Organic compound and organic light-emitting device

Abstract

To provide an organic compound having excellent element life characteristics when used in an organic light-emitting element.SOLUTION: The present invention provides an organic compound represented by general formula [1]. In the formula [1], each of R1 to R8 is selected from the group consisting of a hydrogen atom, an alkyl group, and the like. A is a structure represented by the A in the figure and is bonded at a position represented by *. In the A, B is selected from structures represented by [B-1] and the like and is bonded at a position represented by *. In the [B-1] and the like, each of R9 to R17 is independently selected from a hydrogen atom, an alkyl group, and the like. X represents an oxygen atom or a sulfur atom.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an organic compound and an organic light-emitting device using the same. [Background technology]

[0002] An organic light-emitting device (hereinafter sometimes referred to as an "organic electroluminescence device" or "organic EL device") is an electronic device having a pair of electrodes and an organic compound layer disposed between these electrodes. By injecting electrons and holes from this 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 light-emitting device emits light. Recent advances in organic light-emitting devices have been remarkable, including low driving voltage, diverse emission wavelengths, fast response, and the ability to reduce the thickness and weight of light-emitting devices. Incidentally, there has been active research to date into compounds suitable for organic light-emitting devices. This is because the creation of compounds with excellent device life characteristics is important in providing high-performance organic light-emitting devices. As an example of compounds that have been created so far, in which a fused polycyclic group is substituted at the end of the phenylene group of diphenyldiazatriphenylene, the following compound 1-A is described in Patent Document 1.

[0003] [ka] [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2014 / 0034925 Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors have investigated compound 1-A and found that it has a small S1 (singlet energy) and room for improvement in terms of thermal properties. Therefore, when compound 1-A is used in an organic light-emitting device, the device has a short life span and an organic light-emitting device with excellent durability cannot be obtained. An object of the present invention is to provide an organic compound that, when used in an organic light-emitting device, has excellent element life characteristics. Another object of the present invention is to provide an organic light-emitting device that has excellent element life characteristics. [Means for solving the problem]

[0006] The organic compound of the present invention is characterized by being represented by the following general formula [1].

[0007] [ka] In formula [1], R1 to R8 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted heterocyclic group, and a cyano group. A has the structure shown below as A, and is bonded at the position indicated by *.

[0008] [ka] In the above A, B is the following [B- 7 ] to [B-15] and is bonded at the position indicated by *.

[0009] [ka] The above [B- 7 ] to [B-15], R9 to R 17are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted heterocyclic group, and a cyano group. 。 [Effects of the Invention]

[0010] The organic compound according to the present invention has large S1 and T1, and is excellent in film property and sublimation property, making it suitable for organic light-emitting devices. Therefore, by using the organic compound according to the present invention as a constituent material of an organic light-emitting device, an organic light-emitting device having good light-emitting properties and durability can be obtained. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating the characteristics of the compound of the present invention. [Figure 2] 1A is a schematic cross-sectional view showing an example of a pixel of a display device according to one embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view showing an example of a display device using an organic light-emitting element according to one embodiment of the present invention. [Figure 3] 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Figure 4] 1A is a schematic diagram illustrating an example of an imaging device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram illustrating an example of an electronic device according to an embodiment of the present invention. [Figure 5] 1A is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram illustrating an example of a foldable display device. [Figure 6] 1A is a schematic diagram showing an example of an illumination device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram showing an example of a moving body having a vehicle lamp according to an embodiment of the present invention. [Figure 7](a) A schematic diagram showing an example of a wearable device according to an embodiment of the present invention. (b) A schematic diagram showing another example of a wearable device according to an embodiment of the present invention. [Figure 8] (a) A schematic diagram representing an example of an image forming apparatus according to an embodiment of the present invention. (b) A schematic diagram representing an example of an exposure light source of an image forming apparatus according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0012] ≪Organic Compound≫ The organic compound according to this embodiment is represented by the following general formula [1].

[0013]

Chemical Formula

[0014] <R1 to R8> In formula [1], R1 to R8 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted heterocyclic group, and a cyano group.

[0015] Examples of the halogen atom include, but are not limited to, fluorine, chlorine, bromine, iodine, etc.

[0016] Examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a tertiary butyl group, a secondary butyl group, an octyl group, a cyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, etc. The number of carbon atoms of the alkyl group is preferably 1 or more and 10 or less.

[0017] Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, 2-ethyl-octyloxy, and benzyloxy groups. The number of carbon atoms in the alkoxy group is preferably 1 to 10.

[0018] Examples of the amino group include, but are not limited to, an N-methylamino group, an N-ethylamino group, an N,N-dimethylamino group, an N,N-diethylamino group, an N-methyl-N-ethylamino group, an N-benzylamino group, an N-methyl-N-benzylamino group, an N,N-dibenzylamino group, an anilino group, an N,N-diphenylamino group, an N,N-dinaphthylamino group, an N,N-difluorenylamino group, an N-phenyl-N-tolylamino group, an N,N-ditolylamino group, an N-methyl-N-phenylamino group, an N,N-dianisolylamino group, an N-mesityl-N-phenylamino group, an N,N-dimesitylamino group, an N-phenyl-N-(4-tert-butylphenyl)amino group, an N-phenyl-N-(4-trifluoromethylphenyl)amino group, and an N-piperidyl group.

[0019] Examples of the aryloxy group and heteroaryloxy group include, but are not limited to, a phenoxy group and a thienyloxy group.

[0020] Examples of the silyl group include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0021] Examples of aromatic hydrocarbon groups include, but are not limited to, phenyl, naphthyl, indenyl, biphenyl, terphenyl, fluorenyl, phenanthryl, fluoranthenyl, and triphenylenyl groups.

[0022] Examples of heterocyclic groups include, but are not limited to, pyridyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazolyl, acridinyl, phenanthrolyl, dibenzofuranyl, and dibenzothiophenyl groups.

[0023] Examples of substituents that the alkyl group, alkoxy group, amino group, aryloxy group, heteroaryloxy group, silyl group, aromatic hydrocarbon group, and heterocyclic group may further have include, but are not limited to, a deuterium atom; halogen atoms such as fluorine, chlorine, bromine, and iodine; alkyl groups such as a methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, and tertiary butyl group; alkoxy groups such as a methoxy group, ethoxy group, and propoxy group; amino groups such as a dimethylamino group, diethylamino group, dibenzylamino group, diphenylamino group, and ditolylamino group; aryloxy groups such as a phenoxy group; aromatic hydrocarbon groups such as a phenyl group and a biphenyl group; heterocyclic groups such as a pyridyl group and a pyrrolyl group; and a cyano group.

[0024] In formula [1], A is a structure represented by A below, and is bonded at the position indicated by *. [ka]

[0025] [B] In A, B is selected from the structures shown in [B-1] to [B-15] below and is bonded at the position indicated by *. Two Bs may be the same or different, but are preferably the same. [ka]

[0026] {R9~R 17 } In [B-1] to [B-15], R9 to R 17 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted heterocyclic group, and a cyano group.

[0027] Specific examples of the halogen atom, alkyl group, alkoxy group, amino group, aryloxy group, heteroaryloxy group, silyl group, aromatic hydrocarbon group, and heterocyclic group include, but are not limited to, those described for R1 to R8. The alkyl group preferably has 1 to 10 carbon atoms. The alkoxy group preferably has 1 to 10 carbon atoms. Specific examples of substituents that may be further substituted by the alkyl group, alkoxy group, amino group, aryloxy group, heteroaryloxy group, silyl group, aromatic hydrocarbon group, and heterocyclic group include, but are not limited to, those described for R1 to R8.

[0028] {X} X represents an oxygen atom or a sulfur atom.

[0029] B is preferably selected from the structures shown in [C-1] to [C-3] below. [ka]

[0030] B is preferably selected from the structures shown in [D-1] to [D-6] below. [ka]

[0031] <Synthesis method> Next, a method for synthesizing the organic compound according to this embodiment will be described. The organic compound according to this embodiment can be synthesized, for example, according to the reaction scheme shown below.

[0032] [ka]

[0033] Here, various compounds can be obtained by appropriately changing the compounds shown in (b), (f), etc. above. The method for synthesizing the organic compound of this embodiment is not limited to the above synthesis scheme, and various synthesis schemes and reagents can be used. The synthesis method will be described in detail in the Examples.

[0034] <Specific examples of organic compounds> Specific examples of the organic compound according to this embodiment are shown below, but of course, the present invention is not limited to these. (A1 to A31 are examples) .

