Organic compounds and organic light-emitting elements

Abstract

This invention provides an organic compound with a small singlet-triplet energy difference ΔEST and a low sublimation temperature. [Solution] The organic compound is represented by the following general formula (1) and is characterized by having the following general formula (2-1) or (2-2) as a substituent. TIFF2026132601000046.tif3877

Description

Technical Field

[0001] The present invention relates to an organic compound, an organic light-emitting device using the same, and a device provided with the organic light-emitting device.

Background Art

[0002] An organic light-emitting device (hereinafter sometimes referred to as an "organic electroluminescence device" or an "organic EL device") is an electronic device having a first electrode, a second electrode, and an organic compound layer disposed between these electrodes. By injecting electrons and holes from these pair of electrodes, excitons of a light-emitting organic compound in the organic compound layer are generated, and when the excitons return to the ground state, the organic EL device emits light. A delayed fluorescence material (TADF material) generally has a structure in which a donor site and an acceptor site are bonded (hereinafter referred to as "DA type"). The DA-type TADF material is a material that emits fluorescence when returning from the excited singlet state to the ground state after causing reverse intersystem crossing (RISC) from the excited triplet state to the excited singlet state in the excited state. That is, in the TADF material, not only the excited singlet state but also the excited triplet state can be used for fluorescence emission through the path of reverse intersystem crossing, so that higher luminous efficiency can be obtained compared with ordinary fluorescent materials. After such a principle was clarified, various TADF materials have been discovered through various studies. Patent Document 1 describes a compound A having the following structure.

[0003]

Chemical formula

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Although compound A described in Patent Document 1 has a small singlet-triplet energy difference ΔEST, its high molecular weight of 1087 means that its sublimation temperature is high, and therefore, it is predicted that there is a high risk of decomposition by sublimation. This invention has been made in view of the above problems, and aims to provide an organic compound with a small ΔEST and a low sublimation temperature. [Means for solving the problem]

[0006] An organic compound characterized by being represented by the following general formula (1).

[0007] [ka] [In the above general formula (1), A is a group represented by the following general formula (2-1) or (2-2). R1 is a group represented by the following general formula (3) or (4-1). R2 is one of the following: a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a group represented by the following general formula (2-1) or (2-2). R3 is either a hydrogen atom or a group represented by the following general formula (3). However, when R2 is a group represented by the following general formula (2-1) or (2-2), R1 is a group represented by the following general formula (3) or (4-1), and R3 is a hydrogen atom. Furthermore, when R2 is an alkyl group, an aryl group, or a heteroaryl group, R1 is a group represented by the following general formula (3), and R3 is a hydrogen atom or a group represented by the following general formula (3). R4 and R5 are independently a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group, respectively.

[0008] [ka] In the general formulas (2-1) and (2-2), R6 is a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. In the general formula (3), R7 to R are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group. In the general formula (3), R 11 to R 14 Among them, one of R 11 and R 12 , R 12 and R 13 , R 13 and R 14 may be bonded to * in the following general formula (4-2).

[0009]

Chemical formula

Effect of the Invention

[0010] According to the present invention, an organic compound having a small ΔEST and a low sublimation temperature can be provided.

Brief Description of the Drawings

[0011] [Figure 1] ]](a) is a schematic cross-sectional view showing an example of a pixel of a display device according to an embodiment of the present invention. (b) is a schematic cross-sectional view of an example of a display device using an organic EL element according to an embodiment of the present invention. [Figure 2] ​This is a schematic diagram illustrating an example of a display device according to one embodiment of the present invention. [Figure 3] (a) A schematic diagram showing an example of an imaging device according to one embodiment of the present invention. (b) A schematic diagram showing an example of an electronic device according to one embodiment of the present invention. [Figure 4] (a) A schematic diagram showing an example of a display device according to one embodiment of the present invention. (b) A schematic diagram showing an example of a foldable display device. [Figure 5] (a) A schematic diagram showing an example of a lighting device according to one embodiment of the present invention. (b) A schematic diagram showing an example of an automobile having a vehicle light fixture according to one embodiment of the present invention. [Figure 6] (a) A schematic diagram showing an example of a wearable device according to one embodiment of the present invention. (b) A schematic diagram showing an example of a wearable device according to one embodiment of the present invention, which includes an imaging device. [Figure 7] (a) A schematic diagram showing an example of an image forming apparatus according to one embodiment of the present invention. (b) A schematic diagram showing an example of an exposure light source for an image forming apparatus according to one embodiment of the present invention. (c) A schematic diagram showing an example of an exposure light source for an image forming apparatus according to one embodiment of the present invention. [Modes for carrying out the invention]

[0012] The organic compound of the present invention is a compound used in organic light-emitting devices and is characterized by having a specific structure. Its structure is described in detail below. In this specification, halogen atoms include, but are not limited to, fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0013] The alkyl group preferably has 1 to 40 carbon atoms, more preferably 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and most preferably 1 to 4 carbon atoms. Specifically, examples include, but are not limited to, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, s-butyl group, pentyl group, hexyl group, octyl group, cyclohexyl group, t-pentyl group, 3-methylpentan-3-yl group, etc.

[0014] The aryl group preferably has 6 to 20 carbon atoms, more preferably 6 to 18 carbon atoms, even more preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. Specifically, examples include, but are not limited to, phenyl, naphthyl, indenyl, biphenyl, terphenyl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, anthracenyl, perilenyl, chrysenyl, and fluoranthenyl groups.

[0015] The heterocyclic group preferably has 3 to 24 carbon atoms, more preferably 3 to 18 carbon atoms, even more preferably 3 to 12 carbon atoms, and most preferably 5 to 12 carbon atoms. Specifically, examples include, but are not limited to, pyridyl, pyrimidyl, pyrazyl, triazyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazolyl, acridinyl, and phenanthrolyl groups.

[0016] The amino group is preferably a substituted amino group that is substituted with an alkyl group or an aryl group, and more preferably a substituted amino group that is substituted with an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. Specifically, examples include, but are not limited to, N-methylamino group, N-ethylamino group, N,N-dimethylamino group, N,N-diethylamino group, N-methyl-N-ethylamino group, N-benzylamino group, N-methyl-N-benzylamino group, N,N-dibenzyloamino group, anilino group, N,N-diphenylamino group, N,N-dinaphthylamino group, N,N-difluorenylamino group, N-phenyl-N-tolylamino group, N,N-ditolylamino group, N-methyl-N-phenylamino group, N,N-dianisorylamino group, N-mesityl-N-phenylamino group, N,N-dimesitylamino group, N-phenyl-N-(4-t-ributylphenyl)amino group, N-phenyl-N-(4-trifluoromethylphenyl)amino group, N-piperidyl group, etc.

[0017] The alkoxy group preferably has 1 to 40 carbon atoms, more preferably 1 to 20 carbon atoms, even more preferably 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and most preferably 1 to 4 carbon atoms. Specifically, examples include, but are not limited to, methoxy groups, ethoxy groups, propoxy groups, 2-ethyl-octyloxy groups, and benzyloxy groups.

[0018] Examples of aryloxy groups include, but are not limited to, phenoxy groups.

[0019] Examples of heteroaryloxy groups include, but are not limited to, thienyloxy groups.

[0020] A silyl group is a group in which a silicon atom has a substituent. The substituent may be a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. The substituted or unsubstituted alkyl group on the silicon atom may be a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms. The substituted or unsubstituted aryl group on the silicon atom may be a substituted or unsubstituted aryl group having 6 to 10 carbon atoms. The silyl group may be a trialkylsilyl group or a triarylsilyl group. Specifically, examples include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0021] The alkyl groups, aryl groups, heterocyclic groups, amino groups, alkoxy groups, aryloxy groups, heteroaryloxy groups, and silyl groups may further contain, but are not limited to, halogen atoms such as fluorine, chlorine, bromine, and iodine; alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and t-butyl groups; alkoxy groups such as methoxy, ethoxy, and propoxy groups; amino groups such as dimethylamino, diethylamino, dibenzylamino, diphenylamino, and ditolylamino groups; aryloxy groups such as phenoxy groups; aryl groups such as phenyl and biphenyl groups; heterocyclic groups such as pyridyl and pyrrolyl groups; and cyano groups.

[0022] [Organic compounds] First, the organic compound according to this embodiment will be described. The organic compound according to this embodiment is an organic compound represented by the following general formula (1). The isotopes of hydrogen atoms present in the molecule of the organic compound according to this embodiment are not particularly limited; for example, all hydrogen atoms in the molecule may be 1H, or some or all may be 2H (deuterium). The organic compound according to this embodiment is preferably a compound that exhibits delayed fluorescence, and is preferably a compound that exhibits thermally activated delayed fluorescence (TADF).

[0023] [ka]

[0024] A is independently selected from the groups represented by the following general formulas (2-1) or (2-2).

[0025] [ka]

[0026] Of the above general formulas (2-1) and (2-2), case (2-1) is preferred because it results in a smaller ΔEST.

[0027] <R1、R2、R3> R1 is a group represented by the following general formula (3) or (4-1).

[0028] [ka]

[0029] In the above general formula (3), R 11 ~R 14 Of these, R 11 and R 12 , R 12 and R 13 , R 13 and R 14 One of them may be combined with * in the following general formula (4-2). More preferably, in the above general formula (4-1), R 15 ~R 18 Of these, R 15 and R 16 , R 16 and R 17 , or R 17 and R 18 One of them is bonded to * in the general formula (4-2) below, and the others are hydrogen atoms.

[0030] [ka]

[0031] R2 is either a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a group represented by the following general formula (2-1) or (2-2).

[0032] R3 is either a hydrogen atom or a group represented by the above general formula (3).

[0033] However, when R2 is a group represented by the general formula (2-1) or (2-2), R1 is a group represented by the general formula (3) or (4-1), and R3 is a hydrogen atom.

