Organic compound and organic light-emitting device

Abstract

To provide an organic compound that exhibits excellent luminous efficiency when used in an organic light-emitting device, particularly in a luminous layer in the organic light-emitting device.SOLUTION: The present disclosure provides an organic compound represented by general formula [1]. (R3 independently represents a deuterium atom, an alkyl group or the like, l represents an integer of 0 or more and 8 or less, m represents an integer of 1 or more and 3 or less, n represents an integer of 0 or more and 2 or less, where, m+n is 3 and X represents a bidentate ligand).SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] An organic light-emitting device (hereinafter sometimes referred to as an "organic electroluminescence device" or "organic EL device") is an electronic device having a pair of electrodes and an organic compound layer disposed between the electrodes. By injecting electrons and holes from the pair of electrodes, excitons of a light-emitting organic compound in the organic compound layer are generated, and when the excitons return to the ground state, the organic light-emitting device emits light. Recent advances in organic light-emitting devices have been remarkable, including low driving voltage, diverse emission wavelengths, high-speed response, and the possibility of thinning and reducing the weight of light-emitting devices. In order to improve the efficiency of light-emitting elements, elements using highly efficient materials such as phosphorescent materials can be mentioned. Patent Document 1 describes the following compound A-1. Patent Document 2 describes the following compound A-2. Patent Document 3 describes the use of the following compound A-3 as a ligand for an iridium complex.

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

[0004] [Patent Document 1] Chinese Patent Application Publication No. 111690016 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-332291 [Patent Document 3] Japanese Patent Application Publication No. 2019-163239 Summary of the Invention [Problem to be solved by the invention]

[0005] When compound A-1 described in Patent Document 1 or compound A-2 described in Patent Document 2 is used in the light-emitting layer of an organic light-emitting element, there is a problem with luminous efficiency. In addition, the iridium complex using ligand A-3 described in Patent Document 3 has problems with sublimation and vapor deposition stability, and therefore there is a problem with luminous efficiency when used in the light-emitting layer of an organic light-emitting element. The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an organic compound that has excellent luminous efficiency when used in an organic light-emitting device, particularly in an emitting layer in an organic light-emitting device. [Means for solving the problem]

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

[0007] [ka] In formula [1], R1 and R2 are respectively Methyl and ethyl groups are independently selected from R3 is a deuterium atom , placed Substitutional or non-substitutional 1 to 4 carbon atoms Alkyl Base are independently selected, and l represents an integer of 0 to 8. m is an integer between 1 and 3, and n is an integer between 0 and 2, provided that m+n is 3. X represents a bidentate ligand, and the partial structure IrX is either of the structures shown in the following general formula [2] or [3].

[0008] [ka] In formula [2] or [3], R9 to R 19 are hydrogen atoms, deuterium atoms, and Fluorine atom , placed Substitutional or non-substitutional 1 to 4 carbon atoms Alkyl group , placed Substitutional or non-substitutional Phenyl group are selected independently from the adjacent R 16 ~R19 may be bonded to each other to form a ring. Ring A is any of the structures shown in the following general formulas [4] to [7].

[0009] [ka] In formulas [4] to [7], R 20 ~R 29 are hydrogen atoms, deuterium atoms, and Fluorine atom , placed Substitutional or non-substitutional 1 to 4 carbon atoms Alkyl group , placed Substitutional or non-substitutional Phenyl group are independently elected. [Effects of the Invention]

[0010] The organic compound of the present invention can provide an organic compound that is excellent in luminous efficiency when used in an organic light-emitting device, particularly in a light-emitting layer in an organic light-emitting device. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating the characteristics of a compound represented by general formula

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

Embodiments for Carrying Out the Invention

[0012] ≪Organic Compound≫ The organic compound of the present invention is represented by the following general formula [1].

[0013]

Chemical Formula

[0014] <R1 to R2>[[ID= 29]] In formula [1], R1 to R2 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. R1 to R2 are preferably a substituted or unsubstituted alkyl group.

[0015] Examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a tertiary butyl group, a secondary butyl group, an octyl group, a cyclohexyl group, a tertiary pentyl group, a 3-methylpentan-3-yl group, a 1-adamantyl group, a 2-adamantyl group, etc. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms.

[0016] Examples of the silyl group include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0017] Examples of aryl groups include, but are not limited to, phenyl, naphthyl, indenyl, biphenyl, terphenyl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, anthranyl, perylenyl, chrysenyl, and fluoranthenyl groups. Preferred aryl groups have 6 to 30 carbon atoms.

[0018] Examples of heterocyclic groups include, but are not limited to, pyridyl, pyrimidyl, pyrazyl, triazyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazolyl, acridinyl, phenanthrolyl, and thienyl. Preferred heterocyclic groups are those having 3 to 27 carbon atoms.

[0019] Examples of substituents that may be further substituted by the alkyl group, silyl group, aryl group, and heterocyclic group include, but are not limited to, deuterium, alkyl groups such as methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, and tertiary butyl group, aralkyl groups such as benzyl group, aryl groups such as phenyl group and biphenyl group, halogen atoms such as fluorine, chlorine, bromine, and iodine, and thiol groups.

[0020] <r3> R3 is independently selected from a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group, and l represents an integer of 0 to 8. When l is 2 or more, multiple R3s may be the same or different.

[0021] Examples of halogen atoms include, but are not limited to, fluorine, chlorine, bromine, and iodine.

[0022] Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, isopropyloxy, tertiary butoxy, etc. Preferred alkoxy groups are those having 1 to 10 carbon atoms.

[0023] Specific examples of the alkyl group, silyl group, aryl group, and heterocyclic group include, but are not limited to, those described for R1 and R2. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms. The aryl group is preferably an aryl group having 6 to 30 carbon atoms. The heterocyclic group is preferably a heterocyclic group having 3 to 27 carbon atoms.

[0024] Specific examples of the substituents that the alkyl group, alkoxy group, silyl group, aryl group, and heterocyclic group may further have include, but are not limited to, those described for R1 and R2.

[0025] <m,n> m represents an integer of 1 or more and 3 or less, and n represents an integer of 0 or more and 2 or less, provided that m+n is 3. When m is 2 or more, the multiple ligands present may be the same or different. When n is 2, the multiple Xs present may be the same or different.

[0026] <x> X represents a bidentate ligand, and the partial structure IrX is either of the structures shown in the following general formula [2] or [3], where Ir is iridium.

[0027] [ka]

[0028] [R9 to R 19 ] In formula [2] or [3], R9 to R 19 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group.

[0029] R9 to R 19 Specific examples of the halogen atom, alkyl group, alkoxy group, silyl group, aryl group, and heterocyclic group represented by the formula (I) include, but are not limited to, those described for R3. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms. The alkoxy group is preferably an alkoxy group having 1 to 10 carbon atoms. The aryl group is preferably an aryl group having 6 to 30 carbon atoms. The heterocyclic group is preferably a heterocyclic group having 3 to 27 carbon atoms. Specific examples of substituents that the alkyl group, alkoxy group, silyl group, aryl group, and heterocyclic group may further have include, but are not limited to, those described for R3.

[0030] Also, adjacent R 16 ~R 19 may be bonded to each other to form a ring. 16 ~R 19 are bonded to each other to form a ring, R 16 and R 17 , R 17 and R 18 , R 18 and R 19 and a ring formed by bonding R 16 ~R 19 This means that the benzene ring to which the R is attached forms a condensed ring. 16 ~R 19 The ring formed by bonding may be an aromatic ring.

[0031] Ring A is any of the structures shown in the following general formulas [4] to [7].

[0032] [ka]

[0033] [R 20 ~R 29 ] In formulas [4] to [7], R 20 ~R 29 are each independently selected from a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 20 ~R 29 At least one of these is preferably a tertiary alkyl group, and the tertiary alkyl group is preferably a tertiary butyl group.

[0034] R 20 ~R 29 Specific examples of the halogen atom, alkyl group, alkoxy group, silyl group, aryl group, and heterocyclic group represented by the formula (I) include, but are not limited to, those described for R3. The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms. The alkoxy group is preferably an alkoxy group having 1 to 10 carbon atoms. The aryl group is preferably an aryl group having 6 to 30 carbon atoms. The heterocyclic group is preferably a heterocyclic group having 3 to 27 carbon atoms. Specific examples of substituents that the alkyl group, alkoxy group, silyl group, aryl group, and heterocyclic group may further have include, but are not limited to, those described for R3.

[0035] The organic compound of this embodiment is preferably represented by the following general formula

[10] .

[0036] [ka]

[0037] The organic compound of this embodiment is preferably represented by the following general formula

[11] .

[0038] [ka]

[0039] The organic compound of this embodiment has the following characteristics. (1-1) The presence of a benzofluorene ring in the ligand results in a high degree of orientation of the complex and a high luminescence quantum yield. (1-2) It has a low sublimation temperature and is less likely to decompose during sublimation purification. (1-3) The presence of a benzofluorene ring in the ligand provides high hole transport properties. This is explained below.

[0040] (1-1) The presence of a benzofluorene ring in the ligand results in a high degree of orientation of the complex and a high luminescence quantum yield.

[0041] The organic compound of this embodiment has a high luminescence quantum yield. In inventing the organometallic complex, we focused on the structure of the ligand of the organometallic complex. Specifically, we attempted to improve the quantum yield by using a benzofluorene skeleton for the aromatic ring of the aromatic ring and heterocyclic ring that make up the ligand of the Ir complex.

[0042] Here, the results of comparing the emission quantum yields of Compound 1 (exemplary compound D-1 described later) and Comparative Compound 1 are shown in Table 1. The quantum yield was measured by measuring the absolute quantum yield in a diluted toluene solution using an absolute PL quantum yield measurement apparatus (C9920-02) manufactured by Hamamatsu Photonics KK The quantum yield is expressed as a relative value, with the quantum yield of Compound 1 being set to 1.0.

