Organic light-emitting device

Abstract

To provide an organic light-emitting device that is highly efficient and excellent in drive durability characteristics.SOLUTION: An organic light-emitting device has a substrate, a first electrode, a luminous layer, and a second electrode. The luminous layer includes a first organic compound, a second organic compound, and a third organic compound. In the first to third organic compounds, a freely rotatable single bond is a carbon-carbon bond. At least one carbon in the freely rotatable carbon-carbon bond in the second organic compound is sp2 carbon. When the energy level of the HOMO of the first organic compound is defined as HOMO1, the energy level of the LUMO of the second organic compound is defined as LUMO2, and the energy levels of the HOMO and the LUMO of the third organic compound are defined as HOMO3 and LUMO3, the following [I] and [II] are satisfied. [I] |LUMO2|>|LUMO3|; [II] |HOMO3|>|HOMO1|.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an organic light-emitting element, various devices and apparatuses having the organic light-emitting element, and an organic compound used in the organic light-emitting element. [Background technology]

[0002] An organic light-emitting element (sometimes called an "organic electroluminescence element" or an "organic EL element") is an electronic element having a pair of electrodes and an organic compound layer disposed between the electrodes. By injecting electrons and holes from the pair of electrodes, excitons of a light-emitting organic compound in the organic compound layer are generated, and when the excitons return to the ground state, the organic light-emitting element emits light. Recent progress in organic light-emitting devices has been remarkable, including low driving voltage, diverse emission wavelengths, high-speed response, and the possibility of making the light-emitting devices thinner and lighter. Meanwhile, organic light emitting devices can emit light of various colors, but improving the durability of blue light emitting devices, which have the highest energy in the visible region, is a particular issue. One of the methods for improving the durability of an element is improvement of the light-emitting layer structure. Patent Document 1 reports an example of a green organic light-emitting element having a ternary light-emitting layer in which a third organic compound is used for a pyrene-based host and a fluoranthene dopant having a tert-butyl group. Patent Document 2 reports an example of a blue organic light-emitting element having a ternary light-emitting layer in which a third organic compound is used for a carbazole-based host and a dopant having a diarylamino group. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-71194 A [Patent Document 2] JP 2010-245061 A Summary of the Invention [Problem to be solved by the invention]

[0004] To provide displays with even higher reliability, organic light-emitting elements with longer life are required, and improving the durability of high-energy blue organic light-emitting elements in particular is a challenge. Patent Document 1 discloses an example of a light-emitting device that uses three types of organic compounds to adjust the HOMO-LUMO levels of the light-emitting layer and improve durability. 3 Carbon-sp 3 Carbon-containing dopants have been used, and further improvement in durability performance is desired. Patent Document 2 discloses an example of a blue light-emitting device that uses three types of organic compounds to adjust the HOMO-LUMO levels of the light-emitting layer and improve durability. However, the dopant used has a carbon-nitrogen single bond with low bond energy, and further improvement in durability is desired. The present invention has been made in view of the above problems, and an object of the present invention is to provide an organic light-emitting device having excellent durability characteristics. [Means for solving the problem]

[0005] The present invention provides an organic light-emitting device having a first electrode, a light-emitting layer, and a second electrode, the light-emitting layer contains a first organic compound, a second organic compound, and a third organic compound; the first organic compound, the second organic compound, and the third organic compound each have a freely rotatable single bond that is a carbon-carbon bond; At least one carbon atom of a freely rotatable carbon-carbon bond contained in the second organic compound is sp 2 Carbon, When the energy level of the HOMO of the first organic compound is HOMO1, the energy level of the LUMO of the second organic compound is LUMO2, and the energy levels of the HOMO and LUMO of the third organic compound are HOMO3 and LUMO3, the compound satisfies the following [I] and [II]. |LUMO2|>|LUMO3| [I] |HOMO3|>|HOMO1| [II] Effect of the Invention

[0006] According to the present invention, an organic light-emitting element having excellent driving durability can be provided, and excellent equipment and devices can be provided by using the organic light-emitting element. [Brief description of the drawings]

[0007] [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. [Diagram 2] FIG. 1 is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention. [Diagram 3] 1A is a schematic diagram illustrating an example of an imaging device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram illustrating an example of an electronic device according to an embodiment of the present invention. [Figure 4] 1A is a schematic diagram illustrating an example of a display device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram illustrating an example of a foldable display device. [Diagram 5] 1A is a schematic diagram showing an example of an illumination device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram showing an example of an automobile having a vehicle lamp according to an embodiment of the present invention. [Figure 6] 1A is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention, and FIG. 1B is a schematic diagram showing an example of a wearable device according to an embodiment of the present invention, the wearable device having an imaging device. [Figure 7] 1A is a schematic diagram of an image forming apparatus according to one embodiment of the present invention, and FIG. 1B and FIG. 1C are schematic diagrams showing an embodiment in which a plurality of light-emitting units of an exposure light source are arranged on a long substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The present invention is an invention for providing an organic light-emitting element with a long life. In order to achieve a long life of an organic light-emitting element, it is necessary to prevent the deterioration of the organic materials in the element, particularly the organic materials used in the light-emitting layer. In general, in order to extend the life of an organic light-emitting element, it is effective to expand the recombination region and prevent the deterioration caused by the concentration of exciton generation. When the exciton generation is concentrated, energy transfer occurs from another excited molecule to an excited molecule, resulting in a transition to a higher energy state. In the high energy state, if a situation occurs in which the bond energy of the single bond site in the molecular structure is exceeded, the bond is cleaved and decomposition products are generated, causing brightness deterioration. In order to avoid this, it is effective to disperse the exciton generation.

[0009] There are several methods for dispersing the exciton generation region. In the present invention, it is considered that a method in which charge injection into the light-emitting layer is good and the exciton generation region is dispersed is effective by adding two types of organic compounds, a first organic compound with hole trapping properties and a second organic compound with electron trapping properties, to the host compound. In other words, the following relationships [I] and [II] are satisfied. The third organic compound is a host. |LUMO2|>|LUMO3| [I] |HOMO3|>|HOMO1| [II] HOMO1: The energy level of the HOMO of the first organic compound HOMO3: The energy level of the HOMO of the third organic compound LUMO2: LUMO energy level of the second organic compound LUMO3: The energy level of the LUMO of the third organic compound

[0010] Incidentally, HOMO means the highest occupied molecular orbital, and LUMO means the lowest unoccupied molecular orbital. The energy level of HOMO is sometimes called "HOMO" or "HOMO level", and the energy level of LUMO is sometimes called "LUMO" or "LUMO level".

[0011] The features of the light-emitting layer configuration in the present invention will be described below. In the present specification, specific examples of the substituents are as follows, unless otherwise specified.

[0012] The alkyl group may be an alkyl group having from 1 to 20 carbon atoms. Examples of the alkyl group include, but are not limited to, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a tert-butyl group, a sec-butyl group, an octyl group, a cyclohexyl group, a 1-adamantyl group, and a 2-adamantyl group.

[0013] The alkoxy group may be an alkoxy group having from 1 to 10 carbon atoms. Examples include, but are not limited to, a methoxy group, an ethoxy group, a propoxy group, a 2-ethyl-octyloxy group, and a benzyloxy group.

[0014] Examples of the silyl group include, but are not limited to, a trimethylsilyl group and a triphenylsilyl group.

[0015] The aryl group may be an aryl group having a carbon number of 6 to 20. Examples of the aryl group include, but are not limited to, a phenyl group, a naphthyl group, an indenyl group, a biphenyl group, a terphenyl group, a fluorenyl group, a phenanthryl group, a fluoranthenyl group, and a triphenylenyl group.

[0016] The heteroaryl group may be a heteroaryl group having from 3 to 20 carbon atoms. Examples of the heteroaryl group include, but are not limited to, a pyridyl group, a pyrimidyl group, a pyrazyl group, a triazolyl group, an oxazolyl group, an oxadiazolyl group, a thiazolyl group, a thiadiazolyl group, a carbazolyl group, an acridinyl group, a phenanthrolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group.

[0017] 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, and a carbazolyl group.

[0018] Examples of the aryloxy group and heteroaryloxy group include, but are not limited to, a phenoxy group and a thienyloxy group.

[0019] Examples of substituents that may be further substituted by the alkyl group, alkoxy group, silyl group, aryl group, heteroaryl group, amino group, aryloxy group, and heteroaryloxy group include, but are not limited to, a deuterium atom; halogen atoms such as fluorine, chlorine, bromine, and iodine; alkyl groups such as a methyl group, an ethyl group, a normal propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group; alkoxy groups such as a methoxy group, an ethoxy group, and a propoxy group; amino groups such as a dimethylamino group, a diethylamino group, a dibenzylamino group, a diphenylamino group, and a ditolylamino group; aryloxy groups such as a phenoxy group; aromatic hydrocarbon groups such as a phenyl group and a biphenyl group; heteroaryl groups such as a pyridyl group and a pyrrolyl group; a cyano group, a hydroxy group, and a thiol group.

[0020] [1] The freely rotatable single bond of the compound constituting the light-emitting layer is a carbon-carbon bond. One of the features of the organic light-emitting device of the present invention is that holes in the light-emitting layer are mainly trapped on the first organic compound, and electrons in the light-emitting layer are mainly trapped on the second organic compound, which allows charges to be confined within the light-emitting layer and disperses recombination regions, improving durability.

[0021] In other words, this means that the first organic compound and the second organic compound are subjected to a load in a radical state or an excited state. Therefore, the first organic compound and the second organic compound need to have a skeleton that is resistant to decomposition even in a high-energy excited state, and furthermore, since charge recombination and excitation also occur in the third organic compound, which is the host, it is desirable for the skeleton to be similarly resistant to decomposition, which is a feature of the present invention. Specifically, it is important that all of the freely rotatable single bonds are carbon-carbon bonds for the skeleton to be resistant to decomposition. Furthermore, at least one of the freely rotatable single bonds is a sp 2 It is preferable that the cyclic group is composed of carbon. Furthermore, all of the freely rotatable single bonds are sp 2 Carbon-sp 2 It is preferably a carbon bond. 2 , sp 3 What is sp 2 hybrid orbital, sp 3 This means hybrid orbitals.

