Organic light emitting element

Abstract

The present application relates to an organic light emitting element. An organic light emitting element comprising a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode. The organic compound layer comprises a light emitting layer comprising an organic compound and a light emitting material. When a permanent dipole moment of the organic compound is defined as μ h and a permanent dipole moment of the light emitting material is defined as μ d , μ h / μ d is 0.6 or more and 1.9 or less.

Description

Technical Field

[0001] This disclosure relates to an organic light-emitting element. Background Technology

[0002] An organic light-emitting element (hereinafter also referred to as an "organic electroluminescent element" or "organic EL element") is an electronic device having a pair of electrodes and an organic compound layer disposed between the electrodes. By injecting electrons and holes from the pair of electrodes, excitons of luminescent organic compounds are generated in the organic compound layer, and the organic light-emitting element emits light when the excitons return to the ground state.

[0003] Recent advances in organic light-emitting elements are significant; examples include low driving voltages, a wide range of emission wavelengths, high-speed response, and the possibility of making light-emitting devices thinner and lighter.

[0004] Chinese Patent Application Publication No. 114478588 (PTL1) describes an organic light-emitting element in which compounds 1-a and 1-b are used as the light-emitting layer.

[0005] Summary of the Invention

[0006] The organic light-emitting element according to this disclosure includes a first electrode, a second electrode, and an organic compound layer disposed between the first electrode and the second electrode, wherein the organic compound layer includes a light-emitting layer comprising an organic compound and a light-emitting material; the permanent dipole moment of the organic compound is defined as μ. h Furthermore, the permanent dipole moment of the luminescent material is defined as μ. d In the case of μ h / μ d It is above 0.6 and below 1.9.

[0007] The features of this disclosure will become apparent from the following description of the embodiments with reference to the accompanying drawings. The following description of the embodiments is illustrated by example. Attached Figure Description

[0008] Figure 1A This is a schematic cross-sectional view illustrating an example of pixels in a display device according to an embodiment of the present disclosure. Figure 1B This is a schematic cross-sectional view illustrating an example of a display device using organic EL elements according to an embodiment of the present disclosure.

[0009] Figure 2 This is a schematic diagram illustrating an example of a display device according to an embodiment of the present disclosure.

[0010] Figure 3A This is a schematic diagram illustrating an example of a camera device according to an embodiment of the present disclosure. Figure 3BThis is a schematic diagram illustrating an example of an electronic device according to an embodiment of the present disclosure.

[0011] Figure 4A This is a schematic diagram illustrating an example of a display device according to an embodiment of the present disclosure. Figure 4B This is a schematic diagram illustrating an example of a foldable display device.

[0012] Figure 5A This is a schematic diagram illustrating an example of a lighting device according to an embodiment of the present disclosure. Figure 5B This is a schematic diagram illustrating an example of a vehicle including a vehicle lighting device according to an embodiment of the present disclosure. Figure 5C This is a schematic diagram illustrating an example of the interior of a vehicle including a vehicle lighting device according to an embodiment of the present disclosure.

[0013] Figure 6A This is a schematic diagram illustrating an example of a wearable device according to an embodiment of the present disclosure. Figure 6B This is a schematic diagram illustrating an example of a wearable device according to an embodiment of the present disclosure, the wearable device including a camera device.

[0014] Figure 7A This is a schematic diagram illustrating an example of an image forming apparatus according to an embodiment of the present disclosure.

[0015] Figure 7B This is a schematic diagram illustrating an example of an exposure light source for an image forming apparatus according to an embodiment of the present disclosure. Figure 7C This is a schematic diagram illustrating an example of an exposure light source for an image forming apparatus according to an embodiment of the present disclosure.

[0016] Figure 8 A conceptual diagram showing the interaction between organic compounds and luminescent materials is presented in relation to the ratio of permanent dipole moments.

[0017] Figure 9 Show Figure 8 Legend in the diagram.

[0018] Figure 10 A schematic diagram illustrating charge quenching in a light-emitting element using exemplary compound A9 and compound 1-a is shown. Detailed Implementation

[0019] However, in the organic light-emitting elements described in PTL1, compound 1-a, which acts as the light-emitting material, and compound 1-b, which acts as the host material, have significant differences in permanent dipole moments, thus leaving room for improvement in luminous efficiency.

[0020] Therefore, this disclosure relates to providing an organic light-emitting element with excellent luminous efficiency.

[0021] Examples of halogen atoms in this specification include fluorine, chlorine, bromine, iodine, astatine, and... (tennessine), but not limited to this.

[0022] Alkyl groups can be alkyl groups having one or more but less than 20 carbon atoms, and can also be alkyl groups having one or more but less than 10 carbon atoms. Specific examples include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl, octyl, cyclohexyl, tert-pentyl, 3-methylpent-3-yl, 1-adamantyl, and 2-adamantyl.

[0023] An alkoxy group can be an alkoxy group having one or more but less than 20 carbon atoms, and can also be an alkoxy group having one or more but less than 10 carbon atoms. Specific examples include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, tert-butoxy, 2-ethyl-octoxy, and benzyloxy.

[0024] A silyl group is a group in which the silicon atom has a substituent. The substituent can be a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. The substituted or unsubstituted alkyl group of the silicon atom can be a substituted or unsubstituted alkyl group having one or more but less than four carbon atoms. The substituted or unsubstituted aryl group of the silicon atom can be a substituted or unsubstituted aryl group having six or more but less than ten carbon atoms. The silyl group can be a trialkylsilyl group, or a triarylsilyl group. Specific examples include, but are not limited to, trimethylsilyl and triphenylsilyl.

[0025] The aryl group can be an aryl group having 6 or more but less than 20 carbon atoms, an aryl group having 6 or more but less than 18 carbon atoms, or an aryl group having 6 or more but less than 12 carbon atoms. Specific examples include, but are not limited to, phenyl, biphenyl, naphthyl, phenanthrene, triphenylene, indene, terphenyl, fluorenyl, pyrene, anthracene, peryl, thionyl, and fluoranthracene.

[0026] A heteroaryl group can be a heteroaryl group having 3 or more but less than 24 carbon atoms, a heteroaryl group having 3 or more but less than 18 carbon atoms, or a heteroaryl group having 3 or more but less than 12 carbon atoms. Specific examples include, but are not limited to, pyridinyl, pyrazinyl, triazinyl, benzofuranyl, benzothiopheneyl, dibenzofuranyl, dibenzothiopheneyl, oxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl, carbazole, acridineyl, and phenanthrolinyl group.

[0027] The amino group can be a substituted amino group that is substituted with an alkyl or an aryl group, and can be a substituted amino group that is substituted with an alkyl group having one or more but less than four carbon atoms or an aryl group having six or more but less than twelve carbon atoms. Specific examples include, but are not limited to, N-methylamino, N-ethylamino, N,N-dimethylamino, N,N-diethylamino, N-methyl-N-ethylamino, N-benzylamino, N-methyl-N-benzylamino, N,N-dibenzylamino, aniline, N,N-diphenylamino, N,N-dinaphthylamino, N,N-difluorenylamino, N-phenyl-N-tolylamino, N,N-dimethylylamino, N-methyl-N-phenylamino, N,N-dianisinylamino, N-trimethylyl-N-phenylamino, N,N-ditrimethylylamino, N-phenyl-N-(4-tert-butylphenyl)amino, N-phenyl-N-(4-trifluoromethylphenyl)amino, and N-piperidinyl.

[0028] The aryloxy group can specifically be a phenoxy group, but is not limited to this.

[0029] Heteroaryloxy groups can specifically be thiophenoxy groups, but are not limited to these.

[0030] Examples of substituents that may be further present in the aforementioned alkyl, alkoxy, amino, aryloxy, silyl, aryl, heteroaryl, and heteroaryloxy groups include, for example, deuterium, alkyl such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl, aryl such as benzyl, aryl such as phenyl and biphenyl, heterocyclic such as pyridyl and pyrrole, amino such as dimethylamino, diethylamino, dibenzylamino, diphenylamino, and xylylamino, alkoxy such as methoxy, ethoxy, and propoxy, aryloxy such as phenoxy, halogen atoms such as fluorine, chlorine, bromine, and iodine, and cyano, but are not limited thereto.

[0031] (1) Organic light-emitting element

[0032] An organic light-emitting element (OLED) according to this disclosure will be described. The OLED according to this disclosure includes a first electrode, a second electrode, and an organic compound layer disposed between the electrodes. One of the first electrode and the second electrode is an anode, and the other is a cathode. The organic compound layer includes a light-emitting layer, and the light-emitting layer comprises an organic compound and a light-emitting material. In the OLED according to an embodiment of this disclosure, the light-emitting layer may be a layer comprising an organic compound, a light-emitting material, and compounds other than those described above. In the OLED according to an embodiment of this disclosure, the organic compound layer may be a single layer or a laminate comprising multiple layers, as long as it has a light-emitting layer.

[0033] In the organic light-emitting element according to this disclosure, the organic compound can be used as the host material of the light-emitting layer or as an auxiliary material. The light-emitting material can be used as a guest material or as an auxiliary material, but is preferably used as a guest material. When the light-emitting layer contains materials other than the organic compound and the light-emitting material, said materials can be used as auxiliary materials.

[0034] Here, the host material is also called the "host" or "first compound," and it is the compound with the highest mass ratio among the compounds constituting the luminescent layer. The guest material is also called the "guest," "dopant material," "dopant," or "third compound," and it is the compound constituting the luminescent layer whose mass ratio is lower than that of the host and which is primarily responsible for luminescence. Therefore, the guest material can also be called the luminescent material. The auxiliary material is also called the "auxiliary" or "second compound," and it is the compound constituting the luminescent layer whose mass ratio is lower than that of the host material and which assists the guest material in luminescence. Note that the auxiliary material is also called the second host.

[0035] Let S1(H) represent the lowest singlet excitation energy of the host material, S1(D) represent the lowest singlet excitation energy of the guest material, and S1(A) represent the lowest singlet excitation energy of the auxiliary material.

[0036] In this case, the organic light-emitting element according to this embodiment preferably satisfies S1(H)>S1(D) or S1(H)>S1(A)>S1(D). When the lowest singlet excitation energy of the compound contained in the organic light-emitting element according to this embodiment satisfies the above relationship, excitons can be effectively transferred to the guest material, resulting in the organic light-emitting element having superior luminous efficiency.

[0037] The concentration of the main material relative to the entire light-emitting layer can be 50% by mass or more and less than 99% by mass, preferably 50% by mass or more and less than 98% by mass, more preferably 50% by mass or more and less than 95% by mass, and even more preferably 50% by mass or more and less than 90% by mass.

[0038] The concentration of the guest material relative to the entire luminescent layer can be above 0.1% by mass and below 30% by mass, above 0.1% by mass and below 20% by mass, or above 0.1% by mass and below 10.0% by mass.

[0039] When the light-emitting layer further comprises auxiliary materials, the concentration of the auxiliary materials relative to the entire light-emitting layer can be 1% by mass or more and less than 50% by mass, preferably 10% by mass or more and less than 50% by mass. The concentration of the object can be 0.01% by mass or more and less than 20% by mass, and preferably 0.01% by mass or more and less than 5% by mass.

