Organic compound, organic light emitting element, display device, photoelectric conversion device, electronic device, lighting device, and exposure light source

Abstract

The present application relates to an organic compound, an organic light emitting element, a display device, a photoelectric conversion device, an electronic device, an illumination device, and an exposure light source. Provided is an organic compound represented by general formula [1]. Ring A is a polycyclic aromatic hydrocarbon ring having a fluoranthene skeleton and having 16 to 60 carbon atoms, and optionally has an alkyl group or the like as a substituent, which is substituted or unsubstituted. Ring B1 and ring B2 are aromatic hydrocarbon rings having 6 to 18 carbon atoms, and each has two or more electron-withdrawing groups. Q1 and Q2 respectively represent one electron-withdrawing group of ring B1 and one electron-withdrawing group of ring B2, and Q1 and Q2 are respectively located at the ortho position of ring B1 and the ortho position of ring B2 with respect to ring A.

Description

[0001] This application is a divisional application of Chinese patent application filed on September 2, 2020, with application number 202010909375.5 and entitled "Organic Compound, Organic Light Emitting Element, Display Device, Photoelectric Conversion Device, Electronic Device, Lighting Device and Exposure Light Source". Technical Field

[0002] This invention relates to organic compounds, organic light-emitting elements, display devices, photoelectric conversion devices, electronic devices, lighting devices, moving objects, and exposure light sources. Background Technology

[0003] Organic light-emitting elements, particularly organic electroluminescent elements (hereinafter referred to as "organic EL elements"), are electronic devices comprising a pair of electrodes and an organic compound layer disposed between the electrodes. By injecting electrons and holes through this pair of electrodes, excitons of luminescent organic compounds in the organic compound layer are generated. When the excitons return to their ground state, the organic light-emitting element emits light.

[0004] Recent significant advances in organic light-emitting elements have enabled low driving voltages, a wide range of emission wavelengths, high-speed response, and the thinning and weight reduction of light-emitting devices.

[0005] To date, luminescent organic compounds have been actively developed. This is because it is important to create compounds with good luminescent properties in order to provide high-performance organic light-emitting elements. As a compound that has been developed to date, Japanese Patent Application Publication No. 11-40360 discloses the following compound 1-A.

[0006]

[0007] The inventors' research has shown that, as described below, compound 1-A has a low oxidation potential and inherently low stability. Therefore, organic light-emitting elements containing this compound exhibit poor durability. Summary of the Invention

[0008] This invention provides organic compounds with high oxidation potential and high chemical stability. This invention also provides organic light-emitting elements with high driving durability.

[0009] Organic compounds according to one aspect of the present invention are represented by the following general formula [1].

[0010]

[0011] In formula [1], ring A is a polycyclic aromatic hydrocarbon ring having a fluoranthene skeleton and having 16 to 60 carbon atoms, and optionally having 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, or a silyl group as a substituent.

[0012] Ring B1 and ring B2 are aromatic hydrocarbon rings with 6 to 18 carbon atoms, and each has more than two electron-withdrawing groups.

[0013] Q1 and Q2 represent an electron-withdrawing group in ring B1 and an electron-withdrawing group in ring B2, respectively, and are located in the adjacent positions of ring B1 and ring B2 relative to ring A.

[0014] Further features of the invention will become apparent from the following description of exemplary embodiments, with reference to the accompanying drawings. Attached Figure Description

[0015] Figure 1 The structures of exemplary compound A17 and comparative compound (6) according to embodiments of the present invention are shown.

[0016] Figure 2 This is a schematic cross-sectional view illustrating an example of a display device including an organic light-emitting element according to an embodiment of the present invention.

[0017] Figure 3 An example of a display device according to an embodiment of the present invention is shown schematically.

[0018] Figure 4A An example of a camera device according to an embodiment of the present invention is shown schematically. Figure 4B Examples of electronic devices according to embodiments of the present invention are shown schematically.

[0019] Figure 5A An example of a display device according to an embodiment of the present invention is shown schematically. Figure 5B An example of a foldable display device is shown schematically.

[0020] Figure 6A An example of a lighting device according to an embodiment of the present invention is shown schematically. Figure 6B An example of a car including a vehicle lighting device according to an embodiment of the present invention is shown schematically.

[0021] Figure 7 An example of an image forming apparatus according to an embodiment of the present invention is illustrated schematically.

[0022] Figure 8A and Figure 8BAn example of an exposure light source used in an image forming apparatus according to an embodiment of the present invention is shown schematically. Detailed Implementation

[0023] <Organic Compounds>

[0024] First, the organic compound according to this embodiment will be described. The organic compound according to this embodiment is an organic compound represented by the following general formula [1].

[0025]

[0026] In formula [1], ring A is a polycyclic aromatic hydrocarbon ring having a fluoranthene skeleton and having 16 to 60 carbon atoms, for example, 16 to 40 carbon atoms.

[0027] Ring A can be, for example, FF1 to FF42, but is not limited to these. Ring A can be FF1 to FF16.

[0028]

[0029]

[0030] Ring A may optionally have 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, and a silyl group as substituents.

[0031] Non-limiting examples of halogen atoms optionally included as substituents in ring A include fluorine, chlorine, bromine, and iodine.

[0032] Non-limiting examples of alkyl groups optionally included as substituents in ring A include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, octyl, cyclohexyl, 1-adamantyl, and 2-adamantyl. The alkyl group optionally included as a substituent in ring A is, for example, an alkyl group having 1 to 10 carbon atoms.

[0033] Non-limiting examples of alkoxy groups optionally included as substituents in ring A include methoxy, ethoxy, propoxy, 2-ethyl-octoxy, and benzyloxy. Alkoxy groups optionally included as substituents in ring A are, for example, alkoxy groups having 1 to 6 carbon atoms.

[0034] Non-limiting examples of amino groups optionally included as substituents in ring A include N-methylamino, N-ethylamino, N,N-dimethylamino, N,N-diethylamino, N-methyl-N-ethylamino, N-benzylamino, N-methyl-N-benzylamino, N,N-dibenzylamino, aniline, N,N-diphenylamino, N,N-dinaphthylamino, N,N-difluorenylamino, N-phenyl-N-tolylamino, N,N-dimethylmethylamino, N-methyl-N-phenylamino, N,N-diphenylmethyl etherylamino, N-trimethylyl-N-phenylamino, N,N-ditrimethylylmethylamino, N-phenyl-N-(4-tert-butylphenyl)amino, N-phenyl-N-(4-trifluoromethylphenyl)amino, and N-piperidinyl.

[0035] Non-limiting examples of aryl groups optionally included as substituents in ring A include phenyl, naphthyl, indene, biphenyl, terphenyl, fluorenyl, phenanthrene, fluoranyl, and triphenylene. The aryl group optionally included as a substituent in ring A is, for example, an aryl group having 6 to 18 carbon atoms.

[0036] Non-limiting examples of heterocyclic groups optionally included as substituents in ring A include pyridinyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazole, acridinel, phenanthrolinel, dibenzofuranyl, and dibenzothiophenel. The heterocyclic group optionally included as a substituent in ring A is, for example, a heterocyclic group having 3 to 15 carbon atoms.

[0037] Non-limiting examples of aryloxy groups optionally included as substituents in ring A include phenoxy and thiophenoxy.

[0038] Non-limiting examples of silyl groups optionally included as substituents in ring A include trimethylsilyl and triphenylsilyl.

[0039] Non-limiting examples of substituents that may be further introduced into alkyl, alkoxy, amino, aryl, heterocyclic, and aryloxy groups include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl; aralkyl groups such as benzyl; aryl groups such as phenyl and biphenyl; heterocyclic groups such as pyridyl and pyrrole; amino groups such as dimethylamino, diethylamino, dibenzylamino, diphenylamino, and xylylamino; alkoxy groups such as methoxy, ethoxy, and propoxy; aryloxy groups such as phenoxy; halogen atoms such as fluorine, chlorine, bromine, and iodine; and cyano groups.

[0040] In formula [1], ring B1 and ring B2 are aromatic hydrocarbon rings with 6 to 18 carbon atoms, and each has more than two electron-withdrawing groups. Non-limiting examples of ring B1 and ring B2 include benzene rings, naphthalene rings, phenanthrene rings, fluorene rings, fluoranthene rings, pyrene rings, anthracene rings, and triphenylene rings. Among them, from the viewpoint of sublimation, ring B1 and ring B2 can be benzene rings or naphthalene rings with low molecular weight. Ring B1 and ring B2 can have the same structure.