[0022] Table 1 shows examples of bond energies of freely rotatable single bonds. As shown in Table 1, when a carbon-nitrogen bond or the like is provided as a bond between condensed polycyclic skeletons, the bond is likely to break in a higher excited energy state generated by a certain concentration of exciton generation. Therefore, in the present invention, the freely rotatable single bond in each of the first organic compound, the second organic compound, and the third organic compound is a carbon-carbon bond.

[0023] [Table 1]

[0024] Table 2 shows a comparison of durability characteristics of organic light-emitting devices using the light-emitting layer configuration and materials described in Prior Art Document 2 and the light-emitting layer configuration and materials of the present invention. "Present Invention 1" and "Comparative Example 1" to "Comparative Example 3" in Table 2 correspond to Example 1 and Comparative Examples 1 to 3 in the Examples described later. The units of LUMO level and HOMO level are [eV]. The fabrication method, layer configuration, evaluation, and measurement method of HOMO level and LUMO level of the organic light-emitting device are as described in the Examples described later.

[0025] [Table 2]

[0026] As shown in Table 2, Comparative Examples 1 to 3 in which the light-emitting layer materials had C-N bonds in the freely rotatable single bonds had durability ratios of 1.0 or less, whereas the light-emitting layer material of Invention 1 in which all the freely rotatable single bonds were carbon-carbon bonds had a durability ratio of 1.3. Therefore, it is preferable for the constituent material of the light-emitting layer that all the freely rotatable single bonds are carbon-carbon bonds with high bond energy.

[0027] [2] At least one of the freely rotatable carbon-carbon bonds of the second organic compound is sp 2 It is carbon. In the present invention, the second organic compound has a deep LUMO level (far from the vacuum level) and is an electron trapping compound. The first organic compound has a shallow HOMO level and is a hole trapping compound. In addition, in all of the first to third organic compounds, all of the freely rotatable single bonds are carbon-carbon bonds, so that the HOMO-LUMO of both the first organic compound and the second organic compound is likely to be deep. In other words, the difference in the LUMO level (electron trapping performance) between the third organic compound and the second organic compound is greater than the difference in the HOMO level (hole trapping performance) between the third organic compound and the first organic compound. Therefore, among the organic compounds constituting the light-emitting layer, the second organic compound has the highest probability of trapping and exciting charges, and is prone to decomposition due to charges and excitons. Therefore, among the first to third organic compounds, it is preferable that the bond stability of the second organic compound is particularly high.

[0028] As shown in Table 1, the stability of the bond energy is 2 Carbon-nitrogen bond, sp 3 Carbon-sp 3 carbon bond, sp 3 Carbon-sp 2 carbon bond, sp 2 Carbon-sp 2 From this result, it can be seen that the carbon-carbon bond is 3 Carbon-sp 3 Carbon bonds have low bond energy and are prone to decomposition or reaction in an excited state, so that the luminance of the organic light-emitting device tends to deteriorate during operation. In other words, the durability of the organic light-emitting device tends to deteriorate. 2 Carbon-sp 3 Carbon bond or sp 2 Carbon-sp 2 The carbon bond is sp 3 Carbon-sp 3 The bond energy is higher than that of a carbon bond, and decomposition or reaction is suppressed in an excited state, thereby improving the durability of the organic light-emitting device.

[0029] Table 3 compares an organic light-emitting device made of the light-emitting layer material described in Prior Art Document 1 with an organic light-emitting device made of the light-emitting layer material of the present invention. "Invention 2" to "Invention 4" and "Comparative Example 4" in Table 3 correspond to Example 2 to Example 4 and Comparative Example 4 in the Examples described later. The units of the LUMO level and HOMO level are [eV]. The fabrication method, layer structure, and evaluation of the organic light-emitting device are as described in the Examples described later.

[0030] [Table 3]

[0031] As shown in Table 3, the second organic compound has a sp 3 Carbon-sp 3 In comparison with Comparative Example 4 having a carbon bond, sp 3 Carbon-sp 3The present invention 4, which does not have a carbon bond, shows better durability. 2 Carbon-sp 3 The sp 2 Carbon-sp 2 The present invention 3, which is composed of only carbon bonds, shows better durability. Furthermore, in all of the first to third organic compounds, the freely rotatable single bonds are sp 2 Carbon-sp 2 In the present invention 2, which is a carbon bond, better durability properties are shown. Therefore, the second organic compound according to the present invention is sp 3 Carbon-sp 2 Carbon bonds and sp 2 Carbon-sp 2 Consists of only carbon bonds, i.e., at least one is sp 2 By using an organic compound having a carbon-carbon bond, the durability of the organic light-emitting device is improved.

[0032] In the present invention, it is more preferable that the present invention further has the following characteristics. [3] The second organic compound has a fluoranthene skeleton. As mentioned above, the second organic compound is characterized by having a deep LUMO level (far from the vacuum level) and electron trapping ability relative to the host (third organic compound), but it is preferable that the fluoranthene skeleton is used as the skeleton with a deep LUMO level. This is because the fluoranthene skeleton has an electron-deficient five-membered ring and is composed of only stable hydrocarbons, and further, by containing two or more five-membered rings, the LUMO level becomes deeper and the electron trapping ability is improved, which is preferable.

[0033] In addition, the electron blocking layer material is generally a freely rotatable sp 2Since it has a carbon-nitrogen bond and is electron-rich in the neutral state, it is easy to receive electrons (reduction) or decompose in the excited state. Therefore, in a device configuration having an electron blocking layer or a hole blocking layer, the durability of the device is improved by biasing the recombination region toward the hole blocking layer / light emitting layer interface side rather than the electron blocking layer / light emitting layer interface. For this reason, it is preferable that the second organic compound has a deep LUMO relative to the host compound and has electron trapping properties. In addition, it is more preferable to use a first organic compound in which the freely rotatable single bond is a carbon-carbon bond in the electron blocking layer, since decomposition is suppressed from the viewpoint of molecular structure stability.

[0034] [4] The first organic compound is stable against oxidation. As described above, the first organic compound is highly likely to exist in a radical cation state. Therefore, it is preferable that the first organic compound is particularly stable in the radical cation state. Table 4 shows the results of evaluating the oxidation stability of two types of organic compounds by performing 10 consecutive sweep evaluations of one-electron oxidation using cyclic volmetry (CV) measurement. The CV measurement was performed in a dichloromethane solution of 0.1 M tetrabutylammonium perchlorate, and the reference electrode was Ag / Ag. + The measurement was performed using a Pt counter electrode and a glassy carbon working electrode. The sweep speed was 0.1 V / s. The measurement device used was an electrochemical analyzer, Model 660C, manufactured by ALS. The element durability ratio was evaluated using an element configuration similar to that of the present invention 2 (Example 2) in Table 3.

[0035] [Table 4]

[0036] As shown in Table 4, it was found that organic compound 1, which gave a reversible oxidation wave, had an element durability ratio that was 1.4 times higher than organic compound 2, which gave an irreversible oxidation wave. This indicates that organic compound 1, which has a molecular structure with high oxidation stability, can exist stably without decomposing or reacting even after one-electron oxidation.

[0037] [5] The freely rotatable single bonds of the first to third organic compounds are all sp 2 Carbon-sp 2 It is a carbon bond. As described in [2] above, the freely rotatable single bond of the second organic compound is preferably one having a higher bond energy, and the sp 2 Carbon-sp 2 Carbon bonds are preferred. However, charge recombination and excitation also occur in the third organic compound and the first organic compound, which are the hosts, to a greater or lesser extent. Therefore, the freely rotatable single bonds of the first organic compound and the third organic compound constituting the light-emitting layer are preferably sp 2 Carbon-sp 2 More preferably, it consists of only carbon bonds.

[0038] [6] The freely rotatable single bond of the first organic compound is sp 2 Carbon-sp 2 In the case of carbon bonds, the organic compound is preferably represented by the general formula [1]. More preferably, the organic compound is represented by the following general formula [1] and is composed only of hydrocarbons.

[0039] [ka]

[0040] In the above general formula [1], R1 to R 26 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 may form a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 11 ~R 15 , R20 ~R 24 may form a ring with adjacent substituents.

[0041] The organic compound represented by the above general formula [1] has a hole trapping property, and therefore has a high excitation probability and a high bond energy. In addition, it has high oxidation stability, and is therefore preferable as the first organic compound.

[0042] In the present invention, the first organic compound is characterized in that it has a shallow HOMO level (close to the vacuum level) relative to the third organic compound serving as a host, and has a hole trapping property. However, in general, the freely rotatable single bond is sp 2 Carbon-sp 2 It is very difficult to create a compound that is composed of only carbon bonds and has a shallow HOMO level. As a result of intensive research, the present inventors have found that the HOMO level is shallower by having the molecular structure of the general formula [1]. Specifically, by adding a biphenyl unit to a pyrene skeleton, which is also a useful basic skeleton for a third organic compound or a second organic compound, the electron density of the molecule is improved by stacking more effectively in a thin film, and the effect of shallowing the HOMO level is expressed. Furthermore, the HOMO level is shallower when two or more biphenyl units are added.

[0043] Table 5 shows the calculated and measured HOMO levels, and the difference (ΔHOMO) between the presence and absence of biphenyl units and the number of substitutions in organic compounds related to the first organic compound. The measured HOMO levels are the ionization potential values ​​measured using an AC-3 made by Riken Keiki after preparing a 50 nm film. It was found that the calculated HOMO values ​​of organic compounds 1 to 5 in Table 5 are all the same, but the measured HOMO values ​​become shallower as the number of biphenyl units increases. In other words, the effect of shallowing the HOMO by adding biphenyl units cannot be predicted by calculation, but was discovered by the present inventors.

[0044] [Table 5]

[0045] Therefore, the freely rotatable single bond of the first organic compound is sp 2 Carbon-sp 2 When the compound is composed only of carbon bonds, the hole trapping performance can be improved by using an organic compound having a shallower HOMO, as represented by the general formula [1], and the durability of the organic light-emitting device can be further improved.

[0046] The first organic compound is preferably an organic compound represented by the following general formula [1-1] or [1-2]. Note that the general formula [1-1] is the same as the general formula [1] except that R 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 At least one of the groups forms a ring.

[0047] [ka]

[0048] In the above general formula [1-1], R1 to R 26 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 At least one pair of R forms a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 11 ~R 15 , R 20 ~R 24 may form a ring with adjacent substituents. In the above general formula [1-2], R1 to R 38are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 18 ~R 19 , R 25 ~R 26 , R 28 may form a ring with adjacent substituents.

