Light-emitting element

Abstract

To provide a light-emitting element with high luminous efficiency and that can be driven at a low voltage. [Solution] A light-emitting element having a guest material and a host material. The LUMO of the guest material The level is higher than the LUMO level of the host material, and the HOMO level of the guest material is higher than that of the host material. It is lower than the HOMO level. The guest material can convert triplet excitation energy into luminescence. It has the ability to perform the following functions: The host material has singlet excitation energy levels and triplet excitation energy levels. The difference with the level is greater than 0 eV and less than or equal to 0.2 eV, and the LUMO level of the host material and HO The energy difference with the MO level is greater than the energy of the luminescence exhibited by the guest material.

Description

[Technical Field]

[0001] One aspect of the present invention relates to a light-emitting element, or a display device having the light-emitting element, an electronic device, and a light Regarding lighting equipment.

[0002] Furthermore, one aspect of the present invention is not limited to the above-mentioned technical field. One aspect of the technical field relates to a product, method, or method of manufacture. Or, one aspect of the present invention. This refers to a process, machine, manufacture, or composition. Regarding the ter. Therefore, the technical aspects of one aspect of the present invention disclosed more specifically herein Examples include semiconductor devices, display devices, liquid crystal display devices, light-emitting devices, lighting devices, energy storage devices, and memory devices. Examples include devices, methods for driving them, or methods for manufacturing them. . [Background technology]

[0003] In recent years, electroluminescence (EL) Research and development of light-emitting devices using this technology are actively underway. The basic configuration of these light-emitting devices is The device has a configuration in which a layer containing a light-emitting material (EL layer) is sandwiched between a pair of electrodes. By applying a voltage between them, light emission can be obtained from the light-emitting material.

[0004] Since the aforementioned light-emitting element is self-illuminating, the display device using it offers excellent visibility and battery life. It has advantages such as not requiring crystalline materials and consuming less power. Furthermore, it can be manufactured to be thin and lightweight. It also has advantages such as a high response speed.

[0005] An organic material is used as the light-emitting material, and an EL layer containing the light-emitting material is provided between a pair of electrodes. In the case of a light-emitting element (for example, an organic EL element), by applying a voltage between a pair of electrodes... Electrons are injected from the cathode and holes from the anode into the light-emitting EL layer, and an electric current is generated. A current flows through it. Then, the injected electrons and holes recombine to produce a luminescent organic material. This excited the material, and light emission can be obtained from the excited, luminescent organic material.

[0006] The types of excited states that organic materials can form include singlet excited states (S * ) and triplet excited state state(T * ) There are two states: fluorescence from the singlet excited state and phosphorescence from the triplet excited state. It is called [name]. Furthermore, the statistical generation ratio of these in light-emitting elements is S * :T * =1 :3. Therefore, phosphorescence is emitted from a light-emitting element that uses a fluorescent material (fluorescent material). Light-emitting devices that use phosphorescent materials can achieve higher luminescence efficiency. Therefore, using a phosphorescent material capable of converting the energy of the triplet excited state into light emission, The development of light-emitting elements has been actively pursued in recent years (see, for example, Patent Document 1).

[0007] The energy required to excite an organic material is the LUMO level and HOMO level of the organic material. Because it depends on the energy difference with the position, it roughly corresponds to the energy of the singlet excited state, but phosphorus In light-emitting devices using light-emitting organic materials, the triplet excitation energy is the energy of the light emission. It is converted into energy. Therefore, the singlet excited state and triplet excited state formed by organic materials When the energy difference is large, the energy required to excite the organic material is the energy The energy of the emission is higher than that of the organic material by an amount equivalent to the energy difference. The difference between the energy required to do this and the energy of the light emission is the driving voltage in the light-emitting element. This increase affects the element characteristics. Therefore, regarding methods to reduce the drive voltage, Development is underway (see Patent Document 2).

[0008] Furthermore, among light-emitting elements using phosphorescent materials, in particular, light-emitting elements that emit blue light... Because it is difficult to develop stable organic materials with high triplet excitation energy levels, It has not yet been put into practical use. Therefore, stable organic materials with high triplet excitation energy levels are needed. The development of materials is needed. Furthermore, a reliable phosphorescent light-emitting element exhibiting high luminescence efficiency is required. Child development is needed. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2010-182699 [Patent Document 2] Japanese Patent Publication No. 2012-212879 [Overview of the project] [Problems that the invention aims to solve]

[0010] Iridium complexes are known as phosphorescent materials that exhibit high luminescence efficiency. As an iridium complex possessing energy, iridium has a nitrogen-containing five-membered heterocyclic skeleton as a ligand. A zinc complex is known. This nitrogen-containing five-membered heterocyclic skeleton has a high triplet excitation energy. However, it has lower electron-accepting ability compared to a nitrogen-containing six-membered heterocyclic skeleton. Therefore, a nitrogen-containing five-membered complex Iridium complexes with a ring skeleton as a ligand have a high LUMO level and electron carriers are injected. It is difficult to remove. Thus, in iridium complexes that have high luminescence energy, carriers Excitation by direct recombination of A is difficult, making it challenging to induce efficient luminescence.

[0011] Therefore, in one aspect of the present invention, a light-emitting element having a phosphorescent material has high luminescence efficiency. One of the objectives is to provide a light-emitting element. Alternatively, in one aspect of the present invention, the power consumption is One of the objectives is to provide a light-emitting element with reduced emission. Alternatively, in one aspect of the present invention, One of the objectives is to provide a light-emitting element with excellent reliability. Alternatively, in one aspect of the present invention, One of the objectives is to provide a novel light-emitting element. Alternatively, in one aspect of the present invention, One objective is to provide a light-emitting device. Alternatively, in one aspect of the present invention, a novel display device One of the objectives is to provide a suitable location.

[0012] Furthermore, the description of the above problems does not preclude the existence of other problems. Also, one aspect of the present invention is not necessarily However, it is not necessary to solve all of these problems. Other issues not mentioned above should be described in the specification, etc. This is self-evident, and it is possible to extract issues other than those mentioned above from the description in the specification, etc. ru. [Means for solving the problem]

[0013] One aspect of the present invention is to efficiently excite a phosphorescent material having high luminescence energy. This is a light-emitting element that has a suitable host material.

[0014] Therefore, one aspect of the present invention is a light-emitting element having a first material and a second material. Therefore, the energy difference between the LUMO level and the HOMO level of the first material is the LU of the second material. The first material, having a triplet excitation energy greater than the energy difference between the MO level and the HOMO level, This is a light-emitting element that has the function of converting ghee into light.

[0015] Another aspect of the present invention is a light-emitting element having a first material and a second material. Therefore, the LUMO level of the first material is higher than the LUMO level of the second material, and the H of the first material The OMO level is lower than the HOMO level of the second material, and the first material has a triplet excitation energy. It is a light-emitting element that has the function of converting - into light.

[0016] Another aspect of the present invention is a light-emitting element having a first material and a second material. Therefore, the LUMO level of the first material is equivalent to the LUMO level of the second material, and the first material The HOMO level of the first material is lower than that of the second material, and the first material has triplet excitation energy This is a light-emitting element that has the function of converting energy into light.

[0017] Another aspect of the present invention is a light-emitting element having a first material and a second material. Therefore, the LUMO level of the first material is higher than the LUMO level of the second material, and the H of the first material The OMO level is equivalent to the HOMO level of the second material, and the first material has triplet excitation energy This is a light-emitting element that has the function of converting energy into light.

[0018] Another aspect of the present invention is a light-emitting element having a first material and a second material. Therefore, the energy difference between the LUMO level and the HOMO level of the first material is the LUM level of the second material. The first material has a triplet excitation energy that is greater than the energy difference between the O level and the HOMO level. - It has the function of converting into light, and the second material has singlet excitation energy levels The difference between the triplet excitation energy level and the light-emitting element is greater than 0 eV and less than or equal to 0.2 eV. That is the case.

[0019] Another aspect of the present invention is a light-emitting element having a first material and a second material. Therefore, the LUMO level of the first material is higher than the LUMO level of the second material, and the H of the first material The OMO level is lower than the HOMO level of the second material, and the first material has a triplet excitation energy. - It has the function of converting into light, and the second material has singlet excitation energy levels The difference between the triplet excitation energy level and the light-emitting element is greater than 0 eV and less than or equal to 0.2 eV. That is the case.

[0020] Another aspect of the present invention is a light-emitting element having a first material and a second material. Therefore, the LUMO level of the first material is equivalent to the LUMO level of the second material, and the first material The HOMO level of the first material is lower than that of the second material, and the first material has triplet excitation energy The second material has the ability to convert energy into light, and the singlet excitation energy The difference between the energy level and the triplet excitation energy level is greater than 0 eV and less than or equal to 0.2 eV, resulting in emission. It is an element.

[0021] Another aspect of the present invention is a light-emitting element having a first material and a second material. Therefore, the LUMO level of the first material is higher than the LUMO level of the second material, and the H of the first material The OMO level is equivalent to the HOMO level of the second material, and the first material has triplet excitation energy The second material has the ability to convert energy into light, and the singlet excitation energy The difference between the energy level and the triplet excitation energy level is greater than 0 eV and less than or equal to 0.2 eV, resulting in emission. It is an element.

[0022] Another aspect of the present invention comprises a first material, a second material, and a third material. In a light-emitting element, the energy difference between the LUMO level and the HOMO level of the third material is the second The energy difference between the LUMO level and the HOMO level of the first material is greater than that of the first material's LUM The energy difference between the O level and the HOMO level is the energy difference between the LUMO level and the HOMO level of the second material. The energy difference is greater than that, and the first material converts the triplet excitation energy into light emission. It is a light-emitting element that has the function of being able to do this.

[0023] Another aspect of the present invention comprises a first material, a second material, and a third material. A light-emitting element, wherein the LUMO level of the third material is higher than the LUMO level of the second material. The HOMO level of the third material is lower than that of the second material, and the LUM level of the first material is lower. The O level is higher than the LUMO level of the second material, and the HOMO level of the first material is higher than the LUMO level of the second material. The first material converts triplet excitation energy into light emission at a level lower than the HOMO level of the material. It is a light-emitting element that has the function of being able to do this.

[0024] Another aspect of the present invention comprises a first material, a second material, and a third material. A light-emitting element, wherein the LUMO level of the third material is higher than the LUMO level of the second material. The HOMO level of the third material is lower than that of the second material, and the LUM level of the first material is lower. The O level is equivalent to the LUMO level of the second material, and the HOMO level of the first material is equivalent to the second material. Lower than the HOMO level of the first material, the first material converts triplet excitation energy into luminescence. It is a light-emitting element that has the function of being able to do so.

[0025] Another aspect of the present invention comprises a first material, a second material, and a third material. A light-emitting element, wherein the LUMO level of the third material is higher than the LUMO level of the second material. The HOMO level of the third material is lower than that of the second material, and the LUM level of the first material is lower. The O level is higher than the LUMO level of the second material, and the HOMO level of the first material is higher than the LUMO level of the second material. The first material is equivalent to the HOMO level of the material and converts the triplet excitation energy into light emission. It is a light-emitting element that has the function of being able to do so.

[0026] Another aspect of the present invention comprises a first material, a second material, and a third material. In a light-emitting element, the energy difference between the LUMO level and the HOMO level of the third material is the second The energy difference between the LUMO level and the HOMO level of the first material is greater than that of the first material's LUM The energy difference between the O level and the HOMO level is the energy difference between the LUMO level and the HOMO level of the second material. The energy difference is greater than that, and the first material converts the triplet excitation energy into light emission. The second material has the ability to perform the singlet excitation energy level and the triplet excitation energy level. This is a light-emitting element whose level difference is greater than 0 eV and less than or equal to 0.2 eV.

[0027] Another aspect of the present invention comprises a first material, a second material, and a third material. A light-emitting element, wherein the LUMO level of the third material is higher than the LUMO level of the second material. The HOMO level of the third material is lower than that of the second material, and the LUM level of the first material is lower. The O level is higher than the LUMO level of the second material, and the HOMO level of the first material is higher than the LUMO level of the second material. The first material converts triplet excitation energy into light emission at a level lower than the HOMO level of the material. The second material has the ability to perform the singlet excitation energy level and the triplet excitation energy level. This is a light-emitting element whose level difference is greater than 0 eV and less than or equal to 0.2 eV.

[0028] Another aspect of the present invention comprises a first material, a second material, and a third material. A light-emitting element, wherein the LUMO level of the third material is higher than the LUMO level of the second material. The HOMO level of the third material is lower than that of the second material, and the LUM level of the first material is lower. The O level is equivalent to the LUMO level of the second material, and the HOMO level of the first material is equivalent to the second material. Lower than the HOMO level of the first material, the first material converts triplet excitation energy into luminescence. The second material has the ability to perform singlet excitation energy levels and triplet excitation energy levels. This is a light-emitting element whose difference from the Ghee level is greater than 0 eV and less than or equal to 0.2 eV.

[0029] Another aspect of the present invention comprises a first material, a second material, and a third material. A light-emitting element, wherein the LUMO level of the third material is higher than the LUMO level of the second material. The HOMO level of the third material is lower than that of the second material, and the LUM level of the first material is lower. The O level is higher than the LUMO level of the second material, and the HOMO level of the first material is higher than the LUMO level of the second material. The first material is equivalent to the HOMO level of the material and converts the triplet excitation energy into light emission. The second material has the ability to perform singlet excitation energy levels and triplet excitation energy levels. This is a light-emitting element whose difference from the Ghee level is greater than 0 eV and less than or equal to 0.2 eV.

[0030] Furthermore, in each of the above configurations, the energy between the LUMO level and the HOMO level of the second material The difference is greater than or equal to the transition energy calculated from the absorption edge in the absorption spectrum of the first material. It is preferable to have it. Also, the energy difference between the LUMO level and the HOMO level of the first material is From the transition energy calculated from the absorption edge in the absorption spectrum of the first material, 0.4 A value greater than or equal to eV is preferable.

[0031] Furthermore, in each of the above configurations, the energy between the LUMO level and the HOMO level of the second material The difference is preferably greater than or equal to the energy of the light emitted by the first material. The energy difference between the LUMO level and the HOMO level is the energy of the emission exhibited by the first material. A value at least 0.4 eV greater is preferable.

[0032] Furthermore, in each of the above configurations, the second material has the function of exhibiting thermally activated delayed fluorescence at room temperature. That would be preferable.

[0033] Furthermore, in each of the above configurations, the second material has the function of supplying excitation energy to the first material. It is preferable that it has the following properties. Furthermore, the emission spectrum exhibited by the second material is the same as the absorption spectrum of the first material. It is preferable that the region overlaps with the absorption band on the longest wavelength side of the vector.

[0034] Furthermore, in each of the above configurations, the first material preferably contains iridium. It is preferable that material 1 exhibits luminescence.

[0035] Furthermore, in each of the above configurations, the second material has the function of transporting electrons. The second material preferably has the function of being able to transport holes. The first material has a π-electron-deficient heteroaromatic ring skeleton, and the second material has a π-electron-rich heteroaromatic ring skeleton. It is preferable that it has at least one of the aromatic amine skeletons.

[0036] Furthermore, in the above configuration, the π-electron-deficient hetero-aromatic ring skeleton is a diazine skeleton or tria Having at least one of the din skeleton, the π-electron-rich heteroaromatic ring skeleton is an acridine skeleton, f Phenoxazine skeleton, phenothiazine skeleton, furan skeleton, thiophene skeleton, and pyrrole skeleton It is preferable to have one or more selected from the following categories. Also, a pyrrole skeleton. This includes an indole skeleton, a carbazole skeleton, or 3-(9-phenyl-9H-carbazole It is preferable that it has a ru-3-yl)-9H-carbazole skeleton.

[0037] Another aspect of the present invention involves the light-emitting element of each of the above configurations and a color filter or transistor. A display device having at least one of the ZISTA. Another aspect of the present invention is the The electronic device comprises a display device and at least one of a housing or a touch sensor. Furthermore, another aspect of the present invention relates to the light-emitting element of each of the above configurations and a housing or touch sensor. It is a lighting device having at least one of the following. Another aspect of the present invention is a lighting device having a light-emitting element. This includes not only optical devices but also electronic devices that have light-emitting devices. A light-emitting device refers to an image display device or a light source (including lighting devices). A connector for the optical device, for example, an FPC (Flexible Printed Circuit) t) A module with a TCP (Tape Carrier Package) attached. A module with a printed circuit board located beyond the TCP, or a light-emitting element with COG (C Modules with ICs (integrated circuits) directly mounted using the hip-on-glass (HIP-ON-Glass) method are also available. It may include a light-emitting device. [Effects of the Invention]

[0038] According to one aspect of the present invention, a light-emitting element having a phosphorescent material has high luminescence efficiency. This can provide a light-emitting element with reduced power consumption according to one aspect of the present invention. It can provide a child. Or, according to one aspect of the present invention, a highly reliable light-emitting element can be provided. It can be provided. Or, according to one aspect of the present invention, a novel light-emitting element can be provided. This is possible. Alternatively, according to one aspect of the present invention, a novel light-emitting device can be provided. Alternatively, according to one aspect of the present invention, a novel display device can be provided.

[0039] Furthermore, the description of these effects does not preclude the existence of other effects. One aspect of the present invention is: It is not necessarily required to have all of these effects. Other effects are described in the specification. This is obvious from the descriptions in the specifications, drawings, and claims, and the descriptions in the specifications, drawings, and claims Therefore, it is possible to extract effects other than those mentioned above. [Brief explanation of the drawing]

[0040] [Figure 1] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention. [Figure 2] A diagram illustrating the correlation of energy levels and the correlation of energy bands in the light-emitting layer of a light-emitting element according to one embodiment of the present invention. [Figure 3] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention. [Figure 4] A diagram illustrating the correlation of energy levels and the correlation of energy bands in the light-emitting layer of a light-emitting element according to one embodiment of the present invention. [Figure 5] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention, and a diagram illustrating the correlation of energy levels. [Figure 6] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention. [Figure 7] A schematic cross-sectional view of a light-emitting element according to one embodiment of the present invention. [Figure 8] A schematic cross-sectional diagram illustrating a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 9] A schematic cross-sectional diagram illustrating a method for manufacturing a light-emitting element according to one embodiment of the present invention. [Figure 10] A top view and a schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 11] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 12] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 13] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 14] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 15] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 16] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 17] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 18] A schematic cross-sectional view illustrating a display device according to one embodiment of the present invention. [Figure 19] A block diagram and a circuit diagram illustrating a display device according to one embodiment of the present invention. [Figure 20] A circuit diagram illustrating the pixel circuit of a display device according to one embodiment of the present invention. [Figure 21] A circuit diagram illustrating the pixel circuit of a display device according to one embodiment of the present invention. [Figure 22] A perspective view showing an example of a touch panel according to one aspect of the present invention. [Figure 23] A cross-sectional view showing an example of a display device and a touch sensor according to one embodiment of the present invention. [Figure 24] A cross-sectional view showing an example of a touch panel according to one aspect of the present invention. [Figure 25] A block diagram and timing chart diagram of a touch sensor according to one aspect of the present invention. [Figure 26] Circuit diagram of a touch sensor according to one aspect of the present invention. [Figure 27]A perspective view illustrating a display module according to one embodiment of the present invention. [Figure 28] A diagram illustrating an electronic device according to one embodiment of the present invention. [Figure 29] A diagram illustrating an electronic device according to one embodiment of the present invention. [Figure 30] A diagram illustrating an electronic device according to one embodiment of the present invention. [Figure 31] A perspective view illustrating a display device according to one embodiment of the present invention. [Figure 32] A perspective view and a cross-sectional view illustrating a light-emitting device according to one embodiment of the present invention. [Figure 33] A cross-sectional view illustrating a light-emitting device according to one embodiment of the present invention. [Figure 34] A diagram illustrating a lighting device and electronic equipment according to one embodiment of the present invention. [Figure 35] A diagram illustrating a lighting device according to one embodiment of the present invention. [Figure 36] A schematic cross-sectional view illustrating a light-emitting element according to an embodiment. [Figure 37] A diagram illustrating the current efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 38] A diagram illustrating the brightness-voltage characteristics of a light-emitting element according to an embodiment. [Figure 39] A diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 40] A diagram illustrating the power efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 41] A diagram illustrating the electroluminescence spectrum of a light-emitting element according to an embodiment. [Figure 42] A diagram illustrating the emission spectrum of the host material in the example. [Figure 43] A diagram illustrating the transient fluorescence characteristics of the host material in the example. [Figure 44] A diagram illustrating the current efficiency-luminance characteristics of a comparative light-emitting element according to an embodiment. [Figure 45] A diagram illustrating the brightness-voltage characteristics of a comparative light-emitting element according to an example. [Figure 46]A diagram illustrating the external quantum efficiency-luminance characteristics of a comparative light-emitting device according to an example. [Figure 47] A diagram illustrating the power efficiency-luminance characteristics of a comparative light-emitting element according to an example. [Figure 48] A diagram illustrating the electroluminescence spectrum of a comparative light-emitting element according to the example. [Figure 49] A diagram illustrating the absorption and emission spectra of the guest material in the example. [Figure 50] A diagram illustrating the current efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 51] A diagram illustrating the brightness-voltage characteristics of a light-emitting element according to an embodiment. [Figure 52] A diagram illustrating the external quantum efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 53] A diagram illustrating the power efficiency-luminance characteristics of a light-emitting element according to an embodiment. [Figure 54] A diagram illustrating the electroluminescence spectrum of a light-emitting element according to an embodiment. [Figure 55] A diagram illustrating the emission spectrum of the host material in the example. [Figure 56] A diagram illustrating the absorption spectrum of the guest material in the example. [Figure 57] A diagram illustrating the absorption spectrum of the guest material in the example. [Modes for carrying out the invention]

[0041] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is as follows The description is not limited to the present invention, and the form and details may not depart from the spirit and scope of the present invention. It is possible to change this in various ways. Therefore, the present invention can be described in the embodiments shown below. It is not interpreted as being limited to volume.

[0042] For the sake of ease of understanding, the position, size, and scope of each component shown in the drawings, etc., are as follows: The actual location, size, and range may not be represented. Therefore, the disclosed invention may not reflect the actual location, size, or range. It is not necessarily limited to the location, size, or scope disclosed in drawings, etc.

[0043] Furthermore, in this specification, the ordinal numbers used as "1st," "2nd," etc., are used for convenience. The order of processes or stacking may not be indicated. For example, "the first" may be written as "the second" or This can be replaced with "third," etc., as appropriate in the explanation. The ordinal numbers used to specify one aspect of this invention may not be the same. be.

[0044] Furthermore, in this specification and other documents, when describing the structure of the invention using drawings, the same thing is used The symbols used may be consistent across different drawings.

[0045] Furthermore, in this specification, the terms "membrane" and "layer" are interchangeable. It is possible to change the term. For example, the term "conductive layer" can be changed to the term "conductive film." It may be possible to change it. Or, for example, change the term "insulating film" to "insulating layer". In some cases, it may be possible to change the terminology to this.

[0046] In this specification, etc., the singlet excited state (S * ) is a single with excitation energy It refers to a singlet state. Furthermore, the S1 level is the lowest singlet excitation energy level. This refers to the lowest excitation energy level of the singlet excited state. Also, the triplet excited state. (T * ) is a triplet state that has excitation energy. Also, the T1 level is a triplet state. This is the lowest level of the term excitation energy levels, and the excitation energy of the lowest triplet excited state. This refers to an energy level. In this specification, the terms singlet excited state and singlet excited energy level are used interchangeably. Even when referred to as energy levels, they represent the lowest singlet excited states and S1 levels. There are cases where this is the case. Also, when referred to as triplet excited state and triplet excited energy level, However, it may represent the lowest triplet excited state and T1 level.

[0047] Furthermore, in this specification, a fluorescent material is defined as a material that relaxes from a singlet excited state to a ground state. It is a material that emits light in the visible light region. On the other hand, phosphorescent materials are materials that emit light from a triplet excited state to a ground state. It is a material that emits light in the visible light region at room temperature when it relaxes to a certain state. In other words, phosphorus Optical materials are materials that can convert triplet excitation energy into visible light.

[0048] Furthermore, the phosphorescence emission energy or triplet excitation energy is the shortest wavelength side of the phosphorescence emission. It can be derived from the emission peak (including the shoulder) or the rising wavelength. Oh, this phosphorescence emission is time-resolved photoluminescence in a low-temperature environment (e.g., 10K). It can be observed by performing the spectroscopy method. Furthermore, the emission energy of thermally activated delayed fluorescence is , the shortest wavelength emission peak (including the shoulder) or rise time of thermally activated delayed fluorescence It can be derived from the wavelength.

[0049] In this specification, room temperature refers to any temperature between 0°C and 40°C.

[0050] Furthermore, in this specification, the blue wavelength region refers to waves between 400 nm and 505 nm. It is a long region, and blue emission means that there is at least one emission spectral peak in that region. It emits light. The green wavelength region is a wavelength region of 505 nm or more and less than 580 nm, and green light emission is light emission having at least one emission spectrum peak in this region. That is, green light emission is light emission having at least one emission spectrum peak in this region. The red wavelength region is a wavelength region of 580 nm or more and 680 nm or less, and red light emission is light emission having at least one emission spectrum peak in this region. That is, red light emission is light emission having at least one emission spectrum peak in this region.

[0051] (Embodiment 1) In this embodiment, a light-emitting element according to one aspect of the present invention will be described below with reference to FIGS. 1 to 4. Explanation.

[0052] <Configuration Example 1 of Light-Emitting Element> First, the configuration of a light-emitting element according to one aspect of the present invention will be described below with reference to FIGS. 1(A) and (B). Explanation.

[0053] FIG. 1(A) is a cross-sectional schematic view of a light-emitting element 150 according to one aspect of the present invention.

[0054] The light-emitting element 150 has a pair of electrodes (electrode 101 and electrode 102), and has an EL layer 100 provided between the pair of electrodes. The EL layer 100 has at least a light-emitting layer 130. That is. End.

[0055] In addition, the EL layer 100 shown in FIG. 1(A) has functional layers such as a hole injection layer 111, a hole transport layer 112, an electron transport layer 118, and an electron injection layer 119 in addition to the light-emitting layer 130. That is. In addition to the light-emitting layer 130, the EL layer 100 shown in FIG. 1(A) has functional layers such as a hole injection layer 111, a hole transport layer 112, an electron transport layer 118, and an electron injection layer 119.

[0056] In this embodiment, among the pair of electrodes, electrode 101 is described as the anode and electrode 102 is described as the cathode, but the configuration of the light-emitting element 150 is not limited to this. That is. 02 is described as the cathode, but this is not the case for the configuration of the light-emitting element 150. That is. That is, electrode 1 is used as the cathode and electrode 102 is used as the anode, and the lamination of each layer between the electrodes is in the reverse order. It may also be arranged in this order. That is, from the anode side, a hole injection layer 111, a hole transport layer 112, and The order in which the optical layer 130, electron transport layer 118, and electron injection layer 119 are stacked should be as follows. .

[0057] Note that the configuration of the EL layer 100 is not limited to the configuration shown in Figure 1(A), and the hole injection layer 111 At least one of the hole transport layer 112, electron transport layer 118, and electron injection layer 119 selected It is sufficient to have a configuration that has one of either. Alternatively, the EL layer 100 can be a hole or electron injection To reduce barriers, improve hole or electron transport, or inhibit hole or electron transport. It has a functional layer that has functions such as being able to suppress the quenching phenomenon caused by electrodes. It may also be configured as follows. Note that even if each functional layer is a single layer, a configuration in which multiple layers are stacked may also be possible. It may be possible.

[0058] Figure 1(B) is a schematic cross-sectional view showing an example of the light-emitting layer 130 shown in Figure 1(A). The light-emitting layer 130 shown in B) comprises at least a guest material 131 and a host material 132. The guest material 131 has the function of converting triplet excitation energy into light emission. The first material is preferably the host material 132 being the second material.

[0059] Furthermore, in the light-emitting layer 130, the host material 132 is present in the largest amount by weight, and the guest material 131 is dispersed in the host material 132.

[0060] Furthermore, as the guest material 131, any luminescent organic material may be used. The material is preferably one that has the function of converting triplet excitation energy into light emission. Furthermore, it is preferable that the material is capable of emitting phosphorescence (hereinafter also referred to as a phosphorescent material). In the following description, a configuration using a phosphorescent material as the guest material 131 will be described. Therefore, the guest material 131 may be read as a phosphorescent material.

[0061] <Light emission mechanism 1 of the light emitting element> Next, the light emission mechanism of the light emitting layer 130 will be described below.

[0062] In the light emitting element 150 according to one aspect of the present invention, by applying a voltage between a pair of electrodes (electrode 101 and electrode 102 ), electrons are injected from the cathode and holes are injected from the anode into the EL layer 100, respectively, and a current flows. Then, the injected electrons and holes recombine, and the guest material 131 in the light emitting layer 130 included in the EL layer 100 is excited, and light emission can be obtained from the excited guest material 131.

[0063] Note that light emission from the guest material 131 is obtained through the following two processes. ·(α) Direct recombination process ·(β) Energy transfer process

[0064] ≪(α) Direct recombination process≫ First, the direct recombination process in the guest material 131 will be described. Carriers (electrons and holes) recombine in the guest material 131, and an excited state of the guest material 131 is formed. In this case, the energy required to excite the guest material 131 by the direct recombination process of the carriers is the lowest unoccupied molecular orbital (also referred to as LUMO) level and the highest occupied molecular orbital (Hi ghest Occupied Molecular Orbital, also referred to as HOMO) of the guest material 131. (u) This corresponds to the energy difference with the level, and is roughly equivalent to the energy of the singlet excited state. Since guest material 131 is a phosphorescent material, the energy of the triplet excited state is converted into light emission. Therefore, the singlet excited state and triplet excited state formed by the guest material 131 are used. When the energy difference is large, the energy required to excite the guest material 131 is the energy The energy difference will result in an energy level higher than the energy of the emitted light.