[0034] Also, when R2 is any of an alkyl group, an aryl group, and a heteroaryl group, and R1 is represented by the general formula (3), R3 is either a hydrogen atom or represented by the general formula (3).

[0035] When R1 and R3 are of the general formula (3), from the perspective of molecular weight, it is preferably any of the groups represented by the following structural formulas.

[0036]

Chemical formula

[0037] <R4, R5, R6> In the general formula (1) and the general formula (2), R4 to R6 are each independently substituted with a substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted heteroaryl group. When R4 to R6 are an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 or more and 12 or less carbon atoms, the molecular weight of the organic compound according to this embodiment is low, and thus the sublimation property is excellent, which is preferable. It is more preferable that R4 to R6 are an aryl group having 6 or more and 12 or less carbon atoms, still more preferable that they are an aryl group having 6 or more and 10 or less carbon atoms, and particularly preferable that they are a phenyl group.

[0038] <R7 to R 14 > In the general formula (3), R7 to R 14 Each of these is independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group. R7 to R 14 Preferably, the group is a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, a substituted or unsubstituted heteroaryl group having 6 to 12 carbon atoms, or a cyano group.

[0039] R4 or R 14 From the viewpoint of sublimation properties, the group is preferably a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, a substituted or unsubstituted aryl group having 6 to 14 carbon atoms, or a substituted or unsubstituted heteroaryl group having 6 to 12 carbon atoms, and more preferably one of the groups represented by the following structural formula. In the following structural formula, * indicates the bond position.

[0040] [ka]

[0041] Furthermore, when R2 is an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 carbon atoms, the molecular weight of the organic compound according to this embodiment becomes lower, resulting in excellent sublimation properties, which is preferable. More preferably, R2 is a methyl group, a t-butyl group, or a phenyl group. In general formula (3), R 11 ~R 14 Of the two adjacent elements, one can be combined with (4-2). The two adjacent elements are R 11 and R 12 , R 12 and R 13 , R 13 and R 14 In particular, R 11 and R 12 When coupled, it has excellent element lifetime. Therefore, from the viewpoint of element lifetime, * in (4-2) is R 11 and R 12 It is preferable that it be bonded to.

[0042] <R 15 ~R 18 > In general formula (4-1), R 15 ~R 18 Of the two adjacent atoms, one bonds with (4-2), and the other is replaced by a hydrogen atom. The two adjacent atoms are R 15 and R 16 , R 16 and R 17 , R 17 and R 18 In particular, R 17 and R 18 When coupled, it has excellent element lifetime. Therefore, from the viewpoint of element lifetime, * in (4-2) is R 17 and R 18 It is preferable that it be bonded to.

[0043] <x> In general formula (4-2), X is selected from oxygen, sulfur, selenium, and tellurium atoms. X is preferably an oxygen atom or a sulfur atom, and more preferably an oxygen atom.

[0044] <a、b、c、d> In general formula (2), a, b, c, and d indicate the bonding positions with general formula (1). In general formula (4-2), * indicates the bonding position with general formula (4-1).

[0045] [Structural characteristics of organic compounds] The organic compound of this embodiment has the following four characteristics. (a) Because the molecular weight of the skeleton represented by general formulas (2-1) and (2-2) is low, the sublimation temperature can be lowered. (b) In the pyridine skeletons of general formulas (2-1) and (2-2), the presence of a cyano group at the ortho position relative to the bond position with general formula (1) results in a twisted arrangement of general formula (1) and general formula (2-1) or (2-2). (c) By introducing many substituents to the central benzene ring of general formula (1), the bond angles of the donor (carbazole) and acceptor (benzene) are arranged in a twisted manner. (d) In the general formula (5) below, Y is replaced with an N atom or a CH group. Furthermore, the ortho position R of the N atom is replaced with an alkyl group or an aryl group to improve the stability of the molecule.

[0046] [ka]

[0047] The following describes the characteristics of (a) through (d) above. (a) Because the molecular weight of the skeleton represented by general formula (2) is low, the sublimation temperature can be lowered. Generally, molecules with high molecular weight and strong intermolecular interactions are known to have high sublimation temperatures because of the energy required to sublimate their molecular weight and interactions. In the material shown in general formula (5), the bulky substituents are twisted and substituted around the central benzene ring, which inhibits intermolecular interactions. That is, because the intermolecular interactions are weak, the sublimation temperature is lower than that of compounds with the same molecular weight. Furthermore, a lower molecular weight results in a lower sublimation temperature. For this reason, the organic compound in this embodiment preferably has a molecular weight of 950 or less.

[0048] (b) In the pyridine skeletons of general formulas (2-1) and (2-2), the presence of a cyano group at the ortho position relative to the bond position with general formula (1) results in a twisted arrangement of general formula (1) and general formula (2-1) or (2-2). The cyano group inhibits the rotation of the cyanopyridine ring, resulting in the cyanopyridine ring being twisted relative to the central benzene ring. The twisted arrangement of the cyanopyridine ring allows the donor and acceptor to be twisted even when hydrogen is introduced to R3 to lower the molecular weight. In other words, the bond angle between the donor and acceptor becomes larger. As a result, orbital infiltration into the central benzene ring can be reduced. This improves HOMO-LUMO separation and reduces ΔEST (the difference between the lowest excited singlet energy and the lowest excited triplet energy). A calculated ΔEST of 0.1 eV or less is preferable. Note that HOMO is the highest occupied orbital and LUMO is the lowest unoccupied orbital.

[0049] (c) By introducing many central benzene substituents, the bond angles between the donor (carbazole) and acceptor (benzene) are twisted. By introducing multiple substituents (R1 to R3) to the central benzene ring shown in general formula (5), the bond angles between the donor (carbazole) and acceptor (benzene) can be twisted. As a result, orbital infiltration into the central benzene ring can be reduced. Therefore, HOMO-LUMO separation is improved and ΔEST becomes smaller. A calculated ΔEST of 0.1 eV or less is preferable. In particular, a low molecular weight can be maintained by introducing an alkyl or aryl group with a molecular weight of 200 or less to R2. From the viewpoint of reducing molecular weight, it is more preferable that R2 is substituted with a substituent (alkyl or aryl group) with a molecular weight of 100 or less.

[0050] (d) In general formula (5), Y is replaced with an N atom or a CH group. Furthermore, the ortho position R of the N atom is replaced with an alkyl group or an aryl group to improve molecular stability. Generally, the α-position of the nitrogen atom in a pyridine ring is known to have a high electron density and low molecular stability. Therefore, introducing a substituent at the α-position lowers the electron density at that position. As a result, the reactivity of the molecule decreases and its stability improves, thus improving the device lifetime.

[0051] Examples of compounds according to the present invention are shown below. The molecular weight and ΔEST calculation results for each compound are shown in Table 1.

[0052] (How to calculate ΔEST) The ΔEST between each level is determined by performing a structural optimization calculation to find the most stable structure of the ground state S0 using a density functional theory with the functional CAM-B3LYP and the basis set 6-31g**. The excitation energy E from S0 to S1 is then calculated for the most stable structure of S0 using the aforementioned functional and basis set time-dependent density functional theory. S1 Excitation energy E from S0 to T1 T1 We find that ΔEST for T1 is E S1 -E T1 This can be determined by [method].

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056] [Table 1]

[0057] Table 1 shows that the organic compound according to this embodiment can achieve both a reduction in molecular weight and a narrowing of ΔEST compared to the organic compound according to the comparative example described later. This is because the organic compound according to this embodiment has the characteristics of (a) to (c) described above, and can efficiently separate the orbital distributions of HOMO and LUMO.

[0058] [Organic light-emitting element] Next, the organic light-emitting element of this embodiment will be described. The organic light-emitting element of this embodiment has at least a first electrode, a second electrode, and an organic compound layer disposed between these electrodes. One of the first electrode and the second electrode is the anode and the other is the cathode. In the organic light-emitting element of this embodiment, the organic compound layer may be a single layer or a laminate consisting of multiple layers, as long as it has a light-emitting layer. If the organic compound layer is a laminate consisting of multiple layers, the organic compound layer may have a hole injection layer, a hole transport layer, an electron blocking layer, a hole / exciton blocking layer, an electron transport layer, an electron injection layer, etc., in addition to the light-emitting layer. The light-emitting layer may be a single layer or a laminate consisting of multiple layers.

[0059] In the organic light-emitting element of this embodiment, at least one layer of the organic compound layer contains the organic compound according to this embodiment. Specifically, the organic compound according to this embodiment is included in any of the above-mentioned light-emitting layer, hole injection layer, hole transport layer, electron blocking layer, hole / exciton blocking layer, electron transport layer, electron injection layer, etc. The organic compound according to this embodiment is preferably included in the light-emitting layer.

[0060] In the organic light-emitting device of this embodiment, if the organic compound according to this embodiment is included in the light-emitting layer, the light-emitting layer may consist only of the organic compound according to this embodiment, or it may consist of the organic compound according to this embodiment and other compounds such as a second organic compound, a third organic compound, etc. In the light-emitting layer, the organic compound of this embodiment may be used as a guest and doped into the host material (second organic compound), or it may be used as an assist dopant and doped into the host material (second organic compound) together with a fluorescent material (third organic compound).

[0061] In the doped type, the host is the compound with the largest mass ratio among the compounds that make up the light-emitting layer. The guest is the compound with a smaller mass ratio than the host among the compounds that make up the light-emitting layer, and is responsible for the primary light emission. The assist dopant is the compound with a smaller mass ratio than the host among the compounds that make up the light-emitting layer, and plays the role of sensitizing excitons.

[0062] When the organic compound of this embodiment is used as a guest, the concentration of the organic compound of this embodiment is preferably 0.01% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 50% by mass or less, relative to the entire light-emitting layer. When the organic compound of this embodiment is used as an assist dopant, the concentration of the organic compound of this embodiment is preferably 1% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 50% by mass or less, relative to the entire light-emitting layer. In this case, the concentration of the fluorescent material is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.01% by mass or more and 5% by mass or less, relative to the entire light-emitting layer.