[0049] More preferably, the organic compound is represented by the following general formula [1-3]. [ka]

[0050] In the above general formula [1-3], R1 to R 38 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 19 and R 20 , R 24 and R 25 At least one pair of R forms a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 20 ~R 24 may form a ring with adjacent substituents.

[0051] The organic compounds represented by the above general formula [1-1] or [1-2], and further [1-3], are preferred for the following three reasons. (i) Since the glass transition temperature (Tg) is increased, the thermal stability is high and the driving durability is improved. (ii) The HOMO becomes shallower, which enhances hole trapping properties and improves drive durability. (iii) Since the band gap is narrowed, the injection barrier is small and the driving voltage is reduced. Each item will be explained below.

[0052] (i) Since the glass transition temperature (Tg) is increased, the thermal stability is high and the driving durability is improved. High thermal stability, for example, high glass transition temperature (Tg), is preferable when used in an organic light-emitting device. This is because a high Tg makes it difficult for grain boundaries, trap levels, and quenchers to be generated due to microcrystallization even during device operation, and good carrier transport properties and highly efficient light-emitting properties can be maintained. As a result, an organic light-emitting device with excellent durability and efficiency can be provided.

[0053] Table 6 shows the results of the evaluation of the Tg of organic compounds Z-3, Z-4, Z-18 to Z-20 described later by differential scanning calorimetry (DSC). It can be said that the higher the glass transition temperature, the higher the amorphousness and the better the thermal stability. The Tg is preferably 120°C or higher, more preferably 130°C or higher, and even more preferably 140°C or higher. In addition, when performing DSC measurements, about 2 mg of sample was sealed in an aluminum pan, and the sample was rapidly cooled from a high temperature exceeding the melting point to make the sample amorphous, and then the glass transition temperature was measured by increasing the temperature at a rate of 20°C / min. The measurement device used was a "DSC 204 F1" ​​manufactured by NETZSCH.

[0054] [Table 6]

[0055] It was found that compared with Z-4 or Z-18 in which a biphenyl derivative (triphenylene or spirofluorene) is substituted on only one side of pyrene, Z-3 or Z-19 in which a biphenyl derivative (biphenyl and triphenylene or spirofluorene) is substituted on both sides of pyrene has a Tg improved by about 20° C. Therefore, the first organic compound is preferably an organic compound represented by the following general formula [1-1].

[0056] In addition, it was found that Z-18 or Z-19, which is substituted with spirofluorene as a substituent group for pyrene, has a Tg improved by about 20°C or more compared to Z-3 or Z-4, which is substituted with triphenylene. Therefore, as the first organic compound, an organic compound represented by general formula [1-2] is preferable. In addition, an organic compound represented by general formula [1-3], which is substituted with spirofluorene and a biphenyl derivative, is more preferable.

[0057] (ii) Since the HOMO is shallow, the hole trapping ability is high and the driving durability is improved. As described above, the shallower the HOMO (the closer it is to the vacuum level), the more the hole trapping ability is improved, and the more the driving durability characteristics are improved. As shown in Table 6, it was found that Z-18 or Z-19, which is substituted with spirofluorene as a substituent for pyrene, has a shallower HOMO than Z-3 or Z-4, which is substituted with triphenylene. Therefore, as the first organic compound, an organic compound represented by the general formula [1-2] is preferable in terms of its high hole trapping property.

[0058] (iii) Since the band gap is narrowed, the injection barrier is small and the driving voltage is reduced. In organic light-emitting devices, when charges are injected from the charge injection layer or charge blocking layer to the light-emitting layer, the smaller the band gap (S1 energy), the smaller the injection barrier and the lower the driving voltage. In addition, the smaller the injection barrier, the better the charge accumulation at the interface between the light-emitting layer and the adjacent layer, and the better the driving durability. As shown in Table 6, it was found that Z-3 or Z-19, in which a biphenyl derivative is substituted on both sides of pyrene, has a smaller S1 than Z-4 or Z-18, in which a biphenyl derivative is substituted on only one side of pyrene. Therefore, as the first organic compound, an organic compound represented by the general formula [1-1] is preferable in terms of reducing the voltage. In addition, by changing the biphenyl group substituted on one side of pyrene in Z-19 to a terphenyl group as in Z-20, S1 is further reduced, which is more preferable in terms of reducing the voltage.

[0059] [7] The material of the hole blocking layer has a condensed ring skeleton made of a hydrocarbon. As mentioned in [3] above, electron blocking materials generally have freely rotatable sp 2 Since it has a carbon-nitrogen bond and is electron-rich in a neutral state, it is easy to receive electrons (reduction) or to decompose in an excited state. Therefore, when an electron blocking layer or a hole blocking layer is provided in contact with the light-emitting layer, it is preferable that the recombination region is biased toward the interface between the hole blocking layer and the light-emitting layer, and it is also preferable that the material of the hole blocking layer has a stable molecular structure. For example, a skeleton such as a nitrogen-containing heterocycle is electron-deficient in a neutral state, so it is easy to decompose when electrons are extracted. In other words, it is easy to decompose due to holes leaking from the light-emitting layer. Therefore, a condensed ring skeleton made of a hydrocarbon that is stable even when electrons are extracted (oxidized) is preferable because it has good durability.

[0060] In addition, since the hole blocking layer is also an electron transport layer, it is preferable that the electron mobility is high. Therefore, among the fused ring skeletons made of hydrocarbons, it is preferable that the fused ring structure has four or more rings. This is because the electron mobility is improved by increasing the planarity.

[0061] Specific examples of the first to third organic compounds will be given below. <Third organic compound> In the present invention, the third organic compound used as the host of the light-emitting layer has all freely rotatable single bonds being carbon-carbon bonds, and preferably has a structure such as sp 2 Carbon-sp 2 There is no particular limitation other than that the compound is composed of carbon bonds. Preferably, the compound has any of an anthracene skeleton, a phenanthroline skeleton, a pyrene skeleton, a chrysene skeleton, a benzophenanthrene skeleton, a triphenylene skeleton, a fluoranthene skeleton, a benzochrysene skeleton, and a benzofluorane skeleton. Preferably, the compound is an organic compound represented by the following general formula [2].

[0062] [ka]

[0063] In the above general formula [2], R1 to R8 and R 27 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. n is a natural number selected from 1 to 3.

[0064] Specific examples of the third organic compound are given below, but the invention is not limited thereto.

[0065] [ka]

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] <First organic compound> The first organic compound has all freely rotatable single bonds being carbon-carbon bonds, and preferably has sp 2 Carbon-sp 2 There is no particular limitation other than that it is a carbon bond. Preferred examples include an organic compound represented by the above-mentioned general formula [1], an organic compound represented by the above-mentioned general formula [2] given as a preferred example of the third organic compound, and an organic compound having a partial skeleton represented by the following general formulas [3-1] to [3-4].

[0075] [ka]

[0076] In the above general formulas [3-1] to [3-4], the cyclic units A to C are aromatic hydrocarbon groups or heterocyclic groups, and may be condensed. Q1 to Q3 are each independently selected from a direct bond, CR1R2, NR3, an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. The substituents R1 to R3 are each independently selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group. R3 may form a ring with the adjacent cyclic units A to C.

[0077] Specific examples of the preferred first organic compound represented by the general formula [1] are shown below, but the invention is not limited to these.

[0078] [ka]

[0079] [ka]

[0080] Specific examples of the preferred first organic compound represented by the general formula [2] are shown below, but the invention is not limited to these.

[0081] [ka]

[0082] Specific examples of the partial skeletons represented by the general formulae [3-1] to [3-4] are shown below, but the invention is not limited thereto.

[0083] [ka]

[0084] [ka]

[0085] Specific examples of the first organic compound having a partial skeleton represented by the general formulas [3-1] to [3-4] are shown below, but the invention is not limited thereto.

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] [ka]

[0091] [ka]

[0092] [ka]

[0093] [ka]

[0094] In addition, the first organic compound can also be used as the third organic compound. In the present invention, when selecting the first organic compound and the third organic compound, it is sufficient that the relationship between the LUMO and the HOMO satisfies the above-mentioned relationships [I] and [II].

[0095] <Second organic compound> The second organic compound has a structure in which the freely rotatable single bonds are carbon-carbon bonds, and at least one of the carbon-carbon bonds is sp 2 There is no particular limitation other than being composed of carbon, but it is preferable that the second organic compound has a fluoranthene skeleton. Furthermore, it is preferable that the number of five-membered rings is 2 or more. Specific examples of the fused ring skeleton that the second organic compound preferably has are shown below, but are not limited thereto.

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] Preferable specific examples of the second organic compound are shown below, but the present invention is not limited thereto.

[0101] [ka]

[0102] [ka]

[0103] [ka]

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109] [ka]

[0110] [ka]

[0111] The organic light-emitting element of the present embodiment has a pair of electrodes and an organic compound layer disposed between the pair of electrodes. Here, the organic compound layer has at least a light-emitting layer, and when the organic compound layer is a laminate consisting of a plurality of layers, it may have a hole injection layer, a hole transport layer, an electron blocking layer, a hole-exciton blocking layer, an electron transport layer, an electron injection layer, etc. in addition to the light-emitting layer. The light-emitting layer may be a single layer or a laminate consisting of a plurality of layers.

[0112] In the organic light-emitting device of the present embodiment, at least one of the organic compound layers contains the first organic compound, the second organic compound, and the third organic compound. The layer containing the first to third organic compounds is preferably an emission layer. In the case of an emission layer, the third organic compound is a host, the second organic compound is a guest, and the first organic compound is an assist.

[0113] 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 smaller mass ratio than the host among the compounds constituting the light-emitting layer, and is the compound that is mainly responsible for emitting light. The assist is the compound with a smaller mass ratio than the host among the compounds constituting the light-emitting layer, but equal to or greater than the guest. In other words, the mass ratio is host > assist ≧ guest.

[0114] The light-emitting layer according to this embodiment is composed of at least three kinds. The concentration of the host is preferably 50% by mass or more and 99% by mass or less, more preferably 50% by mass or more and 98% by mass or less, based on the entire light-emitting layer. The concentration of the guest is preferably 0.1% by mass or more and 20% by mass or less, based on the entire light-emitting layer, and from the viewpoint of preventing concentration quenching, is preferably 1% by mass or more and 10% by mass or less. Furthermore, the concentration of the assist is preferably more than 0.5% by mass or more and 49.09% by mass or less, more preferably 2% by mass or more and 49.09% by mass or less, and more preferably 5% by mass or more and 49.09% by mass or less, based on the entire light-emitting layer.

