Subsequently, 9-[3-(triphenylsilyl)phenyl]-3,9'-bi-9H-carbazole (abbreviation: PSiCzCz) represented by the above structural formula (ii) was evaporated at a thickness of 5 nm to form a second hole transport layer, thereby forming a hole transport layer 112. Note that the second hole transport layer also functions as an electron blocking layer.

[0523] Subsequently, on the hole transport layer 112, 9,9’-{6-[3-(triphenylsilyl)phenyl]-1,3,5-triazine-2,4-diyl}bis(9H-carbazole) (abbreviation: SiTrzCz2) represented by the above structural formula (iii), PSiCzCz, and (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[3,5-di(methyl-d3)-4-phenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz35dm4ppy-d6)) (platinum complex B in Example 1) represented by the above structural formula (iv) were co-evaporated at a weight ratio of 0.45:0.45:0.10 (=SiTrzCz2:PSiCzCz:Pt(mmtBubOcz35dm4ppy-d6)) to a thickness of 35 nm to form the light-emitting layer 113.

[0524] After that, 2-phenyl-4,6-bis[3-(triphenylsilyl)phenyl]-1,3,5-triazine (abbreviation: mSiTrz) represented by the above structural formula (v) was evaporated to a thickness of 5 nm to form the first electron transport layer. Subsequently, 2,2’-(1,3-phenylene)bis(9-phenyl-1,10-phenanthroline) (abbreviation: mPPhen2P) represented by the above structural formula (vi) was evaporated to a thickness of 20 nm to form the second electron transport layer, thereby forming the electron transport layer 114.

[0525] Subsequently, lithium fluoride (LiF) was evaporated to a thickness of 1 nm to form the electron injection layer 115. Thereafter, silver (Ag) and magnesium (Mg) were co-evaporated at a volume ratio of 1:0.1 (=Ag:Mg) to a film thickness of 15 nm to form the second electrode 102. Further, 4,4’,4’’-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviation: DBT3P-II) represented by the above structural formula (vii) was formed into a film with a thickness of 70 nm as a cap layer on the second electrode.

[0526] Subsequently, in a glove box under a nitrogen atmosphere, an operation of sealing with a glass substrate was performed so that the light-emitting device was not exposed to the atmosphere (application of a UV-curable sealing material around the element, treatment of irradiating only the sealing material with UV so as not to irradiate the light-emitting device, and heat treatment at 80 °C for 1 hour under atmospheric pressure), and the light-emitting device 2a was formed.

[0527] (Method for manufacturing the light-emitting device 2b) The light-emitting device 2b was produced in the same manner as the light-emitting device 2a, except that Pt(mmtBubOcz35dm4ppy-d6) in the light-emitting device 2a was changed to platinum(II) (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[3,5-di(methyl-d3)-4-tert-butylphenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC) (abbreviation: Pt(mmtBubOcz35dm4tBuppy-d6)) (platinum complex C in Example 1) represented by the above structural formula (viii).

[0528] (Method for manufacturing the comparative light-emitting device 2) The comparative light-emitting device 2 was produced in the same manner as the light-emitting device 2a, except that Pt(mmtBubOcz35dm4ppy-d6) in the light-emitting device 2a was changed to platinum(II) (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-(4-tert-butyl-2-pyridinyl-κN)carbazole-2,1-diyl-κC1) (abbreviation: PtON-TBBI) (platinum complex A in Example 1) represented by the above structural formula (ix).

[0529] The device structures of the light-emitting device 2a, the light-emitting device 2b, and the comparative light-emitting device 2 are shown below.

[0530]

Table 8

[0531] The luminance-current density characteristics of the light-emitting devices 2a, 2b and the comparative light-emitting device 2 are shown in Fig. 47, the luminance-voltage characteristics are shown in Fig. 48, the current efficiency-current density characteristics are shown in Fig. 49, the current density-voltage characteristics are shown in Fig. 50, the blue index (BI)-current density characteristics are shown in Fig. 51, and the electroluminescence spectrum is shown in Fig. 52.

[0532] Also, the values of voltage, current, current density, CIE chromaticity, current efficiency, and blue index (BI) near 1000 cd / cm 2 are shown below. For the measurement of luminance, CIE chromaticity, and electroluminescence spectrum, a spectro-radiometer (Topcon Corporation, SR-UL1R) was used and the measurement was carried out at room temperature.