[0040] Here, when the organic compound layer is a stack comprising multiple layers, in addition to the luminescent layer, the organic compound layer may further include a hole injection layer, a hole transport layer, an electron blocking layer, a hole-exciton blocking layer, an electron transport layer, and an electron injection layer. The luminescent layer can be a single layer or a stack comprising multiple layers. When the luminescent layer comprises multiple layers, a charge generation layer can be disposed between the luminescent layers. The charge generation layer can be formed by a compound whose LUMO (lowest unoccupied molecular orbital) energy level is lower than the HOMO energy level of the hole transport layer, and the LUMO energy level of the charge generation layer can be lower than the HOMO energy level of the hole transport layer. Here, the HOMO energy level and LUMO energy level of the organic compound layer can be the HOMO energy level and LUMO energy level of the organic compound with the highest weight ratio in the organic compound layer.

[0041] Specific examples of the element configuration of the organic light-emitting element according to this embodiment include the following (1) to (6) in which an electrode layer and an organic compound layer are stacked sequentially on a substrate to form a multilayer element configuration.

[0042] (1) Anode / Light-emitting layer / Cathode

[0043] (2) Anode / Hole transport layer / Light emission layer / Electron transport layer / Cathode

[0044] (3) Anode / Hole transport layer / Light emission layer / Electron transport layer / Electron injection layer / Cathode

[0045] (4) Anode / Hole Injection Layer / Hole Transport Layer / Light Emitting Layer / Electron Transport Layer / Cathode

[0046] (5) Anode / Hole Injection Layer / Hole Transport Layer / Light Emitting Layer / Electron Transport Layer / Electron Injection Layer / Cathode

[0047] (6) Anode / Hole Transport Layer / Electron Blocking Layer / Light Emitting Layer / Hole Blocking Layer / Electron Transport Layer / Cathode

[0048] However, these examples of component configurations are only very basic and are not limiting examples. For example, various layer configurations can be used: an insulating layer, adhesive layer, or interference layer can be arranged at the interface between the electrode and the organic compound layer; an electron transport layer or hole transport layer can be composed of two layers with different ionization potentials; and a light-emitting layer can be composed of two layers formed of different light-emitting materials.

[0049] Of the above-described element configurations (1) to (6), configuration (6) is preferred because it has both an electron blocking layer and a hole blocking layer. Specifically, in configuration (6) which has both an electron blocking layer and a hole blocking layer, both electron and hole carriers can be reliably confined within the light-emitting layer, thereby providing an organic light-emitting element that does not have carrier leakage and has high luminous efficiency.

[0050] The light extraction mode (element form) emitted from the light-emitting layer can be a so-called bottom emission mode in which light is extracted from electrodes on the substrate side, or a so-called top emission mode in which light is extracted from the opposite side of the substrate. Alternatively, a dual-sided extraction mode in which light is extracted from both the substrate side and the opposite side of the substrate can also be used.

[0051] Here, when the HOMO and LUMO levels are closer to the vacuum level, they are referred to as "high". The fact that the LUMO level of the charge generation layer is lower than the HOMO level of the hole transport layer means that the LUMO level of the charge generation layer is farther from the vacuum level than the HOMO level of the hole transport layer.

[0052] In this specification, molecular orbital calculations can be used to calculate HOMO and LUMO energy levels.

[0053] In this specification, HOMO and LUMO energy levels can also be calculated using ionization potential and band gap. HOMO energy levels can be estimated by measuring ionization potential. Ionization potential can be measured by dissolving the compound to be measured in a solvent such as toluene or by forming a vapor-deposited film of the compound on a substrate made of glass or the like, and then measuring it using a measuring device such as an AC-3. Band gap can be measured by dissolving the compound to be measured in a solvent such as toluene and measuring it by irradiation with excitation light. Band gap can be measured by measuring the absorption edge of the excitation light's absorption spectrum. Alternatively, band gap can be measured by vapor-depositing the compound to be measured on a substrate made of glass or the like and irradiating the vapor-deposited film with excitation light. Band gap can be measured by measuring the absorption edge of the absorption spectrum in which the vapor-deposited film absorbs the excitation light.

[0054] The LUMO level can be calculated using the band gap and ionization potential values. The LUMO level can be estimated by subtracting the ionization potential from the band gap.

[0055] The LUMO level can also be estimated from the reduction potential. For example, the single-electron reduction potential can be estimated using cyclic voltammetry (CV). CV measurements can be performed, for example, in a 0.1 M tetrabutylammonium perchlorate DMF solution using Ag / Ag. + The reference electrode, the counter electrode of Pt, and the working electrode of glassy carbon were used.

[0056] For the determined reduction potential of the compound, the difference with the reduction potential of ferrocene is added to -4.8 eV to estimate the LUMO level.

[0057] The luminescent layer can be a single layer or multiple layers; when it contains luminescent materials with other luminescent colors, it can provide white or intermediate colors, etc. Multiple layers refer to the state in which the luminescent layer and other luminescent layers are stacked. In this case, the luminescent color of the organic light-emitting element is not limited to blue. These films are formed by vapor deposition or coating.

[0058] The organic light-emitting element according to this disclosure will be described in detail below.

[0059] The organic light-emitting element according to this disclosure has the following characteristics and therefore has excellent durability.

[0060] (1-1) The ratio of the permanent dipole moment of the organic compound to that of the luminescent material is greater than 0.6 and less than 1.9.

[0061] This feature will be described below.

[0062] (1-1) The ratio of the permanent dipole moment of the organic compound to that of the luminescent material is greater than 0.6 and less than 1.9.

[0063] In the organic light-emitting element according to this disclosure, when the permanent dipole moment of the organic compound is defined as μ h Furthermore, the permanent dipole moment of the luminescent material is defined as μ. d At that time, μ h / μ d It is above 0.6 and below 1.9.

[0064] This characteristic facilitates energy transfer between the organic compound and the luminescent material, thus providing an organic light-emitting element with excellent luminescent efficiency. In this case, for μ... h There are no particular restrictions on the value of μ, and h It can be greater than 0.10, and it can be greater than 0.12. μ h It can be below 3.0, below 2.67, below 1.67, below 1.0, below 0.89, below 0.60, and below 0.53. μ h / μ d It can be above 0.6 and below 1.8, and it can also be above 0.6 and below 1.2.

[0065] As a means to promote energy transfer in the luminescent layer of an organic light-emitting element, the inventors focus on the relationship between the permanent dipole moments of organic compounds and luminescent materials. Figure 8A conceptual diagram illustrating the interaction between organic compounds and luminescent materials is shown, relating it to the ratio of permanent dipole moments. Figure 9 Show Figure 8 Legend in the diagram.

[0066] exist Figure 8 In the present disclosures 1 and 2, the organic light-emitting elements have a configuration in which the ratio of the permanent dipole moments of the organic compound and the light-emitting material is 0.6 or more and 1.9 or less. In other words, the organic light-emitting elements according to the present disclosures 1 and 2 have a configuration in which the values ​​of the permanent dipole moments of the organic compound and the light-emitting material are close. Here, an organic compound with a large permanent dipole moment refers to an organic compound in which charge shift (δ+ or δ-) occurs in the molecule, and an organic compound with a small permanent dipole moment refers to an organic compound in which charge shift is unlikely to occur in the molecule.

[0067] In this disclosure 1, both the organic compound and the luminescent material are compounds with large permanent dipole moments and undergo charge shifts within their molecules. Interactions tend to occur between the δ- atoms of the organic compound and the δ+ atoms of the luminescent material, as well as between the δ+ atoms of the organic compound and the δ- atoms of the luminescent material, thereby improving the compatibility between the organic compound and the luminescent material. As a result, the intermolecular distance between the organic compound and the luminescent material is shortened, which in this embodiment facilitates energy transfer from the organic compound to the luminescent material and improves luminous efficiency. In this disclosure 2, both the organic compound and the luminescent material are compounds with small permanent dipole moments and are less likely to undergo charge shifts within their molecules. Therefore, the organic compound and the luminescent material readily interact with each other, thereby improving the compatibility between them.

[0068] As a result, the intermolecular distance between the organic compound and the luminescent material is shortened, the energy transfer from the organic compound to the luminescent material is promoted, and the luminescence efficiency is improved.

[0069] On the other hand, when the intermolecular distance between the organic compound and the luminescent material increases, the energy transfer from the organic compound to the luminescent material decreases. As a result, the excitons of the organic compound are deactivated before moving to the luminescent material, leading to a decrease in luminescence efficiency. The organic light-emitting element according to Comparative Example 1 has a configuration in which the permanent dipole moment of the organic compound is small and the permanent dipole moment of the luminescent material is large. The organic light-emitting element according to Comparative Example 2 has a configuration in which the permanent dipole moment of the organic compound is large and the permanent dipole moment of the luminescent material is small. These organic light-emitting elements have a configuration in which one of the permanent dipole moments of the organic compound and the luminescent material is large; therefore, when the compounds interact with each other, the δ+ and δ- of the compound with the large permanent dipole moment interact with each other. In other words, in the configuration of Comparative Example 1, the interaction between the luminescent materials is large, and in the configuration of Comparative Example 2, the interaction between the organic compounds is large, resulting in a decrease in the compatibility between the organic compound and the luminescent material. Therefore, the intermolecular distance between the organic compound and the luminescent material increases, and the energy transfer efficiency decreases. As a result, the excitons of the organic compound are deactivated before moving to the luminescent material, leading to a decrease in luminescence efficiency.

[0070] For the reasons stated above, organic light-emitting elements in which the permanent dipole moments of the organic compound and the luminescent material are close in value are organic light-emitting elements with excellent luminous efficiency.

[0071] Furthermore, the organic light-emitting element according to this disclosure also exhibits excellent element durability. The permanent dipole moments of the organic compound and the luminescent material are close, making it easy for them to interact with each other. In the organic light-emitting element according to this disclosure, compared to the organic light-emitting element according to the comparative example, the interaction between organic compounds can be reduced, thereby eliminating local charge accumulation and suggesting that quencher generation is suppressed. As a result, the organic light-emitting element according to this embodiment also exhibits excellent element durability.

[0072] Table 1 describes the device efficiency ratio and device durability ratio of the organic light-emitting element according to the present disclosure and the organic light-emitting element according to the comparative example. The organic light-emitting element according to the comparative example is the organic light-emitting element described in PTL1.

[0073] The element efficiency ratio is the ratio of the luminous efficiency of the organic light-emitting element according to Comparative Example 1; and the element durability ratio is the ratio of the time it takes for the brightness of the organic light-emitting element according to Comparative Example 1 to decrease to 95% of its initial brightness, and is a value indicating durability.

[0074] Table 1

[0075]

[0076] According to this disclosure, the organic light-emitting element is wherein μ h / μ d The organic light-emitting element has a μ value of 0.6 or more and 1.9 or less; and the organic light-emitting element according to the comparative example is wherein μ h / μ d Organic light-emitting elements (OLEDs) with a permanent dipole moment less than 0.6 or greater than 1.9, wherein the permanent dipole moment of the luminescent material is greater than that of the organic compound. Table 1 shows the configuration of the OLEDs according to this disclosure having excellent element efficiency. This is presumably because, as mentioned above, the permanent dipole moments of the organic compound and the luminescent material are close, making them easily dispersed in the film to facilitate energy transfer from the organic compound to the luminescent material.

[0077] As described above, the organic light-emitting element according to this disclosure is an organic light-emitting element with excellent luminous efficiency. Furthermore, the organic light-emitting element according to this embodiment is also an organic light-emitting element with excellent durability.