[0065] The energy required to excite guest material 131 and the energy of emission The difference in drive voltage affects the characteristics of the light-emitting element. Therefore, ( α) In the direct recombination process, the emission start voltage of the light-emitting element is in the guest material 131. The voltage becomes higher than the voltage corresponding to the energy of the light emission.

[0066] Furthermore, if the guest material 131 has a high luminescence energy, the LU of the guest material 131 As the MO level rises, it becomes more difficult for the carrier electrons to be injected into the guest material 131. Direct recombination of carriers (electrons and holes) becomes less likely in guest material 131. Therefore, it is difficult to obtain high luminous efficiency in light-emitting devices.

[0067] ≪(β) Energy Transfer Process≫ Next, to explain the energy transfer process between the host material 132 and the guest material 131, Figure 2(A) shows a schematic diagram illustrating the correlation of energy levels. The notation and symbols are as follows: • Guest (131): Guest material 131 (phosphorescent material) • Host(132): Host material 132 ·S PG: S1 level of guest material 131 (phosphorescent material) ·T PG : T1 level of guest material 131 (phosphorescent material) ·S PH : S1 level of host material 132 ·T PH : T1 level of host material 132

[0068] When carriers recombine in host material 132 and singlet and triplet excited states of host material 132 are formed, as shown by route E1 and route E2 in Fig. 2(A), both the singlet excitation energy and the triplet excitation energy of host material 132 are transferred to the T1 level (T ) of guest material 131, and guest material 131 becomes a triplet excited state. Phosphorescent emission is exhibited from guest material 131 in the triplet excited state. PG ) and guest material 131 becomes a triplet excited state. Phosphorescent emission is exhibited from guest material 131 in the triplet excited state. When carriers recombine in host material 132 and singlet and triplet excited states of host material 132 are formed, as shown by route E1 and route E2 in Fig. 2(A), both the singlet excitation energy and the triplet excitation energy of host material 132 are transferred to the T1 level (T

[0069] Note that both the S1 level (S PH ) and the T1 level (T PH ) of host material 132 are preferably higher than the T1 level (T ) of guest material 131. With such an energy level PG correlation, the generated singlet excitation energy and triplet excitation energy of host material 132 can be efficiently energy transferred from the S1 level (S ) and the T1 level (T ) of host material 132 to the T1 level (T PH ) of guest material 131. PH ) to the T1 level (T ) of guest material 131. PG ) of guest material 131.

[0070] In other words, in light-emitting layer 130, there is an excitation energy [[ID= fifty-six]] donation from host material 132 to guest material 131.

[0071] Note that when light-emitting layer 130 has materials other than host material 132 and guest material 131 In this case, the light-emitting layer 130 is at the T1 level (T) of the host material 132. PH T1 is higher than ) It is preferable to have a material that has energy levels. This will cause triplet excitation of the host material 132. Energy quenching becomes less likely, and energy transfer to guest material 131 becomes more efficient. It occurs.

[0072] Furthermore, the singlet excitation energy of the host material 132 is the T1 level (T) of the guest material 131. P G In order to reduce energy loss when moving to the host material 132, S1 Level (S PH ) and T1 level (T PH It is preferable that the energy difference between them is small.

[0073] Furthermore, as shown in the energy band diagram in Figure 2(B), the LUMO level of guest material 131 The position is higher than the LUMO level of host material 132, and also higher than the HOMO level of guest material 131. The level is preferably lower than the HOMO level of the host material 132. That is, the guest material The energy difference (ΔE) between the LUMO level and the HOMO level of 131 G ) is host material 132 The energy difference (ΔE) between the LUMO level and the HOMO level. H ) is larger. Such energy By establishing an energy level relationship, an excited complex is formed between the guest material 131 and the host material 132. The reaction that occurs can be suppressed. Note that in Figure 2(B), Guest(131) represents guest material 131, Host(132) represents host material 132, and ΔE G Ha This represents the energy difference between the LUMO level and the HOMO level of material 131, and ΔE H is host This is the notation and symbol representing the energy difference between the LUMO level and the HOMO level of material 132. .

[0074] The emission exhibited by guest material 131 has a short wavelength and high emission energy. To achieve this, the energy difference (ΔE) between the LUMO level and the HOMO level of guest material 131 must be G ) is preferable to be large. On the other hand, in the light-emitting element 150, in order to reduce the driving voltage It is preferable to excite with the smallest possible excitation energy, and for that purpose, the host It is preferable that the excitation energy of the excited state formed by material 132 be small. Therefore, The energy difference (ΔE) between the LUMO level and the HOMO level of the host material 132. H ) is small That is preferable.

[0075] Furthermore, since guest material 131 is a phosphorescent light-emitting material, it emits light with triplet excitation energy. It has the ability to convert to a triplet excited state. In addition, the triplet excited state is more efficient than the singlet excited state. The energy is stable. Therefore, guest material 131 has LUMO level and HOMO level and The energy difference (ΔE G ) can emit light with lower energy. Here, The energy difference (ΔE) between the LUMO level and the HOMO level of this guest material 131 G ) but, The energy difference (ΔE) between the LUMO level and the HOMO level of material 132 H ) Larger than In this case as well, the luminescence energy (abbreviated as ΔE) exhibited by guest material 131 Em ) or inhale Transition energy (abbreviated as ΔE) calculated from the absorption edge in the absorption spectrum. abs ) but, Δ E HIf it is equivalent to or smaller than that, then from the excited state formed by the host material 132, This enables the transfer of excitation energy to the main material 131, and light emission is obtained from the guest material 131. The inventors have found that it is possible to do the following: ΔE of guest material 131 G However, guest materials The luminescence energy (ΔE) exhibited by 131 Em ) or from the absorption edge in the absorption spectrum The calculated transition energy (ΔE abs If it is greater than ), the guest material 131 is directly charged To excite the air, ΔE G This requires a large amount of electrical energy equivalent to that required to power the light-emitting element. The dynamic voltage increases. However, in one embodiment of the present invention, ΔE H (ΔE G (smaller than) The host material 132 is electrically excited by the electrical energy equivalent to that, and the energy from there Because the movement generates an excited state of the guest material 131, it can be performed with a low drive voltage and high efficiency. Therefore, light emission can be obtained from the guest material 131. The child is the light emission start voltage (brightness is 1 cd / m²). 2 The guest material exhibits a voltage that is higher than the given voltage. Luminous energy (ΔE Em It can be made smaller than the voltage equivalent to Δ. E G However, the luminescence energy (ΔE) exhibited by guest material 131 Em ) or absorption spectrum The transition energy (ΔE) calculated from the absorption edge at abs If it is considerably larger than ( For example, in the case where the guest material is a blue light-emitting material, one aspect of the present invention is particularly useful. Note that the energy of the light emission (ΔE Em ) is the shortest wavelength emission peak in the emission spectrum ( It can be derived from the wavelength of the maximum value (including the shoulder).

[0076] Furthermore, if guest material 131 contains heavy metals, spin-orbit interaction (electron spin angle) Interterm crossover between singlet and triplet states is facilitated by the interaction between momentum and orbital angular momentum. Therefore, the transition between the singlet ground state and the triplet excited state in guest material 131 is advanced. In some cases, this may be acceptable. That is, the singlet ground state and triplet excited state of guest material 131. This can increase the efficiency of luminescence and the probability of absorption involved in the transition between states. Therefore, The guest material 131 preferably contains a metallic element with a large spin-orbit interaction, and is particularly white. Metal group elements (ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium ( It is preferable that it contains Os, iridium (Ir), or platinum (Pt), and among them i The presence of lydium is involved in the direct transition between the singlet ground state and the triplet excited state. This is preferable because it increases the probability of success.

[0077] Here, for example, the HOMO level of guest material 131 is the HOMO level of host material 132. The material having the highest HOMO level among the materials of the light-emitting layer 130, which is above the HOMO level. The guest material 131 is the material with the lowest LUMO level, and the host material 132 is the material with the lowest LUMO level. In this case, the carriers (holes and...) injected from the pair of electrodes (electrode 101 and electrode 102) Of the electrons, those injected from the cathode are directed to the host material 132 in the light-emitting layer 130. The holes injected from the anode are easily injected into the guest material 131. Therefore, there are cases where an excited complex is formed between the guest material 131 and the host material 132. Yes. In particular, the relationship between the HOMO level of guest material 131 and the LUMO level of host material 132. As the energy difference becomes smaller than the luminescence energy of guest material 131, the guest The formation of an excited complex between material 131 and host material 132 is dominant. Therefore, the guest material 131 alone is less likely to generate an excited state, resulting in a lower luminescence efficiency of the light-emitting element. I'll have diarrhea.

[0078] Furthermore, if the LUMO level of guest material 131 is below the LUMO level of host material 132 Of the materials in the light-emitting layer 130, the material with the lowest LUMO level is the guest material. If material 131 is the host material 132 and the material having the highest HOMO level, Carriers (holes and electrons) injected from the pair of electrodes (electrode 101 and electrode 102) Of these, electrons injected from the cathode are injected into the guest material 131 in the light-emitting layer 130. Therefore, holes injected from the anode are more easily injected into the host material 132. Excited complexes may form between the guest material 131 and the host material 132. The energy difference between the LUMO level of guest material 131 and the HOMO level of host material 132. However, as it becomes smaller than the luminescence energy of guest material 131, guest material 131 The formation of an excited complex between the guest material and the host material 132 is dominant. In this case, the guest material Because material 131 alone makes it difficult to generate an excited state, the luminescence efficiency of the light-emitting element decreases. cormorant.

[0079] However, in a light-emitting element according to one aspect of the present invention, the guest material 131 and the host material Since the reaction that forms an excited complex with material 132 can be suppressed, it exhibits high luminescence efficiency. A light-emitting element can be fabricated. Furthermore, from this perspective, the guest material 131 LUMO level and LUMO level of host material 132, or HOMO level of guest material 131 The energy level and the HOMO level of the host material 132 may be equivalent, which is one aspect of the present invention. However, for the reasons stated below, the LUMO level and HOMO level of guest material 131 are The energy difference (ΔE G ) However, the energy between the LUMO level and the HOMO level of the host material 132 Energy difference (ΔE H It is preferable that it be greater than ).

[0080] In other words, as described above, the LUMO level and HOMO level of guest material 131 and The energy difference (ΔE G ) However, the energy between the LUMO level and the HOMO level of the host material 132 Energy difference (ΔE H Even if it is greater than ), it is calculated from the absorption edge of guest material 131. The transition energy (ΔE abs ) is ΔE H If it is equivalent to or smaller than, host material 13 The excitation energy is efficiently transferred from the excited state formed by 2 to the guest material 131. As a result, one of the features of this invention is that a low-voltage and highly efficient light-emitting element can be obtained. In this case, ΔE G >ΔE H ≥ΔE abs (ΔE G is ΔE H Larger, ΔE H is ΔE abs (The above) Therefore, the LUMO level and HOMO level of guest material 131 Energy difference (ΔE) G ) is the transition energy calculated from the absorption edge of guest material 131. Gee (ΔE absThe mechanism of one embodiment of the present invention is preferred when it is greater than ). Specifically, the energy difference (ΔE) between the LUMO level and the HOMO level of guest material 131. G ) is the transition energy (ΔE) calculated from the absorption edge of guest material 131. abs ) From 0 A value of 0.4eV or greater is preferable. Also, the energy of the luminescence exhibited by the guest material 131 (Δ E Em ) is ΔE abs It is equivalent to or smaller than LUMO Guest material 131 Energy difference (ΔE) between the level and the HOMO level G ) However, the luminescence exhibited by guest material 131 Energy (ΔE Em It is preferable that it is 0.4 eV or more greater than ).

[0081] Furthermore, the energy difference (ΔE) between the LUMO level and the HOMO level of the host material 132 H )teeth , the S1 level of host material 132 (S PH It is equivalent to or slightly larger than ) host material 132 S1 level (S PH ) is the T1 level (T PH ) is larger. Also, the host material 132 T1 Level (T PH ) is the T1 level (T PG ) That is all. Therefore, Δ E G >ΔE H ≥S PH >T PH ≧T PG (ΔE G is ΔE H Larger, ΔE H is S PH Below Above, S PH is T PH Larger, T PH is T PG (That's all.) Also, guest materials When the absorption related to the absorption edge in the absorption spectrum of 131 is the absorption related to the transition between the singlet ground state and the triplet excited state of the guest material 131, ΔT is an energy that is equal to or PG slightly smaller than ΔE abs . Therefore, in order for ΔE to be at least 0.4 eV G greater than ΔE abs , the energy difference between S and T G should preferably be small compared to the energy difference between ΔE abs and ΔE PH . Specifically, the energy difference between S PH and T is preferably greater than 0 eV and 0.2 eV or less, more preferably greater than 0 eV PH and 0.1 eV or less. PH .

[0082] When the energy difference between the singlet excitation energy level and the triplet excitation energy level is small, suitable materials for the host material 132 include thermally activated delayed fluorescence (TADF) materials. Thermally activated delayed fluorescence materials have a small energy difference between the singlet excitation energy level and the triplet excitation energy level and have the function of converting triplet excitation energy into singlet excitation energy by reverse intersystem crossing. Note that as the host material 132 according to one aspect of the present invention, it is not necessarily required to have a high reverse intersystem crossing efficiency from T to S , and it is not necessarily required to have a high luminescence quantum yield from S . Therefore, a wide range of materials can be selected. PH to S PH . PH

[0083] Also, by reducing the energy difference between the singlet excitation energy level and the triplet excitation energy level To achieve this, the host material 132 has a skeleton that has the function of transporting holes (hole transportability). It is preferable that it has a skeleton that has the function of transporting electrons (electron transportability). In this case, the excited state of the host material 132 provides the HOMO molecular orbital to the hole-transporting framework. It possesses an electron-transporting framework and has LUMO molecular orbitals, and therefore HOMO molecular orbitals The overlap with the LUMO molecular orbital becomes extremely small. In other words, a donor within a single molecule. - This makes it easier to form acceptor-type excited states, and singlet excitation energy levels and triplet excitations. The energy difference with the electromotive force level becomes smaller. Multiplet excitation energy level (S PH ) and triplet excitation energy level (T PH The difference between this and the favorable The value is greater than 0 eV and less than or equal to 0.2 eV.

[0084] Furthermore, molecular orbitals represent the spatial distribution of electrons within a molecule and can express the probability of finding an electron. It is possible. Molecular orbitals allow us to determine the electron configuration of a molecule (the spatial distribution and energy of electrons) in detail. It is possible to describe it in detail.

[0085] Furthermore, if the host material 132 has a strong donor-like skeleton, it is injected into the light-emitting layer 130. The holes are easily injected into the host material 132 and transported. Also, the host material 132 If the skeleton has strong acceptor properties, electrons injected into the light-emitting layer 130 will affect the host material Both holes and electrons are injected into 132 and become easier to transport. This is preferable because it makes it easier for the host material 132 to form an excited state.

[0086] Furthermore, the emission wavelength of guest material 131 becomes short wavelength, and the emission energy (ΔEEm ) is large The more you listen, the greater the energy difference (ΔE) between the LUMO level and the HOMO level of guest material 131. G ) becomes larger, and consequently, a large amount of energy is required to directly electrically excite the guest material. Energy is required. However, in one aspect of the present invention, the absorption of guest material 131 The transition energy (ΔE) calculated from the absorption edge in the absorption spectrum abs ) is ΔE H and If they are equal or smaller, ΔE G ΔE is much smaller than H Guest material Since material 131 can be excited, the power consumption of the light-emitting element can be reduced. Therefore, the transition energy calculated from the absorption edge in the absorption spectrum of guest material 131 Gee (ΔE abs ) and the energy between the LUMO level and the HOMO level of guest material 131 Difference (ΔE G The greater the energy difference between (i.e., the more blue light is emitted) In the case of guest materials, the effects of the mechanism of the present invention become particularly pronounced.

[0087] However, the transition energy calculated from the absorption edge in the absorption spectrum of guest material 131 Gee (ΔE abs As ) decreases, the energy of the luminescence exhibited by guest material 131 (ΔE Em ) also becomes smaller, so it is possible to obtain light with high energy, such as blue light. It becomes difficult to do so. That is, ΔE abs and ΔE G If the difference becomes too large This makes it difficult to obtain high-energy light, such as blue light.

[0088] From these observations, the energy difference between the LUMO level and the HOMO level of guest material 131 is... (ΔE G ) is the transition edge calculated from the absorption edge in the absorption spectrum of guest material 131. Energy (ΔE abs Preferably, it is greater than 0.4 eV or more and 0.8 eV or less. It is more preferable if it is in the range of 0.5 eV to 0.8 eV. Also, guest material 1 The energy of the light emitted by 31 (ΔE Em ) is ΔE abs Equivalent to or smaller than Therefore, the energy difference (ΔE) between the LUMO level and the HOMO level of guest material 131 is G )teeth, The energy of the luminescence exhibited by guest material 131 (ΔE Em ) From 0.4eV to 0.8eV It is preferable that it is larger in the range of V or less, and preferably larger in the range of 0.5eV to 0.8eV. It is preferable.

[0089] Furthermore, the LUMO level of guest material 131 is higher than that of host material 132. Since the HOMO level of guest material 131 is lower than the HOMO level of host material 132, Carriers (holes and electrons) injected from a pair of electrodes (electrode 101 and electrode 102) Of these, both holes injected from the anode and electrons injected from the cathode are emitted from the light-emitting layer 130 In this state, electrons and holes are easily injected into the host material 132. In order to be injected into the host material 132, the LUMO levels of the guest material 131 and the host material The difference between the LUMO level of material 132 and the LUMO level is preferably 0.05 eV or more, and more preferably The voltage is 0.1 eV or higher, and more preferably 0.2 eV or higher. Also, guest material 13 The difference between the HOMO level of 1 and the HOMO level of the host material 132 is preferably 0.05e. It is V or greater, more preferably 0.1eV or greater, and even more preferably 0.2eV or greater. That is the case.

[0090] Furthermore, the energy difference (ΔE) between the LUMO level and the HOMO level of the host material 132 H )teeth The energy difference (ΔE) between the LUMO level and the HOMO level of guest material 131. G Smaller than Therefore, the carriers (holes and electrons) injected into the light-emitting layer 130 recombine to form excitation As an initial state, the excited state formed by the host material 132 is more energetically stable. Therefore, most of the excited states generated in the light-emitting layer 130 are formed in the host material 132. It will exist as an excited state. Therefore, according to the configuration of one aspect of the present invention, This facilitates the transfer of excitation energy from the excited state of the host material 132 to the guest material 131. By doing so, the driving voltage of the light-emitting element can be reduced, and the luminous efficiency can be increased. ru.

[0091] Furthermore, based on the relationship between the LUMO level and the HOMO level described above, the relationship between guest material 131 and host In combination with material 132, the oxidation potential of guest material 131 is equal to that of host material 132. The oxidation potential of the guest material 131 is higher than that of the host material 132, and the reduction potential of the guest material 131 is higher than that of the host material 132. It is preferable that the oxidation potential is lower than the position. By having such a relationship between oxidation potential and reduction potential, Similarly, the reaction that forms an excited complex between guest material 131 and host material 132 is suppressed. It can be controlled. Note that oxidation potential and reduction potential are related to cyclic voltane. It can be measured by the metric (CV) method.

[0092] By configuring the light-emitting layer 130 as described above, the light emitted from the guest material 131 of the light-emitting layer 130 is achieved. It can be obtained efficiently.

[0093] <Energy transfer mechanism> Next, the control of the intermolecular energy transfer process between the host material 132 and the guest material 131. Let's explain the factors. The mechanism of energy transfer between molecules is the Förster mechanism (bi Two mechanisms have been proposed: the polar-dipole interaction and the Dexter mechanism (electron exchange interaction). It is being done.

[0094] ≪Förster mechanism≫ In the Förster mechanism, energy transfer does not require direct contact between molecules, and the host Energy transfer occurs through the resonance phenomenon of dipole vibrations between material 132 and guest material 131. This is due to the resonance phenomenon of dipole oscillation, which transfers energy from the host material 132 to the guest material 131. The excited host material 132 returns to the ground state, and the guest material 13 returns to the ground state. 1 becomes an excited state. Note that the rate constant k of the Förster mechanism h*→g This is shown in equation (1). .

[0095]

number

[0096] In equation (1), ν represents the frequency, and f' h (ν) is a standard for host material 132. Emission spectra (when discussing energy transfer from singlet excited states, fluorescence spectra are used) When discussing energy transfer from triplet excited states, the phosphorescent spectrum is used. ε g (ν) represents the molar extinction coefficient of guest material 131, N represents Avogadro's number, and n R represents the refractive index of the medium, and R represents the intermolecular distance between the host material 132 and the guest material 131. τ represents the measured lifetime of the excited state (fluorescence lifetime or phosphorescence lifetime), and c represents the speed of light. φ is the emission quantum yield (when discussing energy transfer from singlet excited states, this refers to the fluorescence quantum yield). The rate (or phosphorescent quantum yield when discussing energy transfer from triplet excited states) is expressed as K. 2 teeth , a coefficient representing the orientation of the transition dipole moments of the host material 132 and the guest material 131 (0 or 4) is the case. Note that in the case of random orientation, K 2 = 2 / 3

[0097] Dexter Mechanism In the Dexter mechanism, the host material 132 and the guest material 131 come into contact with each other to create an orbital overlap. Approaching within effective contact distance, electrons from the excited host material 132 and the ground state guest material 13 Energy transfer occurs through the exchange of electrons with 1. Note that the rate constant k of the Dexter mechanism. h*→g This is shown in equation (2).

[0098]

number

[0099] In equation (2), h is Planck's constant, and K is a constant with the dimension of energy. Here, ν represents the frequency, and f' h (ν) is the normalized luminescence of the host material 132. Pectol (When discussing energy transfer from singlet excited states, use fluorescence spectra, triplet When discussing energy transfer from an excited state, the phosphorescent spectrum is represented, and ε' g (ν) The normalized absorption spectrum of guest material 131 is shown, and L represents the effective molecular radius. R represents the intermolecular distance between the host material 132 and the guest material 131.

[0100] Here, the energy transfer efficiency φ from the host material 132 to the guest material 131 is shown. ET is, number It is expressed by equation (3). k r This is the luminescence process of the host material 132 (energy from singlet excited state When discussing energy transfer, use fluorescence; when discussing energy transfer from triplet excited states, use phosphorus. This represents the velocity constant of light, k n This is the non-luminescent process of the host material 132 (thermal deactivation and intersystem crossing). The rate constant is represented, and τ represents the measured lifetime of the excited state of the host material 132.

[0101]

number

[0102] From equation (3), the energy transfer efficiency φ ET In order to increase the speed of energy transfer degree constant k h*→g Increase the other competing rate constants k r +k n (=1 / τ) You'll understand that it's better if it's smaller.

[0103] ≪A concept for enhancing energy transfer≫ In energy transfer by the Förster mechanism, the energy transfer efficiency φ ET is, quantity Quantum yield φ (when discussing energy transfer from singlet excited states, use fluorescence quantum yield, triple When discussing energy transfer from excited states, a higher phosphorescence quantum yield is preferable. Emission spectrum of host material 132 (when discussing energy transfer from singlet excited state) (Fluorescence spectrum) and absorption spectrum of guest material 131 (from singlet ground state to triplet excitation) It is preferable that there is a large overlap with the absorption corresponding to the transition to the initial state. Furthermore, guest material A higher molar extinction coefficient for material 131 is also preferable. This is because the luminescence spectrum of the host material 132 The culvert and the absorption band that appears at the longest wavelength end of the absorption spectrum of guest material 131 overlap. It means that.

[0104] Furthermore, in energy transfer by the Dexter mechanism, the rate constant k h*→g Make it bigger To do this, we need to consider the emission spectrum of the host material 132 (to discuss energy transfer from the singlet excited state). When discussing the fluorescence spectrum, use the fluorescence spectrum; when discussing energy transfer from the triplet excited state, use the phosphorescence spectrum. Absorption spectra of the culvert and guest material 131 (from singlet ground state to triplet excited state) A larger overlap with the absorption corresponding to the transition is desirable. Therefore, the energy transfer efficiency The optimization involves comparing the emission spectrum of the host material 132 with the absorption spectrum of the guest material 131. This is achieved by the overlap with the absorption band that appears at the longest wavelength.

[0105] <Example of light-emitting element configuration 2> Next, regarding a light-emitting element having a configuration different from that shown in Figures 1(A) and 1(B), see Figure 3(A Using (B), the following explanation will be provided.

[0106] Figure 3(A) is a schematic cross-sectional view of a light-emitting element 152 according to one embodiment of the present invention. In the above, the same hatch pattern is used in the parts that have the same function as the symbols shown in Figure 1(A). The symbol may be omitted. Also, the same symbol is used for parts with similar functions. And sometimes, detailed explanations are omitted.

[0107] The light-emitting element 152 has a pair of electrodes (electrode 101 and electrode 102), and between the pair of electrodes It has an EL layer 100 provided therein. The EL layer 100 has at least an emissive layer 135. .

[0108] Figure 3(B) is a schematic cross-sectional view showing an example of the light-emitting layer 135 shown in Figure 3(A). The light-emitting layer 135 shown in B) comprises at least a guest material 131, a host material 132, and a host It has material 133.

[0109] Furthermore, in the light-emitting layer 135, the host material 132 or host material 133 is the most... There are many of them, and guest material 131 is dispersed among host material 132 and host material 133. Here, guest material 131 can convert triplet excitation energy into light emission. The first material has the function of being a second material, and the host material 132 is a second material, and the host material 1 It is preferable that 33 is a third material.

[0110] <Light-emitting mechanism of the light-emitting element 2> Next, the light-emitting mechanism of the light-emitting layer 135 will be explained below.

[0111] In one embodiment of the present invention, the light-emitting element 152 also has a pair of electrodes (electrode 101 and electrode 102 The holes and electrons injected from ) recombine, thereby creating the light-emitting layer of the EL layer 100. The guest material 131 within 135 becomes excited, and light is emitted from the excited guest material 131. It can be obtained.

[0112] Furthermore, light emission from guest material 131 is obtained through the following two processes. ·(α) Direct recombination process (β) Energy transfer process

[0113] Regarding the (α) direct recombination process, the direct recombination process described in the light emission mechanism of the light emission layer 130 above is explained. Since this process is similar to the recombination process, we will omit the explanation here.

[0114] ≪(β) Energy Transfer Process≫ The energy transfer process of host material 132, host material 133, and guest material 131 To illustrate this, Figure 4(A) shows a schematic diagram illustrating the correlation of energy levels. The notation and symbols in 4(A) are as follows; for other notations and symbols, see Figure This is the same as 2(A). • Host(133): Host material 133 ·S H : S1 level of host material 133 ·T H : T1 level of host material 133

[0115] The carriers recombine in the host material 132, leading to the singlet excited state of the host material 132. And when a triplet excited state is formed, as shown in routes E1 and E2 of Figure 4(A) Thus, both the singlet excitation energy and the triplet excitation energy of the host material 132 are, T1 level of guest material 131 (T PG ) moves to guest material 131 and Yes. The guest material 131, which is in a triplet excited state, exhibits phosphorescence.

[0116] Furthermore, the excitation energy is efficiently transferred from the host material 132 to the guest material 131. For this to happen, the T1 level of the host material 133 (T H ) is the T1 level (T P H It is preferable that this is higher than ). This results in the triplet excitation energy of the host material 132. Quenching is less likely to occur, and energy transfer to guest material 131 occurs more efficiently.

[0117] Furthermore, as shown in the energy band diagram in Figure 4(B), the LUMO level of guest material 131 The position is higher than the LUMO level of host material 132, and also higher than the HOMO level of guest material 131. The level is preferably lower than the HOMO level of the host material 132. That is, the guest material The energy difference (ΔE) between the LUMO level and the HOMO level of 131 G ) is host material 132 The energy difference (ΔE) between the LUMO level and the HOMO level. H ) is larger. Such energy By establishing an energy level relationship, an excited complex is formed between the guest material 131 and the host material 132. The reaction that occurs can be suppressed. Furthermore, from this perspective, the light emission mechanism of the light-emitting element As mentioned in 1, the LUMO levels of guest material 131 and the LUMO levels of host material 132 The HOMO levels of guest material 131 and host material 132 are the same. It may also be the case that, and this is one aspect of the present invention.

[0118] Furthermore, the LUMO level of host material 133 is higher than that of host material 132. Furthermore, the HOMO level of host material 133 is lower than the HOMO level of host material 132. This is preferable. That is, the energy between the LUMO level and the HOMO level of the host material 133 The Ghee difference is the energy difference (ΔE) between the LUMO level and the HOMO level of the host material 132. H ) It is greater. By creating this kind of energy level relationship, the host material 132 and the host The reaction that forms an excited complex with material 133 can be suppressed. Note that in Figure 4(B) In this context, Host(133) represents the host material 133, and other notations and symbols are as shown in Figure 2(B It is the same as ).

[0119] Furthermore, the difference between the HOMO levels of host material 132 and host material 133, and The difference between the LUMO levels of host material 132 and host material 133 is The energy is preferably 0.1 eV or more, and more preferably 0.2 eV or more. - By having a difference, the electrons injected from the pair of electrodes (electrode 101 and electrode 102) Both the carrier and the hole carrier are preferable because they are easily injected into the host material 132. be.

[0120] Furthermore, the LUMO level of host material 133 is higher than that of guest material 131. It can be either very low or very low, and the HOMO level of host material 133 is the same as the HOMO level of guest material 131. It can be higher or lower than the level.

[0121] Furthermore, the energy difference (ΔE) between the LUMO level and the HOMO level of the host material 132 H )teeth , the energy difference between the LUMO level and the HOMO level of the host material 133 is smaller than the host The energy difference (ΔE) between the LUMO level and the HOMO level of material 132 H ) is guest material 1 The energy difference (ΔE) between the LUMO level and the HOMO level of 31 G Because it is smaller than the luminescent layer The excited states formed by the recombination of carriers (holes and electrons) injected into 135 are as follows: From the excited state formed by the host material 133 or the guest material 131, the host material 132 The excited state formed by is more energetically stable. Therefore, the light generated in the light-emitting layer 135 Most of the excited states exist as excited states formed by the host material 132. Therefore, in the light-emitting layer 135 as well, similar to the configuration of the light-emitting layer 130, This facilitates the transfer of excitation energy from the excited state of the host material 132 to the guest material 131. This allows the driving voltage of the light-emitting element 152 to be reduced, thereby increasing the luminous efficiency. Cut.