[0533] [Table 9]

[0534] From Figs. 47 to 52 and Table 9, it was found that the light-emitting devices 2a and 2b are light-emitting devices showing good current efficiency and blue index.

[0535] Also, the normalized luminance time change characteristics of the light-emitting devices 2a, 2b and the comparative light-emitting device 2 are shown in Fig. 53. In this measurement, the initial luminance was set assuming that a full-color display device was fabricated using each light-emitting device, and when white (D65) display was performed on the display device, the luminance was set to the luminance for obtaining 5000 cd / m 2 Note that the aperture ratio of the display device was 13.4% for red, 13.4% for green, and 26.7% for blue. Also, the initial luminance of each light-emitting device, the corresponding current density, and the times (LT90, LT50) to reach 90% and 50% of the initial luminance were summarized in the following table.

[0536] [Table 10]

[0537] As shown in FIG. 53, it was found that the light-emitting devices 2a and 2b of one embodiment of the present invention are light-emitting devices with a small change in normalized luminance over time and good reliability as compared with the comparative light-emitting device 2.

[0538] (Reference Example 1) ≪Synthesis Example 1≫ In this reference example, a synthesis example of the organometallic complex used as the platinum complex B in the examples, (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[3,5-di(methyl-d3)-4-phenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz35dm4ppy-d6)) will be specifically exemplified.

[0539]

Chemical formula

[0540] <Step 1: Synthesis of 2-fluoro-3,5-dimethyl-4-phenylpyridine> First, 4.9 g of 2-fluoro-4-iodo-3,5-dimethylpyridine, 2.7 g of phenylboronic acid, 8.3 g of potassium carbonate, 80 mL of 1,4-dioxane, and 20 mL of water were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. After degassing by stirring the inside of the flask under reduced pressure, tetrakis(triphenylphosphine)palladium(0) (abbreviation: Pd(PPh 3 ) 4 ) 1.4 g was added, and the reaction was carried out by stirring at 85°C for 23 hours.

[0541] After a predetermined time had elapsed, extraction with toluene was performed. The obtained residue was purified by silica gel column chromatography using toluene as the developing solvent to obtain the target product (pale yellow solid, yield 3.6 g, yield 90%). The synthesis scheme of Step 1 is shown.

[0542]

Chemical formula

[0543] <Step 2: Synthesis of 2-Bromo-9-(3,5-dimethyl-4-phenylpyridin-2-yl)carbazole> Next, 3.6 g of 2-fluoro-3,5-dimethyl-4-phenylpyridine obtained in Step 1 above, 4.6 g of 2-bromocarbazole, 12 g of cesium carbonate, and 40 mL of N-methyl-2-pyrrolidone (abbreviation: NMP) were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. Then, the reaction was carried out by stirring at 120°C for 18.5 hours.

[0544] After a predetermined time had elapsed, extraction was performed with toluene. The obtained residue was purified by silica gel column chromatography using hexane:toluene = 1:5 as the developing solvent to obtain the target product (colorless oil, yield 6.9 g, yield 90%). The synthesis scheme of Step 2 is shown.

[0545]

Chemical formula

[0546] <Step 3: Synthesis of 2-Bromo-9-[3,5-di(methyl-d 3 )-4-phenylpyridin-2-yl]carbazole> Next, 6.9 g of 2-bromo-9-(3,5-dimethyl-4-phenylpyridin-2-yl)carbazole obtained in Step 2 above, 23 mL of dimethyl sulfoxide-d 6 (abbreviation: DMSO-d 6 ) and 0.93 g of sodium tert-butoxide were placed in an eggplant-shaped flask, and the inside was purged with nitrogen. Then, the reaction was carried out by stirring at room temperature for 16 hours.

[0547] After a predetermined time had elapsed, extraction was performed with toluene. The obtained residue was purified by silica gel column chromatography using hexane:toluene = 1:5 as the developing solvent to obtain the target product (white solid, yield 5.8 g, yield 83%). The synthesis scheme of Step 3 is shown.