[0041] Rings B1 and B2 may have substituents other than electron-withdrawing groups. Examples of substituents other than electron-withdrawing groups that may be included in rings B1 and B2 include halogen atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted amino groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heterocyclic groups, substituted or unsubstituted aryloxy groups, and silyl groups. Specific examples of substituents are the same as those described as substituents optionally included in ring A. Rings B1 and B2 may be substituted or unsubstituted alkyl groups.

[0042] In formula [1], Q1 and Q2 represent an electron-withdrawing group of ring B1 and an electron-withdrawing group of ring B2, respectively, and are located at the ortho position of ring B1 relative to ring A and the ortho position of ring B2 relative to ring A, respectively. Non-limiting examples of Q1 and Q2 include fluorine, trifluoromethyl, and cyano. From the viewpoint of the stability of the compound, i.e., the durability of the element, Q1 and Q2 can represent a cyano group with high bond energy due to its triple bond. Q1 and Q2 can represent the same electron-withdrawing group.

[0043] Next, a method for synthesizing the organic compound according to this embodiment will be described. The organic compound according to this embodiment is synthesized via, for example, the following reaction process.

[0044]

[0045] In this document, compounds represented by general formula [1] can be obtained by appropriately changing the starting materials and the compounds represented by (a) to (c) above and reacting with the starting materials. The synthetic methods will be described in detail in the examples.

[0046] Because the organic compound according to this embodiment has the following characteristics, it is a compound with high oxidation potential, high chemical stability, and high sublimation rate. Furthermore, by using this organic compound, an organic light-emitting element with high durability can be provided.

[0047] The term "basic skeleton" in this document refers to a skeleton that includes a fluoranthene skeleton and in which the polycyclic aromatic hydrocarbon ring represented by ring A is unsubstituted. Hereinafter, rings B1 and B2 may be collectively referred to as "ring B," and Q1 and Q2 may be collectively referred to as "electron-withdrawing groups Q."

[0048] (1) The fluoranthene skeleton exists in the basic skeleton, ring B has more than two electron-withdrawing groups, and at least one electron-withdrawing group is located in the ortho position relative to ring A.

[0049] (2) Provide electron-withdrawing groups Q to cover the basic skeleton.

[0050] These features will be described below.

[0051] (1) The fluoranthene skeleton exists in the basic skeleton, ring B has more than two electron-withdrawing groups, and at least one electron-withdrawing group is located in the ortho position relative to ring A.

[0052] In creating the organic compound represented by formula [1], the inventors focused on the basic skeleton and substituents. In the organic compound according to this embodiment, the basic skeleton represented by ring A is a polycyclic aromatic hydrocarbon ring having a fluoranthene skeleton, the substituent represented by ring B has two or more electron-withdrawing groups, and at least one electron-withdrawing group is substituted at an ortho position of ring B relative to ring A.

[0053] Fluoranthracene is an aromatic hydrocarbon with a five-membered ring. Aromatic hydrocarbons with a five-membered ring are characterized as follows: These aromatic hydrocarbons have a 5π electron system. If an aromatic hydrocarbon accepts an electron (is reduced), it has a 6π electron system, which, according to Hückel's rule, leads to aromatic stabilization. Therefore, compared to aromatic hydrocarbons consisting only of six-membered rings (such as anthracene and pyrene), fluoranthracene has better electron accepting and poorer electron donating properties. In other words, fluoranthracene is not readily electron-donating and therefore exhibits high oxidation stability. Thus, the basic skeleton represented by ring A and having the fluoranthracene skeleton itself possesses high oxidation stability.

[0054] Furthermore, the substituent represented by ring B has two or more electron-withdrawing groups, at least one of which is located ortho-to ring A. This improves oxidative stability.

[0055] High oxidative stability indicates that the compound itself is not easily oxidized and possesses high chemical stability. High chemical stability means the compound is stable and does not readily undergo chemical reactions. In organic light-emitting elements (OLEDs), when the organic compound sandwiched between electrodes is repeatedly oxidized and reduced between its molecules, carrier transport occurs, and carrier recombination causes the organic compound to repeatedly possess excited and ground states. Therefore, the OLED emits light. Compounds with low chemical stability are unsuitable because such compounds undergo chemical reactions through redox processes and in the excited state, transforming into different compounds, which impairs the inherent element characteristics, i.e., reduces brightness.

[0056] The oxidative stability of the organic compound according to the embodiment will be described by comparing it with a comparative compound having a similar structure. In this document, the comparative compounds are the comparative compounds (1) to (5) listed in Table 1. Comparative compounds (1) to (5) are compounds having a basic skeleton similar to that of compound 1-A disclosed in Japanese Patent Application Publication No. 11-40360.

[0057] An organic compound according to this embodiment is the exemplary compound A1 listed in Table 1. The exemplary compound A1 is a compound in which, in general formula [1], ring A is the basic skeleton of compound 1-A disclosed in Japanese Patent Application Publication No. 11-40360, rings B1 and B2 are benzene rings, and electron-withdrawing groups Q1 and Q2 are cyano groups.

[0058] In this paper, comparative compounds (1) to (5) and exemplary compound A1 are compared with each other in terms of redox potential by performing cyclic voltammetry (CV) measurements. The results are shown in Table 1. CV measurements were performed using a 0.1 M tetrabutylammonium perchlorate DMF solution (for reduction potential measurement) and a 0.1 M tetrabutylammonium perchlorate dichloromethane solution (for oxidation potential measurement). The reference electrode was Ag / Ag. + The counter electrode was Pt, and the working electrode was glassy carbon. The voltage scan rate was 1.0 V / s. The measuring instrument was an electrochemical analyzer 660C manufactured by ALS.

[0059] Table 1

[0060]

[0061] Table 1 shows that the oxidation potentials of compounds (1) to (5) are 1.03 V, 1.10 V, 1.11 V, 1.15 V and 1.19 V, respectively, while the exemplary compound A1 according to this embodiment has a high oxidation potential of 1.21 V. In other words, the exemplary compound A1 is a compound that is not easily oxidized.

[0062] The reasons are as follows. A comparison between compounds (2) and (4) shows that the oxidation potential of the comparative compound (4), which has a cyano group located in the ortho position, is the highest at 1.15 V. This indicates that when an electron-withdrawing group is introduced, the substitution position that increases the oxidation potential and makes the greatest contribution to oxidation stability is the ortho position. This is likely because the highest occupied molecular orbital (HOMO) exists in the basic skeleton represented by ring A, and the substitution position with the shortest distance between ring A and the electron-withdrawing group via ring B is the ortho position, which maximizes the electron-withdrawing effect, i.e., the greatest contribution to increasing the oxidation potential. Furthermore, the organic compound according to this embodiment further has one or more electron-withdrawing groups in positions other than the ortho position, thus having a high oxidation potential and being stable as a compound. Therefore, the organic light-emitting element containing this compound has high stability and high durability.

[0063] (2) Provide electron-withdrawing groups Q to cover the basic skeleton.

[0064] Typically, polycyclic aromatic hydrocarbons (PAHs) exhibit high molecular planarity, leading to increased molecular packing. This packing unfavorably increases crystallinity, reducing sublimability and causing concentration quenching. In other words, reducing molecular packing improves sublimability and suppresses concentration quenching. Improved sublimability can enhance material purity through sublimation purification, enabling the production of organic light-emitting elements (OLEDs) via vapor deposition. This reduces the amount of impurities contained within the OLED. Consequently, the reduction in luminous efficiency and drive durability due to impurities can be suppressed. From the viewpoint of improving the luminous efficiency of OLEDs, reducing concentration quenching is desirable.

[0065] Therefore, the inventors are interested in the molecular structure of substituents. By introducing substituents that cover the central conjugated facet of the basic skeleton, the degree of molecular packing can be reduced. In the organic compound according to this embodiment, it is believed that the arrangement of molecular packing is promoted by the overlap of the π-conjugated facets of the basic skeleton represented by ring A. Therefore, the inventors have attempted to introduce substituents that cover the π-conjugated facets.

[0066] Specifically, such as Figure 1 As shown in the exemplary compound A17, an attempt is made to reduce the degree of molecular stacking by covering the π-conjugated face of the basic skeleton by introducing a cyano group at the ortho position of the benzene ring used as a substituent. Exemplary compound A17 is a compound in which ring A is FF5, rings B1 and B2 are benzene rings, and electron-withdrawing groups Q1 and Q2 are cyano groups in general formula [1]. Comparative compound (6) is a compound that differs from exemplary compound A17 in terms of the substitution position of the electron-withdrawing group in ring B.