[0122] Furthermore, in the host material 133, holes and electrons recombine and the host material 133 becomes excited. Even when an initial state is formed, the LUMO level and HOMO level of the host material 133 The energy difference is calculated from the energy difference between the LUMO level and the HOMO level of the host material 132. Because it is large, the excitation energy of the host material 133 is quickly transferred to the host material 132. - It can move. Subsequently, the excitation energy is used for the light emission mechanism of the light emission layer 130. Through a similar process, energy is transferred to guest material 131, Light can be obtained from this. Furthermore, holes and electrons can be regenerated in the host material 133. Considering the possibility of bonding, host material 133, like host material 132, undergoes singlet excitation. Materials with a small energy difference between the energy level and the triplet excitation energy level, especially thermally activated materials. It is preferable that the material is a delayed fluorescence material.

[0123] Furthermore, in order to efficiently obtain luminescence from the guest material 131, the S1 standard of the host material 133 is Rank (S H ) is the S1 level (S PH ) and the host material 133 T1 level (T H ) is the T1 level (T PH ) or higher is preferable.

[0124] Furthermore, based on the relationship between the LUMO level and the HOMO level described above, the host material 133 and the host In combination with material 132, the oxidation potential of host material 133 is as follows: The oxidation potential of the host material 133 is higher than that of the host material 132, and the reduction potential of the host material 133 is higher than that of the host material 132. It is preferable that the oxidation potential is lower than the position. By having such a relationship between oxidation potential and reduction potential, Similarly, the reaction that forms an excited complex between host material 133 and host material 132 is suppressed. It can be controlled.

[0125] Furthermore, the combination of host material 132 and host material 133 provides a function for transporting holes. In the case of a combination of a material that has the function of transporting electrons and a material that has the function of transporting electrons, the mixing ratio Therefore, it becomes possible to easily control the carrier balance. Specifically, transporting holes Materials with the function of transporting electrons: Materials with the function of transporting electrons = 1:9 to 9:1 (by weight) A range is preferred. Furthermore, having this configuration allows for easy control of the carrier balance. Because this is possible, the carrier recombination region can also be easily controlled.

[0126] By configuring the light-emitting layer 135 as described above, the light emitted from the guest material 131 of the light-emitting layer 135 is achieved. It can be obtained efficiently.

[0127] <Material> Next, the details of the components of a light-emitting element according to one aspect of the present invention will be described below.

[0128] ≪Luminous layer≫ In the light-emitting layer 130 and the light-emitting layer 135, the host material 132 contains at least the guest material 1 It is present in greater proportion by weight than 31, and guest material 131 (phosphorescent material) is present in host material 132. It will be distributed.

[0129] ≪Host Material 132≫ The energy difference between the S1 level and the T1 level of the host material 132 is preferably small. Physically, it is greater than 0 eV and less than or equal to 0.2 eV.

[0130] The host material 132 has a hole-transporting skeleton and an electron-transporting skeleton. It is preferable that the host material 132 has a π-electron-rich heteroaromatic ring skeleton or It is preferable that the host has an aromatic amine skeleton and a π-electron-deficient heteroaromatic ring skeleton. Because material 132 has the above-described skeleton, it creates donor-acceptor type excited states within the molecule. It becomes easier to form. Furthermore, the donor and acceptor properties coexist within the host material 132 molecule. To make it stronger, an electron-transporting skeleton and a hole-transporting skeleton are directly bonded together. It is preferable to have a structure such as a π-electron-rich heteroaromatic ring skeleton or an aromatic a It is preferable that the molecule has a structure in which the mine skeleton and the π-electron-deficient aromatic ring skeleton are directly bonded. By strengthening both the donor and acceptor properties within the host material 132, the HOMO is enhanced. The overlap between the region where molecular orbitals are distributed in LUMO and the region where molecular orbitals are distributed in LUMO. This can reduce the singlet excitation energy level and triplet excitation energy level of the host material 132. It becomes possible to reduce the energy difference with the energy level. Also, host material 132 This makes it possible to maintain the triplet excitation energy level at a high energy level.

[0131] Materials with a small energy difference between the singlet excitation energy level and the triplet excitation energy level. Examples include thermally activated delayed fluorescence materials. Note that thermally activated delayed fluorescence materials are triplet fluorescence materials. Because the difference between the excitation energy level and the singlet excitation energy level is small, reverse intersystem crossing occurs. It is a material that has the function of converting energy from a triplet excited state to a singlet excited state. Therefore, the triplet excited state can be upconverted to a singlet excited state with only a small amount of thermal energy. It allows for reverse intersystem crossing (BART) and efficiently exhibits luminescence (fluorescence) from the singlet excited state. This can be achieved. Furthermore, conditions under which thermally activated delayed fluorescence can be efficiently obtained include triplet excitation energy. The energy difference between the energy level and the singlet excitation energy level is preferably greater than 0 eV. The voltage is 0.2 eV or less, and more preferably greater than 0 eV and 0.1 eV or less. It can be done.

[0132] When a thermally activated delayed fluorescence material is composed of only one type of material, for example, the following materials can be used. It is possible.

[0133] First, there are fullerenes and their derivatives, acridine derivatives such as proflavin, and eosin. It can be produced. Also, magnesium (Mg), zinc (Zn), cadmium (Cd), tin (S) n) Metals containing platinum (Pt), indium (In), or palladium (Pd), etc. Examples include metal-containing porphyrins. For example, protoporph Fluorine-tin fluoride complex (SnF2(Proto IX)), mesoporphyrin-fluoride Tin complex (SnF2(Meso IX)), hematoporphyrin-tin fluoride complex (Sn F2 (Hemato IX), coproporphyrin tetramethyl ester - tin fluoride Complex (SnF2(Copro III-4Me)), octaethylporphyrin-fluoride Tin complex (SnF2(OEP)), Ethioporphyrin-tin fluoride complex (SnF2(E Examples include tio I)) and octaethylporphyrin-platinum chloride complex (PtCl2OEP). It can be done.

[0134] [ka]

[0135] Furthermore, as a thermally activated delayed fluorescence material composed of one type of material, a π-electron-rich complex atom is an example. Heterocyclic compounds having aromatic rings and π-electron-deficient heteroaromatic rings can also be used. Specifically is 2-(biphenyl-4-yl)-4,6-bis(12-phenylindoro[2,3- a)Carbazole-11-yl)-1,3,5-triazine (abbreviation: PIC-TRZ), 2-{4-[3-(N-phenyl-9H-carbazol-3-yl)-9H-carbazol [9-yl]phenyl]-4,6-diphenyl-1,3,5-triazine (abbreviation: PC) CzPTzn), 2-[4-(10H-phenoxazine-10-yl)phenyl]-4, 6-Diphenyl-1,3,5-triazine (abbreviation: PXZ-TRZ), 3-[4-(5- Phenyl-5,10-dihydrophenazine-10-yl)phenyl]-4,5-diphenyl Lu-1,2,4-triazole (abbreviation: PPZ-3TPT), 3-(9,9-dimethyl- 9H-acridine-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] Examples include -9,9'-anthracene]-10'-one (abbreviated as ACRSA). Because the cyclic compounds have π-electron-rich heteroaromatic rings and π-electron-deficient heteroaromatic rings, High transportability and hole transportability are desirable. In particular, a skeleton having a π-electron-deficient heteroaromatic ring is preferred. Among these, diazine skeletons (pyrimidine skeletons, pyrazine skeletons, pyridazine skeletons), or tri The azine skeleton is preferred because it is stable and reliable. Furthermore, the π-electron-rich heteroaromatic ring is also preferred. Among the skeletons it possesses, there are acridine skeletons, phenoxazine skeletons, phenothiazine skeletons, and flavone skeletons. The ¹ⁿ skeleton, thiophene skeleton, and pyrrole skeleton are stable and reliable, therefore, the said skeletons It is preferable to have one or more selected from among them. As for the dibenzofuran skeleton, as for the thiophene skeleton, the dibenzothiophene skeleton is The following are preferable. The pyrrole skeletons include the indole skeleton, the carbazole skeleton, and The 3-(9-phenyl-9H-carbazole-3-yl)-9H-carbazole skeleton is particularly noteworthy. This is preferable. Furthermore, when a π-electron-rich heteroaromatic ring and a π-electron-deficient heteroaromatic ring are directly bonded together... The substance exhibits donor properties for π-electron-rich heteroaromatic rings and acceptor properties for π-electron-deficient heteroaromatic rings. Since both are strong, the difference between the singlet excited state level and the triplet excited state level becomes small, especially preferable.

[0136] [ka]

[0137] Furthermore, as a skeleton having a π-electron-deficient heteroaromatic ring, a condensed complex having a diazine skeleton A ring skeleton is preferred because it is more stable and reliable, and among them, the benzoflopyrimidine skeleton is preferred. The benzothienopyrimidine skeleton is particularly preferred due to its high acceptor properties. An example of a lopyrimidine skeleton is the benzoflo[3,2-d]pyrimidine skeleton. Furthermore, as a benzothienopyrimidine skeleton, for example, benzothieno[3,2-d] One example is the pyrimidine skeleton.

[0138] As a skeleton having a π-electron-rich heteroaromatic ring, the bicarbazole skeleton has an excitation energy - is preferable because it is high, stable and reliable. For example, the bicarbazole skeleton is 2 Bicarbazole bone in which two carbazolyl groups are bonded to each other at any of the positions from 1 to 4. The grade is particularly preferred due to its high donor potential. For example, the bicarbazole skeleton is 2 ,2'-bi-9H-carbazole skeleton, 3,3'-bi-9H-carbazole skeleton, 4,4 '-bi-9H-carbazole skeleton, 2,3'-bi-9H-carbazole skeleton, 2,4'- Examples include the bi-9H-carbazole skeleton and the 3,4'-bi-9H-carbazole skeleton. .

[0139] Furthermore, from the perspective of widening the band gap and increasing the triplet excitation energy, The 9th position of one of the carbazolyl groups in the bicarbazole skeleton directly benzoflopyrimid Compounds bonded to a benzothienopyrimidine skeleton or a benzothienopyrimidine skeleton are preferred. The carbazole skeleton and the benzoflopyrimidine skeleton or benzothienopyrimidine skeleton When directly bonded, it results in a relatively low molecular weight compound, making it suitable for vacuum deposition (at relatively low temperatures). This structure is preferable as it allows for vacuum deposition. Generally, a lower molecular weight results in better heat resistance after film formation. Although the properties are often low, the benzoflopyrimidine skeleton, benzothienopyrimidine skeleton, Furthermore, because the bicarbazole skeleton is a rigid skeleton, compounds having this skeleton have a relative molecular weight. It is possible to have sufficient heat resistance even at a relatively low temperature. Furthermore, this structure has band gaps This is preferable because it increases the pulse level and raises the excitation energy level.

[0140] Furthermore, the bicarbazole skeleton and the benzoflopyrimidine skeleton or benzothienopyrimidine In cases where the skeleton and the arylene group are bonded via an arylene group, the number of carbon atoms in the arylene group When the number of carbon atoms is 6 to 25, preferably 6 to 13, the band gap and triplet Not only can both excitation energies be kept high, but the resulting compound has a relatively low molecular weight. Therefore, it becomes a structure suitable for vacuum deposition (vacuum deposition can be performed at relatively low temperatures).

[0141] Furthermore, the bicarbazole skeleton is directly or via the arylene group, benzofloxacin [3,2 -d] Binds to the pyrimidine skeleton or the benzothieno[3,2-d]pyrimidine skeleton, Preferably, a benzoflo[3,2-d]pyrimidine skeleton or benzothieno[3,2- [d] By binding to the 4-position of the pyrimidine skeleton, the compound exhibits excellent carrier transport properties. Therefore, a light-emitting element using this compound can be driven at a low voltage. ru.

[0142] Examples of compounds The compound according to one embodiment of the present invention described above is a compound represented by the following general formula (G0). .

[0143] [ka]

[0144] In the above general formula (G0), A is a substituted or unsubstituted benzoflopyrimidine skeleton. , or represents the benzothienopyrimidine skeleton. The benzophropyrimidine skeleton or ben If the zothienopyrimidine skeleton has substituents, such substituents may have 1 to 6 carbon atoms. Alkyl groups, cycloalkyl groups having 3 to 7 carbon atoms, or substitutions of groups having 6 to 13 carbon atoms Unsubstituted aryl groups can also be selected as substituents. C1 to C6 alkyl groups Specifically, the groups include methyl group, ethyl group, propyl group, isopropyl group, and butyl group. Examples include isobutyl groups, tert-butyl groups, and n-hexyl groups. Specifically, examples of cycloalkyl groups having 3 to 7 carbon atoms include cyclopropyl groups and cyclopropyl groups. Examples include cyclopentyl groups, cyclopentyl groups, and cyclohexyl groups. Also, the number of carbon atoms The aryl groups 6 to 13 include phenyl, naphthyl, biphenyl, and fluorenyl groups. The 'L' group can be given as a specific example.

[0145] Also, R 1 ~R 15 Each of these independently consists of hydrogen, substituted or unsubstituted carbon atoms with 1 or more carbon atoms. 6 alkyl groups, substituted or unsubstituted cycloalkyl groups having 3 to 7 carbon atoms, or substituted groups. Alternatively, it represents any of the unsubstituted aryl groups with 6 to 13 carbon atoms. Specifically, propyl groups include methyl, ethyl, propyl, isopropyl, and butyric groups. Examples include the 1xyl group, isobutyl group, tert-butyl group, and n-hexyl group. Furthermore, specific examples of cycloalkyl groups having 3 to 7 carbon atoms include cyclopropyl groups, cyclopropyl groups, and cyclopropyl groups. Examples include chlorobutyl groups, cyclopentyl groups, and cyclohexyl groups. Examples of aryl groups having 6 to 13 carbon atoms include phenyl, naphthyl, biphenyl, and flu. The olen group can be given as a specific example. Furthermore, the alkyl and cyclic groups mentioned above... The R-alkyl group and the aryl group may have substituents, and these substituents are bonded to each other. A ring may be formed. The substituent may be an alkyl group having 1 to 6 carbon atoms, or a ring having 3 carbon atoms. A cycloalkyl group with up to 7 carbon atoms, or an aryl group with 6 to 13 carbon atoms, can also be selected as a substituent. This is possible. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl groups, ethyl groups, Propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hex Examples include syl groups. In addition, cycloalkyl groups having 3 to 7 carbon atoms can be used. In terms of composition, it consists of cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. Examples include the phenyl group. Naphthyl groups, biphenyl groups, and fluorenyl groups are some specific examples.

[0146] Also, Ar 1 This represents an arylene group or single bond having 6 to 25 carbon atoms, and the arylene The n group may have substituents, and these substituents may bond to each other to form a ring. For example, the carbon at position 9 of the fluorenyl group has a phenyl group as a substituent. It has two such phenyl groups, and these phenyl groups bond together to form a spirofluorene skeleton. Examples include the following cases. As for arylene groups having 6 to 25 carbon atoms, phenylene groups, Examples include naphthylene groups, biphenyldiyl groups, and fluoranyl groups. This can be done. Furthermore, if the arylene group has substituents, the substituents may be defined as having a carbon number. 1 to 6 alkyl groups, 3 to 7 cycloalkyl groups, or 6 to 13 C groups Aryl groups can also be selected as substituents. C1 to C6 alkyl groups include Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl Examples include the tert-butyl group, n-hexyl group, etc. Also, the 3-carbon group Specifically, the cycloalkyl groups up to 7 include cyclopropyl group, cyclobutyl group, and cyclopropyl group. Examples include lopentyl groups and cyclohexyl groups. Also, groups with 6 to 13 carbon atoms. Examples of aryl groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. This can be cited as an example.

[0147] Furthermore, in the compound of this embodiment, the benzoflopyrimidine skeleton is benzoflopyrimidine. It is preferable that the skeleton is [3,2-d]pyrimidine.

[0148] Furthermore, in the compound of this embodiment, the benzothienopyrimidine skeleton is benzo It is preferable that the skeleton be thieno[3,2-d]pyrimidine.

[0149] Furthermore, in the compound of this embodiment, one of the carbazoli of the bicarbazole skeleton At the 9-position of the ru group, directly or via the arylene group, benzofloxacin[3,2-d]pyriol The structure bonded to the 4th position of the midin skeleton or benzothieno[3,2-d]pyrimidine skeleton The compounds possess both strong donor and acceptor properties and have a broad band gap. Therefore, it can be suitably used in light-emitting elements that exhibit high-energy light, such as blue light. This is a suitable composition. The above compound is represented by the following general formula (G1).

[0150] [ka]

[0151] In the general formula (G1) above, Q represents oxygen or sulfur.

[0152] Also, R 1 ~R 20Each of these independently consists of hydrogen, substituted or unsubstituted carbon atoms with 1 or more carbon atoms. 6 alkyl groups, substituted or unsubstituted cycloalkyl groups having 3 to 7 carbon atoms, or substituted groups. Alternatively, it represents any of the unsubstituted aryl groups with 6 to 13 carbon atoms. Specifically, propyl groups include methyl, ethyl, propyl, isopropyl, and butyric groups. Examples include the 1xyl group, isobutyl group, tert-butyl group, and n-hexyl group. Furthermore, specific examples of cycloalkyl groups having 3 to 7 carbon atoms include cyclopropyl groups, cyclopropyl groups, and cyclopropyl groups. Examples include chlorobutyl groups, cyclopentyl groups, and cyclohexyl groups. Examples of aryl groups having 6 to 13 carbon atoms include phenyl, naphthyl, biphenyl, and flu. The olen group can be given as a specific example. Furthermore, the alkyl and cyclic groups mentioned above... The R-alkyl group and the aryl group may have substituents, and these substituents are bonded to each other. A ring may be formed. The substituent may be an alkyl group having 1 to 6 carbon atoms, or a ring having 3 carbon atoms. A cycloalkyl group with up to 7 carbon atoms, or an aryl group with 6 to 13 carbon atoms, can also be selected as a substituent. This is possible. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl groups, ethyl groups, Propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hex Examples include syl groups. In addition, cycloalkyl groups having 3 to 7 carbon atoms can be used. In terms of composition, it consists of cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. Examples include the phenyl group. Naphthyl groups, biphenyl groups, and fluorenyl groups are some specific examples.

[0153] Also, Ar 1This represents an arylene group or single bond having 6 to 25 carbon atoms, and the arylene The n group may have substituents, and these substituents may bond to each other to form a ring. For example, the carbon at position 9 of the fluorenyl group has a phenyl group as a substituent. It has two such phenyl groups, and these phenyl groups bond together to form a spirofluorene skeleton. Examples include the following cases. As for arylene groups having 6 to 25 carbon atoms, phenylene groups, Examples include naphthylene groups, biphenyldiyl groups, and fluoranyl groups. This can be done. Furthermore, if the arylene group has substituents, the substituents may be defined as having a carbon number. 1 to 6 alkyl groups, 3 to 7 cycloalkyl groups, or 6 to 13 C groups Aryl groups can also be selected as substituents. C1 to C6 alkyl groups include Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl Examples include the tert-butyl group, n-hexyl group, etc. Also, the 3-carbon group Specifically, the cycloalkyl groups up to 7 include cyclopropyl group, cyclobutyl group, and cyclopropyl group. Examples include lopentyl groups and cyclohexyl groups. Also, groups with 6 to 13 carbon atoms. Examples of aryl groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. This can be cited as an example.

[0154] Furthermore, in the compound of this embodiment, the bicarbazole skeleton is 3,3'-bi- It has a 9H-carbazole skeleton, and one of the carbazolyl groups of the bicarbazole skeleton is at position 9. In this process, the benzofl[3,2-d]pyrimidine skeleton is directly or via an allylene group. or compounds having a structure bonded at position 4 of the benzothieno[3,2-d]pyrimidine skeleton Because it has excellent carrier transport properties, light-emitting elements using it can be driven at a low voltage, which is advantageous. It has a suitable composition. The above compound is represented by the following general formula (G2).

[0155] [ka]

[0156] In the general formula (G2) above, Q represents oxygen or sulfur.

[0157] Also, R 1 ~R 20 Each of these independently consists of hydrogen, substituted or unsubstituted carbon atoms with 1 or more carbon atoms. 6 alkyl groups, substituted or unsubstituted cycloalkyl groups having 3 to 7 carbon atoms, or substituted groups. Alternatively, it represents any of the unsubstituted aryl groups with 6 to 13 carbon atoms. Specifically, propyl groups include methyl, ethyl, propyl, isopropyl, and butyric groups. Examples include the 1xyl group, isobutyl group, tert-butyl group, and n-hexyl group. Furthermore, specific examples of cycloalkyl groups having 3 to 7 carbon atoms include cyclopropyl groups, cyclopropyl groups, and cyclopropyl groups. Examples include chlorobutyl groups, cyclopentyl groups, and cyclohexyl groups. Examples of aryl groups having 6 to 13 carbon atoms include phenyl, naphthyl, biphenyl, and flu. The olen group can be given as a specific example. Furthermore, the alkyl and cyclic groups mentioned above... The R-alkyl group and the aryl group may have substituents, and these substituents are bonded to each other. A ring may be formed. The substituent may be an alkyl group having 1 to 6 carbon atoms, or a ring having 3 carbon atoms. A cycloalkyl group with up to 7 carbon atoms, or an aryl group with 6 to 13 carbon atoms, can also be selected as a substituent. This is possible. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl groups, ethyl groups, Propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hex Examples include syl groups. In addition, cycloalkyl groups having 3 to 7 carbon atoms can be used. In terms of composition, it consists of cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. Examples include the phenyl group. Naphthyl groups, biphenyl groups, and fluorenyl groups are some specific examples.

[0158] Also, Ar 1 This represents an arylene group or single bond having 6 to 25 carbon atoms, and the arylene The n group may have substituents, and these substituents may bond to each other to form a ring. For example, the carbon at position 9 of the fluorenyl group has a phenyl group as a substituent. It has two such phenyl groups, and these phenyl groups bond together to form a spirofluorene skeleton. Examples include the following cases. As for arylene groups having 6 to 13 carbon atoms, phenylene groups, Examples include naphthylene groups, biphenyldiyl groups, and fluoranyl groups. This can be done. Furthermore, if the arylene group has substituents, the substituents may be defined as having a carbon number. 1 to 6 alkyl groups, 3 to 7 cycloalkyl groups, or 6 to 13 C groups Aryl groups can also be selected as substituents. C1 to C6 alkyl groups include Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl Examples include the tert-butyl group, n-hexyl group, etc. Also, the 3-carbon group Specifically, the cycloalkyl groups up to 7 include cyclopropyl group, cyclobutyl group, and cyclopropyl group. Examples include lopentyl groups and cyclohexyl groups. Also, groups with 6 to 13 carbon atoms. Examples of aryl groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. This can be cited as an example.

[0159] Furthermore, in the compound of this embodiment, the bicarbazole skeleton and benzoflopyl If it has a structure in which the midin skeleton or the benzothienopyrimidine skeleton is directly bound, This configuration is preferable because it widens the end gap and allows for synthesis with high purity. Furthermore, because this compound has excellent carrier transport properties, light-emitting devices using it are low It can be driven with a low voltage.

[0160] Furthermore, in the above general formula (G1) or (G2), R 1 ~R 14 , and R 16 ~ R 20 However, if it is all hydrogen, it is advantageous in terms of ease of synthesis and the price of raw materials, and further Furthermore, because it results in a compound with a relatively low molecular weight, it has a structure suitable for vacuum deposition, which is particularly preferable. The compound in question is represented by the following general formula (G3) or general formula (G4).

[0161] [ka]

[0162] In the above general formula (G3), Q represents oxygen or sulfur.

[0163] Also, R 15 This includes hydrogen, substituted or unsubstituted C1-C6 alkyl groups, and substituted or or an unsubstituted cycloalkyl group having 3 to 7 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 6 carbon atoms. It represents any of the aryl groups from 1 to 13. Specifically, alkyl groups having 1 to 6 carbon atoms are... methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, te Examples include rt-butyl groups and n-hexyl groups. Also, groups with 3 to 7 carbon atoms. Specifically, examples of cloalkyl groups include cyclopropyl group, cyclobutyl group, and cyclopene group. Examples include cyclohexyl groups and cyclohexyl groups. Also, ally groups with 6 to 13 carbon atoms. Examples of fluorenyl groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. These can be listed as follows. Furthermore, the alkyl groups, cycloalkyl groups, and aryl groups mentioned above. The group may have substituents, and these substituents may bond to each other to form a ring. The substituents include alkyl groups having 1 to 6 carbon atoms, cycloalkyl groups having 3 to 7 carbon atoms, Alternatively, aryl groups having 6 to 13 carbon atoms can also be selected as substituents. Specifically, alkyl groups up to 6 include methyl group, ethyl group, propyl group, and isopropyl group. Examples include the butyl group, isobutyl group, tert-butyl group, and n-hexyl group. Yes, it is possible. Specifically, examples of cycloalkyl groups with 3 to 7 carbon atoms include cyclopropyl Examples include the cyclobutyl group, cyclopentyl group, and cyclohexyl group. Furthermore, aryl groups having 6 to 13 carbon atoms include phenyl groups, naphthyl groups, and biphenyl groups. Fluorenyl groups can be given as specific examples.

[0164] Also, Ar 1 This represents an arylene group or single bond having 6 to 25 carbon atoms, and the arylene The n group may have substituents, and these substituents may bond to each other to form a ring. For example, the carbon at position 9 of the fluorenyl group has a phenyl group as a substituent. It has two such phenyl groups, and these phenyl groups bond together to form a spirofluorene skeleton. Examples include the following cases. As for arylene groups having 6 to 25 carbon atoms, phenylene groups, Examples include naphthylene groups, biphenyldiyl groups, and fluoranyl groups. This can be done. Furthermore, if the arylene group has substituents, the substituents may be defined as having a carbon number. 1 to 6 alkyl groups, 3 to 7 cycloalkyl groups, or 6 to 13 C groups Aryl groups can also be selected as substituents. C1 to C6 alkyl groups include Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl Examples include the tert-butyl group, n-hexyl group, etc. Also, the 3-carbon group Specifically, the cycloalkyl groups up to 7 include cyclopropyl group, cyclobutyl group, and cyclopropyl group. Examples include lopentyl groups and cyclohexyl groups. Also, groups with 6 to 13 carbon atoms. Examples of aryl groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. This can be cited as an example.

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[0166] In the general formula (G4) above, Q represents oxygen or sulfur.

[0167] Also, R 15 This includes hydrogen, substituted or unsubstituted C1-C6 alkyl groups, and substituted or or an unsubstituted cycloalkyl group having 3 to 7 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 6 carbon atoms. It represents any of the aryl groups from 1 to 13. Specifically, alkyl groups having 1 to 6 carbon atoms are... methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, te Examples include rt-butyl groups and n-hexyl groups. Also, groups with 3 to 7 carbon atoms. Specifically, examples of cloalkyl groups include cyclopropyl group, cyclobutyl group, and cyclopene group. Examples include cyclohexyl groups and cyclohexyl groups. Also, ally groups with 6 to 13 carbon atoms. Examples of fluorenyl groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. These can be listed as follows. Furthermore, the alkyl groups, cycloalkyl groups, and aryl groups mentioned above. The group may have substituents, and these substituents may bond to each other to form a ring. The substituents include alkyl groups having 1 to 6 carbon atoms, cycloalkyl groups having 3 to 7 carbon atoms, Alternatively, aryl groups having 6 to 13 carbon atoms can also be selected as substituents. Specifically, alkyl groups up to 6 include methyl group, ethyl group, propyl group, and isopropyl group. Examples include the butyl group, isobutyl group, tert-butyl group, and n-hexyl group. Yes, it is possible. Specifically, examples of cycloalkyl groups with 3 to 7 carbon atoms include cyclopropyl Examples include the cyclobutyl group, cyclopentyl group, and cyclohexyl group. Furthermore, aryl groups having 6 to 13 carbon atoms include phenyl groups, naphthyl groups, and biphenyl groups. Fluorenyl groups can be given as specific examples.

[0168] Also, Ar 1 This represents an arylene group or single bond having 6 to 25 carbon atoms, and the arylene The n group may have substituents, and these substituents may bond to each other to form a ring. For example, the carbon at position 9 of the fluorenyl group has a phenyl group as a substituent. It has two such phenyl groups, and these phenyl groups bond together to form a spirofluorene skeleton. Examples include the following cases. As for arylene groups having 6 to 25 carbon atoms, phenylene groups, Examples include naphthylene groups, biphenyldiyl groups, and fluoranyl groups. This can be done. Furthermore, if the arylene group has substituents, the substituents may be defined as having a carbon number. 1 to 6 alkyl groups, 3 to 7 cycloalkyl groups, or 6 to 13 C groups Aryl groups can also be selected as substituents. C1 to C6 alkyl groups include Specifically, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl Examples include the tert-butyl group, n-hexyl group, etc. Also, the 3-carbon group Specifically, the cycloalkyl groups up to 7 include cyclopropyl group, cyclobutyl group, and cyclopropyl group. Examples include lopentyl groups and cyclohexyl groups. Also, groups with 6 to 13 carbon atoms. Examples of aryl groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. This can be cited as an example.

[0169] In the general formula (G0), the benzophropyrimidine skeleton or benzothophyll is represented as A. For example, the enopyrimidine skeleton is represented by the following structural formulas (Ht-1) to (Ht-24). The structure can be applied. Note that the structures that can be used as A are these It is not limited to that.