[0548] [Chemical formula]

[0549] <Step 4: Synthesis of 2-Hydroxy-9-[3,5-Bis(Methyl-d 3 )-4-Phenylpyridin-2-Yl]Carbazole> Next, 5.8 g of 2-Bromo-9-[3,5-Bis(Methyl-d 3 )-4-Phenylpyridin-2-Yl]Carbazole obtained in Step 3 above, 2.7 g of sodium tert-butoxide, 54 mL of dimethyl sulfoxide, and 13 mL of water were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. After degassing by stirring under reduced pressure inside the flask, 0.066 g of copper(I) chloride (abbreviation: CuCl) and 0.22 g of N1,N2-Bis(4-Hydroxy-2,6-Dimethylphenyl)Oxalamide were added, and the reaction was carried out by stirring at 110 °C for 2 hours.

[0550] After a predetermined time had elapsed, extraction was performed with ethyl acetate. The obtained residue was purified by recrystallization from toluene to obtain the target product (pale orange solid, yield 4.0 g, yield 80%). The synthesis scheme of Step 4 is shown.

[0551] [Chemical formula]

[0552] <Step 5: Synthesis of 2-[3-(Benzimidazol-1-Yl)Phenoxy]-9-[3,5-Bis(Methyl-d 3 )-4-Phenylpyridin-2-Yl]Carbazole> Next, 2-Hydroxy-9-[3,5-Bis(Methyl-d 3)-[3,5-Bis(dimethyl-d)]-4-phenylpyridin-2-yl]carbazole 1.9 g, 1-(3-bromophenyl)benzimidazole 1.5 g, tripotassium phosphate 2.2 g, and dimethyl sulfoxide 51 mL were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. After degassing by stirring under reduced pressure in the flask, 0.098 g of copper(I) iodide (abbreviation: CuI) and 0.063 g of picolinic acid were added, and the reaction was carried out by stirring at 160 °C for 6.5 hours.

[0553] After a predetermined time had elapsed, extraction was carried out with ethyl acetate. The obtained residue was purified by silica gel column chromatography using toluene:ethyl acetate = 10:1 as the developing solvent to obtain the target product (brown solid, 2.7 g, yield 94%). The synthesis scheme of Step 5 is shown.

[0554]

Chemical formula

[0555] <Step 6: Synthesis of 1-(3,5-di-tert-butylphenyl)-3-[3-({9-[3,5-di(methyl-d 3 )-4-phenylpyridin-2-yl]carbazol-2-yl}oxy)phenyl]benzimidazolium-1,1,1-trifluoromethanesulfonate> Next, 2-[3-(benzimidazol-1-yl)phenoxy]-9-[3,5-di(methyl-d 3 )-4-phenylpyridin-2-yl]carbazole 2.7 g, (3,5-di-tert-butylphenyl)(mesityl)iodonium trifluoromethanesulfonate 5.7 g, and N,N-dimethylformamide (abbreviation: DMF) 25 mL were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. After degassing by stirring under reduced pressure in the flask, 0.13 g of copper(II) acetate (abbreviation: Cu(OAc) 2 ) was added, and the reaction was carried out by stirring at 100 °C for 6 hours.

[0556] After the predetermined time had elapsed, the solvent was distilled off, and the resulting residue was purified by silica gel column chromatography using dichloromethane:acetone = 9:1 as the developing solvent to obtain the target product (reddish-brown solid, yield 0.84 g, yield 19%). The synthesis scheme of Step 6 is shown.

[0557]

Chemical formula

[0558] <Step 7: Synthesis of (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[3,5-di(methyl-d 3 )-4-phenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz35dm4ppy-d6))> Next, 0.84 g of 1-(3,5-di-tert-butylphenyl)-3-[3-({9-[3,5-di(methyl-d 3 )-4-phenylpyridin-2-yl]carbazol-2-yl}oxy)phenyl]benzimidazolium-1,1,1-trifluoromethanesulfonate obtained in Step 6 above, 0.42 g of dichloro(1,5-cyclooctadiene)platinum(II), 0.23 g of sodium acetate, and 42 mL of N,N-dimethylformamide were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. Then, the reaction was carried out by stirring at 160 °C for 3 hours.

[0559] After the predetermined time had elapsed, the solvent was distilled off, and extraction was performed with dichloromethane. The resulting residue was purified by silica gel column chromatography using toluene as the developing solvent and then further purified by recrystallization from toluene to obtain the target product (yellow solid, yield 0.19 g, yield 22%).

[0560] 0.12 g of the obtained yellow solid was purified by sublimation using the train sublimation method. The sublimation purification conditions were heating the solid at a pressure of 2.5 Pa and 305 °C. After sublimation purification, the desired yellow solid was obtained with a yield of 0.060 g and a yield of 50%. The synthesis scheme of Step 7 is shown.