[0063] The inventors have conducted various studies and found that when the organic compound according to this embodiment is used as a host or guest for the light-emitting layer, particularly as a guest for the light-emitting layer, a device can be obtained that exhibits high efficiency, high brightness, and extremely high durability. This light-emitting layer may be a single layer or a multi-layer, and it is also possible to mix the light-emitting color with that of the organic compound of this embodiment by including a light-emitting material having another light-emitting color. A multi-layer means a state in which one light-emitting layer and another light-emitting layer are stacked. In this case, the light-emitting color of the organic light-emitting element is not limited to the light-emitting color of the organic compound of this embodiment. More specifically, it may be white or an intermediate color. In the case of white, if the other light-emitting layer is a color other than the light-emitting color of the organic compound of this embodiment, for example, if the light-emitting color of the organic compound of this embodiment is blue, it will emit green or red light. Furthermore, the film formation method can be vapor deposition or coating.

[0064] The organic compound according to this embodiment can be used as a constituent material for organic compound layers other than the light-emitting layer constituting the organic light-emitting element of this embodiment. Specifically, it may be used as a constituent material for electron transport layers, electron injection layers, hole transport layers, hole injection layers, hole blocking layers, etc. In this case, the light emission color of the organic light-emitting element is not limited to the light emission color of the organic compound according to this embodiment. More specifically, it may be white light emission or an intermediate color.

[0065] [Other compounds] In addition to the organic compounds according to this embodiment, conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host compounds, luminescent compounds, electron-injecting or electron-transporting compounds, etc., can be used together as needed. Examples of these compounds are listed below.

[0066] As hole-injection transport materials, materials with high hole mobility are preferred to facilitate hole injection from the anode and to transport the injected holes to the light-emitting layer. Furthermore, materials with a high glass transition temperature are preferred to suppress deterioration of the film quality, such as crystallization, in the organic light-emitting element. Examples of low-molecular-weight and high-molecular-weight materials with hole-injection transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. In addition, the above-mentioned hole-injection transport materials are also suitably used in electron-blocking layers. Alternatively, a mixture of polyethylenedioxythiophene and polystyrene sulfonic acid (PEDOT:PSS), which is commonly used as a hole-injection material when manufactured by coating methods, may be used. Specific examples of compounds used as hole-injection transport materials are shown below, but are not limited to these.

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] Among the hole transport materials listed, HT16-HT18 can reduce the driving voltage when used in the layer in contact with the anode. HT16 is widely used in organic light-emitting devices. HT2-HT7, HT10, HT12, and HT22-HT28 may be used in the organic compound layer adjacent to HT16. High molecular weight compounds such as hole-transporting polyphenylene vinylene (PPV), polyfluorene (PF), polyvinylcarbazole (PVK), and their derivatives may also be used. In addition, inorganic insulating layers such as SiO2 and SiN, or organosilicon polymers such as siloxanes can also be used. Furthermore, multiple materials may be used in a single organic compound layer.

[0071] Luminescent materials primarily involved in light emission include donor-acceptor type organic compounds, boron-containing complexes, indocarbazole fused ring compounds, fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, anthracene derivatives, rubrene, etc.), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organoaluminum complexes such as tris(8-quinolinolate)aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and polymer derivatives such as poly(phenylenevinylene) derivatives, poly(fluorene) derivatives, and poly(phenylene) derivatives. Furthermore, when producing a luminescent layer by coating, polymer compounds with luminescent properties are mainly used. This is because polymer compounds have high amorphous properties, making them less prone to crystallization compared to low molecular weight systems. Specific materials used include polymer compounds such as polyphenylene vinylene (PPV), polyfluorene (PF), polyvinylcarbazole (PVK), and their derivatives. Specific examples of compounds used as luminescent materials are shown below, but are not limited to these.

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] The following are specific examples of compounds used as luminescent layer hosts or luminescence assist materials contained in the luminescent layer, but of course, they are not limited to these.

[0078] [ka]

[0079] [ka]

[0080] When used with a delayed fluorescence material or phosphorescent material, the host material is preferably one whose triplet fluorescence is higher than that of the delayed fluorescence material. Preferred host materials include, but are not limited to, EM2-EM-4, EM7-EM11, and EM14-EM16.

[0081] As electron-transporting materials, any material capable of transporting electrons injected from the cathode to the light-emitting layer can be arbitrarily selected, taking into consideration the balance with the hole mobility of the hole-transporting material. Examples of materials with electron-transporting properties include oxadiazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organoaluminum complexes, and fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, chrysene derivatives, anthracene derivatives, etc.). Furthermore, the above electron-transporting materials are also suitably used in hole-blocking layers. Specific examples of compounds used as electron-transporting materials are shown below, but are of course not limited to these.

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] Electron injection materials can be arbitrarily selected from those that allow for easy electron injection from the cathode, taking into consideration the balance with hole injection properties. Organic compounds include n-type dopants and reducing dopants. Examples include alkali metal compounds such as lithium fluoride, lithium complexes such as lithium quinolinol, benzimidazolidene derivatives, imidazolidene derivatives, fluvalene derivatives, and acridine derivatives. They can also be used in combination with the above-mentioned electron transport materials.

[0086] [Configuration of organic light-emitting diodes] An organic light-emitting element is provided on a substrate by forming an insulating layer, a first electrode, an organic compound layer, and a second electrode. A protective layer, a color filter, a microlens, etc., may be provided on the second electrode. If a color filter is provided, a planarization layer may be provided between it and the protective layer. The planarization layer can be made of acrylic resin or the like. The same applies when a planarization layer is provided between the color filter and the microlens.

[0087] [substrate] Examples of substrates include quartz, glass, silicon wafers, resins, and metals. The substrate may also be equipped with switching elements such as transistors and wiring, and an insulating layer may be provided on top of them. The insulating layer can be made of any material that allows for the formation of contact holes between it and the first electrode, while ensuring insulation from wiring that is not connected. For example, resins such as polyimide, silicon oxide, and silicon nitride can be used.

[0088] [electrode] A pair of electrodes can be used. This pair consists of an anode and a cathode. When an electric field is applied in the direction of light emission from the organic light-emitting element, the electrode with the higher potential is the anode, and the other is the cathode. Alternatively, the electrode supplying holes to the light-emitting layer can be considered the anode, and the electrode supplying electrons can be considered the cathode. For the anode, materials with the largest possible work function are preferable. For example, elemental metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, or mixtures containing these, or alloys combining them, as well as metal oxides such as tin oxide, zinc oxide, indium oxide, tin-indium oxide (ITO), and zinc-indium oxide can be used. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used. These electrode materials may be used individually or in combination of two or more types. Furthermore, the anode may consist of a single layer or multiple layers.

[0089] When used as a reflective electrode, materials such as chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates thereof can be used. It is also possible to use the above materials as a reflective film without serving as an electrode. Furthermore, when used as a transparent electrode, oxide transparent conductive layers such as indium tin oxide (ITO) or indium zinc oxide can be used, but are not limited to these. Photolithography can be used to form the electrodes.

[0090] On the other hand, materials with a small work function are preferred for the cathode. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, and elemental metals or mixtures containing these, such as aluminum, titanium, manganese, silver, lead, and chromium. Alternatively, alloys combining these elemental metals can also be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials may be used individually or in combination of two or more. The cathode may also be a single-layer or multi-layer structure. Among these, silver is preferred, and a silver alloy is even more preferred to reduce silver aggregation. The alloy ratio is not important as long as silver aggregation is reduced. For example, the ratio of silver to other metals may be 1:1, 3:1, etc.

[0091] The cathode may be a top-emission element using an oxide conductive layer such as ITO, or a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but using DC and AC sputtering methods is more preferable because it provides good film coverage and makes it easier to reduce resistance.

[0092] [Organic compound layer] The organic compound layer may be formed as a single layer or as multiple layers. If there are multiple layers, they may be called a hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, or electron injection layer depending on their function. The organic compound layer is mainly composed of organic compounds, but may also contain inorganic atoms and inorganic compounds. For example, it may contain copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, etc. The organic compound layer may be placed between the first electrode and the second electrode, or it may be placed in contact with the first electrode and the second electrode.

[0093] The organic compound layer (hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) constituting the organic light-emitting element according to one embodiment of the present invention is formed by the method shown below.

[0094] The organic compound layer constituting the organic light-emitting element according to one embodiment of the present invention can be formed using a dry process such as vacuum deposition, ionization deposition, sputtering, or plasma deposition. Alternatively, instead of a dry process, a wet process can be used in which the compound is dissolved in a suitable solvent and the layer is formed by a known coating method (for example, spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, screen printing, flexographic printing, offset printing, inkjet printing, capillary coating, nozzle coating, etc.). Among these, vacuum deposition, ionization deposition, inkjet printing, and nozzle coating are suitable for manufacturing large-area organic light-emitting elements.

[0095] When forming the light-emitting layer using an organic compound with high solubility in organic solvents from the organic compounds of this embodiment, it is preferable to form it by a coating method. Examples of coating methods include spin coating, slit coating, printing, inkjet, dispensing, and spraying. Alternatively, the light-emitting layer may be formed by vacuum deposition. When layers are formed using methods such as vacuum deposition or solution coating, crystallization is less likely to occur, resulting in excellent stability over time. Furthermore, when forming films using coating methods, it is possible to combine the film with an appropriate binder resin.

[0096] Examples of the binder resins mentioned above include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, and urea resin. Furthermore, these binder resins may be used individually as homopolymers or copolymers, or as a mixture of two or more types. Additionally, known additives such as plasticizers, antioxidants, and UV absorbers may be used in combination as needed.

[0097] The thickness of each layer in an organic light-emitting device is usually preferably between 1 nm and 10 μm. In particular, the thickness of the light-emitting layer of the organic compound layer is preferably between 10 nm and 100 μm in order to obtain effective light-emitting properties.