[0170] [ka]

[0171] [ka]

[0172] In the above structural formulas (Ht-1) to (Ht-24), R 16 ~R 20 These are, Independently, hydrogen, substituted or unsubstituted C1 to C6 alkyl groups, substituted or unsubstituted A cycloalkyl group having 3 to 7 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 6 to 13 carbon atoms. It represents any of the aryl groups. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl Examples include cycloalkyl groups and n-hexyl groups. Also, cycloalkyl groups having 3 to 7 carbon atoms. Specifically, the cyclopropyl group includes cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclopropyl group. Examples include chlorohexyl groups. Also, as aryl groups having 6 to 13 carbon atoms... Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. Furthermore, the alkyl, cycloalkyl, and aryl groups mentioned above can be substituted. The substituents may have groups, and the substituents may bond to each other to form a ring. For example, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms, or carbon Aryl groups with 6 to 13 carbon atoms can also be selected as substituents. Specifically, methyl, ethyl, propyl, isopropyl, and butyl groups are examples of methyl, ethyl, propyl, isopropyl, and butyl groups. Examples include the isobutyl group, tert-butyl group, and n-hexyl group. Specifically, examples of cycloalkyl groups having 3 to 7 carbon atoms include cyclopropyl groups and cyclo Examples include butyl groups, cyclopentyl groups, and cyclohexyl groups. Also, carbon Examples of aryl groups numbered 6 to 13 include phenyl, naphthyl, biphenyl, and fluorescein groups. The yl group can be given as a specific example.

[0173] Furthermore, in general formulas (G0) and (G1), it can be used as the bicarbazole skeleton. Possible structures include, for example, structures represented by the following structural formulas (Cz-1) to (Cz-9). This can be applied. Note that the structures that can be used as the bicarbazole skeleton are as follows: It is not limited to these.

[0174] [ka]

[0175] [ka]

[0176] In the above structural formulas (Cz-1) to (Cz-9), R 1 ~R 15 Each is independent in addition, hydrogen, substituted or unsubstituted C1 to C6 alkyl groups, substituted or unsubstituted carbon Cycloalkyl groups with 3 to 7 prime atoms, or substituted or unsubstituted ali groups with 6 to 13 carbon atoms. It represents any of the alkyl groups. Specifically, alkyl groups having 1 to 6 carbon atoms include the methyl group, Ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group Examples include n-hexyl groups. Also, cycloalkyl groups having 3 to 7 carbon atoms. Specifically, these include cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclo Examples include hexyl groups. Also, as for aryl groups having 6 to 13 carbon atoms, Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. This can be achieved. Furthermore, the alkyl, cycloalkyl, and aryl groups mentioned above have substituents. They may have, and the substituents may bond to each other to form a ring. This includes alkyl groups having 1 to 6 carbon atoms, cycloalkyl groups having 3 to 7 carbon atoms, or C6 Aryl groups of up to 13 carbon atoms can also be selected as substituents. Alkyl groups having 1 to 6 carbon atoms. Specifically, the groups include methyl group, ethyl group, propyl group, isopropyl group, and butyl group. Examples include isobutyl groups, tert-butyl groups, and n-hexyl groups. Examples of cycloalkyl groups having 3 to 7 carbon atoms include cyclopropyl group, cyclobutyl group, etc. Examples include the cyclopentyl group, cyclohexyl group, etc. Also, a group with 6 carbon atoms. The aryl groups up to 13 include phenyl, naphthyl, biphenyl, and fluorenyl groups. Examples such as the basics can be given as concrete examples.

[0177] Furthermore, in the above general formulas (G0) to (G4), Ar 1 The arylene group represented by is For example, groups represented by the following structural formulas (Ar-1) to (Ar-27) can be applied. Ar 1 The groups that can be used as such are not limited to these, and include groups having substituents. You can.

[0178] [ka]

[0179] [ka]

[0180] Furthermore, R in the above general formulas (G1) and (G2) 1 ~R 20 , R of the general formula (G0) 1 ~ R15 , R of general formulas (G3) and (G4) 15 alkyl groups and cycloalkyl groups represented by , A group, or aryl group, is a group represented by the following structural formulas (R-1) to (R-29). This can be applied. Note that alkyl groups, cycloalkyl groups, or aryl groups may be used. The groups that can be used are not limited to these, and may also have substituents.

[0181] [ka]

[0182] ≪Specific Examples of Compounds≫ The specific structures of the compounds represented by the above general formulas (G0) to (G4) are as follows: Examples include compounds represented by structural formulas (100) to (147). Note that general formula (G The compounds represented as 0) through (G4) are not limited to the following examples.

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[0184] [ka]

[0185] [ka]

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[0188] [ka]

[0189] [ka]

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[0191] Furthermore, the host material 132 has singlet excitation energy levels and triplet excitation energy levels A small energy difference is preferable, but a high reverse intersystem crossing efficiency is not necessarily required. The emission quantum yield does not need to be high, and it does not need to have the function of exhibiting thermally activated delayed fluorescence. In that case, the host material 132 is a skeleton or aromatic amine having a π-electron-rich heteroaromatic ring. At least one of the n skeletons and a skeleton having a π-electron-deficient heteroaromatic ring are m-phenylene It has a structure that is bonded via a structure having at least one of a group or an o-phenylene group. This is preferable. Alternatively, bonding via a biphenyldiyl group is preferable. i is an arylene group having at least one m-phenylene group or an o-phenylene group. It is preferable that the structure is bonded via a biphenyldiyl group, and the arylene group is a biphenyldiyl group It is even more preferable if the host material 132 has the above-described structure. The T1 level of 2 can be raised. In this case as well, the π-electron-deficient complex aroma The skeleton containing the ring is the diazine skeleton (pyrimidine skeleton, pyrazine skeleton, pyridazine skeleton). Preferably, it has a triazine skeleton. Also, it has a π-electron-rich heteroaromatic ring. The skeletons are acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, furan skeleton, and Having one or more selected from the offen skeleton and the pyrrole skeleton. However, this is preferable. Furthermore, the dibenzofuran skeleton is preferred as the furan skeleton, and the thiophene skeleton is preferred. The dibenzothiophene skeleton is preferred for each of these. The pyrrole skeleton is Indian 3-(9-phenyl-9H-carbazole-3-yl) skeleton, carbazole skeleton, and 3-(9-phenyl-9H-carbazole-3-yl) A )-9H-carbazole skeleton is particularly preferred. Also, as an aromatic amine skeleton, NH A so-called tertiary amine that does not have a bond is preferred, and a triarylamine skeleton is particularly preferred. i. The aryl group of the triarylamine skeleton has 6 to 5 carbon atoms forming the ring. 13 substituted or unsubstituted aryl groups are preferred, including phenyl, naphthyl, and fluorenyl groups. Examples include the foundation.

[0192] Examples of the above aromatic amine skeleton and skeletons having a π-electron-rich heteroaromatic ring include: The skeleton is represented by the following general formulas (401) to (417). Note that general formula (413) In (416), X represents either an oxygen atom or a sulfur atom.

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[0194] Furthermore, an example of a skeleton having the above-mentioned π-electron-deficient heteroaromatic ring is the following general formula (20 1) The skeleton is represented by (218).

[0195] [ka]

[0196] Hole-transporting skeletons (specifically, π-electron-rich heteroaromatic ring skeletons or aromatic amines) (at least one of the skeletons) and a skeleton with electron transport properties (specifically, a π-electron-deficient complex aromatic A ring skeleton and a bond having at least one m-phenylene group or an o-phenylene group. When bonding occurs via a group, when bonding occurs via a biphenyldiyl group as a bonding group, It has an arylene group having at least one m-phenylene group or an o-phenylene group. When bonding occurs via a bonding group, an example of such a bonding group is the following general formula (301) to This is the skeleton represented by (315). Note that the above arylene group is the phenylene skeleton. , biphenyldiyl skeleton, naphthalenediyl skeleton, fuloangularyl skeleton, phenanthr Examples include the rudimentary skeleton.

[0197] [ka]

[0198] The above-mentioned aromatic amine skeleton (specifically, the triarylamine skeleton), π-electron-rich complex Aromatic ring skeletons (specifically acridine skeleton, phenoxazine skeleton, phenothiazine skeleton, f Rings having a ranic skeleton, thiophene skeleton, or pyrrole skeleton, π-electron-deficient heteroaromatic ring skeleton ( Specifically, a ring having a diazine skeleton or a triazine skeleton, or the general formula (4) 01) to (417), general formulas (201) to (218), and general formulas (301) to ( 315) may have substituents. Such substituents may have 1 to 6 carbon atoms. Alkyl groups, cycloalkyl groups with 3 to 6 carbon atoms, or groups with 6 to 12 carbon atoms. A substituted or unsubstituted aryl group can also be selected as a substituent. (1 to 1 carbon atom) Examples of C6 alkyl groups include methyl, ethyl, propyl, and isopropyl groups. Examples include pyr group, butyl group, isobutyl group, tert-butyl group, n-hexyl group, etc. This can be done. In addition, as a cycloalkyl group having 3 to 6 carbon atoms, specifically, Examples include cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl group. This can be done. In addition, as aryl groups having 6 to 12 carbon atoms, phenyl groups, naphthium groups can be used. Specific examples include the 14-unit group and the biphenyl group. They may combine to form a ring. An example of this is, for example, in a fluorene skeleton. If the carbon atom at position 9 has two phenyl groups as substituents, these phenyl groups bond together. This can lead to the formation of a spirofluorene skeleton. In this case, it is advantageous in terms of ease of synthesis and the price of raw materials.

[0199] Also, Ar 2 This represents an arylene group having 6 to 13 carbon atoms, and the arylene group is They may have substitution groups, and these substituents may bond to each other to form a ring. Examples include... For example, the carbon at position 9 of the fluorenyl group has two phenyl groups as substituents. In a field where the phenyl groups bond together to form a spirofluorene skeleton Examples include arylene groups having 6 to 13 carbon atoms, such as phenylene groups and naphthene groups. Specific examples include the ethylene group, biphenylene group, and fluoroorangeyl group. Furthermore, if the arylene group has substituents, such substituents may be C1 to C1. A 6-C1 alkyl group, a cycloalkyl group with 3 to 6 C1s, or a group with 6 to 6 C1s Aryl groups with 12 carbon atoms can also be selected as substituents. Specifically, methyl, ethyl, propyl, isopropyl, and butyl groups are examples of methyl, ethyl, propyl, isopropyl, and butyl groups. Examples include the isobutyl group, tert-butyl group, and n-hexyl group. Specifically, as cycloalkyl groups having 3 to 6 carbon atoms, the cyclopropyl group is Examples include cyclobutyl groups, cyclopentyl groups, and cyclohexyl groups. Examples of aryl groups having 6 to 12 carbon atoms include phenyl, naphthyl, and biphenyl groups. Examples such as the basics can be given as concrete examples.

[0200] Also, Ar 2 The arylene group represented by the above structural formula (Ar-1) to (Ar The group represented by -18) can be applied. Note that Ar 2 Can be used as The basis is not limited to these.

[0201] Also, R 21 and R 22 These are, independently, hydrogen and an alkyl group having 1 to 6 carbon atoms. The group, a cycloalkyl group having 3 to 6 carbon atoms, or a substitution with 6 to 13 carbon atoms are also possible. It represents either an unsubstituted aryl group or an alkyl group having 1 to 6 carbon atoms. Specifically, these include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group. Examples include the 3-C1 group, tert-butyl group, and n-hexyl group. Specifically, examples of cycloalkyl groups having 6 or more carbon atoms include cyclopropyl groups and cyclobutyl groups. Examples include the cyclopentyl group, cyclohexyl group, etc. Also, a group with 6 carbon atoms. Examples of aryl groups having 13 carbon atoms include phenyl, naphthyl, biphenyl, and fluorine groups. Renyl groups can be given as specific examples. Furthermore, the aryl groups and phenyl groups mentioned above can also be cited. The group may have substituents, and these substituents may be bonded to each other to form a ring. Substituents include alkyl groups having 1 to 6 carbon atoms, and cycloalkyl groups having 3 to 6 carbon atoms. A aryl group or an aryl group having 6 to 12 carbon atoms can also be selected as a substituent. It is possible. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl groups, ethyl groups, and propyl groups. Ropyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hexyl Examples include C3 to C6 cycloalkyl groups. Specifically, these are cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl Examples include groups such as carbon atoms. In addition, as aryl groups having 6 to 12 carbon atoms, f Specific examples include phenyl groups, naphthyl groups, and biphenyl groups.

[0202] Also, R 21 and R 22 The alkyl or aryl group represented by the above structure is, for example, Groups represented by formulas (R-1) to (R-29) can be applied. The groups that can be used as aryl groups are not limited to these.

[0203] Also, general formulas (401) to (417), general formulas (201) to (218), general formula ( 301) to (315), and Ar 2 , R 21 and R 22 The substituents that can be present are For example, alkyl groups or aryl groups represented by the above structural formulas (R-1) to (R-24). The group can be applied. It can be used as an alkyl group or an aryl group. The basis is not limited to these.

[0204] Furthermore, the emission peak exhibited by the host material 132 is triple that of the guest material 131 (phosphorescent material). Term MLCT (Metal to Ligand Charge Transfer) transition The absorption band, more specifically, the absorption band on the longest wavelength side, is overlapped with the host material 132. It is preferable to select guest material 131 (phosphorescent material). This improves the luminescence efficiency. This can result in a dramatically improved light-emitting element. However, instead of phosphorescent material, a thermal activation delay can be used. When using fluorescent materials, the absorption band on the longest wavelength side is the singlet absorption band. preferable.

[0205] ≪Guest Material 131≫ Guest material 131 (phosphorescent material) can be iridium, rhodium, or platinum-based organic Examples include metal complexes, or metal complexes in particular, organoiridium complexes, such as iridium Orthometallic complexes are preferred. 4H-triazole is a suitable ligand for orthometallation. Ligands, 1H-triazole ligands, imidazole ligands, pyridine ligands, pyrimidines Examples include ligands, pyrazine ligands, or isoquinoline ligands. Examples include platinum complexes having porphyrin ligands.

[0206] Furthermore, as guest material 131 (phosphorescent material), the LUMO level of host material 132 is It has a high LUMO level and a HOMO level lower than that of the host material 132. Therefore, it is preferable to select host material 132 and guest material 131 (phosphorescent material). This allows for the creation of a light-emitting element with high luminous efficiency and that can be driven at a low voltage.

[0207] Examples of substances that have a green or yellow emission peak include tris(4-methyl-6) -Phenylpyrimidina) Iridium(III) (abbreviation: Ir(mppm)3), Tris (4-t-butyl-6-phenylpyrimidinato)iridium(III) (abbreviation: Ir(t) Buppm)3), (acetylacetonate)bis(6-methyl-4-phenylpyrimidina Iridium(III) (abbreviation: Ir(mppm)2(acac)), (acetylacetate) Tonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) )(Abbreviation: Ir(tBuppm)2(acac)), (acetylacetonato)bis[4- (2-norbornyl)-6-phenylpyrimidinato]iridium(III) (abbreviation: Ir (nbppm)2(acac)), (acetylacetonato)bis[5-methyl-6-(2 -methylphenyl)-4-phenylpyrimidinato]iridium(III) (abbreviation: Ir( mpmppm)2(acac)), (acetylacetonato)bis{4,6-dimethyl-2 -[6-(2,6-dimethylphenyl)-4-pyrimidinyl-κN3]phenyl-κC} Iridium(III) (abbreviation: Ir(dmppm-dmp)2(acac)), (acetyl Luacetonato)bis(4,6-diphenylpyrimidinato)iridium(III) (abbreviation: Organometallic iridium with a pyrimidine skeleton, such as Ir(dppm)2(acac)). Complexes, and (acetylacetonato)bis(3,5-dimethyl-2-phenylpyradinato) Lydium(III) (abbreviation: Ir(mppr-Me)2(acac)), (acetylacetate Tonato)bis(5-isopropyl-3-methyl-2-phenylpyradinato)iridium III) (abbreviation: Ir(mppr-iPr)2(acac)) has a pyrazine skeleton organometallic iridium complexes and tris(2-phenylpyridinato-N,C) 2’ ) Iridi Um(III) (abbreviation: Ir(ppy)3), bis(2-phenylpyridinato-N,C) 2 ’ Iridium(III) acetylacetonate (abbreviation: Ir(ppy)2(acac)) ), bis(benzo[h]quinolinate)iridium(III)acetylacetonate (abbreviation) :Ir(bzq)2(acac)), Tris(benzo[h]quinolinate) Iridium(I II) (Abbreviation: Ir(bzq)3), Tris(2-phenylquinolinato-N,C) 2’ )stomach Lydium(III) (abbreviation: Ir(pq)3), bis(2-phenylquinolinato-N,C) 2’ Iridium(III) acetylacetonate (abbreviation: Ir(pq)2(acac)) Organometallic iridium complexes having a pyridine skeleton, such as bis(2,4-diphenyl -1,3-Oxazolato-N,C 2’ ) Iridium(III) acetylacetonate (abbreviated) Name: Ir(dpo)2(acac)), bis{2-[4'-(perfluorophenyl)f [enyl]pyridinate-N,C 2’ Iridium(III) acetylacetonate (abbreviation: Ir(p-PF-ph)2(acac)), bis(2-phenylbenzothiazolat-N, C 2’ Iridium(III) acetylacetonate (abbreviation: Ir(bt)2(acac) In addition to organometallic iridium complexes such as )), tris(acetylacetonate)(monophenant Rare earth elements such as terbium(III) (abbreviation: Tb(acac)3(Phen)) Examples include metal-type complexes. Among those mentioned above, organometallic iridium with a pyrimidine skeleton is particularly noteworthy. The complex is particularly preferred because it exhibits outstanding reliability and luminescence efficiency.

[0208] Furthermore, examples of substances that have a yellow or red emission peak include (diisobutyryl Methanato)bis[4,6-bis(3-methylphenyl)pyrimidinato]iridium(II) I) (abbreviation: Ir(5mdppm)2(dibm)), bis[4,6-bis(3-methyl [Phenyl)pyrimidinato](dipivaloylmethanato)iridium(III) (abbreviation: Ir (5 mdppm)2(dpm)), bis[4,6-di(naphthalene-1-yl)pyrimid Nat] (dipivaloylmethanato) Iridium(III) (Abbreviation: Ir(d1npm)2) Organometallic iridium complexes having a pyrimidine skeleton such as dpm, and (acetylacet Tonato)bis(2,3,5-triphenylpyradinato)iridium(III) (abbreviation: I r(tppr)2(acac)), bis(2,3,5-triphenylpyrazinate)(dipy Valoylmethanato) Iridium(III) (abbreviation: Ir(tppr)2(dpm)), ( Acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxalinato] A pyrazine skeleton like lysium(III) (abbreviation: Ir(Fdpq)2(acac)) The organometallic iridium complexes and tris(1-phenylisoquinolinato-N,C) 2’ ) Iridium(III) (abbreviation: Ir(piq)3), bis(1-phenylisoquinolinate) -N,C 2’ ) Iridium(III) acetylacetonate (abbreviation: Ir(piq)2( In addition to organometallic iridium complexes with a pyridine skeleton such as acac), 2, 3, 7, 8,12,13,17,18-Octaethyl-21H,23H-Porphyrin Platinum(II) Platinum complexes such as (abbreviation: PtOEP) and tris(1,3-diphenyl-1,3-p Europium(III) (Abbreviation: Eu(DB) M)3(Phen)), Tris[1-(2-tenoyl)-3,3,3-trifluoroacetate Tonato (monophenanthroline) europium(III) (abbreviation: Eu(TTA)3) Examples include rare earth metal complexes such as Phen). Among those mentioned above, the pyrimidine skeleton The organometallic iridium complex possesses outstanding reliability and luminescence efficiency, and is therefore particularly preferred. Furthermore, organometallic iridium complexes having a pyrazine skeleton can produce a red emission with good chromaticity. It is possible.

[0209] Furthermore, examples of substances that have a blue or green emission peak include Tris{2-[5 -(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4- [Riazole-3-yl-κN2]phenyl-κC}iridium(III) (abbreviation: Ir( mpptz-dmp)3), Tris(5-methyl-3,4-diphenyl-4H-1,2, 4-Triazolat) Iridium(III) (abbreviation: Ir(Mptz)3), Tris[4- (3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazola Tris[3-(5]) [-biphenyl)-5-isopropyl-4-phenyl-4H-1,2,4-triazolato] Iridium(III) (abbreviation: Ir(iPr5btz)3), such as 4H-triazole iridium organometallic complexes having a 3-methyl skeleton, and tris[3-methyl-1-(2-methylphenyl] [Nyl)-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-Triazolat) Iridium(III) (Abbreviation: Ir(Prptz1- Organometallic iridium complexes having a 1H-triazole skeleton, such as Me)3), and fac -Tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazo Iridium(III) (abbreviation: Ir(iPrpmi)3), Tris[3-(2,6- Dimethylphenyl)-7-methylimidazo[1,2-f]phenantridinato]iridiu It has an imidazole skeleton like Mu(III) (abbreviation: Ir(dmpimpt-Me)3) organometallic iridium complexes and bis[2-(4',6'-difluorophenyl)pyridium Nato-N,C 2’ Iridium(III) tetrakis(1-pyrazolyl) borate (abbreviation) :FIr6), bis[2-(4',6'-difluorophenyl)pyridinate-N,C 2’ Iridium(III) picolinate (abbreviation: Firpic), bis{2-[3',5' -Bis(trifluoromethyl)phenyl]pyridinate-N,C 2’ Iridium (III ) Picolinate (abbreviation: Ir(CF3ppy)2(pic)), Bis[2-(4',6' -Difluorophenyl)pyridinate-N,C 2’ Iridium(III) acetylacetate Phenylpyridine derivatives with electron-withdrawing groups, such as NART (abbreviated as FIr(acac)). Examples include organometallic iridium complexes that use the isomer as a ligand. Among those mentioned above, 4H-tria Nitrogen-containing five-membered heterocycles such as zole skeletons, 1H-triazole skeletons, and imidazole skeletons Organometallic iridium complexes with a skeletal structure possess high triplet excitation energies, and are reliable and powerful. It is particularly preferable because it also has excellent light efficiency.

[0210] Furthermore, among organometallic iridium complexes having a nitrogen-containing five-membered heterocyclic skeleton, at least shea Iridium complexes having substituents containing a cyano group are LUM due to the strong electron-withdrawing properties of the cyano group. Because the O level and HOMO level are lowered, it is suitable for use in a light-emitting element according to one embodiment of the present invention. This is possible. Furthermore, the iridium complex has a high triplet excitation energy level. Furthermore, by using the iridium complex in a light-emitting element, a blue light with good luminescence efficiency is produced. It is possible to fabricate devices. Furthermore, the iridium complex is suitable for repeated oxidation and reduction. Because it has good resistance, using this iridium complex in a light-emitting element extends the operating life. A good light-emitting element can be fabricated.

[0211] Furthermore, from the viewpoint of device characteristics stability and reliability, a cyano group is added to the nitrogen-containing five-membered heterocyclic skeleton. It is preferable that the iridium complex has a ligand to which an aryl group is bonded, and the aryl The iridium group preferably has 6 to 13 carbon atoms. In this case, the iridium complex is Because vacuum deposition can be performed at relatively low temperatures, degradation such as thermal decomposition during deposition is less likely to occur.

[0212] Furthermore, the nitrogen atom in the nitrogen-containing five-membered heterocyclic skeleton bonds with the cyano group via the arylene group. Iridium complexes with combined ligands can maintain high triplet excitation energy levels. Therefore, it can be suitably used in light-emitting elements that exhibit high-energy light, such as blue light. It can do so. Furthermore, it exhibits high-energy luminescence, such as blue light, compared to cases without a cyano group. Furthermore, highly efficient light-emitting elements can be obtained. This allows for the creation of reliable light-emitting elements that exhibit high-energy light, such as blue light. It also has the characteristic of being able to do so. Furthermore, between the above nitrogen-containing five-membered heterocyclic skeleton and the cyano group, It is preferable that the bond is formed via an arylene group such as a nilen group.

[0213] Furthermore, if the number of carbon atoms in the arylene group is between 6 and 13, the iridium complex is comparative Because it is a low molecular weight compound, it is suitable for vacuum deposition (vacuum deposition can be performed at relatively low temperatures). It becomes a substance. Also, generally speaking, if the molecular weight is low, the heat resistance after film formation is often poor, but Because this iridium complex has multiple ligands, it has sufficient heat resistance even if the molecular weight of the ligands is low. It has the advantage of ensuring sexual intercourse.

[0214] In other words, the iridium complex, in addition to the ease of deposition and electrochemical stability mentioned above, It also has the characteristic of having a high triplet excitation energy level. Therefore, one aspect of the present invention In light-emitting devices, it is preferable to use the iridium complex as the guest material for the light-emitting layer. Yes, it is. In particular, it is more suitable for use as a guest material in blue light-emitting devices.

[0215] Examples of iridium complexes The iridium complex described above is an iridium complex represented by the following general formula (G11).

[0216] [ka]

[0217] In the above general formula (G11), Ar 11 and Ar 12 Each of them independently has 6 carbon atoms. Represents aryl groups with 6 to 13 carbon atoms, either substituted or unsubstituted. Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. This is possible. If the aryl group has substituents, the substituents may be C1-1 atoms. Alkyl alkyl groups up to 6 carbon atoms, cycloalkyl groups with 3 to 6 carbon atoms, or substitutions with 6 to 13 carbon atoms. Alternatively, an unsubstituted aryl group can also be selected as a substituent. (A group having 1 to 6 carbon atoms) Specifically, propyl groups include methyl, ethyl, propyl, isopropyl, and butyric groups. Examples include the 1xyl group, isobutyl group, tert-butyl group, and n-hexyl group. Furthermore, specific examples of cycloalkyl groups having 3 to 6 carbon atoms include cyclopropyl groups, cyclopropyl groups, and cyclopropyl groups. Examples include chlorobutyl groups, cyclopentyl groups, and cyclohexyl groups. Examples of aryl groups having 6 to 13 carbon atoms include phenyl, naphthyl, biphenyl, and flu. The olen group can be given as a specific example.

[0218] Also, Q 1 and Q 2 Each of these independently represents N or CR, where R is hydrogen and the number of carbon atoms. A C1 to C6 alkyl group, a C1 to C6 haloalkyl group, or a C6 to C13 alkyl group This represents a substituted or unsubstituted aryl group. Note that Q 1 and Q 2 At least one of them is CR It has. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, and pro groups. Pyr group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hexyl Examples include groups. Furthermore, as for haloalkyl groups having 1 to 6 carbon atoms, there are few. At least one hydrogen atom is combined with a Group 17 element (fluorine, chlorine, bromine, iodine, astatine) Substituted alkyl groups, including alkyl fluorides, alkyl chlorides, alkyl bromides, Examples include alkyl iodides, specifically methyl fluoride groups, methyl chloride groups, and fluoride Examples include ethyl groups and ethyl chloride groups, but the number of halogen elements contained or There may be one or more types. Also, aryl compounds with 6 to 13 carbon atoms. Examples of these groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. The following can be listed. Furthermore, the aryl group may have substituents, and the substitution The groups may be bonded to each other to form a ring. The substituent may be an alkyl group having 1 to 6 carbon atoms. The group may also be substituted with an aryl group, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 13 carbon atoms. It can be selected as a base. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl propyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-propyl group Examples include cycloaldehyde groups with 3 to 6 carbon atoms. Specifically, the kill group includes cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclopropyl group. Examples include chlorohexyl groups. Also, as aryl groups having 6 to 13 carbon atoms... Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. It is possible.

[0219] Also, Ar 11 and Ar 12 The aryl group represented by and the aryl group represented by R, at least Another has a cyano group.

[0220] Furthermore, iridium complexes that can be suitably used in a light-emitting element according to one embodiment of the present invention include Preferably, it is an orthometallic complex. The iridium complex described above is given by the following general formula (G12) This is an iridium complex represented by [formula].

[0221] [ka]

[0222] In the above general formula (G12), Ar 11 This refers to substituted or unsubstituted carbon atoms with 6 to 13 carbon atoms. This represents an aryl group. Examples of aryl groups with 6 to 13 carbon atoms include the phenyl group, the naphthyl group, Biphenyl groups and fluorenyl groups can be given as specific examples. If it has substituents, such substituents may be C1 to C6 alkyl groups, C3 alkyl groups, etc. Cycloalkyl groups up to 6 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 13 carbon atoms. They can be selected as substituents. Specifically, alkyl groups having 1 to 6 carbon atoms include: Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert Examples include butyl groups and n-hexyl groups. Also, cyclo groups having 3 to 6 carbon atoms. Specifically, alkyl groups include cyclopropyl, cyclobutyl, and cyclopentyl groups. Examples include groups such as cyclohexyl groups. Also, aryl groups having 6 to 13 carbon atoms. Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. It can be listed.

[0223] Also, R 31 ~R 34 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon Cycloalkyl groups with 3 to 6 prime numbers, and substituted or unsubstituted aryl groups with 6 to 13 carbon atoms. It represents either a cyano group or a C1-C6 alkyl group. Specifically, C1-C6 alkyl groups include: Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert Examples include butyl groups and n-hexyl groups. Also, cyclo groups having 3 to 6 carbon atoms. Specifically, alkyl groups include cyclopropyl, cyclobutyl, and cyclopentyl groups. Examples include groups such as cyclohexyl groups. Also, aryl groups having 6 to 13 carbon atoms. Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. It can be listed. Furthermore, R 31 ~R 34 The fact that they are all hydrogen makes synthesis easy. It is also advantageous in terms of raw material prices.

[0224] Also, Q 1 and Q 2 Each of these independently represents N or CR, where R is hydrogen and the number of carbon atoms. A C1 to C6 alkyl group, a C1 to C6 haloalkyl group, or a C6 to C13 alkyl group This represents a substituted or unsubstituted aryl group. Note that Q 1 and Q 2 At least one of them is CR It has. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, and pro groups. Pyr group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hexyl Examples include groups. Furthermore, as for haloalkyl groups having 1 to 6 carbon atoms, there are few. At least one hydrogen atom is combined with a Group 17 element (fluorine, chlorine, bromine, iodine, astatine) Substituted alkyl groups, including alkyl fluorides, alkyl chlorides, alkyl bromides, Examples include alkyl iodides, specifically methyl fluoride groups, methyl chloride groups, and fluoride Examples include ethyl groups and ethyl chloride groups, but the number of halogen elements contained or There may be one or more types. Also, aryl compounds with 6 to 13 carbon atoms. Examples of these groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. The following can be listed. Furthermore, the aryl group may have substituents, and the substitution The groups may be bonded to each other to form a ring. The substituent may be an alkyl group having 1 to 6 carbon atoms. The group may also be substituted with an aryl group, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 13 carbon atoms. It can be selected as a base. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl propyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-propyl group Examples include cycloaldehyde groups with 3 to 6 carbon atoms. Specifically, the kill group includes cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclopropyl group. Examples include chlorohexyl groups. Also, as aryl groups having 6 to 13 carbon atoms... Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. It is possible.

