Organic compound, organic light emitting element, display device, photoelectric conversion device, electronic apparatus, illumination device, moving body, and exposure light source

Abstract

To provide an organic compound excellent in element life characteristics when used in an organic light-emitting element.SOLUTION: The organic compound is represented by general formula [1].SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an organic compound, an organic light-emitting device, a display device, a photoelectric conversion device, an electronic device, a lighting device, a mobile object, and an exposure light source. [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 the electrodes. By injecting electrons and holes from the 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.

[0003] Recent progress in organic light-emitting devices has been remarkable, and their features include low driving voltage, a wide range of emission wavelengths, high-speed response, and the ability to make light-emitting devices thinner and lighter.

[0004] Incidentally, to date, active efforts have been made to create compounds suitable for organic light-emitting devices, because the creation of compounds with excellent device life characteristics is important in providing high-performance organic light-emitting devices.

[0005] As compounds that have been created so far, the following compound 1-A is described in Patent Document 1, and the following compound 1-B is described in Patent Document 2. Both are compounds in which a fused polycyclic group is substituted at the end of a phenylene chain.

[0006] [ka] [Prior art documents] [Patent documents]

[0007] [Patent Document 1] International Publication No. 2006 / 130598 [Patent Document 2] International Publication No. 2012 / 050008 Summary of the Invention [Problem to be solved by the invention]

[0008] The present inventors have examined Compound 1-A described in Patent Document 1 and Compound 1-B described in Patent Document 2 and found that there is room for improvement in the element life characteristics when used in an organic light-emitting element.

[0009] In view of the above-mentioned problems, an object of the present invention is to provide an organic compound that exhibits excellent element life characteristics when used in an organic light-emitting device. Another object of the present invention is to provide an organic light-emitting device that exhibits excellent element life characteristics. [Means for solving the problem]

[0010] The organic compound according to one aspect of the present invention is characterized by being represented by the following general formula [1]:

[0011] [ka]

[0012] In the general formula [1], R1 and R2 are each independently selected from the following substituent group A. However, R 1 is a spirofluorene structure, R 2 is not a dibenzofuran structure or a dibenzothiophene structure. (Substituent group A)

[0013] [ka]

[0014] [ka]

[0015] [ka]

[0016] In the above-mentioned substituent group A, R 101 ~R 506 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, an aryloxy group, a silyl group, an aromatic hydrocarbon group, a heterocyclic group, or a cyano group. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide an organic compound that has excellent device life characteristics when used in an organic light-emitting device. [Brief explanation of the drawings]

[0018] [Figure 1] 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 2] 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Figure 3] 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 a portable device according to an embodiment of the present invention. [Figure 4] 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 5] 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 automobile as an example of a moving body according to an embodiment of the present invention. [Figure 6] 1A and 1B are schematic diagrams illustrating an example of a wearable device according to an embodiment of the present invention, each of which has an imaging device; [Figure 7]1 is a schematic diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Figure 8] FIG. 2 is a schematic diagram illustrating an example of an exposure light source of the image forming apparatus according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] ≪Organic compounds≫ First, the organic compound according to this embodiment will be described.

[0020] The organic compound according to this embodiment is an organic compound represented by the following general formula [1].

[0021] [ka]

[0022] In the general formula [1], R1 and R2 are each independently selected from the following substituent group A. (Substituent group A)

[0023] [ka]

[0024] [ka]

[0025] [ka]

[0026] In the substituent group A, R 101 ~R 506 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, an aryloxy group, a silyl group, an aromatic hydrocarbon group, a heterocyclic group, and a cyano group. In the general formula [1], it is preferable that at least one of R1 and R2 is independently selected from the following substituent group B. (Substituent group B)

[0027] [ka]

[0028] In the above-mentioned substituent group B, R 701 ~R 746 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, an aryloxy group, a silyl group, an aromatic hydrocarbon group, a heterocyclic group, and a cyano group.

[0029] In the general formula [1], it is preferable that at least one of R1 and R2 is independently selected from the following substituent group C. (Substituent group C)

[0030] [ka]

[0031] In the substituent group C, R 801 ~R 868 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, an aryloxy group, a silyl group, an aromatic hydrocarbon group, a heterocyclic group, and a cyano group.

[0032] Furthermore, in the general formula [1], it is particularly preferable that at least one of R1 and R2 is independently selected from the following substituent group D. (Substituent group D)

[0033] [ka]

[0034] In the above-mentioned substituent group D, R 901 ~R 918 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, an aryloxy group, a silyl group, an aromatic hydrocarbon group, a heterocyclic group, and a cyano group.

[0035] R 101 ~R 506 , R 701 ~R 746 , R 801 ~R 868 , R 901 ~R 918 Examples of the halogen atom represented by the formula (I) include, but are not limited to, fluorine, chlorine, bromine, and iodine.

[0036] R 101 ~R 506 , R 701 ~R 746 , R 801 ~R 868 , R 901 ~R 918 Examples of the alkyl group represented by the formula (I) 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, and a 2-adamantyl group.

[0037] R 101 ~R 506 , R 701 ~R 746 , R 801 ~R 868 , R 901 ~R 918 Examples of the alkoxy group represented by the formula (I) include, but are not limited to, a methoxy group, an ethoxy group, a propoxy group, a 2-ethyl-octyloxy group, and a benzyloxy group.

[0038] R 101 ~R506 , R 701 ~R 746 , R 801 ~R 868 , R 901 ~R 918 Examples of the amino group represented by the formula (I) include 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, but are not limited to these.

[0039] R 101 ~R 506 , R 701 ~R 746 , R 801 ~R 868 , R 901 ~R 918 Examples of the aryloxy group and heteroaryloxy group represented by the formula (I) include, but are not limited to, a phenoxy group and a thienyloxy group.

[0040] R 101 ~R 506 , R 701 ~R 746 , R 801 ~R 868 , R 901 ~R 918 Examples of the silyl group represented by the formula (I) include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0041] R 101 ~R 506 , R 701 ~R 746 , R801 ~R 868 , R 901 ~R 918 Examples of the aromatic hydrocarbon group represented by the formula (I) include, but are not limited to, a phenyl group, a naphthyl group, an indenyl group, a biphenyl group, a terphenyl group, a fluorenyl group, a phenanthryl group, a fluoranthenyl group, and a triphenylenyl group.

[0042] R 101 ~R 506 , R 701 ~R 746 , R 801 ~R 868 , R 901 ~R 918 Examples of the heterocyclic group represented by the formula (I) include, but are not limited to, a pyridyl group, an oxazolyl group, an oxadiazolyl group, a thiazolyl group, a thiadiazolyl group, a carbazolyl group, an acridinyl group, a phenanthrolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group.

[0043] Examples of substituents that may be further substituted by the alkyl group, alkoxy group, amino group, aryloxy group, silyl group, aromatic hydrocarbon group, and heterocyclic group include, but are not limited to, halogen atoms such as fluorine, chlorine, bromine, and iodine; alkyl groups such as methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, and tertiary butyl group; alkoxy groups such as methoxy group, ethoxy group, and propoxy group; amino groups such as dimethylamino group, diethylamino group, dibenzylamino group, diphenylamino group, and ditolylamino group; aryloxy groups such as phenoxy group; aromatic hydrocarbon groups such as phenyl group and biphenyl group; heterocyclic groups such as pyridyl group and pyrrolyl group; and cyano group.

[0044] (Method for synthesizing organic compounds) 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.

[0045] [ka]

[0046] Here, various compounds can be obtained by appropriately changing the compounds shown in (d) and (f) above. The present invention 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.

[0047] (Characteristics of the organic compound according to this embodiment) Next, the characteristics of the organic compound according to this embodiment will be described.