[0098] [Protective layer] A protective layer may be provided on the second electrode. For example, by bonding glass with a desiccant to the second electrode, the intrusion of water and other substances into the organic compound layer can be reduced, thereby reducing the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the second electrode to reduce the intrusion of water and other substances into the organic compound layer. For example, after forming the second electrode, it may be transported to another chamber without breaking the vacuum and a silicon nitride film with a thickness of 2 μm may be formed by the CVD method to serve as a protective layer. A protective layer may also be provided using atomic deposition (ALD) after the film formation by the CVD method. The material of the film formed by the ALD method is not limited, but may be silicon nitride, silicon oxide, aluminum oxide, etc. Silicon nitride may be further formed on the film formed by the ALD method by the CVD method. The film formed by the ALD method may have a thinner film thickness than the film formed by the CVD method. Specifically, it may be 50% or less, or even 10% or less.

[0099] [Color Filter] A color filter may be provided on top of the protective layer. For example, a color filter that takes into account the size of the organic light-emitting element may be provided on a separate substrate and bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer as described above using photolithography technology. The color filter may be made of polymer.

[0100] [Planarization layer] A planarizing layer may be provided between the color filter and the protective layer. The planarizing layer is provided to reduce the unevenness of the layer below. It may also be called a material resin layer without limiting its purpose. The planarizing layer may be composed of an organic compound, and may be low molecular weight or high molecular weight, but high molecular weight is preferred.

[0101] The planarization layer may be provided above or below the color filter, and its constituent materials may be the same or different. Specifically, examples include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, urea resin, etc.

[0102] [Microlens] An organic light-emitting element may have optical components such as microlenses on its light-emitting side. Microlenses may be made of acrylic resin, epoxy resin, or the like. Microlenses may be used to increase the amount of light extracted from the organic light-emitting element or to control the direction of the extracted light. Microlenses may have a hemispherical shape. If they have a hemispherical shape, among the tangents tangent to the hemisphere, there is a tangent parallel to the insulating layer, and the point of contact between that tangent and the hemisphere is the vertex of the microlens. The vertex of the microlens can be similarly determined in any cross-sectional view. That is, among the tangents tangent to the semicircle of the microlens in the cross-sectional view, there is a tangent parallel to the insulating layer, and the point of contact between that tangent and the semicircle is the vertex of the microlens. Furthermore, the midpoint of a microlens can also be defined. In the cross-section of a microlens, a line segment can be imagined from the point where one arc ends to the point where another arc ends, and the midpoint of this line segment can be called the midpoint of the microlens. The cross-section used to determine the vertices and midpoints may be a cross-section perpendicular to the insulating layer.

[0103] [Opposite substrate] A counter substrate may be provided on the planarized layer. The counter substrate is called a counter substrate because it is provided in a position corresponding to the aforementioned substrate. The constituent material of the counter substrate may be the same as that of the aforementioned substrate. The counter substrate may be a second substrate if the aforementioned substrate is referred to as the first substrate.

[0104] [Pixel circuit] An organic light-emitting device having an organic light-emitting element may have a pixel circuit connected to the organic light-emitting element. The pixel circuit may be an active-matrix type that independently controls the light emission of a first light-emitting element and a second light-emitting element. The active-matrix type circuit may be voltage-programmed or current-programmed. The driving circuit has a pixel circuit for each pixel. The pixel circuit may include a light-emitting element, a transistor that controls the light emission brightness of the light-emitting element, a transistor that controls the light emission timing, a capacitor that holds the gate voltage of the transistor that controls the light emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0105] The light-emitting device has a display area and a peripheral area arranged around the display area. The display area has a pixel circuit, and the peripheral area has a display control circuit. The mobility of the transistors constituting the pixel circuit may be smaller than the mobility of the transistors constituting the display control circuit. The slope of the current-voltage characteristic of the transistors constituting the pixel circuit may be smaller than the slope of the current-voltage characteristic of the transistors constituting the display control circuit. The slope of the current-voltage characteristic can be measured by the so-called Vg-Ig characteristic. The transistors constituting the pixel circuit are transistors connected to the light-emitting element, such as the first light-emitting element.

[0106] [Pixels] An organic light-emitting device having an organic light-emitting element may have a plurality of pixels. Each pixel may have subpixels that emit light of a different color from the others. The subpixels may each have, for example, RGB light-emitting colors. A pixel emits light in a region also called the pixel aperture. The pixel aperture is preferably 15 μm or less, but may be 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc. The distance between subpixels is preferably 10 μm or less, and may be 8 μm, 7.4 μm, 6.4 μm, etc. Pixels can take on known arrangements in a plan view. For example, they may be in a stripe arrangement, delta arrangement, pentile arrangement, or Bayer arrangement. The shape of subpixels in a plan view may be any known shape. For example, rectangles, rhombuses, hexagons, etc. Of course, even if it is not a precise shape, if it is close to a rectangle, it is included in the category of rectangles. The shape of subpixels and the pixel arrangement can be used in combination.

[0107] [Applications of organic light-emitting diodes] The organic light-emitting element according to this embodiment can be used as a component of a display device or lighting device. Other applications include exposure light sources for electrophotographic image forming apparatuses, backlights for liquid crystal display devices, and light-emitting devices with a color filter in a white light source.

[0108] The display device may be an image information processing device having an image input unit for inputting image information from an area CCD, linear CCD, memory card, etc., an information processing unit for processing the input information, and a display unit for displaying the input image. The display device may have a plurality of pixels, and at least one of the plurality of pixels may have the organic light-emitting element of this embodiment and an active element such as a transistor connected to the organic light-emitting element. In this case, the substrate is a semiconductor substrate such as silicon, and the transistor may be a MOSFET formed on the substrate. The image display device has an input unit for inputting image information and a display unit for outputting an image, and the display unit has the display device of this embodiment.

[0109] Furthermore, the display unit of the imaging device or inkjet printer may have a touch panel function. The driving method for this touch panel function may be infrared, capacitive, resistive, or electromagnetic induction, and is not particularly limited. The display device may also be used as the display unit of a multifunction printer.

[0110] Next, a display device according to this embodiment will be described with reference to the drawings. Figure 1 is a schematic cross-sectional view showing an example of a display device having an organic light-emitting element and a transistor connected to the organic light-emitting element. The transistor is an example of an active element. The transistor may be a thin-film transistor (TFT).

[0111] Figure 1(a) is a schematic cross-sectional view of an example of a pixel, which is a component of the display device according to this embodiment. The pixel has sub-pixels 20. The sub-pixels are divided into 20R, 20G, and 20B based on their light emission. The light emission color may be distinguished by the wavelength emitted from the light-emitting layer, or the light emitted from the sub-pixel may be selectively transmitted or color-converted by a color filter or the like. Each sub-pixel 20 has a reflective electrode which is a first electrode 12 on an interlayer insulating layer 11, an insulating layer 13 covering the end of the first electrode 12, an organic compound layer 14 covering the first electrode 12 and the insulating layer 13, a transparent electrode which is a second electrode 15, a protective layer 16, and a color filter 17.

[0112] The interlayer insulating layer 11 may have transistors or capacitive elements arranged in the layer below or inside it. The transistor and the first electrode 12 may be electrically connected via a contact hole or the like (not shown).

[0113] The insulating layer 13 is also called a bank or pixel separation layer. It covers the edge of the first electrode 12 and is arranged to surround the first electrode 12. The portion of the insulating layer 13 that is not present is in contact with the organic compound layer 14 and becomes the light-emitting region.

[0114] The second electrode 15 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0115] The protective layer 16 reduces the penetration of moisture into the organic compound layer 14. Although the protective layer 16 is shown as a single layer, it may consist of multiple layers. Each layer may contain an inorganic compound layer and an organic compound layer.

[0116] The color filters 17 are classified into 17R, 17G, and 17B according to their color. The color filters 17 may be formed on a planarization film (not shown). Alternatively, the color filters 17 may have a resin protective layer (not shown). Alternatively, the color filters 17 may be formed on a protective layer 16. Or, they may be bonded to an opposing substrate such as a glass substrate after being provided on it.

[0117] The display device shown in Figure 1(b) comprises an organic light-emitting element 36 and a TFT 28, which is an example of a transistor. A substrate 21 made of glass, silicon, or the like is provided, with an insulating layer 22 on top of it. An active element such as the TFT 28 is placed on the insulating layer 22, and the active element has a gate electrode 23, a gate insulating film 24, and a semiconductor layer 25. The TFT 28 has a drain electrode 26 and a source electrode 27. An insulating film 29 is provided on top of the TFT 28. The anode 31 and the source electrode 27 constituting the organic light-emitting element 36 are connected via a contact hole 30 provided in the insulating film 29.

[0118] Furthermore, the method of electrical connection between the electrodes (anode 31, cathode 33) included in the organic light-emitting element 36 and the electrodes (source electrode 27, drain electrode 26) included in the TFT 28 is not limited to the configuration shown in Figure 1(b). In other words, it is sufficient if either the anode 31 or the cathode 33 is electrically connected to either the source electrode 27 or the drain electrode 26 of the TFT 28.

[0119] In the display device shown in Figure 1(b), the organic compound layer 32 is depicted as a single layer, but the organic compound layer 32 may consist of multiple layers. A first protective layer 34 and a second protective layer 35 are provided on the cathode 33 to reduce the degradation of the organic light-emitting element 36.

[0120] In the display device shown in Figure 1(b), a transistor is used as the switching element, but other switching elements such as MIM elements may be used instead.

[0121] Furthermore, the transistor used in the display device shown in Figure 1(b) is not limited to a thin-film transistor having an active layer on the insulating surface of the substrate, but may also be a transistor using a single-crystal silicon wafer. Examples of the active layer include non-single-crystal silicon such as single-crystal silicon, amorphous silicon, and microcrystalline silicon, and non-single-crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin-film transistors are also called TFT elements.

