Compound for capping layer and organic electroluminescent divice including the same

Abstract

The present invention relates to a compound for a capping layer and an organic light-emitting device including the same. A compound for a capping layer according to one embodiment of the present invention can be applied to an organic light-emitting device to improve the external luminous efficiency, color coordinates, and lifespan of the organic light-emitting device.

Description

Technology Field

[0001] The present invention relates to a novel compound for a capping layer and an organic light-emitting device comprising the same. Background Technology

[0003] Generally, an organic light-emitting diode refers to a device that converts electrical energy into light energy using organic materials. An organic light-emitting diode can generally have a structure in which an anode is formed on a substrate, and a hole transport layer, an emissive layer, an electron transport layer, and a cathode are sequentially formed on the anode.

[0005] When a voltage is applied between the anode and the cathode of an organic light-emitting diode, holes are injected from the anode and move to the light-emitting layer via a hole transport layer, and at the same time, electrons are injected from the cathode and move to the light-emitting layer via an electron transport layer. The holes and electrons moved to the light-emitting layer recombine to generate excitons. As the excitons change from an excited state to a ground state, light is generated.

[0007] The efficiency of an organic light-emitting diode can generally be divided into internal luminescence efficiency and external luminescence efficiency. Internal luminescence efficiency is related to how efficiently excitons are generated and converted into light in organic layers formed between the first and second electrodes, such as the hole transport layer, the emissive layer, and the electron transport layer. Theoretically, internal luminescence efficiency is known to be about 25% for fluorescence and about 100% for phosphorescence.

[0008] Meanwhile, external luminescence efficiency represents the efficiency of light generated in the organic layer formed between the first and second electrodes being extracted to the outside of the organic light-emitting device, and it is generally known that it is extracted to the outside at a level of about 20% of the internal luminescence efficiency.

[0009] To increase external luminescence efficiency, or light extraction, various organic compounds have been applied as capping layers to prevent light loss due to total internal reflection. Furthermore, continuous efforts have been made to develop organic compounds with high refractive indices and thin-film stability capable of enhancing external luminescence efficiency to improve the performance of organic light-emitting devices. Prior art literature

[0011] Korean Published Patent 10-2004-0098238 The problem to be solved

[0012] The present invention provides an organic light-emitting device comprising a novel compound for a capping layer and a capping layer containing said compound for a capping layer.

[0013] However, the problems that this invention seeks to solve are not limited to those described above, and other problems not described will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0015] One aspect of the present invention is to provide a compound for a capping layer represented by the following chemical formula 1.

[0016] [Chemical Formula 1]

[0017]

[0019] In the above chemical formula 1,

[0020] Ar, Ar1 to Ar3 are each independently substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 2~50 It is a heteroaryl group of, and

[0021] L is a substituted or unsubstituted C 6~50 The arylene group of, or substituted or unsubstituted C 2~50 It is a heteroarylene group,

[0022] R1 is hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group of, or substituted or unsubstituted C 1~30 It is a sulfide group of, and

[0023] l is an integer from 1 to 6.

[0024] Another aspect of the present invention provides an organic light-emitting device comprising: first and second electrodes; an organic layer interposed between the first and second electrodes; and a capping layer disposed outside at least one of the first and second electrodes and containing a compound for a capping layer according to the present invention. Effects of the invention

[0026] A compound for a capping layer according to one embodiment of the present invention can improve the color purity of an organic light-emitting device by maintaining a wide bandgap that cannot absorb wavelengths in the RGB region of the organic light-emitting device.

[0027] In addition, the compound for the capping layer according to one embodiment of the present invention has naphthalene having an aryl or heteroaryl substituent directly bonded to nitrogen, so that phyconjugation is increased and the molecular arrangement can be excellent, and accordingly, when forming a thin film, the packing density is increased and a high refractive index is maintained, thereby increasing the external quantum efficiency.

[0028] In addition, naphthalene having aryl or heteroaryl substituents is directly bonded to nitrogen, resulting in a broad absorption wavelength in the ultraviolet region. Furthermore, the formation of a stable thin film improves stability against exposure to air, moisture, and ultraviolet rays, thereby enabling the realization of long-life organic light-emitting devices.

[0029] In addition, since diarylamine has a naphthalene having an aryl or heteroaryl substituent, it can have a high Tg, which can suppress intermolecular recrystallization and provide stability against heat generated during operation. Brief explanation of the drawing

[0031] FIG. 1 is a schematic diagram of an organic light-emitting device according to one embodiment of the present invention. Figure 2 is a graph showing the results of evaluating the ultraviolet absorption intensity of a deposited film prepared using a compound for a capping layer according to one embodiment of the present invention and a compound of Ref. 1. Specific details for implementing the invention

[0032] Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention.

