Novel compounds and organic light-emitting elements comprising the same

Abstract

The present application provides a compound represented by the following Chemical Formula 1 and an organic light emitting element including the same: <Chemical Formula 1>

Description

Technical Field

[0001] This invention relates to a novel compound and an organic light-emitting element comprising the novel compound, and more particularly to a novel compound applicable to a capping layer and an organic light-emitting element comprising the novel compound. Background Technology

[0002] Materials used as organic layers in organic light-emitting elements can be broadly classified according to their function into light-emitting materials, hole injection materials, hole transport materials, electron transport materials, and electron injection materials.

[0003] Furthermore, the luminescent materials can be classified according to their luminescence mechanism into fluorescent materials originating from a singlet excited state of electrons and phosphorescent materials originating from a triplet excited state of electrons, and can also be classified according to their luminescence color into blue, green, and red luminescent materials.

[0004] A typical organic light-emitting device (OLED) can be structured with an anode formed on the top of a substrate, and a hole transport layer, a light-emitting layer, an electron transport layer, and a cathode sequentially formed on top of the anode. The hole transport layer, the light-emitting layer, and the electron transport layer are organic thin films composed of organic compounds.

[0005] The driving principle of the organic light-emitting element with the structure described above is as follows.

[0006] When a voltage is applied between the anode and cathode, holes injected from the anode will move to the light-emitting layer via the hole transport layer, while electrons injected from the cathode will move to the light-emitting layer via the electron transport layer. The holes and electrons will recombine in the light-emitting layer to generate excitons.

[0007] Light is generated during the transition of excitons from the excited state to the ground state. The efficiency of organic light-emitting elements can generally be divided into internal luminous efficiency and external luminous efficiency. Internal luminous efficiency is related to the efficiency of generating excitons and achieving light conversion in organic layers such as hole transport layers, light-emitting layers, and electron transport layers between the first and second electrodes. Theoretically, the internal luminous efficiency of fluorescence is 25%, while that of phosphorescence is 100%.

[0008] Furthermore, external luminous efficiency refers to the efficiency with which light generated in the organic layer is extracted to the outside of the organic light-emitting element. It is known that approximately 20% of the internal luminous efficiency can typically be extracted to the outside. As a method to improve the light extraction efficiency, to prevent the loss of light illuminating the outside due to total internal reflection, various organic compounds with a refractive index of 1.7 or higher are commonly used as a capping layer. Moreover, in order to improve the performance of organic light-emitting elements, efforts have been made to develop organic compounds with high refractive index and thin film stability that can improve external luminous efficiency. Summary of the Invention

[0009] Therefore, the purpose of this invention is to provide an organic light-emitting element that can improve the absorption wavelength in the ultraviolet region while ensuring a wide band gap in the region where visible light is difficult to absorb and maintaining a high refractive index, thereby achieving high color purity, high efficiency and long service life.

[0010] Furthermore, the present invention aims to provide an organic light-emitting element that can improve the thin film arrangement between molecules by increasing the polarizability of molecules and thereby improve the refractive index, and can also improve the stability to external air and / or moisture. Moreover, it can prevent recrystallization between molecules by using a higher glass transition temperature (Tg) and decomposition temperature (Td) and maintain the stability of the thin film when heat is generated during the device driving process, thereby further improving the external quantum efficiency and lifespan.

[0011] Next, we will provide a detailed explanation of the topics mentioned above, as well as any additional topics.

[0012] As a means of solving the problems mentioned above,

[0013] As an embodiment of the present invention, a compound represented by the following chemical formula 1 is provided:

[0014] <Chemical Formula 1>

[0015]

[0016] In the chemical formula 1,

[0017] X1 to X5 are each independently O, S, C, CR, N, Se, Te, NR, CRR', SiRR' or GeRR', and two or more of them are each O, S, N, Se, Te, NR, CRR', SiRR' or GeRR';

[0018] Ar1 to Ar3 are each independently a substituted or unsubstituted C6-C50 aryl group, or a substituted or unsubstituted C2-C50 heteroaryl group;

[0019] R and R' are each independently hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 mercapto, substituted or unsubstituted C3-C30 silyl, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl. R and R' may or may not form a ring by combining with each other.

[0020] L1 and L2 are each independently a directly bonded, substituted or unsubstituted C6-C50 arylene, or a substituted or unsubstituted C2-C50 heteroarylene.

[0021] Furthermore, as an embodiment of the present invention,

[0022] An organic light-emitting element comprising an organic layer containing the compound is provided.

[0023] The compound according to the invention is a compound containing a specific 5-membered ring and two amine groups as the parent nucleus, which can be used in capping layers. When used in capping layers, it can maintain a wide band gap in areas where visible light is difficult to absorb, thus exhibiting high color purity.

[0024] Furthermore, the compounds according to the present invention can be extended by substituents such as aryl or heteroaryl groups that are incorporated into specific 5-membered rings and amine groups, thereby increasing the absorption wavelength in the ultraviolet region while maintaining a high refractive index. Therefore, when applied to a capping layer, they can improve external quantum efficiency and have an excellent effect on improving ultraviolet stability.

[0025] In particular, because it contains a 5-membered ring with minimized volume characteristics and ensures excellent intermolecular film alignment by adding substituents such as aryl or heteroaryl groups bound to the amine group, it can not only improve the refractive index when used as a capping layer, but also significantly improve the stability to external air and / or moisture.

[0026] Furthermore, because the compounds according to the present invention have high glass transition temperature (Tg) and decomposition temperature (Td), they can prevent intermolecular recrystallization and maintain the stability of the film when heat is generated during device driving.