[0067] The effect of the substituent represented by ring B will be described by comparing comparative compound (6) and exemplary compound A17. Comparative compound (6) and exemplary compound A17 have the same molecular weight, but the difference between the decomposition temperature and the sublimation temperature of exemplary compound A17 is greater than that of comparative compound (6). As the difference between the decomposition temperature and the sublimation temperature increases, the temperature margin in sublimation purification increases, which achieves excellent sublimability.

[0068] This is likely because the angle (dihedral angle) between the basic skeleton and ring B is 56° in the comparative compound (6), while in the exemplary compound A17 the angle is as large as 70°, which inhibits the overlap of the π conjugated surfaces of the basic skeleton.

[0069] This is likely because the cyano group physically inhibits the overlap of the π-conjugated planes of the basic framework, and the addition of negative charge by the nitrogen atom with high electronegativity generates a repulsive force between the cyano groups, which inhibits the overlap of the π-conjugated planes.

[0070] That is, when an organic compound has an electron-withdrawing group at the ortho position of ring B, the degree of molecular packing can be reduced, which provides a compound with high sublimation and suppressed concentration quenching. Therefore, organic light-emitting elements containing this compound have high driving durability and exhibit high-efficiency light-emitting characteristics.

[0071] The sublimation temperature is 1×10 -1 The organic compound was gradually heated under a vacuum of Pa in an Ar-flowing atmosphere until it began to sublimate and was purified, and the sublimation rate reached a sufficient level. The decomposition temperature was determined by TG / DTA measurement at the point where a weight loss of 5% was achieved.

[0072] Therefore, when the organic compound according to this embodiment satisfies conditions (1) and (2), the organic compound is a compound with high oxidative stability and high sublimation.

[0073] Furthermore, an organic compound is suitable as a compound for use in organic light-emitting elements when it meets the following condition (3). This is because meeting condition (3) further improves the effect of reducing the degree of molecular packing.

[0074] (3) Ring B binds to ring A at the position with the largest dihedral angle between the fluoranthene skeleton and ring B.

[0075] The organic compound according to this embodiment has a high degree of planarity in its basic skeleton represented by ring A. If the organic compound is unsubstituted, the degree of molecular packing increases. The organic compound according to this embodiment may have substituents on ring A. These substituents are selected from the group consisting of phenyl, naphthyl, and phenanthrene. Phenyl is more suitable. Substituent positions that can effectively reduce the degree of molecular packing will be described herein.

[0076] The degree of molecular packing, i.e., the π-π interactions between molecules, increases with the expansion of the π plane. To reduce π-π interactions, the inventors focused on the dihedral angle between ring A, which serves as the basic framework, and ring B, which serves as a substituent. In this paper, the dihedral angle between the basic framework and the substituent is estimated using molecular orbital calculations of fluoranthene (which is the smallest unit of ring A, which serves as the basic framework) and benzene (which is the smallest unit of ring B, which serves as a substituent).

[0077] As a computational technique for molecular orbital calculations, density functional theory (DFT), which is now widely used, is employed. The functional is B3LYP, and the basis functions are 6-31G. *Molecular orbital calculation is performed by using the currently widely used Gaussian09 (Gaussian09, Revision C.01, M.J.Frisch, G.W.Trucks, H.B.Schlegel, G.E.Scuseria, M.A.Robb, J.R.Cheeseman, G.Scalmani, V.Barone, B.Mennucci, G.A.Petersson, H.Nakatsuji, M.Caricato, X.Li, H.P.Hratchian, A.F.Izmaylov, J.Bloino, G.Zheng, J.L.Sonnenberg, M.Hada, M.Ehara, K.Toyota, R.Fukuda, J.Hasegawa, M.Ishida, T.Nakajima, Y.Honda, O.Kitao, H.Nakai, T.Vreven, J.A.Montgomery, Jr., J.E.Peralta, F.Ogliaro, M.Bearpark, J.J.Heyd, E.Brothers, K.N.Kudin, V.N.Staroverov, T.Keith, R.Kobayashi, J.Normand, K.Raghavachari, A.Rendell, J.C.Burant, S.S.Iyengar, J.Tomasi, M.Cossi, N.Rega, J.M.Millam, M.Klene, J.E.Knox, J.B.Cross, V.Bakken, C.Adamo, J.Jaramillo, R.Gomperts, R.E.Stratmann, O.Yazyev, A.J.Austin, R.Cammi, C.Pomelli, J.W.Ochterski, R.L.Martin, K.Morokuma, V.G.Zakrzewski, G.A.Voth, P.Salvador, J.J.Dannenberg, S.Dapprich, A.D.Daniels, O.Farkas, J.B.Foresman, J.V.Ortiz, J.Cioslowski, and D.J.Fox, Gaussian, Inc., Wallingford CT, 2010.).

[0078] Table 2

[0079]

[0080] Table 2 shows that 7-phenylfluoranthracene has the largest dihedral angle and the shortest wavelength. Due to the largest dihedral angle, the π-π interactions between the basic skeleton (fluoranthracene) can be suppressed by the substituent (benzene). It was also found that the π plane does not expand due to the smallest S1. Therefore, 7-phenylfluoranthracene can most effectively reduce the degree of molecular packing.

[0081] Therefore, ring A has a fluoranthene skeleton represented by the following general formula [2] or a benzo(k)fluoranthene skeleton represented by the following general formula [3], and rings B1 and B2 can be bonded to ring A at either of the * positions in the following general formulas [2] or [3].

[0082]

[0083] When the basic skeleton of ring A with a fluoranthene skeleton is described using the following general formula [4] or [5], the preferred substitution position of ring B for reducing the degree of molecular packing is any of the * positions in general formula [4] or [5].

[0084]

[0085] In formula [4], rings C through E each represent an aromatic hydrocarbon ring, and rings C and D can combine with each other to form a ring. In formula [5], rings F through H each represent an aromatic hydrocarbon ring, and rings F and G can combine with each other to form a ring.

[0086] When an organic compound further satisfies the following condition (4), it can be used specifically as a blue luminescent material. This is because when condition (4) is met, the emission wavelength is short and a deep blue color on the chromaticity coordinates can be reproduced.

[0087] (4) Ring A is a polycyclic aromatic hydrocarbon ring with a fluoranthene skeleton and 16 to 40 carbon atoms.

[0088] The organic compound according to this embodiment has an electron-withdrawing group at the ortho position of ring B, thus exhibiting a high oxidation potential. Therefore, the band gap of the compound itself is larger than that of compounds without electron-withdrawing groups. This indicates a shift in emission wavelength towards shorter wavelengths. With this characteristic, compounds suitable for the desired emission wavelength regions of the material, such as blue, green, yellow, and red emission wavelength regions, can be obtained by adjusting the emission wavelength. In particular, in the blue region, a deeper blue can be reproduced on the blue chromaticity coordinates when the emission wavelength is shorter. Therefore, the characteristics of the organic compound according to this embodiment can be utilized more appropriately.

[0089] In this embodiment, since the luminescence properties (emission wavelength region) themselves depend largely on the π-conjugation degree of ring A, the π-conjugation degree is appropriately small to a certain extent in order to obtain the emission wavelength in the blue region. Specifically, ring A is a polycyclic aromatic hydrocarbon ring with 16 to 40 carbon atoms. Non-limiting examples of polycyclic aromatic hydrocarbons having a fluoranthene skeleton and having 16 to 40 carbon atoms include FF1 to FF16 as described above.

[0090] In this paper, compounds (7) and (8) are compared with exemplary compound A23 in terms of emission wavelength. The results are shown in Table 3. The emission wavelength was measured by photoluminescence measurement of a diluted toluene solution at room temperature with an excitation wavelength of 350 nm using an F-4500 manufactured by Hitachi, Ltd.

[0091] Table 3

[0092]

[0093] Table 3 shows that the emission wavelength of exemplary compound A23 is shifted to a shorter wavelength due to the electron-withdrawing group. Therefore, when the organic compound according to this embodiment satisfies condition (4), it is able to emit blue light with high color purity capable of reproducing deep blue. The chromaticity coordinates of blue will be described in detail in the examples. On the other hand, by introducing an electron-withdrawing group, the emission wavelength of comparative compound (8) is significantly shifted to a longer wavelength. This shows that the emission wavelength can be adjusted by selecting the number and substitution position of the electron-withdrawing groups. The number and substitution position of the electron-withdrawing groups in comparative compound (8) are particularly useful when adjusting the emission wavelength of green or red luminescent materials by shifting it to a longer wavelength.

