Organic compound and organic light-emitting device

Abstract

To provide an organic compound excellent in luminous efficiency.SOLUTION: The organic compound is represented by general formula [1] or [2] in the figure, where X1 to X18 and X21 to X38 each represent a hydrogen atom, a halogen atom, an alkyl group, a heterocyclic group, or the like, provided that at least one of X1 to X8 and X21 to X28 is an amino group; Y represents oxygen, sulfur, a CR1CR2 group, or the like; and R1 to R2 each represent a hydrogen atom, an alkyl group, a heterocyclic group, or the like.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] An organic light-emitting element (hereinafter sometimes referred to as an "organic electroluminescence element" or "organic EL element") is an electronic element 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 element emits light. Recent progress in organic light-emitting devices has been remarkable, including low driving voltage, diverse emission wavelengths, high-speed response, and the possibility of making light-emitting devices thinner and lighter. In order to increase the efficiency of light-emitting elements, elements using efficient materials such as phosphorescent materials and delayed fluorescent materials can be mentioned. Patent Document 1 describes the following compound A-1. Patent Document 2 describes the following compound A-2.

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

[0004] [Patent Document 1] International Publication No. 2017 / 092476 [Patent Document 2] International Publication No. 2009 / 139580 Summary of the Invention [Problem to be solved by the invention]

[0005] When the compounds A-1 and A-2 described in Patent Documents 1 and 2 are used in the light-emitting layer of an organic light-emitting device, there is a problem with the light-emitting efficiency. The present invention has been made to solve the above problems, and an object of the present invention is to provide an organic compound and an organic light-emitting device having excellent luminous efficiency. Another object of the present invention is to provide an organic light-emitting device having excellent luminous efficiency and driving durability. [Means for solving the problem]

[0006] The organic compound of the present invention is characterized by being represented by the following general formula [1] or [2].

[0007] [ka] In formula [1] or [2], X 1 ~X 18 , X 21 ~X 38 represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, Trimethylsilyl group, triphenyl is independently selected from a silyl group and a cyano group. 1 ~X 8 At least one of the X 21 ~X 28 At least one of the X's is a substituted or unsubstituted amino group. The groups bonded to the nitrogen atoms of the substituted or unsubstituted amino groups may be bonded to each other to form a ring structure. The groups bonded to the nitrogen atoms of the substituted or unsubstituted amino groups may be bonded to each other to form a ring structure. 1 ~X 8 Either X 21 ~X 28 The group bonded to the nitrogen atom of a substituted or unsubstituted amino group may be bonded to the adjacent X through an oxygen or sulfur atom to form a ring. 1 ~X 8 Either X 21 ~X 28 may be bonded to any one of the groups to form a ring. The substituent that the alkyl group, the alkoxy group, the amino group, the aryl group, the heterocyclic group, the aryloxy group, and the heteroaryloxy group may have is an alkyl group, an aralkyl group, an aryl group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, a halogen atom, or a cyano group. Y is oxygen, sulfur, selenium, tellurium, C R 1 R 2 Represents one of the groups vinegar .R 1 ~R 2 represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, Trimethylsilyl group, triphenyl Each of the groups is independently selected from a silyl group and a cyano group. R 1 ~R 2 The substituent which the alkyl group, the alkoxy group, the amino group, the aryl group, the heterocyclic group, the aryloxy group, and the heteroaryloxy group may have is an alkyl group, an aralkyl group, an aryl group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, a halogen atom, or a cyano group. Effect of the Invention

[0008] The organic compound according to the present invention is less likely to cause molecular association and can reduce concentration quenching. Therefore, when the organic compound according to the present invention is used in an organic light-emitting device, an organic light-emitting device having excellent luminous efficiency and driving durability can be provided. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic cross-sectional view of an example of a display device using an organic light-emitting element according to one embodiment of the present invention. [Diagram 2] FIG. 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Diagram 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 an electronic 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. [Diagram 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 example of an automobile having a vehicle lamp according to an embodiment of the present invention. [Figure 6] 1 is a schematic diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Figure 7] 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 PREFERRED EMBODIMENTS

[0010] ≪Organic compounds≫ First, the organic compound according to the present embodiment will be described. The organic compound according to the present embodiment is represented by the following general formula [1] or [2].

[0011] [ka]

[0012] <X 1 ~X 18 , X 21 ~X 38 > X 1 ~X 18 , X 21 ~X 38 are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a silyl group, and a cyano group, provided that X 1 ~X 8 At least one of X 21 ~X 28 At least one of the X's is a substituted or unsubstituted amino group. The groups bonded to the nitrogen atoms of the substituted or unsubstituted amino groups may be bonded to each other to form a ring structure. The groups bonded to the nitrogen atoms of the substituted or unsubstituted amino groups may be bonded to each other to form a ring structure. 1 ~X 8 Either X 21 ~X 28The group bonded to the nitrogen atom of a substituted or unsubstituted amino group may be bonded to the adjacent X through an oxygen or sulfur atom to form a ring. 1 ~X 8 Either X 21 ~X 28 may be bonded to any one of the groups to form a ring.

[0013] Examples of halogen atoms include, but are not limited to, fluorine, chlorine, bromine, and iodine.

[0014] Examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a tertiary butyl group, a secondary butyl group, an octyl group, a cyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, etc. As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable.

[0015] Examples of the alkoxy group include, but are not limited to, a methoxy group, an ethoxy group, a propoxy group, a 2-ethyl-octyloxy group, a benzyloxy group, etc. The alkoxy group is preferably an alkoxy group having 1 to 10 carbon atoms.

[0016] Examples of the amino group include, but are not limited to, an N-methylamino group, an N-ethylamino group, an N,N-dimethylamino group, an N,N-diethylamino group, an N-methyl-N-ethylamino group, an N-benzylamino group, an N-methyl-N-benzylamino group, an N,N-dibenzylamino group, an anilino group, an N,N-diphenylamino group, an N,N-dinaphthylamino group, an N,N-difluorenylamino group, an N-phenyl-N-tolylamino group, an N,N-ditolylamino group, an N-methyl-N-phenylamino group, an N,N-dianisolylamino group, an N-mesityl-N-phenylamino group, an N,N-dimesitylamino group, an N-phenyl-N-(4-tert-butylphenyl)amino group, an N-phenyl-N-(4-trifluoromethylphenyl)amino group, an N-piperidyl group, a carbazolyl group, and an acridyl group.

[0017] Examples of the aryl group 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 triphenylenyl group, a pyrenyl group, an anthranyl group, a perylenyl group, a chrysenyl group, and a fluoranthenyl group. The aryl group is preferably an aromatic hydrocarbon group having 6 to 60 carbon atoms.

[0018] Examples of heterocyclic groups include, but are not limited to, pyridyl, pyrimidyl, pyrazyl, triazyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazolyl, acridinyl, and phenanthrolyl groups. Preferred heterocyclic groups are those having 3 to 60 carbon atoms.

[0019] Examples of aryloxy groups include, but are not limited to, phenoxy and naphthoxy groups.

[0020] Examples of heteroaryloxy groups include, but are not limited to, furanyloxy groups and thienyloxy groups.

[0021] Examples of the silyl group include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0022] Examples of the substituent that the above alkyl group, alkoxy group, amino group, aryl group, heterocyclic group, aryloxy group, and heteroaryloxy group may further have include alkyl groups such as methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, and tertiary butyl group; aralkyl groups such as benzyl group; aryl groups such as phenyl group and biphenyl group; heterocyclic groups such as pyridyl group and pyrrolyl group; amino groups such as dimethylamino group, diethylamino group, dibenzylamino group, diphenylamino group, and ditolylamino group; alkoxy groups such as methoxy group, ethoxy group, and propoxy group; aryloxy groups such as phenoxy group; halogen atoms such as fluorine, chlorine, bromine, and iodine; and cyano group, but are not limited to these.