[0561] [Chemical formula]

[0562] <Properties of Organometallic Complexes> In addition, the analysis results of the yellow solid obtained in Step 7 by nuclear magnetic resonance spectroscopy ( 1 1H-NMR) are shown. From this, it was found that Pt(mmtBubOcz35dm4ppy-d6) was obtained in this synthesis example.

[0563] 1 1H-NMR. δ(CDCl 3 3): 1.08 (brs, 9H), 1.42 (brs, 9H), 6.93 - 6.94 (m, 1H), 7.10 (d, 2H), 7.19 (d, 1H), 7.29 - 7.42 (m, 7H), 7.48 - 7.53 (m, 3H), 7.58 (d, 1H), 7.71 (d, 1H), 7.77 (brs, 1H), 7.87 (d, 2H), 8.03 (d, 1H), 8.27 (d, 1H), 8.79 (s, 1H).

[0564] (Reference Example 2) ≪Synthesis Example 2≫ In this reference example, the synthesis method of the organometallic complex shown as platinum complex C in the example, (2-{3-[3-(3,5-di-tert-butylphenyl)benzimidazol-1-yl-2-ylidene-κC2]phenoxy-κC2}-9-[3,5-di(methyl-d3)-4-tert-butylphenyl-2-pyridinyl-κN]carbazole-2,1-diyl-κC)platinum(II) (abbreviation: Pt(mmtBubOcz35dm4tBuppy-d6)) is specifically exemplified.

[0565] [Chemical formula]

[0566] <Step 1: Synthesis of 4-tert-butylphenyl-2-fluoro-3,5-dimethylpyridine> First, 6.0 g of 2-fluoro-4-iodo-3,5-dimethylpyridine, 13 g of 4-tert-butylphenylboronic acid, 15 g of potassium carbonate, 96 mL of 1,4-dioxane, and 24 mL of water were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. After degassing by stirring the inside of the flask under reduced pressure, 1.8 g of tetrakis(triphenylphosphine)palladium(0) (abbreviation: Pd(PPh 3 ) 4 ) was added, and the reaction was carried out by stirring at 85 °C for 7.5 hours.

[0567] After a predetermined time had elapsed, extraction with toluene was performed. The obtained residue was purified by silica gel column chromatography using toluene as the developing solvent to obtain the target product (brown solid, yield 6.1 g, yield 100%). The synthesis scheme of Step 1 is shown.

[0568]

Chemical formula

[0569] <Step 2: Synthesis of 2-bromo-9-(4-tert-butylphenyl-3,5-dimethylpyridin-2-yl)carbazole> First, 6.1 g of 4-tert-butylphenyl-2-fluoro-3,5-dimethylpyridine, 6.1 g of 2-bromocarbazole, 15 g of cesium carbonate, and 54 mL of N-methyl-2-pyrrolidone (abbreviation: NMP) were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. Then, the reaction was carried out by stirring at 140 °C for 8 hours.

[0570] After the elapse of a predetermined time, extraction was carried out with toluene. The obtained residue was purified by silica gel column chromatography using hexane:toluene = 1:5 as the developing solvent to obtain the target product (white solid, yield 8.5 g, yield 74%). The synthetic scheme of Step 2 is shown.

[0571]

Chemical formula

[0572] <Step 3: Synthesis of 2-bromo-9-[4-tert-butylphenyl-3,5-di(methyl-d 3 )pyridin-2-yl]carbazole> Next, 8.5 g of 2-bromo-9-(4-tert-butylphenyl-3,5-dimethylpyridin-2-yl)carbazole obtained in Step 2 above, dimethyl sulfoxide-d 6 (abbreviation: DMSO-d 6 ) 25 mL and 1.0 g of sodium tert-butoxide were placed in an eggplant-shaped flask, and the inside was purged with nitrogen. Then, the reaction was carried out by stirring at 140 °C for two and a half hours.

[0573] After the elapse of a predetermined time, extraction was carried out with toluene. The obtained residue was purified by silica gel column chromatography using hexane:toluene = 1:5 as the developing solvent to obtain the target product (yellowish-white solid, yield 6.2 g, yield 72%). The synthetic scheme of Step 3 is shown.