[0094] Since the organic compound according to this embodiment is a compound possessing the above properties (1) and (2) and further possessing property (3), the organic compound exhibits high oxidative stability and high sublimation. Furthermore, when the organic compound possesses property (4), it emits blue light with a short wavelength. By using this organic compound, a high-efficiency organic light-emitting element with high durability can be provided.

[0095] The organic compounds according to embodiments of the present invention will be described in detail below. However, the present invention is not limited thereto.

[0096]

[0097]

[0098]

[0099]

[0100] Among the exemplary compounds above, those belonging to Group A are compounds in which ring A is a polycyclic aromatic hydrocarbon having a fluoranthene skeleton and having 16 to 40 carbon atoms. The π-conjugation length of the basic skeleton formed by ring A itself corresponds to the band gap of the blue luminescent region. That is, such compounds are suitable as blue dopants as luminescent materials.

[0101] On the other hand, among the exemplary compounds described above, those belonging to Group B are compounds in which the π-conjugation length of the basic backbone formed by ring A itself corresponds to the band gap of the green luminescent region, and in which substituents cause the luminescent region to correspond to the green region. That is, such compounds are suitable as green dopants as luminescent materials.

[0102] Among the exemplary compounds above, those belonging to group C are compounds in which the π-conjugation length of the basic backbone formed by ring A itself corresponds to the band gap of the red luminescent region, and in which substituents cause the luminescent region to correspond to the red region. That is, such compounds are suitable as red dopants as luminescent materials.

[0103] In this specification, blue dopant refers to a luminescent material having a peak wavelength of 430 nm to 480 nm in its emission spectrum. Green dopant refers to a luminescent material having a peak wavelength of 500 nm to 570 nm in its emission spectrum. Red dopant refers to a luminescent material having a peak wavelength of 580 nm to 680 nm in its emission spectrum.

[0104] Organic light-emitting elements

[0105] The organic light-emitting element according to an embodiment of the present invention will be described below.

[0106] The organic light-emitting element according to this embodiment includes at least an anode and a cathode as a pair of electrodes, and an organic compound layer disposed between the electrodes. In the organic light-emitting element according to this embodiment, the organic compound layer may have a single-layer structure or a multilayer structure including multiple layers, as long as the organic compound layer includes a light-emitting layer.

[0107] When the organic compound layer has a multilayer structure comprising multiple layers, in addition to the light-emitting layer, the organic compound layer may also include a hole injection layer, a hole transport layer, an electron blocking layer, a hole / exciton blocking layer, an electron transport layer, and an electron injection layer. The light-emitting layer may have a single-layer structure or a multilayer structure comprising multiple layers.

[0108] In the organic light-emitting element according to this embodiment, at least one layer of the organic compound layer contains the organic compound according to this embodiment. Specifically, the organic compound according to this embodiment is contained in any one of the hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole / exciton blocking layer, electron transport layer, and electron injection layer. The organic compound according to this embodiment may be contained in the light-emitting layer.

[0109] In the organic light-emitting element according to this embodiment, when the light-emitting layer contains the organic compound according to this embodiment, the light-emitting layer may be a layer formed solely of the organic compound according to this embodiment, or it may be a layer formed of the organic compound according to this embodiment and other compounds. When the light-emitting layer is a layer formed of the organic compound according to this embodiment and other compounds, the organic compound according to this embodiment may be used as a host or a guest of the light-emitting layer. Optionally, the organic compound may be used as an auxiliary material that can be included in the light-emitting layer. In this document, a host refers to the compound having the highest mass ratio among the compounds constituting the light-emitting layer. A guest refers to a compound having a lower mass ratio than the host among the compounds constituting the light-emitting layer and being responsible for the main light emission. An auxiliary material refers to a compound having a lower mass ratio than the host among the compounds constituting the light-emitting layer and assisting the guest in light emission. The auxiliary material is also referred to as a second host.

[0110] When the organic compound according to this embodiment is used as a guest in the luminescent layer, the concentration of the guest relative to the entire luminescent layer may be more than 0.01% by mass and less than 20% by mass, or it may be more than 0.1% by mass and less than 5% by mass.

[0111] When the organic compound according to this embodiment is used as the guest of the light-emitting layer, a material having a higher LUMO energy level than the organic compound according to this embodiment (a material having a LUMO energy level closer to the vacuum energy level) can be used as the host. This is because when a material having a higher LUMO energy level than the organic compound according to this embodiment is used as the host, the organic compound according to this embodiment can receive a larger number of electrons supplied to the host of the light-emitting layer.

[0112] As a result of in-depth research, the inventors have discovered that when an organic compound according to this embodiment is used as the host or guest of the light-emitting layer, particularly as the guest of the light-emitting layer, an element that produces light output with high efficiency and high brightness and has very high durability is provided. The light-emitting layer can have a single-layer structure or a multi-layer structure, or the light emission color of this embodiment can be mixed with other colors by adding a light-emitting material having other emission colors. A multi-layer structure refers to a state in which the light-emitting layer and other light-emitting layers are stacked. In this case, the emission color of the organic light-emitting element is not limited to red. The emission color can specifically be white or an intermediate color. In the case of white, the other light-emitting layers emit light with colors other than red (e.g., blue or green). The light-emitting layer is formed by methods such as vapor deposition or coating. Details of this method will be specifically described in the following embodiments.

[0113] The organic compound according to this embodiment can be used as a material for organic compound layers other than the light-emitting layer constituting the organic light-emitting element according to this embodiment. Specifically, the organic compound can be used as a material for, for example, an electron transport layer, an electron injection layer, a hole transport layer, a hole injection layer, and a hole blocking layer.

[0114] The organic compound according to this embodiment can be used as needed in combination with, for example, known low-molecular-weight compounds or high-molecular-weight compounds, such as hole-injecting compounds or hole-transporting compounds, compounds used as a host, luminescent compounds, electron-injecting compounds, or electron-transporting compounds. Examples of such compounds will be described below.

[0115] Hole-injecting or transporting materials are suitable for having high hole mobility, thereby facilitating the injection of holes from the anode and transporting the injected holes to the light-emitting layer. Hole-injecting or transporting materials are also suitable for having high glass transition temperatures to suppress film quality degradation, such as crystallization in organic light-emitting elements. Examples of low-molecular-weight or high-molecular-weight materials with hole-injecting or transporting properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. These hole-injecting or transporting materials are also suitable for use in electron blocking layers. The following are non-limiting specific examples of compounds used as hole-injecting or transporting materials.

[0116]

[0117] Examples of luminescent materials that mainly involve luminescence function include, in addition to organic compounds represented by formula [1], fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetraphenylene derivatives, anthracene derivatives and rubrene), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organoaluminum complexes such as tris(8-hydroxyquinoline)aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and polymeric derivatives such as poly(phenylenevinylene) derivatives, poly(fluorene) derivatives and poly(phenylene) derivatives.

[0118] When the organic compound according to this embodiment is used to form a mixed layer with other luminescent materials, or when the luminescent layers are stacked, the other luminescent materials also appropriately have low HOMO / LUMO energy levels. This is because if the HOMO / LUMO energy levels are high, for example, in the case where other luminescent materials form excitocomplexes with the organic compound according to this embodiment, quenching components or trap levels may be formed.

[0119] The following are non-limiting specific examples of compounds used as luminescent materials.

[0120]

[0121] Examples of light-emitting layer host or light-emitting auxiliary materials included in the light-emitting layer include aromatic hydrocarbon compounds and their derivatives, carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organoaluminum complexes such as tris(8-hydroxyquinoline)aluminum, and organoberyllium complexes.

[0122] The host material is suitably formed from hydrocarbons and suitably has low HOMO / LUMO energy levels. This is because if the host material contains heteroatoms such as nitrogen atoms, the HOMO / LUMO energy levels are increased, and in cases where the host material forms an excitocomplex with an organic compound according to this embodiment, quenching components or trap energy levels may be formed.

[0123] In particular, the host material may have an anthracene, tetraphenyl, perylene, or pyrene skeleton in its molecular framework. This is because the host material is formed from hydrocarbons as described above and also has an S1 energy capable of inducing sufficient energy transfer to the organic compound according to this embodiment.

[0124] The following are non-limiting specific examples of compounds used as the host or auxiliary material for the luminescent layer contained in the luminescent layer.

[0125]

[0126] Electron-transporting materials can be freely selected from materials capable of transporting electrons injected from the cathode to the light-emitting layer. The selection of electron-transporting materials is considered, for example, in relation to the hole mobility of hole-transporting materials. Examples of materials with 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, etc.). (Derivatives and anthracene derivatives). The above electron transport materials are also suitable for hole blocking layers. The following are non-limiting specific examples of compounds used as electron transport materials.

