Organic compound and organic light-emitting element

Abstract

To provide an organic light-emitting element with high durability.SOLUTION: An organic compound in which an indolocarbazole ring and a xanthone ring are bonded through a benzene ring, a dibenzothiophene ring, or a xanthone ring is used as a host of a light-emitting layer.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] An organic light-emitting device (also referred to as an organic electroluminescence device or an organic EL device) is an electronic device having a pair of electrodes and an organic compound layer disposed between these electrodes. By injecting electrons and holes from these pair of electrodes, excitons of a light-emitting organic compound in the organic compound layer are generated, and when the excitons return to the ground state, the organic light-emitting device emits light. Recent progress in organic light-emitting devices is remarkable, including low driving voltage, various emission wavelengths, high-speed responsiveness, and the ability to make the light-emitting device thinner and lighter. By the way, the creation of compounds suitable for organic light-emitting devices has been actively carried out up to now. This is because in providing high-performance organic light-emitting devices, the creation of compounds with excellent device lifetime characteristics is important. As compounds created so far, indolocarbazole derivative 1-a is described in Patent Document 1 and 1-b is described in Patent Document 2.

[0003]

Chemical Formula

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, Patent Documents 1 and 2 each disclose an organic compound for use in an organic light-emitting device having excellent element lifetime characteristics. However, in an organic light-emitting device, further improvement in durability characteristics is desired. The present invention has been made in view of the above problems, and an object thereof is to provide an organic light-emitting device having excellent durability characteristics. Means for Solving the Problems

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

[0007]

Chemical formula

[0008]

Chemical formula

Advantages of the Invention

[0009] By using the organic compound according to the present invention in a phosphorescent light-emitting layer, a light-emitting device with high efficiency and long life can be obtained.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described. It is easily understood by those skilled in the art that the present invention is not limited to the following description, and various changes can be made to its form and details without departing from the gist and scope of the present invention. That is, the present invention should not be construed as being limited by the following description.

[0012] 〔Organic Compound〕 First, the organic compound according to this embodiment will be described. The organic compound of the present invention is a compound represented by the following general formula [1].

[0013]

Chemical Formula

[0014] In the above general formula [1], p, m, and n are each independently 0 or 1, and p + m + n ≧ 1, L 1 is a divalent substituent derived from any of a substituted or unsubstituted biphenyl, terphenyl, dibenzothiophene, or a combination of q benzenes, r dibenzothiophenes, and s xanthones, where q, r, and s are each independently an integer of 0 or 1 or more, and q + r + s ≧ 2, L 2 is a monovalent or divalent substituent derived from any of a substituted or unsubstituted benzene, biphenyl, terphenyl, dibenzothiophene, or a combination of q benzenes, r dibenzothiophenes, and s xanthones, where q, r, and s are each independently an integer of 0 or 1 or more, and q + r + s ≧ 2, HAr 1 and HAr 2Each is independently represented by any one of the following general formulas [2-1] to [2-3].

[0015]

Chemical formula

[0016] In the above general formulas [2-1] to [2-3], R 10 to R 40 are selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, and a substituted or unsubstituted silyl group.

[0017] R 10 to R 40 For the halogen atom, alkyl group, alkoxy group, and silyl group exemplified as R

[0018] Examples of the halogen atom include, but are not limited to, fluorine, chlorine, bromine, iodine, astatine, tennessine, etc.

[0019] Examples of the alkyl group include an alkyl group having 1 to 20 carbon atoms. For example, methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, tert-butyl group, sec-butyl group, octyl group, cyclohexyl group, tert-pentyl group, 3-methylpentan-3-yl group, 1-adamantyl group, 2-adamantyl group, etc., but are not limited to these.

[0020] Examples of the alkoxy group include an alkoxy group having 1 to 10 carbon atoms. For example, methoxy group, ethoxy group, propoxy group, isopropoxy group, tert-butoxy group, 2-ethyl-octyloxy group, benzyloxy group, etc., but are not limited to these.

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

[0022] Also, L in the general formula [1] above 1 , L 2 , and R in the general formulas [2-1] to [2-3] above 10 to R 40 Examples of the substituent that may be possessed include a halogen atom, an alkyl group, an alkoxy group, an aryl group, a heterocyclic group, an amino group, and a silyl group.

[0023] Examples of the halogen atom include, for example, fluorine, chlorine, bromine, iodine, astatine, tennessine, etc., but are not limited thereto.

[0024] Examples of the alkyl group include an alkyl group having 1 to 20 carbon atoms. For example, methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, tert-butyl group, sec-butyl group, octyl group, cyclohexyl group, tert-pentyl group, 3-methylpentan-3-yl group, 1-adamantyl group, 2-adamantyl group, etc. are included, but are not limited thereto.

[0025] Examples of the alkoxy group include an alkoxy group having 1 to 10 carbon atoms. For example, methoxy group, ethoxy group, propoxy group, isopropoxy group, tert-butoxy group, 2-ethyl-octyloxy group, benzyloxy group, etc. are included, but are not limited thereto.

[0026] Examples of the aryl group include an aryl group having 6 to 20 carbon atoms. For example, phenyl group, naphthyl group, indenyl group, biphenyl group, terphenyl group, fluorenyl group, phenanthryl group, triphenylenyl group, pyrenyl group, anthranyl group, perylenyl group, chrysenyl group, fluoranthenyl group, etc. are included, but are not limited thereto.

[0027] Examples of the heterocyclic group include heteroaryl groups having 3 to 20 carbon atoms. For example, pyridyl group, pyrimidyl group, pyrazyl group, triazolyl group, benzofuranyl group, benzothiophenyl group, dibenzofuranyl group, dibenzothiophenyl group, oxazolyl group, oxadiazolyl group, thiazolyl group, thiadiazolyl group, carbazolyl group, acridinyl group, phenanthrolyl group, etc. are included, but not limited thereto.

[0028] Examples of the silyl group include, but are not limited to, trimethylsilyl group, triphenylsilyl group, etc.

[0029] Examples of the amino group include, but are not limited to, N-methylamino group, N-ethylamino group, N,N-dimethylamino group, N,N-diethylamino group, N-methyl-N-ethylamino group, N-benzylamino group, N-methyl-N-benzylamino group, N,N-dibenzylamino group, anilino group, N,N-diphenylamino group, N,N-dinaphthylamino group, N,N-difluorenylamino group, N-phenyl-N-tolylamino group, N,N-ditolylamino group, N-methyl-N-phenylamino group, N,N-dianisorylamino group, N-mesityl-N-phenylamino group, N,N-dimesitylamino group, N-phenyl-N-(4-tert-butylphenyl)amino group, N-phenyl-N-(4-trifluoromethylphenyl)amino group, N-piperidyl group, carbazolyl group, acridinyl group, trimethylamino group, triphenylamino group, etc.

[0030] Examples of the substituents that the above alkyl group, alkoxy group, amino group, aryl group, heterocyclic group, aryloxy group, and silyl group may further have include, but are not limited to, deuterium, alkyl groups such as methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, and tert-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.

[0031] L in General Formula [1] 1 preferably has one or more substituted or unsubstituted dibenzothiophenes, or two or more substituted or unsubstituted xanthones.

[0032] Also, L in General Formula [1] 2 is preferably represented by any of the following General Formulas [3-1] to [3-5].

[0033] [Chemical formula] In the above General Formulas [3-1] to [3-5], * indicates the bonding position.

[0034] The organic compound of the present invention has the following characteristics. (1-1) By having a hole-transporting indolocarbazole ring and an electron-transporting xanthone ring in the molecule, charge and energy accumulation are improved, and the durability characteristics are excellent. (1-2) All rotatable bonds are composed of sp 2 carbons, resulting in high bond energy and improved device durability. (1-3) The hole-transporting indolocarbazole ring and the electron-transporting xanthone ring are directly or through a spacer L with a specific structure 1 , L 2Since it is connected by [reference], it has excellent stability. Hereinafter, these features will be described.