[0574]

Chemical formula

[0575] <Step 4: Synthesis of 2-hydroxy-9-[4-tert-butylphenyl-3,5-di(methyl-d 3 )pyridin-2-yl]carbazole> Next, 2-bromo-9-[4-tert-butylphenyl-3,5-di(methyl-d obtained in Step 3 above 3) 6.2 g of [pyridin-2-yl]carbazole, 2.6 g of sodium tert-butoxide, 51 mL of dimethyl sulfoxide, and 13 mL of water were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. After degassing by stirring under reduced pressure in the flask, 0.13 g of copper(I) chloride (abbreviation: CuCl) and 0.42 g of N1,N2-bis(4-hydroxy-2,6-dimethylphenyl)oxalamide were added, and the reaction was carried out by stirring at 110 °C for 10.5 hours.

[0576] After a predetermined time had elapsed, 300 mL of water was added, and the resulting mixture was suction filtered. The obtained residue was purified by recrystallization from toluene to obtain the target product (gray solid, yield 3.8 g, yield 70%). The synthesis scheme of Step 4 is shown.

[0577]

Chemical formula

[0578] <Step 5: 2-[3-(benzimidazol-1-yl)phenoxy]-9-[4-tert-butylphenyl-3,5-di(methyl-d 3 ) Synthesis of [pyridin-2-yl]carbazole> Next, 3.8 g of 2-hydroxy-9-[4-tert-butylphenyl-3,5-di(methyl-d 3 ) [pyridin-2-yl]carbazole obtained in Step 4 above, 2.6 g of 1-(3-bromophenyl)benzimidazole, 3.7 g of tripotassium phosphate, and 88 mL of dimethyl sulfoxide were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. After degassing by stirring under reduced pressure in the flask, 0.17 g of copper(I) iodide (abbreviation: CuI) and 0.11 g of picolinic acid were added, and the reaction was carried out by stirring at 160 °C for 3 hours.

[0579] After a predetermined time had elapsed, extraction with ethyl acetate was carried out. The obtained residue was purified by silica gel column chromatography using toluene:ethyl acetate = 10:1 as the developing solvent to obtain the target product (brown solid, yield 5.6 g, yield 100%). The synthesis scheme of Step 5 is shown in the following formula.

[0580]

Chem.

[0581] <Step 6: Synthesis of 1-(3,5-Di-tert-butylphenyl)-3-[3-({9-[4-tert-butylphenyl-3,5-di(methyl-d 3 )pyridin-2-yl]carbazol-2-yl}oxy)phenyl]benzimidazolium-1,1,1-trifluoromethanesulfonate> Next, 5.6 g of 2-[3-(benzimidazol-1-yl)phenoxy]-9-[4-tert-butylphenyl-3,5-di(methyl-d 3 )pyridin-2-yl]carbazole obtained in Step 5 above and 25 mL of N,N-dimethylformamide (abbreviation: DMF) were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. After degassing by stirring under reduced pressure inside the flask, 0.25 g of copper(II) acetate (abbreviation: Cu(OAc) 2 ) was added, and the mixture was heated at 100 °C. A solution prepared by dissolving 10 g of (3,5-di-tert-butylphenyl)(mesityl)iodonium trifluoromethanesulfonate in 100 mL of DMF was added dropwise thereto, and the reaction was carried out by stirring at 100 °C for 3 hours.

[0582] After a predetermined time had elapsed, the solvent was distilled off, and the resulting residue was purified by silica gel column chromatography using dichloromethane:acetone = 9:1 as the developing solvent to obtain the target product (brown solid, yield 8.0 g, yield 92%). The synthesis scheme of Step 6 is shown.

[0583]

Chem.

[0584] <Step 7: Synthesis of Pt(mmtBubOcz35dm4tBuppy-d 6 )> Next, 8.0 g of 1-(3,5-di-tert-butylphenyl)-3-[3-({9-[4-tert-butylphenyl-3,5-di(methyl-d 3 )pyridin-2-yl]carbazol-2-yl}oxy)phenyl]benzimidazolium-1,1,1-trifluoromethanesulfonate, 3.7 g of dichloro(1,5-cyclooctadiene)platinum(II), 2.1 g of sodium acetate, and 380 mL of DMF were placed in a three-necked flask equipped with a reflux tube, and the inside was purged with nitrogen. Then, the reaction was carried out by stirring at 160 °C for 2 hours.