[0127]

[0128] <Composition of Organic Light-Emitting Element>

[0129] Organic light-emitting elements are provided by forming an anode, an organic compound layer, and a cathode on a substrate. For example, a protective layer and a color filter can be disposed on the cathode. If a color filter is disposed, a planarization layer can be disposed between the protective layer and the color filter. The planarization layer can be formed from, for example, an acrylic resin.

[0130] [Substrate]

[0131] The substrate is formed from materials such as quartz, glass, silicon wafer, resin, or metal. Switching elements, such as transistors, and wiring can be disposed on the substrate, and an insulating layer can be disposed thereon. The insulating layer can be formed from any material, as long as it allows for the formation of contact holes to establish an electrical connection between the anode and the wiring, and insulates the anode from wiring where no anode is connected. Examples of materials used for the insulating layer include resins such as polyimide, silicon oxide, and silicon nitride.

[0132] [electrode]

[0133] An electrode can be a pair of electrodes. A pair of electrodes can be an anode and a cathode. When an electric field is applied along the direction of light emission from the organic light-emitting element, the electrode with the higher potential is the anode, and the other electrode is the cathode. Alternatively, the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0134] Materials used for anodes are expected to have the highest possible work function. Examples of materials for anodes include elemental 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 indium zinc oxide. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0135] These electrode materials can be used alone or in combination of two or more. The anode can have a single-layer or multi-layer structure.

[0136] When the anode is used as a reflective electrode, materials such as chromium, aluminum, silver, titanium, tungsten, molybdenum, their alloys, or laminates thereof can be used. When the anode is used as a transparent electrode, a transparent conductive oxide layer made of, for example, indium tin oxide (ITO) or indium zinc oxide can be used, but the material is not limited to these. The electrode can be formed by photolithography.

[0137] On the other hand, materials used for cathodes are expected to have low work functions. Examples of materials for cathodes include alkali metals such as lithium; alkaline earth metals such as calcium; elemental metals such as aluminum, titanium, manganese, silver, lead, and chromium; mixtures containing these metals; alloys of these metals, such as magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver; and metal oxides such as indium tin oxide (ITO). These electrode materials can be used alone or in combination of two or more. The cathode can have a single-layer or multi-layer structure. In particular, silver can be used, and silver alloys can also be used to suppress silver aggregation. Silver alloys can have any mixing ratio, such as 1:1, as long as silver aggregation is suppressed.

[0138] Any device can be used, such as a top-emitting device obtained by using an oxide conductive layer made of, for example, ITO as the cathode, or a bottom-emitting device obtained by using a reflective electrode made of, for example, aluminum (Al) as the cathode. There are no particular limitations on the method used to form the cathode. For example, DC sputtering and AC sputtering methods are appropriately used because good film coverage can be achieved, thereby easily reducing resistance.

[0139] <Protective Layer>

[0140] A protective layer can be formed on the cathode. For example, a glass plate containing a desiccant can be bonded to the cathode. This inhibits the penetration of water and the like into the organic compound layer, thus suppressing the occurrence of display defects. In another embodiment, a passivation film made of silicon nitride or the like can be formed on the cathode to inhibit the penetration of water and the like into the organic compound layer. For example, after the cathode is formed, the resulting substrate can be transferred to another chamber without breaking the vacuum, and a silicon nitride film with a thickness of 2 μm can be formed by chemical vapor deposition (CVD) to provide a protective layer. After the film is formed by CVD, the protective layer can be formed by atomic layer deposition (ALD).

[0141] <Color Filter>

[0142] Color filters can be disposed on the protective layer. For example, a color filter tailored to the size of the organic light-emitting element can be disposed on another substrate, and this substrate can be bonded to the substrate on which the organic light-emitting element is disposed. Optionally, the color filter can be patterned on the aforementioned protective layer using photolithography. The color filter can be formed from a polymer.

[0143] <Planning Layer>

[0144] A planarization layer can be placed between the color filter and the protective layer. The planarization layer can be formed of an organic compound. The organic compound can be a low molecular weight organic compound or a high molecular weight organic compound, but preferably a high molecular weight organic compound.

[0145] Planarization layers can be provided above and below the color filter, and the two planarization layers can be formed of the same or different materials. Specific examples of such materials include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, and urea resin.

[0146] <Opposing substrate>

[0147] A counter substrate can be disposed on the planarization layer. The name "counter substrate" derives from the fact that the counter substrate is disposed at a position corresponding to that of the aforementioned substrate. The counter substrate can be formed from the same material as the aforementioned substrate.

[0148] <Organic Compound Layer>

[0149] The organic compound layer (e.g., hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, and electron injection layer) constituting the organic light-emitting element according to an embodiment of the present invention is formed by the following methods.

[0150] The organic compound layer constituting the organic light-emitting element according to an embodiment of the invention can be formed by dry processes such as vacuum evaporation, ionization evaporation, sputtering, or plasma-based methods. Alternatively, a wet process can be used, in which the organic compound is dissolved in a suitable solvent and the layer is formed by a known coating method (e.g., spin coating, dip coating, casting, Langmuir-Blodgett (LB) coating, or inkjet coating).

[0151] When layers are formed using methods such as vacuum evaporation or solution coating, crystallization is less likely to occur, and the resulting layers exhibit high stability over time. When layers are formed using coating methods, layers can be formed by combining appropriate binder resins.

[0152] Non-limiting examples of adhesive resins include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, and urea resin.

[0153] These adhesive resins can be used alone as homopolymers or copolymers, or in combination as a mixture of two or more. Furthermore, known additives, such as plasticizers, antioxidants, and UV absorbers, can be optionally used in combination.

[0154] <Applications of organic light-emitting elements according to embodiments of the present invention>

[0155] The organic light-emitting element according to embodiments of the present invention can be used as a component of display devices and lighting devices. Additionally, the organic light-emitting element can be used as, for example, an exposure light source in an electrophotographic image forming apparatus, a backlight in a liquid crystal display device, and a light-emitting device including a white light source with a color filter.

[0156] The display device may be an image information processing device, comprising an image input unit that inputs image information from an area CCD, a linear CCD, or a memory card, and an information processing unit that processes the input information, and displays the input image on a display unit. The display device includes multiple pixels, and at least one of the multiple pixels may include an organic light-emitting element according to this embodiment and a transistor connected to the organic light-emitting element.

[0157] The display unit included in a camera device or inkjet printer may have touch panel functionality. The touch panel functionality can be driven by any method, such as using infrared light, electrostatic capacitance, resistive film, or electromagnetic induction. This display device can be used as the display unit of a multifunction printer.

[0158] Next, the display device according to this embodiment will be described with reference to the accompanying drawings. Figure 2 This is a schematic cross-sectional view illustrating an example of a display device including 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.

[0159] Figure 2 The display device 10 includes a substrate 11 made of glass or the like, and a moisture-proof film 12 disposed on the substrate 11 to protect TFT elements or organic compound layers. The display device 10 also includes a metal gate electrode 13, a gate insulating film 14, and a semiconductor layer 15.

[0160] Each TFT element 18 includes a semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is disposed on the TFT element 18. The anode 21 and the source electrode 17 constituting the organic light-emitting element 26 are connected to each other through a contact hole 20.

[0161] The electrical connection between the electrodes (anode 21 and cathode 23) included in the organic light-emitting element 26 and the electrodes (source electrode 17 and drain electrode 16) included in the TFT element 18 is not limited to the following. Figure 2 The form shown is sufficient. That is, 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.

[0162] exist Figure 2 In the display device 10, the organic compound layer 22 is shown as having a single-layer structure, but it may have a multi-layer structure. A first protective layer 24 and a second protective layer 25 are provided on the cathode 23 to suppress the degradation of the organic light-emitting element 26.

[0163] exist Figure 2 In the display device 10, transistors are used as switching elements. However, MIM elements can also be used as switching elements.

[0164] For Figure 2 The transistors in the display device 10 are not limited to transistors using monocrystalline silicon wafers, but can be thin-film transistors comprising an active layer on an insulating surface of a substrate. Examples of active layers include monocrystalline silicon, amorphous silicon, non-monocrystalline silicon such as microcrystalline silicon, and non-monocrystalline oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin-film transistors are also known as TFT elements.

[0165] Figure 2 The transistors included in the display device 10 can be formed within a substrate, such as a Si substrate. Here, the phrase "formed within a substrate" means that the transistors are manufactured by processing the substrate itself, such as a Si substrate. That is, transistors formed within a substrate can be considered as transistors integrally formed with the substrate.

