Organic compound and organic light-emitting device

Abstract

To provide an organic compound having high color purity and high luminous efficiency.SOLUTION: An organic compound is represented by formula [1]. (R1 to R14 each represent H, an alkyl group or the like; where, at least one of R1 to R14 is a tertiary alkyl group; m is an integer of 1 or more and 3 or less; m+n is 3; X is 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 progress in organic light-emitting devices has been remarkable, and their characteristics include low driving voltage, a wide range of 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 an organic light-emitting device that uses the following compound a-1 as a light-emitting dopant in a host material that is composed of a non-hydrocarbon compound. Patent Document 2 describes an organic light-emitting device that uses the following compound a-2 as a light-emitting dopant in a host material that is composed of a non-hydrocarbon compound. Patent Document 3 describes an organic light-emitting device that uses the following compound a-3 as a light-emitting dopant in a host material that is composed of a non-hydrocarbon compound. Patent Document 4 describes an organic light-emitting device that uses the following compound a-4 as a light-emitting dopant in a host material that is composed of a non-hydrocarbon compound.

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

[0004] [Patent Document 1] US Patent Application Publication No. 2016 / 0164012 [Patent Document 2] US Patent Application Publication No. 2020 / 0087334 [Patent Document 3] Special Publication No. 2010-523528 [Patent Document 4] US Patent Application Publication No. 2009 / 0123720 Summary of the Invention [Problem to be solved by the invention]

[0005] When compound a-4 is used in the light-emitting layer of an organic light-emitting device, the compound may decompose during vapor deposition of the light-emitting device. Compounds a-1 to a-3 have problems with the luminous efficiency and driving durability characteristics when used in organic light-emitting devices that use a non-hydrocarbon compound as a host. The present invention has been made in view of the above problems, and an object of the present invention is to provide an organic compound having high color purity and excellent luminous efficiency. [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 to R 14 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 aralkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group, provided that R 13 teeth, 4 to 10 carbon atoms It is a tertiary alkyl group. 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 any of the structures represented by the following general formulas [2] and [3].

[0008] [ka] In formulas [2] and [3], R 21 ~R 23 , R 31 ~R 38 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 aralkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 35 ~R 38 may be bonded to each other to form a ring. The organic light-emitting element of the present invention comprises a first electrode, a light-emitting layer, and a second electrode in this order, the light-emitting layer includes a dopant material and a first compound having a minimum excited triplet energy higher than that of the dopant material, The dopant material is a compound represented by the following general formula [1]: The first compound is characterized in that it is a hydrocarbon.

[0009] [ka] In formula [1], R1 to R 14 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 aralkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group, provided that R 13 is a tertiary alkyl group having 4 to 10 carbon atoms, The R1 to R 14 does not contain Si atoms. 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 any of the structures represented by the following general formulas [2] and [3].

[0010] [ka] In formulas [2] and [3], R 21 ~R 23 , R 31 ~R 38 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 aralkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 35 ~R 38 may be bonded to each other to form a ring. [Effects of the Invention]

[0011] The organic compound according to the present invention is a compound that exhibits light emission suitable for green light emission and has high chemical stability. Therefore, by using the organic compound according to the present invention as a constituent material of an organic light-emitting device, an organic light-emitting device having good light-emitting properties and excellent durability can be obtained.

[0012] Furthermore, the organic light-emitting device according to the present invention emits green light with good color purity, has high luminous efficiency, and is excellent in driving durability. [Brief explanation of the drawings]

[0013] [Figure 1] 1A is a schematic cross-sectional view showing an example of a pixel of a display device according to one embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view showing an example of a display device using an organic light-emitting element according to one embodiment of the present invention. [Figure 2] 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Figure 3] (a) A schematic diagram showing an example of an imaging device according to an embodiment of the present invention. (b) A schematic diagram showing an example of an electronic device according to an embodiment of the present invention. [Figure 4] (a) A schematic diagram showing an example of a display device according to an embodiment of the present invention. (b) A schematic diagram showing an example of a foldable display device. [Figure 5] (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 6] (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 7] (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 an image forming apparatus according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0014] (1) The organic compound and dopant material of the present invention The organic compound and dopant material of the present invention are compounds represented by the following general formula [1]. The organic compound of the present invention is a compound in which at least one of R1 to R 14 is a tertiary alkyl group, and the dopant material of the present invention is a compound in which R1 to R 14 does not contain a Si atom. In this specification, a coordination bond is indicated by a straight line or an arrow.

[0015]

Chemical formula

[0016] <R1 to R 14 > In formula [1], R1 to R 14are 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 aralkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 14 At least one of R to R is a tertiary alkyl group. 14 does not contain Si atoms.

[0017] Examples of halogen atoms include, but are not limited to, fluorine, chlorine, bromine, and iodine.

[0018] Examples of alkyl groups include, but are not limited to, methyl, ethyl, normal propyl, isopropyl, normal butyl, tertiary butyl, secondary butyl, octyl, cyclohexyl, tertiary pentyl, 3-methylpentan-3-yl, 1-adamantyl, and 2-adamantyl groups. Among these, examples of tertiary alkyl groups include tertiary butyl, tertiary pentyl, 3-methylpentan-3-yl, and 1-adamantyl groups, with tertiary butyl being preferred. As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferred.

[0019] Examples of the aralkyl group include, but are not limited to, a benzyl group.

[0020] Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, 2-ethyl-octyloxy, and benzyloxy groups. Preferred alkoxy groups have 1 to 10 carbon atoms.

[0021] Examples of the aryloxy group include, but are not limited to, a phenoxy group and a naphthoxy group.

[0022] Examples of heteroaryloxy groups include, but are not limited to, furanyloxy groups and thienyloxy groups.

[0023] 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.

[0024] Examples of heterocyclic groups include, but are not limited to, pyridyl, pyrimidyl, pyrazyl, triazyl, benzofuranyl, benzothiophenyl, dibenzofuranyl, dibenzothiophenyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazolyl, acridinyl, and phenanthrolyl groups. Preferred heterocyclic groups are those having 3 to 27 carbon atoms.