[0585] After a predetermined time had elapsed, the solvent was distilled off, and extraction was performed with dichloromethane. The obtained residue was purified by silica gel column chromatography using toluene as the developing solvent, and then purified by recrystallization from a mixed solvent of toluene and ethanol to obtain the target product (yellow solid, yield 3.0 g, yield 36%).

[0586] 1.9 g of the obtained yellow solid was purified by sublimation using the train sublimation method. The sublimation purification conditions were heating the solid at a pressure of 3.1 Pa and 325 °C. After sublimation purification, the yellow solid of the target product was obtained in a yield of 1.4 g and a yield of 74%. The synthesis scheme of Step 7 is shown.

[0587]

Chemical formula

[0588] <Properties of the organometallic complex> In addition, the analysis results of the yellow solid obtained in Step 7 by nuclear magnetic resonance spectroscopy ( 1 1H-NMR) are shown below. From this, it was found that Pt(mmtBubOcz35dm4tBuppy-d6) was obtained in this synthesis example.

[0589] 1 1H-NMR.δ(CD 2 Cl 2): 1.08 (brs, 9H), 1.33 (s, 9H), 1.42 (brs, 9H), 6.86 (d, 1H), 7.03 (d, 1H), 7.10 (d, 1H), 7.20 (d, 1H), 7.29 - 7.42 (m, 6H), 7.48 (s, 1H), 7.51 (t, 2H), 7.58 (d, 1H), 7.70 (d, 1H), 7.78 (brs, 1H), 7.84 (d, 2H), 8.03 (d, 1H), 8.27 (d, 1H), 8.77 (s, 1H).

Explanation of symbols

[0590] 100A display device 100B display device 100C display device 100D display device 100E display device 100 display device 101 First electrode 101B First electrode 101G First electrode 101R First electrode 101W First electrode 102 Second electrode 103B Organic compound layer 103Bf Organic compound film 103G Organic compound layer 103Gf Organic compound film 103R Organic compound layer 103Rf Organic compound film 103 Organic compound layer 104 Common layer 110B Sub - pixel 110G Sub - pixel 110R Sub - pixel 110W Sub - pixel 110 Sub - pixel 111 Hole injection layer 112B Conductive layer 112R Conductive layer 112 Hole transport layer 113 Light - emitting layer 114 Electron transport layer 115 Electron injection layer 116 Charge generation layer 117 P-type layer 118 Electron relay layer 119 Electron injection buffer layer 120 Substrate 122 Resin layer 125f Inorganic insulating film 125 Inorganic insulating layer 126B Conductive layer 126R Conductive layer 127a Insulating layer 127f Insulating film 127 Insulating layer 128 Layer 129B Conductive layer 129R Conductive layer 130B Light-emitting device 130G Light-emitting device 130R Light-emitting device 130W Light-emitting device 130 Light-emitting device 131 Protective layer 132B Coloring layer 132G Coloring layer 132R Coloring layer 140 Connection part 141 Region 142 Adhesive layer 151B Conductive layer 151C Conductive layer 151f Conductive film 151G Conductive layer 151R Conductive layer 151 Conductive layer 152B Conductive layer 152C Conductive layer 152f Conductive film 152G Conductive layer 152R Conductive layer 152 Conductive layer 153 Insulating layer 155 Common electrode 156B Insulating layer 156C Insulating layer 156f Insulating film 156G Insulating layer 156R Insulating layer 156 Insulating layer 157 Light-shielding layer 158B Sacrificial layer 158Bf Sacrificial film 158G Sacrificial layer 158Gf Sacrificial film 158R Sacrificial layer 158Rf Sacrificial film 159B Mask layer 159Bf Mask film 159G Mask layer 159Gf Mask film 159R Mask layer 159Rf Mask film 166 Conductive layer 171 Insulating layer 172 Conductive layer 173 Insulating layer 174 Insulating layer 175 Insulating layer 176 Plug 177 Pixel section 178 Pixel 178a Pixel 178b Pixel 179 Conductive layer 190B Resist mask 190G Resist mask 190R Resist mask 191 Resist mask 201 Transistor 204 Connection part 205 Transistor 211 Insulating layer 213 Insulating layer 214 Insulating layer 215 Insulating layer 221 Conductive layer 222a Conductive layer 222b Conductive layer 223 Conductive layer 224B Conductive layer 224C Conductive layer 224G Conductive layer 224R Conductive layer 231 Semiconductor layer 240 Capacitor 241 Conductive layer 242 Connection layer 243 Insulation layer 245 Conductive layer 254 Insulation layer 255 Insulation layer 256 Plug 261 Insulation layer 271 Plug 280 Display module 281 Display section 282 Circuit section 283a Pixel circuit 283 Pixel circuit section 284a Pixel 284 Pixel section 285 Terminal section 286 Wiring section 290 FPC 291 Substrate 292 Substrate 301 Substrate 310 Transistor 311 Conductive layer 312 Low-resistance region 313 Insulation layer 314 Insulation layer 315 Element isolation layer 317 Light-shielding layer 351 Substrate 352 Substrate 353 FPC 354 IC 355 Wiring 356 Circuit 501 First electrode 502 Second electrode 511 First light-emitting unit 512 Second light-emitting unit 513 Charge generation layer 601 Source line drive circuit, drive circuit section 602 Pixel section 603 Gate line drive circuit 604 Sealing substrate 605 Sealing material 607 Space 608 Wiring for routing 610 Element substrate FET for switching FET for current control First electrode Insulator Organic compound layer Second electrode Light-emitting device FET Electronic device 700A Electronic device 700B Housing Mounting part Earphone part Earphone Display panel Optical member Display area Frame Nose pad Electronic device 800A Electronic device 800B Display unit Housing Communication unit Mounting part Control unit Imaging unit Earphone part Lens Insulating layer Electronic device 6500 Housing Display unit Power button Button Speaker Microphone Camera Light source Protection member Display panel Optical member Touch sensor panel FPC IC Printed circuit board 6518 Battery 7000 Display unit 7100 Television device 7151 Remote control operation unit 7171 Housing 7173 Stand 7200 Notebook personal computer 7211 Housing 7212 Keyboard 7213 Pointing device 7214 External connection port 7300 Digital signage 7301 Housing 7303 Speaker 7311 Information terminal 7400 Digital signage 7401 Column 7411 Information terminal 9000 Housing 9001 Display unit 9002 Camera 9003 Speaker 9005 Operation key 9006 Connection terminal 9007 Sensor 9008 Microphone 9050 Icon 9051 Information 9052 Information 9053 Information 9054 Information 9055 Hinge 9171 Portable information terminal 9172 Portable information terminal 9173 Tablet terminal 9200 Portable information terminal 9201 Portable information terminal