[0115] The guest may be uniformly contained throughout the layer in which the host is the matrix, or may be contained with a concentration gradient.The guest may also be contained partially in a specific region within the layer, so that the light-emitting layer has a region containing only the host and no guest.

[0116] The light-emitting layer may be a single layer or multiple layers, and it is also possible to mix colors by including a light-emitting material having another light-emitting color. Multiple layers means a state in which two or more light-emitting layers are laminated. In this case, the light-emitting color of the organic light-emitting element is not particularly limited. More specifically, it may be white or an intermediate color. In the case of white, for example, if the light-emitting layer emits blue light, another light-emitting layer emits a color different from blue, that is, green or red. Furthermore, a third light-emitting layer that emits blue light and a charge-generating layer may be provided between the light-emitting layer or the laminated light-emitting layer in the present invention and the first or second electrode. The charge-generating layer exerts the function as a tandem element, and the electrons generated from the charge-generating layer and the holes injected from the first electrode are charge-recombined to generate excitons, and the holes generated from the charge-generating layer and the electrons injected from the second electrode are charge-recombined to form excitons. Therefore, the internal quantum efficiency is doubled. In this case, the organic light-emitting element of the present invention can be applied to one side of the tandem element as a blue light-emitting layer as a complementary color of yellow light emission. Therefore, a white light emitting device can be provided by forming a tandem device configuration with a blue light emitting layer made of the light emitting layer of the present invention and a yellow light emitting layer.

[0117] Specific examples of the device configuration of the organic light-emitting device of this embodiment include a multi-layer device configuration in which electrode layers and organic compound layers shown in (1) to (6) below are sequentially laminated on a substrate. In any device configuration, the organic compound layer necessarily includes a light-emitting layer having a light-emitting material. (1) Anode / light-emitting layer / cathode (2) Anode / hole transport layer / light emitting layer / electron transport layer / cathode (3) Anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (4) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode (5) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (6) Anode / hole transport layer / electron blocking layer / light emitting layer / hole blocking layer / electron transport layer / cathode

[0118] However, these device configuration examples are merely very basic device configurations, and are not limited to these. For example, various layer configurations can be adopted, such as providing an insulating layer, an adhesive layer, or an interference layer at the interface between the electrode and the organic compound layer, forming an electron transport layer or a hole transport layer from two layers having different ionization potentials, forming an emitting layer from two layers made of different emitting materials, and so on.

[0119] Among the device configurations shown in (1) to (6) above, the configuration (6) is preferred because it has both an electron blocking layer and a hole blocking layer. In other words, in the configuration (6) having an electron blocking layer and a hole blocking layer, both hole and electron carriers can be reliably confined within the light-emitting layer, resulting in an organic light-emitting device with no carrier leakage and high light-emitting efficiency.

[0120] In the organic light-emitting device of the present invention, all of the freely rotatable single bonds in the first to third organic compounds are carbon-carbon bonds, and further, in the second organic compound, at least one carbon of the carbon-carbon bonds is sp 2The organic compound is carbon. Therefore, the light-emitting layer composed of the first to third organic compounds has a stable molecular structure and has good durability. Therefore, it is preferable that the compounds of the electron blocking layer and the hole blocking layer in contact with the light-emitting layer also have a stable structure. For example, since the hole blocking layer needs to be stable against holes, it is preferable that the hole blocking layer compound is an organic compound with low reactivity, and furthermore, an organic compound consisting only of hydrocarbons. For example, since the electron blocking layer also needs to be stable against electrons, it is preferable that the compound of the hole blocking layer is an organic compound with low reactivity, and furthermore, an organic compound consisting only of hydrocarbons. For example, the electron blocking layer also needs to be stable against electrons, and therefore it is preferable that the compound of the hole blocking layer is an organic compound with low reactivity, and furthermore, all of the freely rotatable single bonds are carbon-carbon bonds, preferably sp 2 Carbon-sp 2 It is preferably an organic compound consisting of carbon bonds.

[0121] The mode of extraction (element form) of the light output from the light emitting layer may be a so-called bottom emission type in which light is extracted from the electrode on the substrate side, or a so-called top emission type in which light is extracted from the opposite side of the substrate. Also, a double-sided extraction type in which light is extracted from the substrate side and the opposite side of the substrate can be adopted.

[0122] <Other compounds> The first to third organic compounds according to the present invention can be used as a constituent material of an organic compound layer other than the light-emitting layer constituting the organic light-emitting device of the present embodiment. Specifically, they may be used as a constituent material of an electron transport layer, an electron injection layer, a hole transport layer, a hole injection layer, a hole blocking layer, etc. In this case, the emission color of the organic light-emitting device is not particularly limited. More specifically, it may be white or a neutral color.

[0123] In the organic light-emitting device according to the present embodiment, conventionally known low-molecular-weight and high-molecular-weight hole-injecting or hole-transporting compounds, host compounds, light-emitting compounds, electron-injecting or electron-transporting compounds, etc. may be used together as necessary. Examples of these compounds are given below.

[0124] As the hole injection transport material, a material having a high hole mobility is preferable so that the injection of holes from the anode can be easily performed and the injected holes can be transported to the light emitting layer. In addition, a material having a high glass transition temperature is preferable so as to suppress deterioration of the film quality such as crystallization in the organic light emitting device. Examples of low molecular weight and high molecular weight materials having hole injection transport performance include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. Furthermore, the above hole injection transport material is also preferably used in the electron blocking layer. Specific examples of compounds used as the hole injection transport material are shown below, but are not limited to these.

[0125] [ka]

[0126] Examples of the luminescent material mainly involved in the luminescent function include, in addition to the second organic compound described above, condensed ring compounds (e.g., fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetracene derivatives, anthracene derivatives, rubrene, etc.), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and polymer derivatives such as poly(phenylenevinylene) derivatives, poly(fluorene) derivatives, and poly(phenylene) derivatives. Specific examples of compounds used as the luminescent material are shown below, but are not limited to these.

[0127] [ka]

[0128] [ka]

[0129] The light-emitting layer may contain a fourth compound other than the first to third organic compounds as a host or assist. Examples of the fourth compound include, but are not limited to, aromatic hydrocarbon compounds or derivatives thereof, carbazole derivatives, azine derivatives, xanthone derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organic aluminum complexes such as tris(8-quinolinolato)aluminum, and organic beryllium complexes. Specific examples are shown below.

[0130] [ka]

[0131] The electron transporting material can be arbitrarily selected from those capable of transporting electrons injected from the cathode to the light-emitting layer, and is selected in consideration of the balance with the hole mobility of the hole transporting material. Examples of materials having electron transporting properties include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organic aluminum complexes, and condensed ring compounds (e.g., fluorene derivatives, naphthalene derivatives, chrysene derivatives, anthracene derivatives, etc.). Furthermore, the above electron transporting materials are also preferably used in the hole blocking layer. Specific examples of compounds used as electron transporting materials are shown below, but are of course not limited to these. Specific examples are shown below.

[0132] [ka]

[0133] The electron injection material can be selected from those that can easily inject electrons from the cathode, and is selected in consideration of the balance with hole injection properties. Organic compounds include n-type dopants and reducing dopants. For example, compounds containing alkali metals such as lithium fluoride, lithium complexes such as lithium quinolinol, benzimidazolidene derivatives, imidazolidene derivatives, fulvalene derivatives, and acridine derivatives can be mentioned. They can also be used in combination with the above electron transport materials.

[0134] <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 protective layer. The planarizing layer may be made of acrylic resin, etc. The same applies when a planarizing layer is provided between the color filter and the microlens.

[0135] [substrate] Examples of the substrate include quartz, glass, silicon wafer, resin, and metal. In addition, a switching element such as a transistor and wiring may be provided on the substrate, and an insulating layer may be provided thereon. As the insulating layer, any material can be used as long as it can form a contact hole so that wiring can be formed between the first electrode and the insulating layer, and insulation from wiring that is not connected can be ensured. For example, resin such as polyimide, silicon oxide, silicon nitride, etc. can be used.

[0136] [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.

[0137] The material constituting the anode should have as large a work function as possible. For example, metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, tungsten, etc., mixtures containing these metals, alloys combining these metals, metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide can be used. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0138] These electrode materials may be used alone or in combination of two or more kinds. The anode may be composed of one layer or multiple layers.

[0139] 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 serving as an electrode. When used as a transparent electrode, a transparent conductive layer of oxide such as indium tin oxide (ITO) or indium zinc oxide can be used, but is not limited to these. Photolithography technology can be used to form the electrode.

[0140] On the other hand, the material for the cathode should have a small work function. Examples of the material include alkali metals such as lithium, alkaline earth metals such as calcium, aluminum, titanium, manganese, silver, lead, chromium, and other metals or mixtures containing these metals. Alternatively, alloys combining these metals can be used. For example, magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, zinc-silver, and the like can be used. Metal oxides such as indium tin oxide (ITO) can also be used. These electrode materials may be used alone or in combination of two or more types. The cathode may have a single layer structure or a multi-layer structure. Among these, it is preferable to use silver, and it is even more preferable to use a silver alloy to reduce the aggregation of silver. As long as the aggregation of silver can be reduced, the ratio of the alloy is not important. For example, the ratio of silver to other metals may be 1:1, 3:1, and the like.

[0141] The cathode may be a top-emission element using an oxide conductive layer such as ITO, or a bottom-emission element using a reflective electrode such as aluminum (Al), and is not particularly limited. The method for forming the cathode is not particularly limited, but it is more preferable to use a direct current or alternating current sputtering method, etc., since the film coverage is good and the resistance can be easily reduced.

[0142] [Organic compound layer] The organic compound layer has at least a light-emitting layer, and may have a hole injection layer, a hole transport layer, and an electron blocking layer on the anode side, and a hole blocking layer, an electron transport layer, an electron injection layer, and the like on the cathode side, as necessary, by appropriately selecting them. The organic compound layer is mainly composed of an organic compound, but may contain inorganic atoms and inorganic compounds. For example, it may contain copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, zinc, and the like.