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] [ka]

[0039] Exemplary compounds belonging to group A are compounds in which B has a structure shown in [B-1] to [B-6] and the fused rings B at both ends contain a dibenzofuran ring, a dibenzothiophene ring, or a carbazole ring. These compounds contain an oxygen atom, a sulfur atom, or a nitrogen atom in the fused ring B, and therefore can enhance charge transport properties due to the abundant lone electron pairs possessed by these atoms, making them particularly easy to adjust the carrier balance.

[0040] The exemplary compounds belonging to group B are those in which B has the structure shown in [B-7] to [B-11], and the fused rings B at both ends are SP 2 These compounds are compounds consisting of carbon atoms. 2 Because it is made up of hybrid orbitals, it is a compound with particularly excellent stability.

[0041] The exemplary compounds belonging to group C are compounds in which B has the structure shown in [B-12] to [B-15] and the fused rings B at both ends contain fluorene rings. These compounds have a methyl group at the 9-position of the fluorene ring, in the direction perpendicular to the in-plane direction of the fluorene ring, which can particularly prevent the fused rings from overlapping with each other. Furthermore, R9 to R 15 By having a tertiary alkyl group such as a t-Bu group as the hydroxyl group, intermolecular interactions can be suppressed, and therefore, even if the molecular weight is large, the compound has excellent sublimation properties.

[0042] <Properties of organic compounds> Next, the properties of the organic compound according to this embodiment will be described. The organic compound according to this embodiment has the following characteristics, and therefore has high S1 (singlet energy) and T1 (triplet energy), and is a compound that has excellent film-forming properties and sublimation properties. Furthermore, by using this organic compound, it is possible to provide an organic light-emitting device that is excellent in luminous efficiency and device durability. (1) The dibenzo[f,h]quinoxaline ring has a 1,1'-biphenylene group at the 7th and 10th positions, which has three or more fused rings B at the 3'-position, resulting in high S1 and T1. (2) The molecule contains two 1,1'-biphenylene groups, and hydrogen atoms are present at positions other than the 3- and 3'-positions of the 1,1'-biphenylene groups. Since the molecule does not contain any substituents that would increase the bond distance, the compound is highly stable.

[0043] (1) The dibenzo[f,h]quinoxaline ring has a 1,1'-biphenylene group at the 7th and 10th positions, which has three or more fused rings B at the 3'-position, resulting in high S1 and T1.

[0044] In inventing the organic compound of this embodiment, the inventors focused on the structure of the phenylene chain. Specifically, the organic compound of this embodiment has a structure in which two fused rings B each having three or more rings are linked to a dibenzo[f,h]quinoxaline ring at the center via a 1,1'-biphenylene group. Because the dibenzo[f,h]quinoxaline ring and two fused rings B each having three or more rings are linked to the 3- and 3'-positions of the 1,1'-biphenylene group, which is the linking group, the structure results in high S1 (singlet energy) and T1 (triplet energy).

[0045] Here, the results of comparing S1 (singlet energy) and T1 (triplet energy) between Example Compound A4, which is an organic compound of this embodiment, and Comparative Compound 1-C are shown in Table 1. S1 (singlet energy) and T1 (triplet energy) were determined by molecular orbital calculation.

[0046] [Table 1]

[0047] As shown in Table 1, the exemplary compound A4 has an S1 of 3.58 eV and a T1 of 2.73 eV. On the other hand, the comparative compound 1-C has an S1 of 3.28 eV and a T1 of 2.63 eV. From the above, it can be seen that the exemplary compound A4 exhibits higher values ​​for both S1 and T1.

[0048] This is thought to be because the linking group has a 1,1'-biphenylene structure and is bonded to the 7th and 10th positions of the dibenzo[f,h]quinoxaline ring.

[0049] In other words, when two 1,1'-biphenylene groups are bonded to the 6th and 11th positions of a dibenzo[f,h]quinoxaline ring (the 6,11-position substituted compound shown in Figure 1(b)), the two benzene rings contained in the dibenzo[f,h]quinoxaline ring, the benzene ring contained in the biphenylene group bonded to the 6th position, and the benzene ring contained in the biphenylene group bonded to the 11th position are aligned in a straight line. In other words, the structure is one in which four benzene rings are aligned in a straight line. This extends the conjugated system, lowering both S1 and T1. On the other hand, when two 1,1'-biphenylene groups are bonded to the 7th and 10th positions of the dibenzo[f,h]quinoxaline ring (the 7,10-position substituted compound shown in Figure 1(a)), one of the pyrazine and benzene rings in the dibenzo[f,h]quinoxaline ring is aligned with either the benzene ring in the biphenylene group bonded to the 7th position or the benzene ring in the biphenylene group bonded to the 10th position. In other words, a structure is formed in which three aromatic or heterocyclic rings are aligned in a straight line. This results in a shorter conjugated system than when two 1,1'-biphenylene groups are bonded to the 6th and 11th positions of the dibenzo[f,h]quinoxaline ring, thereby increasing S1 and T1.

[0050] Here, the effects of high S1 energy and T1 energy will be explained. Phosphorescent light-emitting devices are organic light-emitting devices that use T1 energy for light emission. A host material for the emitting layer of an organic light-emitting device preferably has a higher T1 energy than a phosphorescent material that emits phosphorescence. Furthermore, when used as a carrier-blocking layer around the emitting layer, it is preferable that not only T1 but also S1 be high. Generally, as T1 energy increases, S1 energy also increases. On the other hand, a high S1 energy means a large band gap. Therefore, when used as a host material for the emitting layer or a carrier-blocking layer around the emitting layer, it is highly stable against excessive exciton concentration and unnecessary charge accumulation, which is advantageous for device durability and is therefore preferable. Therefore, organic compounds with sufficiently high S1 energy and T1 energy are preferred.

[0051] The organic compound of this embodiment has 1,1'-biphenylene groups as linking groups at the 7- and 10-positions of the dibenzo[f,h]quinoxaline ring and a fused ring B at the 3'-position, which results in sufficiently high S1 energy and T1 energy. Therefore, when this organic compound is used as a host material for the light-emitting layer or a carrier-blocking layer of an organic light-emitting device, it is possible to provide a device with high efficiency and long life.

[0052] The molecular orbital calculation method used was the density functional theory (DFT), which is currently widely used. The functional was B3LYP, and the basis set was 6-31G. * It is also a smooth-flowing waveguide called Gaussian09(Gaussian09, RevisionC.01,MJFrisch,GWTrucks,HBSchlegel,GEScuse ria, MARobb,JRCheeseman,G.Scalmani,V.Barone,B.Mennucci,GAPetersson,H.Nakatsuji,M.Caricato,X.Li,HPHra tchian, AFIzmaylov, J. Bloino, G. Zheng, JLSonnenberg, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishi da,T.Nakajima,Y.Honda,O.Kitao,H.Nakai,T.Vreven,JAMontgomery,Jr.,JEPeralta,F.Ogliaro,M.Bearpark,JJHe yd, E. Brothers, KNKudin, VNS Taroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, JCBurant ,SSIyengar,J.Tomasi,M.Cossi,N.Rega,JMMillam,M.Klene,JEKnox,JBCross,V.Bakken,C.Adamo,J.Jaramillo,R.G omperts,REStratmann,O.Yazyev,AJAustin,R.Cammi,C.Pomelli,JWOchterski,RLMartin,K.Morokuma,VGZakrzews ki,GAVoth,P.Salvador,JJDannenberg,S.Dapprich,ADDaniels,O.Farkas,JBForesman,JVOrtiz,JCioslowski,and DJFox,Gaussian,Inc.,Wallingford CT,2010.)

[0053] (2) The molecule contains two 1,1'-biphenylene groups, and hydrogen atoms are present at positions other than the 3- and 3'-positions of the 1,1'-biphenylene groups. Since the molecule does not contain any substituents that would increase the bond distance, the compound is highly stable.

[0054] In inventing the organic compound of this embodiment, the inventors focused on the degree of rotational freedom of the bond possessed by the organic compound. Specifically, the organic compound of this embodiment has a structure in which three or more fused rings, including a dibenzo[f,h]quinoxaline ring, are bonded to the 3- and 3'-positions of two 1,1'-biphenylene groups. Furthermore, the organic compound of this embodiment has a structure in which hydrogen atoms are present at substitution positions other than the 3- and 3'-positions of the 1,1'-biphenylene groups, and the compound does not have any substituents that would increase the bond distance. Therefore, the organic compound has a high degree of rotational freedom.