[0035] (1-1) By having an indolocarbazole ring with high hole transportability and high T1 and binding stability in the molecule, and a xanthone ring with high electron transportability and high T1 and binding stability, the charge and energy accumulation are improved, and the durability characteristics are excellent. In inventing the organic compound represented by the general formula [1], the present inventors focused on the hole transport unit, electron transport unit, and permanent dipole moment of the molecule. The compound in the organic compound layer of the organic light-emitting device, particularly in the light-emitting layer, repeatedly transitions between the ground state and the excited state during the light-emitting process of the organic light-emitting device. In particular, in the organic light-emitting device with phosphorescent emission, it is important to control the triplet excited state (T1) that occupies 75% of the excited state. For example, it is necessary to efficiently promote energy transfer from the T1 of the host molecule to the guest molecule and efficiently emit light from the guest molecule. If the energy transfer efficiency is poor, the probability that the generated excitation energy is used for the reaction with adjacent molecules increases, causing deterioration of the durability characteristics due to the generation of quencher molecules. The energy transfer process from the T1 of the host molecule to the guest molecule is known to occur by Dexter energy transfer. In order to improve the efficiency of Dexter energy transfer, it is important to make the distance between the host molecule and the guest molecule as close as possible.

[0036] As a result of intensive studies, the present inventors have found that it is effective to have one xanthene ring and at least one indolocarbazole ring in order to reduce the intermolecular distance between the host molecule and the guest molecule. This is characterized in that by arranging both the xanthene ring and the indolocarbazole ring, which preferably interact with the metal atom (e.g., iridium atom) of the guest molecule, within the molecule at the same time, the intermolecular interaction with the guest molecule increases and the intermolecular distance decreases. Further, from another perspective, since the xanthene ring and the indolocarbazole ring have different heteroatoms in the skeleton, they are characterized by increased polarization. Table 1 shows the dipole moments of two organic compounds of the present invention and an organic compound (comparative compound) outside the scope of the present invention. As shown in Table 1, the organic compounds of the present invention are characterized by an increased permanent dipole moment. Furthermore, a host molecule having a large permanent dipole moment is preferable because it is also compatible with highly polar guest molecules such as Ir complexes and Pt complexes.

[0037]

Table 1

[0038] (1-2) All rotatable bonds are sp 2 Consisting of carbon results in high bond energy and improved device durability. In the organic compound layer of an organic light-emitting device, particularly the compound in the light-emitting layer, repeatedly transitions between the ground state and the excited state during the light-emitting process of the organic light-emitting device. During this process, intense molecular stretching, rotation, and other movements occur. At this time, if there is a site where the bond is easily dissociated, the bond may cleave and a part of the compound may be released. When a part of the compound is released, the structure changes, so the durability of the compound is low because release is likely to occur. Further, when such a compound is used in an organic light-emitting device, the released portion becomes a quencher and reduces the device durability. Therefore, a molecule having a structure in which the bond is difficult to dissociate and release is less likely to occur has better durability. In the organic compound of the present invention, all rotatable bonds are sp 2Since it is made of carbon, dissociation due to bond cleavage is less likely to occur, and the durability is high. Therefore, when the organic compound of the present invention is used in the organic compound layer of an organic light-emitting device, dissociation due to bond cleavage during device driving is less likely to occur. Thus, even when driven for a long time, device degradation is suppressed, and an organic light-emitting device with excellent durability can be obtained.

[0039] (1-3) The hole-transporting indolocarbazole ring and the electron-transporting xanthone ring are directly connected, or connected by a spacer L with a specific structure 1 , L 2 Therefore, the above two are excellent in stability. It is generally known that a compound having a structure in which a hole-transporting unit and an electron-transporting unit are combined transfers charges through the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital). In that case, regarding the linking group connecting the two units, a structure that is strong against charges is more preferable. Also, when directly bonding without a linking group, since there is no rotatable site, it is strong against charges and excellent in stability. Examples of structures that are strong against charges include a benzene ring and a dibenzothiophene ring. Here, regarding the dibenzofuran ring having a structure similar to the dibenzothiophene ring, there is a part that is weak against charges, and it is said to have low repetitive stability against oxidation-reduction. Also, when considering the dibenzothiophene ring and the dibenzofuran ring in light of the HSAB principle, the dibenzothiophene ring preferably interacts with the metal atom (for example, iridium atom) of the guest molecule. According to the HSAB principle, a soft acid easily binds to a soft base, and a hard acid easily binds to a hard base. The general characteristics of soft acid-base are that the central atom is large, the electronegativity is small, the polarizability is large, and it has a low charge density, while hard acid-base has the opposite properties. Therefore, when comparing the dibenzothiophene ring and the dibenzofuran ring, the dibenzothiophene ring is soft and the dibenzofuran ring is classified as hard. The iridium complex used as the guest molecule has a large metal element at the center and is classified as soft, so it has better compatibility with the dibenzothiophene ring.

[0040] In terms of molecular structure, as shown in Table 2, the degree of structural distortion is different between the dibenzothiophene ring and the dibenzofuran ring. The angles a and b shown in Table 2 are bonds formed by the sp 2 hybrid orbitals of carbon atoms, so an angle closer to 120° is a more natural angle. From the values in Table 2, since the dibenzofuran ring has a more distorted structure, its stability is low. Therefore, as the molecular structure, it is more preferable to use the dibenzothiophene ring.

[0041] [Table 2]

[0042] Furthermore, it is preferable that the organic compound of the present invention has the following characteristics. (1-4) Since the bonding position of the indolocarbazole ring is the meta-position of the nitrogen atom, a high T1 can be maintained, so the device efficiency and device durability are improved. (1-5) L 1 is possessed, and the L 1 has a molecular weight of a biphenylene group or a dibenzothiophenylene group or more, so it has excellent film stability. Hereinafter, these characteristics will be described.

[0043] (1-4) Since the bonding position of the indolocarbazole ring is the meta-position of the nitrogen atom, a high singlet excited state (S1) can be maintained, so the device efficiency and device durability are improved. The organic compound of the present invention has a structure having an indolocarbazole ring, and the bond with the spacer L 1 is not a para-position or ortho-position bond of the nitrogen atom, but a meta-position bond. Due to the meta-position bond, S1 does not become lower than that of the para-position bond or ortho-position bond, and a high state can be maintained. Furthermore, the bond is less distorted than the ortho-position bond. Therefore, the spacer L of the indolocarbazole ring 1The bonding position with respect to the nitrogen atom is preferably a meta-bond. For example, as shown in Table 3, the organic compound of the present invention having a meta-bond in the indolocarbazole ring has a higher S1 than Comparative Compound 1-a and Comparative Compound 1-c. Since a high S1 results in a high energy transfer efficiency to the guest molecule, the device efficiency is improved, and the device durability is also improved because the exciton lifetime is shortened. In addition, the dihedral angle between the indolocarbazole ring and the dibenzothiophene ring is 63.4° for the ortho-bonded Comparative Compound 1-c and 38.5° for the organic compound of the present invention, indicating greater planarity. Therefore, since the overlap between molecules is also large, it is preferable because the energy transfer efficiency to the guest molecule is higher.

[0044]

Table 3

[0045] (1-5)L 1 has, and the L1 has a molecular weight of a biphenylene group or a dibenzothiophenylene group or more, so that it has excellent film stability. Materials used in the organic layer of an organic light-emitting device are generally preferably those having a higher glass transition temperature (Tg). It is known that the glass transition temperature generally tends to increase as the molecular weight increases. Therefore, a biphenylene group or a terphenylene group is more preferable than a phenylene group in terms of the glass transition temperature. Furthermore, as the molecular weight increases, the state of the film becomes a more stable film, which is more preferable.

[0046] Furthermore, the above permanent dipole moment, T1, and S1 were calculated using molecular orbital calculations. As the calculation method of the molecular orbital calculation method, the density functional theory (DFT), which is currently widely used, was used. The functional B3LYP and the basis function 6-31G* were used.The molecular orbital calculation method was also performed using 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.). Hereinafter, the molecular orbital calculations in this specification use the same method.

[0047] Specific examples of the organic compounds of the present invention are shown below. However, the organic compounds of the present invention are not limited thereto.