[0225] Also, Ar 11 and R 31 ~R 34 The aryl group represented by , the aryl group represented by R, and R 31 ~R 34 At least one of them has a cyano group.

[0226] Furthermore, in an iridium complex that can be suitably used in a light-emitting element according to one aspect of the present invention It has a 4H-triazole skeleton as a ligand, which gives it a high triplet excitation energy level. It can have positions and is particularly suitable for light-emitting elements that exhibit high-energy light, such as blue light. It is preferable because it can be used. The iridium complex described above is represented by the following general formula (G13). It is an iridium complex.

[0227] [ka]

[0228] In the above general formula (G13), Ar 11 This refers to substituted or unsubstituted carbon atoms with 6 to 13 carbon atoms. This represents an aryl group. Examples of aryl groups with 6 to 13 carbon atoms include the phenyl group, the naphthyl group, Biphenyl groups and fluorenyl groups can be given as specific examples. If it has substituents, such substituents may be C1 to C6 alkyl groups, C3 alkyl groups, etc. Cycloalkyl groups up to 6 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 13 carbon atoms. They can be selected as substituents. Specifically, alkyl groups having 1 to 6 carbon atoms include: Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert Examples include butyl groups and n-hexyl groups. Also, cyclo groups having 3 to 6 carbon atoms. Specifically, alkyl groups include cyclopropyl, cyclobutyl, and cyclopentyl groups. Examples include groups such as cyclohexyl groups. Also, aryl groups having 6 to 13 carbon atoms. Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. It can be listed.

[0229] Also, R 31 ~R 34 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon Cycloalkyl groups with 3 to 6 prime numbers, and substituted or unsubstituted aryl groups with 6 to 13 carbon atoms. It represents either a cyano group or a C1-C6 alkyl group. Specifically, C1-C6 alkyl groups include: Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert Examples include butyl groups and n-hexyl groups. Also, cyclo groups having 3 to 6 carbon atoms. Specifically, alkyl groups include cyclopropyl, cyclobutyl, and cyclopentyl groups. Examples include groups such as cyclohexyl groups. Also, aryl groups having 6 to 13 carbon atoms. Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. It can be listed. Furthermore, R 31 ~R 34 The fact that they are all hydrogen makes synthesis easy. It is also advantageous in terms of raw material prices.

[0230] Also, R 35 These are hydrogen, C1-C6 alkyl groups, and C1-C6 haloalkyl groups. Represents either a group, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Examples of alkyl groups with a number of 1 to 6 include methyl, ethyl, propyl, and isopodium groups. Examples include ropyl groups, butyl groups, isobutyl groups, tert-butyl groups, and n-hexyl groups. It is possible. Also, as a haloalkyl group having 1 to 6 carbon atoms, at least one water Alkyl sulfites are substituted with Group 17 elements (fluorine, chlorine, bromine, iodine, astatine). Kill groups include alkyl fluorides, alkyl chlorides, alkyl bromides, and alkyl iodides. Examples include groups such as methyl fluoride group, methyl chloride group, ethyl fluoride group, and chloride Examples include ethyl groups, but the number or type of halogen elements included varies. It may be one or more. Also, as an aryl group having 6 to 13 carbon atoms, Examples include the phenyl group, naphthyl group, biphenyl group, and fluorenyl group. It is possible. Furthermore, the aryl group may have substituents, and these substituents may be bonded to each other. A ring may be formed. The substituent may be an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 carbon atoms. A cycloalkyl group with 6 to 6 carbon atoms, or an aryl group with 6 to 13 carbon atoms, can also be selected as a substituent. This is possible. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl groups and ethyl groups. propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hex Examples include xyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms include... Specifically, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group Examples include the phenyl group. Specific examples include naphthyl groups, biphenyl groups, and fluorenyl groups.

[0231] Also, Ar 11 and R 31 ~R 35 The aryl group represented by, and R 31 ~R 34 few At least one of them has a cyano group.

[0232] Furthermore, in an iridium complex that can be suitably used in a light-emitting element according to one aspect of the present invention It has a high triplet excitation energy level due to having an imidazole skeleton as a ligand. It can be used in light-emitting devices that emit high-energy light, such as blue light. This is preferable because it allows for this. The iridium complex described above is represented by the following general formula (G14). It is an iridium complex.

[0233] [ka]

[0234] In the above general formula (G14), Ar 11 This refers to substituted or unsubstituted carbon atoms with 6 to 13 carbon atoms. This represents an aryl group. Examples of aryl groups with 6 to 13 carbon atoms include the phenyl group, the naphthyl group, Biphenyl groups and fluorenyl groups can be given as specific examples. If it has substituents, such substituents may be C1 to C6 alkyl groups, C3 alkyl groups, etc. Cycloalkyl groups up to 6 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 13 carbon atoms. They can be selected as substituents. Specifically, alkyl groups having 1 to 6 carbon atoms include: Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert Examples include butyl groups and n-hexyl groups. Also, cyclo groups having 3 to 6 carbon atoms. Specifically, alkyl groups include cyclopropyl, cyclobutyl, and cyclopentyl groups. Examples include groups such as cyclohexyl groups. Also, aryl groups having 6 to 13 carbon atoms. Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. It can be listed.

[0235] Also, R 31 ~R 34 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon Cycloalkyl groups with 3 to 6 prime atoms, or substituted or unsubstituted ali groups with 6 to 13 carbon atoms. It represents any of the alkyl groups. Specifically, alkyl groups having 1 to 6 carbon atoms include the methyl group, Ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group Examples include n-hexyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms. Specifically, these include cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclo Examples include hexyl groups. Also, as for aryl groups having 6 to 13 carbon atoms, Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. This is possible. Note that R 31 ~R 34 The fact that it is all hydrogen makes it easy to synthesize and inexpensive to use as raw material. It has an advantage in terms of status.

[0236] Also, R 35 and R 36 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon Haloalkyl groups with 1 to 6 prime atoms, or substituted or unsubstituted Alys with 6 to 13 carbon atoms. It represents one of the C1 to C6 alkyl groups. Specifically, alkyl groups include methyl groups and E1. Tyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, Examples include n-hexyl groups. Also, haloalkyl groups having 1 to 6 carbon atoms, Therefore, at least one hydrogen atom is a Group 17 element (fluorine, chlorine, bromine, iodine, astaxanthin) Alkyl alkyl groups substituted with (n), including alkyl fluorides, alkyl chlorides, and bromides. Examples include alkyl groups and alkyl iodides, specifically methyl fluoride groups and methyl chloride groups. Examples include ethyl fluoride groups, ethyl chloride groups, etc., but the halogen elements contained may vary. The number or type of prime elements may be one or multiple. Also, the number of carbon atoms may be 6 to 1. Examples of aryl groups in category 3 include phenyl, naphthyl, biphenyl, and fluorenyl groups. This can be given as a specific example. Furthermore, the aryl group may have substituents. Furthermore, the substituents may be bonded to each other to form a ring. The substituents may include those having 1 carbon atom. Alkyl groups up to 6 carbon atoms, cycloalkyl groups with 3 to 6 carbon atoms, or aryl groups with 6 to 13 carbon atoms. A C1-C6 alkyl group can also be selected as a substituent. Specific examples of alkyl groups include... In general, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, Examples include tert-butyl groups and n-hexyl groups. Also, groups with 3 to 6 carbon atoms. Specifically, examples of cycloalkyl groups include cyclopropyl group, cyclobutyl group, and cyclopropyl group. Examples include ethyl groups and cyclohexyl groups. Also, aryl groups with 6 to 13 carbon atoms. Examples of fluorine groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. This can be cited as an example.

[0237] Also, Ar 11 and R 31 ~R 36 The aryl group represented by R 31 ~R 34 at least Another has a cyano group.

[0238] Furthermore, in an iridium complex that can be suitably used in a light-emitting element according to one aspect of the present invention The aryl group bonded to the nitrogen in the nitrogen-containing five-membered heterocyclic skeleton is either substituted or unsubstituted phenyl As a base, vacuum deposition can be performed at relatively low temperatures, and the triplet excitation energy level is high. Therefore, it can be suitably used in light-emitting elements that exhibit high-energy light, such as blue light. The iridium complex described above is represented by the following general formulas (G15) and (G16). It is a um complex.

[0239] [ka]

[0240] In the above general formula (G15), R 37 and R 41 This is an alkyl group having 1 to 6 carbon atoms. Represented by R 37 and R 41 They have the same structure as each other. As alkyl groups having 1 to 6 carbon atoms Specifically, these include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group. Examples include the tert-butyl group, n-hexyl group, etc.

[0241] Also, R 38 ~R 40 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon A cycloalkyl group with prime numbers 3 to 6, a substituted or unsubstituted phenyl group, or a cyano group. It represents one of the following. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl groups and ethyl groups. propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hex Examples include xyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms, Specifically, these are cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl Examples include the base. 38 ~R 40 At least one of them has a cyano group It is preferable to do so.

[0242] Also, R 31 ~R 34 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon Cycloalkyl groups with 3 to 6 prime atoms, or substituted or unsubstituted ali groups with 6 to 13 carbon atoms. It represents any of the alkyl groups. Specifically, alkyl groups having 1 to 6 carbon atoms include the methyl group, Ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group Examples include n-hexyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms. Specifically, these include cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclo Examples include hexyl groups. Also, as for aryl groups having 6 to 13 carbon atoms, Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. This is possible. Note that R 31 ~R 34 The fact that it is all hydrogen makes it easy to synthesize and inexpensive to use as raw material. It has an advantage in terms of status.

[0243] Also, R 35 These are hydrogen, C1-C6 alkyl groups, and C1-C6 haloalkyl groups. Represents either a group, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Examples of alkyl groups with a number of 1 to 6 include methyl, ethyl, propyl, and isopodium groups. Examples include ropyl groups, butyl groups, isobutyl groups, tert-butyl groups, and n-hexyl groups. It is possible. Also, as a haloalkyl group having 1 to 6 carbon atoms, at least one water Alkyl sulfites are substituted with Group 17 elements (fluorine, chlorine, bromine, iodine, astatine). Kill groups include alkyl fluorides, alkyl chlorides, alkyl bromides, and alkyl iodides. Examples include groups such as methyl fluoride group, methyl chloride group, ethyl fluoride group, and chloride Examples include ethyl groups, but the number or type of halogen elements included varies. It may be one or more. Also, as an aryl group having 6 to 13 carbon atoms, Examples include the phenyl group, naphthyl group, biphenyl group, and fluorenyl group. It is possible. Furthermore, the aryl group may have substituents, and these substituents may be bonded to each other. A ring may be formed. The substituent may be an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 carbon atoms. A cycloalkyl group with 6 to 6 carbon atoms, or an aryl group with 6 to 13 carbon atoms, can also be selected as a substituent. This is possible. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl groups and ethyl groups. propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hex Examples include xyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms include... Specifically, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group Examples include the phenyl group. Specific examples include naphthyl groups, biphenyl groups, and fluorenyl groups.

[0244] [ka]

[0245] In the above general formula (G16), R 37 and R 41 This is an alkyl group having 1 to 6 carbon atoms. Represented by R 37 and R 41 They have the same structure as each other. As alkyl groups having 1 to 6 carbon atoms Specifically, these include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group. Examples include the tert-butyl group, n-hexyl group, etc.

[0246] R 38 ~R 40 These are, independently, hydrogen, an alkyl group having 1 to 6 carbon atoms, and an alkyl group having 3 carbon atoms. Any of the following: cycloalkyl groups up to 6, substituted or unsubstituted phenyl groups, or cyano groups This indicates that. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, and pro groups. Pyr group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hexyl Examples include groups. Furthermore, specific examples of cycloalkyl groups having 3 to 6 carbon atoms include... In general, these include cyclopropyl groups, cyclobutyl groups, cyclopentyl groups, and cyclohexyl groups. The following can be listed. Furthermore, R 38 ~R 40 At least one of them has a cyano group. This is preferable.

[0247] Also, R 31 ~R 34 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon Cycloalkyl groups with 3 to 6 prime atoms, or substituted or unsubstituted ali groups with 6 to 13 carbon atoms. It represents any of the alkyl groups. Specifically, alkyl groups having 1 to 6 carbon atoms include the methyl group, Ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group Examples include n-hexyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms. Specifically, these include cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclo Examples include hexyl groups. Also, as for aryl groups having 6 to 13 carbon atoms, Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. This is possible. Note that R 31 ~R 34 The fact that it is all hydrogen makes it easy to synthesize and inexpensive to use as raw material. It has an advantage in terms of status.

[0248] Also, R 35 and R 36 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon Haloalkyl groups with 1 to 6 prime atoms, or substituted or unsubstituted Alys with 6 to 13 carbon atoms. It represents one of the C1 to C6 alkyl groups. Specifically, alkyl groups include methyl groups and E1. Tyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, Examples include n-hexyl groups. Also, haloalkyl groups having 1 to 6 carbon atoms, Therefore, at least one hydrogen atom is a Group 17 element (fluorine, chlorine, bromine, iodine, astaxanthin) Alkyl alkyl groups substituted with (n), including alkyl fluorides, alkyl chlorides, and bromides. Examples include alkyl groups and alkyl iodides, specifically methyl fluoride groups and methyl chloride groups. Examples include ethyl fluoride groups, ethyl chloride groups, etc., but the halogen elements contained may vary. The number or type of prime elements may be one or multiple. Also, the number of carbon atoms may be 6 to 1. Examples of aryl groups in category 3 include phenyl, naphthyl, biphenyl, and fluorenyl groups. This can be given as a specific example. Furthermore, the aryl group may have substituents. Furthermore, the substituents may be bonded to each other to form a ring. The substituents may include those having 1 carbon atom. Alkyl groups up to 6 carbon atoms, cycloalkyl groups with 3 to 6 carbon atoms, or aryl groups with 6 to 13 carbon atoms. A C1-C6 alkyl group can also be selected as a substituent. Specific examples of alkyl groups include... In general, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, Examples include tert-butyl groups and n-hexyl groups. Also, groups with 3 to 6 carbon atoms. Specifically, examples of cycloalkyl groups include cyclopropyl group, cyclobutyl group, and cyclopropyl group. Examples include ethyl groups and cyclohexyl groups. Also, aryl groups with 6 to 13 carbon atoms. Examples of fluorine groups include phenyl, naphthyl, biphenyl, and fluorenyl groups. This can be cited as an example.

[0249] Furthermore, in an iridium complex that can be suitably used in a light-emitting element according to one aspect of the present invention It has a 1H-triazole skeleton as a ligand, which gives it a high triplet excitation energy level. Because it can have positions, it is particularly useful for light-emitting elements that exhibit high-energy light such as blue light. It is preferable because it can be used suitably. The iridium complex described above has the following general formula (G17 This is an iridium complex represented by (G18).

[0250] [ka]

[0251] In the above general formula (G17), Ar 11 This refers to substituted or unsubstituted carbon atoms with 6 to 13 carbon atoms. This represents an aryl group. Examples of aryl groups with 6 to 13 carbon atoms include the phenyl group, the naphthyl group, Biphenyl groups and fluorenyl groups can be given as specific examples. If it has substituents, such substituents may be C1 to C6 alkyl groups, C3 alkyl groups, etc. Cycloalkyl groups up to 6 carbon atoms, or substituted or unsubstituted aryl groups having 6 to 13 carbon atoms. They can be selected as substituents. Specifically, alkyl groups having 1 to 6 carbon atoms include: Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert Examples include butyl groups and n-hexyl groups. Also, cyclo groups having 3 to 6 carbon atoms. Specifically, alkyl groups include cyclopropyl, cyclobutyl, and cyclopentyl groups. Examples include groups such as cyclohexyl groups. Also, aryl groups having 6 to 13 carbon atoms. Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. It can be listed.

[0252] Also, R 31 ~R 34 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon Cycloalkyl groups with 3 to 6 prime atoms, or substituted or unsubstituted ali groups with 6 to 13 carbon atoms. It represents any of the alkyl groups. Specifically, alkyl groups having 1 to 6 carbon atoms include the methyl group, Ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group Examples include n-hexyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms. Specifically, these include cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclo Examples include hexyl groups. Also, as for aryl groups having 6 to 13 carbon atoms, Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. This is possible. Note that R 31 ~R 34 The fact that it is all hydrogen makes it easy to synthesize and inexpensive to use as raw material. It has an advantage in terms of status.

[0253] Also, R 36 These are hydrogen, C1-C6 alkyl groups, and C1-C6 haloalkyl groups. Represents either a group, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Examples of alkyl groups with a number of 1 to 6 include methyl, ethyl, propyl, and isopodium groups. Examples include ropyl groups, butyl groups, isobutyl groups, tert-butyl groups, and n-hexyl groups. It is possible. Also, as a haloalkyl group having 1 to 6 carbon atoms, at least one water Alkyl sulfites are substituted with Group 17 elements (fluorine, chlorine, bromine, iodine, astatine). Kill groups include alkyl fluorides, alkyl chlorides, alkyl bromides, and alkyl iodides. Examples include groups such as methyl fluoride group, methyl chloride group, ethyl fluoride group, and chloride Examples include ethyl groups, but the number or type of halogen elements included varies. It may be one or more. Also, as an aryl group having 6 to 13 carbon atoms, Examples include the phenyl group, naphthyl group, biphenyl group, and fluorenyl group. It is possible. Furthermore, the aryl group may have substituents, and these substituents may be bonded to each other. A ring may be formed. The substituent may be an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 carbon atoms. A cycloalkyl group with 6 to 6 carbon atoms, or an aryl group with 6 to 13 carbon atoms, can also be selected as a substituent. This is possible. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl groups and ethyl groups. propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hex Examples include xyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms include... Specifically, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group Examples include the phenyl group. Specific examples include naphthyl groups, biphenyl groups, and fluorenyl groups.

[0254] Also, Ar 11 , R 31 ~R 34 , and R 36 The aryl group represented by, and R 31 ~R 34 At least one of them has a cyano group.

[0255] [ka]

[0256] In the above general formula (G18), R 37 and R 41 This is an alkyl group having 1 to 6 carbon atoms. Represented by R 37 and R 41 They have the same structure as each other. As alkyl groups having 1 to 6 carbon atoms Specifically, these include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group. Examples include the tert-butyl group, n-hexyl group, etc.

[0257] Also, R 38 ~R 40 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon A cycloalkyl group with prime numbers 3 to 6, a substituted or unsubstituted phenyl group, or a cyano group. It represents one of the following. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl groups and ethyl groups. propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hex Examples include xyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms, Specifically, these are cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclohexyl Examples include the base. 38 ~R 40 At least one of them has a cyano group It is preferable to do so.

[0258] Also, R 31 ~R 34 Each of these independently consists of hydrogen, an alkyl group having 1 to 6 carbon atoms, and carbon Cycloalkyl groups with 3 to 6 prime atoms, or substituted or unsubstituted ali groups with 6 to 13 carbon atoms. It represents any of the alkyl groups. Specifically, alkyl groups having 1 to 6 carbon atoms include the methyl group, Ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group Examples include n-hexyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms. Specifically, these include cyclopropyl group, cyclobutyl group, cyclopentyl group, and cyclo Examples include hexyl groups. Also, as for aryl groups having 6 to 13 carbon atoms, Examples include phenyl groups, naphthyl groups, biphenyl groups, and fluorenyl groups. This is possible. Note that R 31 ~R 34 The fact that it is all hydrogen makes it easy to synthesize and inexpensive to use as raw material. It has an advantage in terms of status.

[0259] Also, R 36 These are hydrogen, C1-C6 alkyl groups, and C1-C6 haloalkyl groups. Represents either a group, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Examples of alkyl groups with a number of 1 to 6 include methyl, ethyl, propyl, and isopodium groups. Examples include ropyl groups, butyl groups, isobutyl groups, tert-butyl groups, and n-hexyl groups. It is possible. Also, as a haloalkyl group having 1 to 6 carbon atoms, at least one water Alkyl sulfites are substituted with Group 17 elements (fluorine, chlorine, bromine, iodine, astatine). Kill groups include alkyl fluorides, alkyl chlorides, alkyl bromides, and alkyl iodides. Examples include groups such as methyl fluoride group, methyl chloride group, ethyl fluoride group, and chloride Examples include ethyl groups, but the number or type of halogen elements included varies. It may be one or more. Also, as an aryl group having 6 to 13 carbon atoms, Examples include the phenyl group, naphthyl group, biphenyl group, and fluorenyl group. It is possible. Furthermore, the aryl group may have substituents, and these substituents may be bonded to each other. A ring may be formed. The substituent may be an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 3 carbon atoms. A cycloalkyl group with 6 to 6 carbon atoms, or an aryl group with 6 to 13 carbon atoms, can also be selected as a substituent. This is possible. Specifically, alkyl groups having 1 to 6 carbon atoms include methyl groups and ethyl groups. propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, n-hex Examples include xyl groups. Also, cycloalkyl groups having 3 to 6 carbon atoms include... Specifically, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group Examples include the phenyl group. Specific examples include naphthyl groups, biphenyl groups, and fluorenyl groups.

[0260] R in the above general formulas (G12) to (G18) 31 ~R 34 Alkyl and The aryl group can be, for example, the group represented by the structural formulas (R-1) to (R-29) above. This is possible. The groups that can be used as alkyl and aryl groups are these. It is not limited to that.

[0261] Furthermore, in general formulas (G11) to (G14) and (G17), Ar 11 As shown The aryl group that is formed, and in general formula (G11), Ar 12 Let the aryl group be represented as For example, applying the groups represented by the above structural formulas (R-12) to (R-29) Yes, it is possible. Also, Ar 11 and Ar 12 These are not the only groups that can be used as such. .

[0262] Furthermore, the R in general formulas (G15), (G16), and (G18)37 and R 41 It is represented The alkyl group can be, for example, a group represented by the above structural formulas (R-1) to (R-10). This is possible. However, the groups that can be used as alkyl groups are not limited to these.

[0263] Furthermore, the R in general formulas (G15), (G16), and (G18) 38 ~R 40 It is represented Alkyl groups or substituted or unsubstituted phenyl groups are, for example, those in the above structural formula (R-1) to The group represented by (R-22) can be applied. Note that this may include alkyl groups or phenyl groups. These are not the only groups that can be used as such.

[0264] Furthermore, R in the above general formulas (G13) to (G16) 35 , and general formula (G14), (G1 6) R of (G18) 36 Alkyl, aryl, or haloalkyl groups represented by For example, the above structural formulas (R-1) to (R-29), and the following structural formulas (R-30) to The group represented by (R-37) can be applied. Note that alkyl groups, aryl groups, and The groups that can be used as haloalkyl groups are not limited to these.

[0265] [ka]

[0266] ≪Specific examples of iridium complexes≫ The specific structures of the iridium complexes represented by the above general formulas (G11) to (G18) and Examples include compounds represented by the following structural formulas (500) to (534). iridium complexes represented by general formulas (G11) to (G18) are not limited to the examples shown below. stomach.

[0267] [ka]

[0268] [ka]

[0269] [ka]

[0270] [ka]

[0271] [ka]

[0272] [ka]

[0273] As described above, the iridium complexes exemplified above have relatively low HOMO levels and LU levels. Because it has an MO level, it is suitable as a guest material for a light-emitting element according to one embodiment of the present invention. This makes it possible to create light-emitting elements with good luminescence efficiency. Iridium complexes have high triplet excitation energy levels, and are particularly blue light-emitting elements. This is suitable as a guest material for this product. This allows for the fabrication of a blue light-emitting element with good luminescence efficiency. It is possible to do so. Furthermore, the iridium complexes exemplified above are suitable for repeated oxidation and reduction. Because it has good resistance, using this iridium complex in a light-emitting element improves the operating life. A good light-emitting element can be fabricated.

[0274] Furthermore, the light-emitting material contained in the light-emitting layer 130 and the light-emitting layer 135 is a triplet excitation energy Any material that can convert energy into light emission is acceptable. In addition to phosphorescent materials, thermally activated delayed fluorescence materials can also be used as materials. Where the term "optical material" is used, it may be interpreted as "thermally activated delayed fluorescence material."

[0275] ≪Host Material 133≫ As for host material 133, a LUMO level higher than the LUMO level of host material 132 is The host material has a HOMO level lower than the HOMO level of the host material 132. It is preferable to select 133 and host material 132. This results in high luminescence efficiency. This allows for a light-emitting element that can be driven at a low voltage. Furthermore, the host material 133 is... The material exemplified as material 132 may also be used.

[0276] As the host material 133, a material with higher electron transport capabilities than hole transport can be used. 1 x 10 -6 cm 2 It is preferable that the material has an electron mobility of / Vs or higher. Materials that readily accept electrons (materials with electron transport properties) include nitrogen-containing heteroaromatic compounds. Compounds having a π-electron-deficient heteroaromatic ring skeleton, and zinc and aluminum-based metal complexes. These can be used. Specifically, quinoline ligands, benzoquinoline ligands, oxa Metal complexes having a zole ligand or a thiazole ligand, or oxadiazole derivatives , triazole derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinone Xaline derivatives, phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, pyrimi Examples include compounds such as din derivatives and triazine derivatives.

[0277] Specifically, for example, tris(8-quinolinolato)aluminum(III) (abbreviation: A lq), Tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Al mq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) (abbreviation) :BeBq2), bis(2-methyl-8-quinolinolate)(4-phenylphenolate) Luminium(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (abbreviation) Examples include metal complexes having a quinoline skeleton or a benzoquinoline skeleton, such as Znq. In addition, bis[2-(2-benzoxazolyl)phenolate]zinc(II) Abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolate]zinc(II) Metal complexes having oxazole or thiazole ligands, such as (abbreviated as ZnBTZ) Others can also be used. Furthermore, in addition to metal complexes, 2-(4-biphenylyl)-5 -(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD) or, 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazo [Il-2-yl]benzene (abbreviation: OXD-7), 9-[4-(5-phenyl-1,3, 4-Oxadiazole-2-yl)phenyl]-9H-carbazole (abbreviation: CO11) , 3-(4-biphenylyl)-4-phenyl-5-(4-tert-butylphenyl)- 1,2,4-Triazole (abbreviation: TAZ), 9-[4-(4,5-diphenyl-4H- 1,2,4-Triazole-3-yl)phenyl]-9H-carbazole (abbreviation: CzT) AZ1), 2,2',2''-(1,3,5-benzenetriyl)tris(1-phenyl -1H-benzimidazole) (abbreviation: TPBI), 2-[3-(dibenzothiophene- 4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviation: mDBTBI) m-II), vasophenanthroline (abbreviation: BPhen), vasocuproin (abbreviation: B Heterocyclic compounds such as CP, and 2-[3-(dibenzothiophen-4-yl)phenyl] Dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-( [Dibenzothiophen-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxali (Abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-I [biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDB) q) 2-[4-(3,6-diphenyl-9H-carbazole-9-yl)phenyl]di Benzo[f,h]quinoxaline (abbreviation: 2CzPDBq-III), 7-[3-(dibenz[f,h]quinoxaline) Zothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 7mDB) TPDBq-II), and 6-[3-(dibenzothiophen-4-yl)phenyl]di Benzo[f,h]quinoxaline (abbreviation: 6mDBTPDBq-II), 2-[3-(3, 9'-bi-9H-carbazole-9-yl)phenyl]dibenzo[f,h]quinoxaline (Abbreviation: 2mCzCzPDBq), 4,6-bis[3-(phenanthrene-9-yl)f [enyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-diben Zothienyl phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II), 4,6- Bis[3-(9H-carbazole-9-yl)phenyl]pyrimidine (abbreviation: 4,6mC) Heterocyclic compounds having a diazine skeleton such as zP2Pm, and 2-{4-[3-(N-Fe)}. Nyl-9H-carbazole-3-yl)-9H-carbazole-9-yl]phenyl}- Triazines such as 4,6-diphenyl-1,3,5-triazine (abbreviation: PCCzPTzn) Heterocyclic compounds having a din skeleton, or 3,5-bis[3-(9H-carbazole-9-yl] )phenyl]pyridine (abbreviation: 35DCzPPy), 1,3,5-tri[3-(3-pyridine) Heterocyclization of pyridine skeletons such as [zyl]phenyl]benzene (abbreviation: TmPyPB) Compound, 4,4'-bis(5-methylbenzoxazole-2-yl)stilbene (abbreviation: Heteroaromatic compounds such as BzOs can also be used. Among the heterocyclic compounds mentioned above... Also, triazine skeleton, diazine (pyrimidine, pyrazine, pyridazine) skeleton, or pyr Heterocyclic compounds having a din skeleton are stable, reliable, and therefore preferable. Heterocyclic compounds containing have high electron transport properties and contribute to reducing the driving voltage. Also, poly( 2,5-Pyridinediyl) (abbreviation: PPy), poly[(9,9-dihexylfluorene- 2,7-diyl)-co-(pyridine-3,5-diyl) (abbreviation: PF-Py), poly [(9,9-dioctylfluorene-2,7-diyl)-co-(2,2'-bipyridine) It is also possible to use polymer compounds such as (-6,6'-diyl) (abbreviation: PF-BPy). The substances described here are mainly 1 × 10 -6 cm 2 Objects with electron mobility of / Vs or greater It is a matter of quality. Furthermore, if the material has higher electron transport capabilities than holes, other materials can be used. That's fine too.

[0278] Furthermore, the following hole-transporting materials can be used as the host material 133.

[0279] As a hole-transporting material, a material with higher hole transport capabilities than electron transport can be used, ×10 -6 cm 2 It is preferable that the material has a hole mobility of / Vs or greater. Specifically This uses aromatic amines, carbazole derivatives, aromatic hydrocarbons, stilbene derivatives, etc. This is possible. Furthermore, the hole-transporting material may be a polymer compound.