[0043] [Table 1]

[0044] Table 1 shows that compound 1 has a higher quantum yield and better light-emitting properties than comparative compounds 1 and 2. Therefore, compound 1 has better light-emitting efficiency than comparative compounds 1 and 2 when used in the light-emitting layer of an organic light-emitting device.

[0045] The compound of this embodiment has a benzofluorene ring in the ligand, and it is believed that the condensation of one more benzene ring compared to the fluorene ring in the ligand of the comparative compound increases the transition dipole moment and improves the luminescence quantum yield.

[0046] (1-2) It has a low sublimation temperature and is less likely to decompose during sublimation purification.

[0047] As described in (1-1), the compound of this embodiment is characterized by a high quantum yield due to the presence of a benzofluorene ring in the ligand. The inventors also investigated ligands having a ring in which a benzene ring is further condensed, such as a naphthofluorene ring. However, it was found that compounds having a naphthofluorene ring in which a benzene ring is further condensed in the ligand, decompose during sublimation purification, as shown below.

[0048] Table 2 shows the sublimation temperature during the sublimation purification of each material and the presence or absence of decomposition peaks in HPLC of the material obtained after the sublimation purification. The degree of vacuum during the sublimation purification was 1 x 10 -3 From 1×10 -2 It is Pa.

[0049] [Table 2]

[0050] These results show that comparative compound 3 has a high sublimation temperature and is decomposed by sublimation purification. It is thought that the sublimation temperature increased significantly due to an increase in molecular weight caused by further condensation of the benzene rings, an increase in the planarity of the ligands, and an increase in the stacking of the complexes.

[0051] On the other hand, it was found that Compound 1 has a low sublimation temperature due to the suppression of stacking between complexes to some extent. Therefore, decomposition is unlikely to occur even when subjected to sublimation purification. Since the purity can be increased by sublimation purification, the use of Compound 1 can improve the luminous efficiency and driving durability of organic light-emitting devices. Therefore, Compound 1 has superior luminous efficiency to Comparative Compound 3 when used in the luminescent layer of an organic light-emitting device.

[0052] (1-3) The presence of a benzofluorene ring in the ligand provides high hole transport properties.

[0053] The organic compound of this embodiment has a high hole transport property due to the presence of benzofluorene rings in the ligands, which is thought to be due to a structure in which the benzofluorene rings of the ligands easily overlap with each other, facilitating hole hopping between the ligands.

[0054] Furthermore, the compound of this embodiment preferably has the following characteristics. (1-4) In the case of a compound represented by the general formula

[11] , the half width of the emission spectrum is narrow and the emission exhibits high color purity. (1-5) R3, R 20 ~R 29 When at least one of the groups is a tertiary alkyl group, the sublimation property is improved. This is explained below.

[0055] (1-4) In the case of a compound represented by the general formula

[11] , the half width of the emission spectrum is narrow and the emission exhibits high color purity.

[0056] In the compound represented by general formula

[11] , ring A has the structure represented by formula [4] and is bonded to the 10-position of the benzofluorene ring. Therefore, as shown in Figure 1, R1 and R2, preferably alkyl groups, at the 11-position of the benzofluorene ring are positioned so that they sandwich the hydrogen atom of the pyridine ring. Because the hydrogen atom of the pyridine ring repels the R1 and R2, particularly the alkyl groups, of the benzofluorene rings on both sides, the dihedral angle between the pyridine ring and the benzofluorene ring is fixed, the rotational energy of the two rings is very high, and rotation of the bond between the pyridine ring and the benzofluorene ring is suppressed. As a result, vibrational modes due to rotational control are suppressed in the emission spectrum, the half-width of the emission spectrum is narrowed, and color purity is high.

[0057] [ka]

[0058] (1-5) R3, R 20 ~R 29 When at least one of the groups is a tertiary alkyl group, the sublimation property is improved.

[0059] The organic compound of this embodiment has the above-mentioned characteristics due to the presence of a benzofluorene ring in the ligand, but the presence of a condensed polycyclic ring may result in a large molecular weight of the complex, which may cause poor sublimation. Specifically, the temperature during sublimation purification may be high, or the complex may be partially decomposed after sublimation purification. Therefore, it is necessary to select R3, R 20 ~R 29 At least one of the groups is preferably a tertiary alkyl group. This suppresses molecular stacking between complexes, lowering the sublimation temperature. When the tertiary alkyl group has four or more carbon atoms, it has a large effect of excluding complexes from each other and is highly effective in suppressing molecular stacking. By having a tertiary alkyl group, it is possible to reduce radical cleavage of hydrogen at the benzyl position due to temperature when subjected to high temperature loads.

[0060] Table 3 shows the bond dissociation energies of carbon-hydrogen bonds described in ACC. Chem. Res. 36, 255-263, (2003).

[0061] [Table 3]

[0062] A larger bond dissociation energy value indicates a stronger bond, and a smaller value indicates a weaker bond. In other words, it can be seen that the carbon-hydrogen bond at the benzylic position is a weak bond. This is because when the hydrogen atom at the benzylic position is eliminated to form a radical, the radical is stabilized by resonance with the π electrons of the adjacent benzene ring. For this reason, the carbon-hydrogen bond at the benzylic position is a weak bond. In other words, if a structure such as a benzyl group is not present in the molecular structure, the compound will have a carbon-hydrogen bond that is less likely to be broken, which is preferable.

[0063] Furthermore, the organic compound of this embodiment has a high hole transport property due to the presence of a benzofluorene ring in the ligand. This is thought to be due to the structure in which the benzofluorene rings of the ligands tend to overlap with each other, making it easy for holes to hop between the ligands. Therefore, in order to prevent the overlapping of the benzofluorene rings from decreasing, the ring A side, i.e., R 20 ~R 29 It is more preferable that at least one of them is a tertiary alkyl group.

[0064] <Example> Specific examples of the organic compound of this embodiment are shown below, but of course, are not limited to these. (D-7,8,9,15,19, E-8,9,15,19, F-7,8,10,12,15,19, G-7,8,19, H-4,5,8,18,19, I-3,7,8,10,12,19, K-14, L-8,15 are examples) .

[0065] [ka]

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] The example compounds in Group D are compounds with two pyridine ring-bonded ligands at the 10-position of the benzofluorene ring. The two highly planar benzofluorene rings enhance hole mobility and the high degree of orientation of the compound, improving the light extraction efficiency of the light-emitting device. Furthermore, as mentioned in (1-4), the half-width of the emission spectrum is narrow.

[0075] The exemplary compounds belonging to Group E are compounds having two ligands in which a pyridine ring is bonded to the 9-position of the benzofluorene ring. The presence of two highly planar benzofluorene rings results in high hole mobility and a high degree of orientation of the compound, improving the light extraction of the light-emitting device. Furthermore, compared to compounds having a ligand in which a pyridine ring is bonded to the 10- or 8-position of the benzofluorene ring, these compounds have the characteristic of longer emission wavelengths. Compared to compounds having a ligand in which a pyridine ring is bonded to the 10-position of the benzofluorene ring, these compounds have a broader emission spectrum, making them suitable for use as yellow-green or yellow-emitting dopants in two-color white light-emitting devices.

[0076] The example compounds in Group F are compounds with two pyridine ring-bonded ligands at the 8th position of the benzofluorene ring. The presence of two highly planar benzofluorene rings results in high hole mobility and a high degree of orientation of the compound, improving the light extraction of the light-emitting device. Compared to compounds with a pyridine ring-bonded ligand at the 10th position of the benzofluorene ring, the emission spectrum is broader, making them suitable for use as yellow-green or yellow-emitting dopants in two-color white light-emitting devices.

[0077] The example compounds in Group G are compounds with one ligand in which a pyridine ring is bonded to the 10-position of the benzofluorene ring. Because the molecular weight of the complex is small, the sublimation temperature and evaporation temperature are low. In addition, as mentioned in (1-4), the half-width of the emission spectrum is narrow.

[0078] The example compounds belonging to Group H are compounds having one ligand in which a pyridine ring is bonded to the 9-position of the benzofluorene ring. Because the molecular weight of the complex is small, the sublimation temperature and deposition temperature are low. In addition, compared to compounds having a ligand in which a pyridine ring is bonded to the 10- or 8-position of the benzofluorene ring, they have the characteristic of having a longer emission wavelength. Because the emission spectrum is broader than that of compounds having a ligand in which a pyridine ring is bonded to the 10-position of the benzofluorene ring, they can be used as yellow-green or yellow-emitting dopants in two-color white light-emitting devices.

[0079] The example compounds in Group I are compounds with one ligand in which a pyridine ring is bonded to the 8th position of the benzofluorene ring. The presence of one highly planar benzofluorene ring results in high hole mobility and a high degree of orientation of the compound, improving the light extraction of the light-emitting device. Compared to compounds with a ligand in which a pyridine ring is bonded to the 10th position of the benzofluorene ring, the emission spectrum is broader, making them suitable for use as yellow-green or yellow-emitting dopants in two-color white light-emitting devices.

[0080] The example compounds in Group J are compounds with three ligands, each of which has a pyridine ring bonded to a benzofluorene ring. The three highly planar benzofluorene rings provide high hole mobility and a high degree of orientation of the compound, improving the light extraction of the light-emitting device.

[0081] The example compounds belonging to groups K and L are compounds having a ligand in which a pyrimidine ring, oxazole ring, or thiazole ring is bonded to a benzofluorene ring. The presence of a pyrimidine ring with strong electron-withdrawing properties results in a compound with a low LUMO (lowest unoccupied molecular orbital) level (far from the vacuum level). Therefore, when used as an emitting dopant in an emitting layer, they are characterized by their ease of trapping electrons and excellent balance of electron and hole injection and movement in the emitting layer.