[0048]

Chemical formula

[0049]

Chemical formula

[0050]

Chemical formula

[0051]

Chemical formula

[0052]

Chemical formula

[0053]

Chemical formula

[0054]

Chemical formula

[0055]

Chemical formula

[0056]

Chemical formula

[0057] Exemplary compounds belonging to Group A have p = 1, m and n = 0 in the general formula [1], and L 1It is a group of compounds having biphenyl or terphenylene. Among the compounds of the present invention, the compounds of Group A have many free-rotation sites and are relatively easy to sublime, so they have the effect of increasing the margin between the sublimation temperature and the decomposition temperature.

[0058] Exemplary compounds belonging to Group B, in general formula [1], p = 1, m and n = 0, and L 1 is a group of compounds having one or more dibenzothiophene, xanthone, or combinations thereof. Among the compounds of the present invention, the compounds of Group B have three or more condensed ring structures composed of three or more rings, so they have high thermal stability. Furthermore, when having a dibenzothiophene ring, it has the effect of good compatibility with metal complexes, and when having two or more highly polar xanthone rings, it also has the effect of good compatibility with metal complexes.

[0059] Exemplary compounds belonging to Group C, in formula [1], m = 1, n = 0, and L 2 is a group of compounds having one or more benzenes, dibenzothiophenes, or combinations thereof. Among the compounds of the present invention, the compounds of Group C have an electron-transporting xanthone located closer to the center of the molecule and have a shape in which unshared electron pairs are protected, and thus have the effect of high stability against oxidation-reduction.

[0060] Exemplary compounds belonging to Group D are a group of compounds with n = 1. Among the compounds of the present invention, the compounds of Group D have two indolocarbazole rings substituted, have high hole-transporting ability, and have the effect of higher hole mobility.

[0061] 〔Organic light-emitting element〕 <Layer structure> Next, the organic light-emitting device of the present invention will be described. The organic light-emitting device of the present invention has at least a first electrode, a second electrode, and an organic compound layer disposed between these electrodes, and is characterized in that the organic compound layer contains the organic compound of the present invention. The organic compound layer is mainly composed of an organic compound, but may contain inorganic atoms or inorganic compounds. For example, it may have copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, etc. The organic compound layer may be disposed between the first electrode and the second electrode, or may be disposed in contact with the first electrode and the second electrode.

[0062] One of the first electrode and the second electrode is an anode and the other is a cathode. In the organic light-emitting device of the present invention, the organic compound layer may be a single layer as long as it has a light-emitting layer, or may be a laminate composed of a plurality of layers. Here, when the organic compound layer is a laminate composed of a plurality of layers, the organic compound layer may have, in addition to the light-emitting layer, a hole injection layer, a hole transport layer, an electron blocking layer, a hole / exciton blocking layer, an electron transport layer, an electron injection layer, etc. Further, the light-emitting layer may be a single layer or a laminate composed of a plurality of layers.

[0063] In the organic light-emitting device of the present invention, at least one layer of the above organic compound layer contains the organic compound of the present invention. Specifically, the organic compound of the present invention is included in any one of the above-described light-emitting layer, hole injection layer, hole transport layer, electron blocking layer, hole / exciton blocking layer, electron transport layer, electron injection layer, etc. The organic compound of the present invention is preferably included in the hole transport layer, electron blocking layer, hole / exciton blocking layer, electron transport layer, and light-emitting layer. More preferably, it is included in the light-emitting layer.

[0064] The light-emitting layer contains an organic compound and a light-emitting compound. The organic compound is also referred to as a host or a host material, and is the compound having the largest mass ratio among the compounds constituting the light-emitting layer. The light-emitting compound is also referred to as a guest, a guest material, or a light-emitting material, and is a compound having a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer and is the compound responsible for the main emission.

[0065] The organic compound of the present invention is preferably used as a host for a light-emitting layer. Further, the light-emitting layer may contain, in addition to the organic compound of the present invention, a second organic compound as a second host. The concentration of each of these hosts is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 80% by mass or less, and even more preferably 30% by mass or more and 70% by mass or less of the entire light-emitting layer. The concentration of the guest with respect to the host is 0.01% by mass or more and 50% by mass or less, preferably 0.1% by mass or more and 20% by mass or less, based on the total amount of the constituent materials of the light-emitting layer. From the viewpoint of suppressing concentration quenching, the concentration of the guest is particularly preferably 10% by mass or less. The guest may be uniformly contained in the entire layer in which the host serves as a matrix, or may be contained with a concentration gradient. Further, the guest may be partially contained in a specific region within the layer, and the light-emitting layer may be a layer having a region of only the host that does not contain the guest.

[0066] The light-emitting layer of the present invention may be a single layer or a multi-layer, and by including a light-emitting material having another emission color, it is also possible to mix colors. The multi-layer means a state in which a first light-emitting layer and a second light-emitting layer different from the first light-emitting layer are laminated. In this case, the emission color of the organic light-emitting element is not particularly limited. More specifically, it may be white or an intermediate color. In the case of white, for example, if the emission color of the first light-emitting layer is blue, the second light-emitting layer emits a color different from blue, that is, green or red. Further, a third light-emitting layer that emits blue light and a charge generation layer may be provided between the single-layer light-emitting layer or the laminated light-emitting layer and the first or second electrode. The charge generation layer exhibits the function as a tandem element, and electrons generated from the charge generation layer and holes injected from the first electrode are charge-recombined to generate excitons, and holes generated from the charge generation layer and electrons injected from the second electrode are charge-recombined to form excitons. Therefore, the internal quantum efficiency is doubled. At that time, the organic light-emitting element of the present invention can be applied to one side of the tandem element as a yellow light-emitting layer as a complementary color of blue light emission. Therefore, by using a laminated light-emitting layer and forming a blue light-emitting layer and a tandem element configuration, a white light-emitting element can be provided. The third light-emitting layer contains at least a third organic compound and a fourth organic compound. The third organic compound is a host material, and the fourth organic compound is a blue light-emitting material.

[0067] Further, the light-emitting layer according to the present invention preferably contains an electron-transporting compound. Phosphorescent compounds typified by iridium complexes often have a shallow HOMO and are excellent in hole-transporting properties. On the contrary, since the LUMO becomes shallow, it is often unstable in the anionic state and poor in electron-transporting properties. Therefore, mixing another electron-transporting compound is preferable because it is possible to increase the electron-transporting ability and form a more stable light-emitting layer. The film-forming method of the light-emitting layer is preferably performed by vapor deposition or coating film formation.

[0068] As a specific element configuration of the organic light-emitting device of this embodiment, a multilayer element configuration in which electrode layers and organic compound layers shown in the following (1) to (6) are sequentially stacked on a substrate can be mentioned. In any element configuration, the organic compound layer always includes a light-emitting layer having a light-emitting material. (1) Anode / Light-emitting layer / Cathode (2) Anode / Hole transport layer / Light-emitting layer / Electron transport layer / Cathode (3) Anode / Hole transport layer / Light-emitting layer / Electron transport layer / Electron injection layer / Cathode (4) Anode / Hole injection layer / Hole transport layer / Light-emitting layer / Electron transport layer / Cathode (5) Anode / Hole injection layer / Hole transport layer / Light-emitting layer / Electron transport layer / Electron injection layer / Cathode (6) Anode / Hole transport layer / Electron blocking layer / Light-emitting layer / Hole blocking layer / Electron transport layer / Cathode

[0069] However, these element configuration examples are only very basic element configurations and are not limited thereto. For example, an insulating layer, an adhesive layer, or an interference layer may be provided at the interface between the electrode and the organic compound layer, the electron transport layer or the hole transport layer may be composed of two layers having different ionization potentials, the light-emitting layer may be composed of two layers having different light-emitting materials, and various layer configurations can be adopted.

[0070] Among the element configurations shown in the above (1) to (6), the configuration of (6) is preferable because it has both an electron blocking layer and a hole blocking layer. That is, in (6) having an electron blocking layer and a hole blocking layer, both carriers of holes and electrons can be surely confined in the light-emitting layer, so that an organic light-emitting device having no carrier leakage and high luminous efficiency can be obtained.