[0025] Examples of substituents that may be further substituted by the alkyl group, aralkyl group, alkoxy group, aryloxy group, heteroaryloxy 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, heterocyclic groups such as pyridyl group and pyrrolyl 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, cyano group, and thiol group.

[0026] In the organic compound of the present invention, R to R 14Preferably, R1 to R2 do not contain Si atoms. 14 At least one of these is preferably a tertiary alkyl group.

[0027] In the organic compound and the dopant material of the present invention, R to R 14 At least one of R is preferably a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group, 11 ~R 14 At least one of R is preferably a tertiary alkyl group. 13 is preferably a tertiary butyl group.

[0028] <m、n> In formula [1], 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.

[0029] <x> In formula [1], X represents a bidentate ligand, and the partial structure IrX is any of the structures represented by the following general formulae [2] and [3].

[0030] [ka]

[0031] [R 21 ~R 23 , R 31 ~R 38 ] In formulas [2] and [3], R 21 ~R 23 , R 31 ~R 38 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 aralkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group.

[0032] R 21 ~R 23 , R 31 ~R 38 Specific examples of the halogen atom, alkyl group, aralkyl group, alkoxy group, aryloxy group, heteroaryloxy group, aryl group, and heterocyclic group represented by the formula (I) include R1 to R2. 14 Examples of the substituents that may be further introduced by the alkyl group, aralkyl group, alkoxy group, aryl group, heteroaryloxy group, aryl group, heteroaryloxy group, aryl group, heterocyclic group, heterocyclic group, heteroaryloxy group, heteroaryl group, heterocyclic group, heteroaryl ... 14 Examples of the above-described examples include, but are not limited to, those described above.

[0033] Also, adjacent R 35 ~R 38 may be bonded to each other to form a ring. 35 ~R 38 are bonded to each other to form a ring, R 35 and R 36 , R 36 and R 37 , R 37 and R 38 and a ring formed by bonding R 35 ~R 38 is bonded to a benzene ring to form a condensed ring.

[0034] The compound represented by the general formula [1] has the following characteristics. (1-1) The ligand has a triphenylene ring, and thus the compound has an emission wavelength of 520 nm to 550 nm, which is necessary for a green-emitting dopant. (1-2) The ligand has a triphenylene ring, which provides high hole transport properties. These features will be explained below.

[0035] (1-1) The ligand has a triphenylene ring, and thus the compound has an emission wavelength of 520 nm to 550 nm, which is necessary for a green-emitting dopant.

[0036] The iridium complex represented by general formula [1] has high oscillator strength and high quantum yield due to the coordination of iridium with a triphenylene ring, which has three fused benzene rings. Furthermore, as shown in Table 1, Compound 1, whose ligand has a triphenylene ring, has a longer emission wavelength than Comparative Compound 1, and was found to have an emission wavelength of 520 nm to 550 nm, which is necessary for a green-emitting dopant. Compound 1 is Exemplary Compound B-1, which will be described later. The green emission line is 546 nm, but since green phosphorescent materials have a broadened peak on the longer wavelength side of the first emission peak, a first emission peak shorter than 546 nm may result in higher purity. Therefore, an emission wavelength range of 520 nm to 550 nm is preferred for a green-emitting dopant. The emission wavelengths below were determined based on the peak values ​​of the emission spectrum in a dilute toluene solution.

[0037] [Table 1]

[0038] (1-2) The ligand has a triphenylene ring, which provides high hole transport properties.

[0039] The iridium complexes represented by the general formula [1] have high hole transport properties due to the triphenylene rings in the ligands. This is thought to be due to the structure in which the triphenylene rings of the ligands easily overlap, facilitating hole hopping between the ligands.

[0040] Furthermore, the compound represented by the general formula [1] preferably has the following characteristics. (1-3)R1 to R 14 When at least one of the groups is a tertiary alkyl group, the sublimation property is improved. (1-4)R 11 ~R 14 It is more preferable that at least one of the groups is a tertiary alkyl group. (1-5)R1 to R 14 At least one of the groups is preferably a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group. This is explained below.

[0041] (1-3)R1 to R 14 When at least one of the groups is a tertiary alkyl group, the sublimation property is improved.

[0042] The iridium complex represented by the general formula [1] has the above characteristics (1-1) and (1-2) due to the presence of a triphenylene ring, but the presence of a condensed polycyclic ring results in a large molecular weight of the complex, which may result in poor sublimability. Specifically, when the temperature during sublimation purification is high, or when the complex is partially decomposed after sublimation purification, the R1 to R 14 At least one of the groups is preferably a tertiary alkyl group. This suppresses molecular stacking between complexes, thereby lowering the sublimation temperature. Tertiary alkyl groups are sterically bulkier than hydrogen atoms or primary or secondary alkyl groups, and therefore have a greater effect of excluding complexes from one another and suppressing molecular stacking. Furthermore, the use of a tertiary alkyl group can reduce radical cleavage of hydrogen at the benzyl position due to temperature when subjected to high temperature loads.

[0043] Table 2 shows the bond dissociation energies of carbon-hydrogen bonds described in ACC. Chem. Res. 36, 255-263, (2003).

[0044] [Table 2]

[0045] 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 of the π electrons with the adjacent benzene ring. For this reason, the carbon-hydrogen bond at the benzylic position is a weak bond. Therefore, if the molecular structure does not contain a structure such as a benzyl group, the carbon-hydrogen bond is less likely to be broken, which is preferable.

[0046] Table 3 shows the sublimation temperature during the sublimation purification of each material. The degree of vacuum during the sublimation purification was 1×10 -3 From 1×10 -2 Compound 3 is the exemplified compound A-1 described later, and comparative compound 2 is compound a-2. 14 It can be seen that the sublimation temperature is lower when at least one of the groups is a tertiary alkyl group.