[0122] The transistors included in the display device shown in Figure 1(b) may be formed within a substrate such as a Si substrate. Here, "formed within a substrate" means that the transistors are fabricated by processing the substrate itself, such as a Si substrate. In other words, having transistors within a substrate can be seen as the substrate and transistors being formed as a single unit.

[0123] The organic light-emitting element according to this embodiment has its luminescence controlled by a TFT, which is an example of a switching element, and by providing multiple organic light-emitting elements on one surface, an image can be displayed using the luminescence of each element. The switching element according to this embodiment is not limited to a TFT, but may also be a transistor made of low-temperature polysilicon, or an active matrix driver formed on a substrate such as a Si substrate. "On the substrate" can also mean "within the substrate." Whether to provide a transistor within the substrate or to use a TFT is selected depending on the size of the display area; for example, if the size is about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

[0124] Figure 2 is a schematic diagram showing an example of a display device according to this embodiment. The display device 1000 may have a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between the upper cover 1001 and the lower cover 1009. Flexible printed circuits FPCs 1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. Transistors are printed on the circuit board 1007. The battery 1008 does not need to be provided if the display device is not a portable device, or it may be provided in a different location even if it is a portable device.

[0125] The display device according to this embodiment may have a color filter having red, green, and blue. The color filter may have the red, green, and blue elements arranged in a delta array.

[0126] The display device according to this embodiment may be used in the display unit of a mobile terminal. In that case, it may have both display and operation functions. Examples of mobile terminals include smartphones and other mobile phones, tablets, and head-mounted displays.

[0127] The display device according to this embodiment may be used in the display unit of an imaging device having an optical unit with a plurality of lenses and an image sensor that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the image sensor. Furthermore, the display unit may be a display unit exposed to the outside of the imaging device or a display unit located inside the viewfinder. The imaging device may be a digital camera or a digital video camera.

[0128] Figure 3(a) is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 has a display device according to this embodiment. The display device may display not only the image to be captured, but also environmental information, imaging instructions, etc. Environmental information may include the intensity of ambient light, the direction of ambient light, the speed at which the subject is moving, the possibility of the subject being obscured by an obstacle, etc.

[0129] Since the optimal timing for imaging is very short, it is best to display the information as quickly as possible. Therefore, a display device using the organic light-emitting element of this embodiment is used. This is because organic light-emitting elements have a fast response speed. A display device using organic light-emitting elements can be used more suitably than liquid crystal display devices, which require a fast display speed.

[0130] The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses that form an image on the image sensor housed in the housing 1104. The focus can be adjusted by adjusting the relative positions of the multiple lenses. This operation can also be performed automatically. The imaging device may also be called a photoelectric converter. The photoelectric converter may not capture images sequentially, but may include imaging methods such as detecting the difference from the previous image or extracting from an image that is always being recorded.

[0131] Figure 3(b) is a schematic diagram showing an example of an electronic device according to this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type response unit. The operation unit 1202 may also be a biometric recognition unit that recognizes a fingerprint to unlock or otherwise perform actions. An electronic device having a communication unit can also be called a communication device. The electronic device 1200 may further have a camera function by including a lens and an image sensor. Images captured by the camera function are displayed on the display unit 1201. Examples of the electronic device 1200 include smartphones and laptop computers.

[0132] Figure 4 is a schematic diagram showing an example of a display device according to this embodiment. Figure 4(a) is a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The display unit 1302 uses a light-emitting element according to this embodiment. The display device 1300 has a frame 1301 and a base 1303 that supports the display unit 1302. The base 1303 is not limited to the form shown in Figure 4(a). The lower edge of the frame 1301 may also serve as the base. In addition, the frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0133] Figure 4(b) is a schematic diagram showing another example of the display device according to this embodiment. The display device 1310 in Figure 4(b) is configured to be foldable and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 have light-emitting elements according to this embodiment. The first display unit 1311 and the second display unit 1312 may be a single display device without seams. The first display unit 1311 and the second display unit 1312 can be separated at the bending point. The first display unit 1311 and the second display unit 1312 may each display different images, or the first and second display units may together display a single image.

[0134] Figure 5(a) is a schematic diagram showing an example of a lighting device according to this embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, and an optical filter 1404 and a light diffusion unit 1405 that transmit light emitted from the light source 1402. The light source 1402 has an organic light-emitting element according to this embodiment. The optical filter 1404 may be a filter that improves the color rendering of the light source. The light diffusion unit 1405 can effectively diffuse the light from the light source, such as for lighting up, and deliver light over a wide area. The optical filter 1404 and the light diffusion unit 1405 may be provided on the light-emitting side of the lighting. A cover may be provided on the outermost part as needed.

[0135] The lighting device is, for example, a device for illuminating a room. The lighting device may emit white light, daylight white light, or any other color from blue to red. It may have a dimming circuit to adjust the brightness and a color tuning circuit to adjust the color of the emitted light. The lighting device has the organic light-emitting element of this embodiment and a power supply circuit connected thereto. The power supply circuit is a circuit that converts AC voltage to DC voltage. The lighting device may also have an inverter circuit. White light has a color temperature of 4200K, and daylight white light has a color temperature of 5000K. The lighting device may also have a color filter.

[0136] Furthermore, the lighting device according to this embodiment may have a heat dissipation section. The heat dissipation section releases heat from inside the device to the outside, and examples include metals with high specific heat, liquid silicone, etc.

[0137] Figure 5(b) is a schematic diagram of an automobile, which is an example of a mobile body according to this embodiment. The automobile has a taillight, which is an example of a lighting device. The automobile 1500 may have a taillight 1501, and the taillight may be illuminated when the brakes are applied or the like.

[0138] The taillight 1501 has an organic light-emitting element according to this embodiment. The taillight 1501 may have a protective member to protect the organic light-emitting element. The protective member has a reasonably high strength and can be made of any transparent material, but it is preferably made of polycarbonate or the like. A frangic acid derivative, an acrylonitrile derivative, or the like may be mixed with the polycarbonate.

[0139] The automobile 1500 may have a body 1503 and windows 1502 attached thereto. The windows 1502 may be transparent displays, unless they are windows for checking the front and rear of the automobile. The transparent displays have organic light-emitting elements according to this embodiment. In this case, the constituent materials such as electrodes of the organic light-emitting element are made of transparent members.

[0140] The mobile body according to this embodiment may be a ship, aircraft, drone, etc. The mobile body may have a body and a lighting device provided on the body. The lighting device may emit light to indicate the position of the body. The lighting device has an organic light-emitting element according to this embodiment.

[0141] Referencing Figure 6, examples of applications of the display devices of each embodiment described above will be explained. The display device can be applied to systems that can be worn as wearable devices such as smart glasses, HMDs, and smart contact lenses. The imaging display device used in such applications comprises an imaging device capable of photoelectric conversion of visible light and a display device capable of emitting visible light.

[0142] Figure 6(a) is a schematic diagram showing an example of a wearable device according to one embodiment of the present invention. Using Figure 6(a), we will explain a pair of glasses 1600 (smart glasses) according to one application example. An imaging device 1602, such as a CMOS sensor or SPAD, is provided on the front surface side of the lens 1601 of the glasses 1600. In addition, the display devices of each embodiment described above are provided on the back surface side of the lens 1601.

[0143] The eyeglasses 1600 further include a control device 1603. The control device 1603 functions as a power supply that provides power to the imaging device 1602 and the display device. The control device 1603 also controls the operation of the imaging device 1602 and the display device. The lens 1601 has an optical system formed therein for focusing light onto the imaging device 1602.

[0144] Figure 6(b) is a schematic diagram showing another example of a wearable device according to one embodiment of the present invention. Using Figure 6(b), we will describe a pair of glasses 1610 (smart glasses) according to one application example. The glasses 1610 have a control device 1612, which is equipped with an imaging device corresponding to the imaging device 1602 in Figure 6(a) and a display device. The lens 1611 has an optical system formed therein for projecting light emitted from the imaging device and the display device in the control device 1612, and an image is projected onto the lens 1611. The control device 1612 functions as a power supply that supplies power to the imaging device and the display device, and also controls the operation of the imaging device and the display device.

[0145] The control device 1612 may have a gaze detection unit that detects the wearer's gaze. Gaze detection may use infrared light. The infrared light emitter emits infrared light towards the user's eyeball that is fixated on the displayed image. An imaging unit having a photodetector detects the reflected light from the eyeball of the emitted infrared light, thereby obtaining an image of the eyeball. By having a reduction means that reduces the light from the infrared light emitter to the display unit in a planar view, the degradation of image quality is reduced. The user's gaze toward the displayed image is detected from the image of the eyeball obtained by imaging with infrared light. Any known method can be applied to gaze detection using the image of the eyeball. As an example, a gaze detection method based on the Purkinje image obtained by the reflection of irradiated light from the cornea can be used. More specifically, gaze detection processing based on the pupil-corneal reflection method is performed. Using the pupil-corneal reflection method, the user's gaze is detected by calculating a gaze vector representing the orientation (rotation angle) of the eyeball based on the pupil image and the Purkinje image included in the image of the eyeball.

[0146] A display device according to one embodiment of the present invention includes an imaging device having a light-receiving element, and the display image of the display device may be controlled based on the user's gaze information from the imaging device. Specifically, the display device determines a first field of view area that the user is fixated on, and a second field of view area other than the first field of view area, based on the gaze information. The first and second field of view areas may be determined by the control device of the display device, or they may be determined by an external control device and received by the display device. In the display area of ​​the display device, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0147] Furthermore, the display area has a first display area and a second display area different from the first display area, and based on gaze information, a higher priority area is determined from the first display area and the second display area. The first and second view areas may be determined by the control device of the display device, or they may be determined by an external control device and received. The resolution of the higher priority area may be controlled to be higher than the resolution of the areas other than the higher priority area. In other words, the resolution of areas with relatively lower priority may be lower.