[0027] Next, we will explain in detail the effects described above and the additional effects. Attached Figure Description

[0028] Figure 1 This is a schematic cross-sectional view illustrating the structure of an organic light-emitting element according to an embodiment of the present invention.

[0029] Figure 2 This is a graph showing the absorption intensity of compounds 11 and 27, and comparative compounds 1 and 2, in the range of 340 nm to 460 nm according to an embodiment of the present invention.

[0030] [Symbol Explanation]

[0031] 100: Substrate

[0032] 200: Hole injection layer

[0033] 300: Hole Transport Layer

[0034] 400: Emissive layer

[0035] 500: Electron transport layer

[0036] 600: Electron Injection Layer

[0037] 1000: Electrode 1 (Anode)

[0038] 2000: Second electrode (cathode)

[0039] 3000: Overlay Detailed Implementation

[0040] Before providing a detailed description of the invention, it should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit the scope of the invention, which should be defined only by the scope of the appended claims. Unless otherwise expressly stated, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art.

[0041] Throughout this specification and the claims, unless otherwise expressly stated, the terms "comprise," "comprises," or "comprising" are used only to indicate that the mentioned object, step, or series of objects and steps are included, and do not preclude any other object, step, or series of objects or steps.

[0042] Throughout this specification and the claims, the term "aryl" may refer to substances including phenyl, benzyl, naphthyl, biphenyl, terphenyl, fluorene, phenanthrene, triphenylene, phenylene, etc. Benzyl, fluoranyl, benzo[a]fluorene, benzo[a]triphenylene, benzo[a] "Hyperaryl" refers to aromatic rings with C5-50 groups, including pyrrole, anthracene, piracene, and pyrene rings. "Heteroaryl" refers to groups containing pyrrole, pyrazinyl, pyridinyl, indole, isoindole, furanyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, benzothiophene, dibenzothiophene, quinolinyl, isoquinolinyl, quinoxalinyl, carbazolyl, phenanthridine, acridine, phenanthridine, thiophene, and those composed of pyridine, pyrazine, pyrimidine, pyridazine, triazine, indole, quinoline, acridine, pyrrolidine, and diphenyl rings. Alkyl ring, piperidine ring, morpholine ring, piperazine ring, carbazole ring, furan ring, thiophene ring, azole ring, A C2-50 aromatic ring containing one or more heterocyclic elements, consisting of a heterocyclic group composed of diazole ring, benzofuran ring, thiazole ring, thiadiazole ring, benzothiophene ring, triazole ring, imidazole ring, benzimidazole ring, pyran ring, dibenzofuran ring, etc.

[0043] In addition, Ar in the chemical formula x (where x is an integer) Unless otherwise explicitly defined, L represents a substituted or substituent C6-C50 aryl group, or a substituted or unsubstituted C2-C50 heteroaryl group, L x (where x is an integer) Unless otherwise explicitly defined, R represents a directly bonded, substituted or unsubstituted C6–C50 arylene, or a substituted or unsubstituted C2–C50 heteroarylene, R x (where x is an integer) Unless otherwise explicitly defined, it means hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 mercapto, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl.

[0044] Throughout this specification and the claims, the term "substituted or unsubstituted" means derived from deuterium, halogen, amino, cyano, nitrile, nitro, nitrosyl, aminosulfonyl, isothiocyanate, thiocyanate, carboxyl, or C1-C30 alkyl, C1-C30 alkylsulfinyl, C1-C30 alkylsulfonyl, C1-C30 alkylthioalkyl, C1-C12 fluoroalkyl, C2-C30 alkenyl, C1-C30 alkoxy, C1-C12 N The designation may include any one or more groups selected from the group consisting of alkylamino, C2-C20 N,N-dialkylamino, substituted or unsubstituted C1-C30 mercapto, C1-C6 N-alkylaminosulfonyl, C2-C12 N,N-dialkylaminosulfonyl, C3-C30 silyl, C3-C20 cycloalkyl, C3-C20 heterocycloalkyl, C6-C50 aryl, and C2-C50 heteroaryl, but is not specifically limited thereto. Furthermore, throughout this specification, unless otherwise expressly stated, the same symbols have the same meaning.

[0045] Furthermore, unless otherwise expressly stated to the contrary, various embodiments of the present invention may be combined with certain other embodiments. The embodiments of the present invention and their effects will now be described.

[0046] The present invention will now be described in detail.

[0047] The compounds according to the present invention can be represented by the following chemical formula 1:

[0048] <Chemical Formula 1>

[0049]

[0050] In the chemical formula 1,

[0051] X1 to X5 are each independently O, S, C, CR, N, Se, Te, NR, CRR', SiRR' or GeRR', and two or more of them are each O, S, N, Se, Te, NR, CRR', SiRR' or GeRR';

[0052] Ar1 to Ar3 are each independently a substituted or unsubstituted C6-C50 aryl group, or a substituted or unsubstituted C2-C50 heteroaryl group.

[0053] R and R' are each independently hydrogen, deuterium, halogen, nitro, nitrile, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted C2-C30 alkenyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted C1-C30 mercapto, substituted or unsubstituted C3-C30 silyl, substituted or unsubstituted C6-C50 aryl, or substituted or unsubstituted C2-C50 heteroaryl. R and R' may or may not form a ring by combining with each other.

[0054] L1 and L2 are each independently a directly bonded, substituted or unsubstituted C6-C50 arylene, or a substituted or unsubstituted C2-C50 heteroarylene.

[0055] Specifically, in the chemical formula 1, any one or more of X1 to X5 can be C or N, and in the case described above, the C or N can be combined with the linker L2.