[0023] X 2 , X 3 , X 6 , X 7 At least one of X 22 , X 23 , X 26 , X 27 At least one of X is preferably a substituted or unsubstituted amino group. 1 , X 4 , X 5 , X 8 At least one of X 21 , X 24 , X 25 , X 28 At least one of these is preferably a substituted or unsubstituted amino group.

[0024] <y> Y is oxygen, sulfur, selenium, tellurium, Cr 1 R 2 Represents one of the groups vinegar Preferably, Y is oxygen.

[0025] R 1 ~R 2 are each independently selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a silyl group, and a cyano group.

[0026] R 1 ~R 2 Specific examples of the alkyl group, alkoxy group, amino group, aromatic hydrocarbon group, heterocyclic group, aryloxy group, heteroaryloxy group, and silyl group represented by the formula: 1 ~X 18 , X 21 ~X 38 Examples of the substituents that may be further substituted by the alkyl group, alkoxy group, aromatic hydrocarbon group, heterocyclic group, aryloxy group, and heteroaryloxy group include, but are not limited to, X. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms. The alkoxy group is preferably an alkoxy group having 1 to 10 carbon atoms. The aromatic hydrocarbon group is preferably an aromatic hydrocarbon group having 6 to 60 carbon atoms. The heterocyclic group is preferably a heterocyclic group having 3 to 60 carbon atoms. Specific examples of the substituents that may be further substituted by the alkyl group, alkoxy group, amino group, aromatic hydrocarbon group, heterocyclic group, aryloxy group, and heteroaryloxy group include, but are not limited to, X. 1 ~X 18 , X 21 ~X 38 Examples of the above-mentioned examples include, but are not limited to, those described above.

[0027] Next, a method for synthesizing the organic compound according to the present embodiment will be described. The organic compound according to the present embodiment can be synthesized, for example, according to the reaction scheme shown below.

[0028] [ka]

[0029] Here, the above-mentioned substituent X can be appropriately changed, and Y can be replaced with oxygen, sulfur, selenium, tellurium, C R 1 R 2 By appropriately changing the groups, compounds represented by the general formulas [1] and [2] can be obtained. However, the synthesis method is not limited to these.

[0030] Next, since the organic compound according to this embodiment has the following characteristics, when used in an organic light-emitting device, it provides an organic light-emitting device with high light emission efficiency and excellent driving durability characteristics. The basic skeleton in this embodiment is X of the compound represented by the general formula [1] or [2]. 1 ~X 18 , X 21 ~X 38 are all hydrogen atoms and Y is CR 1 R 2 In the case of a group, R 1 ~R 2 is a skeleton in which all atoms are hydrogen atoms. (1) The spirofluorene has an electron-withdrawing carbonyl group on one fluorene ring and an electron-donating amino group on the other fluorene ring, resulting in S 1 and T 1 The energy gap is small. (2) By using Y as an electron-donating group, the band gap of the molecule becomes wider, and the molecule has a band gap more suitable for the light-emitting layer. (3) The spiro structure makes molecular association less likely to occur. (4) The spiro structure makes the bond at the quaternary carbon moiety less likely to be cleaved.

[0031] The features are explained below. (1) The spirofluorene has an electron-withdrawing carbonyl group on one fluorene ring and an electron-donating amino group on the other fluorene ring, resulting in S 1 and T 1 The energy gap is small.

[0032] In the compounds of this embodiment, as shown in Table 1, B-1 to B-3, the portion occupying the LUMO electron orbital distribution and the portion occupying the HOMO electron orbital distribution are separated via the spiro moiety of the spirofluorene. It can be seen that there are few portions occupying both the HOMO and LUMO. This means that the overlap integral is small, and the excited singlet state (S 1 ) and excited triplet state (T 1 ) will become smaller.

[0033] The above feature is an effect of having an electron-withdrawing carbonyl group on one fluorene ring of the spirofluorene and an electron-donating amino group on the other fluorene ring. It can be seen that, for structures without an amino group such as b-1 to b-4, the part occupying the LUMO electron orbital distribution and the part occupying the HOMO electron orbital distribution are not separated via the spiro part of the spirofluorene. Note that B-1 to B-3 are the exemplary compounds C-1, D-1, and E-1, respectively, which will be described later. Also, b-3 and b-4 are the compound A-2 (the comparative compound J-2, which will be described later) and the comparative compound J-1, respectively, in Patent Document 2.

[0034] [Table 1]

[0035] The above calculation results were visualized using molecular orbital calculations. The calculation method used for the molecular orbital calculations was the density functional theory (DFT), which is currently widely used. The functional was B3LYP, and the basis set was 6-31G. * It is also a smooth-flowing waveguide called Gaussian09(Gaussian09, RevisionC.01,MJFrisch,GWTrucks,HBSchlegel,GEScuse ria, MARobb,JRCheeseman,G.Scalmani,V.Barone,B.Mennucci,GAPetersson,H.Nakatsuji,M.Caricato,X.Li,HPHra tchian, AFIzmaylov, J. Bloino, G. Zheng, JLSonnenberg, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa, M. Ishi da,T.Nakajima,Y.Honda,O.Kitao,H.Nakai,T.Vreven,JAMontgomery,Jr.,JEPeralta,F.Ogliaro,M.Bearpark,JJHe yd, E. Brothers, KNKudin, VNS Taroverov, T. Keith, R. Kobayashi, J. Normand, K. Raghavachari, A. Rendell, JCBurant ,SSIyengar,J.Tomasi,M.Cossi,N.Rega,JMMillam,M.Klene,JEKnox,JBCross,V.Bakken,C.Adamo,J.Jaramillo,R.G omperts,REStratmann,O.Yazyev,AJAustin,R.Cammi,C.Pomelli,JWOchterski,RLMartin,K.Morokuma,VGZakrzews ki,GAVoth,P.Salvador,JJDannenberg,S.Dapprich,ADDaniels,O.Farkas,JBForesman,JVOrtiz,JCioslowski,and DJFox,Gaussian,Inc.,Wallingford CT,2010.)

[0036] This includes the B-1 exhibit B-3 and S 1 とT 1 Therefore, when the compound of this embodiment is used in the light-emitting layer of an organic light-emitting device, it provides a highly efficient light-emitting device. 1 and T 1 Since the excitons generated in a 1:3 ratio of singlet and triplet excitons are small, they can be used for delayed fluorescence emission, where triplet excitons that are normally thermally deactivated emit light from the singlet excited state. To convert triplet excitons to the singlet excited state, S 1 and T 1 The smaller the difference between these is, the smaller the energy barrier is, which is advantageous. The compound of the present embodiment is advantageous in this condition, and therefore provides a highly efficient light-emitting device.

[0037] On the other hand, the comparative compounds b-1 to b-4 do not have an amino group as a substituent, so 1 and T 1 The difference is large, resulting in a large energy barrier, which is disadvantageous for delayed fluorescence emission.

[0038] (2) By using Y as an electron-donating group, the band gap of the molecule becomes wider, and the molecule has a band gap more suitable for the light-emitting layer.

[0039] In the compound of this embodiment, when Y has a carbonyl group, which is an electron-withdrawing group, the basic skeleton has two carbonyl groups, so that the electron-withdrawing property is too strong and the band gap of the molecule becomes narrow. As a result, the emission wavelength becomes longer than that required for a light-emitting element. Specifically, b-5 in Table 1 is a compound having a carbonyl group, which is an electron-withdrawing group, in Y, but S 1 The value of 665 nm indicates that the absorption wavelength of the compound is already longer than the red emission region. R 1 R 2 In the case of a cyclic group, it has electron donating properties, so 1 It can be seen that the value of is 444 nm to 485 nm, which is a value suitable for emitting blue, green, and red light in the visible region. In other words, it has a band gap suitable for an emission layer in the visible light region.