[0047] [Table 3]

[0048] (1-4)R 11 ~R 14 It is more preferable that at least one of the groups is a tertiary alkyl group.

[0049] The tertiary alkyl group mentioned in (1-3) is a group with high electron donating properties. In the iridium complex represented by the general formula [1], the LUMO is distributed on the pyridine ring side that bonds to the triphenylene ring of the ligand. Therefore, R 11 ~R 14 When at least one of R is a tertiary alkyl group, the emission wavelength becomes shorter, resulting in a greener emission wavelength with better color purity. 13 The figure shows the difference in emission wavelength depending on whether R is a tertiary butyl group or not. 13 The tertiary butyl group shortens the emission wavelength by about 5 nm, resulting in a greener emission wavelength with better color purity.

[0050] [Table 4]

[0051] Furthermore, as mentioned in (1-2), the iridium complex represented by the general formula [1] has a triphenylene ring in the ligand, which gives it a high hole transport property. This is thought to be due to the structure in which the triphenylene rings of the ligands tend to overlap, making it easy for holes to hop between the ligands. Therefore, in order to prevent the overlap between the triphenylene rings from decreasing, R 11 ~R 14 It is more preferable that at least one of the groups is a tertiary alkyl group.

[0052] (1-5)R1 to R 14 At least one of the groups is preferably a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group.

[0053] As mentioned in (1-3), R1 to R 14 When at least one of R1 to R2 is a tertiary alkyl group, the sublimation property is improved. 14 At least one of the groups is preferably a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group, which has low planarity and strong bond energy.

[0054] The iridium complexes represented by the general formula [1] may have poor sublimation properties due to their large molecular weight and strong ligand stacking. Hydrogen atoms, deuterium atoms, halogen atoms, cyano groups, alkyl groups, and alkoxy groups are preferred because they do not increase the sublimation temperature as much as highly planar groups such as phenyl groups and fused polycyclic groups.

[0055] Furthermore, hydrogen atoms, deuterium atoms, halogen atoms, cyano groups, alkyl groups, and alkoxy groups have higher bond energy with the carbon of the triphenylene ring than carbon-silicon bonds such as amino groups and silyl groups, and are therefore less likely to decompose during sublimation or vapor deposition at high sublimation temperatures, making them preferable. Comparative compound 2 shown in Table 3 has a trimethylsilyl group with low bond dissociation energy, and decomposed during sublimation purification.

[0056] <Example> Specific examples of the organic compound and dopant material of the present invention are shown below, but of course, are not limited to these. (A-1 to 20, B-3, 6, 10, C-1 to 20, D-6, 8, 9, 19, E-1 to 5, F-5 are examples) .

[0057] [ka]

[0058] [ka]

[0059] [ka]

[0060] [ka]

[0061] [ka]

[0062] The exemplary compounds belonging to group A and exemplary compound B-3 are compounds represented by general formula [1] that have two triphenylene ring-containing ligands. The presence of two highly planar triphenylene rings results in high hole mobility and a high degree of orientation of the compound, thereby improving the light extraction efficiency of the light-emitting device.

[0063] The exemplary compounds belonging to Group B other than exemplary compound B-3 are compounds represented by general formula [1], which have two triphenylene ring-containing ligands, and the triphenylene ring-containing ligands have a tertiary alkyl group. By reducing intermolecular stacking, sublimation properties are improved and concentration quenching in the light-emitting layer can be suppressed.

[0064] The exemplary compounds belonging to Group C and exemplary compound D-9 are compounds represented by general formula [1], each of which has one triphenylene ring-containing ligand. The highly planar triphenylene ring provides high hole mobility. Furthermore, compared with the compounds belonging to Group A and exemplary compound B-3, the molecular weights of these compounds are lower and the sublimation temperatures are lower.

[0065] The example compounds belonging to Group D other than Example Compound D-9 are compounds represented by the general formula [1], which have one ligand having a triphenylene ring, and the ligand having the triphenylene ring has a tertiary alkyl group. Compared to the compounds of Group C and Example Compound D-9, the intermolecular stacking is reduced, which improves sublimation and suppresses concentration quenching in the light-emitting layer.

[0066] The exemplary compounds belonging to Group E are compounds represented by the general formula [1] that have three triphenylene ring-containing ligands. The presence of three highly planar triphenylene rings results in extremely high hole mobility.

[0067] The exemplary compounds belonging to Group F are compounds represented by the general formula [1], which have three triphenylene ring-containing ligands, and the triphenylene ring-containing ligands have a tertiary alkyl group. Compared to the compounds belonging to Group E, these compounds have reduced intermolecular stacking, which improves sublimation and suppresses concentration quenching in the light-emitting layer.

[0068] Among these, the following compounds are preferred.

[0069] [ka]

[0070] (2) Characteristics of organic light-emitting devices The organic light-emitting element of the present invention includes a first electrode, an emitting layer, and a second electrode in this order. The emitting layer includes a dopant material and a first compound having a higher minimum excited triplet energy than the dopant material, and has the following characteristics:

[0071] (2-1) The dopant material of the light-emitting layer is a compound represented by the general formula [1], and the first compound is a hydrocarbon, so that the interaction between the dopant material and the first compound is strong and energy transfer is easy. (2-2) The effect of (2-1) above promotes the transport hopping of holes between the dopant material and the host material, thereby improving the hole transportability in the light-emitting layer. This is explained below.

[0072] (2-1) The dopant material of the light-emitting layer is a compound represented by the general formula [1], and the first compound is a hydrocarbon, so that the interaction between the dopant material and the first compound is strong and energy transfer is easy.

[0073] The compound represented by general formula [1] has a fused polycyclic ring composed of a hydrocarbon with four fused benzene rings as a ligand, and has a triphenylene ring with extremely high planarity. On the other hand, the first compound (host material) uses a hydrocarbon, preferably a fused polycyclic compound with high planarity. By having a similar hydrocarbon structure, preferably a highly planar structure, in both the host and the ligand of the dopant material (guest material), ππ interactions are easily formed, facilitating energy transfer from the first compound to the dopant material.