[0280] These materials with high hole transport capabilities include, specifically, aromatic amine compounds such as N, N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DT) DPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenyl Mino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl [amino]phenyl]-N,N'-diphenyl-(1,1'-biphenyl)-4,4' -Diamine (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophen) Examples include [phenyl]-N-phenylaminobenzene (abbreviation: DPA3B), etc. .

[0281] Furthermore, as a carbazole derivative, specifically, 3-[N-(4-diphenylamino Phenyl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzDPA1) ), 3,6-bis[N-(4-diphenylaminophenyl)-N-phenylamino]-9 -Phenylcarbazole (abbreviation: PCzDPA2), 3,6-bis[N-(4-diphenyl (Aminophenyl)-N-(1-naphthyl)amino]-9-phenylcarbazole (abbreviation) :PCzTPN2), 3-[N-(9-phenylcarbazole-3-yl)-N-phenyl Luamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N- (9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarb Zol (abbreviation: PCzPCA2), 3-[N-(1-naphthyl)-N-(9-phenylcate Luvazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1) Examples include:

[0282] In addition, other carbazole derivatives include 4,4'-di(N-carbazolyl)bife Nyl (abbreviated as CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]bene Zen (abbreviation: TCPB), 9-[4-(10-phenyl-9-antryl)phenyl]- 9H-carbazole (abbreviation: CzPA), 1,4-bis[4-(N-carbazolyl)phen [Nyl]-2,3,5,6-tetraphenylbenzene, etc., can be used.

[0283] Furthermore, examples of aromatic hydrocarbons include 2-tert-butyl-9,10-di(2- Naphthyl)anthracene (abbreviation: t-BuDNA), 2-tert-butyl-9,10- Di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene Tracene (abbreviation: DPPA), 2-tert-butyl-9,10-bis(4-phenyl Enyl anthracene (abbreviation: t-BuDBA), 9,10-di(2-naphthyl)ant Helical (abbreviated as DNA), 9,10-diphenylanthracene (abbreviated as DPaNth), 2-tert-butylanthracene (abbreviation: t-BuAnth), 9,10-bis(4- Methyl-1-naphthyl)anthracene (abbreviation: DMNA), 2-tert-butyl-9, 10-Bis[2-(1-naphthyl)phenyl]anthracene, 9,10-Bis[2-(1 -Naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di( 1-Naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl) Chil)anthracene, 9,9'-bianthryl, 10,10'-diphenyl-9,9'- Biantryl, 10,10'-bis(2-phenylphenyl)-9,9'-biantryl ,10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9' -Biantril, Anthracene, Tetracene, Rubren, Perylene, 2, 5, 8, 11- Examples include tetra(tert-butyl)perylene. In addition, pentacene, coro Nen and other similar materials can also be used. In this way, 1 × 10 -6 cm 2 Hole mobility of / Vs or greater It is more preferable to use aromatic hydrocarbons having 14 to 42 carbon atoms.

[0284] Furthermore, aromatic hydrocarbons may have a vinyl skeleton. Examples of group hydrocarbons include 4,4'-bis(2,2-diphenylvinyl)biphenyl (Abbreviation: DPVBi), 9,10-bis[4-(2,2-diphenylvinyl)phenyl] Examples include anthracene (abbreviated as DPVPA).

[0285] Also, poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphen Nylamine (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenyl [amino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide]( Abbreviation: PTPDMA), poly[N,N'-bis(4-butylphenyl)-N,N'-bis High molecular weight compounds such as (phenyl)benzidine (abbreviated as Poly-TPD) can also be used. can.

[0286] Furthermore, as a material with high hole transport properties, for example, 4,4'-bis[N-(1-naphthium [N-phenylamino]biphenyl (abbreviated as NPB or α-NPD) or N,N'- Bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4, 4'-Diamine (abbreviation: TPD), 4,4',4''-Tris(carbazole-9-yl) ) Triphenylamine (abbreviation: TCTA), 4,4',4''-tris[N-(1-naphtholamine) [1'-TNATA]-N-phenylaminotriphenylamine (abbreviation: 1'-TNATA), 4,4 ',4''-Tris(N,N-diphenylamino)triphenylamine (abbreviation: TDAT) A) 4,4',4''-Tris[N-(3-methylphenyl)-N-phenylamino] Triphenylamine (abbreviation: MTDATA), 4,4'-bis[N-(spiro-9,9' -bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4 -phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)trife Nylamine (abbreviation: mBPAFLP), N-(9,9-dimethyl-9H-fluorene-2) -yl)-N-{9,9-dimethyl-2-[N'-phenyl-N'-(9,9-dimethyl -9H-fluoren-2-yl)amino]-9H-fluoren-7-yl}phenylamine N (abbreviation: DFLADFL), N-(9,9-dimethyl-2-diphenylamino-9H- Fluoren-7-yl)diphenylamine (abbreviation: DPNF), 2-[N-(4-diphenyl [Nylaminophenyl)-N-phenylamino]spiro-9,9'-bifluorene (abbreviation: DPASF), 4-phenyl-4'-(9-phenyl-9H-carbazole-3-yl) Triphenylamine (abbreviation: PCBA1BP), 4,4'-diphenyl-4''-(9- Phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBBi1B) P), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl) Triphenylamine (abbreviation: PCBANB), 4,4'-di(1-naphthyl)-4''- (9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBN) BB), 4-phenyldiphenyl-(9-phenyl-9H-carbazole-3-yl) Min (abbreviation: PCA1BP), N,N'-bis(9-phenylcarbazole-3-yl) -N,N'-diphenylbenzene-1,3-diamine (abbreviation: PCA2B), N,N', N''-triphenyl-N,N',N''-tris(9-phenylcarbazole-3-I) (L)Benzene-1,3,5-triamine (abbreviation: PCA3B), N-(4-biphenyl) -N-(9,9-dimethyl-9H-fluoren-2-yl)-9-phenyl-9H-cal Bazole-3-amine (abbreviation: PCBiF), N-(1,1'-biphenyl-4-yl) -N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9,9-di Methyl-9H-fluoren-2-amine (abbreviation: PCBBiF), 9,9-dimethyl-N -phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl] Luolen-2-amine (abbreviation: PCBAF), N-phenyl-N-[4-(9-phenyl -9H-carbazole-3-yl)phenyl]spiro-9,9'-bifluoren-2-a Min (abbreviation: PCBASF), 2-[N-(9-phenylcarbazole-3-yl)-N -phenylamino]spiro-9,9'-bifluorene (abbreviation: PCASF), 2,7-bi S[N-(4-diphenylaminophenyl)-N-phenylamino]spiro-9,9'- Bifluoren (abbreviation: DPA2SF), N-[4-(9H-carbazole-9-yl) [phenyl]-N-(4-phenyl)phenylaniline (abbreviation: YGA1BP), N,N'- Bis[4-(carbazole-9-yl)phenyl]-N,N'-diphenyl-9,9-di Aromatic amine compounds such as methylfluorene-2,7-diamine (abbreviation: YGA2F), etc. It can also be used. Furthermore, 3-[4-(1-naphthyl)-phenyl]-9-phenyl -9H-carbazole (abbreviation: PCPN), 3-[4-(9-phenanthril)-pheni [Lu]-9-phenyl-9H-carbazole (abbreviation: PCPPn), 3,3'-bis(9- Phenyl-9H-carbazole (abbreviation: PCCP), 1,3-bis(N-carbazolyl) )Benzene (abbreviation: mCP), 3,6-bis(3,5-diphenylphenyl)-9-phenyl Nilcarbazole (abbreviation: CzTP), 3,6-di(9H-carbazole-9-yl)- 9-phenyl-9H-carbazole (abbreviation: PhCzGI), 2,8-di(9H-carbazole) Zole-9-yl)-dibenzothiophene (abbreviation: Cz2DBT), 4-{3-[3-( 9-phenyl-9H-fluoren-9-yl)phenyl]phenyl}dibenzofuran (abbreviated) Name: mmDBFFLBi-II), 4,4',4''-(benzene-1,3,5-torii 1,3,5-tri(dibenzofuran) (abbreviation: DBF3P-II), 1,3,5-tri(dibenzofuran) Thiophen-4-yl)benzene (abbreviation: DBT3P-II), 2,8-diphenyl-4 -[4-(9-phenyl-9H-fluoren-9-yl)phenyl]dibenzothiophene (Abbreviation: DBTFLP-III), 4-[4-(9-phenyl-9H-fluorene-9- [Iyl)phenyl]-6-phenyldibenzothiophene (abbreviation: DBTFLP-IV), 4 -[3-(triphenylene-2-yl)phenyl]dibenzothiophene (abbreviation: mDBT) Amine compounds such as PTp-II, carbazole compounds, thiophene compounds, and furan compounds The following can be used: substances, fluorene compounds, triphenylene compounds, phenanthrene compounds, etc. Yes, it is possible. Among the compounds mentioned above, the pyrrole skeleton, furan skeleton, thiophene skeleton, or Compounds having an aromatic amine skeleton are preferred because they are stable and reliable. Compounds with a specific property exhibit high hole transport properties and contribute to reducing the driving voltage.

[0287] Furthermore, the light-emitting layer 130 and the light-emitting layer 135 can also be composed of two or more layers. For example, the first light-emitting layer and the second light-emitting layer are stacked in order from the hole transport layer side to form a light-emitting layer 13 When 0 or the light-emitting layer 135 is used, the host material of the first light-emitting layer has hole transport properties. This configuration uses materials, and includes using a material with electron transport properties as the host material for the second light-emitting layer. Furthermore, even if the light-emitting material of the first light-emitting layer and the second light-emitting layer is the same material, Even if they are different materials, even if they are materials that have the function of emitting light of the same color, The material may also have the function of emitting light of a color. Two light-emitting layers of different colors By using different light-emitting materials that have the function of emitting light, multiple light sources can be obtained simultaneously. This is possible. In particular, the light emitted by the two light-emitting layers is used in each light-emitting layer so that it becomes white. It is preferable to select a light-emitting material.

[0288] Furthermore, in the light-emitting layer 130, materials other than the host material 132 and the guest material 131 are used. It may also be present. In addition, in the light-emitting layer 135, host material 133, host material 132 It may also have materials other than guest material 131.

[0289] Furthermore, the light-emitting layer 130 and the light-emitting layer 135 are produced by vapor deposition (including vacuum deposition) and inkjet. It can be formed by methods such as the printing method, coating method, and gravure printing. In addition to the materials mentioned above... , inorganic compounds or polymer compounds such as quantum dots (oligomers, dendrimers, polymers) It may have (etc.).

[0290] Quantum dots include colloidal quantum dots, alloy quantum dots, and core-shell quantum dots. You may also use type quantum dots, core quantum dots, etc. Also, groups 2, 16, and 13 Includes element groups of Group 15, Groups 13 and 17, Groups 11 and 17, or Groups 14 and 15. Quantum dots may be used. Alternatively, cadmium (Cd), selenium (Se), zinc (Zn) may be used. ), sulfur (S), phosphorus (P), indium (In), tellurium (Te), lead (Pb), gallium Quantum dots containing elements such as um (Ga), arsenic (As), and aluminum (Al) are used. It's okay to be there.

[0291] ≪Hole Injection Layer≫ The hole injection layer 111 is a hole injection layer that receives holes from one of the pair of electrodes (electrode 101 or electrode 102). It has the function of promoting hole injection by reducing the injection barrier, for example, transition metal oxides, f It is formed by tarocyanine derivatives or aromatic amines, etc. Transition metal oxides and For example, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide Examples include manganese oxides. Phthalocyanine derivatives include phthalocyanine and Examples include metal phthalocyanines. Aromatic amines include benzidine derivatives and phenyl Examples include lendiamine derivatives. Polymer compounds such as polythiophene and polyaniline. It is also possible to use substances, for example, self-doped polythiophenes such as poly(ethylenedi(ethylenedi) Typical examples include oxythiophene / poly(styrene sulfonic acid).

[0292] As the hole injection layer 111, a hole transport material and a material that exhibits electron-accepting properties in relation to it are combined. A layer containing composite material can also be used. Alternatively, a layer containing an electron-accepting material and a positive A lamination of layers containing pore-transporting material may also be used. Between these materials, a steady state or electrical current may be maintained. Charge transfer is possible in the presence of an electron barrier. Examples of materials exhibiting electron-accepting properties include Kinojimeta. Organic acceptors such as chloranil derivatives and hexaazatriphenylene derivatives We can list the following: Specifically, 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-Hexazatriphenylene (abbreviated) These are compounds that have electron-withdrawing groups (halogen groups or cyano groups), such as HAT-CN. Furthermore, transition metal oxides, such as oxides of Group 4 to Group 8 metals, can be used. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, acid These include tungsten oxide, manganese oxide, and rhenium oxide. Among these, molybdenum oxide is particularly toxic to the atmosphere. Among them, it is preferable because it is stable, has low hygroscopicity, and is easy to handle.

[0293] As a hole-transporting material, a material with higher hole transport capabilities than electron transport can be used, ×10 -6 cm 2 It is preferable that the material has a hole mobility of / Vs or greater. Specifically Aromatic amines and carbazoles were listed as hole transport materials that can be used in the light-emitting layer. A nitrite derivative, aromatic hydrocarbon, stilbene derivative, etc., can be used. The transportable material may be a polymer compound.

[0294] ≪Hole transport layer≫ The hole transport layer 112 is a layer containing a hole transportable material, and is an example of the material used for the hole injection layer 111. The hole transport material shown can be used. The hole transport layer 112 is in the hole injection layer 111. Because it has the function of transporting the injected holes to the light-emitting layer, the hole injection layer 111 has the highest occupied orbital. (Highest Occupied Molecular Orbital, HOMO It is preferable to have the same or close HOMO level as the level (also known as the HOMO level).

[0295] Also, 1 x 10 -6 cm 2 It is preferable that the substance has a hole mobility of / Vs or higher. However, other materials may be used as long as they have higher hole transport capabilities than electron transport. Furthermore, the layer containing the material with high hole transport properties may be a single layer, or a double layer consisting of the aforementioned material. You may stack more than this amount.

[0296] ≪Electron transport layer≫ The electron transport layer 118 passes through the electron injection layer 119 to the other of the pair of electrodes (electrode 101 or electron It has the function of transporting electrons injected from pole 102) to the light-emitting layer. This allows the use of materials with higher electron transport capabilities than holes, resulting in 1 × 10⁻⁶ -6 cm 2 / Vs It is preferable that the material has the above electron mobility. Compounds that readily accept electrons (electron Examples of materials with electron transport properties include π-electron-deficient heteroaromatic compounds such as nitrogen-containing heteroaromatic compounds. Aromatic compounds and metal complexes can be used. Specifically, the electric group that can be used in the light-emitting layer The materials listed as transportable materials are quinoline ligands, benzoquinoline ligands, and oxazole ligands. , or metal complexes having thiazole ligands, oxadiazole derivatives, triazoles Derivatives, benzimidazole derivatives, quinoxaline derivatives, dibenzoquinoxaline derivatives phenanthroline derivatives, pyridine derivatives, bipyridine derivatives, pyrimidine derivatives, Examples include riazine derivatives. Also, 1 × 10 -6 cm 2 Electron mobility of / Vs or higher It is preferable that the material has [a certain property]. Furthermore, any material that has higher electron transport capabilities than holes is preferable. Other materials may be used as the electron transport layer. Also, the electron transport layer 118 is a single layer. Furthermore, two or more layers made of the above-mentioned material may be stacked.

[0297] Furthermore, even if a layer for controlling the movement of electron carriers is provided between the electron transport layer 118 and the light-emitting layer, Good. The layer that controls the movement of electron carriers is made of a material with high electron transport properties as described above. A layer to which a small amount of a highly trapping substance is added, thereby suppressing the movement of electron carriers. Therefore, it becomes possible to adjust the carrier balance. In this configuration, the light-emitting layer is electrically... This significantly reduces problems caused by the child protruding (for example, a decrease in the lifespan of the element). It will be effective.

[0298] ≪Electron injection layer≫ The electron injection layer 119 promotes electron injection by reducing the electron injection barrier from the electrode 102. It has the function of being, for example, Group 1 metals, Group 2 metals, or their oxides and halides. Carbonates and the like can be used. In addition, the electron transport material shown above and the electron transport material therefor Composite materials exhibiting electron-donating properties can also be used. Examples of electron-donating materials include: Examples include Group 1 metals, Group 2 metals, or oxides thereof. Specifically These are lithium fluoride (LiF), sodium fluoride (NaF), and cesium fluoride (CsF). ), calcium fluoride (CaF2), lithium oxide (LiO2) x ) and other alkali metals Alkaline earth metals, or compounds thereof can be used. Also, fluoride Rare earth metal compounds such as bium (ErF3) can be used. Furthermore, electron injection layers can be used. An electride may be used in 119. For example, calcium Examples include substances obtained by adding a high concentration of electrons to a mixed oxide of aluminum and luminum. The injection layer 119 may be made of a material that can be used in the electron transport layer 118.

[0299] Furthermore, the electron injection layer 119 is a composite made by mixing an organic compound and an electron donor. Materials may be used. Such composite materials are created when electrons are released from the organic compound by an electron donor. Therefore, it exhibits excellent electron injection and electron transport properties. In this case, as an organic compound... Preferably, the material is one that is excellent at transporting the generated electrons, specifically, for example, the material described above. The electron transport layer 118 can be composed of materials (such as metal complexes or heteroaromatic compounds). The electron donor can be any substance that exhibits electron-donating properties towards organic compounds. Alkali metals, alkaline earth metals, and rare earth metals are preferred, as are lithium and sodium. Examples include cesium, magnesium, calcium, erbium, and ytterbium. Furthermore, alkali metal oxides and alkaline earth metal oxides are preferred, as are lithium oxides and calcium oxides. Examples include sium oxide and barium oxide. Also, Lewis plates such as magnesium oxide. Bases can also be used. Additionally, organic compounds such as tetrathiafulvalene (abbreviated as TTF) can be used. Objects can also be used.

[0300] Furthermore, the above-mentioned light-emitting layer, hole injection layer, hole transport layer, electron transport layer, and electron injection layer are, These methods include vapor deposition (including vacuum deposition), inkjet printing, coating, and gravure printing. It can be formed by the above-mentioned method. In addition, the light-emitting layer, hole injection layer, hole transport layer, electron In addition to the materials mentioned above, the transport layer and electron injection layer also contain inorganic compounds such as quantum dots and high-molecular-weight materials. Sub-compounds (oligomers, dendrimers, polymers, etc.) may also be used.

[0301] ≪A pair of electrodes≫ Electrodes 101 and 102 function as the anode or cathode of the light-emitting element. 101 and electrode 102 are made of metals, alloys, conductive compounds, and mixtures or laminates thereof. It can be formed using [a specific method / tool].

[0302] Either electrode 101 or electrode 102 is formed by a conductive material having the function of reflecting light. Preferably, this is done. The conductive material is aluminum (Al) or an Al-containing alloy. Examples include gold. Alloys containing Al include Al and L (where L is titanium (Ti) and neodymium). Includes (one or more of Nd, Ni, and La) Examples include alloys containing Al and Ti, or Al, Ni, and La. Aluminum has low resistance and high light reflectivity. Also, aluminum is found in the Earth's crust. Because it is abundant and inexpensive, using aluminum reduces the cost of manufacturing light-emitting devices. It can reduce the amount of silver (Ag), or Ag and N (N is yttrium). Y), Nd, Magnesium (Mg), Ytterbium (Yb), Al, Ti, Gallium ( Ga), zinc (Zn), indium (In), tungsten (W), manganese (Mn), Tin (Sn), iron (Fe), nickel, copper (Cu), palladium (Pd), iridium (Ir ), or alloys containing one or more gold (Au) may be used. Examples of alloys include alloys containing silver, palladium, and copper, alloys containing silver and copper, and alloys containing silver and magnesium. Alloys containing nesium, alloys containing silver and nickel, alloys containing silver and gold, and alloys containing silver and ytterbium Examples include alloys containing tungsten, chromium (Cr), and molybdenum (Mo). ), transition metals such as copper and titanium can be used.

[0303] Furthermore, the light emitted from the light-emitting layer passes through one or both of electrodes 101 and 102. And it is removed. Therefore, at least one of electrode 101 and electrode 102 transmits light. Preferably, it is formed from a conductive material having the function of being visible. The light transmittance is 40% or more and 100% or less, preferably 60% or more and 100% or less, and That resistivity is 1 × 10⁻⁶ -2 Examples include conductive materials with a conductivity of Ω·cm or less.

[0304] Furthermore, electrodes 101 and 102 have the function of transmitting light and the function of reflecting light. It may be formed from a conductive material having a visible light reflectance of 20. The resistivity is between % and 80%, preferably between 40% and 70%, and its resistivity is 1 × 10⁻⁶. -2 Examples of conductive materials include those with a conductivity of Ω·cm or less. For example, conductive metals, alloys, and conductive materials. It can be formed using one or more types of chemical compounds. Specifically, for example, Indium tin oxide (ITO), silicon, or silicon oxide Indium tin oxide (abbreviated as ITSO), indium oxide-zinc oxide (Indi Indium-tin oxide containing titanium (indium zinc oxide), indium Metals such as indium oxide containing titanium oxide, tungsten oxide, and zinc oxide. Oxides can be used. Also, the degree to which light is transmitted (preferably 1 nm to 30 nm) A thin metal film with a thickness of m or less can be used. Examples of metals include Ag, or Alloys such as Ag and Al, Ag and Mg, Ag and Au, and Ag and Yb can be used.

[0305] In this specification, etc., a material having the function of transmitting light is defined as a material having the function of transmitting visible light. Any material that has and is conductive is acceptable, for example, ITO as described above. In addition to oxide conductors, the collection includes oxide semiconductors or organic conductors containing organic materials. Examples of organic conductors include those obtained by mixing an organic compound with an electron donor. Examples include composite materials, such as composite materials formed by mixing organic compounds with electron acceptors. It is possible to use inorganic carbon-based materials such as graphene. Preferably, the ratio is 1 × 10⁻⁶. 5 Ω·cm or less, more preferably 1 × 10⁻⁶ 4 Ω·cm The following applies:

[0306] Furthermore, by stacking multiple of the above materials, one of the electrodes 101 and 102 can be made They may form both.

[0307] Furthermore, in order to improve the light extraction efficiency, the electrode having a light-transmitting function is brought into contact with the A material with a refractive index higher than that of the electrode may be formed. Such a material may transmit visible light. Any material that has the function of being conductive is acceptable, and even if it is a conductive material, it does not have that function. Other options include oxide conductors, oxide semiconductors, and organic materials. Examples of organic materials include the light-emitting layer, hole injection layer, hole transport layer, electron transport layer, or electric Examples of materials used in the sub-injection layer include those shown in the example. Also, inorganic carbon-based materials and thin films that allow light to pass through are also examples. These metals can also be used. Using these materials with high refractive indices, several nanometers to tens of nanometers Multiple layers may be stacked.

[0308] When electrode 101 or electrode 102 functions as a cathode, the work function is small. It is preferable that the material has a (3.8 eV or less) energy. For example, it is preferable that it has elements from Group 1 or Group 2 of the periodic table. Elements belonging to the group (alkali metals such as lithium, sodium, and cesium, calcium, stoichiometric compounds) Alkaline earth metals such as rontium, magnesium, etc., and alloys containing these elements (for example, Rare earth metals such as Ag and Mg, Al and Li, europium (Eu), Yb, and these rare earths Metal alloys, aluminum alloys, silver alloys, etc., can be used.

[0309] Furthermore, when electrode 101 or electrode 102 is used as the anode, the work function is large (4. It is preferable to use a material with a voltage of 0 eV or higher.

[0310] Furthermore, electrodes 101 and 102 are made of a conductive material that has the function of reflecting light and a material that transmits light. It may also be laminated with a conductive material having a function of passing through. In that case, electrode 101 and electrode 1 02 can resonate the light of a desired wavelength from each light-emitting layer and intensify the light of that wavelength. Therefore, it is preferable because it can have a function to adjust the optical distance.

[0311] The methods for forming the film of electrodes 101 and 102 include sputtering, vapor deposition, printing, and coating. MBE (Molecular Beam Epitaxy), CVD, Pulse Ray The deposition method, ALD (Atomic Layer Deposition), etc., are used as appropriate. It is possible.

[0312] Circuit board Furthermore, a light-emitting element according to one aspect of the present invention is placed on a substrate made of glass, plastic, or the like. It is fine to manufacture it. In terms of the order in which it is manufactured on the substrate, it is fine to stack them in order from the electrode 101 side. You may also stack them sequentially starting from pole 102.

[0313] Examples of substrates on which a light-emitting element according to one aspect of the present invention can be formed include glass and quartz. , or plastic can be used. A flexible substrate may also be used. A substrate is a flexible substrate that can be bent, for example, polycarbonate Examples include plastic substrates made of nate, polyarylate, etc. Also, films, Inorganic vapor-deposited films can also be used. Note: The manufacturing process for light-emitting elements and optical elements. Anything other than these that functions as a support in the context is acceptable. Alternatively, Any device that has the function of protecting optical elements and other optical components is acceptable.

[0314] For example, in the present invention, a light-emitting element can be formed using various substrates. The type of substrate is not particularly limited. One example of such a substrate is a semiconductor substrate (for example) (e.g., single crystal substrate or silicon substrate), SOI substrate, glass substrate, quartz substrate, plastic substrate Plates, metal substrates, stainless steel substrates, substrates having stainless steel foil, Tungsten substrate, substrate with tungsten foil, flexible substrate, laminated film Examples include paper containing fibrous materials, or substrate films. An example of a glass substrate is... Aluminoborosilicate glass, aluminoborosilicate glass, or soda-lime glass are examples of such materials. Examples of flexible substrates, laminated films, and base films include the following: For example, polyethylene terephthalate (PET), polyethylene naphthalate (P EN), polyethersulfone (PES), polytetrafluoroethylene (PTFE) There are representative plastics. Alternatively, one example is resins such as acrylic. Alternatively, as an example, polypropylene, polyester, polyvinyl fluoride, or polysalt Examples include vinyl oxides. Alternatively, one example is polyamide, polyimide, aramid, epoxy. Examples include xyloxy, inorganic vapor-deposited films, or paper.

[0315] Alternatively, a flexible substrate may be used as the substrate, and the light-emitting element may be formed directly on the flexible substrate. Alternatively, a release layer may be provided between the substrate and the light-emitting element. The release layer is provided on top of the light-emitting element. After partially or completely completing the child component, it is separated from the circuit board and used for transferring it to another circuit board. This allows for the transfer of light-emitting elements to substrates with poor heat resistance or flexible substrates. Oh, the aforementioned delamination layer has, for example, a laminated inorganic film structure of a tungsten film and a silicon oxide film. Configurations such as the one shown, or a configuration in which a resin film such as polyimide is formed on the substrate, can be used.

[0316] In other words, a light-emitting element is formed using one substrate, and then the light-emitting element is transferred to another substrate. The light-emitting element may be placed on a different substrate. An example of a substrate on which the light-emitting element is placed is the above In addition to the substrates mentioned above, there are also cellophane substrates, stone substrates, wood substrates, and cloth substrates (natural fibers (silk, cotton, Hemp), synthetic fibers (nylon, polyurethane, polyester) or regenerated fibers (acetate) (including t, cupro, rayon, recycled polyester, etc.), leather substrate, or rubber substrate. These substrates can be used to create light-emitting elements that are less prone to breakage and have high heat resistance. This can be a child, a lightweight light-emitting element, or a thinned light-emitting element.

[0317] Furthermore, a field-effect transistor (FET), for example, is formed on the aforementioned substrate, and the FET and The light-emitting element 150 may be fabricated on electrically connected electrodes. This allows the FET to This allows us to create an active-matrix type display device that controls the driving of the light-emitting element 150.

[0318] In this embodiment, one aspect of the present invention has been described. Or, other embodiments may be described. In this context, one aspect of the present invention will be described. However, this aspect of the present invention is not limited to these. Not done. In other words, various aspects of the invention are described in this embodiment and other embodiments. Therefore, one aspect of the present invention is not limited to a specific aspect. For example, one aspect of the present invention While an example of its application to a light-emitting element has been shown, one aspect of the present invention is not limited thereto. For example, depending on the circumstances, one aspect of the present invention may be suitable for a light-emitting element. It is not necessary to use it. Alternatively, for example, in one aspect of the present invention, the triplet excitation energy is used to emit light. A guest material having the ability to be converted to a host material, and at least one host material. Furthermore, the LUMO level of the guest material is higher than the LUMO level of the host material, and the H of the guest material An example has been shown where the OMO level is lower than the HOMO level of the host material, but this is one aspect of the present invention. This is not limited to the present invention. In some cases, or depending on the circumstances, one aspect of the present invention may be For example, the LUMO level of the guest material does not need to be higher than the LUMO level of the host material. Alternatively, if the HOMO level of the guest material is not lower than the HOMO level of the host material. Alternatively, for example, in one aspect of the present invention, the host material is a singlet excitation energy level. An example where the difference between the position and the triplet excitation energy level is greater than 0 eV and less than or equal to 0.2 eV. While the above has been shown, the present invention is not limited thereto. In some cases, or in some circumstances, Accordingly, in one aspect of the present invention, for example, the host material has a singlet excitation energy level and a triple The difference from the term excitation energy level may be greater than 0.2 eV.

[0319] The configuration shown in this embodiment can be used in appropriate combination with other embodiments. Cut.

[0320] (Embodiment 2) In this embodiment, the light-emitting element has a configuration different from that shown in Embodiment 1. The following explanation will be given using Figure 5. Note that in Figure 5(A), the same as shown in Figure 1(A) In areas with a similar function to the "su" code, the same hatching pattern is used, and the code is omitted in certain cases. There are also similar parts, which are denoted by the same symbols, and their detailed explanations are omitted. It may happen.

[0321] <Example of light-emitting element configuration> Figure 5(A) is a schematic cross-sectional view of the light-emitting element 250.