[0143] The organic compound layer constituting the organic light-emitting device according to one embodiment of the present invention can be formed by dry processes such as vacuum deposition, ionization deposition, sputtering, plasma, etc. Alternatively, instead of the dry process, a wet process can be used in which a layer is formed by dissolving the compound in an appropriate solvent and applying a known coating method (e.g., spin coating, dipping, casting, LB method, inkjet method, etc.). Here, when the layer is formed by a vacuum deposition method or a solution coating method, crystallization is unlikely to occur and the layer has excellent stability over time. When the layer is formed by a coating method, the layer can be formed by combining with a suitable binder resin.

[0144] 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. These binder resins may be used alone or in combination as homopolymers or copolymers, and may further include known additives such as plasticizers, antioxidants, and ultraviolet absorbers, if necessary.

[0145] [Protective layer] A protective layer may be provided on the second electrode. For example, by bonding glass provided with a moisture absorbent on the second electrode, it is possible to reduce the intrusion of water and the like into the organic compound layer and reduce 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 intrusion of water and the like into the organic compound layer. For example, after the second electrode is formed, it may be transported to another chamber without breaking the vacuum, and a silicon nitride film having a thickness of 2 μm may be formed by the CVD method to serve as a protective layer. A protective layer may be provided using an atomic deposition method (ALD method) after the film is formed by the CVD method. The material of the film formed by the ALD method is not limited, and may be silicon nitride, silicon oxide, aluminum oxide, etc. Silicon nitride may be further formed by the CVD method on the film formed by the ALD method. The film formed by the ALD method may have a smaller thickness than the film formed by the CVD method. Specifically, it may be 50% or less, or even 10% or less.

[0146] [Color Filter] A color filter may be provided on the protective layer. For example, a color filter taking into consideration the size of the organic light-emitting element may be provided on another substrate, and the substrate on which the organic light-emitting element is provided may be bonded to the color filter. Alternatively, a color filter may be patterned on the protective layer described above using a photolithography technique. The color filter may be made of a polymer.

[0147] [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 unevenness of the layer below. It may also be called a material resin layer without limiting the 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 is preferably a high molecular weight. The planarization layer may be provided above and below the color filter, and may be made of the same or different materials.Specific examples of the materials include polyvinylcarbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenol resin, epoxy resin, silicone resin, and urea resin.

[0148] [Microlens] The organic light-emitting element or the light-emitting device having the organic light-emitting element may have an optical member such as a microlens on the 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 the light-emitting device and 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 tangent and the hemisphere are the vertices of the microlens. The vertex of the microlens can be determined in the same manner in any cross-sectional view. That is, 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 tangent and the semicircle are the vertices of the microlens.

[0149] It is also possible to define the midpoint of the microlens. In the cross section of the microlens, a line segment is imaginary from a point where an arc shape ends to a point where another arc shape ends, and the midpoint of the 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.

[0150] [Opposite substrate] A counter substrate may be provided on the planarization layer. The counter substrate is called a counter substrate because it is provided at a position corresponding to the aforementioned substrate. The constituent material of the counter substrate may be the same as that of the aforementioned substrate. When the aforementioned substrate is a first substrate, the counter substrate may be a second substrate.

[0151] [Pixel circuit] The light-emitting device having the 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 a plurality of organic light-emitting elements independently. The active matrix type circuit may be voltage programming or current programming. The driving circuit has a pixel circuit for each pixel. The pixel circuit may have an organic light-emitting element, a transistor that controls the emission luminance of the organic light-emitting element, a transistor that controls the emission timing, a capacitance that holds the gate voltage of the transistor that controls the emission luminance, and a transistor for connecting to GND without passing through the light-emitting element.

[0152] The light-emitting device has a display region and a peripheral region arranged around the display region. The display region has a pixel circuit, and the peripheral region 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 characteristic of the transistor constituting the pixel circuit may be smaller than the slope of the current-voltage characteristic of the transistor constituting the display control circuit. The slope of the current-voltage characteristic can be measured by the so-called Vg-Ig characteristic. The transistor constituting the pixel circuit is a transistor connected to an organic light-emitting element.

[0153] [Pixels] A light emitting device having organic light emitting elements may have a plurality of pixels. Each pixel has sub-pixels that emit different colors. The sub-pixels may each emit, for example, RGB colors. The pixel emits light in an area also called the 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 the subpixels may be 10 μm or less, more specifically, it may be 8 μm, 7.4 μm, 6.4 μm. The pixels may have a known arrangement in plan view. For example, they may be a stripe arrangement, a delta arrangement, a pentile arrangement, or a Bayer arrangement. The shape of the subpixels in plan view may be any known shape. For example, they may be a rectangle, a quadrangle such as a diamond, or a hexagon. Of course, if the shape is not an exact figure but is close to a rectangle, it is included in the rectangle. The shape of the subpixels and the pixel arrangement may be used in combination.

[0154] <Applications of organic light-emitting devices> The organic light-emitting device according to the present 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, a light-emitting device having a white light source and a color filter, etc.

[0155] The display device may be an image information processing device having an image input unit that inputs image information from an area CCD, a linear CCD, a memory card, etc., an information processing unit that processes the input information, and displays the input image on a display unit. The display device may have a plurality of pixels, and at least one of the plurality of pixels may have the organic light-emitting element of this embodiment and a transistor connected to the organic light-emitting element. The display unit of the imaging device or inkjet printer may have a touch panel function. The driving method of the touch panel function may be an infrared type, a capacitance type, a resistive film type, or an electromagnetic induction type, and is not particularly limited. The display device may be used in the display unit of a multifunction printer.

[0156] Next, the display device according to the present embodiment will be described with reference to the drawings. FIG. 1(a) is an example of a pixel that is a component of the display device according to this embodiment. The pixel has sub-pixels 10. The sub-pixels are divided into 10R, 10G, and 10B according to their light emission. The emitted light color may be distinguished by the wavelength emitted from the light-emitting layer, or the light emitted from the sub-pixel may be selectively transmitted or color-converted by a color filter or the like. Each sub-pixel 10 has a reflective electrode that is a first electrode 2 on an interlayer insulating layer 1, an insulating layer 3 that covers the edge of the first electrode 2, an organic compound layer 4 that covers the first electrode 2 and the insulating layer 3, a transparent electrode that is a second electrode 5, a protective layer 6, and a color filter 7. 8 is an organic light-emitting element.

[0157] A transistor and a capacitance 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). The insulating layer 3 is also called a bank or a pixel separation film. It covers the ends of the first electrodes 2 and is disposed so as to surround the first electrodes 2. The portions where the insulating layer 3 is not disposed are in contact with the organic compound layer 4 and become light-emitting regions. The second electrode 5 may be a transparent electrode, a reflective electrode, or a semi-transparent electrode. The protective layer 6 reduces the penetration of moisture into the organic compound layer 4. The protective layer 6 is illustrated as being a single layer, but may be a multi-layer. Each layer may be an inorganic compound layer and an organic compound layer.

[0158] The color filters 7 are divided into 7R, 7G, and 7B according to their colors. The color filters 7 may be formed on a planarization layer (not shown). Also, a resin protective layer (not shown) may be provided on the color filters 7. Also, the color filters 7 may be formed on the protective layer 6. Alternatively, the color filters 7 may be provided on an opposing substrate such as a glass substrate and then bonded thereto.

[0159] FIG. 1(b) is a schematic 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 organic light-emitting element 26 and a TFT (thin film transistor) 18 as an example of the transistor are provided. A substrate 11 such as glass or silicon and an insulating layer 12 are provided on the upper part thereof. Active elements such as the TFT 18 are arranged on the insulating layer 12, and a gate electrode 13, a gate insulating film 14, and a semiconductor layer 15 of the active element are arranged. The TFT 18 is also composed of a drain electrode 16 and a source electrode 17. An insulating film 19 is provided on the upper part of the TFT 18. The anode 21 constituting the organic light-emitting element 26 and the source electrode 17 are connected through a contact hole 20 provided in the insulating film 19.

[0160] Note that the electrical connection method between the electrodes (anode 21, cathode 23) included in the organic light-emitting element 26 and the electrodes (source electrode 17, drain electrode 16) included in the TFT 18 is not limited to the mode shown in FIG. 1(b). That is, any one of the anode 21 or the cathode 23 and any one of the source electrode 17 or the drain electrode 16 of the TFT 18 may be electrically connected.

[0161] In the display device of FIG. 1(b), the organic compound layer 22 is illustrated as one layer, but the organic compound layer 22 may be a plurality of layers. A first protective layer 24 and a second protective layer 25 for reducing the deterioration of the organic light-emitting element 26 are provided on the cathode 23. Further, the transistor used in the display device of FIG. 1(b) is not limited to a transistor using a single crystal silicon wafer, and may be a thin film transistor having an active layer on an insulating surface of a substrate. Examples of the active layer include non-single crystal silicon such as single crystal silicon, amorphous silicon, and microcrystalline silicon, and non-single crystal oxide semiconductors such as indium zinc oxide and indium gallium zinc oxide.

[0162] The transistors included in the display device of Fig. 1(b) may be formed in a substrate such as a Si substrate. Here, "formed in a substrate" means that the substrate itself, such as a Si substrate, is processed to produce the transistors. In other words, having a transistor in a substrate can be seen as the substrate and the transistor being integrally formed.

[0163] The organic light-emitting element 26 according to this embodiment has its light emission brightness controlled by a TFT, which is an example of a switching element, and by providing the organic light-emitting element 26 on multiple surfaces, an image can be displayed based on the respective light emission brightnesses. The switching element according to this embodiment is not limited to a TFT, and may be a transistor formed of low-temperature polysilicon or an active matrix driver formed on a substrate such as a Si substrate. On the substrate can also be referred to as within the substrate. Whether to provide a transistor within the substrate or to use a TFT is selected according to the size of the display unit. For example, if the size is about 0.5 inches, it is preferable to provide the organic light-emitting element on a Si substrate.

[0164] 2 is a schematic diagram showing an example of a display device according to this embodiment. The display device 1000 has a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 between an upper cover 1001 and a lower cover 1009. Flexible printed circuits FPC1002 and 1004 are connected to the touch panel 1003 and the display panel. A transistor is printed on the circuit board 1007. The battery 1008 may not be provided if the display device is not a portable device, and may be provided in a different position if the display device is a portable device.