[0056] The compound represented by the aforementioned chemical formula 1 is a compound whose core structure comprises two amino groups bonded to a specific 5-membered ring containing two or more heteroatoms or one or more heteroatoms and one or more CRR'. It is suitable for use as a capping layer and exhibits high color purity by maintaining a wide band gap in regions where visible light is difficult to absorb. Furthermore, it can enhance the absorption wavelength in the ultraviolet region while maintaining a high refractive index, and can improve the external quantum efficiency of organic light-emitting elements and enhance their stability against ultraviolet light.

[0057] Specifically, the chemical formula 1 can be represented by the following chemical formula 2 or chemical formula 3:

[0058] <Chemical Formula 2>

[0059]

[0060] <Chemical Formula 3>

[0061]

[0062] In chemical formulas 2 and 3,

[0063] For X1 to X5, Ar1 to Ar 3、 The definitions of L1 and L2 are the same as those in Chemical Formula 1 (wherein the number of carbons X1 to X5 bonded to L3 satisfies the range of carbon numbers defined in Ar1 or Ar2).

[0064] L3 is a directly bonded, substituted or unsubstituted C6-C50 arylene, or a substituted or unsubstituted C2-C50 heteroarylene.

[0065] The X1, X2, X3, X4, or X5 may be the same as or different from each other.

[0066] The compound represented by the chemical formula 2 or chemical formula 3 is a case in which one or more of Ar1 to Ar3 are substituted into a specific 5-membered ring by a linker L3. By including two or more specific 5-membered rings, a high refractive index can be achieved even with a smaller molecular weight.

[0067] Specifically, the compound represented by the chemical formula 2 has a structure in which Ar3 is substituted to a specific 5-membered ring via a linker L3. By employing a structure in which two specific 5-membered rings are respectively substituted to two amine groups, the absorption in the visible light region can be minimized while the light absorption in the ultraviolet region is enhanced.

[0068] Furthermore, the compound represented by the aforementioned chemical formula 3 is a case where Ar1 is substituted to a specific 5-membered ring via a linker L3. By employing a structure in which two specific 5-membered rings are simultaneously substituted to either amine group, the volume characteristics of one side of the amine group can be minimized, thereby improving the refractive index more effectively.

[0069] More specifically, the chemical formula 1 can be represented by the following chemical formula 4 or chemical formula 5:

[0070] <Chemical Formula 4>

[0071]

[0072] <Chemical Formula 5>

[0073]

[0074] In chemical formulas 4 and 5,

[0075] The definitions of X1 to X5 and Ar1 to Ar3 are the same as those in Formula 1 (wherein, the number of carbons in X1 to X5 bound to the amine via m repeating units satisfies the range of carbon numbers defined in Ar1 or Ar2).

[0076] L1 is a substituted or unsubstituted C6-C30 aryl group, or a substituted or unsubstituted C2-C30 heteroaryl group;

[0077] l and m are each an independent integer from 1 to 3.

[0078] The X1, X2, X3, X4, or X5 may be the same as or different from each other.

[0079] Compounds represented by Chemical Formula 4 or Chemical Formula 5 have a structure in which two or more specific 5-membered rings are substituted into a core containing two amino groups, and the specific 5-membered rings are substituted by linkers containing one or more phenylene groups. As described above, the volume characteristics of the linker can be minimized by introducing phenylene groups, thereby achieving the effect of minimizing unwanted absorption in long wavelength regions while maintaining a high refractive index.

[0080] Specifically, the compound represented by the chemical formula 4, by employing a structure in which two specific 5-membered rings are linked to an amino group through one or more phenylene groups and respectively substituted to two amino groups, can minimize the volume characteristics of the linker and thereby enhance light absorption in the ultraviolet region while minimizing absorption in the visible light region.

[0081] Furthermore, the compound represented by the aforementioned chemical formula 5, by employing a structure in which two specific 5-membered rings are bonded to an amino group via one or more phenylene groups and simultaneously substituted to any one of the amino groups, can minimize the volume characteristics of one side of the amino group and thereby more effectively improve the refractive index.

[0082] Furthermore, in any one of the chemical formulas 1 to 5,

[0083] A specific 5-membered ring, i.e. It may include any of the structures represented by A-1 to A-36 below, specifically any of A-1 to A-15. In the case described above, by minimizing the volumetric characteristics of the core, absorption in the visible light region can be minimized while maintaining a high refractive index. Furthermore, the deposition temperature can be effectively improved, especially when any of A-8 to A-15 is included, which can significantly improve the refractive index.

[0084]

[0085] In structures A-1 to A-36,

[0086] R1 to R3 are each independently hydrogen, deuterium, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C6-C30 aryl, or substituted or unsubstituted C4-C20 heteroaryl.

[0087] * indicates the binding position.

[0088] Specifically, R1 to R3 can each be hydrogen; methyl; ethyl; isopropyl; methyl or fluorinated or unsubstituted phenyl; naphthyl; biphenyl; or pyridyl. In the case described above, the volume characteristics of a specific 5-membered ring can be minimized, thereby further improving the refractive index.

[0089] More specifically, one or more of R1 to R3 can be phenyl, and as described above, the volume characteristics of a specific 5-membered ring can be further minimized, thereby further improving the refractive index of the compound.

[0090] In any of the chemical formulas 1 to 5, it can be achieved by using The specific 5-membered ring structure minimizes the volume characteristics of the compound, and a wider band gap in the region where visible light is difficult to absorb can be maintained by adopting a specific 5-membered ring structure containing more than 2 heteroatoms or more than 1 heteroatom and more than 1 CRR', thereby exhibiting high color purity.