[0055] Here, the results of a comparison of the thermal properties of Example Compound A4, which is an organic compound of this embodiment, and Comparative Compound 1-A are shown in Table 2. Note that Comparative Compound 1-A is Compound 1-A described in Patent Document 1.

[0056] [Table 2]

[0057] As shown in Table 2, the biphenylene group connecting the fused rings B at both ends of the molecular structure increases the molecular weight and also increases the degree of rotational freedom of the bond.

[0058] Comparative Compound 1-A has carbazole rings as fused rings at both ends, and a phenylene group is used as a linking group between the central dibenzoquinoxaline ring. On the other hand, Example Compound A4 has dibenzofuran rings as fused rings B at both ends, and a biphenylene group is used as a linking group between the central dibenzoquinoxaline ring, so it can be seen that the degree of rotational freedom within the molecule is greater than that of Comparative Compound 1-A.

[0059] By introducing a biphenylene group as a linking group, the molecular weight increases and the degree of freedom of rotation of the bond increases, which has the following effects.

[0060] First, increasing the molecular weight can suppress molecular packing, which is the overlapping of molecules, making the material less likely to crystallize and more amorphous. High amorphousness, or in other words, good filmability, is desirable for use in organic light-emitting devices. This is because high amorphousness reduces the generation of grain boundaries, trap levels, and quenchers associated with microcrystallization, even during device operation, allowing for the maintenance of good carrier transport and highly efficient light-emitting properties. As a result, organic light-emitting devices with excellent durability and efficiency can be provided.

[0061] The glass transition temperatures and crystallization temperatures of Example Compound A4 and Comparative Compound 1-A were evaluated by differential scanning calorimetry (DSC), and the results are shown in Table 2. The higher the glass transition temperature, or the higher or no crystallization temperature is observed, the higher the amorphousness and the better the thermal stability. For the DSC measurement, approximately 2 mg of sample was sealed in an aluminum pan and rapidly cooled from a temperature above the melting point to make the sample amorphous. The glass transition temperature and crystallization temperature were then measured by increasing the temperature at a rate of 10°C / min. The measurement device used was a DSC 204 F1 manufactured by NETZSCH.

[0062] Comparative Compound 1-A had a glass transition temperature of 155°C, and a crystallization temperature was observed at 304°C during heating. On the other hand, Exemplified Compound A4 had a glass transition temperature of 133°C, and no crystallization temperature was observed during heating. In other words, the thin film formed by thermal evaporation in a vacuum is free from the risk of crystallization, and is a compound with high amorphousness and excellent thermal stability. In other words, a stable amorphous film can be maintained even during device operation, making it possible to provide an organic light-emitting device with a long life.

[0063] Second, increasing the degree of rotational freedom of the bond lowers the sublimation temperature and improves sublimability. When the degree of rotational freedom of a compound is low, organic compounds tend to aggregate, resulting in reduced sublimability. Furthermore, compared to Comparative Compound 1-A, Exemplified Compound A4 simply has an increased molecular weight, which tends to make it more susceptible to poor sublimability. However, by using a 1,1'-biphenylene group as the linking group for the three fused rings present in the molecule and bonding the fused rings to the 3- and 3'-positions, the degree of rotational freedom of the bond is increased, making it easier to avoid intermolecular stacking. Therefore, it is possible to form a good film without any problems with sublimability.

[0064] The evaluation of the light-emitting properties and thermal stability of the organic compound of this embodiment, which are listed as features (1) and (2), will be described in more detail in the examples described later.

[0065] Furthermore, the organic compound of this embodiment can be particularly suitably used in an organic light-emitting device when it further has the following characteristics. (3) Both terminal fused rings B are sp 3 It has no carbon. (4) The fused rings B at both ends and the linking group are bonded at substitution positions that do not interfere with each other due to steric hindrance. These features will be explained below.

[0066] (3) Both terminal fused rings B are SP 3 It has no carbon.

[0067] In the organic compound of this embodiment, the central dibenzoquinoxaline ring and the biphenylene group serving as the linking group are SP 3 In addition to having no carbon, the fused rings B at both ends are SP 3 It is preferable to have no carbon because SP 2 This is because the carbon-carbon bond has a large bond energy, and therefore bond cleavage is unlikely to occur during operation of the organic light-emitting device. Therefore, from the viewpoint of improving the durability of the device, the fused rings B at both ends are SP 3 It is preferable that the fused ring B does not have carbon. Specifically, it is preferable that B has a structure shown in [B-1] to [B-11], and the fused ring B is a phenanthrene ring, a dibenzofuran ring, a dibenzothiophene ring, or a carbazole ring.

[0068] (4) The fused rings B at both ends and the linking group are bonded at substitution positions that do not interfere with each other due to steric hindrance.

[0069] In the organic compound of this embodiment, the fused rings B at both ends and the linking group are preferably bonded at substitution positions that do not interfere with each other due to steric hindrance. This is because, when the fused rings B and the linking group do not interfere with each other due to steric hindrance, the bond distance between the fused rings B and the linking group is unlikely to become large, resulting in a bond that is difficult to cleave.

[0070] Table 3 shows the results of a comparison of the bond distances between Exemplary Compound B2 and Exemplary Compound B3.

[0071] [Table 3]

[0072] In Table 3, the bond between the terminal fused ring B and the linking group is designated as a, and the dihedral angle is shown. The dihedral angle for example compound B2 is 36.5°, while the dihedral angle for example compound B3 is 57.0°. This means that example compound B2 has higher planarity due to the steric hindrance of the hydrogen atoms at the peri-position of the phenanthrene ring. Higher planarity leads to higher carrier mobility. A structure with high planarity, such as example compound B2, improves heat resistance and makes bonds less likely to break.

[0073] Therefore, it is preferable that the fused ring B and the linking group are bonded at a substitution position that does not interfere with each other due to steric hindrance.

[0074] The bond distances were visualized using molecular orbital calculations.

[0075] <Organic light-emitting element> The organic light-emitting element of this embodiment has at least a pair of electrodes, an anode and a cathode, and an organic compound layer disposed between these electrodes. 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. When the organic compound layer is a laminate consisting of multiple layers, the organic compound layer may have, in addition to the light-emitting layer, 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. Furthermore, the light-emitting layer may be a single layer or a laminate consisting of multiple layers.

[0076] In the organic light-emitting device of this embodiment, the organic compound according to this embodiment is contained in at least one of the organic compound layers. Specifically, the organic compound according to this embodiment is contained in any of the above-mentioned light-emitting layer, hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole / exciton blocking layer, electron transport layer, electron injection layer, etc. The organic compound according to this embodiment is preferably contained in the light-emitting layer.

[0077] In the organic light-emitting device of this embodiment, when the organic compound according to this embodiment is contained in the light-emitting layer, the light-emitting layer may be a layer consisting solely of the organic compound according to this embodiment, or may be a layer consisting of the organic compound according to this embodiment and other compounds. Here, when the light-emitting layer is a layer consisting of the organic compound according to this embodiment and other compounds, the organic compound according to this embodiment may be used as a host or a guest of the light-emitting layer. It may also be used as an assist material that can be contained in the light-emitting layer. Here, the host is the compound with the largest mass ratio among the compounds constituting the light-emitting layer. Furthermore, the guest is a compound that is smaller in mass ratio than the host among the compounds constituting the light-emitting layer and is responsible for the main emission of light. Furthermore, the assist material is a compound that is smaller in mass ratio than the host among the compounds constituting the light-emitting layer and assists the emission of the guest. The assist material is also called a second host.

[0078] The present inventors have conducted various studies and found that when the organic compound according to this embodiment is used as a host or assist for the light-emitting layer, particularly as a host for the light-emitting layer, a device exhibiting high efficiency and high luminance light output and extremely high durability can be obtained. This light-emitting layer may be a single layer or multiple layers. For example, the light-emitting color of this embodiment may be green, and a light-emitting material having another light-emitting color may be added to achieve color mixing. "Multiple layers" refers to a state in which the light-emitting layer and another light-emitting layer are stacked. In this case, the light-emitting color of the organic light-emitting device is not limited to green. More specifically, it may be white or a neutral color. In the case of white, the other light-emitting layer emits a color other than green, i.e., blue or red. Furthermore, the film is formed by vapor deposition or coating. Details of this will be explained in detail in the examples below.