[0165] The display device according to this embodiment may have color filters having red, green, and blue colors, the red, green, and blue colors being arranged in a delta arrangement. 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 mobile phones such as smartphones, tablets, and head-mounted displays. The display device according to the present 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 may be a display unit disposed within a viewfinder. The imaging device may be a digital camera or a digital video camera.

[0166] 3(a) is a schematic diagram showing an example of an imaging device according to this embodiment. The imaging device 1100 may have a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 has a display device according to this embodiment. In this case, the display device may display not only an image to be captured, but also environmental information, imaging instructions, and the like. The environmental information may include the intensity of external light, the direction of external light, the moving speed of the subject, the possibility that the subject will be blocked by an obstruction, and the like.

[0167] Since the timing suitable for imaging is short, it is better to display information as soon as possible. Therefore, the display device using the organic light-emitting element of this embodiment is used. This is because the organic light-emitting element has a fast response speed. The display device using the organic light-emitting element is more suitable for use than liquid crystal display devices, which require a high display speed.

[0168] The imaging device 1100 has an optical section (not shown). The optical section has a plurality of lenses, which form an image on an imaging element housed in a housing 1104. The focus of the plurality of lenses can be adjusted by adjusting their relative positions. This operation can also be performed automatically. The imaging device may be called a photoelectric conversion device. The photoelectric conversion device can include an imaging method that does not capture images sequentially, but detects the difference from the previous image, cuts out an image from an image that is always recorded, and the like.

[0169] FIG. 3(b) is a schematic diagram showing an example of an electronic device according to the present embodiment. The electronic device 1200 has a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may have a circuit, a printed circuit board having the circuit, a battery, and a communication unit. The operation unit 1202 may be a button or a touch panel type reaction unit. The operation unit 1202 may be a biometric recognition unit that recognizes a fingerprint and performs unlocking or the like. An electronic device having a communication unit can also be called a communication device. The electronic device 1200 may further have a camera function by including a lens and an 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 notebook computer.

[0170] FIG. 4 is a schematic diagram showing an example of a display device according to the present embodiment. FIG. 4(a) shows a display device such as a television monitor or a PC monitor. The display device 1300 has a frame 1301 and a display unit 1302. The display unit 1302 uses the organic light-emitting element according to the present 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.

[0171] FIG. 4(b) is a schematic diagram showing another example of the display device according to the present embodiment. The display device 1310 in FIG. 4(b) is configured to be bendable, and is a so-called foldable display device. The display device 1310 has a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 have the organic light-emitting element according to the present embodiment. The first display unit 1311 and the second display unit 1312 may be a single display unit without a joint. The first display unit 1311 and the second display unit 1312 can be separated at the bending point. The first display unit 1311 and the second display unit 1312 may display different images, or the first and second display units may display one image.

[0172] FIG. 5(a) is a schematic diagram showing an example of a lighting device according to the present embodiment. The lighting device 1400 may have a housing 1401, a light source 1402, a circuit board 1403, an optical filter 1404 that transmits light emitted by the light source 1402, and a light diffusion unit 1405. The light source 1402 has an organic light-emitting element according to the present embodiment. The optical filter 1404 may be a filter that improves the color rendering of the light source. The light diffusion unit 1405 can effectively diffuse the light of the light source, such as for lighting up, and deliver the light over a wide range. The optical filter 1404 and the light diffusion unit 1405 may be provided on the light emission side of the lighting. If necessary, a cover may be provided on the outermost part.

[0173] The lighting device is, for example, a device that illuminates a room. The lighting device may emit white light, natural white light, or any other color from blue to red. It may have a dimming circuit that adjusts the light intensity. The lighting device may have the organic light-emitting element of this embodiment, and may further have a power supply circuit connected to the organic light-emitting element. The power supply circuit is a circuit that converts AC voltage into DC voltage. Moreover, white has a color temperature of 4200K, and natural white has a color temperature of 5000K. The lighting device may have a color filter. The lighting device according to the present embodiment may also include a heat dissipation section that dissipates heat from within the device to the outside, and examples of the heat dissipation section include metals with high specific heat, liquid silicone, and the like.

[0174] 5B is a schematic diagram of an automobile, which is an example of a moving body according to this embodiment. The automobile has tail lamps, which are an example of a lamp. The automobile 1500 has tail lamps 1501, and may be configured to turn on the tail lamps when braking or the like is performed. The tail lamp 1501 has an organic light-emitting element according to this embodiment. The tail lamp 1501 may have a protective member for protecting the organic light-emitting element. The protective member may be made of any material as long as it has a certain degree of strength and is transparent, but is preferably made of polycarbonate or the like. Polycarbonate may be mixed with a furandicarboxylic acid derivative, an acrylonitrile derivative, or the like.

[0175] The automobile 1500 may have a body 1503 and a window 1502 attached thereto. The window 1502 may be a transparent display unless it is a window for checking the front and rear of the automobile. The transparent display may have an organic light-emitting element according to this embodiment. In this case, the constituent materials of the electrodes and the like of the organic light-emitting element are made of transparent members.

[0176] The moving body according to the present embodiment may be a ship, an aircraft, a drone, or the like. The moving body may have a body and a lamp provided on the body. The lamp may emit light to indicate the position of the body. The lamp has the organic light-emitting element according to the present embodiment.

[0177] An application example of the display device of each of the above-mentioned embodiments will be described with reference to Fig. 6. The display device can be applied to a system that can be worn as a wearable device such as smart glasses, HMD, and smart contacts. An image capturing and display device used in such an application example has an image capturing device capable of photoelectrically converting visible light, and a display device capable of emitting visible light.

[0178] 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. 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 on the image capture device 1602.

[0179] FIG. 6(b) is a schematic diagram showing another example of a wearable device according to an embodiment of the present invention. Using FIG. 6(b), glasses 1610 (smart glasses) according to one application example will be described. The glasses 1610 have a control device 1612, and the control device 1612 is equipped with an imaging device corresponding to the imaging device 1602 in FIG. 6(a) and a display device. The lens 1611 is formed with an imaging device in the control device 1612 and an optical system for projecting light emitted from 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 controls the operations of the imaging device and the display device.

[0180] The control device 1612 may have a gaze detection unit that detects the gaze of the wearer. Infrared light may be used to detect the gaze. The infrared light emitting unit emits infrared light to the eyeball of the user gazing at the display image. The image capturing unit having a light receiving element detects the reflected light of the emitted infrared light from the eyeball to obtain an image of the eyeball. By providing a reduction means for reducing the light from the infrared light emitting unit to the display unit in a planar view, the deterioration of image quality is reduced. The gaze of the user to the display image is detected from the image of the eyeball obtained by capturing infrared light. Any known method can be applied to gaze detection using the image of the eyeball. As an example, a gaze detection method based on a Purkinje image due to reflection of irradiated light on the cornea can be used. More specifically, gaze detection processing based on a pupil-corneal reflex method is performed. Using the pupil-corneal reflex method, a gaze vector representing the direction (rotation angle) of the eyeball is calculated based on the image of the pupil and the Purkinje image included in the image of the eyeball, thereby detecting the gaze of the user.

[0181] A display device according to an embodiment of the present invention may have an imaging device having a light receiving element, and may control a display image of the display device based on the user's line of sight information from the imaging device. Specifically, the display device determines a first field of view area to which 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 received from an external control device. 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.

[0182] The display area includes a first display area and a second display area different from the first display area, and an area having a high priority 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 received from an external control device. The resolution of the area having a high priority may be controlled to be higher than the resolution of areas other than the area having a high priority. In other words, the resolution of an area having a relatively low priority may be lowered.

[0183] In addition, AI may be used to determine the first field of view area and the area with high priority. The AI ​​may be a model configured to estimate the angle of the line of sight and the distance to an object at the end of the line of sight from the image of the eyeball, using the image of the eyeball and the direction in which the eyeball in the image was actually looking as teacher data. The AI ​​program may be included in the display device, the imaging device, or an external device. If included in the external device, it is transmitted to the display device via communication. When display control is performed based on visual recognition detection, the present invention is preferably applicable to smart glasses that further include an imaging device for capturing images of the outside world. The smart glasses can display captured outside information in real time.

[0184] FIG. 7(a) is a schematic diagram showing an example of an image forming apparatus according to an embodiment of the present invention. The image forming apparatus 40 is an electrophotographic image forming apparatus, and 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 an organic light-emitting element according to this embodiment. The developing unit 31 includes a toner, etc. 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.

[0185] 7(b) and 7(c) are diagrams showing the exposure light source 28, and are schematic diagrams showing a state in which a plurality of light-emitting units 36 are arranged on a long substrate. The arrow 37 is a direction parallel to the axis of the photoconductor, and represents the column direction in which the light-emitting units 36 having 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 called the long axis direction of the photoconductor 27. FIG. 7(b) shows a form in which the light-emitting units 36 are arranged along the long axis direction of the photoconductor 27. FIG. 7(c) shows a form different from FIG. 7(b), in which the light-emitting units 36 are alternately arranged in the column direction in each of the first column and the second column. The first column and the second column are arranged at different positions in the row direction. In the first column, a plurality of light-emitting units 36 are arranged at intervals. In the second column, the light-emitting units 36 are arranged at positions corresponding to the intervals between the light-emitting units 36 in the first column. That is, a plurality of light-emitting units 36 are also arranged at intervals in the row direction. The arrangement in FIG. 7(c) can also be described as, for example, a grid-like arrangement, a houndstooth arrangement, or a checkerboard pattern.

[0186] As described above, by using a device using the organic light-emitting element according to this embodiment, it is possible to achieve a display with good image quality and stability even over a long period of time.