[0071] Here, in the organic light-emitting device of the present invention, all single bonds that can freely rotate in the organic compound constituting the light-emitting layer are carbon-carbon bonds, preferably sp 2It is preferable that the light-emitting layer is composed of carbon-carbon bonds, that is, the light-emitting layer is composed of a host material with high planarity. This increases the hole transport ability and electron transport ability compared to general organic light-emitting devices. Also, this makes the electron blocking layer and hole blocking layer play important roles. For example, since the hole blocking layer needs to be stable against holes, the hole blocking layer compound is preferably an organic compound with low reactivity, and more preferably an organic compound composed only of hydrocarbons. For example, since the electron blocking layer also needs to be stable against electrons, the compound constituting the electron blocking layer is an organic compound with low reactivity, and further, all single bonds capable of free rotation are carbon-carbon bonds, preferably sp 2 It is preferably an organic compound composed of carbon-carbon bonds.

[0072] As the light extraction mode (element form) of the light output from the light-emitting layer, a so-called bottom emission method of extracting light from the electrode on the substrate side may be used, or a so-called top emission method of extracting light from the opposite side of the substrate may be used. Also, a double-sided extraction method of extracting light from both the substrate side and the opposite side of the substrate can be adopted.

[0073] <Constituent Materials of Organic Compound Layers> The organic compound of the present invention can also be used as a constituent material of organic compound layers other than the light-emitting layer constituting the organic light-emitting device of the present invention. Specifically, it may be used as a constituent material of an electron transport layer, an electron injection layer, a hole transport layer, a hole injection layer, a hole blocking layer, etc. In this case, the emission color of the organic light-emitting device is not particularly limited. More specifically, it may be white or an intermediate color.

[0074] In the organic light-emitting device of the present invention, conventionally known low-molecular and high-molecular hole injection compounds or hole transport compounds, host compounds, light-emitting compounds, electron injection compounds or electron transport compounds, etc. can be used together as needed. Examples of these compounds are given below.

[0075] As the positive hole injection and transport material, a material with a high hole mobility is preferred so as to facilitate the injection of positive holes from the anode and transport the injected positive holes to the light-emitting layer. Further, in order to suppress the deterioration of the film quality such as crystallization in the organic light-emitting device, a material with a high glass transition temperature is preferred. Examples of the low molecular weight and high molecular weight materials having positive hole injection and 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 positive hole injection and transport materials are also preferably used for the electron blocking layer. Specific examples of the compounds used as the positive hole injection and transport materials are shown below, but are of course not limited thereto.

[0076]

Chemical formula

[0077] As the light-emitting material mainly related to the light-emitting function, in addition to the organometallic complex, condensed ring compounds (for example, 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(phenylene vinylene) derivatives, poly(fluorene) derivatives, and poly(phenylene) derivatives can be mentioned. Specific examples of the compounds used as the light-emitting material are shown below, but are of course not limited thereto.

[0078]

Chemical formula

[0079]

Chemical formula

[0080] As a host or assist material contained in the light-emitting layer, a compound other than the organic compound of the present invention may be contained as a third component. Examples of the third component include, in addition to aromatic hydrocarbon compounds or their derivatives, carbazole derivatives, azine derivatives, xanthone derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, and organoaluminum complexes such as tris(8-quinolinolato)aluminum, and organoberyllium complexes.

[0081]

Chemical formula

[0082] As the electron transporting material, it 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. Materials having electron transporting performance include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organoaluminum complexes, and condensed ring compounds (for example, fluorene derivatives, naphthalene derivatives, chrysene derivatives, anthracene derivatives, etc.). Furthermore, the above electron transporting materials are also preferably used for the hole blocking layer. Specific examples of the compounds used as the electron transporting material are shown below, but of course, they are not limited thereto.

[0083]

Chemical formula

[0084] As the electron injection material, it can be arbitrarily selected from those that enable easy electron injection from the cathode, and is selected in consideration of the balance with hole injection properties, etc. Organic compounds also include n-type dopants and reducing dopants. For example, compounds containing alkali metals such as lithium fluoride, lithium complexes such as lithium quinolinol, benzimidazolidene derivatives, imidazolidene derivatives, fulvalene derivatives, and acridine derivatives can be mentioned. It can also be used in combination with the above electron transport material.

[0085] 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.) of the organic light emitting device of the present invention are formed by the methods shown below. For example, dry processes such as vacuum evaporation, ionization evaporation, sputtering, and plasma can be used. Instead of the dry process, a wet process of dissolving in an appropriate solvent and forming a layer by a known coating method (for example, spin coating, dipping, casting method, LB method, inkjet method, etc.) can also be used. Here, when forming a layer by a vacuum evaporation method, a solution coating method, etc., crystallization, etc. hardly occurs and the stability over time is excellent. When forming a film by a coating method, a film can also be formed in combination with an appropriate binder resin.

[0086] Examples of the above binder resin include, but are not limited to, polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, urea resin, etc. In addition, these binder resins may be used alone as a homopolymer or copolymer, or two or more kinds may be mixed and used. Furthermore, additives such as known plasticizers, antioxidants, and ultraviolet absorbers may be used in combination as necessary.

[0087] <Constituent materials other than the organic compound layer> An organic light-emitting device is provided by forming an insulating layer, a first electrode, an organic compound layer, and a second electrode on a substrate. A protective layer, a color filter, a microlens, etc. may be provided on the second electrode. When providing a color filter, a planarization layer may be provided between the protective layer. The planarization layer can be composed of an acrylic resin or the like. The same applies when a planarization layer is provided between the color filter and the microlens.

[0088] [Substrate] Examples of the substrate include quartz, glass, silicon wafers, resins, metals, etc. Further, the substrate may be provided with switching elements such as transistors and wiring thereon, and an insulating layer thereon. As the insulating layer, any material may be used as long as a contact hole can be formed so that wiring can be formed between the first electrode and insulation from non-connected wiring can be ensured. For example, resins such as polyimide, silicon oxide, silicon nitride, etc. can be used.

[0089] [Electrode] A pair of electrodes can be used for the electrodes. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the light-emitting direction of the organic light-emitting device, the electrode with the higher potential is the anode, and the other is the cathode. Also, it can 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.

[0090] As the constituent material of the anode, those with as large a work function as possible are good. For example, simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, tungsten, etc., mixtures containing these, alloys combining these, metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide, etc. can be used. Also, conductive polymers such as polyaniline, polypyrrole, polythiophene, etc. can be used. These electrode materials may be used alone or in combination of two or more. Also, the anode may be composed of one layer or multiple layers.

[0091] When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys thereof, laminated materials, etc. can be used. With the above materials, it is also possible to function as a reflective film without having the role of an electrode. When used as a transparent electrode, oxide transparent conductive layers such as indium tin oxide (ITO) and indium zinc oxide can be used, but it is not limited thereto. For the formation of the electrode, photolithography technology can be used.

[0092] On the other hand, as the constituent material of the cathode, those with a small work function are preferable. For example, alkali metals such as lithium, alkaline earth metals such as calcium, single metals such as aluminum, titanium, manganese, silver, lead, chromium, or mixtures containing these can be mentioned. Alternatively, alloys combining these single metals can also be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, zinc-silver, etc. can be used. The use of metal oxides such as indium tin oxide (ITO) is also possible. These electrode materials may be used alone or in combination of two or more. Also, the cathode may have a single-layer structure or a multi-layer structure. Among them, it is preferable to use silver, and in order to reduce the aggregation of silver, it is more preferable to use a silver alloy. As long as the aggregation of silver can be reduced, the ratio of the alloy does not matter. For example, silver: other metals may be 1:1, 3:1, etc.

[0093] 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. As the formation method of the cathode, although not particularly limited, the use of direct current and alternating current sputtering methods, etc. is more preferable because the film coverage is good and the resistance is easily reduced.