[0082] <Organic light-emitting element> The organic light-emitting element of this embodiment has at least a pair of electrodes, an anode and a cathode, and an organic compound layer disposed between these electrodes. In the organic light-emitting element of this embodiment, the organic compound layer may be a single layer or a laminate consisting of multiple layers, as long as it has a light-emitting layer. When the organic compound layer is a laminate consisting of multiple layers, the organic compound layer may have, in addition to the light-emitting layer, a hole injection layer, a hole transport layer, an electron blocking layer, a hole / exciton blocking layer, an electron transport layer, an electron injection layer, etc. Furthermore, the light-emitting layer may be a single layer or a laminate consisting of multiple layers.

[0083] In the organic light-emitting device of this embodiment, the organic compound according to this embodiment is contained in at least one of the organic compound layers. Specifically, the organic compound according to this embodiment is contained in any of the above-mentioned light-emitting layer, hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole / exciton blocking layer, electron transport layer, electron injection layer, etc. The organic compound according to this embodiment is preferably contained in the light-emitting layer.

[0084] In the organic light-emitting device of this embodiment, when the organic compound according to this embodiment is contained in the light-emitting layer, the light-emitting layer may be a layer consisting only of the organic compound according to this embodiment, or may be a layer consisting of the organic compound according to this embodiment and other compounds. Here, when the light-emitting layer is a layer consisting of the organic compound according to this embodiment and other compounds, the organic compound according to this embodiment may be used as a host of the light-emitting layer, or as a guest (dopant). It may also be used as an assist material that can be contained in the light-emitting layer.

[0085] Here, the host is the compound with the largest mass ratio among the compounds constituting the light-emitting layer. The guest is the compound with a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and is the compound that is primarily responsible for emitting light. The assist material is the compound with a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and has the function of assisting carrier injection and transport of electrons and holes.

[0086] Here, the concentration of the guest in the organic light-emitting device according to this embodiment is preferably 0.01% by mass to 30% by mass, more preferably 2% by mass to 20% by mass, based on the entire light-emitting layer.

[0087] The concentration of the assist material in the organic light-emitting element according to this embodiment is preferably 0.1% by mass or more and 45% by mass or less, and more preferably 5% by mass or more and 40% by mass or less, based on the entire light-emitting layer.

[0088] The present inventors have conducted various studies and found that when the organic compound according to this embodiment is used as a host, guest, or assist material in the light-emitting layer, particularly as a guest in the light-emitting layer, a device exhibiting high-efficiency, high-brightness light output and extremely high durability can be obtained. Furthermore, when the organic compound is used as an assist material in the light-emitting layer, a device exhibiting high-efficiency, high-brightness light output and extremely high durability can be obtained. This light-emitting layer may be a single layer or multiple layers, and may contain multiple light-emitting materials. A multiple layer may mean a state in which the light-emitting layer is stacked with another light-emitting layer, or an intermediate layer may be stacked between multiple light-emitting layers. Tandem elements or stacked elements may also be used. In these cases, the emitted color of the organic light-emitting device is not limited to a single color. More specifically, it may be white or an intermediate color.

[0089] The film is formed by vapor deposition or coating, the details of which will be explained in detail in the examples below.

[0090] The organic compound according to this embodiment can be used as a constituent material of an organic compound layer other than the light-emitting layer that constitutes the organic light-emitting device of this embodiment, specifically, 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.

[0091] When the compound represented by the general formula [1] is contained in the light-emitting layer, the following characteristics are obtained. (2-1) By including the compound represented by the general formula [1] as a guest material in the light-emitting layer, the interaction with the host material is strong, and energy transfer is easy. (2-2) The effect of (2-1) above is to promote the transport hopping of holes between the guest and the host, thereby improving the hole transportability in the light-emitting layer. This is explained below.

[0092] (2-1) By including the compound represented by the general formula [1] as a guest material in the light-emitting layer, the interaction with the host material is strong, and energy transfer is easy.

[0093] The compound represented by general formula [1] has a benzofluorene ring, a fused polycyclic ring composed of hydrocarbons with four fused rings, as a ligand. On the other hand, the host material is preferably a hydrocarbon, and more preferably a fused polycyclic compound. Because the compound represented by general formula [1] has a fused ring structure with low polarity and aromaticity as a ligand, a hydrocarbon, preferably a fused polycyclic group, is also introduced into the host. This facilitates ππ interactions between the host and guest ligands, facilitating energy transfer from the host.

[0094] It is known that triplet energy used in phosphorescent light-emitting devices undergoes energy transfer via the Dexter mechanism. The Dexter mechanism involves energy transfer through molecular contact. In other words, shortening the intermolecular distance between the host and guest materials allows for efficient energy transfer from the host to the guest material. The compound represented by general formula [1] has a fused ring structure in the ligand that is low in polarity and aromatic. Therefore, a hydrocarbon, preferably a hydrocarbon-based fused ring structure, is introduced into the host to facilitate ππ interactions between the host and guest ligands, facilitating energy transfer from the host.

[0095] The above effects are due to the fact that triplet excitons generated in the host material are quickly consumed for light emission, resulting in highly efficient light-emitting organic light-emitting devices. Furthermore, material degradation due to high-energy triplet excited states caused by further excitation of triplet excitons not used for light emission can be reduced, resulting in good driving durability of the organic light-emitting devices.

[0096] (2-2) The effect of (2-1) above is to promote the transport hopping of holes between the guest and the host, thereby improving the hole transportability in the light-emitting layer.

[0097] The iridium complex represented by general formula [1] has a benzofluorene ring in the ligand, resulting in a low HOMO (highest occupied molecular orbital) level (close to the vacuum level), and therefore a lower HOMO level than the host material. Holes injected from the hole-transport layer are transported by the host material, but the holes are transported by repeatedly trapping and detrapping between the iridium complex (guest) and the host. In this case, it is preferable for the host material and the iridium complex to have similar skeletons. In this case, the fused rings of the host and iridium complex overlap strongly, allowing for efficient hole transfer between the iridium complex and the host material. This suppresses voltage rise in the light-emitting layer, providing an organic light-emitting device with good driving durability at low voltages.

[0098] Furthermore, the organic light-emitting device of this embodiment preferably has the following features. (2-3) The light-emitting layer contains an assist material, and the LUMO level of the assist material is preferably lower than that of the host material (farther from the vacuum level), thereby confining both electron and hole carriers in the light-emitting layer and providing a highly efficient device. (2-4) The effect of (2-3) above reduces the injection of carriers into the adjacent transport layer through the light-emitting layer, thereby reducing the deterioration of the transport layer, thereby providing a highly durable element. This is explained below.

[0099] (2-3) The light-emitting layer contains an assist material, and the LUMO level of the assist material is preferably lower than that of the host material (farther from the vacuum level), thereby confining both electron and hole carriers in the light-emitting layer and providing a highly efficient device.

[0100] The iridium complex of this embodiment promotes hole injection into the light-emitting layer, so it is preferable to increase efficiency by injecting electrons and holes into the light-emitting layer in a balanced manner, and it is preferable to promote injection of electrons into the light-emitting layer. Hydrocarbon compounds preferred as host materials tend to have wide band gaps. Therefore, their LUMO levels are high (close to the vacuum level), which may make it difficult to inject electrons from the electron transport layer or hole blocking layer. Therefore, to facilitate electron injection into the light-emitting layer, it is preferable to further contain an assist material. Furthermore, it is preferable that the LUMO level of the assist material is lower than the LUMO level of the host material. This improves the injection of both holes and electrons into the light-emitting layer, maintaining carrier balance in the light-emitting layer and providing a highly efficient light-emitting device.

[0101] (2-4) The effect of (2-3) above reduces the injection of carriers into the adjacent transport layer through the light-emitting layer, thereby reducing the deterioration of the transport layer, thereby providing a highly durable element.

[0102] As described above, in the device of this embodiment, the iridium complex of this embodiment promotes hole injection in the light-emitting layer and exhibits the effect of trapping holes in the light-emitting layer, thereby reducing the injection of holes from the light-emitting layer into the hole-blocking layer and the electron-transporting layer and reducing the deterioration of the hole-blocking layer and the electron-transporting layer due to holes.

[0103] In addition, the assist material, which has a lower LUMO level than the host material, promotes electron injection and traps electrons in the light-emitting layer, reducing the injection of electrons from the light-emitting layer into the electron blocking layer and hole transport layer, and reducing the deterioration of the electron blocking layer and hole transport layer due to electrons.

[0104] <Host material> The host material is preferably a hydrocarbon. Furthermore, the host material preferably has a higher T1 (lowest triplet excitation energy) than the iridium complex represented by general formula [1]. Specifically, since the iridium complex of this embodiment emits light in the 500 nm to 600 nm region, the T1 of the host material is preferably 2.2 eV or more, more preferably 2.5 eV or more. Furthermore, as described above, in order to enhance the interaction with the benzofluorene ring of the ligand of the iridium complex, the host material is preferably a fused polycyclic compound. Specifically, examples of fused polycyclic groups having a T1 of 2.2 eV or more include fluoranthene, benzo[e]pyrene, benzo[g]chrysene, benzo[c]chrysene, coronene, benzofluorene, chrysene, picene, naphthalene, phenanthrene, triphenylene, and fluorene. Preferred are chrysene, picene, naphthalene, phenanthrene, triphenylene, and fluorene, each of which has a T1 of 2.5 eV or more.