[0040] (3) The spiro structure at the center of the molecule makes molecular association less likely to occur.

[0041] The compound of the present embodiment has a spiro structure, so that molecular association is unlikely to occur. The two fluorene rings are almost perpendicular to each other through the spiro structure, so the planarity of the molecule is low. In addition, since the spiro structure is located at the center of the molecule that separates the HOMO and LUMO, stacking of the molecules is unlikely to occur, and molecular association is unlikely to occur. On the other hand, in the case of a compound that does not have a spiro structure, such as b-4 in Table 1, the two phenyl groups bonded to the fluorene ring can rotate freely, so the planarity is high. Therefore, molecular association is likely to occur. In addition, even if the compound has a spiro structure, it is difficult to avoid stacking of the molecules even if the compound has a spiro structure in a part that is not involved in the HOMO and LUMO or in the end of the molecule.

[0042] The above effect is that when the compound of this embodiment is used in an organic layer of an organic light-emitting element, it is difficult to crystallize, forms a stable amorphous film, and provides an organic light-emitting element that is highly durable and does not crystallize even when driven for a long period of time.

[0043] Furthermore, when the compound of this embodiment is used in the light-emitting layer of an organic light-emitting device, molecular association is unlikely to occur, and therefore concentration quenching is unlikely to occur, resulting in an organic light-emitting device with high light-emitting efficiency.

[0044] The above effect also has the effect of improving sublimability. The improvement of sublimability makes it possible to highly purify materials by sublimation purification and to fabricate organic light-emitting devices by vapor deposition. This makes it possible to reduce impurities contained in the organic light-emitting devices, and to prevent the deterioration of luminous efficiency and driving durability caused by impurities.

[0045] (4) The spiro structure makes the bond at the quaternary carbon moiety less likely to be cleaved.

[0046] In the compound of this embodiment, the quaternary carbon in the dotted line part in the chemical formula below has a spiro structure, so that even if it is cleaved, the cleaved phenyl group is bonded to the main structure, so it is easy to return to the original structure. In the case of a non-spiro structure such as compound A-1 in Patent Document 1, when it is cleaved, the cleaved phenyl group is not bonded to the main structure, so it is difficult to return to the original structure. Therefore, since it is easy to cleave and the structure is easily changed, the durability of the element is deteriorated.

[0047] [ka]

[0048] Furthermore, the compound of this embodiment preferably has the following characteristics (5) and (6) regarding the position of the amino group.

[0049] (5)X 2 , X 3 , X 6 , X 7 At least one of X 22 , X 23 , X 26 , X 27 When at least one of the groups is an amino group, S 1 and T 1 This further reduces the energy gap, which is more preferable.

[0050] As shown in Table 2, in this case, a device with even higher light emission efficiency is provided. 2 , X 3 , X 6 , X 7 At least one of X 22 , X 23 , X 26 , X 27 When at least one of the groups is an amino group, S 1 and T 1 The energy gap at the substitution position is smaller than that at other substitution positions, which is more preferable. In this case, the efficiency of the device is further increased, which is more preferable. Note that B-2 and B-4 are Exemplary Compounds D-1 and D-5, which will be described later, respectively.

[0051] [Table 2]

[0052] (6)X 1 , X 4 , X 5 , X 8 At least one of X 21 , X 24 , X 25 , X 28 When at least one of the groups is an amino group, stacking of the molecules is less likely to occur, and molecular association is therefore less likely to occur, which is preferable.

[0053] X 1 , X 4 , X 5 , X 8 At least one of X 21 , X 24 , X 25 , X 28 When at least one of the groups is an amino group, the amino group has a steric hindrance to the basic skeleton, which causes some distortion of the molecule and disrupts the planarity of the molecule. Therefore, stacking of the molecules is unlikely to occur, and molecular association is unlikely to occur, which is preferable.

[0054] In this case, when the compound of the present embodiment is used in an organic layer of an organic light-emitting element, it is preferable because it forms a stable amorphous film that is difficult to crystallize and does not crystallize even when driven for a long period of time, thereby obtaining an organic light-emitting element that is excellent in durability.

[0055] Furthermore, when the compound of this embodiment is used in the light-emitting layer of an organic light-emitting device, molecular association is unlikely to occur, and concentration quenching is unlikely to occur, which is preferable for obtaining an organic light-emitting device with high light emission efficiency.

[0056] Furthermore, it also has the effect of improving sublimability. The improvement of sublimability makes it possible to highly purify materials by sublimation purification and to prepare organic light-emitting devices by vapor deposition. This is preferable because it reduces impurities contained in the organic light-emitting device and prevents the deterioration of luminous efficiency and driving durability caused by impurities.

[0057] Furthermore, the compound of this embodiment is preferably used in an emitting layer in an organic light-emitting device, and in that case, it has the following characteristics. (7) By mixing the compound of this embodiment with a host material in the light-emitting layer, the compound of this embodiment is more likely to cause exciton recombination, providing a highly efficient light-emitting device. (8) The compound of this embodiment is mixed with a host material in a light-emitting layer, and further contains a light-emitting material, thereby providing a light-emitting device with high efficiency and high color purity. (9) When the light emitting material is a hydrocarbon compound, a light emitting element having high efficiency and excellent durability can be provided.

[0058] The features are explained below. (7) By mixing the compound of this embodiment with a host material in the light-emitting layer, the compound of this embodiment is more likely to cause exciton recombination, providing a highly efficient light-emitting device.

[0059] The compound of this embodiment has an electron-withdrawing carbonyl group and an electron-donating amino group. Therefore, by mixing the compound of this embodiment with a host material in the light-emitting layer of an organic light-emitting device, the LUMO of the compound of this embodiment is at a lower level (farther from the vacuum level) than the host material, and the HOMO of the compound of this embodiment is at a higher level (closer to the vacuum level) than the host material. Therefore, electrons and holes supplied from the transport layer in the light-emitting layer are trapped by the compound of this embodiment, and exciton recombination takes place. As described in the above characteristic (1), the compound of this embodiment has the S 1 and T 1 Since the difference between the HOMO and LUMO energies is small, delayed fluorescent emission is efficiently generated in the light-emitting layer, and more triplet excitons can be used for emission. This effect is particularly pronounced when the host material is a hydrocarbon compound, since the energy difference between the HOMO and LUMO energies of the host and the compound of this embodiment becomes large, making it easier to trap electrons and holes. A hydrocarbon compound is a compound that is composed only of carbon and hydrogen in its molecule.

[0060] Furthermore, as described in the above feature (3), the compound of this embodiment is unlikely to cause molecular association, and therefore is unlikely to cause concentration quenching in the host material. This effect leads to the prevention of quenching due to the interaction between excitons when the compound of this embodiment is in an excited state, and is effective in efficiently generating delayed fluorescence emission in the light-emitting layer.

[0061] (8) The compound of this embodiment is mixed with a host material in a light-emitting layer, and further contains a light-emitting material, thereby providing a light-emitting device with high efficiency and high color purity.

[0062] A light-emitting device with higher efficiency and higher color purity can be provided by using the compound of this embodiment in the light-emitting layer and further doping a light-emitting material with high luminescence quantum yield or a light-emitting material having a spectrum suitable for high color purity in the emission spectrum, which is used as a light-emitting material. In this case, the compound of this embodiment needs to be configured in a concentration in the light-emitting layer that allows electrons and holes to be preferentially trapped in order to facilitate exciton recombination, and the concentration of the organic compound of this embodiment is preferably 0.1% by mass or more and 45% by mass or less, and more preferably 1% by mass or more and 30% by mass or less, based on the entire light-emitting layer.