[0091] Specifically, because It contains two or more heteroatoms, specifically one or two or more N atoms. Therefore, the refractive index can be increased by further improving the polarizability of the compound, and the intensity of absorption of ultraviolet light can also be increased.

[0092] Furthermore, in any one of the chemical formulas 1 to 5,

[0093] The L1 to L3 can each be independently phenylene, biphenylene, triphenylene, naphthylene, fluorene, spirodifluorene, pyridyl, or a combination thereof, which, as described above, can more effectively improve the refractive index of the compound.

[0094] Specifically, L2 and L3 can each independently contain one or more phenylene, biphenylene, or triphenylene, etc. More specifically, they can be phenylene, and even more specifically, they can be p-phenylene (1,4-phenylene). Under the above-described conditions, the deposition temperature can be effectively improved while maintaining a high refractive index.

[0095] Furthermore, L1 may include any of the structures represented by B-1 to B-13 below:

[0096]

[0097] When L1 is any one of B-1 to B-13 as described above, a high refractive index can be achieved by linearly linking the two amine atoms. Specifically, L1 can be either B-2 or B-3.

[0098] Furthermore, B-1 to B-7 may contain ortho (1,2-phenylene), meta (1,3-phenylene), or para (1,4-phenylene) combinations, specifically para (1,4-phenylene), or more specifically, para (1,4-phenylene) alone.

[0099] Furthermore, in any one of the chemical formulas 1 to 5,

[0100] Ar1 to Ar3 may each independently comprise any one of the structures represented by the following structures C-1 to C-16:

[0101]

[0102] In structures C-1 to C-16,

[0103] X6 and X7 are each independently CH or N, and more than one of them is N.

[0104] X8 to X 11 Each is independently C, CR4R5, N, NR4, O, or S, and more than one of them is O, S, or N.

[0105] R4 and R5 are each independently hydrogen, halogen, nitrile, substituted or unsubstituted C1-C10 alkyl, substituted or unsubstituted C1-C10 alkoxy, substituted or unsubstituted C1-C10 mercapto, substituted or unsubstituted C1-C20 aryl, or substituted or unsubstituted C1-C20 heteroaryl.

[0106] Specifically, in the chemical formulas 1 to 5, Ar1 to Ar3 can each independently be structure C-1, C-2, C-4 or C-6. With the substituents as described above, the substituent volume characteristics of the compound can be minimized, thus ensuring excellent intermolecular film arrangement, achieving high refractive index and enhancing absorption in the ultraviolet region.

[0107] The following compounds are specific examples of compounds according to the present invention. These examples are merely illustrative of the invention and are not intended to limit the invention.

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142] One embodiment of the compound of the present invention can be synthesized by an amination reaction, the general synthetic reaction formula of which is shown below.

[0143]

[0144] In another embodiment of the invention, an organic light-emitting element is provided comprising an organic layer containing the compound according to the invention as described above, wherein the organic layer may specifically be a capping layer.

[0145] The organic light-emitting element according to the present invention will now be described in more detail.

[0146] In one embodiment of the present invention, the organic light-emitting element may include a first electrode, a second electrode, and one or more organic layers between the first electrode and the second electrode, and may also include a covering layer that can be disposed outside any one or more of the first electrode and the second electrode.

[0147] Specifically, the side of the first or second electrode adjacent to the organic layer between the first and second electrodes is called the inner side, and the side not adjacent to the organic layer is called the outer side. That is, when the capping layer is disposed on the outer side of the first electrode, the first electrode will be located between the capping layer and the organic layer, and when the capping layer is disposed on the outer side of the second electrode, the second electrode will be located between the capping layer and the organic layer.

[0148] Furthermore, in one embodiment of the present invention, the inner sides of the first electrode and the second electrode of the organic light-emitting element may be interposed with one or more layers of various organic materials, while a capping layer may be formed on the outer side of either the first electrode or the second electrode. That is, the capping layer may be formed simultaneously on the outer side of the first electrode and the outer side of the second electrode, or it may be formed only on the outer side of the first electrode or the outer side of the second electrode.

[0149] At this time, the covering layer may contain compounds according to the invention, may contain only compounds according to the invention, or may contain two or more known compounds simultaneously.

[0150] Furthermore, the refractive index of the coating layer at a wavelength of 450nm can be 2.20 or higher, specifically 2.25 or higher, more specifically 2.30 or higher, and the ultraviolet absorption intensity at a wavelength of 380nm can be 0.7 or higher, specifically 0.8 or higher or 0.9 or higher.

[0151] Furthermore, the organic layer may include a hole transport layer, a light-emitting layer, and an electron transport layer that typically constitute the light-emitting part, but is not limited to these.

[0152] Specifically, according to one embodiment of the present invention, an organic light-emitting element may include one or more organic layers constituting light-emitting portions such as a hole injection layer (HIL), a hole transport layer (HTL), a light-emitting layer (EML), an electron transport layer (ETL), and an electron injection layer (EIL) between the first electrode (anode) and the second electrode (cathode).

[0153] Figure 1 This is a cross-sectional view illustrating the structure of an organic light-emitting element according to an embodiment of the present invention. An organic light-emitting element according to one embodiment of the present invention can be configured as follows... Figure 1 The structure shown is manufactured.

[0154] like Figure 1 As shown, the organic light-emitting element can be a structure in which a substrate 100, a first electrode 1000, a hole injection layer 200, a hole transport layer 300, a light-emitting layer 400, an electron transport layer 500, an electron injection layer 600, a second electrode 2000, and a capping layer 3000 are stacked sequentially from bottom to top.