[0322] The light-emitting element 250 shown in Figure 5(A) has a pair of electrodes (electrode 101 and electrode 102) between them. , multiple light-emitting units (in Figure 5(A), light-emitting unit 106 and light-emitting unit 1 08) has. One of the multiple light-emitting units is shown in Figure 1 or It is preferable that the EL layer 100 has a similar configuration to that shown in Figure 3. In other words, the light-emitting element shown in Figure 1. Child 150 and the light-emitting element 152 shown in Figure 3 each have one light-emitting unit and a light-emitting element 25 0 preferably has multiple light-emitting units. Note that in the light-emitting element 250, electrode 1 Assuming that electrode 01 functions as the anode and electrode 102 functions as the cathode, the following explanation will be given, The configuration of the optical element 250 can be reversed.

[0323] Furthermore, in the light-emitting element 250 shown in Figure 5(A), the light-emitting unit 106 and the light-emitting unit 108 is stacked, and between the light-emitting unit 106 and the light-emitting unit 108 there is an electric current A bio-layer 115 is provided. Note that the light-emitting unit 106 and the light-emitting unit 108 have the same configuration. However, a different configuration is also acceptable. For example, the light-emitting unit 108 may have an EL layer as shown in Figure 1 or Figure 3. Using 100 is preferable.

[0324] Furthermore, the light-emitting element 250 has a light-emitting layer 120 and a light-emitting layer 170. In addition to the light-emitting layer 120, knit 106 also includes a hole injection layer 111, a hole transport layer 112, and an electron transport layer. It has a layer 113 and an electron injection layer 114. The light-emitting unit 108 also has a light-emitting layer 170 In addition, there is a hole injection layer 116, a hole transport layer 117, an electron transport layer 118, and an electron injection layer 11 It has 9.

[0325] The charge generation layer 115 is a hole transport material to which an acceptor substance, which is an electron acceptor, is added. Even with such a configuration, the electron transport material is combined with a donor substance that acts as an electron donor. This is also acceptable. Furthermore, both of these configurations may be stacked.

[0326] If the charge generation layer 115 contains a composite material of an organic compound and an acceptor substance, The composite material used is a composite material that can be used in the hole injection layer 111 shown in Embodiment 1. That's all. As for organic compounds, aromatic amine compounds, carbazole compounds, aromatic carbon compounds Various compounds are used, such as hydrogen and polymer compounds (oligomers, dendrimers, polymers, etc.). It can exist. Furthermore, as an organic compound, its hole mobility is 1 × 10⁻⁶. -6 cm 2 / Vs It is preferable to use a material that meets the above criteria. However, a material that has higher hole transport than electron transport. In that case, other substances may be used. Composite materials of organic compounds and acceptor substances. Because the material has excellent carrier injection and carrier transport properties, it enables low-voltage and low-current operation. It can be displayed. Furthermore, as with the light-emitting unit 108, the anode side surface of the light-emitting unit is When in contact with the charge generation layer 115, the charge generation layer 115 is the hole injection layer of the light-emitting unit. Alternatively, it can also serve as a hole transport layer, so the light-emitting unit may have a hole injection layer or A configuration without a hole transport layer is also acceptable.

[0327] Furthermore, the charge generation layer 115 is a layer containing a composite material of an organic compound and an acceptor substance, and other It may be formed as a laminated structure by combining layers made of the following materials. For example, organic A layer containing a composite material of a compound and an acceptor substance, and one selected from among electron-donating substances. A layer containing the compound and a compound with high electron transport properties may be formed by combining them. A layer containing a composite material of an organic compound and an acceptor substance is combined with a layer containing a transparent conductive film. They may be formed together.

[0328] Furthermore, the charge generation layer 115 sandwiched between the light-emitting unit 106 and the light-emitting unit 108 is electric When a voltage is applied to electrode 101 and electrode 102, electrons are injected into one of the light-emitting units. Any method that injects holes into the other light-emitting unit is acceptable. For example, in Figure 5(A), When a voltage is applied such that the potential of electrode 101 is higher than the potential of electrode 102, The charge generation layer 115 injects electrons into the light-emitting unit 106 and holes into the light-emitting unit 108. Enter.

[0329] Furthermore, the charge generation layer 115 has light transmission to visible light (specifically) from the viewpoint of light extraction efficiency. It is preferable that the charge generation layer 115 has a visible light transmittance of 40% or more. Furthermore, the charge generation layer 115 has lower conductivity than the pair of electrodes (electrode 101 and electrode 102). It still works.

[0330] By forming the charge generation layer 115 using the materials described above, the light-emitting layer is stacked in the field This can suppress the rise in drive voltage during operation.

[0331] Furthermore, Figure 5(A) illustrates a light-emitting element having two light-emitting units. However, the same principle can also be applied to light-emitting devices that have three or more light-emitting units stacked on top of each other. As shown in the light-emitting element 250, multiple light-emitting units are placed between a pair of electrodes in a charge generation layer. By partitioning and arranging the elements, high-brightness light emission is possible while maintaining a low current density, and further This enables the creation of light-emitting elements with a long lifespan. Furthermore, it enables the creation of light-emitting elements with low power consumption. .

[0332] Furthermore, of the multiple units, at least one unit has the configuration shown in Embodiment 1. By applying this technology, it is possible to provide a light-emitting element with high luminescence efficiency.

[0333] Furthermore, the light-emitting layer 170 of the light-emitting unit 108 is the same as the light-emitting layer 13 shown in Embodiment 1. It is preferable that it has a configuration similar to that of the light-emitting layer 135. By having a configuration similar to that of the light-emitting layer 130 or light-emitting layer 135 shown, the light-emitting element 250 Therefore, it is suitable as a light-emitting element with high luminescence efficiency.

[0334] Furthermore, as shown in Figure 5(B), the light-emitting layer 120 of the light-emitting unit 106 is a guest The device comprises material 121 and host material 122. The guest material 121 is a fluorescent material. The following explains this.

[0335] ≪Light-emitting mechanism of light-emitting layer 120≫ The light-emitting mechanism of the light-emitting layer 120 will be explained below.

[0336] Electrons injected from a pair of electrodes (electrode 101 and electrode 102) or a charge generation layer Excitons are generated when holes recombine in the light-emitting layer 120. Guest material 1 Compared to 21, there is a large amount of host material 122, so by generating excitons, the host material An excited state of material 122 is formed.

[0337] An exciton is a carrier (electron and hole) pair. An exciton has energy. Therefore, the material from which excitons are generated enters an excited state.

[0338] If the excited state of the formed host material 122 is a singlet excited state, then the host material 12 Singlet excitation energy is transferred from the S1 level of material 2 to the S1 level of guest material 121. Then, a singlet excited state is formed in guest material 121.

[0339] Since guest material 121 is a fluorescent material, the singlet excited state in guest material 121 Once formed, the guest material 121 rapidly emits light. In this case, to obtain high luminescence efficiency... Therefore, it is preferable that the fluorescence quantum yield of guest material 121 is high. The same applies in case 1, when carriers recombine and the resulting excited state is a singlet excited state. That is the case.

[0340] Next, when a triplet excited state of the host material 122 is formed by carrier recombination... This will be explained. The energy levels of the host material 122 and guest material 121 in this case. The correlation of the ranks is shown in Figure 5(C). The notation and symbols in Figure 5(C) are as follows: Furthermore, the T1 level of the host material 122 is lower than the T1 level of the guest material 121. Since this is preferable, Figure 5(C) illustrates this case, but the T1 level of the host material 122 This may be higher than the T1 level of guest material 121.

[0341] • Guest(121): Guest material 121 (fluorescent material) • Host(122): Host material 122 ·S FG : S1 level of guest material 121 (fluorescent material) ·T FG :T1 level of guest material 121 (fluorescent material) ·S FH : S1 level of host material 122 ·T FH :T1 level of host material 122

[0342] As shown in Figure 5(C), triplet-triplet annihilation (TTA: triplet-triplet annihilation) Triplets generated by carrier recombination (et annihilation) Excitons interact with each other, exchanging excitation energy and spin angular momentum. By doing so, the S1 level of the host material 122 (S FH ) possessing the energy of A reaction occurs that converts to a multiplet exciton (see Figure 5(C) TTA). Host material 122 The singlet excitation energy is S FH Therefore, guest material 121 has lower energy than that. S1 level (S FG Energy transfer occurs to (see Route E3 in Figure 5(C)), and the guest material A singlet excited state is formed in material 121, and the guest material 121 emits light.

[0343] Furthermore, if the density of triplet excitons in the light-emitting layer 120 is sufficiently high (for example, 1 × 10⁻¹⁰ -12 cm -3 (The above) ignores the deactivation of a single triplet exciton and considers two closely spaced triplet excitons. We can consider only the reaction caused by the initiator.

[0344] Furthermore, when carriers recombine in guest material 121 and a triplet excited state is formed... The triplet excited state of guest material 121 is thermally deactivated, making it difficult to utilize for luminescence. However, the T1 level (T) of the host material 122 FH ) is a T1 standard of guest material 121 Place(T FG If it is lower than ), the triplet excitation energy of guest material 121 is, 21 T1 levels (T FG ) from the T1 level of host material 122 (T FH Energy transfer to ) It is possible to do this (see Figure 5(C) Route E4), and it is then used for TTA.

[0345] In other words, the host material 122 has a triplet excitation energy, and a singlet excitation energy is obtained by TTA. It is preferable that it has the function of converting into energy. By doing so, the light generated in the light-emitting layer 120 A portion of the triplet excitation energy is obtained by singlet excitation energy by TTA in the host material 122. By converting it into energy and transferring the singlet excitation energy to the guest material 121, fluorescence It becomes possible to extract it as luminescence. To do this, the S1 level (S) of the host material 122 is needed. FH ) is the S1 level (S FG It is preferable that it is higher than ) Also, phos T1 level of material 122 (T FH ) is the T1 level (T FG ) lower It is preferable.

[0346] In particular, the T1 level of guest material 121 (T FG ) is the T1 level of the host material 122 ( T FH If it is lower than ), the weight ratio of host material 122 to guest material 121 is It is preferable that the weight ratio of the guest material 121 is low. Specifically, it is preferable that the host material 122 is 1 The weight ratio of guest material 121 to this is preferably greater than 0 and 0.05 or less. By using a weight ratio relationship, the probability of carrier recombination in guest material 121 is reduced. It is possible to also determine the T1 level (T) of the host material 122. FH ) Guest material 121 T 1 level (T FG This can reduce the probability of energy transfer occurring to ).

[0347] The host material 122 may be composed of a single compound, or it may be composed of multiple compounds. It's fine if it's done.

[0348] In addition, in each of the above configurations, the luminescent unit 106 and the luminescent unit 108 are used The light-emitting color exhibited by the material may be the same or different. Light-emitting unit 1 A guest material having the function of emitting light of the same color in both 06 and the light-emitting unit 108. In combination, the light-emitting element 250 is preferable as a light-emitting element that exhibits high luminous brightness with a low current value. Furthermore, the light-emitting unit 106 and the light-emitting unit 108 have a function that allows them to emit light of different colors. When a guest material is present, the light-emitting element 250 preferably becomes a light-emitting element that exhibits multicolor emission. In this case, either one or both of the light-emitting layer 120 and the light-emitting layer 170 have an emission wavelength. By using multiple different light-emitting materials, the emission spectrum exhibited by the light-emitting element 250 is Since the light is a composite of emission with different emission peaks, it has at least two maximum values. This results in an emission spectrum.

[0349] The above configuration is also suitable for obtaining white light emission. Light from the light-emitting layer 120 and the light-emitting layer 170 By making them complementary colors to each other, white light emission can be obtained. In particular, color rendering Guests should aim for high white light emission, or light emission that includes at least red, green, and blue. It is preferable to select the materials.

[0350] Furthermore, either one or both of the light-emitting layer 120 and the light-emitting layer 170 may be further divided into layers. Each of the divided layers may contain a different light-emitting material. Either or both of layer 120 and the light-emitting layer 170 are composed of two or more layers. It is also possible to stack the first light-emitting layer and the second light-emitting layer in order from the hole transport layer side. When using this as a light-emitting layer, a material having hole transport properties is used as the host material for the first light-emitting layer. One configuration involves using a material with electron transport properties as the host material for the second light-emitting layer. In this case, the light-emitting materials of the first light-emitting layer and the second light-emitting layer may be the same material but different materials. Even if they are materials, even if they have the function of emitting light of the same color, they may emit light of different colors. It may be a material having the function of exhibiting the following: It may have the function of exhibiting light emission of different colors from each other. The configuration, which has multiple light-emitting materials, produces high color rendering consisting of the three primary colors or four or more light-emitting colors. It is also possible to obtain white light emission.

[0351] Furthermore, the light-emitting unit 106 and the light-emitting unit 108 have guest materials with different light-emitting colors. In this case, the emission from the light-emitting layer 120 is on the shorter wavelength side than the emission from the light-emitting layer 170. It is preferable to have a configuration that has a -. A material having a high triplet excitation energy level The light-emitting element used tends to degrade in brightness quickly. Therefore, a light-emitting layer that exhibits short wavelength emission is used. By using TA, it is possible to provide light-emitting elements with minimal brightness degradation.

[0352] <Examples of materials that can be used for the light-emitting layer> Next, the materials that can be used for the light-emitting layer 120 and the light-emitting layer 170 will be described below. do.

[0353] <<Materials that can be used for the light-emitting layer 120>> In the light-emitting layer 120, the host material 122 is the most abundant by weight, and the guest material 121 The (fluorescent material) is dispersed in the host material 122. The S1 level of the host material 122 is The T1 level of host material 122 is higher than the S1 level of host material 121 (fluorescent material), and the G It is preferable that the level is lower than the T1 level of the fluorescent material 121.

[0354] In the light-emitting layer 120, there are no particular limitations on the guest material 121, but anthracene is also acceptable. Derivatives, tetracene derivatives, chrysene derivatives, phenanthrene derivatives, pyrene derivatives, Lylene derivatives, stilbene derivatives, acridone derivatives, coumarin derivatives, phenoxazine Derivatives, phenothiazine derivatives, etc., are preferred, and for example, the following materials can be used. .

[0355] Specifically, 5,6-bis[4-(10-phenyl-9-antryl)phenyl]-2 ,2'-bipyridine (abbreviation: PAP2BPy), 5,6-bis[4'-(10-phenyl -9-anthryl)biphenyl-4-yl]-2,2'-bipyridine (abbreviation: PAPP2) BPy), N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorine) [Len-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: 1,6mMem FLPAPrn), N,N'-bis[4-(9-phenyl-9H-fluoren-9-yl) )phenyl]-N,N'-bis(4-tert-butylphenyl)pyrene-1,6-dia Min (abbreviation: 1,6tBu-FLPAPrn), N,N'-diphenyl-N,N'-bis [4-(9-phenyl-9H-fluoren-9-yl)phenyl]-3,8-dicyclophenyl Xylpyrene-1,6-diamine (abbreviation: ch-1,6FLPAPrn), N,N'-bi Su[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbe n-4,4'-diamine (abbreviation: YGA2S), 4-(9H-carbazole-9-yl) -4'-(10-phenyl-9-anthryl)triphenylamine (abbreviation: YGAPA) , 4-(9H-carbazol-9-yl)-4'-(9,10-diphenyl-2-ant) Lyl)triphenylamine (abbreviation: 2YGAPPA), N,9-diphenyl-N-[4- (10-phenyl-9-anthryl)phenyl]-9H-carbazole-3-amine (abbreviated) Name: PCAPA), Perylene, 2,5,8,11-Tetra(tert-butyl)perylene (Abbreviation: TBP), 4-(10-phenyl-9-antryl)-4'-(9-phenyl- 9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPA), N,N' '-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene) Bis[N,N',N'-triphenyl-1,4-phenylenediamine] (abbreviation: DPAB) PA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthryl) [enyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9 ,10-diphenyl-2-anthryl)phenyl]-N,N',N'-triphenyl-1 ,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N'',N '',N''',N'''-Octaphenyldibenzo[g,p]chrysene-2,7,10 ,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9,10-diphenyl -2-anthryl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2 PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-ant [Lyl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPh) A) N-(9,10-diphenyl-2-anthryl)-N,N',N'-triphenyl -1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1 '-biphenyl-2-yl)-2-anthryl]-N,N',N'-triphenyl-1, 4-phenylenediamine (abbreviation: 2DPABPhA), 9,10-bis(1,1'-bis( (phenyl-2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-f Phenylanthracene-2-amine (abbreviation: 2YGABPhA), N,N,9-triphenyl Luanthracene-9-amine (abbreviation: DPhAPhA), Coumarin 6, Coumarin 545T N,N'-diphenylquinacridone (abbreviation: DPQd), rubren, 2,8-di-te rt-butyl-5,11-bis(4-tert-butylphenyl)-6,12-diphenyl Lutetracene (abbreviation: TBRb), Nile Red, 5,12-bis(1,1'-biphenyl Lu-4-yl)-6,11-diphenyltetracene (abbreviation: BPT), 2-(2-{2- [4-(dimethylamino)phenyl]ethenyl}-6-methyl-4H-pyran-4-yly Dene)propanedinitrile (abbreviation: DCM1), 2-{2-methyl-6-[2-(2,3 ,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl)ethenyl ]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCM2), N,N,N ',N'-Tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-meth (p) acenaphtho[1,2-a]fluorantene-3,10-diamine (abbreviation: p -mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethicone)] Ru-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinoridine-9-yl )Ethenyl]-4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTI) , 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3, 6,7-Tetrahydro-1H,5H-Benzo[ij]quinoridine-9-yl)ethenyl -4H-pyran-4-ylidene}propanedinitrile (abbreviation: DCJTB), 2-(2, 6-Bis{2-[4-(dimethylamino)phenyl]ethenyl}-4H-pyran-4-i (Liden)propanedinitrile (abbreviation: BisDCM), 2-{2,6-bis[2-(8- Methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H -Benzo[ij]quinoridine-9-yl)ethenyl]-4H-pyran-4-ylidene} Ropanedinitrile (abbreviation: BisDCJ™), 5,10,15,20-tetraphenyl Bisbenzo[5,6]indeno[1,2,3-cd:1',2',3'-lm]perylene These are some examples.

[0356] Furthermore, in the light-emitting layer 120, the materials that can be used for the host material 122 are: There are no particular limitations, but for example, tris(8-quinolinolato)aluminum(III) (abbreviation) :Alq), Tris(4-methyl-8-quinolinolato)aluminum(III) (abbreviation: Almq3), bis(10-hydroxybenzo[h]quinolinato)beryllium(II) Abbreviation: BeBq2), bis(2-methyl-8-quinolinolate)(4-phenylphenolate ) Aluminum(III) (abbreviation: BAlq), bis(8-quinolinolato)zinc(II) (Abbreviation: Znq), bis[2-(2-benzoxazolyl)phenolate]zinc(II) Abbreviation: ZnPBO), bis[2-(2-benzothiazolyl)phenolate]zinc(II) Metal complexes such as (abbreviated as ZnBTZ), 2-(4-biphenylyl)-5-(4-tert- Butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5 -(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]ben Zen (abbreviation: OXD-7), 3-(4-biphenylyl)-4-phenyl-5-(4-te rt-butylphenyl)-1,2,4-triazole (abbreviation: TAZ), 2,2',2' -(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzoimidazo Vasophenanthroline (abbreviation: TPBI), Vasophenanthroline (abbreviation: BPhen), Vasocuproline (Abbreviation: BCP), 9-[4-(5-phenyl-1,3,4-oxadiazole-2- Heterocyclic compounds such as yl(phenyl)-9H-carbazole (abbreviation: CO11), 4,4 '-Bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB) (α-NPD), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1 ,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-( Spiro-9,9'-bifluoren-2-yl)-N-phenylamino]biphenyl (abbreviation) Examples include aromatic amine compounds such as BSPB. Also, anthracene derivatives, ferrous compounds, etc. Nanthrene derivatives, pyrene derivatives, chrysene derivatives, dibenzo[g,p]chrysene derivatives Examples include condensed polycyclic aromatic compounds such as 9,10-diphenylanthracene (Abbreviation: DPAnth), N,N-diphenyl-9-[4-(10-phenyl-9-Anth) Tolyl)phenyl]-9H-carbazole-3-amine (abbreviation: CzA1PA), 4-( 10-phenyl-9-anthryl)triphenylamine (abbreviation: DPhPA), 4-(9 H-carbazole-9-yl)-4'-(10-phenyl-9-antryl)triphenyl Luamine (abbreviation: YGAPA), N,9-diphenyl-N-[4-(10-phenyl-9 -Anthryl)phenyl]-9H-carbazole-3-amine (abbreviation: PCAPA), N ,9-diphenyl-N-{4-[4-(10-phenyl-9-antryl)phenyl]f phenyl-9H-carbazole-3-amine (abbreviation: PCAPBA), N,9-diphenyl ru-N-(9,10-diphenyl-2-anthryl)-9H-carbazole-3-amine (Abbreviation: 2PCAPA), 6,12-dimethoxy-5,11-diphenylchrysene, N, N,N',N',N'',N'',N''',N'''-Octaphenyldibenzo[g, p]chrysene-2,7,10,15-tetraamine (abbreviation: DBC1), 9-[4-(1 O-phenyl-9-antryl)phenyl]-9H-carbazole (abbreviation: CzPA), 3,6-diphenyl-9-[4-(10-phenyl-9-antryl)phenyl]-9H -Carbazole (abbreviation: DPCzPA), 9,10-bis(3,5-diphenylphenyl )Anthracene (abbreviation: DPPA), 9,10-di(2-naphthyl)anthracene (abbreviation :DNA), 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviation) :t-BuDNA), 9,9'-biantril (abbreviation: BANT), 9,9'-(still Ben-3,3'-diphenanthrene (abbreviation: DPNS), 9,9'-(stilbe n-4,4'-diyl)diphenanthrene (abbreviation: DPNS2), 1,3,5-tri(1 Examples include pyrenyl benzene (abbreviated as TPB3). Furthermore, these and From among known materials, an energy greater than the energy gap of the above guest material 121 You can use one or more materials that have gaps.

[0357] The light-emitting layer 120 can also be composed of two or more layers. For example, the first When the first light-emitting layer and the second light-emitting layer are stacked in order from the hole transport layer side to form the light-emitting layer 120, A material having hole transport properties is used as the host material for the first light-emitting layer, and the host material for the second light-emitting layer One such configuration involves using materials that possess electron-transporting properties.

[0358] Furthermore, in the light-emitting layer 120, the host material 122 is composed of a certain compound. It is also fine if it is composed of multiple compounds. Alternatively, in the light-emitting layer 120, It may also contain materials other than stock material 122 and guest material 121.

[0359] <<Materials that can be used for the light-emitting layer 170>> Materials that can be used for the light-emitting layer 170 include those used for the light-emitting layer shown in Embodiment 1 above. Any material that can be used is acceptable. By using this material in the light-emitting layer 170, a light-emitting element with high luminescence efficiency can be fabricated. ru.

[0360] Furthermore, there are no limitations on the emission color of the light-emitting material contained in the light-emitting layer 120 and the light-emitting layer 170. They can be the same or different. The light emitted from each is mixed and extracted outside the element. Therefore, for example, if the light-emitting elements of both are complementary colors, the light-emitting element will emit white light. It can be given. Considering the reliability of the light-emitting element, the light-emitting material included in the light-emitting layer 120 The emission peak wavelength is preferably shorter than that of the light-emitting material contained in the emission layer 170.

[0361] Furthermore, the light-emitting unit 106, the light-emitting unit 108, and the charge generation layer 115 are produced by a vapor deposition method. Formed by methods such as vacuum deposition, inkjet printing, coating, and gravure printing. It is possible.

[0362] The configuration shown in this embodiment can be used in appropriate combination with the configurations shown in other embodiments. It is possible to be there.

[0363] (Embodiment 3) In this embodiment, the light-emitting element has a configuration different from that shown in Embodiments 1 and 2. An example of this will be explained below using Figures 6 to 9.

[0364] <Example of light-emitting element configuration 1> Figures 6(A) and 6(B) are cross-sectional views showing a light-emitting element according to one embodiment of the present invention. In (B), the same hatching is used in areas that have the same function as the symbols shown in Figure 1(A). In some cases, the code may be omitted as a pattern. Also, similar functions are used in similar places. Symbols may be used, and detailed explanations may be omitted.

[0365] The light-emitting elements 260a and 260b shown in Figures 6(A) and 6(B) are connected to the substrate 200 side. It may also be a bottom-emission type light-emitting element that extracts from the substrate 200 and It may also be a top-emission type light-emitting element that extracts light in the opposite direction. However, one aspect of the present invention is not limited thereto, and the light emitted by the light-emitting element is directed above the substrate 200. It may also be a dual-emission type light-emitting element that emits light from both the upper and lower sides. .

[0366] When the light-emitting element 260a and light-emitting element 260b are of the bottom emission type, electrode 1 Preferably, 01 has the function of transmitting light. Also, electrode 102 reflects light. It is preferable that the light-emitting element 260a and the light-emitting element 260b have a function. In the case of a top-emission type, it is preferable that the electrode 101 has the function of reflecting light. Furthermore, it is preferable that the electrode 102 has the function of transmitting light.

[0367] The light-emitting element 260a and the light-emitting element 260b have an electrode 101 and an electrode 102 on the substrate 200. It has the following: In addition, between electrode 101 and electrode 102, there is a light-emitting layer 123B and a light-emitting layer 123 It has G and a light-emitting layer 123R. It also has a hole injection layer 111 and a hole transport layer 112. It has an electron transport layer 118 and an electron injection layer 119.

[0368] Furthermore, the light-emitting element 260b is part of the configuration of the electrode 101, and the conductive layer 101a and the conductive It has a conductive layer 101b on layer 101a and a conductive layer 101c below the conductive layer 101a. In other words, the light-emitting element 260b has a conductive layer 101a, a conductive layer 101b, and a conductive layer 101c. It has a configuration of clamped electrodes 101.

[0369] In the light-emitting element 260b, the conductive layer 101b and the conductive layer 101c are made of different materials. It may be done in this way, or it may be formed from the same material. The electrode 101 may be sandwiched between the same conductive material. If the configuration is such that the pattern shape is formed by the etching process during the formation of the electrode 101 This is preferable because it makes the process easier.

[0370] Furthermore, in the light-emitting element 260b, in the conductive layer 101b or the conductive layer 101c, A configuration having only one of the two offsets is also acceptable.

[0371] Furthermore, the conductive layers 101a, 101b, and 101c of the electrode 101 are each implemented The same configuration and materials as those used for electrode 101 or electrode 102 shown in Form 1 can be used. Cut.

[0372] In Figures 6(A) and 6(B), the region 221B is sandwiched between electrodes 101 and 102. A partition wall 145 is located between region 221G and region 221R. The partition wall 145 provides insulation. The partition wall 145 covers the end of the electrode 101 and has an opening that overlaps with the electrode. By providing the wall 145, the electrodes 101 on the substrate 200 in each region are arranged in island-like formations. It becomes possible to separate them.

[0373] Furthermore, in the region where the light-emitting layer 123B and the light-emitting layer 123G overlap with the partition wall 145, They may have overlapping regions. Alternatively, the light-emitting layer 123G and the light-emitting layer 123R may have overlapping regions. In the region where it overlaps with the partition wall 145, it may have overlapping regions. In the region where the light-emitting layer 123R and the light-emitting layer 123B overlap with the partition wall 145, It may have an overlapping region.

[0374] The partition wall 145 only needs to be insulating and is formed using an inorganic or organic material. The inorganic materials include silicon oxide, silicon oxide nitride, silicon nitride oxide, silicon nitride silicon Examples of organic materials include aluminum oxide, aluminum nitride, etc. Examples include photosensitive resin materials such as acrylic resin or polyimide resin.

[0375] Furthermore, a silicon oxidizride film is a film whose composition contains more oxygen than nitrogen. Preferably, oxygen is 55 atomic% or more and 65 atomic% or less, and nitrogen is 1 atomic% or more and 20 atomic%. Below, silicon is 25 atomic% to 35 atomic%, and hydrogen is 0.1 atomic% to 10 atomic%. This refers to films that fall within the range below. A silicon nitride oxide film is a film whose composition contains more nitrogen than oxygen. This refers to a membrane with a high element content, preferably containing 55 atomic% or more and 65 atomic% or less of nitrogen, and 1 atomic% of oxygen. Atomic percent to 20 atomic percent, silicon 25 atomic percent to 35 atomic percent, hydrogen 0.1 atomic percent This refers to a film containing a substance in a concentration range of 10% to 10 atomic%.

[0376] Furthermore, the light-emitting layer 123R, light-emitting layer 123G, and light-emitting layer 123B each exhibit different colors. It is preferable to have a light-emitting material that has the function of emitting red light. For example, the light-emitting layer 123R exhibits red light. By having a light-emitting material that has the function of, region 221R exhibits red light emission, and light-emitting layer 12 Region 221G emits green light because region 3G has a light-emitting material that exhibits a green light. The light-emitting layer 123B has a light-emitting material that exhibits a blue color, thus region 221 B emits blue light. A light-emitting element 260a or light-emitting element 26 has such a configuration. By using 0b as the pixel of the display device, a display device capable of full-color display can be manufactured. This is possible. Also, the film thickness of each light-emitting layer may be the same or different. good.

[0377] Additionally, one or more of the light-emitting layers 123B, 123G, and 123R. The light-emitting layer is at least one of the light-emitting layers 130 and 135 shown in Embodiment 1. It is preferable to have two configurations. By doing so, a light-emitting element with good luminescence efficiency can be fabricated. It is possible.

[0378] Note that one or more of the light-emitting layers 123B, 123G, and 123R may be present. The light-emitting layer may be configured with two or more layers stacked on top of each other.

[0379] As described above, at least one light-emitting layer emits light as shown in Embodiments 1 and 2. Having a layered structure, the light-emitting element 260a or light-emitting element 260b having the light-emitting layer is used as a display device. By using it in the pixels, a display device with high luminous efficiency can be manufactured. That is, A display device having a light-emitting element 260a or a light-emitting element 260b reduces power consumption. It is possible.