[0094] [Protective layer] A protective layer may be provided on the second electrode. For example, by adhering a glass provided with a moisture absorbent on the second electrode, the intrusion of water or the like into the organic compound layer can be reduced, and the occurrence of display defects can be reduced. Further, as another embodiment, a passivation film such as silicon nitride may be provided on the second electrode to reduce the intrusion of water or the like into the organic compound layer. For example, after forming the second electrode, it may be transported to another chamber without breaking the vacuum, and a silicon nitride film with a thickness of 2 μm may be formed by CVD method, which may also serve as a protective layer. A protective layer using atomic layer deposition (ALD method) may be provided after the film formation by CVD method. The material of the film by ALD method is not limited, but it may be silicon nitride, silicon oxide, aluminum oxide, etc. Silicon nitride may be further formed by CVD method on the film formed by ALD method. The film by ALD method may have a smaller film thickness than the film formed by CVD method. Specifically, it may be 50% or less, and further 10% or less.

[0095] [Color filter] A color filter may be provided on the protective layer. For example, a color filter considering the size of the organic light-emitting element may be provided on another substrate, and it may be bonded to the substrate provided with the organic light-emitting element, or the color filter may be patterned on the above-described protective layer using photolithography technology. The color filter may be composed of a polymer.

[0096] [Planarization layer] A planarization layer may be provided between the color filter and the protective layer. The planarization layer is provided for the purpose of reducing the unevenness of the underlying layer. Without limiting the purpose, it may sometimes be called a material resin layer. The planarization layer may be composed of an organic compound, a low molecule, or a polymer, but it is preferably a polymer. The planarization layer may be provided above and below the color filter, and its constituent materials may be the same or different. Specifically, examples include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, urea resin, etc.

[0097] [Micro lens] An organic light-emitting element or an organic light-emitting device having the organic light-emitting element may have an optical member such as a micro lens on its light-emitting side. The micro lens can be made of an acrylic resin, an epoxy resin, or the like. The micro lens may be for the purpose of increasing the amount of light extracted from the organic light-emitting element or the organic light-emitting device and controlling the direction of the extracted light. The micro lens may have a hemispherical shape. When having a hemispherical shape, among the tangents in contact with the hemisphere, there is a tangent parallel to the insulating layer, and the contact point between the tangent and the hemisphere is the vertex of the micro lens. The vertex of the micro lens can be determined in the same manner in any cross-sectional view. That is, among the tangents in contact with the semi-circle of the micro lens in the cross-sectional view, there is a tangent parallel to the insulating layer, and the contact point between the tangent and the semi-circle is the vertex of the micro lens. Also, the midpoint of the micro lens can be defined. In the cross-section of the micro lens, a line segment from the point where the arc shape ends to the point where another arc shape ends can be imagined, and the midpoint of the line segment can be called the midpoint of the micro lens. The cross-section for discriminating the vertex and the midpoint may be a cross-section perpendicular to the insulating layer.

[0098] [Counter substrate] A counter substrate may be provided on the planarization layer. Since the counter substrate is provided at a position corresponding to the aforementioned substrate, it is called a counter substrate. The constituent material of the counter substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate is taken as the first substrate, the counter substrate may be the second substrate.

[0099] [Pixel circuit] An organic light-emitting device having an organic light-emitting element may have a pixel circuit connected to the organic light-emitting element. The pixel circuit may be an active matrix type that independently controls the light emission of a plurality of light-emitting elements. The active matrix type circuit may be voltage programming or current programming. The driving circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor that controls the light emission luminance of the light-emitting element, a transistor that controls the light emission timing, a capacitor that holds the gate voltage of the transistor that controls the light emission luminance, and a transistor for connecting to GND without passing through the light-emitting element.

[0100] The light-emitting device has a display area and a peripheral area arranged around the display area. The display area has a pixel circuit, and the peripheral area has a display control circuit. The mobility of the transistors constituting the pixel circuit may be smaller than the mobility of the transistors constituting the display control circuit. The slope of the current-voltage characteristics of the transistors constituting the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistors constituting the display control circuit. The slope of the current-voltage characteristics can be measured by so-called Vg-Ig characteristics. The transistors constituting the pixel circuit are the transistors connected to the light-emitting element.

[0101] [Pixel] An organic light-emitting device having an organic light-emitting element may have a plurality of pixels. The pixels have sub-pixels that emit different colors from each other. The sub-pixels may have, for example, light emission colors of RGB respectively. Light is emitted from a region also called a pixel aperture. This region is the same as the first region. The pixel aperture may be 15.0 μm or less, and may be 5.0 μm or more. More specifically, it may be 11.0 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc. The distance between sub-pixels may be 10.0 μm or less, and specifically may be 8 μm, 7.4 μm, 6.4 μm. In a plan view, the pixels can take a known arrangement form. For example, it may be a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the sub-pixels in the plan view can be any known shape. For example, it can be a quadrilateral such as a rectangle or a rhombus, a hexagon, etc. Of course, even if it is not an exact figure but a shape close to a rectangle, it is included in the rectangle. The shape of the sub-pixels and the pixel arrangement can be used in combination.

[0102] <Applications of the organic light-emitting element> The organic light-emitting element according to the present invention can be used as a component of a display device or a lighting device. In addition, there are applications such as an exposure light source of an electrophotographic image forming device, a backlight of a liquid crystal display device, and a light-emitting device having a color filter for a white light source. The display device may be an image information processing device that has an image input unit for inputting image information from an area CCD, a linear CCD, a memory card, etc., has an information processing unit for processing 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 according to the present invention and a transistor connected to the organic light-emitting element. In addition, the display unit of an imaging device or an inkjet printer may have a touch panel function. The driving method of this touch panel function may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method, and is not particularly limited. Also, the display device may be used for the display unit of a multifunction printer.

[0103] Next, a display device according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional schematic view showing an example of a display device having an organic light-emitting element and a transistor connected to this organic light-emitting element. The transistor is an example of an active element. The transistor may be a thin film transistor (TFT).

[0104] FIG. 1(a) is an example of a pixel which is a component of the display device according to the present invention. The pixel has sub-pixels 10. The sub-pixels are divided into 10R, 10G, and 10B by their light emission. The emission color may be distinguished by the wavelength emitted from the light-emitting layer, or the light emitted from the sub-pixels may be selectively transmitted or color-converted by a color filter or the like. Each sub-pixel 10 has a reflective electrode which is a first electrode 2 on an interlayer insulating layer 1, an insulating layer 3 covering an end of the first electrode 2, an organic compound layer 4 covering the first electrode 2 and the insulating layer 3, a transparent electrode which is a second electrode 5, a protective layer 6, and a color filter 7.

[0105] A transistor and a capacitor element may be arranged in or under the interlayer insulating layer 1. The transistor and the first electrode 2 may be electrically connected via a contact hole or the like (not shown).

[0106] The insulating layer 3 is also called a bank or a pixel isolation film. It covers an end of the first electrode 2 and is arranged surrounding the first electrode 2. The portion where the insulating layer 3 is not arranged is in contact with the organic compound layer 4 and becomes a light-emitting region.

[0107] The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transmissive electrode.

[0108] The protective layer 6 reduces the penetration of moisture into the organic compound layer 4. The protective layer 6 is shown as a single layer, but may be a plurality of layers. Each layer may have an inorganic compound layer and an organic compound layer.

[0109] The color filter 7 is divided into 7R, 7G, and 7B according to its color. The color filter 7 may be formed on a planarization film (not shown). Also, it may have a resin protective layer (not shown) on the color filter 7. Further, the color filter 7 may be formed on the protective layer 6. Or it may be bonded after being provided on a counter substrate such as a glass substrate.

[0110] The display device in Fig. 1(b) has an organic light-emitting element 26 and a TFT 18 as an example of a transistor. A substrate 11 such as glass or silicon and an insulating layer 12 are provided on the upper part thereof. Active elements such as the TFT 18 are arranged on the insulating layer 12, and a gate electrode 13, a gate insulating film 14, and a semiconductor layer 15 of the active element are arranged. The TFT 18 is also composed of a drain electrode 16 and a source electrode 17. An insulating film 19 is provided on the upper part of the TFT 18. The anode 21 constituting the organic light-emitting element 26 and the source electrode 17 are connected via a contact hole 20 provided in the insulating film 19.

[0111] Note that the electrical connection method between the electrodes (anode 21, cathode 23) included in the organic light-emitting element 26 and the electrodes (source electrode 17, drain electrode 16) included in the TFT 18 is not limited to the mode shown in Fig. 1(b). That is, any one of the anode 21 or the cathode 23 and any one of the source electrode 17 or the drain electrode 16 of the TFT 18 may be electrically connected. TFT refers to a thin-film transistor.