[0105] Furthermore, the host material preferably has the following characteristics: (3-1) The skeleton has at least one of a chrysene ring, a picene ring, a phenanthrene ring, a triphenylene ring, and a fluorene ring. (3-2)SP 3 It has no carbon. The above will be explained below.

[0106] (3-1) The skeleton has at least one of a chrysene ring, a picene ring, a phenanthrene ring, a triphenylene ring, and a fluorene ring.

[0107] The compound of this embodiment has a benzofluorene skeleton in the ligand. The benzofluorene skeleton has a highly planar structure. In order for the iridium complex of this embodiment and the host material to interact as described above in (2-1) and (2-2), it is preferable that the host material also have a highly planar structure. This is because a highly planar structure allows highly planar moieties to approach each other through interaction. More specifically, the benzofluorene moiety of the iridium complex and the planar moiety of the host material are more likely to approach each other. This is expected to shorten the intermolecular distance between the iridium complex and the host material. The above effects lead to the effect of increasing the efficiency of energy transfer described in (2-1).

[0108] Here, examples of highly planar structures include structures containing fused polycyclic rings of three or more rings, and preferred are structures containing fused polycyclic hydrocarbon rings such as chrysene rings, picene rings, phenanthrene rings, triphenylene rings, and fluorene rings, which are fused polycyclic rings having a T1 of 2.5 eV or more.

[0109] (3-2)SP 3 It has no carbon.

[0110] As described in the above explanation (3-1), the compound of this embodiment is a compound characterized in that the interaction and luminescence properties are improved by improving the distance from the host material. 3 By using a material that does not contain carbon, the distance to the iridium complex, which is the guest material, can be shortened.

[0111] [Specific example] Specific examples of the host material are shown below, but the present invention is not limited to these.

[0112] [ka]

[0113] [ka]

[0114] The exemplary host compounds include those having at least one of a triphenylene ring, a naphthalene ring, a phenanthrene ring, a chrysene ring, and a fluorene ring in the skeleton, and having the structure of SP 3 These compounds do not contain carbon. Therefore, these compounds can be closer to the compound of this embodiment, so they have a strong interaction and are host materials that transfer energy well to the compound of this embodiment. Among these, compounds having a triphenylene ring in the skeleton are particularly preferred because they have high planarity.

[0115] <Assist materials> The light-emitting layer preferably further contains an assist material, which is preferably a compound partially having any one of the following structures:

[0116] [ka]

[0117] (In the above structure, X' represents an oxygen atom, a sulfur atom, or a substituted or unsubstituted carbon atom.)

[0118] The above structure is effective because it has electron-withdrawing properties and can lower the LUMO level of the assist material. The iridium complex represented by general formula [1] has a high HOMO level and therefore tends to trap holes easily, while its high LUMO level makes it difficult to trap electrons. Therefore, by including an assist material with a low LUMO level in the light-emitting layer, electrons can be trapped in the light-emitting layer, providing a device with an appropriate carrier balance, resulting in high efficiency and long life.

[0119] The above structure may be unsubstituted or substituted. The carbon atom represented by X' may be unsubstituted or substituted. Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an aryl group, a heterocyclic group, a silyl group, and an amino group.

[0120] Examples of halogen atoms include, but are not limited to, fluorine, chlorine, bromine, and iodine.

[0121] Examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, a normal propyl group, an isopropyl group, a normal butyl group, a tertiary butyl group, a secondary butyl group, an octyl group, a cyclohexyl group, a 1-adamantyl group, and a 2-adamantyl group.

[0122] Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, 2-ethyl-octyloxy, and benzyloxy groups.

[0123] Examples of the aryloxy group include, but are not limited to, a phenoxy group and a naphthoxy group.

[0124] Examples of heteroaryloxy groups include, but are not limited to, furanyloxy groups and thienyloxy groups.

[0125] Examples of aryl groups include, but are not limited to, phenyl, naphthyl, indenyl, biphenyl, terphenyl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, anthranyl, perylenyl, chrysenyl, and fluoranthenyl groups.

[0126] Examples of heterocyclic groups include, but are not limited to, pyridyl, pyrimidyl, pyrazyl, triazyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazolyl, acridinyl, and phenanthrolyl groups.

[0127] Examples of the silyl group include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0128] Examples of the amino group include, but are not limited to, an N-methylamino group, an N-ethylamino group, an N,N-dimethylamino group, an N,N-diethylamino group, an N-methyl-N-ethylamino group, an N-benzylamino group, an N-methyl-N-benzylamino group, an N,N-dibenzylamino group, an anilino group, an N,N-diphenylamino group, an N,N-dinaphthylamino group, an N,N-difluorenylamino group, an N-phenyl-N-tolylamino group, an N,N-ditolylamino group, an N-methyl-N-phenylamino group, an N,N-dianisolylamino group, an N-mesityl-N-phenylamino group, an N,N-dimesitylamino group, an N-phenyl-N-(4-tert-butylphenyl)amino group, an N-phenyl-N-(4-trifluoromethylphenyl)amino group, an N-piperidyl group, a carbazolyl group, and an acridyl group.

[0129] Examples of substituents that the alkyl group, alkoxy group, aryloxy group, heteroaryloxy group, aryl group, heterocyclic group, silyl group, and amino 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 tertiary butyl group, aralkyl groups such as benzyl group, aryl groups such as phenyl group and biphenyl group, heterocyclic groups such as pyridyl group and pyrrolyl group, amino groups such as dimethylamino group, diethylamino group, dibenzylamino group, diphenylamino group, and ditolylamino group, alkoxy groups such as methoxy group, ethoxy group, and propoxy group, aryloxy groups such as phenoxy group, halogen atoms such as fluorine, chlorine, bromine, and iodine, and cyano group.

[0130] [Specific example] Specific examples of the assist material are shown below, but the material is not limited to these.

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] <Other ingredients> In addition to the organic compound according to this embodiment, the light-emitting device of this embodiment may also use, as needed, conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host compounds, light-emitting compounds, electron-injecting or electron-transporting compounds, etc. Examples of these compounds are listed below.

[0135] As the hole injection and transport material, a material with high hole mobility is preferred so that holes can be easily injected from the anode and the injected holes can be transported to the light-emitting layer. Furthermore, a material with a high glass transition temperature is preferred to suppress deterioration of film quality, such as crystallization, in organic light-emitting devices. Examples of low-molecular-weight and high-molecular-weight materials with hole injection and transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. Furthermore, the above-mentioned hole injection and transport materials are also suitable for use in electron blocking layers. Specific examples of compounds that can be used as hole injection and transport materials are listed below, but the present invention is not limited to these.

[0136] [ka]

[0137] Among the hole transport materials listed above, HT16 to HT18 can reduce the driving voltage when used in a layer in contact with the anode. HT16 is widely used in organic light-emitting devices. HT2 to HT6, HT10, and HT12 may be used in an organic compound layer adjacent to HT16. Furthermore, multiple materials may be used in one organic compound layer.

[0138] Examples of the light-emitting dopant include fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, anthracene derivatives, rubrene, etc.), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and polymer derivatives such as poly(phenylenevinylene) derivatives, poly(fluorene) derivatives, and poly(phenylene) derivatives. Specific examples of compounds that can be used as light-emitting materials are shown below, but the present invention is not limited to these.

[0139] [ka]

[0140] [ka]

[0141] When the light-emitting material is a hydrocarbon compound, it is preferable because it reduces the decrease in light-emitting efficiency due to exciplex formation and the deterioration in color purity due to changes in the light-emitting spectrum of the light-emitting material. Hydrocarbon compounds are compounds composed only of carbon and hydrogen, and correspond to BD7, BD8, GD5 to GD9, and RD1. Furthermore, when the light-emitting material is a fused polycyclic ring containing a five-membered ring, it is even more preferable because it has a high ionization potential, is resistant to oxidation, and provides an element with a long and durable lifespan. Corresponding examples include BD7, BD8, GD5 to GD9, and RD1.

[0142] Examples of host materials or assist materials include aromatic hydrocarbon compounds or derivatives thereof, as well as carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, and organic beryllium complexes. Specific examples of the compounds are shown below, but are not limited to these.

[0143] [ka]

[0144] When the host material is a hydrocarbon compound, the compound of this embodiment is more likely to trap electrons and holes, which is preferable because it significantly improves efficiency. Hydrocarbon compounds are compounds composed only of carbon and hydrogen, and correspond to EM1 to EM12 and EM16 to EM27.

[0145] The electron transport material can be arbitrarily selected from those capable of transporting electrons injected from the cathode to the light-emitting layer, and is selected taking into consideration the balance with the hole mobility of the hole transport material. Examples of materials having electron transport properties include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organoaluminum complexes, and fused ring compounds (e.g., fluorene derivatives, naphthalene derivatives, chrysene derivatives, anthracene derivatives, etc.). Furthermore, the above electron transport materials are also suitable for use in hole-blocking layers. Specific examples of compounds used as electron transport materials are shown below, but of course, the present invention is not limited to these.

[0146] [ka]

[0147] The electron injection material can be selected from those that allow easy electron injection from the cathode, taking into consideration the balance with hole injection properties, etc. Organic compounds include n-type dopants and reducing dopants. Examples include compounds containing alkali metals such as lithium fluoride, lithium complexes such as lithium quinolinol, benzimidazolidene derivatives, imidazolidene derivatives, fulvalene derivatives, and acridine derivatives.

[0148] <Configuration of organic light-emitting element> The organic light-emitting element is provided by forming an insulating layer, a first electrode, an organic compound layer, and a second electrode on a substrate. A protective layer, a color filter, a microlens, etc. may be provided on the second electrode. When a color filter is provided, a planarizing layer may be provided between the color filter and the protective layer. The planarizing layer may be made of an acrylic resin, etc. The same applies when a planarizing layer is provided between the color filter and the microlens.