Claims

1. A material for a light emitting device comprising an organic compound, A vector A connecting the two most distant atoms in the lowest excited state of the organic compound; A material for a light-emitting device, in which the inner product with vector B, which is a transition dipole moment related to the light emission of the organic compound, is 2.5 or more. (The length of vector A is nm, the magnitude of vector B is debye, and the direction of vector A is determined so that the angle with vector B is 90° or less.)

2. A material for a light emitting device comprising an organometallic complex, A vector A connecting the two most distant atoms in the lowest triplet excited state of the organometallic complex; A material for a light-emitting device, in which the inner product with vector B, which is a transition dipole moment related to the light emission of the organometallic complex, is 2.5 or more. (Here, the length of vector A is nm, the magnitude of vector B is debye, and the direction of vector A is determined so that the angle with vector B is 90° or less.)

3. In claim 2, The material for a light-emitting device, wherein the organometallic complex is a tetradentate complex.

4. In claim 2, The material for a light-emitting device, wherein the organometallic complex is a cyclometallic complex.

5. In claim 2, A metal contained in the organometallic complex; A material for a light-emitting device, in which a six-membered ring is formed together with some of the atoms contained in the ligand contained in the organometallic complex.

6. In claim 2, A metal contained in the organometallic complex; A material for a light-emitting device, in which a five-membered ring is formed together with some of the atoms contained in the ligand contained in the organometallic complex.

7. In claim 6, A material for a light emitting device comprising a plurality of the five-membered rings.

8. In claim 2, A material for a light-emitting device, wherein a ligand in the organometallic complex contains carbazole.

9. In claim 2, The material for a light emitting device, wherein the metal contained in the organometallic complex is platinum.

10. In claim 2, The organometallic complex has a light emitting quantum yield of 0.60 or more.

11. In claim 2, A material for a light emitting device, in which the molecular orientation parameter a of light emitted from a light emitting device containing the above organometallic complex as a luminescent center substance in a light emitting layer is 0.23 or less.

12. A light-emitting device using the material for a light-emitting device according to any one of claims 1 to 11.

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