[0078] Note that molecular orbital calculations are used to calculate the permanent dipole moment. The computational technique used for molecular orbital calculations is density functional theory (DFT), which is widely adopted. The functional is B3LYP, and the basis set is 6-31G. For example, the scientists have been able to generate a range of Gaussian09 (Gaussian09, C.01, MJ Frisch, GWTrucks, HB Schlegel,MA Robb,G.Mennucci,H.Caricato,AF,Zheng Sonnenberg,M.Toyoda,M.Ishida,O.Kitao,J.E. Ogliaro,JJ Brothers,KN Kudin,T Kobayashi,K Raghavachari,JC Burant,M. Cossi,JM Klene,JB Cross,J Jaramillo,R Yazyev,JW Ochterski,K Morokuma,P Salvador,S Dapprich,O Farkas,JV Ortiz,DJ Fox,Gaussian,Inc.,Wallingford CT,2010.)Publishers.In the following text, the molecular orbital calculations in this specification are performed using the same technique.

[0079] Furthermore, the organic light-emitting element of this embodiment preferably has the following characteristics:

[0080] (1-2) Organic compounds include fused polycyclic hydrocarbon rings having more than three rings and less than four rings;

[0081] (1-3) Organic compounds contain indole-carbazole skeleton and pyrene skeleton;

[0082] (1-4) Organic compounds comprising an indole-carbazole skeleton in which a substituent is disposed at the meta position relative to the nitrogen atom; or

[0083] (1-5) The luminescent material emits fluorescence.

[0084] These will be described below.

[0085] (1-2) Organic compounds containing fused polycyclic aromatic hydrocarbons having three or more rings but fewer than four rings.

[0086] In the organic light-emitting element according to this embodiment, the organic compound preferably has a fused polycyclic hydrocarbon ring having three or more rings and four or fewer rings. Non-limiting specific examples include anthracene skeletons, pyrene skeletons, and tetraphenyl benzoxene skeletons. These skeletons tend to exhibit low minimum triplet excitation energies (T1) and can improve the efficiency of converting triplet excited states to singlet excited states, thereby enabling superior luminescence efficiency.

[0087] The organic compound according to this embodiment may further comprise a fused polycyclic hydrocarbon ring having 10 or more but less than 30 carbon atoms. The fused polycyclic hydrocarbon ring having 10 or more but less than 30 carbon atoms is preferably a fused polycyclic hydrocarbon ring having 3 or more but less than 6 rings. Specifically, the ring preferably has an anthracene skeleton, phenanthrene skeleton, fluorene skeleton, pyrene skeleton, triphenylene skeleton, fluorene skeleton, fluoranthene skeleton, tetraphenylene skeleton, chrysene skeleton, perylene skeleton, or spirofluorene skeleton, more preferably an anthracene skeleton or pyrene skeleton, and even more preferably a pyrene skeleton.

[0088] Compounds containing anthracene or pyrene skeletons have low T1 and provide higher efficiency in converting triplet excited states to singlet excited states; therefore, organic light-emitting elements using compounds containing such skeletons have superior luminous efficiency and are therefore preferred. Furthermore, compounds containing pyrene skeletons exhibit excellent oxidative stability; therefore, organic light-emitting elements using these compounds also have superior durability and are therefore preferred.

[0089] (1-3) Organic compounds contain indole-carbazole and pyrene skeletons.

[0090] In the organic light-emitting element according to this embodiment, the organic compound preferably comprises an indolocarbazole backbone and a pyrene backbone. When an organic compound having these backbones is used, the permanent dipole moment of the molecule increases, thus the luminous efficiency of the organic light-emitting element according to this embodiment is superior.

[0091] The organic compound in the organic light-emitting element according to this embodiment is preferably represented by any one of general formulas (1) to (3), and the organic compound represented by general formula (1) is more preferably represented by general formula (1-2).

[0092]

[0093] Compared to the pyrene skeleton, the organic compound according to this embodiment comprises an indolocarbazole skeleton as an aromatic heterocycle on one side, and a hydrogen atom, a deuterium atom, an aromatic hydrocarbon ring, or a combination of aromatic hydrocarbon rings on the other side. Therefore, the molecule as a whole has an indolocarbazole skeleton as an aromatic heterocycle at one end and a hydrocarbon structure at the other end. Consequently, in the organic compound according to this embodiment, polarization occurs within the molecule, resulting in a higher permanent dipole moment, and consequently, exhibiting excellent luminescence efficiency.

[0094] Figure 10 A schematic diagram illustrating charge quenching in a light-emitting element using exemplary compound A9 and compound 1-a is shown.

[0095] exist Figure 10 In this compound, compound 1-a is a compound with low intramolecular polarization, and when an exciton is generated at the center of the molecule, electrons and holes can easily approach the exciton, thus making it more susceptible to quenching than the organic compounds according to this embodiment.

[0096] On the other hand, in the exemplary compound A9, when excitons are generated at the center of the molecule, electrons (anions) and holes (cations) approaching the molecule are located near the δ+ and δ- portions of the molecule, respectively. As a result, the excitons and electrons or holes are located in portions far apart from each other, making it possible to suppress the deactivation (quenching) of excitons passing through electrons or holes, thereby providing an organic light-emitting element with excellent luminescence efficiency.

[0097] Here, the effect of separating the exciton-generating site from the site of proximity of electrons or holes is described. Before the exciton transitions to the ground state and when the exciton approaches an electron or hole within a certain distance, the exciton is quenched, and the luminescence efficiency decreases. Therefore, to suppress exciton quenching, it is necessary to separate the exciton-generating site from the site of proximity of electrons or holes to the molecule. The organic compound according to this embodiment has high intramolecular polarization, thus electrons or holes approach sites far from the molecular center. As a result, the exciton generated at the molecular center is separated from the electron or hole, thereby suppressing exciton quenching.

[0098] Therefore, the organic light-emitting element according to this embodiment contains an organic compound represented by any of the general formulas (1) to (3), resulting in superior luminous efficiency.

[0099] The organic compound according to this embodiment preferably contains a freely rotatable single bond as a carbon-carbon bond with high bond energy. In particular, the durability of organic compounds represented by general formulas (1) to (3) containing a freely rotatable single bond as a carbon-carbon bond with high bond energy is also superior. Therefore, the durability of organic light-emitting elements using organic compounds represented by general formulas (1) to (3) is also superior.

[0100] In this specification, a rotatable single bond refers to a single bond between unit A and unit B, denoted as "AB", where unit A and unit B are not cyclically fused together. Units A and B can each be atoms such as carbon or nitrogen atoms, or molecules such as benzene or carbazole.

[0101] The general formulas (1) to (3) will be described below.

[0102] R1 to R 17 R 21 To R 38 and R 41 To R 58

[0103] R1 to R 17 R 21 To R 38 and R 41 To R 58 Each is independently selected from the group consisting of: hydrogen atom, deuterium atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted silyl group, substituted or unsubstituted amino group, and cyano group.

[0104] R1 to R 17Each of the following can be independently selected: hydrogen atom, deuterium atom, substituted or unsubstituted alkyl group having one or more but six or fewer carbon atoms, substituted or unsubstituted alkoxy group having one or more but four or fewer carbon atoms, and trimethylsilyl group. Specifically, R1 to R 17 Each of the following groups can be independently selected: hydrogen atom, deuterium atom, methyl, CD3 group, isopropyl, tert-butyl, cyclohexyl, methoxy, and trimethylsilyl.

[0105] R3 and R6 can be hydrogen atoms, R1 to R... 19 It can be a hydrogen atom, or R1 to R 19 It can be a deuterium atom.

[0106] Here, when R1 to R 17 When at least one of them is a substituent other than a hydrogen atom, R3, R5, R6, R 12 and R 16 At least one of them can be a substituent, or R3 and R5, R6, or R 12 and R 16 It can be a substituent. When R 21 To R 38 When at least one of them is a substituent other than a hydrogen atom, R 21 R 22 R 29 R 32 and R 36 At least one of them can be a substituent. When R 41 To R 58 When at least one of them is a substituent other than a hydrogen atom, R 43 R 45 R 46 R 52 and R 56 At least one of them can be a substituent.

[0107] Ar1 bonded to R 11 To R 19 Any one of them, preferably bonded to R 13 R 16 and R 19 Any one of them, more preferably bonded to R 19 .

[0108] Here, for example, "Ar1 bonded to R" 19 This means that Ar1 is directly bonded to R. 19 The bonded carbon atoms, specifically referring to the structure represented by general formula (1-2).

[0109] Ar1, Ar3 and Ar5

[0110] Ar1, Ar3, and Ar5 are each independently selected from the following groups: aromatic hydrocarbon rings, aromatic heterocycles, and combinations thereof. Aromatic hydrocarbon rings may have substituents.

[0111] When the organic compound according to this disclosure has Ar1 (n is 1), Ar1 can be an aromatic hydrocarbon ring having 6 or more but less than 30 carbon atoms, an aromatic heterocycle having 3 or more but less than 15 carbon atoms, or a combination thereof.

[0112] Ar1, Ar3, and Ar5 can be aromatic hydrocarbon rings with 6 or more but less than 30 carbon atoms, aromatic heterocycles with 3 or more but less than 15 carbon atoms, combinations of aromatic hydrocarbon rings with 6 or more but less than 10 carbon atoms and aromatic heterocycles with 3 or more but less than 9 carbon atoms, combinations of aromatic hydrocarbon rings with 6 or more but less than 10 carbon atoms and aromatic hydrocarbon rings with 6 or more but less than 10 carbon atoms, or combinations of aromatic heterocycles with 3 or more but less than 9 carbon atoms and aromatic heterocycles with 3 or more but less than 9 carbon atoms. Specific examples include benzene rings, phenanthrene rings, triphenylene rings, cyclopentadiene rings, spirofluorene rings, fluorene rings, pyridine rings, thiophene rings, furan rings, dibenzofuran rings, dibenzothiophene rings, quinoline rings, combinations of benzene rings and benzene rings (biphenyl), combinations of naphthylene rings and benzene rings, combinations of thiophene rings and thiophene rings, combinations of benzene rings and pyridine rings, combinations of benzene rings and oxazole rings, and combinations of benzene rings and thiazole rings.

[0113] Ar1, Ar3, and Ar5 can be aromatic hydrocarbon rings with 6 or more but less than 25 carbon atoms, aromatic heterocycles with 3 or more but less than 12 carbon atoms, combinations of aromatic hydrocarbon rings with 6 or more but less than 10 carbon atoms and aromatic heterocycles with 3 or more but less than 5 carbon atoms, combinations of aromatic hydrocarbon rings with 6 or more but less than 10 carbon atoms and aromatic hydrocarbon rings with 6 or more but less than 10 carbon atoms, or combinations of aromatic heterocycles with 3 or more but less than 5 carbon atoms and aromatic heterocycles with 3 or more but less than 5 carbon atoms.

[0114] Ar1, Ar3, and Ar5 can be aromatic hydrocarbon rings having 5 or more but less than 15 carbon atoms or aromatic heterocycles having 3 or more but less than 12 carbon atoms. Specific examples include benzene rings, pyridine rings, dibenzofuran rings, dibenzothiophene rings, and fluorene rings, with preferred examples including benzene rings, dibenzofuran rings, dibenzothiophene rings, and fluorene rings.