[0148] Furthermore, AI may be used to determine the primary field of view and high-priority areas. The AI ​​may be a model configured to estimate the angle of gaze and the distance to the target object at the end of the line of sight from the image of the eye, using the image of the eye and the direction the eye was actually looking in that image as training data. The AI ​​program may be installed in the display device, the imaging device, or an external device. If installed in an external device, it will be transmitted to the display device via communication.

[0149] When display control is based on visual detection, this method is preferably applicable to smart glasses that further include an imaging device for capturing images of the surrounding environment. The smart glasses can display the captured external information in real time.

[0150] Figure 7(a) is a schematic diagram showing an example of an image forming apparatus according to one embodiment of the present invention. The image forming apparatus 1700 is an electrophotographic image forming apparatus and includes a photoreceptor 1707, an exposure light source 1708, a charging unit 1710, a developing unit 1711, a transfer unit 1712, a transport roller 1713, and a fuser 1715. Light 1709 is irradiated from the exposure light source 1708, and an electrostatic latent image is formed on the surface of the photoreceptor 1707. This exposure light source 1708 has an organic light-emitting element according to this embodiment. The developing unit 1711 contains toner or the like. The charging unit 1710 charges the photoreceptor 1707. The transfer unit 1712 transfers the developed image to a recording medium 1714. The transport roller 1713 transports the recording medium 1714. The recording medium 1714 is, for example, paper. The fuser 1715 fixes the image formed on the recording medium 1714.

[0151] Figures 7(b) and 7(c) are schematic diagrams showing the exposure light source 1708, illustrating how multiple light-emitting units 1726 are arranged on a long substrate. The arrow 1727 is parallel to the axis of the photoreceptor and represents the column direction in which the organic light-emitting elements are arranged. This column direction is the same as the direction of the axis of rotation of the photoreceptor 1707. This direction can also be called the long axis direction of the photoreceptor 1707. Figure 7(b) shows a configuration in which the light-emitting units 1726 are arranged along the long axis direction of the photoreceptor 1707. Figure 7(c) is a different configuration from Figure 7(b), in which the light-emitting units 1726 are arranged alternately in the column direction in the first and second columns, respectively. The first and second columns are located at different positions in the row direction. In the first column, multiple light-emitting units 1726 are arranged at intervals. In the second column, light-emitting units 1726 are located at positions corresponding to the intervals between the light-emitting units 1726 in the first column. In other words, multiple light-emitting units 1726 are also arranged at intervals in the row direction. The arrangement in Figure 7(c) can also be described as a grid arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0152] As described above, by using the device employing the organic light-emitting element according to this embodiment, stable display with good image quality is possible even during long-term display. Furthermore, by using the device employing the organic light-emitting element according to this embodiment, it is possible to achieve both good visibility outdoors due to high-efficiency, high-brightness light output and power-saving display.

[0153] [Ink composition] Next, an ink composition according to one embodiment of the present invention will be described. The ink composition of this embodiment contains at least one of the organic compounds of this embodiment described above. The organic compound of this embodiment has good solubility in organic solvents and can therefore be used as an ink composition. Furthermore, by using the ink composition of this embodiment, the organic compound layer constituting the organic light-emitting element of this embodiment, particularly the light-emitting layer, can be fabricated by a coating method, making it possible to easily manufacture large-area elements at a relatively low cost.

[0154] Examples of solvents for dissolving the organic compounds in this embodiment include toluene, xylene, mesitylene, dioxane, methylnaphthalene, tetrahydrofuran, diglyme, 1,2-dichlorobenzene, and 1,2-dichloropropane. These organic solvents can be used individually or in combination of two or more. Among these, it is preferable to use an organic solvent with a suitable evaporation rate, specifically one with a boiling point of about 70°C to 200°C, as this makes it easier to obtain a thin film with a uniform thickness.

[0155] Furthermore, the ink composition of this embodiment may also contain other additive compounds. Examples of additive compounds include the above-mentioned known light-emitting layer host or light-emitting assist material, hole transport material, light-emitting material, electron transport material, etc.

[0156] The concentration of the organic compound of this embodiment in the ink composition is preferably 0.05% by mass or more and 20% by mass or less, and more preferably 0.1% by mass or more and 5% by mass or less, relative to the entire composition.

[0157] The ink composition of this embodiment can be formed into a film by methods such as spin coating, bar coating, slit coating, inkjet, nozzle coating, casting, and gravure printing. The organic light-emitting element of this embodiment can be used to construct a display device such as a screen by forming a layer containing the organic compound of this embodiment on electrodes formed in a pixel pattern.

[0158] [Included components] This embodiment includes the following configuration. (Composition 1) An organic compound characterized by being represented by the general formula (1) described above. (Configuration 2) The organic compound according to configuration 1, characterized in that, in the general formula (1) above, A is a group represented by the general formula (2-1) above, and R2 is an alkyl group having 1 to 4 carbon atoms. (Composition 3) In the above general formula (3), R7 to R 14 An organic compound according to configuration 1 or 2, characterized in that five or more of them are hydrogen atoms. (Composition 4) The organic compound according to any one of configurations 1 to 3, characterized in that X is either an oxygen atom or a sulfur atom in the general formula (4-2). (Composition 5) The organic compound according to configuration 4, characterized in that X is an oxygen atom. (Composition 6) In the above general formula (4-1), R 17 and R 18 An organic compound according to any one of configurations 1 to 5, characterized in that a group represented by the general formula (4-2) is bonded to it.

[0159] (Composition 7) In the above general formulas (1), (2-1), (2-2), and (3), R4 to R 14 The organic compound according to any one of configurations 1 to 6, characterized in that each of the following groups is independently selected from a hydrogen atom, a deuterium atom, and any of the groups represented by the following structural formulas.

[0160] [ka] [In the above structural formula, * indicates a bond position.] (Composition 8) The organic compound according to any one of the configurations 1 to 6, characterized in that R2 in the general formula (1) is an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 carbon atoms. (Composition 9) The organic compound according to configuration 8, characterized in that R2 is one of a methyl group, a t-butyl group, or a phenyl group.

[0161] (Composition 10) The organic compound according to any one of configurations 1 to 9, characterized in that R1 and R3 in the general formula (1) are groups represented by the general formula (3). (Composition 11) The organic compound according to configuration 10, characterized in that R1 and R3 are each independently selected from any of the groups represented by the following structural formula.

[0162] [ka]

[0163] (Composition 12) In the above general formula (4-1), R 15 ~R 18 Of these, R 15 and R 16 , R 16 and R 17 , or R 17 and R 18 An organic compound according to any one of configurations 1 to 11, characterized in that one of them is bonded to * in the general formula (4-2), and the others are hydrogen atoms. (Composition 13) An organic compound according to any one of configurations 1 to 12, characterized in that R4 and R5 in general formula (1) are aryl groups. (Composition 14) An organic compound according to any one of the configurations 1 to 13, characterized in that its molecular weight is 950 or less. (Composition 15) The organic compound according to any one of configurations 1 to 14, characterized in that the difference between the lowest excited singlet energy and the lowest excited triplet energy of the organic compound is 0.1 eV or less.

[0164] (Composition 16) An organic light-emitting element having a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode, An organic light-emitting element characterized in that at least one layer of the organic compound layer contains the organic compound described in any of configurations 1 to 15. (Composition 17) The organic light-emitting element according to configuration 16, characterized in that the layer containing the organic compound is a light-emitting layer. (Composition 18) The organic light-emitting element according to configuration 17, characterized in that the light-emitting layer has a second organic compound different from the organic compound. (Composition 19) The organic light-emitting element according to configuration 18, characterized in that the light-emitting layer has a third organic compound that is different from both the organic compound and the second organic compound.

[0165] (Composition 20) An ink composition characterized by containing an organic compound as described in any of the components 1 to 15.

[0166] (Composition 21) A display device having a plurality of pixels, wherein at least one of the plurality of pixels comprises an organic light-emitting element according to any one of configurations 16 to 19 and a transistor connected to the organic light-emitting element. (Composition 22) It comprises an optical unit having multiple lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays the image captured by the image sensor. The photoelectric conversion device is characterized in that the display unit has an organic light-emitting element as described in any of configurations 16 to 19. (Composition 23) An electronic device comprising: a display unit having an organic light-emitting element as described in any of configurations 16 to 19; a housing on which the display unit is provided; and a communication unit provided in the housing for communicating with the outside. (Composition 24) A lighting device characterized by comprising a light source having an organic light-emitting element as described in any of configurations 16 to 19, and a light-diffusing section or optical filter that transmits light emitted by the light source. (Composition 25) A mobile body characterized by comprising a lamp having an organic light-emitting element as described in any one of items 16 to 19, and a body on which the lamp is provided. (Composition 26) It comprises a photoreceptor and an exposure light source for exposing the photoreceptor, The image forming apparatus is characterized in that the exposure light source has an organic light-emitting element as described in any of configurations 16 to 19. [Examples]

[0167] Examples are described below. However, the present invention is not limited to these examples.

[0168] (Example 1) (1) Synthesis of Example Compound 1 (Example Compound 1) Example compound 1 was synthesized using the following synthesis route. Before heating and stirring the reagents and solvents in each reaction step, argon bubbling was performed for 10 minutes.

[0169] [ka]

[0170] (1-1) Synthesis of intermediate a In a flask, 3,6-dibromopicolinonitrile (3.1 g), phenylboronic acid (1.6 g), dichlorobis(triphenylphosphine)palladium(II) (0.42 g), potassium fluoride (3.8 g), acetonitrile (40 ml), and water (13 ml) were added and stirred at 70°C for 11 hours. After extraction with ethyl acetate, the mixture was dried over magnesium sulfate, and the solids were removed by filtration to concentrate the solution. Columnar purification was performed using an ethyl acetate:hexane mixture (volume ratio 3:7) as the developing solvent, yielding 1.93 g of a white powder. The peak m / z = 258.0 of intermediate 1 was confirmed by GC-MS.