[0033] However, the present invention may be implemented in various different forms and is not limited to the embodiments and examples described herein. Furthermore, in order to clearly explain the invention in the drawings, parts unrelated to the description have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0034] Throughout this specification, when a component is described as being located "on" another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0035] Throughout this specification, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Throughout this specification, terms of degree such as "about," "substantially," etc., are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the stated meaning, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure in which precise or absolute values ​​are mentioned to aid in understanding this specification. Throughout this specification, terms of degree such as "a step of" or "a step of" do not mean "a step for."

[0036] Throughout this specification, the term “combination thereof” included in the Markush-type expression means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-type expression, and means including one or more selected from the group consisting of said components.

[0037] Throughout this specification, the description of "A and / or B" means "A or B, or A and B".

[0038] Throughout this specification, the term "aryl" refers to C 5-50 It means comprising an aromatic hydrocarbon ring group, for example, phenyl, benzyl, naphthyl, biphenyl, terphenyl, fluorene, phenanthrenyl, triphenylenyl, perylenyl, crisenyl, fluoranthenyl, benzofluorenyl, benzotriphenylenyl, benzocrisenyl, anthracenyl, stilbenyl, pyrenyl, etc., and "heteroaryl" means C containing at least one heteroatom. 3-50 As an aromatic ring, for example, pyrrolyl, pyrazinyl, pyridinyl, indolyl, isoindolyl, furyl, benzofuranyl, isobenzofuranyl, dibenzofuranyl, benzothiophenyl, dibenzothiophenyl, quinolyl group, isoquinolyl, quinoxalinyl, carbazolyl, phenanthridinyl, acridinyl, phenanthrolinyl, thienyl, and pyridine ring, pyrazine ring, pyrimidine ring, pyridazine ring, triazine ring, indole ring, quinoline ring, acridine ring, pyrrolidine ring, dioxane ring, piperidine ring, morpholine ring, piperazine ring, carbazole ring, furan ring, thiophene ring, oxazole ring, oxadiazole ring, benzoxazole ring, thiazole ring, thiadiazole ring, benzothiazole ring, triazole ring, imidazole It may mean that it includes a heterocyclic ring formed from a ring, a benzimidazole ring, a pyran ring, and a dibenzofuran ring.

[0039] Throughout this specification, the term "substituted or non-substituted" refers to deuterium, halogen, amino group, nitrile group, nitro group, or C1-C 30 alkyl group of, C2~C 30 alkenyl group of, C1~C 30 alkoxy groups, C3~C 20 cycloalkyl group of, C3~C 20 heterocycloalkyl group of, C6~C 30 aryl group and C3~C 30 It may mean that it is substituted or not substituted with one or more groups selected from the group consisting of heteroaryl groups. Additionally, throughout this specification, the same symbols may have the same meaning unless specifically stated otherwise.

[0041] One aspect of the present invention relates to a compound for a capping layer represented by the following chemical formula 1.

[0042] [Chemical Formula 1]

[0043]

[0044] In the above chemical formula 1,

[0045] Ar, Ar1 to Ar3 are each independently substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 2~50 It is a heteroaryl group of, and

[0046] L is a substituted or unsubstituted C 6~50 The arylene group of, or substituted or unsubstituted C 2~50 It is a heteroarylene group,

[0047] R1 is hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group of, or substituted or unsubstituted C 1~30 It is a sulfide group of, and

[0048] l is an integer from 1 to 6.

[0049] The compound for the capping layer of Formula 1 according to one embodiment of the present invention can improve the color purity of the organic light-emitting device by maintaining a wide bandgap that cannot absorb wavelengths in the RGB region of the organic light-emitting device.

[0050] In addition, the compound for the capping layer according to one embodiment of the present invention has naphthalene having an aryl or heteroaryl substituent directly bonded to nitrogen, so that phyconjugation is increased and the molecular arrangement can be excellent, and accordingly, when forming a thin film, the packing density is increased and a high refractive index is maintained, thereby increasing the external quantum efficiency.

[0051] In addition, naphthalene having aryl or heteroaryl substituents is directly bonded to nitrogen, resulting in a broad absorption wavelength in the ultraviolet region. Furthermore, the formation of a stable thin film improves stability against exposure to air, moisture, and ultraviolet rays, thereby enabling the realization of long-life organic light-emitting devices.