[0166] In the organic light-emitting element according to this embodiment, the luminous intensity is controlled by a TFT, which serves as an example of a switching element. When multiple such organic light-emitting elements are arranged in a plane, an image can be displayed using the luminous intensity of each organic light-emitting element. The switching element according to this embodiment is not limited to a TFT. The switching element can be a transistor formed of low-temperature polysilicon or an active matrix driver formed on a substrate such as a Si substrate. The phrase "on the substrate" can also mean "within the substrate." The size of the display unit determines whether a transistor is arranged within the substrate or whether a TFT is used. For example, in the case of a size of about 0.5 inches, the organic light-emitting element can be arranged on a Si substrate.

[0167] Figure 3An example of a display device according to this embodiment is schematically shown. 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. Flexible printed circuits (FPCs) 1002 and 1004 are connected to the touch panel 1003 and the display panel 1005, respectively. Transistors are printed on the circuit board 1007. If the display device is not a mobile device, the battery 1008 does not need to be provided. Even if the display device is a mobile device, the battery 1008 can be provided in different locations.

[0168] The display device according to this embodiment can be used in the display unit of an optoelectronic conversion device, such as a camera device, which includes: an optical unit comprising a plurality of lenses and an imaging element configured to receive light passing through the optical unit. The camera device may include a display unit configured to display information obtained through the imaging element. The display unit may be an external display unit or a display unit disposed within a viewfinder. The camera device may be a digital camera or a digital video camera.

[0169] Figure 4A An example of a camera device according to this embodiment is schematically shown. The camera 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 can display not only the image to be captured, but also environmental information and camera instructions, etc. Environmental information may include, for example, the intensity of external light, the direction of external light, the speed of movement of the subject, and the possibility that the subject is obstructed by objects.

[0170] Because the window for capturing images is very short, it is desirable to display information as quickly as possible. Therefore, a display device incorporating an organic light-emitting element (OLED) according to this embodiment is appropriately used. This is because OLEDs have a high response time. A display device incorporating an OLED is more suitable than devices requiring high display speeds, such as liquid crystal displays.

[0171] The imaging device 1100 includes an optical unit (not shown). The optical unit includes multiple lenses and focuses an image onto an imaging element housed within a housing 1104. The focus can be adjusted by adjusting the relative positions of the multiple lenses. This operation can also be performed automatically.

[0172] The display device according to this embodiment may include a red color filter, a green color filter, and a blue color filter. The red, green, and blue color filters may be arranged in a triangular configuration.

[0173] The display device according to this embodiment can be used in the display unit of electronic devices such as mobile terminals. The display unit can have both display and operation functions. Examples of mobile terminals include mobile phones such as smartphones, tablet computers, and head-mounted displays.

[0174] Figure 4B An example of an electronic device according to this embodiment is schematically illustrated. The electronic device 1200 includes a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may include circuitry, a printed circuit board including the circuitry, a battery, and a communication unit. The operation unit 1202 may be a button or touch panel response unit. The operation unit may be a biometric authentication unit that unlocks the device via fingerprint recognition. The electronic device including the communication unit may be referred to as a communication device.

[0175] Figure 5A and Figure 5B An example of a display device according to this embodiment is shown schematically. Figure 5A A display device, such as a television monitor or a PC monitor, is shown. The display device 1300 includes a frame 1301 and a display unit 1302. A light-emitting device according to this embodiment can be used for the display unit 1302. The display device 1300 includes a frame 1301 and a base 1303 supporting the display unit 1302. The form of the base 1303 is not limited to... Figure 5A The frame 1301 can also be used as a base. Both the frame 1301 and the display unit 1302 can be curved. The radius of curvature can be greater than 5000 mm and less than 6000 mm.

[0176] Figure 5B Another example of a display device according to this embodiment is illustrated schematically. Figure 5B The display device 1310 is a so-called foldable display device. The display device 1310 includes 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 can constitute a single seamless display device. 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 can display different images, or the first display unit and the second display unit can be combined to display a single image.

[0177] Figure 6AAn example of a lighting device according to this embodiment is schematically shown. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, and an optical filter 1404 and a light diffusing unit 1405 for transmitting light emitted from the light source 1402. The light source 1402 may include an organic light-emitting element according to this embodiment. The optical filter 1404 may be a filter for improving the color rendering index of the light source. The light diffusing unit 1405 for lighting, etc., effectively diffuses the light from the light source and allows the light to reach a wide area. The optical filter 1404 and the light diffusing unit 1405 may be provided on the light-emitting side of the lighting device. Optionally, a cover may be provided on the outermost surface.

[0178] A lighting device is, for example, a device that illuminates a room. The lighting device may emit white, natural white, or any other color of light from blue to red. The lighting device may include a light modulation circuit configured to modulate light. The lighting device may include an organic light-emitting element according to this embodiment and a power supply circuit connected to the organic light-emitting element. The power supply circuit is a circuit that converts alternating current (AC) voltage to direct current (DC) voltage. The color "white" has a color temperature of 4200K, and the color "natural white" has a color temperature of 5000K. The lighting device may include a color filter.

[0179] The lighting device according to this embodiment may include a heat dissipation unit. The heat dissipation unit dissipates heat from inside the device to the outside and is formed of, for example, a metal or liquid silicon with a high specific heat.

[0180] Figure 6B A car is schematically shown as an example of a moving object according to this embodiment. The car includes a taillight as an example of a lighting device. The car 1500 includes a taillight 1501, and the taillight can be illuminated by, for example, the operation of a brake.

[0181] The taillight 1501 may include an organic light-emitting element according to this embodiment. The taillight 1501 may include a protective member protecting the organic light-emitting element. The protective member may be made of any material, provided it has relatively high strength and transparency. The protective member may be made of polycarbonate or the like. Polycarbonate may be mixed with, for example, furan dicarboxylic acid derivatives or acrylonitrile derivatives.

[0182] The vehicle 1500 may include a body 1503 and a window 1502 attached to the body 1503. The window 1502 may be a transparent display, provided that the window 1502 is not used for inspecting the front and rear of the vehicle. The transparent display may include an organic light-emitting element according to this embodiment. In this case, components such as electrodes included in the organic light-emitting element are formed of a transparent material.

[0183] The moving object according to this embodiment can be, for example, a ship, aircraft, or drone. The moving object may include a body and lighting fixtures mounted on the body. The lighting fixtures can emit light to make the position of the body identifiable. The lighting fixtures may include organic light-emitting elements according to this embodiment.

[0184] Figure 7 An example of an image forming apparatus according to this embodiment is schematically shown. The image forming apparatus 40 is an electrophotographic image forming apparatus and includes a photosensitive element 27, an exposure light source 28, a developing unit 30, a charging 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 photosensitive element 27. The exposure light source 28 includes an organic light-emitting element according to this embodiment. The developing unit 30 includes, for example, a toner. The charging unit 31 is configured to charge the photosensitive element 27. The transfer unit 32 is configured to transfer the developed image onto a recording medium 34. The transport roller 33 is configured to transport the recording medium 34. The recording medium 34 is, for example, paper. The fixing unit 35 is configured to fix the image formed on the recording medium 34.

[0185] Figure 8A and Figure 8B An exposure light source 28 in which multiple light-emitting units 36 are arranged on an elongated substrate is schematically shown. Arrow 37 indicates the row direction in which the organic light-emitting elements are arranged. This row direction is the same as the direction of the axis around which the photosensitive member 27 rotates. This direction can also be referred to as the long axis direction of the photosensitive member 27. Figure 8A The diagram shows the configuration of the light-emitting unit 36 ​​along the long axis of the photosensitive member 27. Figure 8B The diagram shows the state in which the light-emitting units 36 are alternately arranged along the row direction in each of the first and second rows, which is consistent with... Figure 8A The states in the columns are different. In the first and second rows, the light-emitting units 36 are arranged at different positions along the column direction. In the first row, multiple light-emitting units 36 are arranged at intervals between each other. In the second row, the light-emitting units 36 are arranged at positions corresponding to the intervals between the light-emitting units 36 in the first row. In other words, multiple light-emitting units 36 are also arranged at intervals between each other along the column direction. Figure 8B The configuration in the text can also be referred to as, for example, grid configuration, staggered configuration, or staggered grid configuration.

[0186] As described above, using a device that includes an organic light-emitting element according to this embodiment enables stable display with good image quality over a long period of time.

[0187] Example

[0188] The invention will be described below based on embodiments. However, the invention is not limited thereto.

[0189] <Example 1 (Synthesis of Exemplary Compound A1)>

[0190]

[0191] (1) Synthesis of compound E3

[0192] Place the following reagents and solvents into a 200ml round-bottom flask.