[0079] The organic compound according to this embodiment can be used as a constituent material of an organic compound layer other than the light-emitting layer that constitutes the organic light-emitting device of this embodiment. Specifically, it may be used as a constituent material of an electron transport layer, an electron injection layer, a hole transport layer, a hole injection layer, a hole blocking layer, etc. In this case, the emission color of the organic light-emitting device is not limited to green. More specifically, it may be white or a neutral color.

[0080] The compound of this embodiment is preferably used in the light-emitting layer of the organic light-emitting device under the following conditions. (1) The compound of this embodiment is used in an amount of 30% by mass or more and 99% by mass or less in the light-emitting layer. (2) The light-emitting material to be mixed with the compound of this embodiment in the light-emitting layer is a phosphorescent material, and the phosphorescent material is an organometallic complex having at least three or more fused rings in the ligand. The above conditions will be explained below.

[0081] (1) The compound of this embodiment is used in an amount of 30% by mass or more and 99% by mass or less in the light-emitting layer.

[0082] When the organic compound of this embodiment is used in the light-emitting layer, it is preferably used in a content of 30% by mass or more and 99% by mass or less based on the entire light-emitting layer. The organic compound of this embodiment is highly amorphous, making it suitable as a host material for the light-emitting layer. When used as a host material, the content is preferably 50% by mass or more and 99% by mass or less, and more preferably 70% by mass or more and 99% by mass or less. Even when used at 99% by mass, the compound is difficult to crystallize, so it is a compound that exhibits excellent properties. Furthermore, from the viewpoint of improving the film properties of the light-emitting layer, the compound may be used as an assist material. When used as an assist material, it can be used in a content of 30% by mass or more and less than 50% by mass. This is due to the structural characteristics of the organic compound of this embodiment. The compound is difficult to aggregate, and even when the organic light-emitting device is driven, crystal grain boundaries associated with molecular aggregation are unlikely to occur, making it possible to provide a light-emitting device with excellent properties.

[0083] (2) The light-emitting material to be mixed with the compound of this embodiment in the light-emitting layer is a phosphorescent material, and the phosphorescent material is an organometallic complex having at least three or more fused rings in the ligand.

[0084] The organic compound of this embodiment is a compound having three or more fused rings B at both ends. Therefore, the phosphorescent material used in the light-emitting layer together with the organic compound of this embodiment preferably has a structure in which the π-conjugation of the ligand is extended. More specifically, an organometallic complex having three or more fused rings in the ligand structure is preferred. This is because, like the organic compound of this embodiment as a host material, the organometallic complex as a guest material has a highly planar structure, allowing highly planar portions to interact with each other and approach each other. More specifically, the planar portions of the host material and the ligands of the organometallic complex are more likely to approach each other. This is expected to shorten the intermolecular distance between the host material and the organometallic complex.

[0085] It is known that triplet energy used in phosphorescent light-emitting devices undergoes energy transfer via the Dexter mechanism. The Dexter mechanism involves energy transfer through molecular contact. In other words, shortening the intermolecular distance between the host material and the guest material results in efficient energy transfer from the host material to the guest material. By using a highly planar organometallic complex having three or more fused rings in its ligand structure, the intermolecular distance with the host material, which is the organic compound of this embodiment, is shortened, facilitating more efficient energy transfer from the host to the organometallic complex. As a result, a highly efficient organic light-emitting device can be provided.

[0086] Here, the highly planar fused ring structure of three or more rings possessed by the ligand refers to, for example, a triphenylene ring, a phenanthrene ring, a fluorene ring, a benzofluorene ring, a dibenzofuran ring, a dibenzothiophene ring, a benzoisoquinoline ring, a naphthoisoquinoline ring, etc. In other words, by using an organometallic complex having at least one of these structures as a ligand as a light-emitting material, the organic compound of this embodiment can provide a light-emitting device with higher efficiency.

[0087] <Examples of organometallic complexes> Specific examples of organometallic complexes are shown below, but are of course not limited to these. Specific examples of organometallic complexes include organometallic complexes having partial structures represented by the following general formulas [Ir-1] to [Ir-16].

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[0090] In the above general formulas [Ir-1] to [Ir-16], Ar1 and Ar2 are each independently selected from a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted heterocyclic group, and a cyano group. p is an integer of 0 to 4, and when p is 2 or greater, multiple Ar1s may be the same or different. q is an integer of 0 to 4, and when q is 2 or greater, multiple Ar2s may be the same or different.

[0091] X is selected from an oxygen atom, a sulfur atom, a substituted or unsubstituted carbon atom, and a substituted or unsubstituted nitrogen atom. Examples of the substituent on the carbon atom or nitrogen atom include a substituted or unsubstituted alkyl group and a substituted or unsubstituted aromatic hydrocarbon group.

[0092] m is an integer of 1 or more and 3 or less, and when m is 2 or more, the plurality of ligands may be the same or different.

[0093] The fused ring bonded to the pyridine ring in the general formulae [Ir-1] to [Ir-8] and the fused ring bonded to the benzene ring in the general formulae [Ir-9] to [Ir-16] may have a substituent such as a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or a cyano group.

[0094] Specific examples of the halogen atom, alkyl group, alkoxy group, silyl group, aromatic hydrocarbon group, and heterocyclic group in the general formulae [Ir-1] to [Ir-16] include, but are not limited to, those described for R1 to R8. The alkyl group preferably has 1 to 10 carbon atoms. Specific examples of the substituent that the alkyl group, silyl group, aromatic hydrocarbon group, and heterocyclic group may further have include, but are not limited to, those described for R1 to R8.

[0095] Among the metal complexes having the partial structures represented by the above general formulae [Ir-1] to [Ir-16], metal complexes having three or more fused rings in the ligand are more preferred. Specifically, they are metal complexes having the partial structures represented by the above general formulae [Ir-3] to [Ir-8] and [Ir-11] to [Ir-16]. Specific examples thereof are shown below, but the present invention is not limited to these.

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[0112] The exemplary compounds belonging to the AA group to the BB group are metal complexes having a partial structure represented by the general formula [Ir-3], and are compounds having at least a phenanthrene ring in the ligand. 2 Because it is made up of hybrid orbitals, it is a compound with particularly excellent stability.

[0113] The exemplary compounds belonging to the CC group are metal complexes having a partial structure represented by the general formula [Ir-4], and are compounds having at least a triphenylene ring in the ligand. These compounds have a fused ring in the SP 2 Because it is made up of hybrid orbitals, it is a compound with particularly excellent stability.

[0114] The exemplary compounds belonging to the DD group are metal complexes having partial structures represented by general formulas [Ir-5] to [Ir-8], and are compounds having at least a dibenzofuran ring, a dibenzothiophene ring, a benzonaphthofuran ring, or a benzonaphthothiophene ring in the ligand. These compounds contain oxygen atoms and sulfur atoms in the fused ring, and the abundant unshared electron pairs possessed by these atoms can enhance charge transport properties, making them particularly easy to adjust the carrier balance.

[0115] The exemplary compounds belonging to the EE group to the GG group are metal complexes having partial structures represented by the general formulas [Ir-6] to [Ir-8], and are compounds having at least a benzofluorene ring in the ligand. These compounds have a substituent at the 9-position of the fluorene ring, in the direction perpendicular to the in-plane direction of the fluorene ring, which can particularly prevent the fused rings from overlapping with each other. Therefore, these compounds have particularly excellent sublimation properties.

[0116] The exemplary compounds belonging to the HH group are metal complexes having partial structures represented by the general formulas [Ir-11] to [Ir-13], and are compounds having at least a benzoisoquinoline ring in the ligand. These compounds contain N atoms in the fused ring, and the lone electron pairs and high electronegativity of these atoms can enhance charge transport properties, making them particularly easy to adjust the carrier balance.

[0117] The exemplary compounds belonging to Group II are metal complexes having a partial structure represented by the general formula [Ir-14], and are compounds having at least a naphthoisoquinoline ring in the ligand. These compounds contain N atoms in the fused ring, and the unshared electron pairs and high electronegativity of these atoms can enhance charge transport properties, making them particularly easy to adjust the carrier balance.

[0118] <Compounds other than the organic compound according to this embodiment> In addition to the organic compound according to this embodiment, conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host compounds, light-emitting compounds, electron-injecting or electron-transporting compounds, etc. may also be used together as needed. Examples of these compounds are listed below.