[0115] When Ar1, Ar3, and Ar5 have substituents, the substituents may be deuterium atoms, substituted or unsubstituted alkyl groups, substituted or unsubstituted alkoxy groups, substituted or unsubstituted silyl groups, substituted or unsubstituted amino groups, or cyano groups. The substituents are preferably deuterium atoms, substituted or unsubstituted alkyl groups having one or more but four or fewer carbon atoms, or aryl groups having six or more but ten or fewer carbon atoms; more preferably, substituted or unsubstituted alkyl groups having one or more but four or fewer carbon atoms, or aryl groups having six or more but ten or fewer carbon atoms. Specifically, the substituents are preferably one or more methyl or phenyl groups, more preferably one or more methyl groups.

[0116] Ar1, Ar3, and Ar5 are preferably more concentrated than sp 3 More carbon sp 2 The number of carbon atoms, more preferably only by sp 2 The structure is composed of carbon. Furthermore, when Ar1 contains a benzene ring, the benzene ring preferably has meta or para positions with the indolocarbazole ring and the pyrene ring, and more preferably has para positions with the indolocarbazole ring and the pyrene ring.

[0117] Ar2, Ar4 and Ar6

[0118] Ar2, Ar4, and Ar6 are each independently selected from the following groups: hydrogen atoms, deuterium atoms, aromatic hydrocarbon rings, and combinations of aromatic hydrocarbon rings. Aromatic hydrocarbon rings may have substituents.

[0119] Ar2, Ar4, and Ar6 can be aromatic hydrocarbon rings with 6 or more but less than 30 carbon atoms, aromatic hydrocarbon rings with 6 or more but less than 18 carbon atoms, or aromatic hydrocarbon rings with 6 or more but less than 15 carbon atoms. Specifically, Ar2, Ar4, and Ar6 can be benzene rings, naphthalene rings, spirofluorene rings, cyclopentadiene rings, triphenylene rings, or fluorene rings. Ar2, Ar4, and Ar6 can be benzene rings, or combinations of benzene rings and benzene rings (biphenyl).

[0120] When Ar2, Ar4, and Ar6 are aromatic hydrocarbon rings, the aromatic hydrocarbon rings may have substituents. Substituents may be deuterium atoms, substituted or unsubstituted alkyl groups having one or more but six or fewer carbon atoms, or substituted or unsubstituted aryl groups having six or more but eighteen or fewer carbon atoms. Specifically, substituents may be deuterium atoms, phenyl groups, phenyl groups having deuterium atoms, naphthyl groups, phenyl groups having tert-butyl groups, one or more methyl groups, one or more isopropyl groups, tert-butyl groups, tert-butyl groups having deuterium atoms, triphenylene groups, cyclohexyl groups, or phenyl groups having a CD3 group.

[0121] Ar2, Ar4, and Ar6 can be deuterium atoms, substituted or unsubstituted alkyl groups having one or more but four or fewer carbon atoms, or substituted or unsubstituted aryl groups having six or more but eighteen or fewer carbon atoms. Specifically, Ar2, Ar4, and Ar6 can be deuterium atoms, phenyl, naphthyl, phenyl groups having one or more but four or fewer carbon atoms, one or more methyl groups, tert-butyl groups having deuterium atoms, triphenylene groups, or triphenylene groups having phenyl groups.

[0122] Ar2, Ar4, and Ar6 can be deuterium atoms, substituted or unsubstituted alkyl groups having one or more but four or fewer carbon atoms, or substituted or unsubstituted aryl groups having six or more but eighteen or fewer carbon atoms. Specifically, Ar2, Ar4, and Ar6 can be deuterium atoms, phenyl groups, phenyl groups having a tert-butyl group, one or more methyl groups, or triphenylene groups.

[0123] Ar2, Ar4, and Ar6 can be deuterium atoms, substituted or unsubstituted alkyl groups having one or more but four carbon atoms, or phenyl groups having three or four carbon atoms. Specifically, Ar2, Ar4, and Ar6 can be deuterium atoms, one or more methyl groups, or phenyl groups having a tert-butyl group.

[0124] Ar2, Ar4, and Ar6 may not have substituents.

[0125] n, m and p

[0126] n, m, and p are 0 or 1, with n, m, and p preferably being 0. In other words, the indolocarbazole skeleton and the pyrene skeleton are preferably directly bonded to each other.

[0127] Specific examples of organic compounds according to this embodiment will be described below. However, this embodiment is not limited thereto.

[0128]

[0129]

[0130]

[0131] An exemplary compound belonging to Group A is one in which the entire molecule is composed of sp... 2 Compounds composed of carbon atoms. Therefore, among the organic compounds according to this embodiment, this compound is particularly an organic compound with excellent durability.

[0132] Exemplary compounds belonging to Group B are those in which Ar1, Ar3, and Ar5 have aromatic heterocycles. Therefore, charge transport properties are improved to provide organic light-emitting elements, particularly for low-voltage applications.

[0133] Exemplary compounds belonging to Group C are compounds having alkyl, silyl, or spirofluorene rings. Therefore, the organic compounds according to this embodiment are bulky and can reduce intermolecular stacking; thus, these compounds are particularly organic compounds with excellent luminescent efficiency.

[0134] (1-4) Organic compounds comprising an indole-carbazole skeleton in which a substituent is disposed at the meta position relative to the nitrogen atom.

[0135] The organic compound according to this embodiment is preferably an organic compound comprising an indole-carbazole skeleton, wherein a substituent is disposed at the meta position relative to the nitrogen atom of the indole-carbazole skeleton.

[0136] Due to this characteristic, the HOMO of the organic compound according to this embodiment becomes lower (further away from the vacuum energy level), resulting in superior durability of the organic compound. Among general formulas (1) to (3), the organic compound according to this embodiment is more preferably an organic compound represented by general formula (1).

[0137] Here, in a benzene ring with carbon-nitrogen bonds, the electron-donating ability at the meta position relative to the nitrogen atom is less than that at the para position. Therefore, when a substituent is placed at the meta position relative to the nitrogen atom, the HOMO becomes lower compared to the case where a substituent is placed at the para position. As a result, the organic compound according to this embodiment exhibits excellent oxidative stability and thus excellent durability.

[0138] Table 2 describes the HOMO of exemplary compound A9 as well as compounds 2-a and 2-b.

[0139] Table 2

[0140]

[0141] In Table 2, the HOMO of exemplary compound A9 is lower than that of compounds 2-a and 2-b. This is because exemplary compound A9 has a pyrene bonded in the meta position relative to the nitrogen atom of indolocarbazole, hence the low HOMO value.

[0142] Therefore, the organic compound according to this embodiment has a low HOMO, and thus is an organic compound with excellent oxidative stability. Therefore, organic light-emitting elements using the organic compound according to this embodiment have superior durability.

[0143] (1-5) The luminescent material emits fluorescence

[0144] The light-emitting material of the organic light-emitting element according to this embodiment is preferably a fluorescent compound.

[0145] The organic light-emitting element according to this embodiment has a structure in which triplet excitons in an organic compound are converted into singlet excitons and subsequently energy is efficiently transferred to the light-emitting material. Therefore, when the light-emitting material is a fluorescent compound, the generated excitons can be effectively used for luminescence, which is preferred from the viewpoint of luminescent efficiency.

[0146] Furthermore, fluorescence emission has a shorter emission lifetime than phosphorescence emission. Therefore, degradation of the emitting layer due to excitons can be reduced. As a result, the organic light-emitting element according to this embodiment also exhibits superior durability.

[0147] Note that the fluorescent materials refer to organic compounds and do not include organometallic complexes.

[0148] Specific examples of luminescent materials that can be used in organic light-emitting elements according to this embodiment will be described below.

[0149] However, this disclosure is not limited thereto.

[0150] The luminescent material of the organic light-emitting element according to this embodiment can be represented by general formula (4).

[0151]

[0152] In general formula (4), R 101 To R 112 Each is independently selected from the group consisting of: hydrogen atom, deuterium atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted heteroaryl group, substituted or unsubstituted heteroaryloxy group, substituted or unsubstituted amino group, and cyano group. 101 To R 112 They can be bonded together to form a ring.

[0153] R 101 To R 112 Each can be independently selected from the following groups: hydrogen atom, deuterium atom, substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, and cyano group. 101 To R 112 Each can be independently selected from the group consisting of: hydrogen atoms, deuterium atoms, substituted or unsubstituted alkyl groups having one or more but no more than six carbon atoms, substituted or unsubstituted aryl groups having six or more but no more than 18 carbon atoms, substituted or unsubstituted heteroaryl groups having five or more but no more than 12 carbon atoms, and cyano groups.

[0154] By making R 101 To R 112The ring formed by bonding together can be an aromatic hydrocarbon ring or an aromatic heterocycle, and is preferably an aromatic hydrocarbon ring. Specifically, when R 101 To R 112 When the luminescent material is bonded together to form a ring, the basic framework is preferably any one of FF7 to FF42, more preferably any one of FF7 to FF16, and even more preferably FF12 or FF14. Here, in organic compounds according to general formula (4), the basic framework refers to the one in which R 101 To R 112 All the R atoms that are not bonded together to form a ring are the backbone of hydrogen atoms.

[0155]

[0156]

[0157] The luminescent material of the organic light-emitting element according to this embodiment can be represented by any one of the general formulas (5) to (8).

[0158]

[0159] In general formulas (5) to (8), the cyclic units A to C are each independently selected from substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl. Q1 to Q3 are each independently selected from direct bonds, boron atoms, C(R) A (R) B ), N(R C ), oxygen atom, sulfur atom, selenium atom, or tellurium atom. R A To R C Each is independently selected from hydrogen atom, deuterium atom, halogen atom, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl. R C It can form a ring with adjacent ring units A to C.

[0160] The luminescent material of the organic light-emitting element according to this embodiment can be represented by general formula (9).

[0161]

[0162] In general formula (9), cyclic units A to E are each independently selected from substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl groups. Cyclic units A to E may be substituted or unsubstituted benzene skeletons. Optionally, cyclic units A, B, D, and E may be substituted or unsubstituted benzene skeletons, and cyclic unit C may be a substituted or unsubstituted benzene skeleton or a naphthalene skeleton. Q1 to Q3 are each independently selected from direct bonds, C(R) A (R) B ), N(RC ), B(R) D (Q1, Q4) can be direct bonds, consisting of oxygen, sulfur, selenium, or tellurium atoms. A To R D Each is independently selected from hydrogen atom, deuterium atom, halogen atom, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl.

[0163] (2) Other compounds

[0164] The organic light-emitting element according to this embodiment may include an organic compound layer other than the light-emitting layer constituting the organic light-emitting element. As needed, known low-molecular-weight or high-molecular-weight hole-injection or hole-transporting compounds, host compounds, light-emitting compounds, electron-injection compounds, or electron-transporting compounds may be additionally used. Examples of these compounds will be described below.

[0165] Such hole injection / transport materials are preferably materials with high hole mobility to facilitate hole injection from the anode and transport of the injected holes to the light-emitting layer. Furthermore, the material preferably has a high glass transition temperature to reduce film quality degradation, such as crystallization in organic light-emitting elements. Examples of low-molecular-weight or high-molecular-weight materials with hole injection / transport properties include triarylamine derivatives, arylcarbazole derivatives, phenylenediamine derivatives, stilbene derivatives, phthalocyanine derivatives, porphyrin derivatives, poly(vinylcarbazole), poly(thiophene), and other conductive polymers. The aforementioned hole injection / transport materials are also suitable for electron blocking layers. Specific examples of compounds used as hole injection / transport materials will be described below; however, this disclosure is certainly not limited thereto.