[0171] (1-2) Synthesis of intermediate b 1,5-Dibromo-3-chloro-2-fluorobenzene (2.3g), bis(pinacolato)diborone (5.1g), [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride dichloromethane adduct (0.33g), potassium acetate (9.8g), and dioxane (48ml) were added and stirred at 100°C for 11 hours. After concentration under reduced pressure, hexane was added and 3.8g of a sticky substance was obtained by Celite filtration. The peak m / z = 382.2 of intermediate 2 was confirmed by GCMS. From the area ratio of other GCMS peaks, it was found that intermediate b was present in 66% of this sticky substance. This sticky substance was used as is in subsequent synthesis.

[0172] (1-3) Synthesis of intermediate c Intermediate a (0.87 g) and intermediate b (0.61 g) were mixed with tetrakistriphenylphosphine palladium (92 mg) and potassium carbonate (2.0 g), to which dioxane (20 ml) and water (5 ml) were added, and the mixture was stirred at 80°C for 11 hours. Water was added to the reaction mixture, and it was extracted with ethyl acetate. After drying over magnesium sulfate, the mixture was filtered with Celite, and the filtrate was allowed to dry. Columnar purification was performed using ethyl acetate:hexane (volume ratio 4:6) as the developing solvent to obtain 0.51 g of white powder. Further, 0.24 g was obtained by gel permeation chromatography using chloroform as the developing solvent. The peak m / z = 486.1 of intermediate c was confirmed by GC-MS.

[0173] (1-4) Synthesis of intermediate d Intermediate c (490 mg), bis(pinacolato)diborone (480 mg), palladium acetate (4.5 mg), potassium acetate (294 mg), XPhos(2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl) (19 mg) were mixed with dioxane (5 ml) and stirred at 110°C for 11 hours. Water was added to the reaction mixture, extracted with ethyl acetate, dried over magnesium sulfate, filtered by Celite, and allowed to dry under reduced pressure to obtain 490 mg of gray powder. The peak m / z = 578.2 of intermediate d was confirmed by GC-MS.

[0174] (1-5) Synthesis of intermediate e Intermediate d (310 mg), 2-chloro-4,6-diphenyl-1,3,5-triazine (155 mg), tetrakistriphenylphosphine palladium (6 mg), and potassium carbonate (220 mg) were mixed with tetrahydrofuran (12 ml) and water (4 ml), and stirred at 80°C for 11 hours. 30 ml of chloroform was added to the reaction mixture for extraction, and the mixture was dried over magnesium sulfate, filtered through Celite, and then concentrated. 20 ml of chloroform was added, followed by methanol to precipitate a white solid, and 350 mg of white powder was obtained by filtration. The peak m / z = 578.2 of intermediate e was confirmed by GC-MS.

[0175] (1-6) Synthesis of Compound 1 (Example) Intermediate e (300 mg), 5H-benzofl[3,2-c]carbazole (120 mg), and cesium carbonate (280 mg) were mixed with N,N-dimethylformamide (10 ml) and stirred at 160°C for 11 hours. Chloroform and water were added to the reaction mixture and extracted into the organic layer. This organic layer was filtered through Celite and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (solvent: toluene), methanol was added to the solution, and the precipitated solid was filtered to obtain 150 mg of pale yellow powder. The HPLC purity was 98.0%.

[0176] (2) Synthesis of Example Compound 2 (Example Compound 3) Example compound 2 was synthesized using the following synthesis route.

[0177]

Chem.

[0178] (2-1) Synthesis of Intermediate g 1-Bromo-2-fluoro-5-iodo-3-methylbenzene (5.0 g), bis(pinacolato)diboron (4.4 g), [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride (0.42 g), potassium acetate (4.7 g), and dioxane (16 ml) were added, and the mixture was stirred at 100 °C for 11 hours to obtain a reaction mixture containing Intermediate f. After cooling to room temperature, Intermediate a (4.5 g), 2M aqueous sodium carbonate solution (39.0 mL), bis(triphenylphosphine)palladium(II) dichloride (Pd(PPh3)2C l2 884 mg), and dioxane (7.9 mL) were added, and the mixture was stirred at 80 °C for 11 hours. Ethyl acetate was added to the reaction mixture, and after extraction with ethyl acetate, it was dried over sodium sulfate. The solvent was removed, and the residue was purified by column chromatography (hexane / chloroform) to obtain Intermediate g (3.6 g).

[0179] (2-2) Synthesis of Intermediate i Intermediate g (3.6 g), bis(pinacolato)diboron (3.3 g), [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride (0.30 g), potassium acetate (3.4 g), and dioxane (11 ml) were added, and the mixture was stirred at 100 °C for 11 hours to obtain a reaction mixture containing Intermediate h. After cooling to room temperature, 2-chloro-4,6-diphenyl-1,3,5-triazine (3.4 g), 2M aqueous sodium carbonate solution (28.0 mL), bis(triphenylphosphine)palladium(II) dichloride (Pd(PPh3)2Cl2, 402 mg), and THF (17 mL) were added, and the mixture was stirred at 80 °C for 11 hours. Ethyl acetate was added to the reaction mixture, and after extraction with ethyl acetate, it was dried over sodium sulfate. The solvent was removed, and the residue was purified by column chromatography (hexane / dichloromethane) to obtain Intermediate g (3.9 g).

[0180] (2 - 3) Synthesis of Example Compound 2 To intermediate 4 (1.5 g), 9H - carbazole (2.7 g), and cesium carbonate (5.6 g), DMF (19.2 mL) was added under a nitrogen atmosphere, and the mixture was stirred at 150 °C for 11 hours. After returning to room temperature, water and methanol were added to the reaction solution, and the suspension was filtered. The residue was purified by recycled preparative GPC (JAI - GEL, chloroform) to obtain Example Compound 2 (1.5 g) as a pale yellow solid.

[0181] (3) Synthesis of Example Compound 3 (Exemplary Compound 12) According to the synthesis method of Example Compound 1, Example Compound 3 was synthesized by the following reaction formula using 1,5 - dibromo - 2,4 - difluoro - 3 - methylbenzene as the starting material.

[0182]

Chemical formula

[0183] (4) Synthesis of Example Compound 4 (Exemplary Compound 14) Example Compound 4 was synthesized by the following synthetic route.

[0184]

Chemical formula

[0185] (4 - 1) Synthesis of Intermediates m to p Using 1,5 - dibromo - 2,4 - difluorobenzene as the starting material, it was synthesized according to the above synthetic route.

[0186] (4 - 2) Synthesis of Intermediate q Palladium(II) acetate (46 mg), intermediate p (1.2 g), bromobenzene (1.8 g), cesium carbonate (2.6 g), 2-ethylhexanoic acid (0.6 g), and tricyclohexylphosphine (0.17 g) were mixed with xylene (23 mL) under a nitrogen atmosphere and stirred at 130 °C for 11 hours. Chloroform was added to the reaction mixture, and the mixture was extracted with chloroform, dried over magnesium sulfate, and the solvent was removed by distillation. The residue was purified by recycled preparative GPC (JAI-GEL, chloroform) to obtain intermediate q (0.33 g).

[0187] (4-3) Synthesis of Compound 4 in Example The compound was synthesized using intermediate q according to the synthesis route of Example Compound 1.

[0188] (5) Synthesis of Example Compound 5 (Example Compound 17) Example compound 5 was synthesized using the following synthesis route.

[0189] [ka]

[0190] (5-1) Synthesis of intermediate r It was synthesized using 6-bromo-2-chloronicotinonitrile as a starting material, following the synthesis route of intermediate a.

[0191] (5-2) Synthesis of Compound 5 (Example) Example compound 5 was synthesized using intermediate r instead of intermediate a, following the synthesis route of Example compound 3.

[0192] (6) Synthesis of Example Compound 6 (Example Compound 19) Example compound 6 was synthesized using intermediate r instead of intermediate a, following the synthesis route of Example compound 4.

[0193] (7) Synthesis of Example Compound 7 (Example Compound 7) Compound 7 was synthesized according to the synthetic route of Example Compound 1 using Intermediate r instead of Intermediate a and 3-phenyl-9H-carbazole instead of 5H-benzofuro[3,2-c]carbazole.

[0194] (8) Synthesis of Example Compound 8 (Exemplary Compound 5) Example Compound 5 was synthesized according to the following synthetic route.

[0195]

Chemical formula

[0196] (8-1) Synthesis of Intermediate s Under a nitrogen atmosphere, to 1-bromo-5-chloro-2-fluoro-3-iodobenzene (5.00 g), phenylboronic acid (2.09 g), 2M aqueous sodium carbonate solution (22.4 mL), and tetrakis(triphenylphosphine)palladium(0) (1.12 g) was added toluene (75 mL), and the mixture was stirred at 80 °C for 11 hours. Ethyl acetate was added to the reaction mixture, and after extraction with ethyl acetate, it was dried over sodium sulfate. The solvent was removed, and the residue was purified by column chromatography (hexane) to obtain Intermediate s (3.41 g).

[0197] (8-2) Synthesis of Intermediates t to u It was synthesized using Intermediate s in the same manner as Intermediate i.

[0198] (8-3) Synthesis of Intermediates v to w It was synthesized using Intermediate u in the same manner as Intermediate h.

[0199] (8-4) Synthesis of Example Compound 8 It was synthesized using Intermediate w in the same manner as Example Compound 2.

[0200] (9) Synthesis of Example Compound 9 (Exemplary Compound 22) Compound 9 was synthesized according to the synthetic route of Example Compound 2 using Intermediate i and 3-phenyl-9H-carbazole.

[0201] (10) Synthesis of Example Compound 10 (Example Compound 9) Example compound 10 was synthesized using intermediate r instead of intermediate a, following the synthesis route of Example compound 2.

[0202] (11) Synthesis of Example Compound 11 (Example Compound 11) Example compound 11 was synthesized using intermediate r instead of intermediate a, following the synthesis route of Example compound 8.