[0155] The substrate 100 can be a substrate commonly used in organic light-emitting elements, especially a transparent glass substrate or a flexible plastic substrate with excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of processing and water resistance.

[0156] Furthermore, the first electrode 1000 is used as a hole injection electrode for injecting holes into an organic light-emitting element. To achieve hole injection, the first electrode 1000 is manufactured using a material with the lowest possible work function, and can be formed using transparent materials such as indium tin oxide (ITO), indium zinc oxide (IZO), and graphene.

[0157] Meanwhile, the hole injection layer 200 can be formed by depositing the hole injection layer material on the upper part of the first electrode 1000 using methods such as vacuum deposition, spin coating, casting, or the Langmuir-Blodgett method. When forming the hole injection layer 200 by vacuum deposition, the deposition conditions will vary depending on the compound used as the material of the hole injection layer 200, the desired structure of the hole injection layer 200, and its thermal properties. Typically, deposition temperatures of 50–500°C and 10… -8 Up to 10 -3 The vacuum level of the Torr is 0.01 to... deposition rate per second and The layer thickness should be appropriately selected within the range of up to 5 μm. Furthermore, a charge generation layer can be deposited on the surface of the hole injection layer 200 as needed. Common materials can be used as the charge generation layer material, such as hexacyano-hexaazabenzophenanthrene (HATCN).

[0158] Furthermore, the hole transport layer 300 can be formed by depositing hole transport layer material on top of the hole injection layer 200 using methods such as vacuum deposition, spin coating, casting, or the Langmuir-Brønder (LB) method. When forming the hole transport layer 300 by the vacuum deposition method, the deposition conditions will vary depending on the compound used, but it is generally preferable to select conditions within a range almost identical to those for forming the hole injection layer 200. The hole transport layer 300 can be formed using known compounds. The hole transport layer 300 described above can be one or more layers, and although... Figure 1 Although not illustrated, a light-emitting auxiliary layer can be added above the hole transport layer 300.

[0159] Simultaneously, the light-emitting layer 400 can be formed by depositing a light-emitting layer material on top of the hole transport layer 300 or the light-emitting auxiliary layer using methods such as vacuum deposition, spin coating, casting, or the Langmuir-Brønder (LB) method. When forming the light-emitting layer 400 by vacuum deposition, the deposition conditions will vary depending on the compound used, but are generally preferably selected within a range of conditions almost identical to those for forming the hole injection layer 200. Known compounds can be used as the light-emitting layer material, either as the main agent or dopant.

[0160] When phosphorescent dopants are used simultaneously in the light-emitting layer material, to prevent triplet excitons or holes from diffusing into the electron transport layer 500, a stacked hole-blocking material (HBL) can be added to the upper part of the light-emitting layer 400 using vacuum deposition or spin coating. The hole-blocking material used is not particularly limited; any known material can be used. For example, it can be... Diazole derivatives or benzotriazole derivatives, o-diazaphenanthroline derivatives, or hole-blocking materials described in Japanese Patent Application Publication No. 11-329734 (A1), among which the most representative include Balq (bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum), phenanthroline compounds (e.g., UDC's BCP), etc. The light-emitting layer 400 of the present invention, as described above, may comprise one or more blue light-emitting layers.

[0161] Furthermore, the electron transport layer 500 is formed on top of the light-emitting layer 400 and can be formed by methods such as vacuum deposition, spin coating, or casting. The deposition conditions of the electron transport layer 500 will vary depending on the compound used, but are generally preferably selected within the same range as those for the formation of the hole injection layer 200.

[0162] Furthermore, the electron injection layer 600 can be formed by depositing electron injection layer material on the upper part of the electron transport layer 500, and can be formed by methods such as vacuum deposition, spin coating, casting, etc.

[0163] Meanwhile, the second electrode 2000 serves as an electron injection electrode and can be formed on the upper part of the electron injection layer 600 by methods such as vacuum deposition or spin coating. Various metals can be used as the material for the second electrode 2000. Specific examples include substances such as aluminum, gold, silver, and magnesium, but it is not limited to these.

[0164] The organic light-emitting element of the present invention can not only use the organic light-emitting element containing the capping layer 3000, the first electrode 1000, the hole injection layer 200, the hole transport layer 300, the light-emitting layer 400, the electron transport layer 500, the electron injection layer 600, the second electrode 2000 and the capping layer 3000 as described above, but can also use organic light-emitting elements with various structures, and can also add an intermediate layer containing one or two layers as needed.

[0165] Furthermore, the thickness of each organic layer formed by the present invention can be adjusted according to the desired degree, specifically from 10 to 1000 nm, and more specifically from 20 to 150 nm.

[0166] The covering layer 3000, as Figure 1 As shown, the hole injection layer 200 may be formed on the outer side of the first electrode 1000 where no hole injection layer 200 is formed. Similarly, the electron injection layer 600 may be formed on the outer side of the second electrode 2000 where no electron injection layer 600 is formed, but this is not a limitation. The capping layer 3000 described above can be formed by a deposition process, and the thickness of the capping layer 3000 can be 100 mm to... More specifically, it could be 300 to By adjusting the thickness as described above, the problem of reduced transmittance of the cover layer 3000 can be prevented.

[0167] In addition, although Figure 1 Although not illustrated, according to one embodiment of the present invention, an organic layer for performing various functions may be additionally formed between the cover layer 3000 and the first electrode 1000 or between the cover layer 3000 and the second electrode 2000. Alternatively, an organic layer for performing various functions may also be additionally formed on the upper part (outer surface) of the cover layer 3000, but this is not a limitation.