[0193] Compound E1: 1.82 g (10 mmol)

[0194] Compound E2: 3.10 g (10 mmol)

[0195] Ethanol: 100ml

[0196] The reaction solution was then heated to 70°C under a nitrogen atmosphere, and a KOH ethanol solution was added dropwise. The mixture was stirred at this temperature (70°C) for 6 hours. After the reaction was complete, water was added, and the resulting precipitate was separated. The separated product was washed with methanol to give 3.42 g of a dark gray compound E3 (yield: 75%).

[0197] (2) Synthesis of compound E5

[0198] Place the following reagents and solvents into a 100ml round-bottom flask.

[0199] Compound E3: 3.19 g (7 mmol)

[0200] Compound E4: 2.25g (9mmol)

[0201] Amyl nitrite: 1.05g (9mmol)

[0202] Toluene: 40ml

[0203] The reaction solution was then heated to 110°C under a nitrogen atmosphere and stirred at this temperature (110°C) for 3 hours. After the reaction was complete, the solution was washed twice with 40 ml of water. The organic layer was washed with a saturated salt solution and dried over magnesium sulfate. The resulting solution was then separated, and the filtrate was concentrated to obtain a brown liquid. This liquid was purified by column chromatography (chloroform / heptane = 1:4) and then recrystallized from chloroform / methanol to give 3.67 g of yellow crystalline compound E5 (yield: 85%).

[0204] (3) Synthesis of compound E7

[0205] Place the following reagents and solvents into a 200ml round-bottom flask.

[0206] Compound E5: 1.85g (3mmol)

[0207] Compound E6: 0.51g (3mmol)

[0208] Pd(PPh3)4: 0.06g

[0209] Toluene: 50ml

[0210] Ethanol: 20ml

[0211] 2M sodium carbonate aqueous solution: 50ml

[0212] The reaction solution was then heated to 80°C under a nitrogen stream and stirred at that temperature (80°C) for 6 hours. After the reaction was complete, water was added and the mixture was separated. The resulting product was dissolved in chloroform, purified by column chromatography (chloroform), and then recrystallized from chloroform / methanol to give 1.49 g of yellow crystalline compound E7 (yield: 75%).

[0213] (4) Synthesis of exemplary compound A1

[0214] Place the following reagents and solvents into a 20ml round-bottom flask.

[0215] Compound E7: 665 mg (1 mmol)

[0216] Pd(dba)2: 58mg

[0217] P(Cy)3 (tricyclohexylphosphine): 84mg

[0218] Potassium acetate: 196mg

[0219] DMF: 10ml

[0220] The reaction solution was then heated to 145°C under a nitrogen atmosphere and stirred at this temperature (145°C) for 6 hours. After the reaction was complete, ethanol was added to precipitate crystals. The crystals were separated and washed successively with water, ethanol, and heptane. The resulting purple crystals were then dissolved in toluene by heating, followed by hot filtration and recrystallization from toluene / methanol to obtain 0.48 g of the yellow exemplary compound A1 (yield: 78%).

[0221] As confirmed by HPLC, the purity of the compound is above 99%.

[0222] The exemplary compound A1 was analyzed by mass spectrometry using MALDI-TOF-MS (Autoflex LRF manufactured by Bruker).

[0223] MALDI-TOF-MS

[0224] Measured value: m / z = 628.85, Calculated value: C 46 H 20 N4 = 628.69

[0225] <Example 2 (Synthesis of Exemplary Compound A7)>

[0226] Exemplary compound A7 was obtained by the same method as in Example 1, except that compound E8 was used instead of compound E2 and compound E9 was used instead of compound E6.

[0227]

[0228] The purity of the obtained compound was evaluated by HPLC. The purity was above 98%.

[0229] In addition, the compound was analyzed by mass spectrometry using MALDI-TOF-MS (Autoflex LRF manufactured by Bruker).

[0230] MALDI-TOF-MS

[0231] Measured value: m / z = 678.43, Calculated value: C 50 H 22 N4 = 678.75

[0232] <Example 3 (Synthesis of Exemplary Compound B5)>

[0233] Exemplary compound B5 was obtained by the same method as in Example 1, except that compound E10 was used instead of compound E1, compound E11 was used instead of compound E4, and compound E12 was used instead of compound E6.

[0234]

[0235] The purity of the obtained compound was evaluated by HPLC. The purity was above 98%.

[0236] In addition, the compound was analyzed by mass spectrometry using MALDI-TOF-MS (Autoflex LRF manufactured by Bruker).

[0237] MALDI-TOF-MS

[0238] Measured value: m / z = 628.02, Calculated value: C 46 H 20 N4 = 628.69

[0239] <Example 4 (Synthesis of Exemplary Compound C13)>

[0240] Exemplary compound C13 was obtained by the same method as in Example 1, except that compound E13 was used instead of compound E1, compound E14 was used instead of compound E2, and compound E15 was used instead of compound E6.

[0241]

[0242] The purity of the obtained compound was evaluated by HPLC. The purity was above 98%.

[0243] In addition, the compound was analyzed by mass spectrometry using MALDI-TOF-MS (Autoflex LRF manufactured by Bruker).

[0244] MALDI-TOF-MS

[0245] Measured value: m / z = 848.22, Calculated value: C 62 H 28 F4 = 848.90

[0246] <Comparative Example 1 (Comparative Synthesis of Compound (9))>

[0247] Except that compound E16 was used instead of compound E14, the following comparative compounds (9) were obtained by the same method as in Example 4.

[0248]

[0249] Exemplary compound C13 and comparative compound (9) have the same basic skeleton consisting of ring A and the same substituents consisting of ring B, but differ in the presence or absence of the electron-withdrawing group Q. To evaluate the sublimability of these compounds, the difference between the decomposition temperature and the sublimation temperature was determined. The temperature difference for comparative compound (9) was 10°C, while the temperature difference for exemplary compound C13 was 100°C. Because of the large difference between the decomposition temperature and the sublimation temperature of exemplary compound C13, it exhibits a large temperature margin during sublimation purification and therefore high sublimability.

[0250] <Example 5 (Synthesis of Exemplary Compound A20)>

[0251]

[0252] (1) Synthesis of compound E19

[0253] Place the following reagents and solvents into a 1000ml round-bottom flask.

[0254] Compound E17: 4.55g (10mmol)

[0255] Compound E18: 3.78 g (22 mmol)

[0256] Pd(PPh3)4: 0.1g

[0257] Toluene: 250ml

[0258] Ethanol: 120ml

[0259] 2M sodium carbonate aqueous solution: 120ml

[0260] The reaction solution was then heated to 80°C under a nitrogen stream and stirred at that temperature (80°C) for 6 hours. After the reaction was complete, water was added and the mixture was separated. The resulting product was dissolved in chloroform, purified by column chromatography (chloroform), and then recrystallized from chloroform / methanol to give 4.12 g of pale yellow crystalline compound E19 (yield: 75%).

[0261] (2) Synthesis of compound E20

[0262] Place the following reagents and solvents into a 500ml round-bottom flask.

[0263] Compound E19: 3.84 g (7 mmol)

[0264] Bis(pinacolborane): 4.05g (16mmol)

[0265] Pd(dba)2: 402mg

[0266] P(Cy)3 (tricyclohexylphosphine): 588mg

[0267] Toluene: 20ml

[0268] The reaction solution was then heated to 110°C under a nitrogen stream and stirred at this temperature (110°C) for 3 hours. After the reaction was complete, the solution was washed twice with 40 ml of water. The organic layer was washed with a saturated salt solution and dried over magnesium sulfate. The resulting solution was then separated, and the filtrate was concentrated to obtain a brown liquid. This liquid was purified by column chromatography (toluene) and then washed with heptane dispersion to give 4.35 g of a brownish-white solid E20 (yield: 85%).

[0269] (3) Synthesis of exemplary compound A20

[0270] Place the following reagents and solvents into a 20ml round-bottom flask.

[0271] Compound E20: 732 mg (1 mmol)

[0272] Compound E21: 760 mg (2 mmol)

[0273] Pd(dba)2: 58mg

[0274] P(Cy)3 (tricyclohexylphosphine): 84mg

[0275] Potassium acetate: 196mg

[0276] DMF: 10ml

[0277] The reaction solution was then heated to 145°C under a nitrogen atmosphere and stirred at this temperature (145°C) for 6 hours. After the reaction was complete, ethanol was added to induce crystal precipitation. The crystals were then separated and washed sequentially with water, ethanol, and heptane. The resulting purple crystals were then dissolved in toluene by heating, followed by hot filtration and recrystallization from toluene / methanol to obtain 0.44 g of the yellow exemplary compound A20 (yield: 60%).