[0052] In addition, since diarylamine has a naphthalene having an aryl or heteroaryl substituent, it can have a high Tg, which can suppress intermolecular recrystallization and provide stability against heat generated during operation.

[0054] In one embodiment of the present invention, the formula 1 may be represented by the following formula 2 or formula 3.

[0055] [Chemical Formula 2]

[0056]

[0058] [Chemical Formula 3]

[0059]

[0061] In the above Chemical Formula 2 or Chemical Formula 3,

[0062] Ar' is independently substituted or unsubstituted C 6~40 The aryl group of, or substituted or unsubstituted C 2~40 It is a heteroaryl group of, and

[0063] m is an integer from 1 to 7.

[0064] The compound represented by the above chemical formula 2 or chemical formula 3 has high Tg and Td, which can contribute to increasing the driving stability of the device.

[0066] In one embodiment of the present invention, L in formulas 1 to 3 may be selected from the group consisting of phenylene, biphenylene, terphenylene, naphthylene, phenanthrenylene, fluorenylene, and combinations thereof. In this case, it may be effective in maintaining a wide band gap.

[0068] In addition, in one embodiment of the present invention, the formula 1 may be represented by any one of the following formulas 4 to 6.

[0069] [Chemical Formula 4]

[0070]

[0072] [Chemical Formula 5]

[0073]

[0075] [Chemical Formula 6]

[0076]

[0078] In the above chemical formulas 4 to 6,

[0079] X is O, S, NAr4, or CRR', and

[0080] The above Ar4 is hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group of,

[0081] L1 and L2 are each independently directly bonded, substituted, or unsubstituted C 6~38 The arylene group of, or substituted or unsubstituted C 2~38 It is a heteroarylene group, and

[0082] R and R' are each independently hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group, and adjacent R and R' may or may not form a ring, and

[0083] Ar' is independently substituted or unsubstituted C 6~40 The aryl group of, or substituted or unsubstituted C 2~40 It is a heteroaryl group of, and

[0084] m is an integer from 1 to 7, and n is an integer from 0 or 1 to 4.

[0086] Compounds represented by the above chemical formulas 4 to 6 may be more effective in blocking absorption in the visible light region.

[0088] In addition, in one embodiment of the present invention, the formula 1 may be represented by any one of the following formulas 7 to 9.

[0089] [Chemical Formula 7]

[0090]

[0091] [Chemical Formula 8]

[0092]

[0093] [Chemical Formula 9]

[0094]

[0096] In the above chemical formulas 7 to 9,

[0097] X is O, S, NAr4, or CRR', and

[0098] The above Ar4 is hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group of,

[0099] R and R' are each independently hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group, and adjacent R and R' may or may not form a ring, and

[0100] Ar' is a substituted or unsubstituted C 6~40 The aryl group of, or substituted or unsubstituted C 2~40 It is a heteroaryl group of, and

[0101] Ar2' is a substituted C 6~50 The aryl group of, substituted or unsubstituted C 10~50 The aryl group of, or substituted or unsubstituted C 2~50 It is a heteroaryl group.

[0102] Compounds represented by the above chemical formulas 7 to 9 may be more effective in improving the refractive index.

[0104] In addition, in one embodiment of the present invention, the formula 1 may be represented by any one of the following formulas 10 to 12.

[0105] [Chemical Formula 10]

[0106]

[0107] [Chemical Formula 11]

[0108]

[0109] [Chemical Formula 12]

[0110]

[0112] In the above chemical formulas 10 to 12,

[0113] X is O, S, NAr4, or CRR', and

[0114] The above Ar4 is hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group of,

[0115] R and R' are each independently hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group, and adjacent R and R' may or may not form a ring, and

[0116] Ar' is a substituted or unsubstituted C 6~40 The aryl group of, or substituted or unsubstituted C 2~40 It is a heteroaryl group of, and

[0117] Ar2' is a substituted C 6~50 The aryl group of, substituted or unsubstituted C 10~50 The aryl group of, or substituted or unsubstituted C 2~50 It is a heteroaryl group.

[0118] The compounds represented by the above chemical formulas 10 to 12 have a broad absorption band of 300 nm to 400 nm, which can be more effective in improving the stability of the device from UV exposure.

[0120] In one embodiment of the present invention, in the formulas 1 to 12, Ar, Ar1 to Ar4, and Ar' are each independently selected from the group consisting of phenyl, naphthyl, biphenyl, terphenyl, pyridinyl, and combinations thereof, and Ar2' can be selected from the group consisting of toluenyl, naphthyl, biphenyl, terphenyl, pyridinyl, and combinations thereof. In this case, a wide band gap can be provided and the refractive index can be further improved at the same time.