[0074] 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. That is, the intermolecular distance between the host material and the guest material is shortened by ππ interaction, resulting in efficient energy transfer from the host material to the guest material.

[0075] The above-mentioned effects allow triplet excitons generated in the host material to be quickly consumed for light emission, resulting in an organic light-emitting device with high light-emitting efficiency. 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 device.

[0076] On the other hand, compounds other than hydrocarbons, such as compounds having an amino group containing highly polar atoms such as nitrogen, oxygen, and sulfur, and compounds having heterocyclic compounds such as a carbazolyl group and a dibenzothiophenyl group, have high polarity. Therefore, if the host material is a compound other than hydrocarbons, the interaction with the highly planar triphenylene ring becomes weaker, and the above-mentioned effect of promoting energy transfer is inhibited.

[0077] The concentration of the dopant material is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.1% by mass or more and 10% by mass or less, based on the total mass of the light-emitting layer.

[0078] (2-2) The effect of (2-1) above is to promote the transport hopping of holes between the dopant material and the host material, thereby improving the hole transportability in the light-emitting layer.

[0079] The compound represented by general formula [1] has a low HOMO level (close to the vacuum level) due to the triphenylene ring in the ligand, and therefore tends to have 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 dopant material and the host material. In this case, it is preferable to use similar skeletons for the host material and the dopant material. In this case, the fused rings of the host material and the dopant material overlap closely, allowing for efficient hole transfer between the dopant material 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.

[0080] Furthermore, the organic light-emitting device of this embodiment preferably has the following features. (2-3) The light-emitting layer further contains an assist material, whose LUMO level is lower (farther from the vacuum level) than that of the first compound, 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.

[0081] (2-3) The light-emitting layer further contains an assist material, whose LUMO level is lower (farther from the vacuum level) than that of the first compound, thereby confining both electron and hole carriers in the light-emitting layer and providing a highly efficient device.

[0082] The iridium complex represented by general formula [1] promotes hole injection into the light-emitting layer, so it is preferable to improve efficiency by injecting electrons and holes into the light-emitting layer in a balanced manner, and it is preferable to promote electron injection into the light-emitting layer. Because the host material is a hydrocarbon, it has a wide band gap. Therefore, the host material has a high LUMO level (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 include an assist material. Furthermore, the LUMO level of the assist material is preferably lower than the LUMO level of the first compound (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.

[0083] (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.

[0084] As described above, the element of this embodiment exhibits the effect of promoting hole injection in the light-emitting layer by the dopant material and confining holes in the light-emitting layer by the hole trap, thereby reducing hole injection from the light-emitting layer into the hole blocking layer and electron transport layer and reducing hole-induced deterioration of the hole blocking layer and electron transport layer.

[0085] 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.

[0086] (3) First compound (host material) The first compound as the host material is a hydrocarbon. The first compound must have a T1 (lowest triplet excitation energy) higher than that of the iridium complex represented by general formula [1], which is the dopant material. Specifically, since the dopant material of this embodiment emits light in the 520 nm to 550 nm region, T1 is preferably 2.4 eV or higher. Furthermore, as described above, a fused polycyclic compound having three or more rings is preferred to enhance the interaction with the triphenylene ring of the ligand of the dopant material.

[0087] Furthermore, the first compound preferably has the following characteristics: (3-1) The skeleton has at least one of a triphenylene ring, a phenanthrene ring, a chrysene ring, and a fluoranthene ring. (3-2)SP 3 It has no carbon.

[0088] The above will be explained below. (3-1) The skeleton has at least one of a triphenylene ring, a phenanthrene ring, a chrysene ring, and a fluoranthene ring.

[0089] The dopant material of this embodiment has a triphenylene skeleton in the ligand. The triphenylene skeleton has a highly planar structure. In order for the dopant material and the first compound to interact as described above in (2-1) and (2-2), it is preferable that the first compound 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 triphenylene moiety of the dopant material and the planar moiety of the first compound are more likely to approach each other. This is expected to shorten the intermolecular distance between the dopant material and the first compound. The above effects lead to the effect of increasing the efficiency of energy transfer described in (2-1).

[0090] Here, examples of highly planar structures include hydrocarbon structures containing condensed polycyclic rings, such as triphenylene ring, phenanthrene ring, chrysene ring, and fluoranthene ring.

[0091] (3-2)SP 3 It has no carbon.

[0092] As described in the above explanation (3-1), the dopant material of this embodiment is a compound characterized by improving the interaction and luminescence properties by improving the distance from the first compound. The first compound may further include SP 3 By using a material that does not contain carbon, the distance to the dopant material can be shortened.

[0093] <Example> Specific examples of the first compound are shown below, but the first compound is not limited to these.

[0094] [ka]

[0095] [ka]

[0096] The above-mentioned exemplary compounds have at least one of a triphenylene ring, a phenanthrene ring, a chrysene ring, and a fluoranthene ring in the skeleton, and are SP 3 These compounds are compounds that do not contain carbon. Therefore, these compounds can be closer to the dopant material of this embodiment, and therefore have a strong interaction, making them host materials that transfer energy to the dopant material well. Among these, compounds that have a triphenylene ring in the skeleton are particularly preferred because they have high planarity.

[0097] When the assist material is not included, the concentration of the first compound is preferably from 50% to 99.9% by mass, and more preferably from 75% to 99% by mass, based on the entire light-emitting layer. When the assist material is included, the concentration of the first compound is preferably from 40% to 90% by mass, and more preferably from 60% to 80% by mass, based on the entire light-emitting layer.

[0098] (4) Assist materials The light-emitting layer preferably further contains an assist material, the LUMO level of which is preferably lower (farther from the vacuum level) than the LUMO level of the first compound.