[0048] The organic compound according to this embodiment has the following characteristics, resulting in a small ΔST, which is the energy difference between S1 (excited singlet state) and T1 (excited triplet state). Furthermore, the organic compound has the following characteristics, resulting in excellent amorphous properties. Furthermore, the organic compound has the following characteristics, resulting in excellent sublimation properties. Furthermore, by using this organic compound, an organic light-emitting device excellent in luminous efficiency and device durability can be provided. (1) The 4- and 3-positions of the 1,1':3',1"-terphenyl have substituents consisting of three or more fused rings, resulting in a small ΔST. (2) The 1,1':3',1"-terphenyl has substituents consisting of three or more fused rings at the 4- and 3"-positions, resulting in low symmetry. (3) The compound is highly stable because it has no substituents other than the 4- and 3-positions of the 1,1':3',1"-terphenyl. These features will be explained below with reference to comparative compounds 1-A to 1-C.

[0049] (1) The 4- and 3-positions of the 1,1':3',1"-terphenyl have substituents consisting of three or more fused rings, resulting in a small ΔST. In developing the organic compound of the present invention, the inventors focused on the structure of the linking group consisting of a phenylene chain. The organic compound of this embodiment has a structure in which substituents consisting of three or more fused rings are present at the 4- and 3-positions of a 1,1':3',1"-terphenyl. In other words, the organic compound of this embodiment has a structure in which two fused rings are linked by a 1,1':3',1"-terphenyl linking group. By having a 1,1':3',1"-terphenyl linking group, the S1 energy level of the organic compound is reduced and the T1 energy level is increased. As a result, ΔST (=S1 - T1) of the organic compound is reduced.

[0050] Table 1 shows the results of comparing the S1 energy level and T1 energy level of Exemplary Compound A4, which is an example of an organic compound according to this embodiment, with Comparative Compounds 1-A and 1-B. The S1 energy level was measured by photoluminescence (PL) measurement of a vapor-deposited film at room temperature and an excitation wavelength of 350 nm using a Hitachi F-4500, and calculated from the rising edge of the emission spectrum. The T1 energy level was measured by photoluminescence (PL) measurement of a vapor-deposited film at 77 K and an excitation wavelength of 350 nm using a Hitachi F-4500, and calculated from the rising edge of the emission spectrum on the short wavelength side. The S1 and T1 energy levels were measured using a 5×10 -4 The deposited film sample was prepared by depositing the film on a quartz substrate at a vacuum of 1000 kJ / cm2 or less.

[0051] [Table 1]

[0052] As shown in Table 1, the SI energy level of the exemplary compound A4 was 3.28 eV, the T1 energy level was 2.50 eV, and ΔST was 0.78 eV. On the other hand, the SI energy level of the comparative compound 1-A was 3.46 eV, the T1 energy level was 2.50 eV, and ΔST was 1.04 eV. Furthermore, the SI energy level of the comparative compound 1-B was 3.48 eV, the T1 energy level was 2.52 eV, and ΔST was 1.06 eV. As such, it can be seen that the ΔST of the exemplary compound A4 is smaller than that of the comparative compounds 1-A and 1-B.

[0053] This is thought to be due to the structure in which the two fused rings are linked at the 4- and 3-positions of the 1,1':3',1"-terphenyl linking group. The 1,1':3',1"-terphenyl, which links the two structures at the 4- and 3-positions, has three phenylene chains, as shown below. Of the three phenylene chains, one is linked at the p-position (the area enclosed in a dashed square below), and the other two are linked at the m-position (the area enclosed in a dashed circle below). The phenylene chains linked at the p-position extend the conjugation, lowering the S1 energy level. On the other hand, the phenylene chains linked at the m-position shorten the conjugation, allowing a high T1 energy level to be maintained.

[0054] [ka]

[0055] Here, the effect of a small ΔST will be described.

[0056] In organic light-emitting devices that utilize phosphorescence, the T1 of the phosphorescent material (guest) that emits phosphorescence is used for light emission. Therefore, the host material of the light-emitting layer of an organic light-emitting device that utilizes phosphorescence needs to have a higher T1 energy level than the phosphorescent material (guest).

[0057] Generally, as the T1 energy level increases, the S1 energy level also tends to increase accordingly. A high S1 energy level means a large band gap. A large band gap reduces the injection of holes and electrons from the surrounding layers of the light-emitting layer. This can result in a high device voltage and a decrease in device durability due to unnecessary charge accumulation. Therefore, from the perspective of increasing the injection of holes and electrons from the surrounding layers of the light-emitting layer, a low S1 energy level is preferable.

[0058] Therefore, a host material for the light-emitting layer of an organic light-emitting device that utilizes phosphorescence preferably has a high T1 energy level and a low S1 energy level, i.e., an organic compound with a small ΔST (=S1-T1) is preferred.

[0059] As described above, the organic compound according to this embodiment has a linking group of 1,1':3',1"-terphenyl and substituents at the 4- and 3"-positions, and therefore has a small ΔST. Therefore, when this organic compound is used as a host material in the light-emitting layer of an organic light-emitting device, it can be driven at a low voltage and has excellent device life characteristics. In addition, it also has excellent luminous efficiency.

[0060] (2) The 1,1':3',1"-terphenyl has substituents consisting of three or more fused rings at the 4- and 3"-positions, resulting in low symmetry. In developing the organic compound of the present invention, the present inventors focused on the symmetry of organic compounds. The organic compound according to this embodiment has a structure in which three or more fused rings are bonded to the 4-position and the 3-position of a 1,1':3',1"-terphenyl. Therefore, the organic compound has a structure with low symmetry.

[0061] Table 2 shows the results of a comparison of the symmetry between Exemplary Compound A4, which is an example of an organic compound according to this embodiment, and Comparative Compounds 1-A and 1-B.

[0062] [Table 2]

[0063] As shown in Table 2, Example Compound A4, Comparative Compound 1-A, and Comparative Compound 1-B all have a structure in which two triphenylene rings are linked by a linking group consisting of a phenylene chain. When the molecular structure is viewed in a plane, the symmetry of the molecular structure changes depending on the bonding position of the phenylene chain in the linking group that links the triphenylene rings at both ends.

[0064] As shown in Table 2, Comparative Compounds 1-A and 1-B have a structure with two-fold rotational symmetry about an axis that passes through the middle of the two phenylene chains that constitute the linking group and is perpendicular to the molecular plane, and therefore have high symmetry. On the other hand, Exemplary Compound A4 has a planar structure without an axis of rotation or symmetry, and therefore has lower symmetry than Comparative Compounds 1-A and 1-B.

[0065] The low symmetry of the compound has the following effects.

[0066] The first effect is that molecular packing, where molecules overlap each other, can be suppressed, making the material less likely to crystallize and increasing its amorphous nature. High amorphous nature, or in other words, good film properties, are desirable when used in organic light-emitting devices.

[0067] This is because the high amorphousness makes it difficult for grain boundaries, trap levels, and quenchers to be generated due to microcrystallization even during device operation, and therefore good carrier transport properties and highly efficient light-emitting properties can be maintained, resulting in an organic light-emitting device with excellent durability and efficiency.

[0068] Here, the glass transition temperatures and crystallization temperatures of Exemplary Compound A4, which is an example of the organic compound according to this embodiment, and Comparative Compound 1-A and Comparative Compound 1-B were evaluated by differential scanning calorimetry (DSC) measurement. The results are shown in Table 2.

[0069] The higher the glass transition temperature, and the higher or no crystallization temperature, the more amorphous the material and the better its thermal stability. For DSC measurements, 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 heating at a rate of 10°C / min. The measurement device used was a DSC 204 F1 manufactured by NETZSCH.