[0119] As the hole injection and transport material, a material with high hole mobility is preferred so that holes can be easily injected from the anode and the injected holes can be transported to the light-emitting layer. Furthermore, a material with a high glass transition temperature is preferred to suppress deterioration of film quality, such as crystallization, in organic light-emitting devices. Examples of low-molecular-weight and high-molecular-weight materials with hole injection and transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. Furthermore, the above-mentioned hole injection and transport materials are also suitable for use in electron blocking layers. Specific examples of compounds that can be used as hole injection and transport materials are listed below, but the present invention is not limited to these.

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[0121] Examples of light-emitting materials that are primarily involved in light-emitting function include 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-quinolinolato)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. Specific examples of compounds that can be used as light-emitting materials are listed below, but the present invention is not limited to these.

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[0124] The light-emitting layer host or light-emitting assist material contained in the light-emitting layer may contain a compound other than the organic compound of this embodiment as a third component. Examples of the third component include aromatic hydrocarbon compounds or derivatives thereof, carbazole derivatives, azine derivatives, xanthone derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, and organic beryllium complexes.

[0125] In particular, materials having a carbazole skeleton, materials having an azine ring such as a diazine ring or a triazine ring in the skeleton, and materials having a xanthone skeleton are preferred as assist materials. This is because these materials have high electron donating and electron withdrawing properties, making it easy to adjust the HOMO and LUMO levels. The organic compound of this embodiment has a structure in which three or more fused rings B are bonded to both ends of a biphenylene chain, resulting in a somewhat wide band gap. Therefore, materials having the above skeletons that can adjust the HOMO and LUMO levels are particularly preferred as assist materials. When these assist materials are combined with the organic compound of this embodiment, a good carrier balance can be achieved.

[0126] Specific examples of compounds used as the light-emitting layer host or light-emitting assist material in the light-emitting layer are shown below, but of course, the present invention is not limited to these. Among the specific examples below, materials having a carbazole skeleton that are preferred as assist materials are EM32 to EM38. Materials having an azine ring in the skeleton that are preferred as assist materials are EM35, EM36, EM37, EM38, EM39, and EM40. Materials having a xanthone skeleton that are preferred as assist materials are EM28 and EM30.

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[0128] The electron transport material can be arbitrarily selected from those capable of transporting electrons injected from the cathode to the light-emitting layer, and is selected taking into consideration the balance with the hole mobility of the hole transport material. Examples of materials having electron transport properties include oxadiazole derivatives, oxazole 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 transport materials are also suitable for use in hole-blocking layers. Specific examples of compounds used as electron transport materials are shown below, but of course, the present invention is not limited to these.

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[0130] <Configuration of organic light-emitting element> The organic light-emitting element is provided by forming an insulating layer, a first electrode, an organic compound layer, and a second electrode on a substrate. A protective layer, a color filter, a microlens, etc. may be provided on the second electrode. When a color filter is provided, a planarizing layer may be provided between the color filter and the protective layer. The planarizing layer may be made of an acrylic resin, etc. The same applies when a planarizing layer is provided between the color filter and the microlens.

[0131] [substrate] Examples of the substrate include quartz, glass, a silicon wafer, a resin, and a metal. Furthermore, the substrate may be provided with a switching element such as a transistor and wiring, and an insulating layer thereon. Any material can be used for the insulating layer, as long as it allows for the formation of a contact hole so that wiring can be formed between the first electrode and the insulating layer, and ensures insulation from wiring that is not connected. For example, resins such as polyimide, silicon oxide, silicon nitride, etc. can be used.

[0132] [electrode] A pair of electrodes can be used. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0133] The anode material should have as high a work function as possible. Examples include simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, mixtures containing these metals, alloys of these metals, and metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0134] These electrode materials may be used alone or in combination of two or more. The anode may be composed of one layer or multiple layers.

[0135] When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates thereof can be used. The above materials can also function as a reflective film without functioning as an electrode. When used as a transparent electrode, transparent conductive oxide layers such as indium tin oxide (ITO) and indium zinc oxide can be used, but are not limited to these. Photolithography techniques can be used to form the electrode.

[0136] On the other hand, materials with a low work function are preferred for the cathode. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, and metals such as aluminum, titanium, manganese, silver, lead, and chromium, as well as mixtures containing these metals. Alternatively, alloys combining these metals can 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 can be used alone or in combination. The cathode can have either 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 critical as long as silver aggregation can be reduced. For example, the silver:other metal ratio can be 1:1, 3:1, or the like.

[0137] 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 DC and AC sputtering methods are more preferred because they provide good film coverage and make it easier to reduce resistance.

[0138] [Organic compound layer] The organic compound layer may be formed as a single layer or as multiple layers. When multiple layers are included, they may be called 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 functions. The organic compound layer is mainly composed of organic compounds but may also contain inorganic atoms or inorganic compounds. For example, the organic compound layer may contain copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, or the like. The organic compound layer may be disposed between the first electrode and the second electrode, or may be disposed in contact with the first electrode and the second electrode.

[0139] The organic compound layers (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 device according to one embodiment of the present invention are formed by the method shown below.

[0140] The organic compound layer constituting the organic light-emitting device according to one embodiment of the present invention can be formed by dry processes such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Alternatively to the dry process, a wet process can be used in which the compound is dissolved in an appropriate solvent and a layer is formed by a known coating method (for example, spin coating, dipping, casting, LB method, inkjet method, etc.).

[0141] Here, when a layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When a film is formed by a coating method, the film can be formed by combining with an appropriate binder resin.

[0142] Examples of the binder resin include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0143] These binder resins may be used singly or in combination as homopolymers or copolymers, and may further contain known additives such as plasticizers, antioxidants, and ultraviolet absorbers, if necessary.

[0144] [Protective layer] A protective layer may be provided on the second electrode. For example, by adhering glass with a moisture absorbent on the second electrode, the infiltration of water and other contaminants 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 infiltration of water and other contaminants into the organic compound layer. For example, after forming the second electrode, the second electrode may be transferred to another chamber without breaking the vacuum, and a 2 μm-thick silicon nitride film may be formed by CVD to serve as a protective layer. A protective layer may be provided using atomic layer deposition (ALD) after the CVD film formation. The material of the film formed by ALD is not limited, and may be silicon nitride, silicon oxide, aluminum oxide, or the like. Silicon nitride may be further formed on the film formed by ALD by CVD. The film formed by ALD may have a thickness smaller than that of the film formed by CVD. Specifically, the thickness may be 50% or less, or even 10% or less.

[0145] [Color Filter] A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on a separate substrate and then bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer described above using photolithography technology. The color filter may be made of a polymer.

[0146] [Planarization layer] A planarization layer may be provided between the color filter and the protective layer. The planarization layer is provided for the purpose of reducing the unevenness of the underlying layer. It may also be called a material resin layer without limiting its purpose. The planarization layer may be composed of an organic compound, and may be either a low molecular weight or a high molecular weight, but a high molecular weight is preferred.

[0147] The planarizing layer may be provided above or below the color filter, and may be made of the same or different materials, such as polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0148] [Microlens] The organic light-emitting element or organic light-emitting device may have an optical component such as a microlens on its light-emitting side. The microlens may be made of acrylic resin, epoxy resin, or the like. The microlens may be intended to increase the amount of light extracted from the organic light-emitting element or organic light-emitting device or to control the direction of the extracted light. The microlens may have a hemispherical shape. When the microlens has a hemispherical shape, among the tangents to the hemisphere, there is a tangent that is parallel to the insulating layer, and the vertex of the microlens is the point of contact between this tangent and the hemisphere. The vertex of the microlens can be determined in the same way in any cross-sectional view. In other words, among the tangents to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the vertex of the microlens is the point of contact between this tangent and the semicircle.

[0149] It is also possible to define the midpoint of a microlens. In the cross section of the microlens, a line segment is imagined from the point where an arc shape ends to the point where another arc shape ends, and the midpoint of this line segment can be called the midpoint of the microlens. The cross section for determining the vertex and midpoint may be a cross section perpendicular to the insulating layer.

[0150] [Counter substrate] An opposing substrate may be provided on the planarization layer. The opposing substrate is called an opposing substrate because it is provided at a position corresponding to the aforementioned substrate. The constituent material of the opposing substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate is defined as a first substrate, the opposing substrate may be a second substrate.