[0278] As confirmed by HPLC, the purity of the compound is above 99%.

[0279] The exemplary compound A20 was analyzed by mass spectrometry using MALDI-TOF-MS (Autoflex LRF manufactured by Bruker).

[0280] MALDI-TOF-MS

[0281] Measured value: m / z = 728.85, Calculated value: C 54 H 24 N4 = 728.81

[0282] <Comparative Example 2 (Synthesis of Comparative Compound (10))>

[0283] Except that compound E21 was used instead of compound E18, the following comparative compound (10) was obtained by the same method as in Example 5.

[0284]

[0285] Exemplary compound A20 and comparative compound (10) have the same basic skeleton consisting of ring A and the same substituents consisting of ring B, but differ in the presence or absence of the electron-withdrawing group Q. To evaluate the oxidation potential of these compounds, CV measurements were performed. The oxidation potential of comparative compound (10) was 1.05 V, while the oxidation potential of exemplary compound A20 was 1.13 V. This indicates that exemplary compound A20 is a compound with higher oxidation stability.

[0286] <Example 6>

[0287] In this embodiment, a bottom-emitting organic EL element is produced, wherein 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 are sequentially formed on a substrate.

[0288] First, ITO is deposited on a glass substrate and patterned as desired to form an ITO electrode (anode). The thickness of the ITO electrode is set to 100 nm. In the following processes, this substrate with the ITO electrode formed thereon is used as the ITO substrate. Subsequently, the ITO electrode is deposited on a 1.33 × 10⁻⁶ nm thick substrate. -4 Vacuum deposition is performed in a vacuum chamber using resistance heating to sequentially form the organic EL layer and electrode layer shown in Table 4 on the ITO substrate. At this time, the electrode area of ​​the counter electrode (metal electrode layer, cathode) is set to 3 mm². 2 .

[0289] Table 4

[0290]

[0291] The characteristics of the obtained element were measured and evaluated. The external quantum efficiency (EQE) was 5.8%. The maximum emission wavelength of the light-emitting element was 453 nm, and it emitted blue light with a chromaticity of (X,Y)=(0.15,0.17). Regarding the measurement methods, specifically, the current-voltage characteristics were measured using a microammeter 4140B manufactured by Hewlett-Packard Company, and the luminous intensity was measured using a BM7 manufactured by TOPCON Corporation. Furthermore, a current density of 100 mA / cm² was used. 2 A continuous drive test was conducted to measure the time (LT90) taken for the brightness degradation rate to reach 10%. This time exceeded 100 hours. Table 5 shows the measurement results.

[0292] <Examples 7 to 14 and Comparative Examples 3 and 4>

[0293] Organic light-emitting elements were produced using the same method as in Example 6, except that the compounds were appropriately modified to those listed in Table 5. The properties of the resulting elements were measured and evaluated in the same manner as in Example 6. Table 5 shows the measurement results.

[0294] Table 5

[0295]

[0296] Table 5 shows that the organic light-emitting element containing comparative compound (1) emits sky blue light with a chromaticity of (X,Y) = (0.18,0.32). This is because the guest compound (1) has a long emission wavelength. In the organic light-emitting element containing comparative compound (10), the time taken to reach a 10% brightness degradation rate is 70 hours. This is because the guest compound (10) has a low oxidation potential. In contrast, the element containing the organic compound according to an embodiment of the present invention has good blue light emission characteristics and high durability.

[0297] <Example 15>

[0298] In this embodiment, a top-emitting organic EL element is produced, wherein an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a first light-emitting layer, a second light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode are sequentially formed on a substrate.

[0299] A 40 nm thick Ti film was formed on a glass substrate by sputtering, and then patterned using photolithography to form the anode. The electrode area of ​​the counter electrode (metal electrode layer, cathode) was set to 3 mm². 2 Subsequently, the cleaned substrate with electrodes formed on it and the material are placed in a vacuum evaporation system (manufactured by ULVAC, Inc.), and the system is evacuated to a pressure of 1.33 × 10⁻⁶. -4 Pa(1×10 -6 Torr), followed by UV / ozone cleaning. Subsequently, the layers shown in Table 6 are formed. Finally, sealing is performed in a nitrogen atmosphere.

[0300] Table 6

[0301]

[0302] The characteristics of the obtained component were measured and evaluated. The obtained component exhibited good white light emission. Furthermore, an initial luminance of 2000 cd / m² was measured. 2 A continuous drive test was conducted to measure the brightness degradation rate after 100 hours. The brightness degradation rate was 12%.

[0303] <Examples 16 to 24 and Comparative Example 5>

[0304] Organic light-emitting elements were produced using the same method as in Example 15, except that the compounds were appropriately modified to those listed in Table 7. The properties of the resulting elements were measured and evaluated in the same manner as in Example 15. Table 7 shows the measurement results.

[0305] Table 7

[0306]

[0307] Table 7 shows that the brightness degradation rate of the organic light-emitting element containing the comparative compound (9) is 30%. This is because the guest is the comparative compound (9), which has low sublimation properties.

[0308] The organic compound according to embodiments of the present invention has a high oxidation potential and high chemical stability. This organic compound also exhibits high sublimation properties. Therefore, by using this organic compound, an organic light-emitting element with high driving durability can be provided.

[0309] While the invention has been described with reference to exemplary embodiments, it should be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims is to be accorded the broadest interpretation, thereby covering all such modifications and equivalent structures and functions.

Claims

1. An organic compound, characterized in that, It is represented by the following general formula [1], [1] Wherein, ring A is FF12 or FF14, and optionally has a fluorine atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 18 carbon atoms, or a silyl group as a substituent. The condition is that when the alkyl or aryl group has a substituent, the substituent is a fluorine atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 18 carbon atoms, or a silyl group. Ring B1 and ring B2 are aromatic hydrocarbon rings with 6 to 18 carbon atoms, and each has more than two electron-withdrawing groups. At least one of the two or more electron-withdrawing groups is a cyano group, and Q1 and Q2 represent an electron-withdrawing group of ring B1 and an electron-withdrawing group of ring B2, respectively, and Q1 and Q2 are located at adjacent positions of ring B1 and ring B2 relative to ring A, respectively.

2. The organic compound according to claim 1, in, The ring A has a fluoranthene skeleton represented by the following general formula [2], and The rings B1 and B2 in the general formula [2] Any point in the position is associated with ring A. 。 3. The organic compound according to claim 1, wherein ring B1 and ring B2 have the same structure, and Q1 and Q2 represent the same electron-withdrawing groups.

4. The organic compound according to claim 1, wherein Q1 and Q2 represent cyano groups.

5. The organic compound according to claim 1, wherein ring B1 and ring B2 are either benzene rings or naphthalene rings.

6. An organic light-emitting element, comprising: anode; cathode; and An organic compound layer disposed between the anode and the cathode, Characterized by the fact that at least one of the organic compound layers comprises the organic compound according to claim 1, and The layer containing the organic compound is a light-emitting layer.

7. The organic light-emitting element according to claim 6, in, The organic compound layer further includes other light-emitting layers configured together with the light-emitting layer to form a multilayer structure, and The other light-emitting layers emit light of a different color than the light emitted from the light-emitting layers.

8. The organic light-emitting element according to claim 7, wherein the organic light-emitting element emits white light.

9. A display device comprising a plurality of pixels, Its features are, At least one of the plurality of pixels includes an organic light-emitting element according to any one of claims 6 to 8 and a transistor connected to the organic light-emitting element.

10. A photoelectric conversion device, comprising: An optical unit comprising multiple lenses; An imaging element that receives light passing through the optical unit; and A display unit that displays images captured by the camera element. The display unit is characterized in that it comprises an organic light-emitting element according to any one of claims 6 to 8.

11. An electronic device, characterized in that, It includes: A display unit comprising an organic light-emitting element according to any one of claims 6 to 8; A housing, in which the display unit is disposed; and A communication unit housed within the housing and communicating with the outside.

12. A lighting device, characterized in that, It includes: A light source comprising an organic light-emitting element according to any one of claims 6 to 8; and A light diffuser unit or optical filter that allows light emitted from the light source to pass through.

13. A movable object, characterized in that, It includes: Lighting appliances comprising organic light-emitting elements according to any one of claims 6 to 8; and The body, on which the lighting fixture is provided.

14. An exposure light source for an electrophotographic image forming apparatus, characterized in that, It includes an organic light-emitting element according to any one of claims 6 to 8.

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