[0099] The iridium complex represented by general formula [1] promotes hole injection into the light-emitting layer, and thus preferably enhances efficiency by injecting electrons and holes into the light-emitting layer in a balanced manner, and more preferably promotes electron injection into the light-emitting layer. Furthermore, since the first compound is a hydrocarbon and lacks an electron-withdrawing group, its LUMO level is high, potentially resulting in poor electron injection from the electron-transporting layer. However, the inclusion of an assist material can improve electron injection. The assist material preferably has a LUMO level lower than that of the first compound. 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.

[0100] The assist material is preferably a compound partially having any one of the following structures:

[0101] [ka]

[0102] (In the above structure, X' represents an oxygen atom, a sulfur atom, or a substituted or unsubstituted carbon atom.)

[0103] The above structure is effective because it has electron-withdrawing properties and can reduce the LUMO level of the assist material. In addition, an assist material containing the above structure as a partial structure is considered to be unlikely to form an exciplex with the dopant material of this embodiment because it has moderately high electron-withdrawing properties and a moderate size, and is therefore preferable. An assist material that is considered likely to form an exciplex with the dopant material of this embodiment includes a compound containing a triazine ring as a partial structure.

[0104] 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.

[0105] Examples of halogen atoms include, but are not limited to, fluorine, chlorine, bromine, and iodine.

[0106] 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.

[0107] Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, 2-ethyl-octyloxy, and benzyloxy groups.

[0108] Examples of the aryloxy group include, but are not limited to, a phenoxy group and a naphthoxy group.

[0109] Examples of heteroaryloxy groups include, but are not limited to, furanyloxy groups and thienyloxy groups.

[0110] 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.

[0111] 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.

[0112] Examples of the silyl group include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0113] 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.

[0114] Examples of substituents that the alkyl group, alkoxy group, aryloxy group, heteroaryloxy group, aryl group, heterocyclic group, amino group, and silyl group may further have include, but are not limited to, deuterium, alkyl groups such as methyl group, ethyl group, normal propyl group, isopropyl group, normal butyl group, and 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.

[0115] <Example> Specific examples of the assist material are shown below, but the material is not limited to these.

[0116] [ka]

[0117] [ka]

[0118] [ka]

[0119] The concentration of the assist material is preferably 10% by mass or more and 60% by mass or less, and more preferably 20% by mass or more and 40% by mass or less, based on the total mass of the light-emitting layer.

[0120] (5) Details of organic light-emitting devices Next, the organic light-emitting device of this embodiment will be described.

[0121] The organic light-emitting element of this embodiment has at least a first electrode, a second electrode, and an organic compound layer disposed between these electrodes. One of the first electrode and the second electrode is an anode and the other is a cathode. 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 an emitting layer. Here, when the organic compound layer is a laminate consisting of multiple layers, the organic compound layer may have, in addition to the 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 emitting layer may be a single layer or a laminate consisting of multiple layers.

[0122] In the organic light-emitting device of this embodiment, at least one of the organic compound layers contains the organic compound of this embodiment. Specifically, the organic compound of this embodiment is contained in any of the above-mentioned light-emitting layer, hole injection layer, hole transport layer, electron blocking layer, hole / exciton blocking layer, electron transport layer, electron injection layer, etc. The organic compound of this embodiment is preferably contained in the light-emitting layer.

[0123] 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.

[0124] 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 mainly responsible for emitting light. The assist material is the compound with a mass ratio smaller than that of the host among the compounds constituting the light-emitting layer, and assists the light emission of the guest. The assist material is also called a second host. The host material can also be called the first compound, and the assist material can also be called the second compound.

[0125] When the organic compound according to this embodiment is used as a guest in the light-emitting layer, the concentration of the guest is preferably 0.01% by mass or more and 20% by mass or less, and more preferably 0.1% by mass or more and 10% by mass or less, based on the total mass of the light-emitting layer.

[0126] The present inventors have conducted various studies and found that when the organic compound according to this embodiment is used as a host or guest in the light-emitting layer, particularly as a guest in the light-emitting layer, a device exhibiting high efficiency and high luminance light output and extremely high durability can be obtained. This light-emitting layer may be a single layer or multiple layers, and it is also possible to mix the green light emitted by this embodiment with a light-emitting material having another light-emitting color by adding the other light-emitting material. "Multiple layers" refers to a state in which the light-emitting layer and another light-emitting layer are stacked. In this case, the light-emitting color of the organic light-emitting element is not limited to green. More specifically, it may be white or a neutral color. In the case of white, the other light-emitting layer emits a color other than green, i.e., blue or red.

[0127] The film is formed by vapor deposition or coating, the details of which will be explained in detail in the examples below.

[0128] 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, it may be used as a constituent material of an electron transport layer, an electron injection layer, a hole transport layer, a hole injection layer, a hole blocking layer, etc. In this case, the emission color of the organic light-emitting device is not limited to green. More specifically, it may emit white light or a neutral color.

[0129] In addition to the organic compound according to this embodiment, conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host compounds, light-emitting compounds, electron-injecting or electron-transporting compounds, etc. may also be used together as needed. Examples of these compounds are listed below.

[0130] 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.

[0131] [ka]

[0132] 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, HT3, HT4, HT5, 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.

[0133] Examples of light-emitting materials that are primarily involved in light-emitting function 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 listed below, but the present invention is not limited to these.

[0134] [ka]

[0135] [ka]

[0136] When the luminescent material is a hydrocarbon compound, it is preferable because it can reduce the decrease in luminous efficiency due to exciplex formation and the decrease in color purity due to changes in the emission spectrum of the luminescent material due to exciplex formation. Hydrocarbon compounds are compounds composed only of carbon and hydrogen, and among the above-mentioned exemplified compounds, BD7, BD8, GD5 to GD9, and RD1 are examples.