[0166]

[0167] Among the hole transport materials described above, HT16 to HT18 can reduce the driving voltage when used in the layer in contact with the anode. HT16 is widely used in organic light-emitting elements. In the organic compound layer adjacent to HT16, HT2, HT3, HT4, HT5, HT6, HT10, or HT12 can be used. Multiple materials can be used in a single organic compound layer.

[0168] Examples of luminescent materials that primarily contribute to luminescence include fused-ring compounds (e.g., fluorene derivatives, naphthalene derivatives, pyrene derivatives, perylene derivatives, tetraphenylene derivatives, anthracene derivatives, and rubrene), quinacridone derivatives, coumarin derivatives, stilbene derivatives, organoaluminum complexes such as tris(8-hydroxyquinoline)aluminum, iridium complexes, platinum complexes, rhenium complexes, copper complexes, europium complexes, ruthenium complexes, and polymeric derivatives such as poly(phenylenevinylene) derivatives, poly(fluorene) derivatives, and poly(phenylene) derivatives.

[0169] Specific examples of compounds used as luminescent materials will be described below; however, this disclosure is certainly not limited thereto.

[0170]

[0171]

[0172] The luminescent material is preferably a hydrocarbon compound because it can reduce the decrease in luminescence efficiency caused by the formation of exciplexes and the decrease in color purity caused by the change in the emission spectrum of the luminescent material due to the formation of exciplexes.

[0173] Hydrocarbon compounds are compounds consisting only of carbon and hydrogen; the above-mentioned exemplary compounds as hydrocarbon compounds are BD7, BD8, GD5 to GD9, and RD1.

[0174] The luminescent material is preferably a fused polycyclic compound containing a five-membered ring because it has a high ionization potential and is therefore less likely to be oxidized, thus providing a device with a high durability. Exemplary compounds belonging to this category are BD7, BD8, GD5 to GD9, and RD1.

[0175] Besides aromatic hydrocarbon compounds or their derivatives, examples of light-emitting layer host or light-emitting auxiliary materials included in the light-emitting layer include carbazole derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, organoaluminum complexes such as tris(8-quinolinolato)aluminum, and organobryllium complexes.

[0176] In the following, specific examples of compounds contained in the luminescent layer that serve as the host of the luminescent layer or as luminescent auxiliary materials will be described; however, this disclosure is certainly not limited thereto.

[0177]

[0178] The host material preferably comprises freely rotating single bonds as carbon-carbon bonds with high bond energy. The host material is preferably a hydrocarbon compound because the compounds disclosed herein more readily trap electrons and holes, resulting in a significant improvement in efficiency. The hydrocarbon compound is a compound consisting only of carbon and hydrogen; and the above-described exemplary compounds as hydrocarbon compounds are EM1 to EM12 and EM16 to EM27.

[0179] Electron transport materials can be appropriately selected from materials that transport electrons injected from the cathode to the light-emitting layer, taking into account, for example, a balance with the hole mobility of hole transport materials. Examples of materials with electron transport properties include oxadiazole derivatives, oxazole derivatives, pyrazine derivatives, triazole derivatives, triazine derivatives, quinoline derivatives, quinoxaline derivatives, phenanthroline derivatives, organoaluminum complexes, and fused-ring compounds (e.g., fluorene derivatives, naphthalene derivatives, thionyl derivatives, and anthracene derivatives). Such electron transport materials are also suitable for hole blocking layers.

[0180] Specific examples of compounds used as electron transport materials will be described below; however, this disclosure is certainly not limited thereto.

[0181]

[0182] Electron injection materials can be appropriately selected from those that readily inject electrons from the cathode, taking into account, for example, a balance with hole injection performance. Examples include organic compounds, such as n-type dopants and reducing dopants. Examples include alkali metal compounds such as lithium fluoride, lithium complexes such as lithium quinolinolate, benzoimidazolidene derivatives, imidazolidene derivatives, fulvalene derivatives, and acridine derivatives.

[0183] Electron injection materials can also be used in combination with the aforementioned electron delivery materials.

[0184] (3) Composition of organic light-emitting elements

[0185] The constituent components constituting the organic light-emitting element according to this embodiment will be described below.

[0186] An organic light-emitting element is formed on a substrate by creating an insulating layer, a first electrode, an organic compound layer, and a second electrode. A protective layer, a color filter, and a microlens can be disposed on the second electrode. When a color filter is disposed, a planarization layer can be placed between the protective layer and the color filter. The planarization layer can be formed from an acrylic resin or the like. This also applies when the planarization layer is disposed between the color filter and the microlens.

[0187] substrate

[0188] The substrate can be formed from quartz, glass, silicon wafer, resin, or metal. Switching elements such as transistors and wiring can be arranged on the substrate, and an insulating layer can be disposed thereon. The insulating layer can be formed from any material, as long as it allows for the formation of contact holes for wiring connection to the first electrode and ensures insulation from unconnected wiring. For example, resins such as polyimide, silicon oxide, or silicon nitride can be used.

[0189] electrode

[0190] As electrodes, a pair of electrodes can be used. A pair of electrodes refers to a first electrode and a second electrode. Specifically, a pair of electrodes can 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 the higher potential is the anode, and the other is the cathode. In other words, the electrode that supplies holes to the light-emitting layer is the anode, and the electrode that supplies electrons to the light-emitting layer is the cathode.

[0191] The anode is preferably formed of a material having the highest possible work function. Examples include elemental metals such as gold, platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium, and tungsten; mixtures thereof; alloys comprising the foregoing; and metal oxides such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide. Conductive polymers such as polyaniline, polypyrrole, and polythiophene can also be used.

[0192] These electrode materials can be used alone or in combination of two or more. The anode can be formed as a single layer or as multiple layers.

[0193] The reflective electrode can be formed from, for example, chromium, aluminum, silver, titanium, tungsten, molybdenum, the aforementioned alloys, or the aforementioned laminated structures. Such materials can also function as a reflective film that is not used as an electrode. Optionally, the transparent electrode can be formed as a transparent conductive oxide layer made of indium tin oxide (ITO) or indium zinc oxide, but the transparent electrode is not limited to these.

[0194] Electrodes can be formed using photolithography.

[0195] The cathode is preferably formed of a material with a low work function. Examples include alkali metals such as lithium, alkaline earth metals such as calcium, elemental metals such as aluminum, titanium, manganese, silver, lead, and chromium, and mixtures thereof. Alloys that are combinations of these elemental metals can also be used. Examples include magnesium-silver, aluminum-lithium, aluminum-magnesium, silver-copper, and zinc-silver. Metal oxides such as indium tin oxide (ITO) can also be used. Such electrode materials can be used alone or in combination of two or more of them. The cathode can be formed as a single layer or as multiple layers. In particular, silver is preferred; more preferably, silver alloys are used to reduce silver aggregation. There is no limitation on the alloy ratio as long as silver aggregation is reduced. For example, the ratio of silver to other metals can be 1:1 or 3:1.

[0196] There are no particular limitations on the cathode, and it can be formed as an oxide conductive layer such as ITO to provide a top emitting element, or as a reflective electrode such as aluminum (Al) to provide a bottom emitting element. There are no particular limitations on the method of forming the cathode; however, for example, DC or AC sputtering is preferred because such methods provide good film coverage and tend to provide lower resistance.

[0197] Organic compound layer

[0198] The organic compound layer can be formed as a single layer or as multiple layers. When multiple layers are arranged, they can be named according to their function as a hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, or electron injection layer. The organic compound layer is mainly formed of organic compounds, but may contain inorganic atoms or inorganic compounds, such as copper, lithium, magnesium, aluminum, iridium, platinum, molybdenum, or zinc. The organic compound layer can be arranged between the first electrode and the second electrode, and can be arranged in contact with the first electrode and the second electrode.

[0199] The organic compound layers (hole injection layer, hole transport layer, electron blocking layer, light-emitting layer, hole blocking layer, electron transport layer, and electron injection layer, etc.) constituting the organic light-emitting element according to this embodiment are formed by the following method.

[0200] The organic compound layer constituting the organic light-emitting element according to this embodiment can be formed using dry processes such as vacuum evaporation, ionization evaporation, sputtering, or plasma treatment. Alternatively, instead of dry processes, wet processes can be used, in which the material is dissolved in a suitable solvent and a known coating method (e.g., spin coating, dip coating, casting, LB coating, or inkjet coating) is used to form the layer.

[0201] Therefore, by forming the layer through methods such as vacuum evaporation or solution coating, crystallization is unlikely to occur, resulting in excellent stability over time. When forming the film using a coating method, an appropriate binder resin can be used additionally to form the film.

[0202] Examples of adhesive resins include, but are not limited to, polyvinylcarbazole resins, polycarbonate resins, polyester resins, ABS resins, acrylic resins, polyimide resins, phenolic resins, epoxy resins, silicone resins, and urea resins.

[0203] These adhesive resins can be used alone as homopolymers or copolymers, or as a mixture of two or more of them. Known additives, such as plasticizers, antioxidants, and UV absorbers, can be used as needed.

[0204] protective layer

[0205] A protective layer can be disposed on the cathode. For example, glass with a desiccant can be bonded to the cathode to reduce the penetration of water and the like into the organic compound layer, thereby reducing the occurrence of display defects. In another embodiment, a passivation film formed of silicon nitride or the like can be disposed on the cathode to reduce the penetration of water and the like into the organic compound layer. For example, after the cathode is formed, the substrate can be transferred to another chamber without breaking the vacuum, and a silicon nitride film with a thickness of 2 μm can be formed by CVD to serve as a protective layer. After the film is formed by CVD, the protective layer can also be formed by atomic layer deposition (ALD). There are no limitations on the material of the film formed by ALD, but it can be silicon nitride, silicon oxide, or aluminum oxide. A silicon nitride film can be further formed on the film formed by ALD by CVD. The ALD film can have a smaller film thickness than the CVD film. Specifically, the film thickness of the ALD film can be less than 50% or less than 10% of the film thickness of the CVD film.

[0206] Color filters

[0207] Color filters can be arranged on the protective layer. For example, a color filter corresponding to the size of the organic light-emitting element can be formed on another substrate and then bonded to the substrate on which the organic light-emitting element is formed; alternatively, the color filter can be formed by patterning the aforementioned protective layer using photolithography. The color filter can be formed from a polymer.

[0208] planarization layer

[0209] A planarization layer can be disposed between the color filter and the protective layer. The planarization layer is disposed to reduce the unevenness of the underlying layer. The planarization layer can be referred to as a material resin layer without limiting its purpose. The planarization layer can be formed from an organic compound, which can be a low-molecular-weight compound or a high-molecular-weight compound, and preferably a high-molecular-weight compound.

[0210] Such planarization layers can be arranged above and below the color filter and can be formed from the same or different materials. Specific examples include polyvinyl carbazole resin, polycarbonate resin, polyester resin, ABS resin, acrylic resin, polyimide resin, phenolic resin, epoxy resin, silicone resin, and urea resin.

[0211] microlenses

[0212] The organic light-emitting element according to this embodiment may include optical components such as microlenses on the light-emitting side. The microlenses may be formed from acrylic resins or epoxy resins. Microlenses may be arranged to increase the amount of light extracted from the organic light-emitting element or to control the direction of the extracted light. The microlenses may have a hemispherical shape. When the microlens has a hemispherical shape, there exists a tangent parallel to the insulating layer in the tangent line contacting the hemisphere, and the point of contact between this tangent line and the hemisphere is the vertex of the microlens. The vertex of the microlens can be similarly defined in any cross-sectional view. Specifically, in a cross-sectional view, there exists a tangent parallel to the insulating layer in the tangent line of the semicircle contacting the microlens, and the point of contact between this tangent line and the semicircle is the vertex of the microlens.