[0070] Comparative compound 1-A had a glass transition temperature of 130° C., and a crystallization temperature was observed during heating at 218° C. In other words, it can be said that comparative compound 1-A is a compound with low amorphousness and low thermal stability.

[0071] On the other hand, in the case of Example Compound A4, the glass transition temperature was 141°C, and no crystallization temperature was observed during the temperature rise. In other words, Example Compound A4 is a compound with high amorphousness and excellent thermal stability. Therefore, by using Example Compound A4 in an organic light-emitting device, a stable amorphous film can be maintained even during device operation, and an organic light-emitting device with a long life can be provided.

[0072] The second effect is that the sublimation temperature can be lowered and the sublimation property can be improved.

[0073] This is because when the symmetry of the compound is low, the organic compounds are less likely to aggregate with each other. Table 3 shows the results of comparing the sublimation properties of Exemplary Compound A4, which is an example of the organic compound according to this embodiment, with Comparative Compound 1-B.

[0074] The sublimation property was evaluated by the temperature difference ΔT between the sublimation temperature and the decomposition temperature (= decomposition temperature - sublimation temperature). The larger this temperature difference, the higher the sublimation property. The decomposition temperature was determined by TG / DTA measurement and the temperature at which the weight loss reached 5% was taken as the decomposition temperature. The sublimation temperature was determined by the temperature difference ΔT between the sublimation temperature and the decomposition temperature. -1The temperature was slowly raised under a vacuum of 0.1 Pa while flowing Ar, and sublimation purification was carried out. The temperature at which a sufficient sublimation rate was reached was taken as the sublimation temperature.

[0075] [Table 3]

[0076] As shown in Table 3, although exemplary compound A4 and comparative compound 1-B have the same molecular weight, exemplary compound A4 has a larger temperature difference ΔT between the sublimation temperature and the decomposition temperature, indicating that it is a material with higher sublimability.

[0077] High sublimability allows stable sublimation purification without decomposition during sublimation. High sublimability also provides high vapor deposition stability during the preparation of organic light-emitting devices. This means that a highly pure vapor-deposited film can be prepared without decomposition during vapor deposition, providing a long-life organic light-emitting device.

[0078] (3) The compound is highly stable because it has no substituents other than the 4- and 3-positions of the 1,1':3',1"-terphenyl. In inventing the organic compound of the present invention, the inventors focused on the structure of a linker consisting of a phenylene chain. Specifically, the organic compound of this embodiment has a structure in which two fused rings are linked by a linking group, 1,1':3',1"-terphenyl. Here, in this embodiment, the linking group, 1,1':3',1"-terphenyl, is characterized in that it has no substituents other than the fused rings at the 4- and 3"-positions. By adopting such a structure, the compound is stable because it does not have any substituents that would increase the bond distance.

[0079] For example, as shown in Table 4, the maximum bond distance of Example Compound A4, which is an example of an organic compound according to this embodiment, is compared with that of Comparative Compound 1-C. Comparative Compound 1-C is a compound in which the 1,1':3',1"-terphenyl linking group of Example Compound A4 has substituents (methyl groups) at positions other than the 4- and 3-positions.

[0080] [Table 4]

[0081] In Table 4, the bond with the longest bond distance in each compound is represented by a. The maximum bond distance in the case of Example Compound A4 is 1.485 Å, while the maximum bond distance in the case of Comparative Compound 1-C is 1.494 Å. Having a substituent that increases the maximum bond distance like this is undesirable because bonds with long bond distances are prone to cleavage, leading to a decrease in drive durability. In other words, a short maximum bond distance can improve drive durability.

[0082] The bond distances were calculated using molecular orbital calculations. The currently widely used density functional theory (DFT) was used as the molecular orbital calculation method. The functional was B3LYP, and the basis set was 6-31G. *It is also a smooth-flowing multi-layer graph with Gaussian09(Gaussian09). ,RevisionC.01,MJFrisch,GWTrucks,HBSchlegel,GEScus area, MARobb, JRCheeseman, G. Scalmani, V. Barone, B. Mennucci, G. Petersson, H. Nakatsuji, M. Caricato, X. Li, HPHr atchian, AFIzmaylov, J. Bloino, G. Zheng, JLSonnenberg, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ish ida,T.Nakajima,Y.Honda,O.Kitao,H.Nakai,T.Vreven,JAMontgomery,Jr.,JEPeralta,F.Ogliaro,M.Bearpark,JJH eyd, E. Brothers, KNKudin, VNStaroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, JCBuran t,SSIyengar,J.Tomasi,M.Cossi,N.Rega,JMMillam,M.Klene,JEKnox,JBCross,V.Bakken,C.Adamo,J.Jaramillo,R. Gomperts,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.)

[0083] The evaluation of the light-emitting characteristics and sublimation properties listed as the characteristics (1) to (3) of the organic compound according to this embodiment will be described in more detail in the examples described later.

[0084] Furthermore, the organic compound according to this embodiment can be particularly suitably used in an organic light-emitting device when it further has the following characteristics: Note that a plurality of the following characteristics may be satisfied simultaneously. (4) The fused ring represented by R1 and R2 does not have an sp3 carbon atom. (5) Each of the fused rings represented by R1 and R2 is bonded to the linking group at a substitution position where interference due to steric hindrance is suppressed. These features will be explained below.

[0085] (4) The fused ring represented by R1 and R2 does not have an sp3 carbon atom. In the organic compound according to this embodiment, the fused rings at both ends preferably do not have sp3 carbons. The absence of sp3 carbons in the fused rings represented by R1 and R2 eliminates the inclusion of carbon-carbon bonds with low bond energy, making bond cleavage less likely to occur during operation of the organic light-emitting device. Therefore, when used in an organic light-emitting device, the device life characteristics can be improved.

[0086] Specifically, the fused rings represented by R1 and R2 are preferably each independently selected from triphenylene, phenanthrene, chrysene, dibenzofuran, dibenzothiophene, and azatriphenylene.

[0087] (5) Each of the fused rings represented by R1 and R2 is bonded to the linking group at a substitution position where interference due to steric hindrance is suppressed. In the organic compound according to this embodiment, the fused rings represented by R1 and R2 and the linking group are preferably bonded at substitution positions where interference due to steric hindrance is suppressed. This is because, by bonding the fused rings and the linking group at substitution positions where interference due to steric hindrance is suppressed, the bond distance between the fused rings and the linking group can be reduced. The reduced bond distance makes the bond less susceptible to cleavage, resulting in a stable bond. As a result, bond cleavage is less likely to occur during operation of the organic light-emitting element, and the element life characteristics can be improved when used in the organic light-emitting element.

[0088] Table 5 shows the results of a comparison of the bond distances between Exemplary Compound A4 and Exemplary Compound A3.

[0089] [Table 5]

[0090] In Table 5, the bond with the longest bond distance in each compound is represented by a. The maximum bond distance in Example Compound A4 is 1.485 Å, while the maximum bond distance in Example Compound A3 is 1.492 Å. This is because the bond distance between the phenanthrene ring and the linking group increases due to the steric hindrance of the hydrogen atom at the peri-position of the phenanthrene ring. The stability of bond a, which is the bond with the longest bond distance, is higher in Example Compound A4 than in Example Compound A3. Therefore, Example Compound A4 can improve the device life characteristics when used in an organic light-emitting device compared to Example Compound A3.

[0091] Specific examples of the organic compound according to this embodiment are shown below, but the present invention is not limited to these.

[0092] [ka]

[0093] [ka]

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] Of the above exemplary compounds, the exemplary compounds (A1 to A42) belonging to group A are compounds in which the skeleton of the fused ring represented by R1 and R2 is an aromatic hydrocarbon, and the skeleton of the fused ring is composed of sp2 carbons.