[0112] In the display device of Fig. 1(b), the organic compound layer 22 is illustrated as one layer, but the organic compound layer 22 may be a plurality of layers. A first protective layer 24 and a second protective layer 25 for reducing the deterioration of the organic light-emitting element 26 are provided on the cathode 23.

[0113] In the display device of Fig. 1(b), a transistor is used as a switching element, but other switching elements may be used instead.

[0114] Also, the transistor used in the display device of Fig. 1(b) is not limited to a transistor using a single-crystalline silicon wafer, and may be a thin-film transistor having an active layer on an insulating surface of a substrate. Examples of the active layer include non-single-crystalline silicon such as single-crystalline silicon, amorphous silicon, and microcrystalline silicon, and non-single-crystalline oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Note that the thin-film transistor is also called a TFT element.

[0115] The transistor included in the display device of FIG. 1(b) may be formed within a substrate such as an Si substrate. Here, forming within the substrate means fabricating the transistor by processing the substrate itself such as an Si substrate. That is, having a transistor within the substrate can also be regarded as the substrate and the transistor being integrally formed.

[0116] The organic light-emitting element according to the present embodiment has its emission luminance controlled by a TFT which is an example of a switching element, and an image can be displayed by the respective emission luminances by providing the organic light-emitting elements in a plurality of planes. Note that the switching element according to the present 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 an Si substrate. "On the substrate" can also mean within the substrate. Whether to provide a transistor within the substrate or use a TFT is selected according to the size of the display portion. For example, if the size is about 0.5 inches, it is preferable to provide the organic light-emitting element on the Si substrate.

[0117] FIG. 2 is a schematic diagram showing an example of the 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 FPC 1002 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, or may be provided at another position even if it is a portable device.

[0118] The display device according to the present embodiment may have a color filter having red, green, and blue. The color filter may have the red, green, and blue arranged in a delta array.

[0119] The display device according to the present embodiment may be used for the display unit of a mobile terminal. In that case, it may have both a display function and an operation function. Examples of the mobile terminal include mobile phones such as smartphones, tablets, head-mounted displays, and the like.

[0120] The display device according to the present embodiment may be used for the display unit of an imaging device having an optical unit with a plurality of lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. Further, the display unit may be a display unit exposed to the outside of the imaging device or a display unit disposed within the viewfinder. The imaging device may be a digital camera or a digital video camera.

[0121] FIG. 3(a) is a schematic diagram showing an example of the imaging device according to the present 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 has the display device according to the present embodiment. In that case, the display device may display not only the image to be captured but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the speed at which the subject moves, the possibility that the subject is shielded by an obstacle, and the like.

[0122] Since the timing suitable for imaging is a very short time, it is better to display information as soon as possible. Therefore, it is preferable to use the display device using the organic light-emitting element of the present invention. This is because the organic light-emitting element has a high response speed. The display device using the organic light-emitting element can be more preferably used than these devices and liquid crystal display devices that require a high display speed.

[0123] The imaging device 1100 has an optical unit (not shown). The optical unit has a plurality of lenses and forms an image on an imaging element housed in the housing 1104. The plurality of lenses can adjust the focus by adjusting their relative positions. This operation can also be performed automatically. The imaging device may be called a photoelectric conversion device. The photoelectric conversion device can include, as imaging methods, a method of detecting the difference from a previous image instead of sequential imaging, a method of cutting out from an image that is always recorded, and the like.

[0124] FIG. 3(b) is a schematic diagram showing an example of the electronic device according to the present 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 reaction unit of a touch panel method. The operation unit 1202 may be a biometric recognition unit that recognizes a fingerprint and performs unlocking or the like. An electronic device having a communication unit can also be called a communication device. The electronic device 1200 may further have a camera function by including a lens and an imaging element. An image captured by the camera function is displayed on the display unit 1201. Examples of the electronic device 1200 include a smartphone and a notebook personal computer.

[0125] FIG. 4 is a schematic diagram showing an example of the display device according to the present embodiment. FIG. 4(a) shows a display device such as a TV monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The organic light-emitting element of the present invention is used for the display unit 1302. Further, it has a base 1303 that supports the frame 1301 and the display unit 1302. The base 1303 is not limited to the form of FIG. 4(a). The lower side of the frame 1301 may also serve as the base. Further, 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.

[0126] 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 foldable and 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 have the organic light-emitting element of the present invention. The first display unit 1311 and the second display unit 1312 may be a single seamless display device. 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 may display one image together with the first and second display units.

[0127] FIG. 5(a) is a schematic diagram showing an example of the lighting device according to the present embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical filter 1404 that transmits the light emitted by the light source 1402, and a light diffusing unit 1405. The light source 1402 has the organic light-emitting element of the present invention. The optical filter 1404 may be a filter that improves the color rendering property of the light source. The light diffusing unit 1405 can effectively diffuse the light of the light source, such as lighting up, and deliver the light to a wide range. The optical filter 1404 and the light diffusing unit 1405 may be provided on the light-emitting side of the lighting. If necessary, a cover may be provided on the outermost part.

[0128] The lighting device is, for example, a device for lighting a room. The lighting device may emit any color from white, day white, or other blue to red. It may also have a dimming circuit for dimming them. The lighting device has the organic light-emitting element of the present invention and a power supply circuit connected thereto. The power supply circuit is a circuit that converts an AC voltage into a DC voltage. Also, white has a color temperature of 4200K and day white has a color temperature of 5000K. The lighting device may have a color filter.

[0129] Also, the lighting device according to the present embodiment may have a heat radiating part. The heat radiating part releases the heat inside the device to the outside of the device, and examples include metals with high specific heat and liquid silicon.

[0130] FIG. 5(b) is a schematic diagram of an automobile which is an example of a moving body according to the present embodiment. The automobile has a tail lamp which is an example of a lighting device. The automobile 1500 may have a tail lamp 1501 and may be configured to turn on the tail lamp when a braking operation or the like is performed.

[0131] The tail lamp 1501 has the organic light emitting element of the present invention. The tail lamp 1501 may have a protective member for protecting the organic light emitting element. The protective member has a certain degree of strength and may be made of any material as long as it is transparent, but is preferably made of polycarbonate or the like. A phthalic acid derivative, an acrylonitrile derivative or the like may be mixed with the polycarbonate.

[0132] The automobile 1500 may have a vehicle body 1503 and a window 1502 attached thereto. The window 1502 may be a transparent display as long as it is not a window for checking the front and rear of the automobile. The transparent display has the organic light emitting element of the present invention. In this case, the constituent materials such as the electrodes of the organic light emitting element are made of transparent members.

[0133] The moving body according to the present embodiment may be a ship, an aircraft, a drone or the like. The moving body has a fuselage and a lighting device provided on the fuselage, and the lighting device may emit light for notifying the position of the fuselage. The lighting device has the organic light emitting element of the present invention.

[0134] With reference to FIG. 6, application examples of the display device of each of the above embodiments will be described. The display device can be applied to a system wearable as a wearable device such as, for example, smart glasses, an HMD, or smart contacts. The imaging display device used in such an application example has an imaging device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

[0135] FIG. 6(a) is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention. Using FIG. 6(a), glasses 1600 (smart glasses) according to one application example will be described. An imaging device 1602 such as a CMOS sensor or a SPAD is provided on the front surface side of the lens 1601 of the glasses 1600. Further, a display device of each of the above-described embodiments is provided on the back surface side of the lens 1601.

[0136] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the imaging device 1602 and the display device. Further, the control device 1603 controls the operations of the imaging device 1602 and the display device. An optical system for condensing light onto the imaging device 1602 is formed in the lens 1601.

[0137] FIG. 6(b) is a schematic diagram showing another example of a wearable device according to an embodiment of the present invention. Using FIG. 6(b), glasses 1610 (smart glasses) according to one application example will be described. The glasses 1610 have a control device 1612, and an imaging device corresponding to the imaging device 1602 in FIG. 6(a) and a display device are mounted on the control device 1612. An optical system for projecting light emitted from the imaging device and the display device is formed in the lens 1611, and an image is projected onto the lens 1611. The control device 1612 functions as a power source that supplies power to the imaging device and the display device, and controls the operations of the imaging device and the display device.