[0149] [substrate] Examples of the substrate include quartz, glass, a silicon wafer, a resin, and a metal. Furthermore, the substrate may be provided with a switching element such as a transistor and wiring, and an insulating layer thereon. Any material can be used for the insulating layer, as long as it allows for the formation of a contact hole so that wiring can be formed between the first electrode and the insulating layer, and ensures insulation from wiring that is not connected. For example, resins such as polyimide, silicon oxide, silicon nitride, etc. can be used.

[0150] [electrode] A pair of electrodes can be used. The pair of electrodes may be an anode and a cathode. When an electric field is applied in the direction in which the organic light-emitting element emits light, the electrode with a higher potential is the anode, and the other is the cathode. It can also be said that the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons is the cathode.

[0151] The anode material should have as high a work function as possible. Examples include simple metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten, mixtures containing these metals, alloys of these metals, and metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and zinc indium oxide. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0152] These electrode materials may be used alone or in combination of two or more. The anode may be composed of one layer or multiple layers.

[0153] When used as a reflective electrode, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, or alloys or laminates thereof can be used. The above materials can also function as a reflective film without functioning as an electrode. When used as a transparent electrode, transparent conductive oxide layers such as indium tin oxide (ITO) and indium zinc oxide can be used, but are not limited to these. Photolithography techniques can be used to form the electrode.

[0154] On the other hand, materials with a low work function are preferred for the cathode. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, and metals such as aluminum, titanium, manganese, silver, lead, and chromium, as well as mixtures containing these metals. Alternatively, alloys combining these metals can be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials can be used alone or in combination. The cathode can have either a single-layer or multi-layer structure. Among these, silver is preferred, and a silver alloy is even more preferred to reduce silver aggregation. The alloy ratio is not critical as long as silver aggregation can be reduced. For example, the silver:other metal ratio can be 1:1, 3:1, or the like.

[0155] The cathode may be a top-emission element using an oxide conductive layer such as ITO, or a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but DC and AC sputtering methods are more preferred because they provide good film coverage and make it easier to reduce resistance.

[0156] [Organic compound layer] The organic compound layer may be formed as a single layer or as multiple layers. When multiple layers are included, they may be called hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, or electron injection layer depending on their functions. The organic compound layer is mainly composed of organic compounds but may also contain inorganic atoms or inorganic compounds. For example, the organic compound layer may contain copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, or the like. The organic compound layer may be disposed between the first electrode and the second electrode, or may be disposed in contact with the first electrode and the second electrode.

[0157] The organic compound layers (hole injection layer, hole transport layer, electron blocking layer, light emitting layer, hole blocking layer, electron transport layer, electron injection layer, etc.) constituting the organic light emitting device according to one embodiment of the present invention are formed by the method shown below.

[0158] The organic compound layer constituting the organic light-emitting device according to one embodiment of the present invention can be formed by dry processes such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Alternatively to the dry process, a wet process can be used in which the compound is dissolved in an appropriate solvent and a layer is formed by a known coating method (for example, spin coating, dipping, casting, LB method, inkjet method, etc.).

[0159] Here, when a layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When a film is formed by a coating method, the film can be formed by combining with an appropriate binder resin.

[0160] Examples of the binder resin include, but are not limited to, polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0161] These binder resins may be used singly or in combination as homopolymers or copolymers, and may further contain known additives such as plasticizers, antioxidants, and ultraviolet absorbers, if necessary.

[0162] [Protective layer] A protective layer may be provided on the second electrode. For example, by adhering glass with a moisture absorbent on the second electrode, the infiltration of water and other contaminants into the organic compound layer can be reduced, thereby reducing the occurrence of display defects. In another embodiment, a passivation film such as silicon nitride may be provided on the second electrode to reduce the infiltration of water and other contaminants into the organic compound layer. For example, after forming the second electrode, the second electrode may be transferred to another chamber without breaking the vacuum, and a 2 μm-thick silicon nitride film may be formed by CVD to serve as a protective layer. A protective layer may be provided using atomic layer deposition (ALD) after the CVD film formation. The material of the film formed by ALD is not limited, and may be silicon nitride, silicon oxide, aluminum oxide, or the like. Silicon nitride may be further formed on the film formed by ALD by CVD. The film formed by ALD may have a thickness smaller than that of the film formed by CVD. Specifically, the thickness may be 50% or less, or even 10% or less.

[0163] [Color Filter] A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on a separate substrate and then bonded to the substrate on which the organic light-emitting element is provided, or a color filter may be patterned on the protective layer described above using photolithography technology. The color filter may be made of a polymer.

[0164] [Planarization layer] A planarization layer may be provided between the color filter and the protective layer. The planarization layer is provided for the purpose of reducing the unevenness of the underlying layer. It may also be called a material resin layer without limiting its purpose. The planarization layer may be composed of an organic compound, and may be either a low molecular weight or a high molecular weight, but a high molecular weight is preferred.

[0165] The planarizing layer may be provided above or below the color filter, and may be made of the same or different materials, such as polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0166] [Microlens] The organic light-emitting element or organic light-emitting device may have an optical component such as a microlens on its light-emitting side. The microlens may be made of acrylic resin, epoxy resin, or the like. The microlens may be intended to increase the amount of light extracted from the organic light-emitting element or organic light-emitting device or to control the direction of the extracted light. The microlens may have a hemispherical shape. When the microlens has a hemispherical shape, among the tangents to the hemisphere, there is a tangent that is parallel to the insulating layer, and the vertex of the microlens is the point of contact between this tangent and the hemisphere. The vertex of the microlens can be determined in the same way in any cross-sectional view. In other words, among the tangents to the semicircle of the microlens in the cross-sectional view, there is a tangent that is parallel to the insulating layer, and the vertex of the microlens is the point of contact between this tangent and the semicircle.

[0167] It is also possible to define the midpoint of a microlens. In the cross section of the microlens, a line segment is imagined from the point where an arc shape ends to the point where another arc shape ends, and the midpoint of this line segment can be called the midpoint of the microlens. The cross section for determining the vertex and midpoint may be a cross section perpendicular to the insulating layer.

[0168] [Counter substrate] An opposing substrate may be provided on the planarization layer. The opposing substrate is called an opposing substrate because it is provided at a position corresponding to the aforementioned substrate. The constituent material of the opposing substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate is defined as a first substrate, the opposing substrate may be a second substrate.

[0169] [Pixel circuit] An organic light-emitting device having an organic light-emitting element may have a pixel circuit connected to the organic light-emitting element. The pixel circuit may be an active matrix type that controls the emission of the first light-emitting element and the second light-emitting element independently. The active matrix type circuit may be voltage-programmed or current-programmed. The drive circuit has a pixel circuit for each pixel. The pixel circuit may have a light-emitting element, a transistor that controls the emission brightness of the light-emitting element, a transistor that controls the emission timing, a capacitor that holds the gate voltage of the transistor that controls the emission brightness, and a transistor for connecting to GND without going through the light-emitting element.

[0170] The light-emitting device has a display area and a peripheral area arranged around the display area. The display area has a pixel circuit, and the peripheral area has a display control circuit. The mobility of a transistor constituting the pixel circuit may be smaller than the mobility of a transistor constituting the display control circuit. The slope of the current-voltage characteristics of the transistor constituting the pixel circuit may be smaller than the slope of the current-voltage characteristics of the transistor constituting the display control circuit. The slope of the current-voltage characteristics can be measured by the so-called Vg-Ig characteristics. The transistor constituting the pixel circuit is a transistor connected to a light-emitting element, such as a first light-emitting element.

[0171] [Pixels] An organic light emitting device having an organic light emitting element may have a plurality of pixels, each of which has sub-pixels that emit different colors, for example, RGB colors.

[0172] A pixel emits light from an area called a pixel aperture. This area is the same as the first area. The pixel aperture may be 15 μm or less, or 5 μm or more. More specifically, it may be 11 μm, 9.5 μm, 7.4 μm, 6.4 μm, etc. The distance between subpixels may be 10 μm or less, more specifically, it may be 8 μm, 7.4 μm, or 6.4 μm.

[0173] The pixels may be arranged in a known manner in a plan view. For example, they may be in a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixels in a plan view may be any known shape. For example, they may be rectangular, quadrilaterals such as diamonds, or hexagons. Of course, a shape that is close to a rectangle, rather than an exact shape, is included in the rectangle. The shape of the subpixels and the pixel arrangement may be used in combination.

[0174] <Applications of organic light-emitting devices> The organic light-emitting device according to this embodiment can be used as a component of a display device or a lighting device, and can also be used as an exposure light source for an electrophotographic image forming device, a backlight for a liquid crystal display device, or a light-emitting device having a white light source and a color filter.

[0175] The display device may be an image information processing device that has an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., has an information processing unit that processes the input information, and displays the input image on a display unit. The display device may have a plurality of pixels, at least one of which may have the organic light-emitting element of this embodiment and a transistor connected to the organic light-emitting element.

[0176] The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of this touch panel function may be an infrared method, a capacitance method, a resistive film method, or an electromagnetic induction method, and is not particularly limited. The display device may also be used in the display unit of a multifunction printer.

[0177] Next, a display device according to this embodiment will be described with reference to the drawings. Fig. 2 is a cross-sectional view showing an example of a display device having an organic light-emitting element and a transistor connected to the organic light-emitting element. The transistor is an example of an active element. The transistor may be a thin-film transistor (TFT).