[0122] In one embodiment of the present invention, in Formulas 1 to 12, Ar, Ar1 to Ar4, Ar' and Ar2' may each independently have one or more substituents selected from the group consisting of alkyl groups, alkoxy groups, sulfide groups, halogens, cyano groups, and combinations thereof. In this case, an amorphous thin film can be formed, thereby further improving stability against exposure to air and moisture from the outside.

[0124] In one embodiment of the present invention, the compound for the capping layer may be any one of the following compounds, but is not limited thereto.

[0125] .

[0126] delete

[0127] delete

[0128] delete

[0129] delete

[0130] delete

[0131] delete

[0132] delete

[0133] delete

[0134] delete

[0135] delete

[0136] delete

[0137] delete

[0139] In one embodiment of the present invention, the compounds for the capping layer represented by Chemical Formulas 1 to 12 can be synthesized by the following Reaction Formulas 1 to 3, but are not limited thereto and can also be synthesized by various methods.

[0140] [Reaction Equation 1]

[0141]

[0142] [Reaction Equation 2]

[0143]

[0144] [Reaction Equation 3]

[0145]

[0146] In the above reaction formulas 1 to 3, Ar, Ar1 to Ar3, R1, L, and l are as defined in the above chemical formula 1, and h represents a halogen atom.

[0148] Another aspect of the present invention is to provide an organic light-emitting device having a capping layer comprising a compound for a capping layer according to the present invention.

[0149] According to one embodiment of the present invention, an organic light-emitting device may comprise: a first and a second electrode; an organic layer interposed between the first and second electrodes; and a capping layer disposed on the outer side of at least one of the first and second electrodes and containing a compound for a capping layer represented by any one of Formulas 1 to 12. Here, among the two sides of the first electrode or the second electrode, the side adjacent to the organic layer interposed between the first electrode and the second electrode is referred to as the inner side, and the side not adjacent to the organic layer is referred to as the outer side. That is, when the capping layer is disposed on the outer side of the first electrode, the first electrode is interposed 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 is interposed between the capping layer and the organic layer.

[0150] According to one embodiment of the present invention, the organic light-emitting device may have various organic layers interposed between the inner sides of the first electrode and the second electrode, and a capping layer may be formed on the outer side of at least one of the first and second electrodes. The capping layer may be formed on both the outer side of the first electrode and the outer side of the second electrode, or may be disposed on the outer side of the first electrode or the outer side of the second electrode. The capping layer may include a compound for a capping layer according to the present invention. Furthermore, according to one embodiment of the present invention, an organic layer having various functions may be additionally formed on the outer sides of the first and second electrodes in which the capping layer is interposed. That is, a capping layer may be formed directly on the outer surface of the first electrode (or the second electrode), or an organic layer having various functions may be formed on the outer surface of the first electrode (or the second electrode), and a capping layer containing a compound of the present invention may be formed on said organic layer.

[0151] According to one embodiment of the present invention, the capping layer may include a compound for the capping layer according to one embodiment of the present invention alone, or two or more types or a known compound together.

[0152] An organic light-emitting device according to one embodiment of the present invention comprises one or more organic layers between the first and second electrodes, that is, on the inner side of the first and second electrodes, and a capping layer may be formed on the outer side of the first and second electrodes. The organic layers may generally be a hole transport layer, a light-emitting layer, and an electron transport layer constituting a light-emitting part, but may not be limited thereto.

[0153] The above organic light-emitting device may include one or more organic layers constituting a light-emitting portion, 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 a first electrode (anode) and a second electrode (cathode).

[0154] For example, the above organic light-emitting device can be manufactured as described in the structure of FIG. 1. The organic light-emitting device can be stacked in the order of a first electrode (hole injection electrode (1000)) / hole injection layer (200) / hole transport layer (300) / emissive layer (400) / electron transport layer (500) / electron injection layer (600) / second electrode (electron injection electrode (2000)) / capping layer (3000)) from the bottom.

[0156] In FIG. 1, the substrate (100) can be a substrate used in organic light-emitting devices, and in particular, it can be a transparent glass substrate or a flexible plastic substrate with excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.

[0157] The first electrode (1000) is used as an anode for hole injection in an organic light-emitting device. A material having a low work function is used to enable hole injection, and it can be formed from a transparent material such as indium tin oxide (ITO), indium zinc oxide (IZO), or graphene.