[0187] [Included configuration] The disclosure of this embodiment includes the following configuration. (Configuration 1) An organic light-emitting device having a first electrode, a light-emitting layer, and a second electrode, the light-emitting layer contains a first organic compound, a second organic compound, and a third organic compound; the first organic compound, the second organic compound, and the third organic compound each have a freely rotatable single bond that is a carbon-carbon bond; At least one carbon atom of a freely rotatable carbon-carbon bond contained in the second organic compound is sp 2 Carbon, An organic light-emitting element characterized in that, when the energy level of the HOMO of the first organic compound is HOMO1, the energy level of the LUMO of the second organic compound is LUMO2, and the energy levels of the HOMO and LUMO of the third organic compound are HOMO3 and LUMO3, the following [I] and [II] are satisfied. |LUMO2|>|LUMO3| [I] |HOMO3|>|HOMO1| [II]

[0188] (Configuration 2) The carbon atoms of the freely rotatable carbon-carbon bonds of the second organic compound are all sp 2 2. The organic light-emitting device according to configuration 1, characterized in that the organic light-emitting element is carbon. (Configuration 3) The carbon atoms of the freely rotatable carbon-carbon bonds contained in the first organic compound and the third organic compound are all sp 2 3. The organic light-emitting device according to configuration 1 or 2, characterized in that the organic material is carbon. (Configuration 4) The organic light-emitting element according to any one of structures 1 to 3, characterized in that the content of the first to third organic compounds in the light-emitting layer satisfies the relationship: third organic compound > first organic compound ≧ second organic compound. (Configuration 5) 5. The organic light-emitting device according to any one of configurations 1 to 4, wherein none of the first organic compound, the second organic compound, and the third organic compound has an alkyl group.

[0189] (Configuration 6) 6. The organic light-emitting device according to any one of configurations 1 to 5, wherein the second organic compound is a blue-emitting material. (Configuration 7) 7. The organic light-emitting device according to any one of configurations 1 to 6, wherein the second organic compound has a fluoranthene skeleton. (Configuration 8) The organic light-emitting element according to any one of structures 1 to 7, wherein the third organic compound has any one of an anthracene skeleton, a phenanthroline skeleton, a pyrene skeleton, a chrysene skeleton, a benzophenanthrene skeleton, a triphenylene skeleton, a fluoranthene skeleton, a benzochrysene skeleton, and a benzofluorane skeleton. (Configuration 9) 9. The organic light-emitting device according to any one of configurations 1 to 8, wherein the third organic compound has a pyrene skeleton.

[0190] (Configuration 10) 10. The organic light-emitting device according to any one of configurations 1 to 9, wherein the first organic compound is a compound represented by the following general formula [1]: [ka] [In the above general formula [1], R1 to R 26 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 may form a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 11 ~R 15 , R 20 ~R 24 may form a ring with adjacent substituents.

[0191] (Configuration 11) 10. The organic light-emitting device according to any one of configurations 1 to 9, wherein the first organic compound is a compound represented by the following general formula [2]: [ka]

[0192] [In the above general formula [2], R1 to R8 and R 27 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group, and n is a natural number selected from 1 to 3.

[0193] (Configuration 12) 10. The organic light-emitting device according to any one of structures 1 to 9, wherein the first organic compound is a compound represented by the following general formula [1-1] or [1-2]: [ka] [In the above general formula [1-1], R1 to R 26 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 At least one pair of R forms a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 11 ~R 15 , R 20 ~R 24 may form a ring with adjacent substituents. In the above general formula [1-2], R1 to R 38 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 18 ~R 19 , R 25 ~R 26 , R 28 may form a ring with adjacent substituents. (Configuration 13) 13. The organic light-emitting device according to claim 12, wherein the first organic compound is a compound represented by the following general formula [1-3]: [ka] [In the above general formula [1-3], R1 to R 26 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 At least one pair of R forms a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 11 ~R 15 , R 20 ~R 24 may form a ring with adjacent substituents.

[0194] (Configuration 14) The organic light-emitting element according to any one of structures 1 to 9, wherein the first organic compound is a compound having a skeleton represented by the following general formulas [3-1] to [3-4]. [ka] [In the above general formulas [3-1] to [3-4], the cyclic units A to C are each independently selected from an aromatic hydrocarbon group and a heterocyclic group, and may be condensed. Q1 to Q3 are each independently selected from a direct bond, CR1R2, NR3, an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. The substituents R1 to R3 are each independently selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group, and R3 may form a ring together with the adjacent cyclic units A to C.]

[0195] (Configuration 15) 15. The organic light-emitting element according to any one of structures 1 to 14, further comprising a hole-blocking layer in contact with the light-emitting layer, the hole-blocking layer being formed from a compound having a fused ring skeleton made of a hydrocarbon. (Configuration 16) 16. The organic light-emitting element according to any one of structures 1 to 15, further comprising an electron blocking layer in contact with the light-emitting layer, wherein the freely rotatable single bond of the compound constituting the electron blocking layer is a carbon-carbon bond. (Configuration 17) 17. The organic light-emitting element according to any one of Structures 1 to 16, further comprising a second light-emitting layer disposed in contact with the first light-emitting layer, the second light-emitting layer having an emission color different from that of the first light-emitting layer.

[0196] (Configuration 18) 18. A display device comprising a plurality of pixels, at least one of the plurality of pixels comprising an organic light-emitting element according to any one of structures 1 to 17 and a transistor connected to the organic light-emitting element. (Configuration 19) an optical unit having a plurality of lenses, an image sensor that receives light that has passed through the optical unit, and a display unit that displays an image captured by the image sensor; 18. A photoelectric conversion device, wherein the display section comprises the organic light-emitting element according to any one of configurations 1 to 17. (Configuration 20) 18. An electronic device comprising: a display unit having the organic light-emitting element according to any one of configurations 1 to 17; a housing in which the display unit is provided; and a communication unit provided in the housing and configured to communicate with an external device. (Configuration 21) 18. An illumination device comprising: a light source having the organic light-emitting element according to any one of configurations 1 to 17; and a light diffusion section or an optical filter that transmits light emitted by the light source. (Configuration 22) 18. A moving body comprising: a lighting fixture having the organic light-emitting element according to any one of configurations 1 to 17; and a body on which the lighting fixture is provided. (Configuration 23) 18. An exposure light source for an electrophotographic image forming apparatus, comprising the organic light emitting device according to any one of Configurations 1 to 17.

[0197] (Configuration 24) An organic compound represented by the following general formula [1-1] or [1-2]: [ka] [In the above general formula [1-1], R1 to R 26 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 At least one pair of R forms a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 11 ~R 15 , R 20 ~R 24 may form a ring with adjacent substituents. In the above general formula [1-2], R1 to R 38 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 18 ~R 19 , R 25 ~R 26 , R 28 may form a ring with adjacent substituents. (Configuration 25) 25. The organic compound according to claim 24, wherein the first organic compound is represented by the following general formula [1-3]: [ka] [In the above general formula [1-3], R1 to R 26 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 At least one pair of R forms a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 11 ~R 15 , R 20 ~R 24 may form a ring with adjacent substituents. EXAMPLES

[0198] The organic compounds used in this example are shown below.

[0199] [ka]

[0200] [ka]

[0201] [ka]

[0202] Table 7 shows the HOMO and LUMO levels of the organic compounds used in this example. The HOMO level is the value of the ionization potential of a 50 nm film of each organic compound prepared by vacuum deposition and measured using Riken Keiki's AC-3. The LUMO level is the value obtained by measuring the absorption spectrum of the thin film, determining the optical absorption edge as the band gap, and then subtracting it from the ionization potential.

[0203] [Table 7]

[0204] Example 1 In this example, an organic light-emitting element having a top-emission structure was produced in which an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode were successively formed on a substrate.

[0205] A 40 nm Ti film was formed on a glass substrate by sputtering, and then patterned using photolithography to form an anode. The electrode area of ​​the anode was 3 mm. 2 Then, the mixture was washed.

[0206] Next, the electrode-attached substrate prepared above was attached to a vacuum deposition apparatus (manufactured by ULVAC), and after preparing the deposition material, 1.33 × 10 -4 Pa(1×10 -6 The chamber was evacuated to a pressure of 1000 psi (1.5 Torr). The chamber was then cleaned with UV / ozone. Each layer was then formed in the layer configuration shown in Table 8 below. The substrate was then transferred to a glove box and sealed in a nitrogen atmosphere with a glass cap containing a desiccant to obtain an organic light-emitting device. "%" in the table means "% by mass."

[0207] [Table 8]

[0208] A voltage application device was connected to the obtained organic light-emitting device, and its characteristics were evaluated. The current-voltage characteristics were measured with a Hewlett-Packard microammeter 4140B, and the chromaticity was evaluated with a Topcon SR-3. The luminance was measured with a Topcon BM7. 2 The external quantum efficiency (EQE) during display was 5%, making it a satisfactory blue organic light-emitting device.

[0209] (Examples 2 to 26, Comparative Examples 1 to 6) Organic light-emitting devices were fabricated and their characteristics were evaluated in the same manner as in Example 1, except that the configuration of the organic compound layer was changed as shown in Tables 9 to 11. In the tables, "%" stands for "mass %." The element durability ratio is 5000cd / m 2 A continuous driving test was carried out at 40° C., and the luminance after 100 hours was measured. The luminance was expressed as a ratio with the luminance of the element of Comparative Example 1 taken as 1.0.

[0210] [Table 9]

[0211] [Table 10]

[0212] [Table 11]

[0213] <The effect of the freely rotatable single bond of the organic compound constituting the light-emitting layer being a carbon-carbon bond> Comparing Example 1 with Comparative Examples 1 to 3, the present invention, which is composed of only carbon-carbon bonds, showed better durability than Comparative Examples 1 to 3, which have carbon-nitrogen bonds as freely rotatable single bonds in the organic compound constituting the light-emitting layer. This is because the freely rotatable single bonds in the organic compound constituting the light-emitting layer in Example 1 are only carbon-carbon bonds, which have high bond energy and are less likely to decompose or react in an electric charge or excited state while the light-emitting element is in operation.

[0214] At least one carbon of the freely rotatable carbon-carbon bond of the second organic compound is sp 2 The effect of being carbon Comparing Examples 2 to 4 with Comparative Example 4, Example 4 having a methyl group in the second organic compound has better durability than Comparative Example 4 having a tert-butyl group, and Example 3 consisting of only aryl groups is also better. This is because the Examples having higher bond energy constituting the molecules of the organic compound constituting the light-emitting layer are less likely to decompose or react in the charge or excited state while the light-emitting element is in operation.

[0215] <Effect of the first organic compound's stable structure> Comparing Examples 1 and 5, Example 5 has better durability than Example 1. This is because Example 1 has an alkyl group in the first organic compound, while Example 5 is composed of only aryl groups, and therefore is less likely to decompose or react when placed in an electric charge or excited state during operation of the light-emitting element.

[0216] <Effect of the stable structure of the third organic compound> Comparing Examples 5 and 6, Example 6 has better durability than Example 5. This is because the third organic compound in Example 5 has an alkyl group, while the third organic compound in Example 6 is composed of only aryl groups, and therefore decomposition or reaction is less likely to occur in the charge or excited state while the light-emitting element is in operation.