[0102] These compounds are particularly stable among the compounds represented by general formula [1] because the skeleton of the fused ring is composed of sp2 hybrid orbitals. In particular, when the fused rings represented by R1 and R2 are triphenylene rings or phenanthrene rings, T1 becomes high, which is preferable. From the viewpoint of bond stability, it is more preferable that at least one of the fused rings represented by R1 and R2 is a triphenylene ring and is bonded to a linking group at the 2-position of the triphenylene ring. Alternatively, from the viewpoint of bond stability, it is more preferable that at least one of the fused rings represented by R1 and R2 is a phenanthrene ring and is bonded to a linking group at the 2-position or 3-position of the phenanthrene ring.

[0103] Of the above exemplary compounds, the exemplary compounds (B1 to B42) belonging to group B are compounds containing a dibenzofuran ring or a dibenzothiophene ring in the fused ring represented by R1 and R2.

[0104] These compounds contain oxygen atoms and sulfur atoms in the fused rings represented by R1 and R2, and the abundant unshared electron pairs possessed by these atoms can enhance charge transport properties, making them particularly easy to adjust the carrier balance. From the viewpoint of bond stability, it is preferable that at least one of the fused rings represented by R1 and R2 and the linking group be bonded to any one of the 2-, 3-, or 4-positions of the dibenzofuran ring or dibenzothiophene ring.

[0105] Of the above exemplary compounds, the exemplary compounds (C1 to C42) belonging to group C are compounds containing a fluorene ring in the fused ring represented by R1 and R2.

[0106] These compounds further have a substituent at the 9-position of the fluorene. This allows the substituent to be oriented 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.

[0107] Of the above exemplary compounds, the exemplary compounds (D1 to D60) belonging to group D are compounds containing an azine ring in the fused ring represented by R1 and R2.

[0108] These compounds contain N atoms in the fused rings, and therefore the charge transport properties can be enhanced by the unshared electron pair of the N atoms and their high electronegativity, making them particularly easy to adjust the carrier balance.

[0109] <Organic light-emitting element> Next, the organic light-emitting device according to this embodiment will be described.

[0110] Specific examples of the organic light-emitting device according to this embodiment include a multilayer device configuration in which electrode layers and organic compound layers shown in (a) to (f) below are sequentially stacked on a substrate. That is, the organic light-emitting device according to this embodiment has at least a pair of electrodes, an anode and a cathode, and an organic compound layer disposed between these electrodes. In any device configuration, the organic compound layer always includes a light-emitting layer containing a light-emitting material. (a) Anode / Emitting layer / Cathode (b) Anode / hole transport layer / light-emitting layer / electron transport layer / cathode (c) Anode / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode (d) Anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / cathode (e) Anode / hole injection layer / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode (f) Anode / hole transport layer / electron blocking layer / light-emitting layer / hole blocking layer / electron transport layer / cathode However, these device configuration examples are merely very basic device configurations, and the device configuration of the organic light-emitting device of the present invention is not limited to these. For example, an insulating layer, adhesive layer, or interference layer may be provided at the interface between the electrode and the organic compound layer. Furthermore, the electron transport layer or hole transport layer may have a multilayer structure having two layers with different ionization potentials. The light-emitting layer may have a multilayer structure having two layers each containing a different light-emitting material. That is, a first light-emitting layer emitting a first light and a second light-emitting layer emitting a second light may be provided between the anode and cathode. By making the first light and the second light different colors, for example, so that they become white when mixed, an organic light-emitting device that emits white light can be obtained. In addition to this, various layer configurations can be adopted.

[0111] In this embodiment, the extraction mode (device configuration) of light output from the light-emitting layer may be a so-called bottom emission type in which light is extracted from the electrode on the substrate side, or a so-called top emission type in which light is extracted from the opposite side of the substrate. Also, a double-sided emission type in which light is extracted from the substrate side and the opposite side of the substrate may be adopted.

[0112] Among the device configurations (a) to (f) above, configuration (f) is preferred because it has both an electron blocking layer (electron blocking layer) and a hole blocking layer (hole blocking layer). In other words, configuration (f) having an electron blocking layer and a hole blocking layer can reliably confine both hole and electron carriers within the light-emitting layer, resulting in an organic light-emitting device with no carrier leakage and high luminous efficiency.

[0113] The organic light-emitting element according to this embodiment includes an organic compound represented by the general formula [1] in an organic compound layer. The organic light-emitting element according to this embodiment preferably includes an organic compound represented by the general formula [1] in an emitting layer. However, the present invention is not limited thereto, and the organic compound may be used as a constituent material for organic compound layers other than the emitting layer that constitute the organic light-emitting element according to this embodiment. Specifically, the organic compound may be used as a constituent material for an electron transport layer, an electron injection layer, an electron blocking layer, a hole transport layer, a hole injection layer, a hole blocking layer, etc.

[0114] In the organic light-emitting device according to this embodiment, when the organic compound represented by general formula [1] is contained in the light-emitting layer, the light-emitting layer may be a layer composed of the organic compound represented by general formula [1] and a second compound that is another compound. Here, when the light-emitting layer is a layer composed of the organic compound represented by general formula [1] and another compound, the organic compound according to this embodiment may be used as a host (also referred to as a host material) or an assist material of the light-emitting layer.

[0115] Here, the host is the compound with the largest mass ratio among the compounds constituting the light-emitting layer. The guest is the compound with a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and is the compound that is primarily responsible for emitting light. The assist material is the compound with a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and assists the guest in emitting light. The assist material is also called the second host. Alternatively, if the host is the first compound and the guest is the second compound, the assist can be called the third compound.

[0116] In addition, the host is preferably a material with a higher LUMO than the guest (a material with a LUMO closer to the vacuum level). This allows electrons supplied to the host in the emitting layer to be efficiently transferred to the guest, improving luminous efficiency. Furthermore, when an assist material is used in addition to the host and guest, the host is preferably a material with a higher LUMO than the assist material (a material with a LUMO closer to the vacuum level). This allows electrons supplied to the host in the emitting layer to be efficiently transferred to the assist material, allowing the assist material to take on exciton recombination. As a result, energy can be efficiently transferred to the guest.

[0117] The energy of the excited singlet state (S1) of the host (singlet energy) is S h1 , the energy of the excited triplet state (T1) (triplet energy) is T h1 The energy of guest S1 is S g1 , the energy of T1 is T g1 In this case, S h1 >S g1 It is preferable to satisfy T h1 >T g1 It is more preferable to satisfy the following. Furthermore, the energy of S1 of the assist material is S a1 , the energy of T1 is T a1 Then, S a1 >S g1 It is preferable to satisfy T a1 >T g1 It is more preferable to satisfy S h1 >S a1 >S g1 It is more preferable to satisfy T h1 >T a1 >T g1 It is more preferable that the following be satisfied.

[0118] The present inventors have conducted various studies and found that when an organic compound represented by general formula [1] is used as a host or an assist in an emitting layer, particularly as an assist in an emitting layer, an organic light-emitting element having excellent luminous efficiency and durability can be obtained.

[0119] The organic compound according to this embodiment is more preferably used in the light-emitting layer of the organic light-emitting device under the following conditions: Note that a plurality of the following conditions may be satisfied simultaneously. (6) The light-emitting layer contains the organic compound represented by the general formula [1] in a concentration of 30% by mass or more and 95% by mass or less based on the entire light-emitting layer. (7) The light-emitting layer comprises an organic compound represented by the general formula [1] and a phosphorescent material having a ligand with a fused ring consisting of at least three rings. Each of the above conditions will be explained below.