[0063] On the other hand, since a lower doping concentration of the luminescent material is less susceptible to concentration quenching and changes in the emission spectrum due to interactions between molecules, it is preferable to dope a luminescent material in the luminescent layer other than the compound of this embodiment. The concentration of the luminescent material is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 1% by mass or more and 15% by mass or less, based on the entire luminescent layer. As a result, a light-emitting element with high efficiency and high color purity can be provided.

[0064] (9) When the light emitting material is a hydrocarbon compound, a light emitting element having high efficiency and excellent durability can be provided.

[0065] Since the compound of this embodiment has a carbonyl group with strong electron-withdrawing properties, the doped light-emitting material described in the above feature (8) is preferably a light-emitting material that does not have an amino group, which is an electron-donating group, and is preferably a hydrocarbon compound. The reason is that a light-emitting material having an amino group may interact with the carbonyl group of the compound of this embodiment in the light-emitting layer, resulting in a decrease in light-emitting efficiency due to exciplex formation, or a change in the light-emitting spectrum of the light-emitting material, which may deteriorate the color purity of the light-emitting element.

[0066] Furthermore, luminescent materials with amino groups have a low ionization potential and are therefore easily oxidized, resulting in poor device durability. For this reason, luminescent materials are preferably hydrocarbon compounds, and more preferably condensed polycyclic compounds with a five-membered ring. This is because their higher ionization potential makes them less susceptible to oxidation. A hydrocarbon compound is a compound that is composed only of carbon and hydrogen in its molecule.

[0067] As described above, by mixing the compound of this embodiment with a host material in the light-emitting layer, an organic light-emitting element with high light emission efficiency can be obtained. In this case, the light-emitting material may be the compound of this embodiment, or a light-emitting material may be further mixed and the compound of this embodiment may function as an assist material. By using a light-emitting material with good color purity, an organic light-emitting element with high efficiency and high color purity can be obtained. Furthermore, when the host material is a hydrocarbon compound, the compound of this embodiment is preferred because it easily traps electrons and holes, which greatly increases the effect of increasing efficiency.

[0068] Specific examples of the organic compound according to this embodiment are shown below, but the present invention is not limited to these.

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] Group C is a compound represented by the general formula [1] in which Y is oxygen, and group D is a compound represented by the general formula [2] in which Y is oxygen. By using oxygen as Y, chemical reactions such as oxidation are unlikely to occur, and chemically stable compounds are provided.

[0077] Group E is a compound represented by the general formula [1] in which Y is sulfur, and group F is a compound represented by the general formula [2] in which Y is sulfur. Since Y is sulfur, the radius of the element is larger than that of oxygen, and the formation vinegar The six-membered ring becomes distorted, and the planarity of the molecule is lost. This makes it even more difficult for concentration quenching to occur.

[0078] Group G includes compounds represented by the general formula [1] or [2] in which Y is selenium or tellurium. When Y is selenium or tellurium, it has a d orbital and is a metallic element, so the electron mobility is high.

[0079] Group H includes compounds represented by the general formula [1] or [2] in which Y is C R 1 R 2 R 1 and R 2 The introduction of 1 and R 2 The introduction of groups other than hydrogen into the compound breaks down the planarity of the molecule, making it even less susceptible to concentration quenching.

[0080] <Organic light-emitting element> Next, the organic light-emitting device of this embodiment will be described.

[0081] The organic light-emitting element of this embodiment has at least a pair of electrodes, an anode and a cathode, and an organic compound layer disposed between these electrodes. In the organic light-emitting element of this embodiment, the organic compound layer may be a single layer or a laminate consisting of multiple layers as long as it has a light-emitting layer. Here, when the organic compound layer is a laminate consisting of multiple layers, the organic compound layer may have a hole injection layer, a hole transport layer, an electron blocking layer, a hole exciton blocking layer, an electron transport layer, an electron injection layer, etc. in addition to the light-emitting layer. The light-emitting layer may be a single layer or a laminate consisting of multiple layers.

[0082] In the organic light-emitting device of the present embodiment, at least one layer of the organic compound layer contains the organic compound according to the present embodiment. Specifically, the organic compound according to the present embodiment is contained in any of the above-mentioned light-emitting layer, hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole exciton blocking layer, electron transport layer, electron injection layer, etc. The organic compound according to the present embodiment is preferably contained in the light-emitting layer. The light-emitting layer can emit green or red light, but the emission color is not limited thereto.

[0083] In the organic light-emitting device of this embodiment, when the organic compound according to this embodiment is contained in the light-emitting layer, the light-emitting layer may be a layer consisting of only the organic compound according to this embodiment, or may be a layer consisting of the organic compound according to this embodiment and other compounds. Here, when the light-emitting layer is a layer consisting of the organic compound according to this embodiment and other compounds, the organic compound according to this embodiment may be used as a host of the light-emitting layer or as a guest. It may also be used as an assist material that can be contained in the light-emitting layer. Here, the host is a compound having the largest mass ratio among the compounds constituting the light-emitting layer. The guest is a compound having a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and is a compound that is responsible for the main emission of light. The assist material is a compound having a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and assists the emission of the guest.

[0084] When the organic compound according to the present embodiment is used as a guest in the light-emitting layer, the concentration of the guest is preferably 0.01% by mass to 20% by mass, and more preferably 1% by mass to 15% by mass, based on the entire light-emitting layer. When the organic compound according to the present embodiment is used as an assist material in the light-emitting layer, the concentration of the assist material is preferably 0.1% by mass to 45% by mass, and more preferably 1% by mass to 30% by mass, based on the entire light-emitting layer.

[0085] In addition, when the organic compound according to this embodiment is used as a guest in the light-emitting layer, it is preferable to use a material having a higher LUMO than the organic compound according to this embodiment (a material having a LUMO closer to the vacuum level) as a host. This is because the organic compound according to this embodiment tends to have a low LUMO, and by using a material having a higher LUMO than the organic compound according to this embodiment as a host, the organic compound according to this embodiment can receive more electrons supplied to the host in the light-emitting layer.

[0086] In addition, when the organic compound according to this embodiment is used as an assist material for the light-emitting layer, it is preferable to use a material having a higher LUMO than the organic compound according to this embodiment (a material having a LUMO closer to the vacuum level) as a guest. This is because the organic compound according to this embodiment tends to have a low LUMO. Therefore, by using a material having a higher LUMO than the organic compound according to this embodiment as the light-emitting material (guest), the organic compound according to this embodiment receives more electrons supplied to the host of the light-emitting layer, and the assist material is responsible for exciton recombination. As a result, it becomes possible to efficiently transfer energy to the light-emitting material (guest).

[0087] The present inventors have conducted various studies and found that when the organic compound according to this embodiment is used as a host, guest, or assist material of the light-emitting layer, particularly as a guest of the light-emitting layer, an element exhibiting high efficiency and high luminance light output and extremely high durability can be obtained. Furthermore, when the organic compound is used as an assist material of the light-emitting layer, an element exhibiting high efficiency and high luminance light output and extremely high durability can be obtained. The light-emitting layer may be a single layer or multiple layers, and may contain multiple light-emitting materials. The multiple layers may be a state in which the light-emitting layer and another light-emitting layer are laminated, or an intermediate layer may be laminated between multiple light-emitting layers. In addition, a tandem element or a stack element may be used. In these cases, the emission color of the organic light-emitting element is not limited to a single color. More specifically, it may be white or may be an intermediate color. In addition, the film is formed by deposition or coating. Details of this will be described in detail in the examples below.