[0217] <Hole-trapping effect of the first organic compound> Comparing Examples 8 and 9, Example 8 has better durability than Example 9. This is because the HOMO difference between the third organic compound and the first organic compound is 0.1 eV in Example 9 and 0.2 eV in Example 8, and Example 8 has a higher hole trapping property and a better carrier balance.

[0218] <Electron trapping effect of the second organic compound> Comparing Examples 6 and 13, Example 13 has better durability than Example 6. This is because the LUMO difference between the third organic compound and the first organic compound is 0.1 eV in Example 9 and 0.4 eV in Example 13, and Example 13 has a higher electron trapping property and a better carrier balance.

[0219] In the above examples, three organic compounds in which the freely rotatable single bond is a carbon-carbon bond were used as materials for the light-emitting layer, and the HOMO-LUMO relationship was adjusted. This resulted in the confinement of the charge within the light-emitting layer, suppression of the concentration of the recombination region, and stabilization of the molecular structure of the compound constituting the light-emitting layer, resulting in a highly durable organic light-emitting device.

[0220] Example 27 Exemplary compound Z-18 was synthesized according to the following reaction formula. [ka]

[0221] The following reagents and solvents were placed in a 50 ml recovery flask. Compound G1: 1.4g (3.9mmol) Compound G2: 1.4g (3.9mmol) Pd(PPh3)4: 0.23g (0.2mmol) Potassium carbonate: 2.7g Toluene: 20 ml Ethanol: 6ml H2O: 8ml

[0222] Next, the reaction solution was heated under reflux under nitrogen gas flow and stirred for 6 hours. After the reaction was completed, the mixture was concentrated, water was added and stirred, then filtered to collect the residue. The residue was dissolved in chlorobenzene, purified by column chromatography (chlorobenzene:heptane), and recrystallized from chlorobenzene / heptane to obtain 0.72 g (yield: 31%) of white solid G3. Mass spectrometry was performed on G3 using a MALDI-TOF-MS (Bruker Autoflex LRF). The measured value was m / z = 596, and the calculated value was C 41 H 23 Br=596.

[0223] The following reagents and solvents were placed in a 50 ml recovery flask. Compound G3: 0.50g (0.84mmol) Compound G4: 0.11g (0.92mmol) Pd(PPh3)4: 49 mg (0.04 mmol) Sodium carbonate: 0.6g Toluene: 10 ml Ethanol: 4ml H2O: 6ml

[0224] Next, the reaction solution was heated under reflux under nitrogen gas flow and stirred for 6 hours. After the reaction was completed, the mixture was filtered and the residue was collected. The residue was dissolved in chlorobenzene, purified by column chromatography (chlorobenzene:cyclohexane), and then recrystallized from toluene to obtain 0.25 g (yield: 51%) of Z-18 as a pale yellow solid. Mass spectrometry of Z-18 was performed using a MALDI-TOF-MS (Bruker Autoflex LRF). The measured value was m / z = 593, and the calculated value was C 47 H 28 =593.

[0225] (Examples 28 to 35) The exemplary compounds of Examples 28 to 35 were synthesized in the same manner as in Example 27, except that the raw materials G2 and G4 in Example 27 were changed to the compounds shown in Table 12. The actual measured values: m / z of the mass spectrometry results measured in the same manner as in Example 27 are shown in Table 12.

[0226] [Table 12]

[0227] In the above examples, three organic compounds in which the freely rotatable single bond is a carbon-carbon bond were used as materials for the light-emitting layer, and the HOMO-LUMO relationship was adjusted. This resulted in the confinement of the charge within the light-emitting layer, suppression of the concentration of the recombination region, and stabilization of the molecular structure of the compound constituting the light-emitting layer, resulting in a highly durable organic light-emitting device. [Explanation of symbols]

[0228] 2, 21: first electrode, 8, 26: organic light-emitting element, 5, 23: second electrode, 18: transistor, 1200: electronic device, 1201, 1302, 1311, 1312: display unit, 1203: housing, 1300, 1310: display device, 1400: lighting device, 1402: light source, 1404: optical filter, 1405: light diffusion unit

Claims

1. An organic light-emitting device having a first electrode, an emitting layer, and a second electrode, the light-emitting layer contains a first organic compound, a second organic compound, and a third organic compound; the first organic compound, the second organic compound, and the third organic compound each have a freely rotatable single bond that is a carbon-carbon bond; the second organic compound is a blue light-emitting material, An organic light-emitting element characterized by satisfying the following [I] and [II], when the HOMO energy level of the first organic compound is HOMO1, the LUMO energy level of the second organic compound is LUMO2, and the HOMO and LUMO energy levels of the third organic compound are HOMO3 and LUMO3. |LUMO2|>|LUMO3| [I] |HOMO3|>|HOMO1| [II] 2. The organic light-emitting device according to claim 1, wherein at least one carbon atom of the freely rotatable carbon-carbon bond contained in the second organic compound is an sp 2 carbon.

3. The carbon atoms of the freely rotatable carbon-carbon bonds of the second organic compound are all sp 2 3. The organic light-emitting device according to claim 2, wherein the organic material is carbon.

4. The carbon atoms of the freely rotatable carbon-carbon bonds contained in the first organic compound and the third organic compound are all sp 2 2. The organic light-emitting device according to claim 1, wherein the organic light-emitting element is carbon.

5. 2. The organic light-emitting element according to claim 1, wherein the contents of the first to third organic compounds in the light-emitting layer satisfy the following relationship: third organic compound > first organic compound ≥ second organic compound.

6. 2. The organic light-emitting device according to claim 1, wherein none of the first organic compound, the second organic compound, and the third organic compound has an alkyl group.

7. The organic light-emitting device according to claim 1 , wherein the second organic compound has a fluoranthene skeleton.

8. 2. The organic light-emitting element according to claim 1, wherein the third organic compound has any one of an anthracene skeleton, a phenanthroline skeleton, a pyrene skeleton, a chrysene skeleton, a benzophenanthrene skeleton, a triphenylene skeleton, a fluoranthene skeleton, a benzochrysene skeleton, and a benzofluorane skeleton.

9. The organic light-emitting element according to claim 1 , wherein the third organic compound has a pyrene skeleton.

10. 2. The organic light-emitting device according to claim 1, wherein the first organic compound is a compound represented by the following general formula [1]: 【Chemistry 1】 [In the above general formula [1], R 1 ~R 26 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 may form a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 11 ~R 15 , R 20 ~R 24 may form a ring with adjacent substituents.

11. 2. The organic light-emitting device according to claim 1, wherein the first organic compound is a compound represented by the following general formula [2]: 【Chemistry 2】 [In the above general formula [2], R 1 ~R 8 and R 27 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group, and n is a natural number selected from 1 to 3.

12. 2. The organic light-emitting device according to claim 1, wherein the first organic compound is a compound represented by the following general formula [1-1] or [1-2]: 【Transformation 3】 [In the above general formula [1-1], R 1 ~R 26 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 At least one pair of R forms a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 11 ~R 15 , R 20 ~R 24 may form a ring with adjacent substituents. In the above general formula [1-2], R 1 ~R 38 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 18 ~R 19 , R 25 ~R 26 , R 28 may form a ring with adjacent substituents.

13. 13. The organic light-emitting device according to claim 12, wherein the first organic compound is a compound represented by the following general formula [1-3]: 【Chemistry 4】 [In the above general formula [1-3], R 1 to R 38 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 15 and R 16 , R 19 and R 20 , R 24 and R 25 At least one pair of R to R forms a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 15 , R 20 ~R 24 may form a ring with adjacent substituents.

14. 2. The organic light-emitting device according to claim 1, wherein the first organic compound is a compound having a skeleton represented by any one of the following general formulas [3-1] to [3-4]. 【Transformation 5】 In the above general formulas [3-1] to [3-4], the cyclic units A to C are each independently selected from an aromatic hydrocarbon group and a heterocyclic group, and may be fused. 1 ~Q 3 is a direct bond, CR 1 R 2 , N.R. 3 , an oxygen atom, a sulfur atom, a selenium atom, and a tellurium atom. 1 ~R 3 are each independently selected from a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group; R 3 may form a ring with the adjacent cyclic units A to C.

15. 2. The organic light-emitting device according to claim 1, further comprising a hole-blocking layer in contact with the light-emitting layer, the hole-blocking layer being formed from a compound having a fused ring skeleton made of hydrocarbon.

16. 2. The organic light-emitting device according to claim 1, further comprising an electron-blocking layer in contact with the light-emitting layer, wherein the freely rotatable single bond of the compound constituting the electron-blocking layer is a carbon-carbon bond.

17. 2. The organic light-emitting element according to claim 1, further comprising a second light-emitting layer disposed in contact with the first light-emitting layer, the second light-emitting layer having an emission color different from that of the first light-emitting layer.

18. 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 1 and a transistor connected to the organic light-emitting element.

19. 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 1 .

20. 18. An electronic device comprising: a display unit having the organic light-emitting element according to claim 1; a housing in which the display unit is provided; and a communication unit provided in the housing and communicating with an external device.

21. 18. A lighting device comprising: a light source having the organic light-emitting element according to claim 1; and a light diffusion section or an optical filter that transmits light emitted by the light source.

22. A moving body comprising: a lamp having the organic light-emitting element according to claim 1; and a vehicle on which the lamp is provided.

23. An exposure light source for an electrophotographic image forming apparatus, comprising the organic light-emitting element according to claim 1 .

24. An organic compound represented by the following general formula [1-1]: 【Transformation 6】 [In the above general formula [1-1], R 1 ~R 26 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 10 and R 11 , R 15 and R 16 , R 19 and R 20 , R 24 and R 25 At least one pair of R forms a ring with a carbon atom as a spacer. 11 ~R 15 , R 20 ~R 24 may form a ring with adjacent substituents.

25. An organic compound represented by the following general formula [1-3]: 【Transformation 7】 [In the above general formula [1-3], R 1 to R 38 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group. 15 and R 16 , R 19 and R 20 , R 24 and R 25 At least one pair of R to R forms a ring with a carbon atom, an oxygen atom, a sulfur atom, a selenium atom, or a tellurium atom as a spacer. 15 , R 20 ~R 24 may form a ring with adjacent substituents.

Images