[0120] (6) The light-emitting layer contains the organic compound represented by the general formula [1] in a concentration of 30% by mass or more and 99% by mass or less based on the entire light-emitting layer. When the organic compound according to this embodiment is used in the light-emitting layer, the concentration of the organic compound according to this embodiment in the entire light-emitting layer is preferably 30% by mass or more and 99% by mass or less. The organic compound according to this embodiment is highly amorphous, making it a suitable host material for the light-emitting layer. The concentration of the organic compound according to this embodiment in the entire light-emitting layer 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. Furthermore, since the organic compound according to this embodiment is highly amorphous and difficult to crystallize, it is a compound that exhibits excellent device life characteristics even when its concentration in the entire light-emitting layer is 99% by mass.

[0121] In order to improve the film properties of the light-emitting layer, the organic compound according to this embodiment may be used as an assist material. When used as an assist material, the concentration of the organic compound according to this embodiment relative to the entire light-emitting layer may be 30% by mass or more and 50% by mass or less.

[0122] (7) The light-emitting layer comprises an organic compound represented by the general formula [1] and a phosphorescent material having a ligand with a fused ring consisting of at least three rings. The organic compound according to this embodiment is a compound having fused rings consisting of three or more rings at both ends. Therefore, it is preferable that the phosphorescent material (guest material) used together with the organic compound according to this embodiment in the light-emitting layer has a structure in which the π-conjugation of the ligand is extended. More specifically, it is preferable that the phosphorescent material used together with the organic compound according to this embodiment has a fused ring consisting of three or more rings in the ligand structure.

[0123] This is because the guest material has a highly planar structure similar to that of the host material, and the highly planar portions of the guest material and the host material can approach each other through interaction. More specifically, the planar portions of the host material and the ligands of the organometallic complex (guest material) can easily approach each other. Therefore, it is expected that the intermolecular distance between the host material and the guest material will be shortened.

[0124] It is known that triplet energy used in phosphorescent devices undergoes energy transfer via the Dexter mechanism. Energy transfer via the Dexter mechanism occurs through contact between molecules. That is, by shortening the intermolecular distance between the host material and the guest material, energy transfer from the host material to the guest material is efficient.

[0125] As described above, by using a highly planar organometallic complex as a guest material, whose ligand structure has three or more fused rings, the intermolecular distance between the guest material and the host material, which is an organic compound represented by general formula [1], is shortened. This facilitates energy transfer from the host material to the guest material via the Dexter mechanism. As a result, an organic light-emitting device with high luminous efficiency can be provided.

[0126] Here, the highly planar fused ring structure consisting of three or more rings possessed by the ligand is preferably a triphenylene structure, a phenanthrene structure, a fluorene structure, a benzofluorene structure, a dibenzofuran structure, or a dibenzothiophene structure. 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 according to this embodiment can provide a light-emitting device with higher efficiency.

[0127] Specific examples of organometallic complexes according to this embodiment are shown below. However, the present invention is not limited to these. In the structural formulas below, two bonds between a bidentate ligand and an Ir atom may be represented by solid lines instead of arrows. In such cases, one bond may be a covalent bond and the other bond may be a coordinate bond.

[0128] [ka]

[0129] [ka]

[0130] [ka]

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] [ka]

[0135]

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[0136]

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[0137]

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[0138]

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[0139]

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[0140]

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[0141]

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[0142]

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[0143]

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[0144] Among the above organometallic complexes, the exemplary compounds belonging to the AA group (AA1 to AA30) and the BB group (BB1 to BB30) are compounds having at least a phenanthrene ring in the ligand of the Ir complex, and therefore, the fused ring is formed of an sp2 hybrid orbital, making these compounds particularly stable.

[0145] Among the above organometallic complexes, the exemplary compounds belonging to the CC group (CC1 to CC30) are compounds having at least a triphenylene ring in the ligand of the Ir complex, and therefore, the fused ring is formed of an sp2 hybrid orbital, making these compounds particularly stable.

[0146] Among the above organometallic complexes, the exemplary compounds belonging to the DD group (DD1 to DD56) are compounds having at least a dibenzofuran ring or a dibenzothiophene ring in the ligand of the Ir complex. Therefore, 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.

[0147] Among the above organometallic complexes, the exemplary compounds belonging to the EE group (EE1 to EE25), the FF group (FF1 to FF35), and the GG group (GG1 to GG35) are compounds having at least a benzofluorene ring in the ligand of the Ir complex. Therefore, these compounds further have a substituent at the 9-position of the fluorene. Therefore, since the substituent is in the direction perpendicular to the in-plane direction of the fluorene ring, it is possible to particularly prevent the fused rings from overlapping with each other. Therefore, these compounds have particularly excellent sublimation properties.

[0148] Among the above organometallic complexes, the exemplary compounds belonging to the HH group (HH1 to HH35) are compounds having at least a benzoisoquinoline ring in the ligand of the Ir complex. Therefore, 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.

[0149] Among the above organometallic complexes, the exemplary compounds belonging to Group II (II1 to II35) are compounds having at least a naphthoisoquinoline ring in the ligand of the Ir complex. Therefore, these compounds contain N atoms in the fused ring, and the unshared electron pairs and high electronegativity of these atoms can enhance charge transportability, making them particularly easy to adjust the carrier balance.

[0150] (Other compounds) Other examples of compounds that can be used in the organic light-emitting device of this embodiment are listed below.

[0151] As a hole injection / transport material suitable for use in the hole injection layer or hole transport layer, a material with high hole mobility is preferred so as to facilitate the injection of holes from the anode and transport the injected holes 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 the organic light-emitting device. Examples of low-molecular-weight and high-molecular-weight materials with hole injection / transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. Furthermore, the above-mentioned hole injection / transport materials are also suitable for use in the electron blocking layer.

[0152] Specific examples of compounds that can be used as hole injection and transport materials are shown below, but the present invention is not limited to these.

[0153] [ka]

[0154] Examples of luminescent materials mainly involved in luminescence function include organic compounds represented by general formula [1], as well as 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.

[0155] Specific examples of compounds that can be used as light-emitting materials are shown below, but the present invention is not limited to these.

[0156] [ka]

[0157] [ka]

[0158] Examples of the emission layer host or emission assist material contained in the emission layer include, in addition to the materials of the exemplary compounds A to D described above, aromatic hydrocarbon compounds or derivatives thereof, carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organic aluminum complexes such as tris(8-quinolinolato)aluminum, and organic beryllium complexes.

[0159] In particular, materials having a carbazole structure in the skeleton, materials having an azine ring in the skeleton, and materials having a xanthone structure in the skeleton are preferred as assist materials, because these materials have high electron donating and withdrawing properties, making it easy to adjust the HOMO and LUMO.

[0160] The organic compound represented by general formula [1] has a structure in which three or more fused rings are bonded to both ends of a linking group consisting of a phenylene chain, which results in a somewhat wide band gap. Therefore, materials with the above-mentioned skeleton that can adjust the HOMO and LUMO levels are particularly preferred as assist materials. When these assist materials are combined with the organic compound represented by general formula [1], a good carrier balance can be achieved.

[0161] Specific examples of compounds used as a host or assist material in the light-emitting layer together with the compound represented by general formula [1] or in a separate light-emitting layer are shown below, but the present invention is not limited to these.

[0162] 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.

[0163] [ka]

[0164] The electron transporting material can be arbitrarily selected from those capable of transporting electrons injected from the cathode to the light-emitting layer, and is selected in consideration of the balance with the hole mobility of the hole transporting material. Examples of materials having electron transporting 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 transporting materials are also suitable for use in hole-blocking layers.

[0165] Specific examples of compounds that can be used as electron transporting materials are shown below, but the present invention is not limited to these.

[0166] [ka]

[0167] The following describes the components other than the organic compound layer that make up the organic light-emitting device of this embodiment. The organic light-emitting device may be provided by forming a first electrode, an organic compound layer, and a second electrode on a substrate. One of the first electrode and the second electrode is an anode and the other is a cathode. A protective layer, a color filter, etc. may be provided on the second electrode. When a color filter is provided, a planarizing layer may be provided between the protective layer and the color filter. The planarizing layer may be made of acrylic resin, etc.