[0168] Next, the present invention will be described in more detail through examples of the synthesis of compounds according to an embodiment of the present invention and examples of the manufacture of organic light-emitting elements. The following synthesis examples and embodiments are merely illustrative of the present invention, and the scope of the present invention is not limited to the following examples.

[0169] <Synthetic Example 1> Synthesis of Compound 11

[0170]

[0171] Pour 80 ml of toluene into a round-bottom flask and dissolve 2.0 g of 2-(4-bromophenyl)-5-phenyl-1,3,4- The reaction mixture was refluxed with stirring after adding 2.2 g of N4,N4'-diphenyl-[1,1'-biphenyl]-4,4'-diamine, 1.0 g of t-BuONa, 0.2 g of Pd2(dba)3, and 0.3 mL of (t-Bu)3P. The extent of the reaction was confirmed by thin-layer chromatography (TLC), and the reaction was terminated after the addition of water. The organic layer was extracted with dichloromethane (MC), purified by column chromatography under reduced pressure, and recrystallized to obtain 3.5 g of compound 11 (68% yield).

[0172] m / z: 776.29 (100.0%), 777.29 (58.5%), 778.30 (15.8%), 779.30 (3.1%), 778.29 (1.7%)

[0173] <Synthetic Example 2> Synthesis of Compound 27

[0174]

[0175] Compound 27 was synthesized in 63% yield by substituting N4,N4”-diphenyl-[1,1':4',1”-terphenyl]-4,4”-diamine (N4,N4”-diphenyl-[1,1':4',1”-terphenyl]-4,4”-diamine) for N4,N4'-diphenyl-[1,1'-biphenyl]-4,4’-diamine.

[0176] m / z: 852.32 (100.0%), 853.32 (64.9%), 854.33 (20.1%), 855.33 (4.7%), 854.32 (1.4%)

[0177] <Synthetic Example 3> Synthesis of Compound 39

[0178]

[0179] The same procedure as in Synthesis Example 1 was followed, wherein compound 39 was synthesized by replacing N4,N4'-diphenyl-[1,1'-biphenyl]-4,4'-diamine with N4,N4-diphenyl-[1,1'-biphenyl]-4,4'-diamine (N4,N4-diphenyl-[1,1'-biphenyl]-4,4'-diamine) (yield 60%).

[0180] m / z: 776.29 (100.0%), 777.29 (58.5%), 778.30 (15.8%), 779.30 (3.1%), 778.29 (1.7%)

[0181] <Synthetic Example 4> Synthesis of Compound 49

[0182]

[0183] The procedure was carried out in the same manner as in Synthesis Example 1, wherein 5-(4-bromophenyl)-3-phenyl-1,2,4- Diazole (5-(4-bromophenyl)-3-phenyl-1,2,4-oxadiazole) replaces 2-(4-bromophenyl)-5-phenyl-1,3,4-oxadiazole Compound 49 was synthesized from diazole (2-(4-bromophenyl)-5-phenyl-1,3,4-oxadiazole) in a yield of 66%.

[0184] m / z: 776.29 (100.0%), 777.29 (58.5%), 778.30 (15.8%), 779.30 (3.1%), 778.29 (1.7%)

[0185] <Synthetic Example 5> Synthesis of Compound 62

[0186]

[0187] The procedure was carried out in the same manner as in Synthesis Example 1, wherein 5-(4-bromophenyl)-2-phenyl 5-(4-bromophenyl)-2-phenyloxazole replaces 2-(4-bromophenyl)-5-phenyl-1,3,4- Compound 62 was synthesized from diazole (2-(4-bromophenyl)-5-phenyl-1,3,4-oxadiazole) in a yield of 61%.

[0188] m / z: 774.30 (100.0%), 775.30 (60.0%), 776.31 (17.0%), 777.31 (3.5%), 776.30 (1.3%)

[0189] <Synthetic Example 6> Synthesis of Compound 97

[0190]

[0191] The procedure was carried out in the same manner as in Synthesis Example 1, except that 2-(4-bromophenyl)-5-phenyl-1,3,4-thiadiazole and N1,N4-diphenylbenzene-1,4-diamine were used instead of 2-(4-bromophenyl)-5-phenyl-1,3,4-thiadiazole. Compound 97 was synthesized from diazole (2-(4-bromophenyl)-5-phenyl-1,3,4-oxadiazole) and N4,N4'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (N4,N4'-diphenyl-[1,1'-biphenyl]-4,4'-diamine) in 63% yield.

[0192] m / z: 732.2130 (100.0%), 733.2163 (49.8%), 734.2197 (12.1%), 734.2088 (9.0%), 735.2121 (4 .5%), 733.2100 (2.2%), 735.2231 (1.9%), 733.2124 (1.6%), 734.2134 (1.1%), 736.2155 (1.1%)

[0193] <Synthetic Example 7> Synthesis of Compound 102

[0194]

[0195] The procedure was carried out in the same manner as in Synthetic Example 1, except that 2-(4-bromophenyl)-5-phenyl-1,3,4-thiadiazole was used instead of 2-(4-bromophenyl)-5-phenyl-1,3,4-thiadiazole. Compound 102 was synthesized from diazole (2-(4-bromophenyl)-5-phenyl-1,3,4-oxadiazole) in 60% yield.