[0137] When the light-emitting material is a fused polycyclic ring containing a five-membered ring, it is preferable because it has a high ionization potential, is resistant to oxidation, and results in a device with a long and durable life. Among the above-mentioned exemplary compounds, BD7, BD8, GD5 to GD9, and RD1 are preferred.

[0138] Examples of the light-emitting layer host or light-emitting assist material contained in the light-emitting layer include aromatic hydrocarbon compounds or derivatives thereof, as well as carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, and organic beryllium complexes. Specific examples of compounds used as the light-emitting layer host or light-emitting assist material contained in the light-emitting layer are shown below, but the present invention is not limited to these.

[0139] [ka]

[0140] When the host material is a hydrocarbon compound, the compound of this embodiment is preferable because it easily traps electrons and holes, resulting in a significant effect of improving efficiency. The hydrocarbon compound is a compound composed only of carbon and hydrogen, and among the above-mentioned exemplary compounds, EM1 to EM26 are examples.

[0141] 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.

[0142] [ka]

[0143] 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. They can also be used in combination with the above electron transport materials.

[0144] <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.

[0145] [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.

[0146] [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.

[0147] 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.

[0148] 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.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] [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.

[0153] 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.

[0154] 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.).

[0155] 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.

[0156] 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.

[0157] 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.

[0158] [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.

[0159] [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.

[0160] [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.

[0161] 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.

[0162] [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.

[0163] 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.

[0164] [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.

[0165] [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.

[0166] 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.

[0167] [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.

[0168] 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.

[0169] 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.

[0170] <Uses of the organic light-emitting device according to this embodiment> 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.

[0171] 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.

[0172] 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.

[0173] Next, a display device according to this embodiment will be described with reference to the drawings. Fig. 1 is a cross-sectional view showing an example of a display device having an organic light-emitting element and a transistor connected to the organic light-emitting element. The transistor is an example of an active element. The transistor may be a thin-film transistor (TFT).

[0174] FIG. 1(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 the light emitted from the sub-pixels. 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 edges 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.

[0175] 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).

[0176] 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 contacts the organic compound layer 4 and becomes a light-emitting region.

[0177] 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 .

[0178] The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0179] 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.

[0180] 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.

[0181] The display device 100 in FIG. 1(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 comprises 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.

[0182] 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. 1(b). In other words, it is sufficient that either the anode 21 or the cathode 23 is electrically connected to either the source electrode 17 or the drain electrode 16 of the TFT 18. TFT stands for thin film transistor.

[0183] 1(b), the organic compound layer 22 is illustrated as a single layer, but may be a multi-layer organic compound layer 22. A first protective layer 24 and a second protective layer 25 are provided on the cathode 23 to reduce deterioration of the organic light-emitting element 26.

[0184] Although the display device 100 in FIG. 1(b) uses transistors as switching elements, other switching elements may be used instead.

[0185] The transistors used in the display device 100 of Fig. 1(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.

[0186] The transistors included in the display device 100 of Fig. 1(b) may be formed within a substrate such as a Si substrate. Here, "formed within a substrate" means that the substrate itself, such as a Si substrate, is processed to form the transistors. In other words, having a transistor within a substrate can be seen as the substrate and the transistor being integrally formed.

[0187] 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.

[0188] 2 is a schematic diagram illustrating an example of a display device according to this embodiment. The display device 1000 may include a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. The touch panel 1003 and the display panel 1005 are connected by flexible printed circuits FPCs 1002 and 1004. Transistors are printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position even if the display device is a portable device.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] 3A is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 may include a display device according to this embodiment. In this case, the display device may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the speed at which the subject is moving, the possibility that the subject will be blocked by an obstruction, and the like.

[0193] 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.

[0194] 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.

[0195] FIG. 3(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 operations such as unlocking. 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.

[0196] FIG. 4 is a schematic diagram illustrating an example of a display device according to this embodiment. FIG. 4(a) illustrates a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The display unit 1302 may 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. 4(a). The lower side of the frame 1301 may also serve as the base. The frame 1301 and the display unit 1302 may be curved. The radius of curvature may be 5000 mm or more and 6000 mm or less.

[0197] FIG. 4(b) is a schematic diagram illustrating another example of a display device according to this embodiment. The display device 1310 in FIG. 4(b) is configured to be bendable, and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 may include 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.

[0198] FIG. 5(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 device. If necessary, a cover may be provided on the outermost surface.

[0199] 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.

[0200] 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.

[0201] 5(b) is a schematic diagram of an automobile, which is an example of a moving body according to this embodiment. The automobile has tail lamps, which are an example of lighting fixtures. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking or the like is performed.

[0202] 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.

[0203] 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.

[0204] 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.

[0205] An application example of the display device of each of the above-described embodiments will be described with reference to Fig. 6. The display device can be applied to a system that can be attached as a wearable device, such as smart glasses, an HMD, or a smart contact lens. An image capturing and displaying device used in such an application example includes an image capturing device capable of photoelectrically converting visible light and a displaying device capable of emitting visible light.

[0206] Fig. 6(a) is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention. Using Fig. 6(a), glasses 1600 (smart glasses) according to one application example will be described. An imaging device 1602 such as a CMOS sensor or 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.

[0207] 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.

[0208] FIG. 6(b) is a schematic diagram showing another example of a wearable device according to an embodiment of the present invention. Using FIG. 6(b), glasses 1610 (smart glasses) according to one application example will be described. The glasses 1610 have a control device 1612, which is equipped with an imaging device corresponding to the imaging device 1602 in FIG. 6(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.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] 7(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.