[0088] The organic compound according to the present embodiment can be used as a constituent material of an organic compound layer other than the light-emitting layer constituting the organic light-emitting device of the present embodiment. Specifically, the organic compound can be used as a constituent material of an electron transport layer, an electron injection layer, a hole transport layer, a hole injection layer, a hole blocking layer, etc.

[0089] In addition to the organic compound according to the present embodiment, conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host compounds, light-emitting compounds, electron-injecting or electron-transporting compounds, etc. may be used together as necessary. Examples of these compounds are given below.

[0090] As the hole injection transport material, a material having high hole mobility is preferable so that the injection of holes from the anode can be easily performed and the injected holes can be transported to the light emitting layer. In addition, a material having a high glass transition temperature is preferable so as to reduce deterioration of the film quality such as crystallization in the organic light emitting device. Examples of low molecular weight and high molecular weight materials having hole injection transport performance include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. Furthermore, the above hole injection transport material is also preferably used in the electron blocking layer. Specific examples of compounds used as the hole injection transport material are shown below, but of course, the present invention is not limited to these.

[0091] [ka]

[0092] Among the hole transport materials, HT16 to HT18 can reduce the driving voltage by using them in a layer in contact with the anode. HT16 is widely used in organic light-emitting elements. HT2, HT3, HT4, HT5, HT6, HT10, and HT12 may be used in an organic compound layer adjacent to HT16. Also, multiple materials may be used in one organic compound layer.

[0093] Examples of luminescent materials mainly involved in luminescence function include organic compounds represented by the general formulas [1] and [2], 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. Specific examples of compounds used as luminescent materials are shown below, but are of course not limited to these.

[0094] [ka]

[0095] [ka]

[0096] When the luminescent material is a hydrocarbon compound, it is preferable because it prevents a decrease in luminous efficiency due to exciplex formation and a deterioration in color purity due to a change in the emission spectrum of the luminescent material. A hydrocarbon compound is a compound composed only of carbon and hydrogen, and corresponds to BD7, BD8, GD5 to GD9, and RD1. When the luminescent material is a condensed polycyclic ring containing a five-membered ring, it is even more preferable because it has a high ionization potential, is less likely to be oxidized, and provides an element with a long durable life. Corresponding examples are BD7, BD8, GD5 to GD9, and RD1.

[0097] Examples of the light-emitting layer host or light-emitting assist material contained in the light-emitting layer include aromatic hydrocarbon compounds or derivatives thereof, as well as carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organic aluminum complexes such as tris(8-quinolinolato)aluminum, organic beryllium complexes, etc. Specific examples of compounds used as the light-emitting layer host or light-emitting assist material contained in the light-emitting layer are shown below, but the present invention is not limited to these.

[0098] [ka]

[0099] When the host material is a hydrocarbon compound, the compound of this embodiment is preferable because it easily traps electrons and holes, and therefore has a large effect of improving efficiency. The hydrocarbon compound is a compound composed only of carbon and hydrogen, and corresponds to EM1 to EM12 and EM16 to EM27.

[0100] 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, organic aluminum complexes, and condensed ring compounds (e.g., fluorene derivatives, naphthalene derivatives, chrysene derivatives, anthracene derivatives, etc.). Furthermore, the above electron transporting materials are also preferably used in the hole blocking layer. Specific examples of compounds used as electron transporting materials are shown below, but are of course not limited to these.

[0101] [ka]

[0102] The electron injection material can be selected from those that can easily inject electrons from the cathode, taking into consideration the balance with hole injection properties. Organic compounds include n-type dopants and reducing dopants. Examples include compounds containing alkali metals such as lithium fluoride, lithium complexes such as lithium quinolinol, benzimidazolidene derivatives, imidazolidene derivatives, fulvalene derivatives, and acridine derivatives.

[0103] <Configuration of organic light-emitting element> The organic light-emitting element is provided by forming an anode, an organic compound layer, and a cathode on a substrate. A protective layer, a color filter, and the like may be provided on the cathode. 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 or the like.

[0104] [substrate] Examples of the substrate include quartz, glass, silicon wafer, resin, and metal. In addition, a switching element such as a transistor and wiring may be provided on the substrate, and an insulating layer may be provided thereon. As the insulating layer, any material can be used as long as it can form a contact hole to ensure electrical continuity between the anode and the wiring and can ensure insulation from wiring that is not connected. For example, resin such as polyimide, silicon oxide, silicon nitride, etc. can be used.

[0105] [electrode] A pair of electrodes can be used. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0106] The material constituting the anode should have as large a work function as possible. For example, metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, tungsten, etc., mixtures containing these metals, alloys combining these metals, metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide can be used. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0107] These electrode materials may be used alone or in combination of two or more kinds. The anode may be composed of one layer or multiple layers.

[0108] When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or an alloy or laminate of these can be used. When used as a transparent electrode, a transparent conductive layer of oxide such as indium tin oxide (ITO) or indium zinc oxide can be used, but is not limited to these. Photolithography technology can be used to form the electrode.

[0109] On the other hand, the material for the cathode should have a small work function. Examples of the material include alkali metals such as lithium, alkaline earth metals such as calcium, aluminum, titanium, manganese, silver, lead, chromium, and other metals or mixtures containing these metals. Alternatively, alloys combining these metals can be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, zinc-silver, and the like can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials may be used alone or in combination of two or more types. The cathode may have a single layer structure or a multi-layer structure. Among these, it is preferable to use silver, and it is even more preferable to use a silver alloy to reduce the aggregation of silver. As long as the aggregation of silver can be reduced, the ratio of the alloy is not important. For example, it may be 1:1.

[0110] 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 it is more preferable to use a direct current or alternating current sputtering method, etc., since the film coverage is good and the resistance can be easily reduced.

[0111] [Protective layer] A protective layer may be provided on the cathode. For example, by bonding glass provided with a moisture absorbent on the cathode, it is possible to suppress the intrusion of water and the like into the organic compound layer and suppress the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the cathode to suppress the intrusion of water and the like into 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 having a thickness of 2 μm may be formed by the CVD method to serve as a protective layer. A protective layer may be provided using the atomic deposition method (ALD method) after the film formation by the CVD method.

[0112] [Color Filter] A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on another substrate and then bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer described above using a photolithography technique. The color filter may be made of a polymer.

[0113] [Planarization layer] A planarizing layer may be provided between the color filter and the protective layer. The planarizing layer may be made of an organic compound, and may be a low molecular weight or a high molecular weight compound, but is preferably a high molecular weight compound.

[0114] The planarization layer may be provided above and below the color filter, and may be made of the same or different materials.Specific examples of the materials include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0115] [Opposite substrate] The flattening layer may have a counter substrate on it. The counter substrate is called a counter substrate because it is provided at a position corresponding to the aforementioned substrate. The material of the counter substrate may be the same as that of the aforementioned substrate.

[0116] [Organic layer] The organic compound layers (hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) constituting the organic light emitting device according to one embodiment of the present invention are formed by the method shown below.

[0117] The organic compound layer constituting the organic light-emitting device according to one embodiment of the present invention can be formed by dry processes such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Alternatively, instead of the dry process, a wet process can be used in which a layer is formed by dissolving the compound in an appropriate solvent and applying a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.).

[0118] Here, when the layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When the layer is formed by a coating method, the layer can be formed by combining with a suitable binder resin.

[0119] Examples of the binder resin include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0120] These binder resins may be used alone or in combination as homopolymers or copolymers, and may further include known additives such as plasticizers, antioxidants, and ultraviolet absorbers, if necessary.

[0121] <Applications of the organic light-emitting device according to this embodiment> The organic light-emitting device according to an embodiment of the present invention 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, a light-emitting device having a white light source and a color filter, etc.

[0122] 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, and at least one of the plurality of pixels may have the organic light-emitting element of this embodiment and a transistor connected to the organic light-emitting element.