[0196] m / z: 808.2443 (100.0%), 809.2476 (56.2%), 810.2510 (15.5%), 810.2401 (9.0%), 811.2434 (5 .1%), 811.2544 (2.8%), 809.2413 (2.2%), 809.2437 (1.6%), 812.2468 (1.4%), 810.2447 (1.2%)

[0197] <Synthetic Example 8> Synthesis of Compound 106

[0198]

[0199] The procedure was performed in the same manner as in Synthetic Example 1, except that 2-(4-bromophenyl)-5-phenyl-1,3,4-thiadiazole and N1,N1-diphenylbenzene-1,4-diamine were used instead of 2-(4-bromophenyl)-5-phenyl-1,3,4-thiadiazole. Compound 106 was synthesized from diazole (2-(4-bromophenyl)-5-phenyl-1,3,4-oxadiazole) and N4,N4'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (N4,N4'-diphenyl-[1,1'-biphenyl]-4,4'-diamine) in 60% yield.

[0200] m / z: 732.2130 (100.0%), 733.2163 (49.8%), 734.2197 (12.1%), 734.2088 (9.0%), 735.2121 (4 .5%), 733.2100 (2.2%), 735.2231 (1.9%), 733.2124 (1.6%), 734.2134 (1.1%), 736.2155 (1.1%)

[0201] Manufacturing of organic light-emitting elements

[0202] Figure 1 This is a schematic diagram illustrating the structure of a typical organic light-emitting element, used as an example of the present invention. Figure 1 Based on the illustrated organic light-emitting element structure, a charge generation layer (not shown) is added between the hole injection layer 200 and the hole transport layer 300, and an electron injection layer (not shown) is added between the electron transport layer 500 and the cathode 2000. Specifically, the manufactured organic light-emitting element is formed by stacking the following layers from bottom to top in the following order: anode (hole injection electrode 1000) / hole injection layer 200 / charge generation layer (not shown) / hole transport layer 300 / light-emitting layer 400 / electron transport layer 500 / electron injection layer 600 / cathode (electron injection electrode 2000) / capping layer 3000.

[0203] When manufacturing organic light-emitting elements, the substrate 10 can be a transparent glass substrate or a flexible plastic substrate.

[0204] The hole injection electrode 1000 is used as an anode for injecting holes in an organic light-emitting element. To achieve hole injection, a material with the lowest possible work function is used, and transparent materials such as indium tin oxide (ITO), indium zinc oxide (IZO), and graphene can be used to form it.

[0205] The materials shown in Table 1 below are used in the hole injection layer 200, charge generation layer, hole transport layer 300, light emission layer 400, electron transport layer 500, and electron injection layer 600.

[0206] Furthermore, a cathode 2000 for injecting electrons is formed on the upper side of the electron injection layer 600. Various metals can be used as the cathode. Specific examples include materials such as aluminum, gold, and silver.

[0207] Table 1

[0208]

[0209] <Example 1>

[0210] An indium tin oxide (ITO) substrate with a silver (Ag) reflective layer was cleaned using ultrasonic waves with distilled water. After washing with distilled water, ultrasonic cleaning was performed using solvents such as isopropanol, acetone, and methanol, followed by drying. Next, a hole injection layer was formed on the ITO substrate using a thermal evaporator. HI01, as a charge generation layer HATCN and its role as a hole transport layer Next, in the BH01 body, dopant BD01 is doped at 3% by weight to form a film. The light-emitting layer is then formed. Next, a film is prepared using a mixture of ET01 and Liq (1:1, wt. / wt.). The electron transport layer is then formed using LiF deposition. After an electron injection layer of a certain thickness, a 15 nm cathode is formed by MgAg deposition, and then a capping layer is deposited on top of the cathode to form... The thickness of the compound was obtained by synthesis example 1. An organic light-emitting element was fabricated by encapsulating the element in a glove box.

[0211] Example 2 to Example 5

[0212] Organic light-emitting elements were manufactured by means of the same method as in Example 1, and organic light-emitting elements were manufactured by depositing a capping layer using the compounds produced by Synthesis Examples 2 to 5.

[0213] Comparative Examples 1 to 3

[0214] Organic light-emitting elements were fabricated by depositing capping layers using comparative compounds 1 to 3 as shown in Table 2 below, in accordance with the same method as in Example 1.

[0215] Table 2

[0216]

[0217] <Experimental Example 1> Performance Evaluation of Organic Light-Emitting Components

[0218] By injecting electrons and holes by applying a voltage to a Kiethley 2400 source measurement unit and measuring the brightness of the emitted light using a Konica Minolta spectroradiometer (CS-2000), the performance of the organic light-emitting elements of Examples 1 to 5 and Comparative Examples 1 to 3 was evaluated under atmospheric pressure conditions, namely, the current density and brightness relative to the applied voltage. The results are shown in Table 3.

[0219] Table 3

[0220] Example 1 3.55 10 7.72 0.139 0.045 160 Example 2 3.55 10 7.76 0.140 0.044 167 Example 3 3.54 10 7.74 0.140 0.045 161 Example 4 3.55 10 7.71 0.140 0.044 158 Example 5 3.55 10 7.66 0.140 0.046 153 Comparative Example 1 3.57 10 6.95 0.131 0.053 105 Comparative Example 2 3.56 10 6.70 0.130 0.056 82 Comparative Example 3 3.56 10 7.04 0.134 0.051 90

[0221] By comparing the embodiments of the present invention, it can be found that the organic light-emitting elements of the embodiments can achieve a lower driving voltage, and their luminous efficiency and lifespan are also significantly improved.