[0213] The midpoint of a microlens can also be defined. In the cross-section of a microlens, consider a line segment between the starting points of one arc and another arc; the midpoint of this line segment can be called the midpoint of the microlens. The cross-section used to determine the vertex and midpoint can be a cross-section perpendicular to the insulating layer.

[0214] Opposing substrate

[0215] The opposing substrate can be disposed on the planarization layer. The opposing substrate is disposed at a position corresponding to the aforementioned substrate, and is therefore called the opposing substrate. The opposing substrate can be formed of the same material as the aforementioned substrate. When the aforementioned substrate is referred to as the first substrate, the opposing substrate can be referred to as the second substrate.

[0216] Pixel circuit

[0217] The light-emitting device may include pixel circuitry connected to the light-emitting elements. The pixel circuitry may be an active matrix type that independently controls the light emission of a first light-emitting element and a second light-emitting element. The active matrix circuitry may be voltage-programmable or current-programmable. The driving circuitry has pixel circuitry for each pixel. The pixel circuitry may include the light-emitting element, a transistor for controlling the brightness of the light-emitting element, a transistor for controlling the timing of light emission, a capacitor for maintaining the gate voltage of the transistor controlling the brightness of light emission, and a transistor for connection to GND without passing through the light-emitting element.

[0218] The light-emitting device includes a display area and a peripheral area arranged around the display area. The display area has pixel circuitry, and the peripheral area has display control circuitry. The mobility of the transistors constituting the pixel circuitry may be less than the mobility of the transistors constituting the display control circuitry.

[0219] The slope of the current-voltage characteristic of the transistors constituting the pixel circuit can be less than the slope of the current-voltage characteristic of the transistors constituting the display control circuit. The slope of the current-voltage characteristic can be measured using the so-called Vg-Ig characteristic.

[0220] The transistors that make up the pixel circuit are transistors connected to light-emitting elements such as the first light-emitting element.

[0221] Pixels

[0222] An organic light-emitting device comprises multiple pixels. Each pixel includes sub-pixels that emit light of different colors from each other. For example, each sub-pixel may have an emission color of R, G, or B.

[0223] Each pixel has a region where light is emitted, also known as a pixel aperture. This region is the same as the first region.

[0224] The pixel aperture can have a size of less than 15μm or a size of more than 5μm. More specifically, for example, the size can be 11μm, 9.5μm, 7.4μm or 6.4μm.

[0225] The distance between subpixels can be less than 10μm, and specifically it can be 8μm, 7.4μm or 6.4μm.

[0226] In a planar graph, pixels can be arranged in a known manner. For example, pixels can be arranged in a stripe pattern, a delta pattern, a PenTile pattern, or a Bayer pattern. In a planar graph, subpixels can have any known shape. For example, the shape can be a quadrilateral such as a rectangle or rhombus, or a hexagon, etc. The term "rectangle" obviously covers shapes that are not exact rectangles but resemble rectangles. Such subpixel shapes and such pixel arrangements can be used in combination.

[0227] (4) Application of organic light-emitting elements according to this implementation scheme

[0228] The organic light-emitting element according to this embodiment can be used as a component of an image display device, a display device, or a lighting device. Other applications include: a display unit of an image display device comprising a display unit and a housing in which the display unit is disposed; an exposure light source of an electrophotographic image forming apparatus; a backlight of a liquid crystal display device; and a light-emitting device including a color filter for a white light source.

[0229] The display device may be an image information processing device, which includes an image input unit for inputting image information from an area CCD, a linear CCD, or a memory card, an information processing unit for processing the input information, and displays the input image on the display unit.

[0230] The display unit of a camera device or inkjet printer can have a touch panel function. There are no particular restrictions on the driving method for the touch panel function, and it can be an infrared method, a capacitive method, a resistive film method, or an electromagnetic induction method. The display device can be used as the display unit of a multifunction printer.

[0231] In the following description, the display device according to this embodiment will be described with reference to the accompanying drawings.

[0232] Figure 1A and Figure 1B This is a schematic cross-sectional view illustrating an example of a display device including an organic light-emitting element and a transistor connected to the organic light-emitting element. The transistor is an example of an active element. The transistor can be a thin-film transistor (TFT).

[0233] Figure 1A An example of a pixel as a constituent element of a display device according to this embodiment is shown. The pixel includes sub-pixels 10. Sub-pixels are classified as 10R, 10G, and 10B based on light emission. The emitted color can be distinguished based on the wavelength of light emitted from the light-emitting layer; alternatively, light emitted from such sub-pixels can be selectively transmitted or color-converted using a color filter or the like. Each sub-pixel includes a reflective electrode 2 serving as a first electrode, an insulating layer 3 covering the edge of the reflective electrode 2, an organic compound layer 4 covering the first electrode and the insulating layer, a transparent electrode 5, a protective layer 6, and a color filter 7 on the interlayer insulating layer 1.

[0234] The interlayer insulating layer 1 may be provided with transistors and capacitor elements disposed in or within it.

[0235] The transistor and the first electrode can be electrically connected via a contact hole or the like (not shown).

[0236] The insulating layer 3 is also called a bank or pixel separation film. The insulating layer 3 covers the edge of the first electrode and is arranged to surround the first electrode. The portion without the insulating layer is in contact with the organic compound layer 4 and serves as the light-emitting area.

[0237] The organic compound layer 4 has a hole injection layer 41, a hole transport layer 42, a first light-emitting layer 43, a second light-emitting layer 44, and an electron transport layer 45.

[0238] The second electrode 5 can be a transparent electrode, a reflective electrode, or a semi-transparent electrode.

[0239] Protective layer 6 reduces the penetration of moisture into the organic compound layer. The protective layer is shown as a single layer; however, the protective layer may include multiple layers. Each layer may include an inorganic compound layer and an organic compound layer.

[0240] Color filters 7 are categorized into 7R, 7G, and 7B based on color. Color filters can be formed on a planarization film (not shown). A resin protective layer (not shown) can be disposed on the color filters. Color filters can be formed on a protective layer 6. Optionally, color filters can be disposed on opposing substrates such as glass substrates and then bonded to other substrates.

[0241] Figure 1B A display device 100 is shown, which includes an organic light-emitting element 26 and a TFT 18, an example of a transistor. A substrate 11 is formed of glass or silicon, and an insulating layer 12 is disposed thereon. On the insulating layer, an active element 18, such as a TFT, is disposed, and a gate electrode 13, a gate insulating film 14, and a semiconductor layer 15 of the active element are disposed. The active element 18 further includes the semiconductor layer 15, a drain electrode 16, and a source electrode 17. An insulating film 19 is disposed on the active element 18. An anode 21 constituting the organic light-emitting element 26 is connected to the source electrode 17 via a contact hole 20 formed in the insulating film.

[0242] Note that the electrical connection scheme of the electrodes (anode and cathode) included in the organic light-emitting element 26 and the electrodes (source electrode and drain electrode) included in the TFT is not limited to... Figure 1B The example shown illustrates this. In other words, it is sufficient for either the anode or cathode to be electrically connected to either the TFT source electrode or the TFT drain electrode. TFT stands for Thin Film Transistor.

[0243] Figure 1B The display device 100 shown is a single-layer organic compound layer; however, the organic compound layer 22 may include multiple layers. A first protective layer 24 and a second protective layer 25 are disposed on the cathode 23 to reduce the degradation of the organic light-emitting element.

[0244] Figure 1B A display device 100 is shown that uses a transistor as a switching element; other switching elements may be used instead.

[0245] Figure 1B The transistors used in the display device 100 are not limited to transistors using monocrystalline silicon wafers, but can also be thin-film transistors having an active layer on an insulating surface of a substrate. The active layer can be formed of monocrystalline silicon, non-monocrystalline silicon such as amorphous silicon or microcrystalline silicon, or non-monocrystalline oxide semiconductors such as indium zinc oxide or indium gallium zinc oxide. Thin-film transistors are also known as TFT elements.

[0246] Figure 1BThe transistors included in the display device 100 can be formed in a substrate such as a Si substrate. The phrase "formed in a substrate" means that the transistors are manufactured by processing the substrate itself, such as a Si substrate. Such a structure in which the transistors are arranged in the substrate can also be considered as a structure in which the substrate and the transistors are formed as a single unit.

[0247] In the organic light-emitting element according to this embodiment, the luminous intensity is controlled by a TFT, which serves as an example of a switching element; and multiple such organic light-emitting elements are arranged on a surface, and their luminous intensity is used to display an image. Note that the switching element according to this embodiment is not limited to a TFT, but can also be a transistor formed of low-temperature polysilicon or an active matrix driver formed on a substrate such as a Si substrate. The phrase "on a substrate" encompasses "in a substrate." The choice between arranging transistors in the substrate or using TFTs depends on the size of the display unit; for example, when the size is about 0.5 inches, the organic light-emitting elements are preferably arranged on a Si substrate.

[0248] Figure 2 This is a schematic diagram illustrating an example of a display device according to this embodiment. The display device 1000 may include a touch panel 1003, a display panel 1005, a frame 1006, a circuit board 1007, and a battery 1008 disposed between an upper cover 1001 and a lower cover 1009. The display panel 1005 may include an organic light-emitting element according to this embodiment. The touch panel 1003 and the display panel 1005 respectively have flexible printed circuits (FPCs) 1002 and 1004 connected to them. Transistors are printed on the circuit board 1007. When the display device is not a portable device, the battery 1008 does not necessarily need to be disposed there; and even when the display device is a portable device, the battery 1008 can be disposed in other locations.

[0249] The display device according to this embodiment may include red, green, and blue color filters. The red, green, and blue color filters may be arranged in a delta array.

[0250] The display device according to this embodiment can be used as a display unit of a portable terminal. In this case, the display device can have both display and operation functions. Examples of portable terminals include mobile phones such as smartphones, tablet computers, and head-mounted displays.

[0251] The display device according to this embodiment can be used as a display unit of a camera device including an imaging element that receives light. The camera device may include a display unit that displays information acquired by the imaging element. The display unit may be an external display unit exposed to the camera device or a display unit arranged in a viewfinder. The camera device may be a digital camera or a digital video camera.

[0252] Figure 3A This is a schematic diagram illustrating an example of a camera device according to this embodiment. The camera device 1100 may include a viewfinder 1101, a rear display 1102, an operation unit 1103, and a housing 1104. The viewfinder 1101 and the rear display 1102 may include organic light-emitting elements according to this embodiment. In this case, the viewfinder 1101 and the rear display 1102 can display not only the image to be captured, but also environmental information and camera instructions, etc.

[0253] Environmental information can include the intensity and direction of external light, the speed at which an object moves, and the likelihood of an object being obscured by an occupant.

[0254] Since the timing for image capture is short, it is preferable to display the information as early as possible. Therefore, a display device using an organic light-emitting element according to this embodiment is preferred.

[0255] This is because organic light-emitting elements have a fast response speed.