[0168] The substrate may be made of quartz, glass, silicon, resin, metal, or the like. Furthermore, a switching element such as a transistor and wiring may be provided on the substrate, and an insulating layer may be provided thereon. The insulating layer may be made of any material, as long as it can form a contact hole to ensure electrical continuity between the anode and the wiring and can ensure insulation from unconnected wiring. For example, resins such as polyimide, silicon oxide, silicon nitride, or the like may be used.

[0169] The anode material should preferably have a high work function. Examples include 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. These electrode materials can be used alone or in combination. The anode may be composed of a single layer or multiple layers. When used as a reflective electrode, materials such as chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates of these materials can be used. 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 can be used to form the anode.

[0170] 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 suppress silver aggregation. The alloy ratio is not critical as long as silver aggregation can be suppressed. For example, a 1:1 ratio is acceptable.

[0171] 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.

[0172] A protective layer may be provided after the cathode is formed. For example, by adhering glass provided with a moisture absorbent onto the cathode, it is possible to prevent water and other substances from penetrating the organic compound layer, thereby suppressing display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the cathode to prevent water and other substances from penetrating the organic compound layer. For example, after the cathode is formed, the device may be transported to another chamber without breaking the vacuum, and a silicon nitride film with a thickness of 2 μm may be formed by CVD to serve as a protective layer. A protective layer may also be provided using atomic layer deposition (ALD) after the film is formed by CVD.

[0173] Alternatively, a color filter may be provided for each pixel. For example, a color filter matching the size of the pixel 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 a protective layer such as silicon oxide using photolithography.

[0174] 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 this embodiment can be formed by the following methods. That is, to form the organic compound layers, dry processes such as vacuum deposition, ionization deposition, sputtering, and plasma can be used. Alternatively, instead of 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 (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.). Here, when a layer is formed by a vacuum deposition method or solution coating method, crystallization and the like are unlikely to occur and the layer has excellent stability over time. Furthermore, when a film is formed by a coating method, a film can be formed by combining it with an appropriate binder resin. Examples of binder resins include, but are not limited to, polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, and urea resin. The binder resin may be a homopolymer or a copolymer, and may be used singly or in combination of two or more kinds. If necessary, known additives such as plasticizers, antioxidants, and ultraviolet absorbers may be used in combination.

[0175] <Device using organic light-emitting element> 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.

[0176] The display device may be an image information processing device having an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., 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. In this case, the substrate may be a semiconductor substrate such as silicon, and the transistor may be a MOSFET formed on the substrate.

[0177] 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.

[0178] Next, the display device according to this embodiment will be described with reference to the drawings.

[0179] 1 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).

[0180] FIG. 1(a) shows an example of a pixel, which is a component of the display device according to this embodiment. The pixel includes subpixels 10. The subpixels 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 subpixels may be selectively transmitted or color-converted using a color filter or the like. Each subpixel includes a reflective electrode 2, which serves as a first electrode, on an interlayer insulating layer 1; an insulating layer 3 covering the edges of the reflective electrode 2; an organic compound layer 4 covering the first electrode and the insulating layer; a transparent electrode 5; a protective layer 6; and a color filter 7.

[0181] A transistor and a capacitor may be disposed below or inside the interlayer insulating layer 1. The transistor and the first electrode may be electrically connected via a contact hole or the like (not shown).

[0182] The insulating layer 3 is also called a bank or pixel separation film. It covers the edges of the first electrode and surrounds the first electrode. The part where the insulating layer is not provided contacts the organic compound layer 4 and becomes the light-emitting region.

[0183] 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 .

[0184] The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0185] The protective layer 6 reduces the penetration of moisture into the organic compound layer. Although the protective layer is illustrated as a single layer, it may be a multi-layer. Each layer may be an inorganic compound layer and an organic compound layer.

[0186] The color filters 7 are divided into 7R, 7G, and 7B depending on their colors. The color filters may be formed on a planarization film (not shown). A resin protective layer (not shown) may be provided on the color filters. The color filters may be formed on a protective layer 6. Alternatively, the color filters may be provided on an opposing substrate such as a glass substrate and then bonded thereto.

[0187] 1(b) includes an organic light-emitting element 26 and a TFT 18, which is 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 of the active element, a gate insulating film 14, and a semiconductor layer 15 are provided on top of the substrate 11.

[0188] The TFT 18 has a semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is provided on the top of the TFT 18. An anode 21 constituting an organic light-emitting element 26 and the source electrode 17 are connected via a contact hole 20.

[0189] The electrical connection 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 is not limited to the embodiment shown in Fig. 1(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.

[0190] 1(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 25 and a second protective layer 24 are provided on the cathode 23 to suppress deterioration of the organic light-emitting element.

[0191] In the display device 100 of FIG. 1(b), transistors are used as switching elements, but other switching elements such as MIM elements may be used instead.

[0192] The transistors used in the display device 100 of Fig. 1(b) are not limited to thin-film transistors having an active layer on an insulating surface of a substrate, but may also be transistors using a single-crystal silicon wafer. 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.

[0193] The transistors included in the display device 100 of Fig. 1(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 integrally formed.

[0194] 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.

[0195] 2 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.

[0196] The display device according to this embodiment may be used as a display unit of an imaging device having an optical unit with multiple 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 located within the viewfinder. The imaging device may be a digital camera or a digital video camera. The imaging device may also be referred to as a photoelectric conversion device.

[0197] 3A 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.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] The display device according to the present embodiment may be used as a display unit of an electronic device such as 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.

[0202] FIG. 3(b) is a schematic diagram showing an example of an electronic device according to this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit may be a biometric recognition unit that recognizes a fingerprint to perform operations such as unlocking. An electronic device having a communication unit can also be called a communication device.

[0203] FIG. 4 is a schematic diagram illustrating an example of a display device according to this embodiment. FIG. 4(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 include a light-emitting device according to this embodiment. The display device 1300 has a base 1303 that supports the frame 1301 and the display unit 1302. The base 1303 is not limited to the form shown in FIG. 4(a). The bottom side of the frame 1301 may also serve as the base. The frame 1301 and the display unit 1302 may be curved so that the display surface of the display unit 1302 is curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0204] FIG. 4(b) is a schematic diagram illustrating another example of a display device according to this embodiment. The display device 1310 in FIG. 4(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 a light-emitting device 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.

[0205] FIG. 5(a) is a schematic diagram illustrating an example of an illumination device according to this embodiment. The illumination device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical film 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 may be a filter that improves the color rendering of the light source. The light diffusion unit can effectively diffuse light from the light source, such as for illumination, and deliver the light over a wide area. The optical filter and the light diffusion unit may be provided on the light emission side of the illumination device. If necessary, a cover may be provided on the outermost part.

[0206] 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 for dimming them or a color tuning circuit for tuning the emitted color. The lighting device may have the organic light-emitting element of this embodiment and a power supply circuit connected to it. 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.

[0207] 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.

[0208] 5(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.

[0209] 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 EL element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but it is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0210] 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.

[0211] 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.

[0212] An application example of the display device of each of the above-described embodiments will be described with reference to Fig. 6. 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. An image capturing and displaying device used in such an application example includes an image capturing device capable of photoelectrically converting visible light and a displaying device capable of emitting visible light.

[0213] 6(a) illustrates glasses 1600 (smart glasses) according to one application example. An imaging device 1602 such as a CMOS sensor or SPAD is provided on the front side of a lens 1601 of the glasses 1600. Furthermore, a display device according to any of the above-described embodiments is provided on the back side of the lens 1601.