[0178] FIG. 2(a) shows an example of a pixel, which is a component of the display device according to this embodiment. The pixel includes sub-pixels 10. The sub-pixels are divided into 10R, 10G, and 10B based on their light emission. The emitted colors may be distinguished by the wavelength of light emitted from the light-emitting layer, or the light emitted from the sub-pixels may be selectively transmitted or color-converted using a color filter or the like. Each sub-pixel 10 includes a reflective electrode serving as a first electrode 2 on an interlayer insulating layer 1, an insulating layer 3 covering the edge of the first electrode 2, an organic compound layer 4 covering the first electrode 2 and the insulating layer 3, a transparent electrode serving as a second electrode 5, a protective layer 6, and a color filter 7.

[0179] A transistor and a capacitor element may be disposed below or inside the interlayer insulating layer 1. The transistor and the first electrode 2 may be electrically connected via a contact hole or the like (not shown).

[0180] The insulating layer 3 is also called a bank or a pixel separation film. It covers the edges of the first electrode 2 and is disposed to surround the first electrode 2. The portion where the insulating layer 3 is not disposed is in contact with the organic compound layer 4 and becomes a light-emitting region.

[0181] The organic compound layer 4 includes a hole injection layer 41 , a hole transport layer 42 , a first light-emitting layer 43 , a second light-emitting layer 44 , and an electron transport layer 45 .

[0182] The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0183] The protective layer 6 reduces the penetration of moisture into the organic compound layer 4. Although the protective layer 6 is illustrated as being one layer, it may be multiple layers, and each layer may be an inorganic compound layer and an organic compound layer.

[0184] The color filters 7 are divided into 7R, 7G, and 7B depending on their colors. The color filters 7 may be formed on a planarization film (not shown). A resin protective layer (not shown) may be provided on the color filters 7. The color filters 7 may be formed on a protective layer 6. Alternatively, the color filters 7 may be provided on an opposing substrate such as a glass substrate and then bonded thereto.

[0185] The display device 100 in FIG. 2(b) has an organic light-emitting element 26 and a TFT 18 as an example of a transistor. A substrate 11 made of glass, silicon, or the like is provided with an insulating layer 12 on top of it. An active element such as the TFT 18 is disposed on the insulating layer 12, and a gate electrode 13, a gate insulating film 14, and a semiconductor layer 15 of the active element are disposed on top of it. The TFT 18 also includes a drain electrode 16 and a source electrode 17. An insulating film 19 is provided on top of the TFT 18. An anode 21 constituting the organic light-emitting element 26 and the source electrode 17 are connected via a contact hole 20 provided in the insulating film 19.

[0186] The electrical connection method between the electrodes (anode 21, cathode 23) included in the organic light-emitting element 26 and the electrodes (source electrode 17, drain electrode 16) included in the TFT 18 is not limited to the embodiment shown in Fig. 2(b). In other words, it is sufficient that either the anode 21 or the cathode 23 is electrically connected to either the source electrode 17 or the drain electrode 16 of the TFT 18. TFT stands for thin film transistor.

[0187] 2(b), the organic compound layer 22 is illustrated as a single layer, but may be a multi-layer organic compound layer 22. A first protective layer 24 and a second protective layer 25 are provided on the cathode 23 to reduce deterioration of the organic light-emitting element 26.

[0188] In the display device 100 of FIG. 2(b), transistors are used as switching elements, but other switching elements may be used instead.

[0189] The transistors used in the display device 100 of Fig. 2(b) are not limited to transistors using single-crystal silicon wafers, but may also be thin-film transistors having an active layer on an insulating surface of a substrate. Examples of active layers include single-crystal silicon, amorphous silicon, microcrystalline silicon, and other non-single-crystal silicon, as well as non-single-crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide. Thin-film transistors are also called TFT elements.

[0190] The transistors included in the display device 100 of Fig. 2(b) may be formed within a substrate such as a Si substrate. Here, "formed within a substrate" means that the substrate itself, such as a Si substrate, is processed to form the transistors. In other words, having a transistor within a substrate can be seen as the substrate and the transistor being formed integrally.

[0191] The organic light-emitting element according to this embodiment has its emission brightness controlled by a TFT, which is an example of a switching element. By providing multiple organic light-emitting elements on a surface, an image can be displayed based on the emission brightness of each element. Note that the switching element according to this embodiment is not limited to a TFT, and may be a transistor formed from low-temperature polysilicon or an active matrix driver formed on a substrate such as a Si substrate. "On the substrate" can also be referred to as "inside the substrate." Whether to provide a transistor in the substrate or to use a TFT is determined by the size of the display unit. For example, for a display size of about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

[0192] 3 is a schematic diagram illustrating an example of a display device according to this embodiment. The display device 1000 may include a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The touch panel 1003 and the display panel 1005 are connected by flexible printed circuits FPCs 1002 and 1004. Transistors are printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position even if the display device is a portable device.

[0193] The display device according to this embodiment may have color filters having red, green, and blue colors, which may be arranged in a delta arrangement.

[0194] The display device according to the present embodiment may be used as a display unit of a mobile terminal. In this case, the display device may have both a display function and an operation function. Examples of the mobile terminal include a mobile phone such as a smartphone, a tablet, and a head-mounted display.

[0195] The display device according to this embodiment may be used as a display unit of an imaging device having an optical unit with a plurality of lenses and an imaging element that receives light that has passed through the optical unit. The imaging device may have a display unit that displays information acquired by the imaging element. The display unit may be a display unit exposed to the outside of the imaging device or a display unit disposed within a viewfinder. The imaging device may be a digital camera or a digital video camera.

[0196] 4A is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may include a display device according to this embodiment. In this case, the display device may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the speed at which the subject is moving, the possibility that the subject will be blocked by an obstruction, and the like.

[0197] Since the optimum timing for capturing an image is very short, it is better to display information as soon as possible. Therefore, it is preferable to use a display device using the organic light-emitting element of this embodiment. This is because the organic light-emitting element has a fast response speed. A display device using the organic light-emitting element can be used more preferably than a liquid crystal display device, which requires a high display speed.

[0198] The imaging device 1100 has an optical section (not shown). The optical section has multiple lenses, which form an image on an imaging element housed in a housing 1104. The focus of the multiple lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically. The imaging device may also be called a photoelectric conversion device. Instead of sequentially capturing images, the photoelectric conversion device can include an imaging method that detects the difference from the previous image, or a method of cutting out an image from a constantly recorded image, etc.

[0199] FIG. 4(b) is a schematic diagram illustrating an example of an electronic device according to this embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit 1202 may be a biometric recognition unit that recognizes a fingerprint to perform unlocking or the like. An electronic device having a communication unit can also be called a communication device. The electronic device 1200 may further have a camera function by including a lens and an image sensor. An image captured by the camera function is displayed on the display unit 1201. Examples of the electronic device 1200 include a smartphone and a laptop computer.

[0200] FIG. 5 is a schematic diagram illustrating an example of a display device according to this embodiment. FIG. 5(a) illustrates a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The display unit 1302 may use a light-emitting element according to this embodiment. The display device 1300 has the frame 1301 and a base 1303 that supports the display unit 1302. The base 1303 is not limited to the form shown in FIG. 5(a). The lower side of the frame 1301 may also serve as the base. The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0201] FIG. 5(b) is a schematic diagram illustrating another example of a display device according to this embodiment. The display device 1310 in FIG. 5(b) is configured to be bendable, and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 may include light-emitting elements according to this embodiment. The first display unit 1311 and the second display unit 1312 may be a single, seamless display unit. The first display unit 1311 and the second display unit 1312 can be separated by the bending point. The first display unit 1311 and the second display unit 1312 may each display different images, or the first and second display units may display a single image.

[0202] FIG. 6(a) is a schematic diagram illustrating an example of a lighting device according to this embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, a circuit board 1403, an optical filter 1404 that transmits light emitted by the light source 1402, and a light diffusion unit 1405. The light source 1402 may include an organic light-emitting element according to this embodiment. The optical filter 1404 may be a filter that improves the color rendering of the light source. The light diffusion unit 1405 can effectively diffuse light from the light source, such as for illumination, and deliver the light over a wide area. The optical filter 1404 and the light diffusion unit 1405 may be provided on the light emission side of the lighting. If necessary, a cover may be provided on the outermost surface.

[0203] The lighting device is, for example, a device that illuminates a room. The lighting device may emit white, daylight white, or any other color from blue to red. It may have a dimming circuit that dims these colors. The lighting device may have the organic light-emitting element of this embodiment and a power supply circuit connected thereto. The power supply circuit is a circuit that converts AC voltage to DC voltage. Furthermore, white has a color temperature of 4200K, and daylight white has a color temperature of 5000K. The lighting device may have a color filter.

[0204] The lighting device according to this embodiment may also include a heat dissipation unit, which dissipates heat from within the device to the outside, and may be made of a material such as a metal with a high specific heat capacity or liquid silicon.

[0205] 6(b) is a schematic diagram of an automobile, which is an example of a moving body according to this embodiment. The automobile has tail lamps, which are an example of lighting fixtures. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking or the like is performed.

[0206] The tail lamp 1501 may include an organic light-emitting element according to this embodiment. The tail lamp 1501 may include a protective member for protecting the organic light-emitting element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0207] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window 1502 may be a transparent display as long as it is not a window for checking the front and rear of the automobile. The transparent display may have an organic light-emitting element according to this embodiment. In this case, the constituent materials of the electrodes and the like of the organic light-emitting element are made of transparent materials.

[0208] The moving body according to this embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lighting device provided on the body. The lighting device may emit light to indicate the position of the body. The lighting device has the organic light-emitting element according to this embodiment.

[0209] An application example of the display device of each of the above-described embodiments will be described with reference to Fig. 7. The display device can be applied to a system that can be attached as a wearable device, such as smart glasses, an HMD, or a smart contact lens. The image capturing and display device used in such an application example includes an image capturing device capable of photoelectrically converting visible light and a display device capable of emitting visible light.