[0151] [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 controls the emission of the first light-emitting element and the second light-emitting element independently. The active matrix type circuit may be voltage-programmed or current-programmed. The drive circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor that controls the emission brightness of the light-emitting element, a transistor that controls the emission timing, a capacitor that holds the gate voltage of the transistor that controls the emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0152] 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 a transistor constituting the pixel circuit may be smaller than the mobility of a transistor constituting the display control circuit. The slope of the current-voltage characteristics of the transistor constituting the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistor constituting the display control circuit. The slope of the current-voltage characteristics can be measured by the so-called Vg-Ig characteristics. The transistor constituting the pixel circuit is a transistor connected to a light-emitting element, such as a first light-emitting element.

[0153] [Pixels] An organic light emitting device having an organic light emitting element may have a plurality of pixels, each of which has sub-pixels that emit different colors, for example, RGB colors.

[0154] A pixel emits light from an area called a pixel aperture. This area is the same as the first area. The pixel aperture may be 15 μm or less, or 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 may be 10 μm or less, more specifically, it may be 8 μm, 7.4 μm, or 6.4 μm.

[0155] The pixels may be arranged in a known manner in a plan view. For example, they may be in a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixels in a plan view may be any known shape. For example, they may be rectangular, quadrilaterals such as diamonds, or hexagons. Of course, a shape that is close to a rectangle, rather than an exact shape, is included in the rectangle. The shape of the subpixels and the pixel arrangement may be used in combination.

[0156] <Applications of organic light-emitting devices> The organic light-emitting device according to this embodiment can be used as a component of a display device or a lighting device, and can also be used as an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, or a light-emitting device having a white light source and a color filter.

[0157] The display device may be an image information processing device that has an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., has an information processing unit that processes the input information, and displays the input image on a display unit. The display device may have a plurality of pixels, at least one of which may have the organic light-emitting element of this embodiment and a transistor connected to the organic light-emitting element.

[0158] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of this touch panel function may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method, and is not particularly limited. The display device may also be used in the display unit of a multifunction printer.

[0159] Next, a display device according to this embodiment will be described with reference to the drawings. Fig. 2 is a 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).

[0160] FIG. 2(a) shows an example of a pixel, which is a component of the display device according to this embodiment. The pixel includes sub-pixels 10. The sub-pixels are divided into 10R, 10G, and 10B based on their light emission. The emitted colors may be distinguished by the wavelength of light emitted from the light-emitting layer, or the light emitted from the sub-pixels may be selectively transmitted or color-converted using a color filter or the like. Each sub-pixel 10 includes a reflective electrode serving as a first electrode 2 on an interlayer insulating layer 1, an insulating layer 3 covering the edge of the first electrode 2, an organic compound layer 4 covering the first electrode 2 and the insulating layer 3, a transparent electrode serving as a second electrode 5, a protective layer 6, and a color filter 7.

[0161] A transistor and a capacitor element may be disposed below or inside the interlayer insulating layer 1. The transistor and the first electrode 2 may be electrically connected via a contact hole or the like (not shown).

[0162] The insulating layer 3 is also called a bank or a pixel separation film. It covers the edges of the first electrode 2 and is disposed to surround the first electrode 2. The portion where the insulating layer 3 is not disposed is in contact with the organic compound layer 4 and becomes a light-emitting region.

[0163] The organic compound layer 4 includes a hole injection layer 41 , a hole transport layer 42 , a first light-emitting layer 43 , a second light-emitting layer 44 , and an electron transport layer 45 .

[0164] The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0165] The protective layer 6 reduces the penetration of moisture into the organic compound layer 4. Although the protective layer 6 is illustrated as being one layer, it may be multiple layers, and each layer may be an inorganic compound layer and an organic compound layer.

[0166] The color filters 7 are divided into 7R, 7G, and 7B depending on their colors. The color filters 7 may be formed on a planarization film (not shown). A resin protective layer (not shown) may be provided on the color filters 7. The color filters 7 may be formed on a protective layer 6. Alternatively, the color filters 7 may be provided on an opposing substrate such as a glass substrate and then bonded thereto.

[0167] The display device 100 in FIG. 2(b) has an organic light-emitting element 26 and a TFT 18 as an example of a transistor. A substrate 11 made of glass, silicon, or the like is provided with an insulating layer 12 on top of it. An active element such as the TFT 18 is disposed on the insulating layer 12, and a gate electrode 13, a gate insulating film 14, and a semiconductor layer 15 of the active element are disposed on top of it. The TFT 18 also includes a drain electrode 16 and a source electrode 17. An insulating film 19 is provided on top of the TFT 18. An anode 21 constituting the organic light-emitting element 26 and the source electrode 17 are connected via a contact hole 20 provided in the insulating film 19.

[0168] The electrical connection method between the electrodes (anode 21, cathode 23) included in the organic light-emitting element 26 and the electrodes (source electrode 17, drain electrode 16) included in the TFT 18 is not limited to the embodiment shown in Fig. 2(b). In other words, it is sufficient that either the anode 21 or the cathode 23 is electrically connected to either the source electrode 17 or the drain electrode 16 of the TFT 18. TFT stands for thin film transistor.

[0169] 2(b), the organic compound layer 22 is illustrated as a single layer, but may be a multi-layer organic compound layer 22. A first protective layer 24 and a second protective layer 25 are provided on the cathode 23 to reduce deterioration of the organic light-emitting element 26.

[0170] In the display device 100 of FIG. 2(b), transistors are used as switching elements, but other switching elements may be used instead.

[0171] The transistors used in the display device 100 of Fig. 2(b) are not limited to transistors using single-crystal silicon wafers, but may also be thin-film transistors having an active layer on an insulating surface of a substrate. Examples of active layers include single-crystal silicon, amorphous silicon, microcrystalline silicon, and other non-single-crystal silicon, as well as non-single-crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin-film transistors are also called TFT elements.

[0172] The transistors included in the display device 100 of Fig. 2(b) may be formed within a substrate such as a Si substrate. Here, "formed within a substrate" means that the substrate itself, such as a Si substrate, is processed to form the transistors. In other words, having a transistor within a substrate can be seen as the substrate and the transistor being formed integrally.

[0173] The organic light-emitting element according to this embodiment has its emission brightness controlled by a TFT, which is an example of a switching element. By providing multiple organic light-emitting elements on a surface, an image can be displayed based on the emission brightness of each element. Note that the switching element according to this embodiment is not limited to a TFT, and may be a transistor formed from low-temperature polysilicon or an active matrix driver formed on a substrate such as a Si substrate. "On the substrate" can also be referred to as "inside the substrate." Whether to provide a transistor in the substrate or to use a TFT is determined by the size of the display unit. For example, for a display size of about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

[0174] 3 is a schematic diagram illustrating an example of a display device according to this embodiment. The display device 1000 may include a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The touch panel 1003 and the display panel 1005 are connected by flexible printed circuits FPCs 1002 and 1004. Transistors are printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position even if the display device is a portable device.

[0175] The display device according to this embodiment may have color filters having red, green, and blue colors, which may be arranged in a delta arrangement.

[0176] The display device according to the present embodiment may be used as a display unit of a mobile terminal. In this case, the display device may have both a display function and an operation function. Examples of the mobile terminal include a mobile phone such as a smartphone, a tablet, and a head-mounted display.

[0177] The display device according to this embodiment may be used as a display unit of an imaging device having an optical unit with a plurality of lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the imaging device or a display unit disposed within a viewfinder. The imaging device may be a digital camera or a digital video camera.

[0178] 4A 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 may include a display device according to this embodiment. In this case, the display device may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the speed at which the subject is moving, the possibility that the subject will be blocked by an obstruction, and the like.

[0179] Since the optimum timing for capturing an image is very short, it is better to display information as soon as possible. Therefore, it is preferable to use a display device using the organic light-emitting element of this embodiment. This is because the organic light-emitting element has a fast response speed. A display device using the organic light-emitting element can be used more preferably than a liquid crystal display device, which requires a high display speed.

[0180] The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses, which form an image on an imaging element housed in a housing 1104. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically. The imaging device may also be called a photoelectric conversion device. Instead of sequentially capturing images, the photoelectric conversion device can include an imaging method that detects the difference from the previous image, or a method of cutting out an image from a constantly recorded image, etc.

[0181] FIG. 4(b) is a schematic diagram illustrating 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 reaction unit. The operation unit 1202 may be a biometric recognition unit that recognizes a fingerprint to perform unlocking or the like. 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. An image captured by the camera function is displayed on the display unit 1201. Examples of the electronic device 1200 include a smartphone and a laptop computer.