[0123] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of the touch panel function may be an infrared type, a capacitance type, a resistive film type, or an electromagnetic induction type, and is not particularly limited. The display device may be used in the display unit of a multifunction printer.

[0124] Next, the display device according to the present embodiment will be described with reference to the drawings. Fig. 1 is a schematic cross-sectional view showing an example of a display device having an organic light-emitting element and a TFT element connected to the organic light-emitting element. The TFT element is an example of an active element.

[0125] 1 includes a substrate 11 such as glass and a moisture-proof film 12 for protecting a TFT element or an organic compound layer provided thereon. Reference numeral 13 denotes a metal gate electrode. Reference numeral 14 denotes a gate insulating film, and reference numeral 15 denotes a semiconductor layer.

[0126] The TFT element 18 has a semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is provided on the upper part of the TFT element 18. An anode 21 constituting an organic light emitting element 26 and the source electrode 17 are connected via a contact hole 20.

[0127] The method of 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 element 18 is not limited to the embodiment shown in Fig. 1. 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 element 18.

[0128] 1, the organic compound layer 22 is illustrated as a single layer, but the organic compound layer 22 may be a multi-layer structure. A first protective layer 24 and a second protective layer 25 are provided on the cathode 23 to reduce deterioration of the organic light-emitting element 26.

[0129] In the display device 10 of FIG. 1, transistors are used as switching elements, but MIM elements may be used instead as switching elements.

[0130] The transistors used in the display device 10 of Fig. 1 are not limited to transistors using single crystal silicon wafers, but may be thin film transistors having an active layer on an insulating surface of a substrate. Examples of the active layer include single crystal silicon, amorphous silicon, non-single crystal silicon such as microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin film transistors are also called TFT elements.

[0131] The transistors included in the display device 10 of Fig. 1 may be formed in a substrate such as a Si substrate. Here, "formed in a substrate" means that the substrate itself such as a Si substrate is processed to produce the transistors. In other words, having a transistor in a substrate can be seen as the substrate and the transistor being integrally formed.

[0132] 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, and by providing the organic light-emitting element on a plurality of surfaces, an image can be displayed based on the emission brightness of each element. The switching element according to this embodiment is not limited to a TFT, and may be a transistor formed of low-temperature polysilicon or an active matrix driver formed on a substrate such as a Si substrate. On the substrate may also be within the substrate. Whether to provide a transistor within the substrate or to use a TFT is selected according to the size of the display unit. For example, if the size is about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

[0133] 2 is a schematic diagram showing an example of a display device according to the present embodiment. The display device 1000 may have a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. Flexible printed circuits FPC1002 and 1004 are connected to the touch panel 1003 and the display panel 1005. A transistor is 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 if the display device is a portable device.

[0134] The display device according to the present embodiment may be used as a display unit of a photoelectric conversion device such as an imaging device having an optical unit with a plurality of lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the imaging device or a display unit disposed within a viewfinder. The imaging device may be a digital camera or a digital video camera.

[0135] 3(a) is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may have a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may have 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 moving speed of the subject, the possibility that the subject will be blocked by an obstruction, and the like.

[0136] Since the timing suitable for imaging is 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 an organic light-emitting element can be used more preferably than a liquid crystal display device, which requires a high display speed.

[0137] The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses, and forms an image on an imaging element housed in a housing 1104. The focal points of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically.

[0138] The display device according to this embodiment may have color filters having red, green, and blue colors, the red, green, and blue colors being arranged in a delta arrangement.

[0139] 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.

[0140] 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 unlocking or the like. An electronic device having a communication unit may be called a communication device.

[0141] FIG. 4 is a schematic diagram showing an example of a display device according to the present embodiment. FIG. 4(a) shows 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 light-emitting device according to the present embodiment may be used for the display unit 1302. The display device 1300 has the frame 1301 and a base 1303 that supports the display unit 1302. The base 1303 is not limited to the form shown in FIG. 4(a). The lower side of the frame 1301 may also serve as the base. The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0142] FIG. 4(b) is a schematic diagram showing another example of the display device according to the present 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 have the light-emitting device according to the present embodiment. The first display unit 1311 and the second display unit 1312 may be one display unit without a joint. The first display unit 1311 and the second display unit 1312 can be separated at the bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first and second display units may display one image.

[0143] FIG. 5(a) is a schematic diagram showing an example of a lighting device according to the present embodiment. The lighting device 1400 may have a housing 1401, a light source 1402, a circuit board 1403, an optical filter 1404 that transmits light emitted by the light source 1402, and a light diffusion unit 1405. The light source 1402 may have an organic light-emitting element according to the present embodiment. The optical filter 1404 may be a filter that improves the color rendering of the light source. The light diffusion unit 1405 can effectively diffuse the light of the light source, such as for lighting up, and deliver the light over a wide range. The optical filter 1404 and the light diffusion unit 1405 may be provided on the light emission side of the lighting. If necessary, a cover may be provided on the outermost part.

[0144] The lighting device is, for example, a device that illuminates a room. The lighting device may emit white light, natural white light, or any other color from blue to red. It may have a dimming circuit that adjusts the light intensity. The lighting device may have the organic light-emitting element of this embodiment and a power supply circuit connected thereto. The power supply circuit is a circuit that converts AC voltage into DC voltage. Moreover, white has a color temperature of 4200K, and natural white has a color temperature of 5000K. The lighting device may have a color filter.

[0145] The lighting device according to the present embodiment may also include a heat dissipation section that dissipates heat from within the device to the outside, and examples of the heat dissipation section include metals with high specific heat, liquid silicon, and the like.

[0146] 5B 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 a lamp. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking or the like is performed.

[0147] The tail lamp 1501 may have an organic light-emitting element according to this embodiment. The tail lamp 1501 may have a protective member for protecting the organic light-emitting element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0148] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window 1502 may be a transparent display unless it is 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 members.

[0149] The moving body according to the present embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lamp provided on the body. The lamp may emit light to indicate the position of the body. The lamp has the organic light-emitting element according to the present embodiment.

[0150] FIG. 6 is a schematic diagram showing an example of an image forming apparatus according to the present 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, a transport roller 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. The exposure light source 28 includes an organic light-emitting element according to the present embodiment. The developing unit 31 includes a toner and the like. The charging unit 30 charges the photoconductor 27. The transfer unit 32 transfers the developed image to a recording medium 34. The transport roller 33 transports the recording medium 34. The recording medium 34 is, for example, paper. The fixing unit 35 fixes the image formed on the recording medium 34.

[0151] 7(a) and 7(b) are diagrams showing the exposure light source 28, and are schematic diagrams showing a state in which a plurality of light-emitting sections 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 direction of the axis about which the photoconductor 27 rotates. This direction can also be called the long axis direction of the photoconductor 27. FIG. 7(a) shows a form in which the light-emitting sections 36 are arranged along the long axis direction of the photoconductor 27. FIG. 7(b) shows a form different from FIG. 7(a), in which the light-emitting sections 36 are alternately arranged in the column direction in each of the first column and the second column. The first column and the second column are arranged at different positions in the row direction. In the first column, a plurality of light-emitting sections 36 are arranged at intervals. In the second column, the light-emitting sections 36 are located at positions corresponding to the intervals between the light-emitting sections 36 in the first column. That is, a plurality of light-emitting sections 36 are also arranged at intervals in the row direction. The arrangement in FIG. 7(b) can also be described as a grid-like arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0152] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to achieve a display with good image quality and stability even over a long period of time. EXAMPLES

[0153] The present invention will be described below with reference to examples, but the present invention is not limited to these.

[0154] Example 1 (Synthesis of Exemplary Compound C-1) Exemplary compound C-1 was synthesized according to the following scheme.