[0214] 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 according to each embodiment. 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.

[0215] FIG. 6(b) illustrates glasses 1610 (smart glasses) according to one application example. The glasses 1610 include a control device 1612, which is equipped with an imaging device equivalent to the imaging device 1602 and a display device. A lens 1611 includes an optical system for projecting light emitted from the imaging device and the display device within the control device 1612, and an image is projected onto the lens 1611. The control device 1612 functions as a power source for supplying power to the imaging device and the display device and controls the operation of the imaging device and the display device. The control device may also include a gaze detection unit for detecting the wearer's gaze. Infrared light may be used for gaze detection. The infrared light emitter emits infrared light toward the eyeball of a user gazing at a displayed image. An imaging unit with a light receiving element detects the reflected light of the emitted infrared light from the eyeball, thereby obtaining an image of the eyeball. A reduction unit for reducing light from the infrared light emitter to the display unit in a planar view reduces degradation of image quality.

[0216] The gaze of the user relative to the displayed image is detected from an image of the eyeball obtained by capturing infrared light. Any known method can be used for gaze detection using an image of the eyeball. One example is a gaze detection method based on the Purkinje image formed by reflection of irradiated light on the cornea.

[0217] More specifically, gaze detection processing is performed based on the pupil-corneal reflex method, which calculates a gaze vector representing the direction (rotation angle) of the eyeball based on the pupil image and Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0218] A display device according to an embodiment of the present invention may have an imaging device having a light receiving element, and may control the image displayed on the display device based on information about the user's line of sight from the imaging device.

[0219] 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.

[0220] 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.

[0221] 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.

[0222] 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.

[0223] FIG. 7 is a schematic diagram illustrating an example of an image forming apparatus according to this embodiment. 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, transport rollers 33, and a fixing unit 35. Light 29 is emitted from the exposure light source 28, and an electrostatic latent image is formed on the surface of the photoconductor 27. This 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 rollers 33 transport 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.

[0224] 8(a) and 8(b) 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 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(a) shows a configuration in which the light-emitting units 36 are arranged along the long axis direction of the photoconductor 27. FIG. 8(b) shows a different configuration from FIG. 8(a), 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(b) can also be described as a grid arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0225] 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]

[0226] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0227] Example 1 (Synthesis of Exemplary Compound A2)

[0228] [ka]

[0229] (1) Synthesis of compound m-3 The following reagents and solvents were placed in a 200 ml recovery flask.

[0230] Compound m-1: 4.0g (11.1mmol) Compound m-2: 1.7g (11.1mmol) Pd(PPh3)4: 0.13g Toluene: 40 ml Ethanol: 20ml 2M sodium carbonate solution: 20 ml The reaction solution was then heated under reflux under a nitrogen atmosphere and stirred for 6 hours. After the reaction was completed, water was added to separate the solution, and the solution was dissolved in chloroform. The solution was purified by column chromatography (chloroform:heptane) and recrystallized from toluene / heptane to obtain 3.0 g (yield: 78%) of compound m-3 as a white solid.

[0231] (2) Synthesis of compound m-5 The following reagents and solvents were placed in a 200 ml recovery flask.

[0232] Compound m-3: 2.5g (7.3mmol) Compound m-4: 1.8g (8.0mmol) Pd(PPh3)4: 0.08g Toluene: 25 ml Ethanol: 13 ml 2M sodium carbonate solution: 20 ml The reaction solution was then heated under reflux under a nitrogen atmosphere and stirred for 6 hours. After the reaction was completed, water was added to separate the solution, and the solution was dissolved in chloroform. The solution was purified by column chromatography (chloroform:heptane) and recrystallized from toluene / heptane to obtain 4.0 g (yield: 82%) of compound m-5 as a white solid.

[0233] (3) Synthesis of Compound A2 The following reagents and solvents were placed in a 200 ml recovery flask.

[0234] Compound m-5: 2.0g (4.5mmol) Compound m-6: 1.4g (5.0mmol) Pd(dba)2: 0.52g SPhos: 0.74g Potassium phosphate: 2.88g Toluene: 100 ml H2O: 10ml The reaction solution was then heated under reflux under a nitrogen stream and stirred for 6 hours. After the reaction was completed, water was added to separate the solution, and the solution was dissolved in chloroform. The solution was purified by column chromatography (chloroform:heptane) and then recrystallized from toluene / heptane to obtain 5.2 g (yield: 74%) of Example Compound A2 as a white solid.

[0235] The exemplary compound A25 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker).

[0236] [MALDI-TOF-MS] Measured value: m / z=632 Calculated value: C 90 H 32 =632 [Examples 2 to 20 (Synthesis of Exemplary Compounds)] As shown in Tables 6 and 7, the exemplary compounds of Examples 2 to 20 were synthesized in the same manner as in Example 1, except that raw materials m-4 and m-6 were changed from those of Example 1. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 1 are also shown.

[0237] [Table 6]

[0238] [Table 7]

[0239] [Comparative Examples 1 and 2 (Synthesis of Comparative Compounds)] As shown in Table 8, the comparative compounds of Comparative Examples 1 and 2 were synthesized in the same manner as in Example 1, except that the raw materials m-1, m-2, m-4, 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.

[0240] [Table 8]

[0241] [Example 21] 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.

[0242] First, an ITO film was formed on a glass substrate and then patterned as desired to form an ITO electrode (anode). The 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 steps. 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 9 on the ITO substrate. At this time, the electrode area of ​​the opposing electrode (metal electrode layer, cathode) was 3 mm2. 2 It was made to be like this.

[0243] [Table 9]

[0244] The device characteristics were measured and evaluated. The maximum emission wavelength of the light-emitting device was 522 nm, and the maximum external quantum efficiency (EQE) was 13%. Furthermore, at a current density of 100 mA / cm 2 A continuous driving test was carried out at 100°C, and the time (LT95) when the luminance degradation rate reached 5% was measured. The time (LT95) when the luminance degradation rate reached 5% in Comparative Example 1 was set to 1.0. In this case, the ratio of the time (LT95) when the luminance degradation rate reached 5% in this example was 1.4.

[0245] In this example, the measuring device was specifically a microcurrent meter 4140B manufactured by Hewlett-Packard Company to measure the current-voltage characteristics, and a BM7 manufactured by Topcon Corporation to measure the luminance.

[0246] [Examples 22 to 41, Comparative Examples 3 to 4] An organic light-emitting device was produced in the same manner as in Example 21, except that the materials forming each layer in Example 21 were appropriately changed to the compounds shown in Table 10. Layers not shown in Table 10 had the same configuration as in Example 21. 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 10, along with the results of Example 21.

[0247] [Table 10]

[0248] As shown in Table 10, the maximum external quantum efficiencies (EQE) of Comparative Examples 3 and 4 were 8% and 9%, respectively, whereas the maximum external quantum efficiencies of Examples 21 to 41 were 10% to 15%, indicating that the organic light-emitting devices of Examples 21 to 41 had higher luminous efficiency. This is thought to be because the compounds contained as hosts in the emitting layers of the organic light-emitting devices of Examples 21 to 41 had smaller ΔST than the organic compounds (Comparative Compounds 1-A and 1-B) contained as hosts in the emitting layers of the organic light-emitting devices of Comparative Examples 3 and 4. More specifically, the hosts of Examples 21 to 41 have a structure in which two fused rings are linked at the 4- and 3-positions of the 1,1':3',1"-terphenyl linking group, and therefore the S1 energy level is lowered while maintaining a high T1 energy level. Therefore, the T1 energy levels of the hosts of Examples 21 to 41 and those of Comparative Examples 3 and 4 are similar, and therefore the quantum efficiencies are thought to be similar. On the other hand, since the S1 energy levels of the hosts in Examples 21 to 41 were lower than the S1 energy levels of the hosts in Comparative Examples 3 to 4, Examples 21 to 41 had lower driving voltages than Comparative Examples 3 to 4. As a result, Examples 21 to 41 had higher maximum external quantum efficiencies (EQEs) than Comparative Examples 3 to 4.