[0182] FIG. 5 is a schematic diagram illustrating an example of a display device according to this embodiment. FIG. 5(a) illustrates 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 may use a light-emitting element according to this embodiment. The display device 1300 has the frame 1301 and a base 1303 that supports the display unit 1302. The base 1303 is not limited to the form shown in FIG. 5(a). The lower side of the frame 1301 may also serve as the base. 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.

[0183] FIG. 5(b) is a schematic diagram illustrating another example of a display device according to this embodiment. The display device 1310 in FIG. 5(b) is configured to be bendable, 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 may include light-emitting elements according to this embodiment. The first display unit 1311 and the second display unit 1312 may be a single, seamless display unit. The first display unit 1311 and the second display unit 1312 can be separated by 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 display a single image.

[0184] FIG. 6(a) is a schematic diagram illustrating 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, an optical filter 1404 that transmits light emitted by the light source 1402, and a light diffusion unit 1405. The light source 1402 may include 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 light from the light source, such as for illumination, and deliver the light over a wide area. The optical filter 1404 and the light diffusion unit 1405 may be provided on the light emission side of the lighting. If necessary, a cover may be provided on the outermost surface.

[0185] The lighting device is, for example, a device that illuminates a room. The lighting device may emit white, daylight white, or any other color from blue to red. It may have a dimming circuit that dims these colors. The lighting device may have 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. Furthermore, white has a color temperature of 4200K, and daylight white has a color temperature of 5000K. The lighting device may have a color filter.

[0186] The lighting device according to this embodiment may also include a heat dissipation unit, which dissipates heat from within the device to the outside, and may be made of a material such as a metal with a high specific heat capacity or liquid silicon.

[0187] 6(b) is a schematic diagram of an automobile, which is an example of a moving body according to this embodiment. The automobile has tail lamps, which are an example of lighting fixtures. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking or the like is performed.

[0188] The tail lamp 1501 may include an organic light-emitting element according to this embodiment. The tail lamp 1501 may include a protective member for protecting the organic light-emitting element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0189] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window 1502 may be a transparent display as long as it is not a window for checking the front and rear of the automobile. The transparent display may have an organic light-emitting element according to this embodiment. In this case, the constituent materials of the electrodes and the like of the organic light-emitting element are made of transparent materials.

[0190] The moving body according to this embodiment may be a ship, an aircraft, a drone, or the like. The moving 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 the organic light-emitting element according to this embodiment.

[0191] An application example of the display device of each of the above-described embodiments will be described with reference to Fig. 7. The display device can be applied to a system that can be attached as a wearable device, such as smart glasses, an HMD, or a smart contact lens. The image capturing and display device used in such an application example includes an image capturing device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

[0192] Fig. 7(a) is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention. Using Fig. 7(a), glasses 1600 (smart glasses) according to one application example will be described. An imaging device 1602 such as a CMOS sensor or SPAD is provided on the front side of a lens 1601 of the glasses 1600. In addition, a display device according to each of the above-mentioned embodiments is provided on the back side of the lens 1601.

[0193] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the display device. The control device 1603 also controls the operations of the image capture device 1602 and the display device. The lens 1601 is formed with an optical system for focusing light onto the image capture device 1602.

[0194] FIG. 7(b) is a schematic diagram showing another example of a wearable device according to an embodiment of the present invention. Using FIG. 7(b), glasses 1610 (smart glasses) according to one application example will be described. The glasses 1610 have a control device 1612, which is equipped with an imaging device corresponding to the imaging device 1602 in FIG. 7(a) and a display device. A lens 1611 is formed with an optical system for projecting light emitted from the imaging device in the control device 1612 and the display device, and an image is projected onto the lens 1611. The control device 1612 functions as a power source that supplies power to the imaging device and the display device, and also controls the operation of the imaging device and the display device.

[0195] The control device 1612 may include a gaze detection unit that detects the wearer's gaze. The gaze detection may use infrared light. The infrared light emitter emits infrared light toward the eyeball of the user gazing at the display image. An imaging unit with a light-receiving element detects the reflected infrared light from the eyeball, thereby obtaining a captured image of the eyeball. A reduction unit that reduces light from the infrared light emitter to the display unit in a planar view reduces degradation of image quality. The user's gaze toward the displayed image is detected from the captured image of the eyeball obtained by capturing infrared light. Any known method can be applied to gaze detection using the captured image of the eyeball. As an example, a gaze detection method based on a Purkinje image formed by reflection of irradiated light on the cornea can be used. More specifically, gaze detection processing based on the pupil-corneal reflex method is performed. Using the pupil-corneal reflex method, a gaze vector representing the orientation (rotation angle) of the eyeball is calculated based on the image of the pupil and the Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0196] A display device according to one embodiment of the present invention may include an imaging device having a light receiving element, and may control the display image of the display device based on user line-of-sight information from the imaging device. Specifically, the display device determines a first field of view area where the user gazes and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. 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.

[0197] The display area includes a first display area and a second display area different from the first display area, and a high-priority area is determined from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. The resolution of the high-priority area may be controlled to be higher than the resolution of areas other than the high-priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0198] Note that AI may be used to determine the first field of view area and areas with high priority. The AI ​​may be a model configured to estimate the angle of gaze and the distance to an object in the line of sight from an image of the eyeball, using as training data an image of the eyeball and the direction in which the eyeball in the image was actually looking. The AI ​​program may be included in the display device, the imaging device, or an external device. If included in an external device, it is transmitted to the display device via communication.

[0199] When display control is performed based on visual recognition detection, the smart glasses can be preferably applied to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured external information in real time.

[0200] 8(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 40 is an electrophotographic image forming apparatus and includes a photoconductor 27, an exposure light source 28, a charging unit 30, a developing unit 31, a transfer unit 32, a transport roller 33, and a fixing unit 35. Light 29 is irradiated from the exposure light source 28, and an electrostatic latent image is formed on the surface of the photoconductor 27. The exposure light source 28 includes the organic light-emitting element according to this embodiment. The developing unit 31 includes toner and the like. The charging unit 30 charges the photoconductor 27. The transfer unit 32 transfers the developed image to a recording medium 34. The transport roller 33 transports the recording medium 34. The recording medium 34 is, for example, paper. The fixing unit 35 fixes the image formed on the recording medium 34.

[0201] 8(b) and 8(c) are diagrams showing an exposure light source 28 and are schematic diagrams illustrating a state in which multiple light-emitting units 36 are arranged on a long substrate. Arrow 37 indicates the direction parallel to the axis of the photoconductor, the column direction in which the organic light-emitting elements are arranged. This column direction is the same as the axis direction about which the photoconductor 27 rotates. This direction can also be referred to as the long axis direction of the photoconductor 27. FIG. 8(b) shows a configuration in which the light-emitting units 36 are arranged along the long axis direction of the photoconductor 27. FIG. 8(c) shows a configuration different from FIG. 8(b), in which the light-emitting units 36 are arranged alternately in the column direction in the first and second columns. The first and second columns are arranged at different positions in the row direction. In the first column, multiple light-emitting units 36 are arranged at intervals. In the second column, light-emitting units 36 are located at positions corresponding to the intervals between the light-emitting units 36 in the first column. In other words, multiple light-emitting units 36 are also arranged at intervals in the row direction. The arrangement in FIG. 8(c) can also be described as a grid arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0202] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to provide a stable display with good image quality even over a long period of time. [Example]

[0203] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0204] [Example 1 (Synthesis of Exemplary Compound A4)] (Reference example) [ka]

[0205] (1) Synthesis of compound m-3 The following reagents and solvents were placed in a 100 ml recovery flask. Compound m-1: 1.0g (2.7mmol) Compound m-2: 0.2g (3.3mmol) Ethanol: 20ml Acetic acid: 20 ml Next, the reaction solution was heated under reflux and stirred under a nitrogen stream for 6 hours. Next, acetic acid was added, and the mixture was refluxed and stirred under a nitrogen stream for 6 hours. After the reaction was completed, water and toluene were added and the mixture was separated. The toluene solution was concentrated and washed with methanol to obtain 0.69 g (yield: 65%) of compound m-3 as a yellow solid.

[0206] (2) Synthesis of compound m-5 The following reagents and solvents were placed in a 100 ml recovery flask. Compound m-3: 0.5g (1.3mmol) Compound m-4: 0.9g (2.8mmol) Pd(PPh3)4: 0.05g Toluene: 15 ml Ethanol: 8ml 2M sodium carbonate solution: 8 ml The reaction solution was then heated under reflux under a nitrogen atmosphere for 6 hours. After the reaction was completed, water and toluene were added and the mixture was separated. The mixture was purified by column chromatography (toluene:heptane) and recrystallized from toluene to obtain 0.6 g (yield: 80%) of compound m-5 as a pale yellow solid.