[0210] Fig. 7(a) is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention. Using Fig. 7(a), glasses 1600 (smart glasses) according to one application example will be described. An imaging device 1602 such as a CMOS sensor or SPAD is provided on the front side of a lens 1601 of the glasses 1600. In addition, a display device according to each of the above-mentioned embodiments is provided on the back side of the lens 1601.

[0211] The glasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the image capture device 1602 and the display device. The control device 1603 also controls the operations of the image capture device 1602 and the display device. The lens 1601 is formed with an optical system for focusing light onto the image capture device 1602.

[0212] FIG. 7(b) is a schematic diagram showing another example of a wearable device according to an embodiment of the present invention. Using FIG. 7(b), glasses 1610 (smart glasses) according to one application example will be described. The glasses 1610 have a control device 1612, which is equipped with an imaging device corresponding to the imaging device 1602 in FIG. 7(a) and a display device. A lens 1611 is formed with an optical system for projecting light emitted from the imaging device in the control device 1612 and the display device, and an image is projected onto the lens 1611. The control device 1612 functions as a power source that supplies power to the imaging device and the display device, and also controls the operation of the imaging device and the display device.

[0213] The control device 1612 may include a gaze detection unit that detects the wearer's gaze. The gaze detection may use infrared light. The infrared light emitter emits infrared light toward the eyeball of the user gazing at the display image. An imaging unit with a light-receiving element detects the reflected infrared light from the eyeball, thereby obtaining a captured image of the eyeball. A reduction unit that reduces light from the infrared light emitter to the display unit in a planar view reduces degradation of image quality. The user's gaze toward the displayed image is detected from the captured image of the eyeball obtained by capturing infrared light. Any known method can be applied to gaze detection using the captured image of the eyeball. As an example, a gaze detection method based on a Purkinje image formed by reflection of irradiated light on the cornea can be used. More specifically, gaze detection processing based on the pupil-corneal reflex method is performed. Using the pupil-corneal reflex method, a gaze vector representing the orientation (rotation angle) of the eyeball is calculated based on the image of the pupil and the Purkinje image included in the captured image of the eyeball, thereby detecting the user's gaze.

[0214] A display device according to one embodiment of the present invention may include an imaging device having a light receiving element, and may control the display image of the display device based on user line-of-sight information from the imaging device. Specifically, the display device determines a first field of view area where the user gazes and a second field of view area other than the first field of view area based on the line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. In the display area of ​​the display device, the display resolution of the first field of view area may be controlled to be higher than the display resolution of the second field of view area. In other words, the resolution of the second field of view area may be lower than that of the first field of view area.

[0215] The display area includes a first display area and a second display area different from the first display area, and a high-priority area is determined from the first display area and the second display area based on line-of-sight information. The first field of view area and the second field of view area may be determined by a control device of the display device, or may be determined by an external control device and received. The resolution of the high-priority area may be controlled to be higher than the resolution of areas other than the high-priority area. In other words, the resolution of an area with a relatively low priority may be lowered.

[0216] Note that AI may be used to determine the first field of view area and areas with high priority. The AI ​​may be a model configured to estimate the angle of gaze and the distance to an object in the line of sight from an image of the eyeball, using as training data an image of the eyeball and the direction in which the eyeball in the image was actually looking. The AI ​​program may be included in the display device, the imaging device, or an external device. If included in an external device, it is transmitted to the display device via communication.

[0217] When display control is performed based on visual recognition detection, the smart glasses can be preferably applied to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured external information in real time.

[0218] 8(a) is a schematic diagram showing an example of an image forming apparatus according to one embodiment of the present invention. The image forming apparatus 40 is an electrophotographic image forming apparatus and includes a photoconductor 27, an exposure light source 28, a charging unit 30, a developing unit 31, a transfer unit 32, a transport roller 33, and a fixing unit 35. Light 29 is irradiated from the exposure light source 28, and an electrostatic latent image is formed on the surface of the photoconductor 27. The exposure light source 28 includes the organic light-emitting element according to this embodiment. The developing unit 31 includes toner and the like. The charging unit 30 charges the photoconductor 27. The transfer unit 32 transfers the developed image to a recording medium 34. The transport roller 33 transports the recording medium 34. The recording medium 34 is, for example, paper. The fixing unit 35 fixes the image formed on the recording medium 34.

[0219] 8(b) and 8(c) are diagrams showing an exposure light source 28 and are schematic diagrams illustrating a state in which multiple light-emitting units 36 are arranged on a long substrate. Arrow 37 indicates the direction parallel to the axis of the photoconductor, the column direction in which the organic light-emitting elements are arranged. This column direction is the same as the axis direction about which the photoconductor 27 rotates. This direction can also be referred to as the long axis direction of the photoconductor 27. FIG. 8(b) shows a configuration in which the light-emitting units 36 are arranged along the long axis direction of the photoconductor 27. FIG. 8(c) shows a configuration different from FIG. 8(b), in which the light-emitting units 36 are arranged alternately in the column direction in the first and second columns. The first and second columns are arranged at different positions in the row direction. In the first column, multiple light-emitting units 36 are arranged at intervals. In the second column, light-emitting units 36 are located at positions corresponding to the intervals between the light-emitting units 36 in the first column. In other words, multiple light-emitting units 36 are also arranged at intervals in the row direction. The arrangement in FIG. 8(c) can also be described as a grid arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0220] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to provide a stable display with good image quality even over a long period of time. [Example]

[0221] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0222] [Example 1 (Synthesis of Exemplary Compound D-1)] Exemplary compound D-1 was synthesized according to the following scheme. [ka]

[0223] (1) Synthesis of compound f-3 The following reagents and solvents were placed in a 200 ml recovery flask. Compound f-1: 6.46g (20.0mmol) Sodium carbonate: 5.3 g (50.0 mmol) THF: 90ml Water: 35ml Ethanol: 10ml Next, the reaction solution was cooled to -78°C, and 16.0 ml (25.0 mmol) of n-BuLi (1.56 M hexane solution) was added dropwise. After stirring for 30 minutes, ZnCl2 (2.0 M 2-methyltetrahydrofuran solution) (15.0 mL, 30.0 mmol) was added and stirred for 15 minutes. The reaction solution was then returned to room temperature, and 2.27 g (20.0 mmol) of f-2 and 578 mg of Pd(PPh3)4 were added, followed by heating and stirring at 80°C for 18 hours. After completion of the reaction, the mixture was extracted with toluene, and the organic layer was concentrated to dryness. The resulting solid was purified by silica gel column chromatography (toluene:ethyl acetate mixture) to obtain 0.77 g of a transparent solid (f-3) (yield: 12%).

[0224] (2) Synthesis of compound f-4 The following reagents and solvents were placed in a 50 ml recovery flask. Compound f-3: 3.21g (10.0mmol) Iridium chloride hydrate: 0.80g Ethoxyethanol: 12ml Water: 4ml Next, the reaction solution was heated and stirred at 130°C for 5 hours under a nitrogen stream. After the reaction was completed, the reaction solution was filtered, and the obtained solid was washed on the filter with water and methanol. 1.8 g of a yellow solid (f-4) was obtained.

[0225] (3) Compound f-5 synthesis The following reagents and solvents were placed in a 100 ml recovery flask. Compound f-4:1.74(1.00mmol) Silver triflate: 0.514 g (2.00 mmol) Methylene chloride: 30 ml Methanol: 1.3 ml Next, the reaction solution was heated and stirred under a nitrogen stream at room temperature for 6 hours. After the reaction was completed, the solvent was distilled off from the reaction solution at 40° C., yielding 2.24 g of a yellowish brown solid (f-5).

[0226] (4) Synthesis of Example Compound D-1 The following reagents and solvents were placed in a 50 ml recovery flask. Compound f-5: 1.20g Compound f-6: 0.16g (1.00mmol) Ethanol: 50ml Next, the reaction solution was heated and stirred at 90°C for 5 hours under a nitrogen stream. After the reaction was completed, the reaction solution was filtered, and the obtained solid was washed on the filter with water and methanol. The obtained solid was purified by silica gel column chromatography (toluene:ethyl acetate mixture) to obtain 0.32 g (yield: 32%) of a yellow solid (exemplified compound D-1).

[0227] Exemplary Compound D-1 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker). [MALDI-TOF-MS] Measured value: m / z=987 Calculated value: C 59 H 44 IrN3=987

[0228] Examples 2 to 29 (Synthesis of Exemplary Compounds) (Example 15 is a reference example) ] As shown in Tables 4 to 7, the exemplary compounds shown in Examples 2 to 29 were synthesized in the same manner as in Example 1, except that raw material f-1 in Example 1 was replaced with raw material 1, raw material f-2 with raw material 2, and raw material f-6 with raw material 3. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 1 are also shown.

[0229] [Table 4]

[0230] [Table 5]

[0231] [Table 6]

[0232] [Table 7]

[0233] Example 30 (Synthesis of Exemplary Compound D-16) Exemplary compound D-16 was synthesized according to the following scheme: Intermediate f-4 was synthesized in the same manner as in Example 1 using raw material f-3. [ka]

[0234] The following reagents and solvents were placed in a 100 ml recovery flask. Compound f-4: 1.73g (1.00mmol) Compound f-7: 0.40g (4.00mmol) Sodium carbonate: 1.06 g (10.0 mmol) Ethoxyethanol: 33 ml Water: 12ml Next, the reaction solution was heated and stirred at 100°C for 7 hours under a nitrogen stream. After cooling, methanol was added, and the mixture was filtered and washed with methanol to obtain 0.36 g (yield: 39%) of a yellow solid (D-16).