[0249] Furthermore, the organic light-emitting devices of Examples 21 to 41 had a longer life than the organic light-emitting devices of Comparative Examples 3 and 4. This is thought to be because the compounds contained as hosts in the light-emitting layers of the organic light-emitting devices of Examples 21 to 41 were more amorphous and sublimable than the organic compounds (comparative compounds 1-A and 1-B) contained as hosts in the light-emitting layers of the organic light-emitting devices of Comparative Examples 3 and 4.

[0250] Furthermore, when an organic compound represented by the general formula [1] is used as a host and a phosphorescent material having a fused ring consisting of three or more rings as a ligand is used as a guest, a light-emitting device with particularly high efficiency and long life can be obtained. More specifically, when a phosphorescent light-emitting device having a structure selected from the group consisting of a triphenylene structure, a phenanthrene structure, a benzofluorene structure, a dibenzofuran structure, a dibenzothiophene structure, a benzoisoquinoline structure, and a naphthoisoquinoline structure is used as a guest, a light-emitting device with particularly high efficiency and long life can be obtained.

[0251] From the above, it was found that by using the compound represented by the general formula [1], it is possible to provide a device with high efficiency and excellent device durability characteristics.

[0252] [Example 42] 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 11 were successively formed.

[0253] [Table 11]

[0254] The device characteristics were measured and evaluated. The light-emitting device emitted green light and had a maximum external quantum efficiency (EQE) of 19%.

[0255] [Examples 43 to 67] An organic light-emitting device was produced in the same manner as in Example 42, except that the materials forming each layer in Example 42 were appropriately changed to the compounds shown in Table 12. Layers not listed in Table 12 had the same configuration as in Example 42. 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 12.

[0256] [Table 12]

[0257] As described above, by using the organic compound represented by general formula [1] as the host of the light-emitting layer and further using a material having a carbazole structure, an azine ring, or a xanthone structure as the assist material, an organic light-emitting element with high luminous efficiency was realized. [Explanation of symbols]

[0258] 1. Organic light-emitting device 11 Circuit Board 21 Anode 22 Organic compound layer 23 Cathode

Claims

1. An organic compound represented by the following general formula [1]: 【Chemistry 1】 (In the general formula [1], R １ and R ２ are each independently selected from the following Substituent Group A. However, when R 1 is a spirofluorene structure, R 2 is not a dibenzofuran structure or a dibenzothiophene structure. (Substituent group A) 【Chemistry 2】 【Transformation 3】 【Chemistry 4】 In the above-mentioned substituent group A, R １０１ ~R ５０６ are each independently selected from a hydrogen atom, a deuterium atom, an alkyl group, a substituted amino group, an aromatic hydrocarbon group, a heterocyclic group, or a cyano group. The alkyl group is selected from 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, and a cyclohexyl group. The substituted amino group is a diphenylamino group. The aromatic hydrocarbon group is selected from a phenyl group, a naphthyl group, a biphenyl group, a terphenyl group, a fluorenyl group, a phenanthryl group, a fluoranthenyl group, and a triphenylenyl group. The heterocyclic group is a pyridyl group, a pyrimidinyl group, or a triazinyl group.

2. In the general formula [1], R １ and R ２ 2. The organic compound according to claim 1, wherein at least one of the following is independently selected from the following substituent group B: ((Substituent group B) 【Transformation 5】 In the above-mentioned substituent group B, R ７０１ ~R ７４６ are each independently selected from a hydrogen atom, a deuterium atom, an alkyl group, a substituted amino group, an aromatic hydrocarbon group, a heterocyclic group, or a cyano group. The alkyl group is selected from 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, and a cyclohexyl group. The aromatic hydrocarbon group is selected from a phenyl group, a naphthyl group, a biphenyl group, a terphenyl group, a fluorenyl group, a phenanthryl group, a fluoranthenyl group, and a triphenylenyl group. The substituted amino group is a diphenylamino group. The heterocyclic group is a pyridyl group, a pyrimidinyl group, or a triazinyl group.

3. In the general formula [1], R １ and R ２ 2. The organic compound according to claim 1, wherein at least one of the following is independently selected from the following substituent group C: ((Substituent group C) 【Transformation 6】 In the above-mentioned substituent group C, R ８０１ ~R ８６８ are each independently selected from a hydrogen atom, a deuterium atom, and a phenyl group.

4. In the general formula [1], R １ and R ２ 2. The organic compound according to claim 1, wherein at least one of the following is independently selected from the following substituent group D: ((Substituent group D) 【Transformation 7】 In the above-mentioned substituent group D, R ９０１ ~R ９１８ are each independently selected from a hydrogen atom, a deuterium atom, and a phenyl group.

5. an anode and a cathode, an organic compound layer having at least a light-emitting layer, the organic compound layer being disposed between the anode and the cathode, The organic compound layer comprises the organic compound according to any one of claims 1 to 4. An organic light-emitting device.

6. The organic light-emitting element according to claim 5 , wherein the light-emitting layer contains the organic compound.

7. the light-emitting layer further comprises a phosphorescent material; 7. The organic light-emitting element according to claim 6, wherein the concentration of the organic compound in the light-emitting layer is 30% by mass or more and 99% by mass or less.

8. 8. The organic light-emitting element according to claim 7, wherein the phosphorescent material is an organometallic complex having at least three fused rings in the ligand.

9. 9. The organic light-emitting element according to claim 8, wherein the three or more fused rings have at least one structure selected from a triphenylene structure, a phenanthrene structure, a benzofluorene structure, a dibenzofuran structure, a dibenzothiophene structure, a benzoisoquinoline structure, and a naphthoisoquinoline structure.

10. 10. The organic light-emitting device according to claim 6, wherein the light-emitting layer further comprises a phosphorescent material and a third compound different from the organic compound and the phosphorescent material.

11. The organic light-emitting element according to claim 10 , wherein the third compound has a carbazole skeleton.

12. 12. The organic light-emitting device according to claim 10, wherein the third compound has an azine ring in its skeleton.

13. 13. The organic light-emitting device according to claim 10, wherein the third compound has a xanthone structure in its skeleton.

14. the light-emitting layer is a first light-emitting layer, a second light-emitting layer different from the first light-emitting layer is further provided between the first light-emitting layer and the anode or between the first light-emitting layer and the cathode; 14. The organic light-emitting element according to claim 5, wherein the second light-emitting layer emits light of a color different from that of the light emitted by the first light-emitting layer.

15. The organic light-emitting device according to claim 14, which emits white light.

16. having a plurality of pixels, A display device, wherein at least one of the plurality of pixels comprises the organic light-emitting element according to any one of claims 5 to 15, and an active element connected to the organic light-emitting element.

17. 17. The display device according to claim 16, further comprising a color filter.

18. 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; A photoelectric conversion device, wherein the display section comprises the organic light-emitting element according to any one of claims 5 to 15.

19. The device has a housing, a communication unit that communicates with the outside, and a display unit, 16. An electronic device, wherein the display unit comprises the organic light-emitting element according to claim 5.

20. An illumination device having a light source and a light diffusion unit or an optical filter, 16. A lighting device, wherein the light source comprises the organic light-emitting element according to claim 5.

21. A drone includes a body and a lighting fixture provided on the body, A moving body, wherein the lighting device comprises the organic light-emitting element according to any one of claims 5 to 15.

22. An exposure light source for an electrophotographic image forming apparatus, comprising the organic light-emitting element according to any one of claims 5 to 15.

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