[0207] (3) Synthesis of Compound A4 The following reagents and solvents were placed in a 200 ml recovery flask. Compound m-5: 0.4g (0.65mmol) Compound m-6: 0.3g (1.4mmol) Pd(dba)2: 0.011g Sphos: 0.024g Potassium phosphate: 0.34g Toluene: 12 ml Ethanol: 6 ml Water: 6ml Next, the reaction solution was heated under reflux and stirred under a nitrogen stream for 6 hours. After the reaction was completed, the solution was filtered, dissolved in xylene, and washed with silica gel adsorption. The solvent was then concentrated, and the slurry was washed with methanol. After filtration, 0.45 g (yield: 81%) of Example Compound A4 was obtained as a white solid.

[0208] The exemplary compound A4 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF manufactured by Bruker). [MALDI-TOF-MS] Measured value: m / z=867 Calculated value: C 64 H 38 N2O2=867

[0209] [Examples 2 to 20 (Synthesis of Exemplary Compounds)] (Examples 2 to 11 are reference examples) As shown in Tables 4 and 5, the exemplary compounds shown in Examples 2 to 20 were synthesized in the same manner as in Example 1, except that the raw materials m-2 and m-6 in Example 1 were changed. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 1 are also shown.

[0210] [Table 4]

[0211] [Table 5]

[0212] [Example 21] (Reference example) An organic light-emitting device with a bottom emission structure was fabricated by sequentially forming an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode on a substrate.

[0213] First, an ITO film was formed on a glass substrate and then patterned as desired to form an ITO electrode (anode). At this time, the film thickness of the ITO electrode was set to 100 nm. The substrate on which the ITO electrode was formed was used as the ITO substrate in the following process. Next, a 1.33 × 10 -4 Vacuum deposition was performed by resistance heating in a vacuum chamber at 100 Pa to successively form the organic compound layer and electrode layer shown in Table 6 on the ITO substrate. At this time, the electrode area of ​​the opposing electrode (metal electrode layer, cathode) was 3 mm 2 It was made to be like this.

[0214] [Table 6]

[0215] The characteristics of the obtained device were measured and evaluated. The maximum emission wavelength of the light-emitting device was 522 nm, and the maximum external quantum efficiency (EQE) was 1.3, where the EQE of Comparative Example 1 was 1.0. Furthermore, at a current density of 100 mA / cm 2 A continuous driving test was carried out at 1000 rpm, and the time (LT95) at which the luminance degradation rate reached 5% was measured. The luminance degradation rate ratio was 1.4, with Comparative Example 1 being taken as 1.0. In this example, the measuring device was specifically a microcurrent meter 4140B manufactured by Hewlett-Packard Company, and the luminance was measured by a BM7 manufactured by Topcon Corporation.

[0216] [Examples 22 to 41, Comparative Example 1] (Examples 22 to 27, 38 to 40 are reference examples) An organic light-emitting device was produced in the same manner as in Example 21, except that the compounds were appropriately changed to those shown in Table 7. The characteristics of the obtained device were measured and evaluated in the same manner as in Example 21. The measurement results are shown in Table 7. Comparative compound 1-A used as the host material in Comparative Example 1 is compound 1-A described in Patent Document 1.

[0217] [Table 7]

[0218] As can be seen from Table 7, the maximum external quantum efficiency (EQE) of each example exceeded 1.0 compared to that of Comparative Example 1, and the light-emitting devices of the examples had higher luminous efficiency. This is because the compounds according to this embodiment have larger S1 and T1. Furthermore, the light-emitting devices according to the examples had a longer life. This is because the compounds according to this embodiment have better filmability and sublimation properties. From the above, by using the compounds according to this embodiment, it is possible to provide devices that are highly efficient and have excellent durability characteristics.

[0219] [Example 42] (Reference example) An organic light-emitting device was produced in the same manner as in Example 21, except that the organic compound layer and the electrode layer shown in Table 8 were successively formed.

[0220] [Table 8]

[0221] The device characteristics were measured and evaluated for the obtained device. The light-emitting device emitted green light. In addition, the time (LT95) until the luminance degradation rate reached 5% was measured in the same manner as in Example 21, and the luminance degradation rate ratio was 1.8, with Comparative Example 2 being 1.0.

[0222] [Examples 43 to 50, Comparative Example 2] (Examples 43 to 46 are reference examples) An organic light-emitting device was produced in the same manner as in Example 42, except that the compounds were appropriately changed to those shown in Table 9. The characteristics of the obtained device were measured and evaluated in the same manner as in Example 42. The measurement results are shown in Table 9.

[0223] [Table 9] [Explanation of symbols]

[0224] 1: interlayer insulating layer, 2: first electrode, 3: insulating layer, 4: organic compound layer, 5: second electrode, 6: protective layer, 7: color filter, 10: subpixel, 11: substrate, 12: insulating layer, 13: gate electrode, 14: gate insulating film, 15: semiconductor layer, 16: drain electrode, 17: source electrode, 18: TFT, 19: insulating film, 20: contact hole, 21: anode, 22: organic compound layer, 23: cathode, 24: first protective layer, 25: second protective layer, 26: organic light-emitting element, 100: display device

Claims

1. An organic compound represented by the following general formula [1]: 【Chemistry 1】 In formula [1], R 1 ~R 8 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted heterocyclic group, and a cyano group. A has the structure shown below as A, and is bonded at the position indicated by *. 【Chemistry 2】 In the above A, B is selected from the structures shown in [B-7] to [B-15] below, and is bonded at the position indicated by *. 【Transformation 3】 In the above [B-7] to [B-15], R 9 ~R 17 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted heterocyclic group, and a cyano group.

2. 2. The organic compound according to claim 1, wherein B is selected from the structures shown in [C-1] to [C-3] below. 【Chemistry 4】

3. an anode and a cathode, an organic compound layer disposed between the anode and the cathode, An organic light-emitting device, wherein at least one of the organic compound layers contains the organic compound according to claim 1 or 2.

4. 4. The organic light-emitting device according to claim 3, wherein the organic compound layer containing the organic compound is a light-emitting layer.

5. 5. The organic light-emitting element according to claim 4, wherein the light-emitting layer further contains a phosphorescent material, and the content of the organic compound is 30% by mass or more and 99% by mass or less.

6. 6. The organic light-emitting element according to claim 5, wherein the phosphorescent material is an organometallic complex having a ligand having at least three or more fused rings.

7. 7. The organic light-emitting element according to claim 6, wherein the fused rings having three or more rings are any one of a triphenylene ring, a phenanthrene ring, a benzofluorene ring, a dibenzofuran ring, a dibenzothiophene ring, a benzoisoquinoline ring, and a naphthoisoquinoline ring.

8. The organic light-emitting device according to claim 5 , wherein the light-emitting layer further contains a third component.

9. The organic light-emitting element according to claim 8 , wherein the third component has at least a carbazole skeleton.

10. The organic light-emitting element according to claim 8 , wherein the third component has at least an azine ring in its skeleton.

11. The organic light-emitting device according to claim 8 , wherein the third component has at least xanthone in its skeleton.

12. 12. The organic light-emitting element according to claim 4, further comprising another light-emitting layer disposed in a stacked state with the light-emitting layer, the another light-emitting layer emitting light of a color different from the color of light emitted by the light-emitting layer.

13. The organic light-emitting device according to claim 12, which emits white light.

14. A display device comprising a plurality of pixels, at least one of the plurality of pixels comprising the organic light-emitting element according to claim 3 and a transistor connected to the organic light-emitting element.

15. an optical unit having a plurality of lenses, an image pickup element that receives light that has passed through the optical unit, and a display unit that displays an image picked up by the image pickup element; The photoelectric conversion device, wherein the display section comprises the organic light-emitting element according to claim 3 .

16. 14. An electronic device comprising: a display unit having the organic light-emitting element according to claim 3; a housing in which the display unit is provided; and a communication unit provided in the housing and communicating with an external device.

17. 14. A lighting device comprising: a light source having the organic light-emitting element according to claim 3; and a light diffusion section or an optical filter that transmits light emitted by the light source.

18. A moving body comprising: a lamp having the organic light-emitting element according to claim 3; and a vehicle on which the lamp is provided.

19. An exposure light source for an electrophotographic image forming apparatus, comprising the organic light-emitting element according to claim 3 .

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