[0222] Specifically, referring to Table 3, the organic light-emitting element of the embodiment utilizes a compound that achieves high molecular polarizability and glass transition temperature (Tg) by including a specific 5-membered ring and two amine groups to form a capping layer. As a result, the refractive index of the capping layer can be increased, and the absorption wavelength in the ultraviolet region can be enhanced, while also stably forming a thin film. In particular, the compound can be composed of compounds such as... azole, The organic light-emitting elements of the embodiments containing specific heterocyclic 5-membered rings such as diazole minimize the volume characteristics of the molecule. Therefore, compared with the organic light-emitting elements of Comparative Examples 1 to 3, the organic light-emitting elements of the embodiments containing such rings in the capping layer have higher color purity and better effects on improving the efficiency and lifespan of the elements.

[0223] <Experimental Example 2> Refractive Index Assessment

[0224] Using the compounds of Synthesis Example 1 (Compound 11), Synthesis Example 2 (Compound 27), and Synthesis Example 3 (Compound 39) according to the present invention, and the compounds of Comparative Examples 1 to 3 in Table 2, a deposition film with a thickness of 30 nm was fabricated on a silicon substrate using a vacuum deposition apparatus. The refractive index at 450 nm was then measured using an ellipsometry (JAWoollam Co. Inc., M-2000X). The results are shown in Table 4 below.

[0225] Table 4

[0226]

[0227] As shown in Table 4, it can be confirmed that the compound according to the present invention exhibits a refractive index of 2.2 or higher, specifically 2.25 or higher, at a wavelength of 450 nm. As described above, because the compound according to the present invention can exhibit a high refractive index, it can be used as a capping layer to achieve organic light-emitting elements with significantly improved external quantum efficiency and lifespan.

[0228] <Experimental Example 3> Evaluation of Ultraviolet Absorption Intensity

[0229] Using Synthesis Example 1 (Compound 11) and Synthesis Example 2 (Compound 27) according to the present invention, and Comparative Compound 1 and Comparative Compound 2 in Table 2, a 30 nm thick deposition film was fabricated on a silicon substrate using a vacuum deposition apparatus. The absorption wavelength in the range of 340 nm to 460 nm was then measured using an ellipsometer (JAWoollam Co. Inc., M-2000X). The results are as follows: Figure 2 As shown.

[0230] like Figure 2 As shown, it can be confirmed that the compound according to the present invention has an absorption intensity of 0.8 or higher, specifically 0.9 or higher, in the ultraviolet region at a wavelength of 380 nm. Compared with the comparative compound and the compound of comparative compound 2, its absorption intensity is increased by more than 60%, specifically more than 80%. As described above, the compound according to the present invention exhibits an enhanced absorption wavelength in the ultraviolet region, and therefore, when applied to a capping layer, it can realize an organic light-emitting element with high color purity, high efficiency, and long lifespan.

Claims

1. An organic light-emitting element comprising: an organic layer, said organic layer containing a compound of chemical formula 2 or 3 or... or The compound is represented, and the organic layer is a capping layer: Chemical formula 2 Chemical formula 3 In the chemical formulas 2 and 3, Ar1 and Ar2 are each independently a halogenated, nitrile, C1 alkyl, C1 alkoxy, or C1 thioether-substituted phenyl group, or any of the structures represented by C-1 to C-5 and C-11 below. Ar3 is any one of the structures represented by the following structures C-1 to C-5 and C-11. L1 can be phenylene, biphenylene, terphenylene, naphthylene, fluorene, or spirodifluorene. L2 and L3 are each independently a direct-linked, phenylene, biphenylene, terphenylene, naphthylene, fluorenyl, spirodifluorenyl, or pyridyl group. For any of the structures represented by A-1 to A-5, A-8 to A-13, A-35 and A-36 below: In structures A-1 to A-5, A-8 to A-13, A-35, and A-36, R1 is independently hydrogen; deuterium; methyl; ethyl; isopropyl; methyl or fluoro-substituted or unsubstituted phenyl; naphthyl; biphenyl; or pyridyl. * indicates the location of the union. In structures C-1 to C-5 and C-11, R4 and R5 are each independently hydrogen, halogen, nitrile, C1 alkyl, C1 alkoxy, C1 thioether or phenyl.

2. The organic light-emitting element according to claim 1, The chemical formula 2 or 3 refers to compounds represented by the following chemical formula 4 or chemical formula 5: Chemical Formula 4 Chemical formula 5 In chemical formulas 4 and 5, L1 and The definition is the same as that in chemical formula 2 or 3. Ar1 to Ar3 are each independently any one of the structures represented by C-1 to C-5 and C-11. l and m are each an independent integer from 1 to 3.

3. The organic light-emitting element according to claim 1, It is any one of the structures represented by structures A-1 to A-5 and A-8 to A-13.

4. The organic light-emitting element according to claim 1, L2 to L3 are each independently phenylene, biphenylene, terphenylene, naphthylene, fluorene, spirodifluorene, or pyridyl.

5. The organic light-emitting element according to claim 1, L1 to L3 each independently contain 1,4-phenylene.

6. The organic light-emitting element according to claim 1, Ar1 to Ar3 are each independently the structure C-1, C-2 or C-4.

7. The organic light-emitting element according to claim 1, The compound of chemical formula 2 or 3 is any one of the compounds represented by the following chemical formulas: 。 8. The organic light-emitting element according to claim 1, The organic light-emitting element comprises: Electrode 1; The second electrode; and, One or more organic layers are located inside the first electrode and the second electrode; The covering layer is disposed on the outside of any one or more of the first electrode and the second electrode.

9. The organic light-emitting element according to claim 1, characterized in that: The coating layer has a refractive index of 2.20 or higher at a wavelength of 450 nm.

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