[0155] [ka]

[0156] (1) Synthesis of compound m-3 The following reagents and solvents were placed in a 500 ml recovery flask. Compound m-1: 5.26g (20.0mmol) THF: 150ml Next, the reaction solution was cooled to -78°C under a nitrogen stream, and 35 ml (21.0 mmol) of nBuLi (0.6 M) was added dropwise. After the addition, the reaction solution was stirred at room temperature for 2 hours. The reaction solution was cooled again to -78°C, and 30 ml of a THF solution containing 4.7 g (22.0 mmol) of compound m-2 was added dropwise. After the addition, the reaction solution was stirred at room temperature for 2 hours. The reaction solution was poured into ice water, extracted with toluene, and the organic layer was concentrated to dryness to obtain a solid.

[0157] Next, the solid was dissolved in 150 ml of acetic acid under a nitrogen stream, and 3 ml of concentrated hydrochloric acid was added dropwise at room temperature. The reaction solution was stirred at room temperature for 5 hours. After the reaction was completed, the reaction solution was poured into ice water, and the precipitated solid was filtered. The filtered solid was purified by silica gel column chromatography (toluene:ethyl acetate mixture) to obtain 4.6 g of m-3 (yield: 62%).

[0158] (2) Synthesis of compound m-4 The following reagents and solvents were placed in a 300 ml recovery flask. Compound m-3: 4.5g (12.2mmol) Sodium thioethanol: 2.05g (24.4mmol) DMF: 140ml Next, the reaction solution was heated and stirred at 60° C. for 24 hours under a nitrogen stream. After the reaction was completed, 100 ml of dilute hydrochloric acid was added and filtered. 4.5 g of m-4 was obtained (yield: 96%).

[0159] (3) Synthesis of compound m-6 The following reagents and solvents were placed in a 200 ml recovery flask. Compound m-4: 4.5g (11.7mmol) Compound m-5: 1.6g (12.9mmol) Potassium carbonate: 4.8 g (35.1 mmol) DMF: 90ml Next, the reaction solution was heated and stirred at 100°C for 24 hours under a nitrogen stream. After the reaction was completed, 100 ml of water was added and filtered. The obtained solid was purified by silica gel column chromatography (toluene:ethyl acetate mixture) to obtain 3.4 g of m-6 (yield: 63%).

[0160] (4) Synthesis of compound m-7 The following reagents and solvents were placed in a 200 ml recovery flask. Compound m-6: 3.4g (7.26mmol) Sodium hydroxide: 2.1 g (52.4 mmol) Ethanol: 35ml Water: 35ml Next, the reaction solution was heated under reflux and stirred for 7 hours under a nitrogen stream. After the reaction was completed, 100 ml of water was added, extracted with ethyl acetate, and the organic layer was concentrated to dryness. The obtained solid was dispersed and washed with toluene to obtain 2.7 g of m-7 (yield: 75%).

[0161] (5) Synthesis of compound m-8 The following reagents and solvents were placed in a 200 ml recovery flask. Compound m-7: 2.7g (5.45mmol) Sulfuric acid: 30ml Next, the reaction solution was stirred at 100°C for 7 hours under a nitrogen stream. After the reaction was completed, the reaction solution was poured into ice water and filtered. The obtained solid was purified by silica gel column chromatography (chlorobenzene:ethyl acetate mixture) to obtain 1.2 g of m-8 (yield: 45%).

[0162] (6) Synthesis of Compound C-1 The following reagents and solvents were placed in a 500 ml recovery flask. Compound m-8: 1.2g (2.45mmol) Compound m-9: 0.497g (2.94mmol) Sodium tert-butylate: 0.47g (4.90mmol) Pd(dba) 2 : 70mg Tri-tert-butylphosphine: 74mg Orthoxylene: 30ml Next, the reaction solution was heated and stirred at 140°C for 5 hours under a nitrogen stream. After the reaction was completed, the mixture was filtered through Celite and concentrated to dryness. The obtained solid was purified by silica gel column chromatography (toluene:ethyl acetate mixture) to obtain 1.1 g of a yellow solid C-1 (yield: 73%).

[0163] Mass spectrometry of the exemplary compound C-1 was carried out using a MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker). [MALDI-TOF-MS] Measured value: m / z=601 Calculated value: C 44 H 27 NO 2 =601

[0164] <Examples 2 to 11 (Synthesis of Exemplary Compounds)> As shown in Table 3, the exemplary compounds shown in Examples 2 to 11 were synthesized in the same manner as in Example 1, except that raw material m-1 in Example 1 was replaced with raw material 1, raw material m-2 with raw material 2, m-5 with raw material 3, and m-9 with raw material 4. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 1 are also shown.

[0165] [Table 3]

[0166] <Example 12 (Synthesis of Exemplary Compound F-1)> Exemplary compound F-1 was synthesized according to the following scheme.

[0167] [ka]

[0168] (1) Synthesis of compound n-3 The following reagents and solvents were placed in a 200 ml recovery flask. Compound n-1: 3.4 g (10.0 mmol) Compound n-2: 2.2g (11.0mmol) Sodium carbonate: 5.3 g (50.0 mmol) Pd(PPh 3 ) 2 Cl 2 :35mg Toluene: 35 ml Water: 35ml Ethanol: 10ml Next, the reaction solution was heated and stirred at 60°C for 5 hours under a nitrogen stream. After the reaction was completed, the mixture was filtered through Celite and concentrated to dryness. The resulting solid was purified by silica gel column chromatography (toluene:ethyl acetate mixture) to obtain 1.6 g of a yellow solid (yield: 43%).

[0169] (2) Synthesis of compound m-5 The following reagents and solvents were placed in a 200 ml recovery flask. Compound n-3: 1.6g (4.30mmol) THF: 80ml Next, the reaction solution was cooled to -78°C under a nitrogen stream, and 8.3 ml (5.00 mmol) of nBuLi (0.6 M) was added dropwise. After the addition, the reaction solution was stirred at room temperature for 2 hours. The reaction solution was cooled again to -78°C, and 10 ml of a THF solution containing 1.8 g (8.60 mmol) of compound n-4 was added dropwise. After the addition, the reaction solution was stirred at room temperature for 2 hours. After the reaction, the mixture was poured into ice water, extracted with toluene, and the organic layer was concentrated to dryness to obtain a solid.

[0170] Next, the solid was dissolved in 80 ml of acetic acid under a nitrogen stream, and 1.5 ml of concentrated hydrochloric acid was added dropwise at room temperature. The reaction solution was stirred at room temperature for 5 hours. After the reaction was completed, the reaction solution was poured into ice water, and the precipitated solid was filtered. The filtered solid was purified by silica gel column chromatography (toluene:ethyl acetate mixture) to obtain 1.4 g of n-5 (yield: 65%).

[0171] (3) Synthesis of compound F-1 The following reagents and solvents were placed in a 200 ml recovery flask. Compound n-5: 1.3g (2.69mmol) Compound n-6:0.499g(2.95mmol) Sodium tert-butylate: 0.47g (4.90mmol) Pd(dba) 2 : 75mg Tri-tert-butylphosphine: 82mg Orthoxylene: 30ml Next, the reaction solution was heated and stirred at 140°C for 5 hours under a nitrogen stream. After the reaction was completed, the mixture was filtered through Celite and concentrated to dryness. The obtained solid was purified by silica gel column chromatography (toluene:ethyl acetate mixture) to obtain 1.1 g of a yellow solid C-1 (yield: 68%).