[0215] 7(b) and 7(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, which represents 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. 7(b) shows a configuration in which the light-emitting units 36 are arranged along the long axis direction of the photoconductor 27. FIG. 7(c) shows a configuration different from FIG. 7(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. 7(c) can also be described as a grid arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0216] 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]

[0217] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0218] Example 1 (Synthesis of Exemplary Compound C-1) (Reference example) ] Exemplary compound C-1 was synthesized according to the following scheme. [ka]

[0219] (1) Synthesis of compound f-3 The following reagents and solvents were placed in a 200 ml recovery flask. Compound f-1: 7.08g (20.0mmol) Compound f-2: 2.27g (20.0mmol) Sodium carbonate: 5.3 g (50.0 mmol) Pd(PPh3)4: 578 mg Toluene: 35 ml Water: 35ml Ethanol: 10ml The reaction solution was then heated and stirred at 60°C for 5 hours under a nitrogen stream. After the reaction was completed, 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 3.5 g of a transparent solid (f-3) (yield: 57%).

[0220] (2) Synthesis of compound f-5 The following reagents and solvents were placed in a 50 ml recovery flask. Compound f-4: 3.10g (20.0mmol) Iridium chloride hydrate: 1.60g Ethoxyethanol: 18ml Water: 6ml 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. 3.4 g of a yellow solid (f-5) was obtained (yield: 63%).

[0221] (3) Synthesis of compound f-6 The following reagents and solvents were placed in a 100 ml recovery flask. Compound f-5: 1.07g (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 at room temperature for 7 hours under a nitrogen stream. After the reaction was completed, the solvent was distilled off from the reaction solution at 40° C., and 1.56 g of a yellowish brown solid (f-6) was obtained.

[0222] (4) Synthesis of exemplary compound C-1 The following reagents and solvents were placed in a 50 ml recovery flask. Compound f-6: 1.50g Compound f-3: 3.05g (1.00mmol) Ethanol: 50ml Next, the reaction solution was heated and stirred at 90°C for 6 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 0.15 g (yield: 19%) of a yellow solid (exemplified compound C-1).

[0223] Exemplary Compound C-1 was subjected to mass spectrometry using MALDI-TOF-MS (Autoflex LRF, manufactured by Bruker). [MALDI-TOF-MS] Measured value: m / z=805 Calculated value: C 45 H 30 IrN3=805

[0224] Examples 2 to 14 (Synthesis of Exemplary Compounds) (Examples 2 to 5, 8, and 9 are reference examples) ] As shown in Tables 5 to 6, the exemplary compounds shown in Examples 2 to 14 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-4 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.

[0225] [Table 5]

[0226] [Table 6]

[0227] Example 15 (Synthesis of Exemplary Compound A-16) (Reference example) ] Exemplary compound A-16 was synthesized according to the following scheme. [ka]

[0228] (1) Synthesis of compound f-7 The following reagents and solvents were placed in a 50 ml recovery flask. Compound f-3: 6.10g (20.0mmol) Iridium chloride hydrate: 1.60g Ethoxyethanol: 36 ml Water: 12ml 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. 4.3 g of a yellow solid (f-7) was obtained (yield: 51%).

[0229] (2) Synthesis of Example Compound A-16 The following reagents and solvents were placed in a 100 ml recovery flask. Compound f-7: 1.67g (1.00mmol) Compound f-8: 0.40g (4.00mmol) Sodium carbonate: 1.06 g (10.0 mmol) Ethoxyethanol: 30ml Water: 12ml Next, the reaction solution was heated and stirred at 100°C for 6 hours under a nitrogen stream. After cooling, methanol was added, and the mixture was filtered and washed with methanol to obtain 0.42 g of a yellow solid (A-16) (yield: 46%).

[0230] Mass spectrometry was carried out on Exemplary Compound A-16 in the same manner as in Example 1. [MALDI-TOF-MS] Measured value: m / z=903 Calculated value: C 51 H 38 IrO2N3=900

[0231] Examples 16 to 19 (Synthesis of Exemplary Compounds) (Example 16 is a reference example) ] As shown in Table 7, the exemplary compounds shown in Examples 16 to 19 were synthesized in the same manner as in Example 15, except that raw material f-3 in Example 15 was replaced with raw material 1 and raw material f-8 with raw material 2. The actual measured values ​​(m / z) of the mass spectrometry results measured in the same manner as in Example 15 are also shown.

[0232] [Table 7]

[0233] Example 20 (Synthesis of Exemplary Compound E-1) (Reference example) ] Exemplary compound E-1 was synthesized according to the following scheme. [ka]

[0234] (1) Synthesis of Example Compound E-1 The following reagents and solvents were placed in a 100 ml recovery flask. Compound A-16: 0.90g (1.00mmol) Compound f-3: 0.64g (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 10 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 0.18 g (yield: 16%) of a yellow solid (exemplified compound E-1).

[0235] Mass spectrometry was carried out on Exemplary Compound E-1 in the same manner as in Example 1. [MALDI-TOF-MS] Measured value: m / z=1105 Calculated value: C 69 H 42 IrN3=1105

[0236] Example 21 (Reference example) ] 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.

[0237] 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 1.33 × 10 -4 Vacuum deposition was performed by resistance heating in a vacuum chamber at 100 Pa to successively form the organic compound layer and electrode layer shown in Table 8 on the ITO substrate. At this time, the electrode area of ​​the opposing electrode (metal electrode layer, cathode) was 3 mm 2 The host material (first compound) has a minimum excited triplet energy greater than that of the dopant material.

[0238] [Table 8]

[0239] The characteristics of the obtained device were measured and evaluated. As shown in Table 9, the maximum emission wavelength of the light-emitting device was 534 nm, and the efficiency was 58 cd / A. Furthermore, at a current density of 50 mA / cm 2 A continuous driving test was carried out at 1000 Hz, and the time when the brightness degradation rate reached 5% was measured.

[0240] 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.

[0241] Examples 22 to 29 (Examples 21, 22, 25, and 26 are reference examples) ] In Examples 22 to 29, organic light-emitting devices were fabricated in the same manner as in Example 21, except that the materials for the light-emitting layer were appropriately changed as shown in Table 9. The host material (first compound) had a higher minimum excited triplet energy than the dopant material. The resulting devices were evaluated in the same manner as in Example 21. The time when the luminance degradation rate reached 5% is expressed as a ratio, with the time in Example 21 taken as 1.0. The measurement results are shown in Table 9.