[0138] The control device 1612 may have a gaze detection unit that detects the wearer's gaze. The detection of the gaze may use infrared light. The infrared light emitting unit emits infrared light toward the eyes of the user who is gazing at the display image. An imaging unit having a light receiving element detects the reflected light of the emitted infrared light from the eyes, thereby obtaining an imaging image of the eyes. By having a reducing means for reducing the light from the infrared light emitting unit to the display unit in a plan view, a decrease in image quality is reduced. The gaze of the user with respect to the display image is detected from the imaging image of the eyes obtained by imaging the infrared light. Any known method can be applied to the gaze detection using the imaging image of the eyes. As an example, a gaze detection method based on the Purkinje image by the reflection of the irradiation light on the cornea can be used. More specifically, gaze detection processing based on the pupil corneal reflection method is performed. Using the pupil corneal reflection method, a gaze vector representing the orientation (rotation angle) of the eyes is calculated based on the image of the pupil and the Purkinje image included in the imaging image of the eyes, thereby detecting the gaze of the user.

[0139] The display device according to an embodiment of the present invention may include an imaging device having a light receiving element, and may control the display image of the display device based on the user's gaze information from the imaging device. Specifically, the display device determines a first visual field region that the user gazes at and a second visual field region other than the first visual field region based on the gaze information. The first visual field region and the second visual field region may be determined by the control device of the display device, or may receive those determined by an external control device. In the display area of the display device, the display resolution of the first visual field region may be controlled to be higher than the display resolution of the second visual field region. That is, the resolution of the second visual field region may be made lower than that of the first visual field region.

[0140] In addition, the display area has a first display area and a second display area different from the first display area, and based on the line-of-sight information, an area with a higher priority is determined from the first display area and the second display area. The first field of view area and the second field of view area may be determined by the control device of the display device, or may receive those determined by an external control device. The resolution of the area with a higher priority may be controlled to be higher than the resolution of the areas other than the area with a higher priority. That is, the resolution of the area with a relatively lower priority may be lowered.

[0141] In addition, AI may be used to determine the first field of view area or the area with a higher priority. AI may be a model configured to estimate the angle of the line of sight and the distance to the object at the tip of the line of sight from the image of the eyeball, using the image of the eyeball and the direction in which the eyeball of the image is actually looking as teacher data. The AI program may be possessed by the display device, the imaging device, or an external device. When it is possessed by an external device, it is transmitted to the display device via communication.

[0142] When performing display control based on visual recognition detection, it is preferably applicable to smart glasses further having an imaging device for imaging the outside. The smart glasses can display the imaged external information in real time.

[0143] FIG. 7(a) is a schematic diagram showing an example of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus 40 is an electrophotographic image forming apparatus and has a photoreceptor 27, an exposure light source 28, a charging unit 30, a developing unit 31, a transferrer 32, a conveyance roller 33, and a fixing unit 35. Light 29 is irradiated from the exposure light source 28, and an electrostatic latent image is formed on the surface of the photoreceptor 27. This exposure light source 28 has the organic light emitting element of the present invention. The developing unit 31 has toner and the like. The charging unit 30 charges the photoreceptor 27. The transferrer 32 transfers the developed image to the recording medium 34. The conveyance roller 33 conveys 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.

[0144] Figures 7(b) and 7(c) are diagrams showing the exposure light source 28, and are schematic diagrams showing a state in which a plurality of light emitting portions 36 are arranged on a long substrate. Arrow 37 is a direction parallel to the axis of the photoreceptor, and represents the column direction in which the organic light emitting elements are arranged. This column direction is the same as the direction of the axis around which the photoreceptor 27 rotates. This direction can also be referred to as the major axis direction of the photoreceptor 27. Figure 7(b) shows a form in which the light emitting portion 36 is arranged along the major axis direction of the photoreceptor 27. Figure 7(c) shows a form different from that of Figure 7(b), in which the light emitting portions 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 portions 36 are arranged at intervals. The second column has light emitting portions 36 at positions corresponding to the intervals between the light emitting portions 36 in the first column. That is, also in the row direction, a plurality of light emitting portions 36 are arranged at intervals. The arrangement in Figure 7(c) can also be described as, for example, a state of being arranged in a grid pattern, a state of being arranged in a staggered grid, or a checkered pattern.

[0145] As described above, by using the device using the organic light emitting element according to the present embodiment, it is possible to obtain a good image quality and a stable display even for a long-time display.

[0146] 〔Constituents included〕 The disclosure of the present embodiment includes the following configurations. (Configuration 1) An organic compound characterized by being represented by the following general formula [1].

[0147]

Chemical formula

[0148] 〔In the above general formula [1], p, m, and n are each independently 0 or 1, and p + m + n ≧ 1, L 1is a divalent substituent derived from any of a substituted or unsubstituted biphenyl, terphenyl, dibenzothiophene, or a combination of q benzenes, r dibenzothiophenes, and s xanthones, where q, r, and s are each independently an integer of 0 or 1 or more, and q + r + s ≥ 2. L 2 is a monovalent or divalent substituent derived from any of a substituted or unsubstituted benzene, biphenyl, terphenyl, dibenzothiophene, or a combination of q benzenes, r dibenzothiophenes, and s xanthones, where q, r, and s are each independently an integer of 0 or 1 or more, and q + r + s ≥ 2. HAr 1 and HAr 2 are each independently represented by any of the following general formulas [2-1] to [2-3].

[0149] [Chemical formula]

[0150] In the above general formulas [2-1] to [2-3], R 10 to R 40 are selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, and a substituted or unsubstituted silyl group.

[0151] (Constitution 2) The above L 1 is a monovalent or divalent substituent derived from a combination of one or more substituted or unsubstituted dibenzothiophenes and two or more substituted or unsubstituted xanthones, and the organic compound according to Constitution 1, characterized in that. (Constitution 3) The above L 1 is represented by any of the following general formulas [3-1] to [3-5], and the organic compound according to Constitution 1 or 2, characterized in that.

[0152] [Chemical formula]

[0153] 〔In the above general formulas [3-1] to [3-5], * indicates the bonding position.〕 (Constitution 4) The organic compound according to any one of Constitutions 1 to 3, characterized in that n is 0.

[0154] (Constitution 5) In an organic light-emitting device having a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode, the organic compound layer contains the organic compound according to any one of Constitutions 1 to 4, and the organic light-emitting device is characterized thereby. (Constitution 6) the organic compound layer has a light-emitting layer, the light-emitting layer contains the organic compound, and the organic light-emitting device according to Constitution 5 is characterized thereby. (Constitution 7) the light-emitting layer contains a phosphorescent compound, and the organic light-emitting device according to Constitution 6 is characterized thereby. (Constitution 8) the light-emitting layer contains an electron-transporting compound, and the organic light-emitting device according to Constitution 7 is characterized thereby. (Constitution 9) the organic compound layer has a second light-emitting layer disposed by laminating with the first light-emitting layer, with the first light-emitting layer being the first light-emitting layer, the second light-emitting layer emits light of a color different from the light-emitting color emitted by the first light-emitting layer, and the organic light-emitting device according to any one of Constitutions 6 to 8 is characterized thereby. (Constitution 10) The organic light-emitting device according to Constitution 9, characterized in that it emits white light.

[0155] (Constitution 11) A display device having a plurality of pixels, characterized in that at least one of the plurality of pixels has the organic light-emitting device according to any one of Constitutions 5 to 10 and a transistor connected to the organic light-emitting device. (Constitution 12) An optical unit having a plurality of lenses, an imaging element that receives light that has passed through the optical unit, and a display unit that displays an image captured by the imaging element. The display unit has an organic light-emitting element according to any one of Configurations 5 to 10, and the photoelectric conversion device is characterized by this. (Configuration 13) An electronic device, comprising: a display unit having an organic light-emitting element according to any one of Configurations 5 to 10; a housing provided with the display unit; and a communication unit provided in the housing and communicating with the outside. (Configuration 14) An illumination device, comprising: a light source having an organic light-emitting element according to any one of Configurations 5 to 10; and a light diffusing unit or an optical filter that transmits light emitted by the light source. (Configuration 15) A moving body, comprising: a lighting fixture having an organic light-emitting element according to any one of Configurations 5 to 10; and a body provided with the lighting fixture. (Configuration 16) An image forming apparatus, comprising: a photoreceptor; and an exposure light source that exposes the photoreceptor. The exposure light source has an organic light-emitting element according to any one of Configurations 5 to 10, and the image forming apparatus is characterized by this.