[0380] Furthermore, in the direction from which light is extracted from the electrode that extracts light, an optical element (for example, a color filter) is placed. By providing polarizing plates, anti-reflective coatings, etc., the color purity of the light-emitting element 260a and the light-emitting element 260b is improved. The degree can be improved. Therefore, the light-emitting element 260a or light-emitting element 260b The color purity of the display device can be improved. Alternatively, the light-emitting element 260a and the light-emitting element can be improved. External light reflection of 260b can be reduced. Therefore, the light-emitting element 260a or light-emitting element The contrast ratio of a display device having sub-element 260b can be increased.

[0381] Furthermore, other configurations of the light-emitting element 260a and light-emitting element 260b are as follows: The configuration of the light-emitting element in Embodiment 1 and Embodiment 2 should be taken into consideration.

[0382] <Example of light-emitting element configuration 2> Next, Figures 7(A) and 7(B) show examples of configurations different from the light-emitting elements shown in Figures 6(A) and 6(B). We will use this to provide the following explanation.

[0383] Figures 7(A) and 7(B) are cross-sectional views showing a light-emitting element according to one embodiment of the present invention. In (B), the same symbols are used for parts that have the same function as those shown in Figures 6(A) and (B). A hatch pattern may be used, and the symbols may be omitted. Also, in areas with similar functions, Similar symbols may be used, and their detailed explanations may be omitted.

[0384] Figures 7(A) and 7(B) show examples of the configuration of a light-emitting element having a light-emitting layer between a pair of electrodes. The light-emitting element 262a shown in (A) is an upper-surface emitter that extracts light in the direction opposite to the substrate 200. The light-emitting element of the (up-emission) type, the light-emitting element 262b shown in Figure 7(B), is on the substrate 200 side. This is a bottom-emission type light-emitting element that extracts light from the bottom. One embodiment is not limited thereto, and the light emitted by the light-emitting element is on the substrate 200 on which the light-emitting element is formed. It may also be a dual-emission type that extracts material from both the front and the bottom.

[0385] The light-emitting element 262a and the light-emitting element 262b have an electrode 101 and an electrode 102 on the substrate 200. It has electrode 103 and electrode 104. Also, between electrode 101 and electrode 102, At least light is emitted between electrode 102 and electrode 103, and between electrode 102 and electrode 104. It has a layer 170, a light-emitting layer 190, and a charge-generating layer 115. It also has a hole injection layer 111 and , hole transport layer 112, electron transport layer 113, electron injection layer 114, hole injection layer 116 It has a hole transport layer 117, an electron transport layer 118, and an electron injection layer 119.

[0386] Furthermore, the electrode 101 consists of a conductive layer 101a and a conductive layer 101b that is in contact with the conductive layer 101a. , has . Furthermore, electrode 103 has a conductive layer 103a and a conductive layer in contact with the conductive layer 103a 103b and Electrode 104 has a conductive layer 104a and a conductive layer in contact with the conductive layer 104a. It has an electrolytic layer 104b.

[0387] The light-emitting element 262a shown in Figure 7(A) and the light-emitting element 262b shown in Figure 7(B) are electrodes Region 222B sandwiched between electrode 101 and electrode 102, sandwiched between electrode 102 and electrode 103 Between region 222G and region 222R sandwiched between electrode 102 and electrode 104, It has a wall 145. The partition wall 145 is insulating. The partition wall 145 has electrodes 101 and 1 03, and the end of electrode 104 are covered, and the partition wall 145 has an opening that overlaps with the electrode. By doing so, the electrodes on the substrate 200 in each region can be separated into island-like structures. It becomes Noh.

[0388] Furthermore, the charge generation layer 115 is made of a hole transport material to which electron acceptors are attached. By adding materials, or by adding electron donors to electron transport materials, It can be formed if the conductivity of the charge generation layer 115 is as high as that of the pair of electrodes. In addition, the carriers generated by the charge generation layer 115 flow to the adjacent pixels, and then to the adjacent pixels In some cases, the element may emit light unintentionally. Therefore, it is necessary to suppress the unauthorized emission of light from adjacent pixels. In order to achieve this, the charge generation layer 115 is formed of a material with lower conductivity than the pair of electrodes. preferable.

[0389] Furthermore, the light-emitting element 262a and the light-emitting element 262b are located in region 222B, region 222G, and In the direction from which the light emitted from region 222R is extracted, the optical element 224B and the optical element are respectively positioned. The substrate 220 has a sub-element 224G and an optical element 224R. Light emitted from each region It is emitted to the outside of the light-emitting element through each optical element. That is, it is emitted from region 222B. The light is emitted through the optical element 224B, and the light emitted from region 222G is emitted through the optical element The light emitted through 224G and emanating from region 222R is transmitted through optical element 224R. It is launched.

[0390] Furthermore, optical elements 224B, 224G, and 224R receive incident light It has the function of selectively transmitting light exhibiting a specific color. For example, optical element 224B The light emitted from region 222B through the optical element 22 becomes blue light. The light emitted from region 222G via 4G becomes green light, and the optical element The light emitted from region 222R via sub-element 224R is red in color.

[0391] Optical elements 224R, 224G, and 224B include, for example, a colored layer ( Color filters (also called color filters), bandpass filters, and multilayer filters can be applied. Furthermore, a color conversion element can be applied to an optical element. The color conversion element converts the incident light to... This is an optical element that converts light to wavelengths longer than the wavelength of the light in question. It uses quantum dots as color conversion elements. It is preferable to use an element that employs quantum dots. By using quantum dots, the color reproducibility of the display device can be improved. It can improve.

[0392] Furthermore, other optical elements may be placed on optical elements 224R, 224G, and 224B. One or more of these may be arranged in a stack. Other optical elements include, for example, circular polarizers and anti-reflective coatings. A protective film can be provided. The circular polarizing plate is used to extract light emitted from the light-emitting element of the display device. When placed on the receiving side, light incident from outside the display device is reflected inside the display device, and the outside This prevents the phenomenon of ejection from the part. In addition, by providing an anti-reflective coating, the surface of the display device This can reduce the amount of ambient light reflected by the device. This makes the light emitted by the display device clearer. It can be observed.

[0393] In Figures 7(A) and 7(B), the light emitted from each region through each optical element is referred to as blue. Let light exhibiting color (B), light exhibiting green (G), and light exhibiting red (R) be defined as follows: This is schematically illustrated with dashed arrows.

[0394] Furthermore, a light-shielding layer 223 is provided between each optical element. The light-shielding layer 223 is provided in adjacent regions or It has the function of blocking the light emitted from it. Furthermore, a configuration without the light-blocking layer 223 is also acceptable. stomach.

[0395] The light-shielding layer 223 has the function of suppressing the reflection of external light. Alternatively, the light-shielding layer 223 and Therefore, it has the function of preventing the mixing of colors of light emitted from adjacent light-emitting elements. Light-shielding layer 223 and For example, metals, resins containing black pigments, carbon black, metal oxides, and multiple metal oxides. A composite oxide containing a solid solution of a substance can be used.

[0396] Furthermore, optical element 224B and optical element 224G are in the region where they overlap with the light-shielding layer 223. They may have overlapping regions. Alternatively, optical element 224G and optical element 224R refers to the region in which the light-shielding layer 223 overlaps, even if there are overlapping regions between them. Good. Alternatively, optical element 224R and optical element 224B are superimposed on the light-shielding layer 223. Within a given domain, there may be overlapping regions.

[0397] Furthermore, the configuration of the substrate 200 and the substrate 220 having optical elements is as follows: Embodiment 1 You can take it into consideration.

[0398] Furthermore, the light-emitting elements 262a and 262b have a microcavity structure. .

[0399] <<Microcavity structure>> Light emitted from the light-emitting layer 170 and the light-emitting layer 190 is directed to a pair of electrodes (for example, electrode 10 Resonance occurs between 1 and electrode 102). Also, the light-emitting layer 170 and light-emitting layer 190 are emitted. It is formed at a position where the light of a desired wavelength is intensified among the incoming light. For example, in the reflection region of electrode 101 The optical distance from the light-emitting region of the light-emitting layer 170 to the optical distance from the reflection region of the electrode 102 to the light-emitting layer 170 By adjusting the optical distance to the light-emitting region, the light emitted from the light-emitting layer 170 can be controlled. This allows for the enhancement of light of a desired wavelength. Also, from the reflection region of electrode 101 to the light-emitting layer 190 The optical distance to the light-emitting region and the distance from the reflection region of electrode 102 to the light-emitting region of light-emitting layer 190. By adjusting the optical distance, the desired wavelength of light emitted from the light-emitting layer 190 can be selected. The light can be intensified. That is, multiple light-emitting layers (here, light-emitting layer 170 and light-emitting layer In the case of a light-emitting element that stacks 190), the optical distance between the light-emitting layer 170 and the light-emitting layer 190 is It is preferable to optimize the separation.

[0400] Furthermore, in the light-emitting element 262a and light-emitting element 262b, a conductive layer (conductive layer 1) is present in each region. By adjusting the thickness of 01b, conductive layer 103b, and conductive layer 104b), the light-emitting layer 170 Furthermore, it is possible to enhance the light of a desired wavelength from the light emitted from the light-emitting layer 190. In the region, at least one of the hole injection layer 111 and the hole transport layer 112 has a different thickness. This may enhance the light emitted from the light-emitting layer 170 and the light-emitting layer 190.

[0401] For example, electrodes 101 to 104 are made of a conductive material that has the function of reflecting light. When the refractive index is smaller than the refractive index of the light-emitting layer 170 or the light-emitting layer 190, the electrode The thickness of the conductive layer 101b on 101 is determined by the optical distance between electrode 101 and electrode 102 being m B λ B / 2(m B λ is a natural number, B(These represent the wavelengths of light that are strengthened in region 222B.) Adjust to achieve this. Similarly, the thickness of the conductive layer 103b on electrode 103 is adjusted to match electrode 103 and The optical distance between electrode 102 is m G λ G / 2(m G λ is a natural number, G Stronger in region 222G The wavelengths of light are adjusted to be (represented by). Furthermore, the conductive layer of electrode 104 The film thickness of 104b is such that the optical distance between electrode 104 and electrode 102 is m R λ R / 2(m R is natural number, λ R The wavelengths of light that are strengthened in region 222R are adjusted accordingly.

[0402] Furthermore, if it is difficult to precisely determine the reflection region of electrodes 101 to 104, By assuming that any region of electrode 101 to electrode 104 is a reflective region, the light-emitting layer 170 or The optical distance at which the light emitted from the light layer 190 is intensified may be derived. Also, the light-emitting layer 170 If it is difficult to precisely determine the light-emitting region of the light-emitting layer 190, the light-emitting layer 170 and By assuming that any region of the light layer 190 is an emission region, the emission layer 170 and the emission layer 190 You may also derive the optical distance at which the light emitted from the source is intensified.

[0403] As described above, a microcavity structure is provided, and the optical distance between the pair of electrodes in each region is adjusted. By optimizing the surface, light scattering and absorption near each electrode are suppressed, resulting in a high light extraction efficiency. It is possible to achieve this rate.

[0404] In the above configuration, conductive layer 101b, conductive layer 103b, and conductive layer 104b are light It is preferable that the conductive layer 101b, conductive layer 103b, and conductive The materials constituting layer 104b may be the same or different. When the same material is used for the electrical layer 101b, the conductive layer 103b, and the conductive layer 104b, electrode 10 1. Pattern formation by etching process during the formation of electrodes 103 and 104 is acceptable. This is preferable because it makes things easier. Also, conductive layers 101b, 103b, and 104b are Each layer may have a configuration consisting of two or more layers stacked on top of each other.

[0405] Note that the light-emitting element 262a shown in Figure 7(A) is an upward-emitting type light-emitting element, and therefore is conductive Layer 101a, conductive layer 103a, and conductive layer 104a have the function of reflecting light. Preferably, the electrode 102 has both the function of transmitting light and the function of reflecting light. It is preferable.

[0406] Furthermore, the light-emitting element 262b shown in Figure 7(B) is a bottom-export type light-emitting element, therefore it is conductive Layer 101a, conductive layer 103a, and conductive layer 104a have the function of transmitting light and the function of reflecting light. It is preferable that the electrode 102 has the ability to reflect light. preferable.

[0407] Furthermore, in the light-emitting element 262a and light-emitting element 262b, conductive layer 101a, conductive layer 10 The same material may be used for 3a or the conductive layer 104a, or different materials may be used. When the same material is used for conductive layer 101a, conductive layer 103a, and conductive layer 104a, the light-emitting element The manufacturing costs of the sub-element 262a and the light-emitting element 262b can be reduced. The electrical layer 103a and the conductive layer 104a may each have a configuration in which two or more layers are stacked. stomach.

[0408] Furthermore, the light-emitting layers 170 and 190 in the light-emitting elements 262a and 262b At least one of the configurations shown in Embodiment 1 and Embodiment 2 is included. It is preferable to have this. By doing so, a light-emitting element exhibiting high luminescence efficiency can be fabricated. It is possible.

[0409] Furthermore, the light-emitting layer 170 and the light-emitting layer 190 are, for example, light-emitting layer 190a and light-emitting layer 190b Thus, a configuration in which two layers are stacked on one or both sides may be used. The two light-emitting layers include the first Two types of light-emitting materials, a compound and a second compound, which have the function of exhibiting different colors, are used. By using them, multiple light emission can be obtained simultaneously. In particular, the light emission layer 170 and the light emission layer Select the light-emitting material to be used in each light-emitting layer so that the light emitted by 190 results in a white color. And that is preferable.

[0410] Furthermore, the light-emitting layer 170 or the light-emitting layer 190 has a structure in which three or more layers are stacked, either one or both. It may be a composite material, and may also include a layer that does not contain luminescent material.

[0411] As described above, the configuration of the light-emitting layer shown in Embodiment 1 and Embodiment 2 is at least one By using the light-emitting element 262a or light-emitting element 262b as a pixel of a display device, A display device with high light efficiency can be fabricated. That is, the light-emitting element 262a or the light-emitting element A display device having element 262b can reduce power consumption.

[0412] Regarding the other configurations of the light-emitting element 262a and light-emitting element 262b, 260a or light-emitting element 260b, or the light-emitting elements shown in Embodiment 1 and Embodiment 2 You should consider the configuration of the optical element.

[0413] <Method for fabricating a light-emitting element> Next, a method for manufacturing a light-emitting element according to one aspect of the present invention will be described below with reference to Figures 8 and 9. This will be done. Here, we will explain the method for fabricating the light-emitting element 262a shown in Figure 7(A). ru.

[0414] Figures 8 and 9 are cross-sectional views illustrating a method for manufacturing a light-emitting element according to one embodiment of the present invention. .

[0415] The method for fabricating the light-emitting element 262a described below comprises seven steps, from the first to the seventh. ru.

[0416] ≪Step 1≫ The first step is to create electrodes for the light-emitting element (specifically, conductive layers 101 that constitute the electrodes 101). a) conductive layer 103a constituting electrode 103, and conductive layer 104a constituting electrode 104) This is the process of forming it on the substrate 200 (see Figure 8(A)).

[0417] In this embodiment, a conductive layer having the function of reflecting light is formed on the substrate 200. By processing the conductive layer into a desired shape, conductive layer 101a, conductive layer 103a, and conductive Layer 104a is formed. The conductive layer having the function of reflecting light is made of silver and palladium. A copper alloy film (also called Ag-Pd-Cu film or APC) is used. The process of processing the same conductive layer to form the electrical layer 101a, conductive layer 103a, and conductive layer 104a. This method is preferable because it allows for lower manufacturing costs.

[0418] Note that before the first step, multiple transistors may be formed on the substrate 200. Furthermore, the plurality of transistors, conductive layer 101a, conductive layer 103a, and conductive layer 104a They may be electrically connected to each other.

[0419] ≪Step 2≫ The second step is to have a light-transmitting function on the conductive layer 101a that constitutes the electrode 101. A conductive layer 101b is placed on the conductive layer 103a constituting the electrode 103, and has the function of transmitting light. A conductive layer 103b is placed on the conductive layer 104a constituting the electrode 104, and has the function of transmitting light. This is the step of forming the conductive layer 104b (see Figure 8(B)).

[0420] In this embodiment, conductive layers 101a, 103a, and have the function of reflecting light, On 104a, there are conductive layers 101b, 103b, and respectively, which have the function of transmitting light. By forming 104b, electrodes 101, 103, and 104 are formed. ITSO films are used as the conductive layers 101b, 103b, and 104b.

[0421] Furthermore, the conductive layers 101b, 103b, and 104b, which have the function of transmitting light, can be used multiple times. It may be formed in stages. By forming it in stages, suitable microcaches can be formed in each region. The conductive layers 101b, 103b, and 104b can be formed with a film thickness that creates a vitreous structure. Cut.

[0422] ≪Step 3≫ The third step is to form partition walls 145 that cover the ends of each electrode of the light-emitting element. See Figure 8(C).

[0423] The partition wall 145 has an opening that overlaps with the electrode. The conductive film exposed by the opening. This functions as the anode of the light-emitting element. In this embodiment, the partition wall 145 is made of polyimide resin. Use fat.

[0424] Furthermore, in steps 1 to 3, the EL layer (the layer containing organic compounds) is damaged. Because there is no risk, various film formation methods and microfabrication techniques can be applied. This involves forming a reflective conductive layer using a sputtering method, and then using a lithography method to... A pattern is formed on the electrode layer, and then a dry etching method or a wet etching method is used. Then, by processing the conductive layer into an island shape, the conductive layer 101a and electrode 10 constitute the electrode 101. A conductive layer 103a constituting 3 and a conductive layer 104a constituting electrode 104 are formed. Subsequently, a transparent conductive film is deposited using the sputtering method, and then lithography is used. Then, a pattern is formed on the transparent conductive film, and then a wet etching method is used. Then, the transparent conductive film is processed into an island shape to form electrodes 101, 103, and 104. ru.

[0425] ≪Step 4≫ The fourth step involves a hole injection layer 111, a hole transport layer 112, a light-emitting layer 190, and an electron transport layer. This is a step to form 113, an electron injection layer 114, and a charge generation layer 115 (see Figure 9(A)). (see).

[0426] As the hole injection layer 111, a material containing a hole transporting material and an acceptor material is co-evaporated. It can be formed by deposition. Co-deposition is the process of depositing multiple different materials together. This is a vapor deposition method in which evaporation occurs simultaneously from an evaporation source. In addition, the hole transport layer 112 is a hole It can be formed by depositing a transportable material.

[0427] The light-emitting layer 190 can be purple, blue, blue-green, green, yellow-green, yellow, orange, or red. By depositing at least one luminescent guest material selected from among them, the shape is formed. This can be achieved. As guest materials, luminescent organic materials that exhibit fluorescence or phosphorescence can be used. It can be used. Furthermore, the configuration of the light-emitting layer shown in Embodiment 1 and Embodiment 2 can be used. It is preferable to do so. Alternatively, the light-emitting layer 190 may have a two-layer configuration. In that case, 2 Preferably, the light-emitting layers of each layer have light-emitting materials that exhibit different light-emitting colors from one another.

[0428] The electron transport layer 113 can be formed by depositing a material with high electron transport properties. It is possible. Furthermore, the electron injection layer 114 is formed by depositing a material with high electron injection properties. It is possible.

[0429] As the charge generation layer 115, electron acceptors are added to a hole transport material. Deposition of a material, or a material to which an electron donor has been added to an electron transport material. It can be formed by [this method].

[0430] ≪Step 5≫ The fifth step involves a hole injection layer 116, a hole transport layer 117, a light-emitting layer 170, and an electron transport layer. This is a step in which 118, the electron injection layer 119, and the electrode 102 are formed (see Figure 9(B)).

[0431] The hole injection layer 116 is made of the same material and is made using the same method as the hole injection layer 111 described above. It can be formed more easily. Also, as the hole transport layer 117, the hole transport layer 11 shown above It can be formed using the same materials and methods as in 2.

[0432] The light-emitting layer 170 can be purple, blue, blue-green, green, yellow-green, yellow, orange, or red. By depositing at least one luminescent guest material selected from among them, the shape is formed. This can be achieved. As guest materials, luminescent organic compounds that exhibit fluorescence or phosphorescence can be used. It can be used. Also, the configuration of the light-emitting layer shown in Embodiment 1 and Embodiment 2 can be used. It is preferable that at least one of the light-emitting layer 170 and the light-emitting layer 190 is It is preferable to have the configuration of the light-emitting layer shown in Embodiment 1. Also, light-emitting layer 170 and light-emitting layer 1 It is preferable that 90 has luminescent organic compounds that exhibit different types of luminescence from each other. .

[0433] The electron transport layer 118 is made of the same material and is constructed using the same method as the electron transport layer 113 described above. It can be formed more easily. Also, as the electron injection layer 119, the electron injection layer 11 shown above It can be formed using the same materials and methods as in 4.

[0434] The electrode 102 consists of a reflective conductive film and a translucent conductive film laminated together. It can be formed as follows. Also, the electrode 102 can be a single-layer structure or a multi-layer structure. That's good too.

[0435] After the above process, regions 222 are formed on electrodes 101, 103, and 104, respectively. A light-emitting element having region B, region 222G, and region 222R is formed on the substrate 200.

[0436] Step 6 The sixth step is to place a light-shielding layer 223, optical element 224B, and optical element 224 on the substrate 220. This is the process of forming G and the optical element 224R (see Figure 9(C)).

[0437] As the light-shielding layer 223, a resin film containing black pigment is formed in the desired area. After that, the base On the plate 220 and the light-shielding layer 223, optical element 224B, optical element 224G, and optical element 2 Forming 24R. As the optical element 224B, a resin film containing blue pigment is applied to the desired region. Formed. In addition, as the optical element 224G, a resin film containing green pigment is formed in a desired region. Furthermore, as the optical element 224R, a resin film containing red pigment is formed in the desired region. do.

[0438] ≪Step 7≫ The seventh step is to have a light-emitting element formed on substrate 200 and a light-emitting element formed on substrate 220 The light-shielding layer 223, optical element 224B, optical element 224G, and optical element 224R are attached. This is the process of sealing the parts together using a sealing material (not shown in the diagram).

[0439] By following the above steps, the light-emitting element 262a shown in Figure 7(A) can be formed.

[0440] The configuration shown in this embodiment may be used in appropriate combination with the configurations shown in other embodiments. It is possible to be there.

[0441] (Embodiment 4) In this embodiment, a display device according to one aspect of the present invention will be described using Figures 10 to 18. I will reveal it.

[0442] <Example of display device configuration 1> Figure 10(A) is a top view showing the display device 600, and Figure 10(B) is the same as Figure 10(A) but with a dashed line. This is a cross-sectional view taken along lines AB and the dashed line CD. The display device 600 includes a drive circuit section ( It has a signal line driving circuit section 601, a scan line driving circuit section 603, and a pixel section 602. Furthermore, the signal line drive circuit section 601, the scan line drive circuit section 603, and the pixel section 602 emit light. It has a function to control the light emission of the element.

[0443] Furthermore, the display device 600 includes an element substrate 610, a sealing substrate 604, and a sealing material 605. The area 607 surrounded by the sealing material 605, the routed wiring 608, and the FPC 609 are all included. do.

[0444] Furthermore, the routing wiring 608 is connected to the signal line drive circuit section 601 and the scan line drive circuit section 603. This is wiring for transmitting input signals, and it connects to the FPC609, which is an external input terminal, for video input. It receives signals such as the O signal, clock signal, start signal, and reset signal. Note that here it is FP Only C609 is shown in the diagram, but FPC609 is a printed circuit board (PWB: Pri A wired wiring board may be attached.

[0445] Furthermore, the signal line drive circuit section 601 consists of an N-channel type transistor 623 and a P-channel type A CMOS circuit is formed by combining it with transistor 624. The path section 601 or the scan line drive circuit section 603 includes various CMOS circuits, PMOS circuits, and An NMOS circuit can be used. In addition, in this embodiment, the drive circuit section is mounted on the substrate. The image shows a display device in which the formed driver and pixels are arranged on the same surface, but this is not necessarily required. Alternatively, the drive circuit can be formed externally instead of on the circuit board.

[0446] Furthermore, the pixel section 602 includes a switching transistor 611 and a current control transistor. The lower part electrically connected to the drain of transistor 612 for current control and transistor 612 It has an electrode 613. A partition wall 614 is formed to cover the end of the lower electrode 613. A positive-type photosensitive acrylic resin film can be used as the partition wall 614.

[0447] Furthermore, in order to improve coverage, the upper or lower end of the partition wall 614 has a curved surface with curvature. To ensure that a structure is formed. For example, positive-type photosensitive acrylic is used as the material for the partition wall 614. If so, the upper end of the partition wall 614 will have a curve with a radius of curvature (0.2 μm or more and 3 μm or less). It is preferable to give it a surface. Also, as the partition wall 614, a negative type photosensitive resin or a poly Any type of photosensitive resin can be used.

[0448] Furthermore, the structure of the transistors (transistors 611, 612, 623, 624) is particularly... It is not limited. For example, a staggered transistor may be used. Also, the transistor There are no particular limitations regarding polarity, and it includes N-channel and P-channel transistors. A structure that includes either an N-channel transistor or a P-channel transistor. A structure consisting of only one of the two may also be used. Furthermore, the semiconductor film crystal used in transistors... There are no particular limitations regarding properties. For example, amorphous semiconductor films and crystalline semiconductor films can be used. Yes, it is possible. Also, as semiconductor materials, there are Group 14 (silicon, etc.) semiconductors and compound semiconductors (oxides). Semiconductors (including organic semiconductors), etc., can be used. Examples of transistors include: Energy gap of 2 eV or more, preferably 2.5 eV or more, more preferably 3 eV By using the above oxide semiconductors, the off-current of the transistor can be reduced. Preferably, the oxide semiconductor is In-Ga oxide, In-M-Zn oxide (M is Aluminum (Al), gallium (Ga), yttrium (Y), zirconium (Zr ), lanthanum (La), cerium (Ce), tin (Sn), hafnium (Hf), or ne Examples include odymium (Nd).

[0449] An EL layer 616 and an upper electrode 617 are formed on the lower electrode 613, respectively. The lower electrode 613 functions as the anode, and the upper electrode 617 functions as the cathode. ru.

[0450] Furthermore, the EL layer 616 can be coated using a deposition method with a deposition mask, an inkjet method, or a spin coat. It is formed by various methods such as the law. In addition, the material that constitutes the EL layer 616 is low It may be a molecular compound or a polymeric compound (including oligomers and dendrimers).

[0451] Furthermore, the lower electrode 613, the EL layer 616, and the upper electrode 617 contribute to the light-emitting element 618. The light-emitting element 618 is formed. The light-emitting element 618 has the configuration of Embodiments 1 to 3. It is preferable that this is the case. Note that if multiple light-emitting elements are formed in the pixel portion, then Embodiments 1 to This includes both the light-emitting element described in Embodiment 3 and light-emitting elements having other configurations. You can.

[0452] Furthermore, by bonding the sealing substrate 604 to the element substrate 610 with the sealing material 605, A light-emitting element is placed in the region 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealing material 605. The structure is equipped with child 618. Furthermore, the area 607 is filled with filler material. In addition to cases where an inert gas (such as nitrogen or argon) is filled, it is also used in sealant 605. In some cases, it may be filled with UV-curing resin or thermosetting resin, for example, PVC ( Polyvinyl chloride resins, acrylic resins, polyimide resins, epoxy resins, Silicone resin, PVB (polyvinyl butyral) resin, or EVA (ethylene vinyl A resin (such as a luacetate) can be used. A recess is formed in the sealing substrate, and a desiccant is placed therein. Providing this feature can suppress deterioration due to moisture, making it a desirable configuration.

[0453] Furthermore, the optical element 621 is positioned below the sealing substrate 604 so as to overlap with the light-emitting element 618. It is provided therein. Furthermore, a light-shielding layer 622 is provided below the sealing substrate 604. Optical element 621 and the light-shielding layer 622 are the optical element and the light-shielding layer shown in Embodiment 3, respectively. A similar configuration would suffice.

[0454] Furthermore, it is preferable to use epoxy resin or glass frit for the sealant 605. Furthermore, it is desirable that these materials be as impermeable to moisture and oxygen as possible. In addition, as materials used for the sealing substrate 604, glass substrates and quartz substrates are also available, as well as FRP (Fiber Reinforced Plastic). Reinforced Plastics), PVF (Polyvinyl Fluoride), Poly A plastic substrate made of ester or acrylic can be used.

[0455] As described above, the light-emitting element and optical element described in Embodiments 1 to 3 are A display device can be obtained.

[0456] <Example of display device configuration 2> Next, another example of a display device will be explained using Figures 11(A)(B) and 12. Figures 11(A)(B) and 12 are cross-sectional views of a display device according to one embodiment of the present invention. .

[0457] Figure 11(A) shows the substrate 1001, the underlayer insulating film 1002, the gate insulating film 1003, and the gate Electrodes 1006, 1007, 1008, first interlayer insulating film 1020, second interlayer insulating film 10 21, peripheral portion 1042, pixel portion 1040, drive circuit portion 1041, lower electrode 10 of light-emitting element 24R, 1024G, 1024B, partition wall 1025, EL layer 1028, upper electrode of light-emitting element 1026, the sealing layer 1029, the sealing substrate 1031, the sealing material 1032, etc. are shown in the diagram. .

[0458] Furthermore, in Figure 11(A), as an example of an optical element, a colored layer (red colored layer 1034R) is shown. A green colored layer 1034G and a blue colored layer 1034B are provided on a transparent substrate 1033. A light-shielding layer 1035 may also be provided. A transparent material having a colored layer and a light-shielding layer. The substrate 1033 is aligned and fixed to the substrate 1001. Note that the colored layer and the light-shielding layer are also included. It is covered with an overcoat layer 1036. Also, in Figure 11(A), the colored layer Since light passing through it is red, green, and...

Claims

[Claim 1] A light-emitting element comprising a first material and a second material, The LUMO level of the first material is higher than the LUMO level of the second material. The HOMO level of the first material is lower than the HOMO level of the second material. The first material is a light-emitting element that has the function of converting triplet excitation energy into light emission.

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