[0203] (12) Synthesis of Example Compound 12 (Example Compound 15) Example compound 12 was synthesized using the following synthetic route.

[0204] [ka]

[0205] (12-1) Synthesis of intermediate x 9H-carbasol (0.17 g) and sodium hydride (50% by mass, 0.13 g) were mixed with THF (19 mL) under a nitrogen atmosphere and stirred at 0°C for 1 hour. The reaction mixture was cooled to -78°C, intermediate l (0.50 g) was added, and the mixture was stirred for 24 hours. Water was added to the reaction solution and concentrated using a rotary evaporator. The suspension was filtered, and the residue was purified by column chromatography (hexane / toluene) to obtain intermediate w (0.38 g) as a pale yellow solid.

[0206] (12-2) Synthesis of Compound 12 (Example) Example compound 12 was synthesized using intermediate w and 3-phenyl-9H-carbazole, following the synthesis route of Example compound 2.

[0207] (13) Synthesis of Example Compound 13 (Example Compound 20) Example compound 13 was synthesized by using intermediate r in place of intermediate a, following the synthesis route of Example compound 12.

[0208] (14) Example Compound 14 (Example Compound 25) Example compound 14 was synthesized using 3-phenyl-9H-carbazole instead of 9H-carbazole, following the synthesis route of Example compound 10.

[0209] (14) Synthesis of Example Compound 15 (Example Compound 8) Example compound 15 was synthesized using 5H-benzofl[3,2-c]carbazole instead of 9H-carbazole, following the synthetic route of Example compound 7.

[0210] (15) Synthesis of Comparative Compounds 1 to 3 Comparative example compound 1 was synthesized using intermediate q in the following reaction equation, following the synthesis route of example compound 3.

[0211] [ka]

[0212] Comparative compounds 2 and 3 were synthesized according to the synthesis method described in International Publication No. 2023 / 140374. Comparative examples 1 to 3 are shown below.

[0213] [ka]

[0214] (Example 2) The sublimation temperature and ΔEST of Example Compounds 1 to 15 and Comparative Compounds 1 to 3 synthesized in Example 1 were measured using the following method. Table 2 shows the molecular weight, measured ΔEST, and sublimation temperature of each compound.

[0215] [Method for measuring sublimation temperature] 2.0 mg of each compound was weighed out, and the sublimation temperature was determined by vacuum TG measurement at the temperature of 10% weight loss.

[0216] [Method for measuring ΔEST] 1.0 × 10 -5 After bubbling a toluene solution of M with Ar for 5 minutes, the fluorescence emission spectrum was measured at room temperature (298K). A tangent line was drawn to the rise of the short-wavelength side of the measured fluorescence spectrum, and the wave λF [nm] at the intersection of this tangent line and the horizontal axis was determined. From this, the excited singlet energy level S1 [eV] was calculated using the formula: excited singlet energy level [eV] = 1239.85 / λF. The sample prepared in the same manner was cooled to 77K, and the phosphorescence emission spectrum observed after the excitation light was cut off was measured. A tangent line was drawn to the rise of the short-wavelength side of the measured phosphorescence spectrum, and the wave λP [nm] at the intersection of this tangent line and the horizontal axis was determined. From this, the excited triplet energy level T1 (eV) was calculated using the formula: excited triplet energy level [eV] = 1239.85 / λP. ΔEST was calculated by subtracting T1 from S1, which was measured as described above.

[0217] [Table 2]

[0218] As shown in Table 2, Example compounds 1 to 5 have small ΔEST values, low molecular weights, and low sublimation temperatures, and their sublimation temperatures are lower compared to Comparative Examples 2 to 3.

[0219] ΔEST is smaller for the example compound than for Comparative Example 1. This indicates that it is better to substitute a substituent for R2 in general formula (1). Furthermore, comparing example compounds 3 and 5, and example compounds 8 and 11, it can be seen that ΔEST is smaller when A in general formula (1) is substituted with (2-1) than when it is substituted with (2-2). Also, comparing example compound 3 and example compound 4, the sublimation temperature is lower, so it can be seen that an alkyl group is preferable to an aryl group for R2. Based on the above, the organic compound according to the present invention can provide an organic compound with a small ΔEST and a low sublimation temperature. Furthermore, by using the organic compound according to this embodiment in an organic light-emitting element, an organic light-emitting element with excellent element durability can be provided. [Explanation of symbols]

[0220] 14,32: Organic compound layer, 18,36: Organic light-emitting element, 1000,1300,1310: Display device, 1100: Imaging device, 1104,1203,1313: Housing, 1200: Electronic equipment, 1201,1302,1311,1312: Display unit, 1707: Photoreceptor, 1708: Exposure light source< / x>

Claims

1. An organic compound characterized by being represented by the following general formula (1). 【Chemistry 1】 [In the above general formula (1), A is a group represented by the following general formula (2-1) or (2-2). R 1 This is a group represented by the following general formula (3) or (4-1). R 2 is one of the following: a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a group represented by the following general formula (2-1) or (2-2). R 3 is either a hydrogen atom or a group represented by the following general formula (3). However, R 2 When R is a group represented by the following general formula (2-1) or (2-2), 1 R is a group represented by the following general formula (3) or (4-1), 3 It is a hydrogen atom. Also, when R 2 is any one of an alkyl group, an aryl group, and a heteroaryl group, R 1 is a group represented by the following general formula (3), and R 3 is a hydrogen atom or a group represented by the following general formula (3). R 4 , R 5 Each of these is independently a substituted or unsubstituted aryl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted heteroaryl group. 【Chemistry 2】 In the above general formulas (2-1) and (2-2), R 6 These are substituted or unsubstituted alkyl groups, substituted or unsubstituted aryl groups, and substituted or unsubstituted heteroaryl groups. In the above general formula (3), R 7 ~R 14 Each of these is independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, and a cyano group. In the above general formula (3), R 11 ~R 14 Of these, R 11 and R 12 , R 12 and R 13 , R 13 and R 14 One of them may be combined with * in the following general formula (4-2). 【Transformation 3】 In the above general formula (4-2), X is selected from oxygen, sulfur, selenium, and tellurium atoms. In the above general formulas (2-1), (2-2), (3), and (4-1), a, b, c, and d indicate the bonding positions with the above general formula (1).

2. In the above general formula (1), A is a group represented by general formula (2-1), and R 2 The organic compound according to claim 1, characterized in that is an alkyl group having 1 to 4 carbon atoms.

3. In the above general formula (3), R 7 ~R 14 The organic compound according to claim 1, characterized in that five or more of them are hydrogen atoms.

4. The organic compound according to claim 1, characterized in that, in the general formula (4-2) above, X is either an oxygen atom or a sulfur atom.

5. The organic compound according to claim 4, characterized in that X is an oxygen atom.

6. In the above general formula (4-1), R 17 and R 18 The organic compound according to claim 1, characterized in that a group represented by the general formula (4-2) is bonded to it.

7. The aforementioned R 4 ~R 14 The organic compound according to claim 1, characterized in that each of the following groups is independently selected from a hydrogen atom, a deuterium atom, and any of the groups represented by the following structural formulas. 【Chemistry 4】 [In the above structural formula, * indicates the bond position.]

8. The aforementioned R 2 The organic compound according to claim 1, characterized in that it is an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 carbon atoms.

9. The aforementioned R 2 The organic compound according to claim 8, characterized in that it is one of a methyl group, a t-butyl group, or a phenyl group.

10. The aforementioned R 1 and R 3 The organic compound according to claim 1, characterized in that it is a group represented by the general formula (3) above.

11. The aforementioned R 1 and R 3 The organic compound according to claim 10, characterized in that each group is independently selected from any of the groups represented by the following structural formulas. 【Transformation 5】

12. In the above general formula (4-1), R 15 ~R 18 Of these, R 15 and R 16 , R 16 and R 17 , or R 17 and R 18 One of them is bonded to * in the general formula (4-2) above, and the others are hydrogen atoms.

13. The aforementioned R 4 and R 5 The organic compound according to claim 1, characterized in that it is an aryl group.

14. The organic compound according to claim 1, characterized in that its molecular weight is 950 or less.

15. The organic compound according to claim 1, characterized in that the difference between the lowest excited singlet energy and the lowest excited triplet energy of the organic compound is 0.1 eV or less.

16. An organic light-emitting element having a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode, An organic light-emitting element characterized in that at least one layer of the organic compound layer contains the organic compound described in any one of claims 1 to 15.

17. The organic light-emitting element according to claim 16, characterized in that the layer containing the organic compound is a light-emitting layer.

18. The organic light-emitting element according to claim 17, characterized in that the light-emitting layer has a second organic compound different from the organic compound.

19. The organic light-emitting element according to claim 18, characterized in that the light-emitting layer has a third organic compound that is different from both the organic compound and the second organic compound.

20. An ink composition characterized by containing the organic compound described in any one of claims 1 to 15.

21. A display device having a plurality of pixels, wherein at least one of the plurality of pixels is an organic light-emitting element according to claim 16 and a transistor connected to the organic light-emitting element.

22. It comprises an optical unit having multiple lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays the image captured by the image sensor. The photoelectric conversion device is characterized in that the display unit has the organic light-emitting element described in claim 16.

23. An electronic device comprising: a display unit having an organic light-emitting element as described in claim 16; a housing on which the display unit is provided; and a communication unit provided in the housing for communicating with the outside.

24. A lighting device characterized by comprising a light source having an organic light-emitting element as described in claim 16, and a light-diffusing section or optical filter that transmits light emitted by the light source.

25. A mobile body characterized by comprising a lamp having an organic light-emitting element as described in claim 16, and a body on which the lamp is provided.

26. It comprises a photoreceptor and an exposure light source for exposing the photoreceptor, The image forming apparatus is characterized in that the exposure light source has the organic light-emitting element described in claim 16.

Images