[0172] Mass spectrometry was carried out on the exemplary compound C-1 in the same manner as in Example 1. [MALDI-TOF-MS] Measured value: m / z=617 Calculated value: C 44 H 27 NSO=617

[0173] <Examples 13 to 19 (Synthesis of Exemplary Compounds)> As shown in Table 4, the exemplary compounds shown in Examples 13 to 19 were synthesized in the same manner as in Example 12, except that raw material n-1 in Example 1 was replaced with raw material 1, raw material n-2 with raw material 2, n-4 with raw material 3, and n-6 ​​with raw material 4. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 12 are also shown.

[0174] [Table 4]

[0175] <Example 20> In this example, an organic EL element having a bottom emission structure was fabricated in which 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 were successively formed on a substrate.

[0176] First, an ITO film was formed on a glass substrate, and an ITO electrode (anode) was formed by performing a desired patterning process. At this time, the film thickness of the ITO electrode was set to 100 nm. The substrate on which the ITO electrode was formed in this manner was used as an ITO substrate in the following process. Next, vacuum deposition was performed by resistance heating in a vacuum chamber to continuously form an organic compound layer and an electrode layer shown in Table 5 on the ITO substrate. At this time, the electrode area of ​​the opposing electrodes (metal electrode layer, cathode) was 3 mm2. 2 It was made so that:

[0177] [Table 5]

[0178] The characteristics of the obtained element were measured and evaluated. As an initial characteristic of light emission, green light emission with a maximum external quantum efficiency (EQE) of 5.8% was obtained. Specifically, the current-voltage characteristics were measured with a Hewlett-Packard 4140B microammeter, and the light emission luminance was measured with a Topcon BM7. Furthermore, the current density was 50 mA / cm. 2 A continuous driving test was conducted at 400 rpm, and the time until the brightness degradation rate reached 5% (LT95) was measured, which was 112 hours.

[0179] <Examples 21 to 25> An organic light-emitting device was produced in the same manner as in Example 20, except that the compounds in Example 20 were appropriately changed to those shown in Table 6. The characteristics of the obtained device were measured and evaluated in the same manner as in Example 20. The measurement results are shown in Table 6.

[0180] [Table 6]

[0181] <Example 26> An organic light-emitting device was produced in the same manner as in Example 17, except that the organic compound layer and the electrode layer shown in Table 7 were successively formed.

[0182] [Table 7]

[0183] The characteristics of the obtained element were measured and evaluated in the same manner as in Example 20. As the initial light emission characteristics, green light emission with a maximum external quantum efficiency (EQE) of 6.8% was obtained. Furthermore, at a current density of 50 mA / cm 2 A continuous driving test was conducted at 400 rpm, and the time until the brightness degradation rate reached 5% (LT95) was measured, which was 153 hours.

[0184] <Examples 27 to 44, Comparative Examples 1 and 2> An organic light-emitting device was produced in the same manner as in Example 26, except that the compounds in Example 26 were appropriately changed to those shown in Table 8. The characteristics of the obtained device were measured and evaluated in the same manner as in Example 26. The measurement results are shown in Table 8. The guest materials used in the comparative examples are shown below.

[0185] [ka]

[0186] [Table 8]

[0187] From Table 8, the maximum external quantum efficiency (EQE) of Comparative Example 1 and Comparative Example 2 is low, at 4.0 or less. 1 and T 1 This is because the difference in the amount of delayed fluorescence is large, and there is no emission component due to delayed fluorescence. On the other hand, the element using the compound of the present invention has a carbonyl group and an amino group, so S 1 and T 1 The difference between the LT95 and LT96 values ​​was small, and the emission was highly efficient due to delayed fluorescence. Comparative Examples 1 and 2 also showed poor durability, with a 5% degradation lifespan (LT95) of 50 hours or less. This is believed to be due to the high planarity of the center of the molecule, which leads to molecular association. On the other hand, the element using the compound of the present invention showed good durability, with a 5% degradation lifespan of 100 hours or more. The element showed good durability due to the presence of a spiro structure in the center of the molecule that is less susceptible to concentration quenching. [Explanation of symbols]

[0188] 10: display device, 11: substrate, 12: moisture-proof film, 13: gate electrode, 14: gate insulating film, 15: semiconductor layer, 16: drain electrode, 17: source electrode, 18: TFT element, 19: insulating film, 20: contact hole, 21: anode, 22: organic compound layer, 23: cathode, 24: first protective layer, 25: second protective layer, 26: organic light-emitting element< / y>

Claims

1. An organic compound represented by the following general formula [1] or [2]: 【Chemistry 1】 In the formula [1] or [2], X 1 ~X 18 , X 21 ~X 38 are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a trimethylsilyl group, a triphenylsilyl group, and a cyano group. 1 ~X 8 At least one of the X 21 ~X 28 At least one of the X's is a substituted or unsubstituted amino group. The groups bonded to the nitrogen atoms of the substituted or unsubstituted amino groups may be bonded to each other to form a ring structure. The groups bonded to the nitrogen atoms of the substituted or unsubstituted amino groups may be bonded to each other to form a ring structure. 1 ~X 8 Either X 21 ~X 28 The group bonded to the nitrogen atom of the substituted or unsubstituted amino group may be bonded to the adjacent X through oxygen or sulfur to form a ring. 1 ~X 8 Either X 21 ~X 28 may be bonded to any one of the groups to form a ring. The substituent that the alkyl group, the alkoxy group, the amino group, the aryl group, the heterocyclic group, the aryloxy group, and the heteroaryloxy group may have is an alkyl group, an aralkyl group, an aryl group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, a halogen atom, or a cyano group. Y represents oxygen, sulfur, selenium, tellurium, or a CR1R2 group. 1 ~R 2 are each independently selected from a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a trimethylsilyl group, a triphenylsilyl group, and a cyano group. The substituents which the alkyl group, the alkoxy group, the amino group, the aryl group, the heterocyclic group, the aryloxy group, and the heteroaryloxy group represented by R 1 to R 2 may have are an alkyl group, an aralkyl group, an aryl group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, a halogen atom, or a cyano group.

2. The X 2 , X 3 , X 6 , X 7 At least one of X 22 , X 23 , X 26 , X 27 2. The organic compound according to claim 1, wherein at least one of said amino groups is a substituted or unsubstituted amino group.

3. The X 1 , X 4 , X 5 , X 8 At least one of X 21 , X 24 , X 25 , X 28 2. The organic compound according to claim 1, wherein at least one of said amino groups is a substituted or unsubstituted amino group.

4. 4. The organic compound according to claim 1, wherein Y is oxygen.

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

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

7. The organic light-emitting device according to claim 6 , wherein the light-emitting layer further comprises a host material.

8. The organic light-emitting device according to claim 7 , wherein the host material is a hydrocarbon compound.

9. The organic light-emitting device according to claim 7 , wherein the light-emitting layer further comprises a light-emitting material.

10. The organic light-emitting device according to claim 9 , wherein the light-emitting material is a hydrocarbon compound.

11. The organic light-emitting device according to claim 6 , wherein the light-emitting layer emits green or red light.

12. A display device comprising a plurality of pixels, at least one of the plurality of pixels comprising the organic light-emitting element according to claim 5 and a transistor connected to the organic light-emitting element.

13. an optical unit having a plurality of lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image captured by the image sensor; The photoelectric conversion device, wherein the display section comprises the organic light-emitting element according to claim 5 .

14. 12. An electronic device comprising: a display unit having the organic light-emitting element according to claim 5; a housing in which the display unit is provided; and a communication unit provided in the housing and configured to communicate with an external device.

15. 12. An illumination device comprising: a light source having the organic light-emitting element according to claim 5; and a light diffusion section or an optical filter that transmits light emitted by the light source.

16. A moving body comprising: a lighting device having the organic light-emitting element according to claim 5; and a body on which the lighting device is provided.

17. An exposure light source for an electrophotographic image forming apparatus, comprising the organic light emitting device according to claim 5 .

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