[0256] The imaging device 1100 may further include an optical unit (not shown). The optical unit may include a single lens or multiple lenses; such lenses form an image on an imaging element housed in the housing 1104. The relative positions of the multiple lenses can be adjusted to adjust the focus. This operation can be performed automatically. The imaging device may also be referred to as a photoelectric conversion device. As an imaging method that captures images non-sequentially, the photoelectric conversion device may include methods for detecting differences from previous images and methods for cutting out images from continuously recorded images, etc.

[0257] Figure 3B This is a schematic diagram illustrating an example of an electronic device according to this embodiment. The electronic device 1200 includes a display unit 1201, an operation unit 1202, and a housing 1203. The housing 1203 may include circuitry, a printed circuit board including the circuitry, a battery, and a communication unit. The operation unit 1202 may include buttons or may include a touch-panel-based input unit. The operation unit may include a biometric identification unit that recognizes fingerprints and performs unlocking, etc. An electronic device including a communication unit may also be referred to as a communication device. The electronic device may include a lens and a camera element, thereby further having camera functionality. Images captured by the camera function are displayed on the display unit. Examples of electronic devices include smartphones and laptops.

[0258] Figure 4A and Figure 4B This is a schematic diagram illustrating an example of a display device according to this embodiment. Figure 4AA display device such as a television monitor or a PC monitor is shown. The display device 1300 includes a housing 1301 and a display unit 1302. The display unit 1302 may use an organic light-emitting element according to this embodiment.

[0259] The display device 1300 may include a support housing 1301 and a base 1303 for the display unit 1302. The base 1303 is not limited to... Figure 4A The lower side of the housing 1301 can also be used as a base.

[0260] The housing 1301 and the display unit 1302 can be curved and can have a radius of curvature of more than 5000 mm and less than 6000 mm.

[0261] Figure 4B This is a schematic diagram illustrating other examples of a display device according to this embodiment. Figure 4B In this embodiment, the display device 1310 can be foldable and is a so-called foldable display device. The display device 1310 includes a first display unit 1311, a second display unit 1312, a housing 1313, and a bending point 1314. The first display unit 1311 and the second display unit 1312 may include organic light-emitting elements according to this embodiment. The first display unit 1311 and the second display unit 1312 can constitute a single, seamless display device. The first display unit 1311 and the second display unit 1312 may be separated at the bending point. The first display unit 1311 and the second display unit 1312 can each display different images, or the first and second display units can together display a single image.

[0262] Figure 5A This is a schematic diagram illustrating an example of a lighting device according to this embodiment. The lighting device 1400 may include a housing 1401, a light source 1402, and a circuit board 1403. The light source 1402 may include an organic light-emitting element according to this embodiment. The lighting device 1400 may include an optical film 1404 to improve the color rendering index of the light source. The lighting device 1400 may also include a light diffusion unit 1405 to effectively diffuse the light from the light source. The lighting device 1400 including the light diffusion unit 1405 can transmit light over a wide range. The optical film 1404 and the light diffusion unit 1405 may be arranged on the light-emitting side of the lighting device. A cover may be arranged on the outermost side if necessary.

[0263] Lighting equipment is, for example, equipment for illuminating a room. Lighting equipment can emit light having any of the following colors: white, neutral white, and other colors from blue to red. The lighting equipment according to this embodiment may include a dimming circuit for dimming. The lighting equipment according to this embodiment may include a power supply circuit connected to the organic light-emitting element according to this embodiment. The power supply circuit may be a circuit that converts AC voltage to DC voltage. The term "white" corresponds to a color temperature of 4200K, and the term "neutral white" corresponds to a color temperature of 5000K. The lighting equipment according to this embodiment may further include a color filter.

[0264] The lighting device according to this embodiment may include a heat dissipation unit. The heat dissipation unit dissipates heat from the device to the outside of the device and may be formed of, for example, a metal or ceramic having high thermal conductivity.

[0265] Figure 5B This is a schematic diagram of an automobile, used as an example of a moving body according to this embodiment. The automobile includes taillights, which serve as an example of lighting devices. The automobile 1500 includes taillights 1501 and a body 1503, and can be configured to illuminate the taillights when braking is performed, etc. The body 1503 can also be referred to as a chassis. The automobile 1500 may include windows 1502 attached to the body 1503.

[0266] The taillight 1501 may include an organic light-emitting element according to this embodiment. The taillight may include a protective member to protect the light source. The protective member may be formed of any material, provided it has sufficient strength and is transparent, but is preferably formed of polycarbonate or the like. Polycarbonate may be mixed with furan dicarboxylic acid derivatives or acrylonitrile derivatives, etc.

[0267] When window 1502 is not used for inspecting the front and rear of a vehicle, it can be a transparent display. The transparent display may include an organic light-emitting element according to this embodiment.

[0268] In this case, the constituent materials, such as electrodes, included in the organic light-emitting element according to this disclosure are made of transparent components.

[0269] like Figure 5C As shown, the vehicle 1500 includes a handle 1504 for controlling the direction of movement of a moving body and a display unit 1505. The display unit 1505 displays, for example, a map, the position of the moving body, and the turning direction, and is mounted on the vehicle body 1503. The display unit 1505 may include an organic light-emitting element according to this embodiment.

[0270] The mobile body according to this embodiment includes one or both of a drive force generating unit that primarily generates driving force for the movement of the mobile body and a rotating body that primarily generates driving force for the movement of the mobile body. The drive force generating unit may be, for example, an engine or a motor. The rotating body may be, for example, a tire, a wheel, or a ship propeller. The mobile body may specifically be, for example, a bicycle, a car, a train, a ship, an aircraft, or a drone. The mobile body may include a body and a lighting device or a display unit arranged within the body. The lighting device may emit light to make the position of the body identifiable.

[0271] refer to Figure 6A and Figure 6B Examples of applications of the above-described display device according to the embodiments will be described. The display device can be applied to wearable systems such as smart glasses, head-mounted displays, and smart contact lenses. Display devices that can be used in wearable devices may include camera devices that perform photoelectric conversion of visible light and display devices that emit visible light.

[0272] Figure 6A and Figure 6B This is a schematic diagram illustrating an example of glasses (smart glasses) according to this embodiment. (Refer to...) Figure 6A The glasses 1600 (smart glasses) are described. The glasses 1600 includes a display unit on the rear surface side of a lens 1601. The display unit may include an organic light-emitting element according to this disclosure. Furthermore, a camera device 1602, such as a CMOS sensor or a SPAD, may be arranged on the front surface side of the lens 1601.

[0273] The glasses 1600 further include a controller 1603. The controller 1603 serves as a power source for supplying power to the camera device 1602 and the display unit. The controller 1603 also controls the operation of the camera device 1602 and the display unit. An optical system for collecting light from the camera device 1602 and the display unit is formed in the lens 1601.

[0274] refer to Figure 6BThe following describes glasses 1610 (smart glasses). Glasses 1610 includes a controller 1612, and the controller 1612 includes a display device including an organic light-emitting element according to the present disclosure. The controller 1612 may further include a camera device corresponding to a camera device 1602. An optical system for projecting light emitted from the controller 1612 is formed in a lens 1611, and an image is projected onto the lens 1611. The controller 1612 serves as a power source for supplying power to the camera device and the display device, and also controls the operation of the camera device and the display device. The controller may include a gaze detection unit for detecting the wearer's gaze. Gaze detection can be performed using infrared light. An infrared light emitting unit emits infrared light toward the eyeballs of a user gazing at the displayed image. In the emitted infrared light, a camera unit including a light receiving element detects reflected light from the eyeballs to obtain an image of the eyeballs. In the plan view, a light reduction unit that reduces the amount of light emitted from the infrared light emitting unit to the display unit reduces image quality degradation.

[0275] The controller 1612 detects the user's gaze toward the displayed image from an image of the eye captured by an infrared camera. Any known method can be applied for gaze detection using an image of the eye. An example could be a gaze detection method based on a Purkinje image generated by the reflection of incident light on the cornea.

[0276] More specifically, gaze detection processing based on the pupil-corneal reflex method is performed. The pupil-corneal reflex method is used to generate a gaze vector representing the direction (rotation angle) of the eyeball based on the pupil image included in the captured image of the eyeball and the Purkinje image, thereby detecting the user's gaze.

[0277] The display device according to this embodiment may include a camera device containing a light receiving element, and the display image of the display device may be controlled based on the gaze information of the user from the camera device.

[0278] Specifically, based on gaze information, the display device determines a first field of view area that the user is looking at and a second field of view area other than the first field of view area. The first and second field of view areas can be determined by the display device's controller, or the display device can receive areas determined by an external controller. Within the display area of ​​the display device, the display resolution of the first field of view area can be controlled to be higher than that of the second field of view area. In other words, the resolution of the second field of view area can be lower than that of the first field of view area.

[0279] The display area includes a first field of view and a second field of view, which is different from the first field of view. Based on viewing information, a higher-priority area is determined from the first and second field of view. The first and second field of view can be determined by the controller of the display device, or the display device can receive areas determined by an external controller. The resolution of the higher-priority area can be controlled to be higher than that of the lower-priority area. In other words, the resolution of the relatively lower-priority area can be reduced.

[0280] Note that AI can be used to determine a primary or high-priority visual field. AI can be a model configured to estimate the gaze angle and distance to the gaze target from an image of the eye, using images of the eye and the actual gaze direction within those images as training data. AI can be incorporated into a display device, a camera device, or an external device. When the external device includes AI, the display device is preferably applied to smart glasses that further include a camera for external imaging. The smart glasses can display the captured external information in real time.

[0281] Figure 7A This is a schematic diagram illustrating an example of an image forming apparatus according to this embodiment. The image forming apparatus 40 is an electrophotographic image forming apparatus, which includes a photoreceptor 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. The exposure light source 28 emits light 29 to form an electrostatic latent image on the surface of the photoreceptor 27. The exposure light source 28 may include an organic light-emitting element according to this embodiment. The developing unit 31 includes a toner, etc. The charging unit 30 charges the photoreceptor 27. The transfer unit 32 transfers the developed image onto a recording medium 34. The transport roller 33 transports the recording medium 34. For example, the recording medium 34 may be paper. The fixing unit 35 fixes the image formed on the recording medium 34.

[0282] Figure 7B and Figure 7C This is a schematic diagram showing the exposure light source 28, and illustrating the configuration in which a plurality of light-emitting elements 36 are arranged on a long substrate. Arrow 37 indicates the row direction of the organic light-emitting elements. This row direction is the same as the direction of the rotation axis of the photoreceptor 27. This direction can also be referred to as the long axis direction of the photoreceptor 27. Figure 7B The diagram shows the configuration in which the light-emitting portion 36 is arranged along the long axis of the photoreceptor 27. Figure 7C Showing with Figure 7BThe configurations differ, with the light-emitting portions 36 arranged alternately in the row direction in the first and second rows. The first and second rows are arranged at different positions in the column direction. In the first row, multiple light-emitting portions 36 are arranged at intervals. In the second row, light-emitting portions 36 are included at positions corresponding to the intervals between the light-emitting portions 36 in the first row. Therefore, multiple light-emitting portions 36 are also arranged at intervals in the column direction. Figure 7C The arrangement in the middle can also be called a grid arrangement, a staggered arrangement, or a checkerboard pattern.

[0283] As described above, devices using organic light-emitting elements according to this embodiment can provide stable display with excellent image quality even during long-term display.

[0284] Example

[0285] The present disclosure will be described below with reference to embodiments; however, the present disclosure is not limited thereto.