[0242] [Table 9]

[0243] In Table 9, the dopant materials of Examples 23, 24, 27-29 are R 13 The dopant materials of Examples 21, 22, 25, and 26 are compounds having a tertiary alkyl group at R. Therefore, the emission wavelength is 529 nm to 530 nm, which is the optimum emission wavelength for green. 13 This compound does not have a tertiary alkyl group, and therefore emits light with a longer wavelength than the dopant materials of Examples 23, 24, and 27-29.

[0244] [Example 30] An organic light-emitting device was produced in the same manner as in Example 21, except that the compounds and film thicknesses were changed to those shown in Table 10. The host material (first compound) has a higher minimum excited triplet energy than the dopant material.

[0245] [Table 10]

[0246] The characteristics of the obtained element were measured and evaluated in the same manner as in Example 21. As shown in Table 11, the maximum emission wavelength of the light-emitting element was 530 nm, and the efficiency was 58 cd / A.

[0247] [Examples 31 to 36, Comparative Examples 1 to 5] In Examples 31 to 36 and Comparative Examples 1 to 5, organic light-emitting devices were fabricated in the same manner as in Example 30, except that the materials for the light-emitting layer were appropriately changed as shown in Table 11. The host material (first compound) has a higher minimum excited triplet energy than the dopant material. Compounds Q-2-1 to Q-2-3 and S-4-1 are shown below.

[0248] [ka]

[0249] The obtained element was evaluated in the same manner as in Example 30. 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 30 reached 5% was 1.0. The measurement results are shown in Table 11.

[0250] [Table 11]

[0251] The LUMO levels of the host material and the assist material used in the examples are shown in Table 12. The LUMO levels were calculated by determining the ionization potential (IP) using an atmospheric photoelectron spectrometer AC-3 manufactured by Riken Keiki Co., Ltd. and subtracting the optical band gap (BG) determined using an ultraviolet-visible spectrophotometer manufactured by JASCO Corporation.

[0252] [Table 12]

[0253] As can be seen from Table 11, the host materials in Comparative Examples 1 to 5 contain nitrogen or sulfur, and thus have lower efficiency or a shorter lifespan than the devices in Examples 30 to 36, which use hydrocarbons as the host material. Furthermore, the devices in Examples 30 to 34 contain an assist material with a lower LUMO level than the host material. Therefore, the efficiency is higher than that of Example 35, which does not contain an assist material, and Example 36, which contains an assist material with a higher LUMO level than the host material. Therefore, by selecting a hydrocarbon as the host material and an assist material with a lower LUMO level than the host material, it is possible to provide devices with high efficiency and long lifespan. [Explanation of symbols]

[0254] 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 14 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 aralkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group, with the proviso that R 13 is a tertiary alkyl group having from 4 to 10 carbon atoms. 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 any of the structures represented by the following general formulas [2] and [3]. 【Chemistry 2】 In formulas [2] and [3], R 21 ~R 23 , R 31 ~R 38 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 aralkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 35 ~R 38 may be bonded to each other to form a ring.

2. The R 1 ~R 14 The organic compound according to claim 1, characterized in that it does not contain a Si atom.

3. The R 1 3. The organic compound according to claim 1, wherein at least one of R 12 to R 14 is a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group.

4. 4. The organic compound according to claim 1, wherein the tertiary alkyl group is a tertiary butyl group.

5. 5. The organic compound according to claim 4, which is any one of the following compounds: 【Transformation 3】

6. a first electrode, a light-emitting layer, and a second electrode in this order; the light-emitting layer includes a dopant material and a first compound having a minimum excited triplet energy higher than that of the dopant material, The dopant material is a compound represented by the following general formula [1]: The organic light-emitting device, wherein the first compound is a hydrocarbon. 【Chemistry 4】 In formula [1], R 1 ~R 14 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 aralkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group, provided that R 13 is a tertiary alkyl group having from 4 to 10 carbon atoms, and R 1 ~R 14 does not contain Si atoms. 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 any of the structures represented by the following general formulas [2] and [3]. 【Transformation 5】 In formulas [2] and [3], R 21 ~R 23 , R 31 ~R 38 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 aralkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted heteroaryloxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 35 ~R 38 may be bonded to each other to form a ring.

7. The R 1 7. The organic light-emitting element according to claim 6, wherein at least one of R12 to R14 is a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted alkoxy group.

8. 8. The organic light-emitting device according to claim 6, wherein the tertiary alkyl group is a tertiary butyl group.

9. 9. The organic light-emitting device according to claim 8, wherein the dopant material is any one of the following compounds: 【Transformation 6】

10. 10. The organic light-emitting element according to claim 6, wherein the first compound has at least one of a triphenylene ring, a phenanthrene ring, a chrysene ring, and a fluoranthene ring in its skeleton.

11. The organic light-emitting element according to any one of claims 6 to 10, wherein the light-emitting layer further comprises an assist material, and the LUMO level of the assist material is lower (farther from the vacuum level) than the LUMO level of the first compound.

12. The organic light-emitting device according to claim 11, wherein the assist material is a compound partially having any one of the following structures: 【Transformation 7】 (X' represents an oxygen atom, a sulfur atom, or a substituted or unsubstituted carbon atom.)

13. 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 6 and a transistor connected to the organic light-emitting element.

14. 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 6 .

15. 13. An electronic device comprising: a display unit having the organic light-emitting element according to claim 6; a housing in which the display unit is provided; and a communication unit provided in the housing and communicating with an external device.

16. 13. A lighting device comprising: a light source having the organic light-emitting element according to claim 6; and a light diffusion section or an optical filter that transmits light emitted from the light source.

17. A moving body comprising: a lamp having the organic light-emitting element according to claim 6; and a vehicle on which the lamp is provided.

18. An exposure light source for an electrophotographic image forming apparatus, comprising the organic light-emitting element according to claim 6 .

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