Examples

[0156] Hereinafter, the present invention will be described by way of examples. However, the present invention is not limited to these. (Example 1) Exemplary compound A1 was synthesized according to the following reaction formula.

[0157]

Chemical formula

[0158] The following reagents and solvents were charged into a 100 ml eggplant flask. Intermediate 1: 1.00 g (3.63 mmol) Intermediate 2: 1.72 g (3.63 mmol) Palladium(II) acetate (Pd(OAc) 2): 25 mg (0.11 mmol) 2-Dicyclohexylphosphino-2’,6’-dimethoxybiphenyl (s-phos): 163 mg (0.36 mmol) K 3 PO 4 : 1.54 g (7.26 mmol) Toluene: 30 ml Water: 1 ml

[0159] Next, the reaction solution was heated to 90 °C under a nitrogen stream, and stirring was carried out at this temperature (90 °C) for 5 hours. After completion of the reaction, methanol was added and filtration was performed to obtain a crude product as the filtrate. This was purified by silica gel column chromatography (chlorobenzene) and recrystallized from xylene to obtain 1.49 mg (yield: 70%) of Exemplary Compound A1. This Exemplary Compound A1 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF manufactured by Bruker). As a result, the measured value: m / z = 587, calculated value: C 43 H 25 NO 2 = 587.

[0160] (Examples 2 to 30) Exemplary compounds were synthesized in the same manner as in Example 1, except that Intermediate 1 of Example 1 was used as Raw Material 1 and Intermediate 2 was used as Raw Material 2. Raw Materials 1 and 2 for each example are shown in Table 4.

[0161] Also shown are the measured values of m / z of the mass spectrometry results measured in the same manner as in Example 1.

[0162]

Table 4

[0163]

Table 5

[0164]

Table 6

[0165] (Example 31) An organic light-emitting device having a bottom emission type structure 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 sequentially formed on a substrate was fabricated. First, ITO was deposited 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 thus formed was used as an ITO substrate in the following steps. Next, vacuum evaporation by resistance heating was performed in a vacuum chamber of 1.33×10 -4 Pa, and the organic compound layers and electrode layers shown in Table 11 were continuously deposited on the ITO substrate. At this time, the electrode area of the opposing electrode (metal electrode layer, cathode) was made to be 3 mm 2 .

[0166]

Table 7

[0167] Regarding the obtained device, the characteristics of the device were measured and evaluated. The maximum external quantum efficiency (E.Q.E.) of the light-emitting device was 13%. When the time when the luminance degradation rate of Comparative Example 1 described later reached 5% was set to 1.0, the luminance degradation rate ratio of this example was 1.3. Furthermore, a continuous drive test was performed at a current density of 100 mA / cm 2 , and the time when the luminance degradation rate reached 5% was measured. In this example, specifically, the current-voltage characteristics were measured with a microammeter 4140B manufactured by Hewlett-Packard Company, and the emission luminance was measured with a BM7 manufactured by Topcon Corporation.

[0168] (Examples 32 to 54, Comparative Examples 1 and 2) An organic light-emitting device was fabricated in the same manner as in Example 31, except that the compound shown in Table 6 was appropriately changed. The characteristics of the obtained device were measured and evaluated in the same manner as in Example 31. The measurement results are shown in Table 6. The luminance degradation rate ratio was shown as a relative ratio of the time when the luminance degradation rate of the device in Comparative Example 1 reached 5% (set as 1.0) to the time when the luminance degradation rate of the devices in each Example and Comparative Example reached 5%, in the same manner as in Example 1. Incidentally, Comparative Compounds 1-a and 1-b used as hosts in Comparative Examples 1 and 2 are Indolocarbazole Derivatives 1-a and 1-b described in Patent Documents 1 and 2 mentioned above, respectively.

[0169]

Table 8

[0170] As described above, by using the organic compound of the present invention in which an indolocarbazole ring and a xanthone ring are bonded via a benzene ring, a dibenzothiophene ring, or a xanthone ring as a host of the light-emitting layer, the compatibility between the host molecule and the guest molecule is improved, the intermolecular distance is decreased, and the energy transfer efficiency is increased. Therefore, it was found that the redox stability is improved and a device with high efficiency and excellent durability characteristics can be provided.

Explanation of Reference Numerals

[0171] 2,21: First electrode, 8,26: Organic light-emitting device, 5,23: Second electrode, 18: Transistor, 27: Photoconductor, 28: Exposure light source, 1200: Electronic device, 1201,1302,1311,1312: Display unit, 1203: Housing, 1300,1310: Display device, 1400: Lighting device, 1402: Light source, 1404: Optical filter, 1405: Light diffusing part

Claims

1. An organic compound characterized by being represented by the following general formula [1]. 【Chemical 1】 〔In the above general formula [1], p, m, and n are each independently 0 or 1, and p + m + n ≧ 1. L 1 is a divalent substituent derived from any of a substituted or unsubstituted biphenyl, terphenyl, dibenzothiophene, or a combination of q benzenes, r dibenzothiophenes, and s xanthones, where q, r, and s are each independently an integer of 0 or more, and q + r + s ≥ 2. L 2 is a monovalent or divalent substituent derived from any of: substituted or unsubstituted benzene, biphenyl, terphenyl, dibenzothiophene, or a combination of q benzenes, r dibenzothiophenes, and s xanthones, where q, r, and s are each independently an integer of 0 or more, and q + r + s ≥ 2. Har 1 and Har 2 are each independently represented by any of the following general formulas [2-1] to [2-3]. 【Chemical 2】 In the above general formulas [2-1] to [2-3], R 10 to R 40 is selected from a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, and a substituted or unsubstituted silyl group.

2. The above-mentioned L 1 is a monovalent or divalent substituent derived from a combination of one or more substituted or unsubstituted dibenzothiophenes and two or more substituted or unsubstituted xanthones, and the organic compound according to claim 1, characterized in that.

3. The above L 1 The organic compound according to claim 1, wherein L is represented by any one of the following general formulas [3-1] to [3-5]. [Chemical Formula 3] 〔In the above general formulas [3-1] to [3-5], * indicates the bonding position.〕

4. The organic compound according to claim 1, wherein n is 0.

5. In an organic light-emitting device having a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode, The organic light-emitting device, wherein the organic compound layer contains the organic compound according to any one of claims 1 to 4.

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

7. The organic light-emitting device according to claim 6, wherein the light-emitting layer contains a phosphorescent compound.

8. The organic light-emitting device according to claim 7, wherein the light-emitting layer contains an electron-transporting compound.

9. The organic compound layer has a second light-emitting layer laminated and disposed with the first light-emitting layer as the first light-emitting layer, The organic light-emitting device according to claim 6, wherein the second light-emitting layer emits light of a color different from the light-emitting color emitted by the first light-emitting layer.

10. The organic light-emitting device according to claim 9, which emits white light.

11. A display device having a plurality of pixels, wherein at least one of the plurality of pixels has the organic light-emitting device according to claim 5 and a transistor connected to the organic light-emitting device.

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

13. An electronic device having a display unit having the organic light-emitting device according to claim 5, a housing provided with the display unit, and a communication unit provided in the housing for communicating with the outside.

14. An illumination device having a light source having the organic light-emitting device according to claim 5 and a light diffusing unit or an optical filter that transmits light emitted by the light source.

15. A moving body, comprising: a lighting fixture having the organic light-emitting device according to claim 5; and a body provided with the lighting fixture.

16. An image forming apparatus, comprising: a photoreceptor; and an exposure light source that exposes the photoreceptor, wherein the exposure light source has the organic light-emitting device according to claim 5.

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