[0286] Examples 1 to 3 and Comparative Examples 1 to 2

[0287] In one embodiment, a blue bottom-emitting organic light-emitting element is manufactured 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 are sequentially formed on a substrate.

[0288] A 40 nm thick Ti film was deposited on a glass substrate by sputtering and then patterned using photolithography to form the anode. The anode was formed with a diameter of 3 mm. 2 The electrode area. The anode is then washed.

[0289] The substrate with the electrodes fabricated as described above was then mounted in a vacuum deposition apparatus (manufactured by ULVAC, Inc.). The vapor deposition material for deposition was prepared, and then a vacuum was applied to 1.33 × 10⁻⁶. -4 Pa (1×10 -6 (Torr). The interior of the chamber is then UV / ozone cleaned. A layer is then formed to provide the layer composition described in Table 3 below. The substrate is then transferred to a glove box and sealed with a glass lid containing a desiccant in a nitrogen atmosphere to obtain the organic light-emitting element. In the table, "%" represents "mass %".

[0290] In Examples 2 to 3 and Comparative Examples 1 to 2, organic light-emitting elements were manufactured in the same manner as in Example 1, except that the organic compound and the light-emitting material were changed to the materials described in Table 4.

[0291] Table 3

[0292]

[0293] The obtained components were measured and their characteristics evaluated. For each light-emitting element, at 100 mA / cm²... 2 The external quantum efficiency (EQE) was measured at a current density of 100 mA / cm². 2 A continuous drive test was conducted at a current density, and the time to a 5% decrease in brightness was measured. The results are described in Table 4. The device efficiency is expressed as a relative value by setting the EQE of Comparative Example 1 to 1.0, and the device durability is expressed as a ratio by setting the time to a 5% decrease in brightness in Comparative Example 1 to 1.0.

[0294] In this embodiment, the measuring instruments used are as follows: a microammeter 4140B manufactured by Hewlett-Packard Company is used to measure the current-voltage characteristics, and a BM7 manufactured by TOPCON CORPORATION is used to measure the luminous intensity.

[0295] Table 4

[0296]

[0297] Examples 4 to 6 and Comparative Example 3

[0298] The organic light-emitting element was manufactured in the same manner as in Example 1, except that the organic compound and the light-emitting material were changed to those described in Table 5. The results are described in Table 5. The element efficiency is expressed as a relative value by setting the EQE of Comparative Example 3 to 1.0, and the element durability is expressed as a ratio by setting the time to a 5% decrease in brightness in Comparative Example 3 to 1.0.

[0299] Table 5

[0300]

[0301] Examples 7 to 10 and Comparative Example 4

[0302] The organic light-emitting element was manufactured in the same manner as in Example 1, except that the organic compound and the light-emitting material were changed to those described in Table 6. The results are described in Table 6. The element efficiency is expressed as a relative value by setting the EQE of Comparative Example 4 to 1.0, and the element durability is expressed as a ratio by setting the time to a 5% decrease in brightness in Comparative Example 4 to 1.0.

[0303] Table 6

[0304]

[0305] Examples 11 to 14 and Comparative Examples 5 to 7

[0306] The organic light-emitting element was manufactured in the same manner as in Example 1, except that the organic compound and the light-emitting material were changed to those described in Table 7. The results are described in Table 7. The element efficiency was expressed as a relative value by setting the EQE of Comparative Example 6 to 1.0, and the element durability was expressed as a ratio by setting the time to a 5% decrease in brightness in Comparative Example 6 to 1.0.

[0307] Table 7

[0308]

[0309] Examples 15 to 17 and Comparative Examples 8 to 9

[0310] The organic light-emitting element was manufactured in the same manner as in Example 1, except that the organic compound and the light-emitting material were changed to those described in Table 8. The results are described in Table 8. The element efficiency is expressed as a relative value by setting the EQE of Comparative Example 8 to 1.0, and the element durability is expressed as a ratio by setting the time to a 5% decrease in brightness in Comparative Example 8 to 1.0.

[0311] Table 8

[0312]

[0313] Tables 5 through 8 have shown that the organic light-emitting elements according to the embodiments exhibit higher luminous efficiency than the organic light-emitting elements according to the comparative examples. This is presumably because such organic compounds and such light-emitting materials have similar permanent dipole moments, thereby providing improved compatibility between the organic compounds and the light-emitting materials, leading to more efficient energy transfer.

[0314] Table 5 compares Examples 4 and 5: the organic compound in Example 4 has a larger permanent dipole moment than the organic compound in Example 5; therefore, the organic light-emitting element in Example 4 exhibits higher luminous efficiency. Furthermore, Examples 5 and 6 are compared: the organic compound in Example 5 is a compound containing a pyrene framework with superior oxidation stability; therefore, Example 5 exhibits better element durability.

[0315] Table 6 compares Examples 7 and 8: the organic compound in Example 7 has a larger permanent dipole moment than the organic compound in Example 8; therefore, the organic light-emitting element in Example 7 exhibits higher luminous efficiency. Furthermore, Examples 8 and 9 are compared: the light-emitting material in Example 8 is a compound composed solely of hydrocarbons and exhibits excellent stability; therefore, the organic compound in Example 8 provides better element durability.

[0316] As described above, the organic light-emitting element according to this disclosure has excellent luminous efficiency. The organic light-emitting element according to this embodiment also exhibits excellent durability.

[0317] This disclosure provides an organic light-emitting element with excellent luminous efficiency.

[0318] Although this disclosure has been described with reference to embodiments, it should be understood that this disclosure is not limited to the disclosed embodiments. The scope of the appended claims should be given the broadest interpretation to cover all such modifications and equivalent structures and functions.

Claims

1. An organic light-emitting element, comprising: First electrode; Second electrode; and An organic compound layer disposed between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer comprising an organic compound and a luminescent material; the permanent dipole moment of the organic compound is defined as μ. h Furthermore, the permanent dipole moment of the luminescent material is defined as μ. d In this case, μ h / μ d It is above 0.6 and below 1.9; and The luminescent material is any one of formulas (4) to (9): ， In equation (4), R 101 To R 112 Each is independently selected from the group consisting of: hydrogen atom, deuterium atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted heteroaryl group, substituted or unsubstituted heteroaryloxy group, substituted or unsubstituted amino group, and cyano group; R 101 To R 112 They can be optionally bonded together to form a ring. In formulas (5) to (8), the cyclic units A to C are each independently selected from substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl; Q1 to Q3 are each independently selected from direct bonds, boron atoms, C(R A (R) B ), N(R C ), oxygen atom, sulfur atom, selenium atom, or tellurium atom; R A To R C Each is independently selected from hydrogen atom, deuterium atom, halogen atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryl group, or substituted or unsubstituted heteroaryl group; R C It can optionally form a ring with adjacent annular units A to C. In formula (9), cyclic units A to E are each independently selected from substituted or unsubstituted aryl or substituted or unsubstituted heteroaryl; cyclic units A to E are optionally substituted or unsubstituted benzene skeletons; cyclic units A, B, D and E are optionally substituted or unsubstituted benzene skeletons, and cyclic unit C is optionally substituted or unsubstituted benzene skeleton or naphthalene skeleton; Q1 to Q3 are each independently selected from direct bonds, C(R A (R) B ), N(R C ), B(R) D ), oxygen atom, sulfur atom, selenium atom, or tellurium atom; Q1 to Q4 are optionally direct bonds; and R A To R D Each is independently selected from hydrogen atom, deuterium atom, halogen atom, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted aryl, or substituted or unsubstituted heteroaryl.

2. The organic light-emitting element according to claim 1, wherein μ h / μ d It is above 0.6 and below 1.

8.

3. The organic light-emitting element according to claim 1, wherein μ h / μ d It is above 0.6 and below 1.

2.

4. The organic light-emitting element according to claim 1, wherein the organic compound comprises a fused polycyclic hydrocarbon ring having 10 or more but less than 30 carbon atoms.

5. The organic light-emitting element according to claim 1, wherein the organic compound comprises a fused polycyclic hydrocarbon ring having 3 or more but less than 6 rings.

6. The organic light-emitting element according to claim 1, wherein the organic compound comprises an anthracene skeleton, a phenanthrene skeleton, a fluorene skeleton, a pyrene skeleton, a triphenylene skeleton, a fluoranthene skeleton, a tetraphenylene skeleton, a β skeleton, a perylene skeleton, or a spirofluorene skeleton.

7. The organic light-emitting element according to claim 1, wherein the organic compound comprises a pyrene skeleton.

8. The organic light-emitting element according to claim 1, wherein the organic compound is any one of formulas (1) to (3): ， In equations (1) to (3), R1 to R 17 R 21 To R 38 and R 41 To R 58 Each is independently selected from the group consisting of: hydrogen atom, deuterium atom, substituted or unsubstituted alkyl group, substituted or unsubstituted alkoxy group, substituted or unsubstituted silyl group, substituted or unsubstituted amino group, and cyano group. Ar1, Ar3, and Ar5 are each independently selected from the group consisting of aromatic hydrocarbon rings, aromatic heterocycles, and combinations thereof; wherein the aromatic hydrocarbon rings optionally have substituents. Ar2, Ar4, and Ar6 are each independently selected from the group consisting of hydrogen atoms, deuterium atoms, aromatic hydrocarbon rings, and combinations of aromatic hydrocarbon rings; said aromatic hydrocarbon rings optionally have substituents, and n, m, and p are 0 or 1.

9. The organic light-emitting element according to claim 8, wherein the organic compound is an organic compound represented by formula (1).

10. The organic light-emitting element according to claim 8, wherein, In equations (1) to (3), n, m and p are 0.

11. The organic light-emitting element according to claim 1, wherein the organic compound comprises a rotatable single bond, and the rotatable single bond is a carbon-carbon bond.

12. The organic light-emitting element according to claim 1, wherein the light-emitting material is a fluorescent compound.

13. An organic light-emitting element, comprising: First electrode; Second electrode; and An organic compound layer disposed between the first electrode and the second electrode. The organic compound layer includes a light-emitting layer comprising an organic compound and a luminescent material; the permanent dipole moment of the organic compound is defined as μ. h Furthermore, the permanent dipole moment of the luminescent material is defined as μ. d In this case, μ h / μ d The concentration is above 0.6 and below 1.9, and the organic compound contains a pyrene skeleton.

14. A display device comprising a plurality of pixels, wherein at least one of the plurality of pixels comprises an organic light-emitting element according to any one of claims 1 to 13 and a transistor connected to the organic light-emitting element.

15. A photoelectric conversion device, comprising: An imaging element configured to receive light; and A display unit configured to display images captured by the camera element. The display unit includes an organic light-emitting element according to any one of claims 1 to 13.

16. An image display device, comprising: A display unit comprising an organic light-emitting element according to any one of claims 1 to 13; and The housing containing the display unit is located therein.

17. An electronic device comprising: A display unit comprising an organic light-emitting element according to any one of claims 1 to 13; The housing containing the display unit is located therein; and A communication unit arranged in the housing and configured to communicate with external units.

18. A wearable device comprising: A display unit comprising an organic light-emitting element according to any one of claims 1 to 13; An optical system configured to collect light from the display unit; and A controller configured to control the display of the display unit.

19. A lighting device comprising: A light source comprising an organic light-emitting element according to any one of claims 1 to 13; and The housing containing the light source is arranged therein.

20. A mobile body comprising: Lighting devices comprising organic light-emitting elements according to any one of claims 1 to 13; and The body in which the lighting device is arranged is a machine body.

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