[0235] Mass spectrometry was carried out on Exemplary Compound D-16 in the same manner as in Example 1. [MALDI-TOF-MS] Measured value: m / z=933 Calculated value: C 53 H 46 IrO2N3=933

[0236] [Examples 31 to 35 (Synthesis of Exemplary Compounds)] As shown in Table 8, the exemplary compounds shown in Examples 31 to 35 were synthesized in the same manner as in Example 30, except that raw material f-3 in Example 30 was replaced with raw material 1 and raw material f-7 with raw material 2. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 30 are also shown.

[0237] [Table 8]

[0238] Example 36 (Synthesis of Exemplary Compound J-1) Exemplary compound J-1 was synthesized according to the following scheme. [ka]

[0239] The following reagents and solvents were placed in a 100 ml recovery flask. Compound D-16: 0.93g (1.00mmol) Compound f-3: 0.80g (2.50mmol) Sodium carbonate: 1.06 g (10.0 mmol) Glycerol: 30ml Next, the reaction solution was degassed with nitrogen and then heated and stirred at 180°C for 7 hours. After cooling, methanol was added, and the mixture was filtered and washed with methanol. The resulting solid was purified by silica gel column chromatography (toluene:ethyl acetate mixture) to obtain 0.17 g (yield: 15%) of a yellow solid (exemplified compound J-1).

[0240] Mass spectrometry was carried out on Exemplary Compound J-1 in the same manner as in Example 1. [MALDI-TOF-MS] Measured value: m / z=1153 Calculated value: C 72 H 54 IrN3=1153

[0241] [Examples 37 to 39 (Synthesis of Exemplary Compounds)] As shown in Table 9, the exemplary compounds shown in Examples 37 to 39 were synthesized in the same manner as in Example 36, except that raw material D-16 in Example 36 was replaced with raw material 1 and raw material f-3 with raw material 2. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 36 are also shown.

[0242] [Table 9]

[0243] [Example 40] An organic light-emitting device with a bottom emission structure was fabricated by sequentially forming an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode on a substrate.

[0244] First, an ITO film was formed on a glass substrate and then patterned as desired to form an ITO electrode (anode). At this time, the film thickness of the ITO electrode was set to 100 nm. The substrate on which the ITO electrode was formed was used as the ITO substrate in the following process. Next, a 1.3 × 10 -4 Vacuum deposition was performed by resistance heating in a vacuum chamber at 100 Pa to successively form an organic compound layer and an electrode layer shown in Table 10 on the ITO substrate. At this time, the electrode area of ​​the opposing electrode (metal electrode layer, cathode) was 3 mm 2 It was made to be like this.

[0245] [Table 10]

[0246] The characteristics of the obtained device were measured and evaluated. The efficiency of the light-emitting device was 66 cd / A. Furthermore, at a current density of 50 mA / cm 2 A continuous driving test was performed at 1000 rpm, and the time when the luminance degradation rate reached 5% was measured. In Examples 41 to 47, the time when the luminance degradation rate reached 5% is shown as a ratio when the time in this example is set to 1.0.

[0247] In this example, the measuring device was specifically a microcurrent meter 4140B manufactured by Hewlett-Packard Company to measure the current-voltage characteristics, and a BM7 manufactured by Topcon Corporation to measure the luminance.

[0248] [Examples 41 to 47] An organic light-emitting device was produced in the same manner as in Example 40, except that the materials were appropriately changed to those shown in Table 11. Compound Q-2-1 is the following compound.

[0249] [ka]

[0250] The obtained element was evaluated in the same manner as in Example 40. The time when the luminance degradation rate reached 5% is shown as a ratio when the time in Example 40 is set to 1.0. The measurement results are shown in Table 11.

[0251] [Table 11]

[0252] Table 11 shows that the light-emitting elements according to the present invention have high light-emitting efficiency. Furthermore, the light-emitting elements of Examples 40 to 45 have a hydrocarbon compound as the host material, which has a strong interaction with the compound represented by general formula [1], resulting in high light-emitting efficiency. Furthermore, the stability of the host material is also good, resulting in little luminance degradation. From the above, it can be seen that by using the compound represented by general formula [1] as the light-emitting dopant and selecting a suitable host material, it is possible to provide an element that is highly efficient and has excellent durability.

[0253] [Example 48] An organic light-emitting device was produced in the same manner as in Example 40, except that the compounds and film thicknesses shown in Table 12 were changed.

[0254] [Table 12]

[0255] The obtained device was evaluated in the same manner as in Example 40. The efficiency of the light-emitting device was 66 cd / A. In Examples 49 to 56, the time at which the luminance degradation rate reached 5% is shown as a ratio when the time in this example is set to 1.0.

[0256] [Examples 49 to 56] An organic light-emitting device was produced in the same manner as in Example 48, except for appropriately changing the materials shown in Table 13. The obtained device was evaluated in the same manner as in Example 48. The time when the luminance degradation rate reached 5% is shown as a ratio, assuming that the time when the luminance degradation rate in Example 48 reached 5% was 1.0. The measurement results are shown in Table 13.

[0257] [Table 13]

[0258] Table 13 shows that the light-emitting elements according to the present invention have high light emission efficiency. Furthermore, the light-emitting elements of Examples 48 to 53 have a hydrocarbon compound as the host material, which has a strong interaction with the compound represented by general formula [1], resulting in high light-emitting efficiency. Furthermore, the stability of the host material is also good, resulting in little luminance degradation. From the above, it can be seen that by using the compound represented by general formula [1] as the light-emitting dopant and selecting a suitable host material, it is possible to provide an element that is highly efficient and has excellent durability. [Explanation of symbols]

[0259] 1: interlayer insulating layer, 2: first electrode, 3: insulating layer, 4: organic compound layer, 5: second electrode, 6: protective layer, 7: color filter, 10: subpixel, 11: substrate, 12: insulating layer, 13: gate electrode, 14: gate insulating film, 15: semiconductor layer, 16: drain electrode, 17: source electrode, 18: TFT, 19: insulating film, 20: contact hole, 21: anode, 22: organic compound layer, 23: cathode, 24: first protective layer, 25: second protective layer, 26: organic light-emitting element, 100: display device < / x>

Claims

1. An organic compound represented by the following general formula [1]: 【Chemistry 1】 In formula [1], R 1 ~R 2 are each independently selected from a methyl group and an ethyl group. R 3 are each independently selected from a deuterium atom and a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and 1 represents an integer of 0 to 8. m represents an integer of 1 or more and 3 or less, and n represents an integer of 0 or more and 2 or less, provided that m+n is 3. X represents a bidentate ligand, and the partial structure IrX is either of the structures represented by the following general formula [2] or [3]. 【Chemistry 2】 In formula [2] or [3], R 9 ~R 19 are each independently selected from a hydrogen atom, a deuterium atom, a fluorine atom, a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms, and a substituted or unsubstituted phenyl group. 16 ~R 19 may be bonded to each other to form a ring. Ring A is any of the structures represented by the following general formulas [4] to [7]. 【Transformation 3】 In formulas [4] to [7], R 20 ~R 29 are each independently selected from a hydrogen atom, a deuterium atom, a fluorine atom, a substituted or unsubstituted alkyl group having from 1 to 4 carbon atoms, and a substituted or unsubstituted phenyl group.

2. The organic compound described in Claim 1, characterized in that l is 0.

3. 3. The organic compound according to claim 1, which is represented by the following general formula [10]: 【Chemistry 4】

4. 3. The organic compound according to claim 1, which is represented by the following general formula [11]: 【Transformation 5】

5. The R 20 ~R 29 5. The organic compound according to claim 1, wherein at least one of the groups is a tertiary alkyl group.

6. The organic compound according to claim 5, wherein the tertiary alkyl group is a tertiary butyl group.

7. 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, An organic light-emitting device, wherein at least one of the organic compound layers contains the organic compound according to claim 1 .

8. The organic light-emitting device according to claim 7 , wherein the layer containing the organic compound is a light-emitting layer.

9. The organic light-emitting device according to claim 8 , wherein the light-emitting layer contains a first compound.

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

11. The first compound is SP 3 The organic light-emitting device according to claim 9 or 10, which does not contain carbon.

12. 12. The organic light-emitting element according to claim 9, wherein the first compound has at least one of a chrysene ring, a picene ring, a phenanthrene ring, a triphenylene ring, and a fluorene ring in its skeleton.

13. The organic light-emitting device according to claim 8 , wherein the light-emitting layer contains a third compound.

14. 14. The organic light-emitting device according to claim 13, wherein the third compound is a compound partially having any one of the following structures: 【Transformation 6】 (In the above structure, X' represents either oxygen, sulfur, or a substituted or unsubstituted carbon atom.)

15. A display device comprising a plurality of pixels, at least one of the plurality of pixels comprising the organic light-emitting element according to claim 8 and a transistor connected to the organic light-emitting element.

16. an optical unit having a plurality of lenses, an image pickup element that receives light that has passed through the optical unit, and a display unit that displays an image picked up by the image pickup element; The photoelectric conversion device, wherein the display section comprises the organic light-emitting element according to claim 8 .

17. 15. An electronic device comprising: a display unit having the organic light-emitting element according to claim 8; a housing in which the display unit is provided; and a communication unit provided in the housing and communicating with an external device.

18. 15. A lighting device comprising: a light source having the organic light-emitting element according to claim 8; and a light diffusion section or an optical filter that transmits light emitted by the light source.

19. A moving body comprising: a lamp having the organic light-emitting element according to any one of claims 8 to 14; and a body on which the lamp is provided.

20. An exposure light source for an electrophotographic image forming apparatus, comprising the organic light-emitting element according to claim 8 .

Images