[0158] A hole injection layer (200) can be formed by depositing a hole injection layer material on the upper part of the first electrode by a method such as vacuum deposition, spin coating, casting, or the Langmuir-Blodgett (LB) method. When forming the hole injection layer by the vacuum deposition method, the deposition conditions vary depending on the compound used as the material for the hole injection layer (200), the structure and thermal characteristics of the desired hole injection layer, but generally, a deposition temperature of 50-500°C, 10 -8 to 10 -3 A vacuum of torr, a deposition rate of 0.01 to 100 Å / sec, and a layer thickness of 10 Å to 5 μm can be appropriately selected. Additionally, a charge generation layer can be additionally deposited on the surface of the hole injection layer as needed. Conventional materials can be used as the charge generation layer material, and HATCN can be cited as an example.

[0159] Next, a hole transport layer (300) can be formed by depositing a hole transport layer material on top of the hole injection layer (200) using a method such as vacuum deposition, spin coating, casting, or LB method. When forming the hole transport layer by the vacuum deposition method, the deposition conditions vary depending on the compound used, but generally, it is preferable to select conditions within a range that is almost identical to those for forming the hole injection layer.

[0160] The hole transport layer (300) can be formed using a known compound. According to one embodiment of the present invention, the hole transport layer (300) may be one or more layers, and a light-emitting auxiliary layer may be formed on the hole transport layer (300).

[0161] A light-emitting layer (400) can be formed by depositing a light-emitting layer material on the hole transport layer (300) or light-emitting auxiliary layer using a method such as vacuum deposition, spin coating, casting, or LB method. When forming the light-emitting layer by the vacuum deposition method, the deposition conditions vary depending on the compound used, but generally, it is preferable to select conditions within a range that is almost identical to those for forming the hole injection layer. Additionally, the light-emitting layer material may use a known compound as a host or dopant.

[0162] In addition, when used with a phosphorescent dopant in the emissive layer, a hole suppressor material (HBL) may be additionally deposited by vacuum deposition or spin coating to prevent triplet excitons or holes from diffusing into the electron transport layer. The hole suppressor material that can be used is not particularly limited, but any known material used as a hole suppressor material may be selected and used. Examples include oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, or the hole suppressor material described in Japanese Patent Publication No. 11-329734 (A1). Representative examples include Balq (bis(8-hydroxy-2-methylquinolinolnato)-aluminum biphenoxide) and phenanthroline-based compounds (e.g., UDC's BCP (vasocuproin)).

[0163] An electron transport layer (500) is formed on the upper portion of the light-emitting layer (400) formed as described above. At this time, the electron transport layer can be formed by methods such as vacuum deposition, spin coating, or casting. Additionally, although the deposition conditions of the electron transport layer vary depending on the compound used, it is generally preferable to select conditions within a range that is almost identical to those for forming the hole injection layer.

[0164] After that, an electron injection layer (600) can be formed by depositing an electron injection layer material on top of the electron transport layer (500), and at this time, the electron transport layer can be formed by a conventional electron injection layer material using a vacuum deposition method, a spin coating method, a casting method, etc.

[0165] The hole injection layer (200), hole transport layer (300), light-emitting layer (400), and electron transport layer (500) of the above organic light-emitting device may use the following materials, but are not limited thereto.

[0166]

[0167]

[0168]

[0170] A second electrode (2000) for electron injection is formed on the electron injection layer (600) by a method such as vacuum deposition or sputtering. Various metals can be used as the cathode. Specific examples include materials such as aluminum, gold, silver, and magnesium.

[0171] The organic light-emitting device of the present invention can be an organic light-emitting device having a structure of a first electrode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, a second electrode, and a capping layer, as well as an organic light-emitting device having a structure of various other structures, and it is also possible to form one or two intermediate layers as needed.

[0172] As described above, the thickness of each organic layer formed according to the present invention can be adjusted according to the required degree, specifically 10 to 1,000 nm, and more specifically 20 to 150 nm.

[0173] According to one embodiment of the present invention, a capping layer (3000) may be formed on the outer side of the electrode in which a hole injection layer (200) is interposed in the first electrode (1000). Additionally, a capping layer (3000) may be formed on the outer side of the electrode in which an electron injection layer (600) is interposed in the second electrode (2000). Although not limited thereto, the capping layer (3000) may be formed by a deposition process, and the thickness of the capping layer (3000) may be 100 to 1000 Å, and more specifically, 300 to 1000 Å. In this case, the transmittance of the capping layer may be prevented from decreasing.

[0174] In the organic light-emitting device according to the present aspect, all of the contents described in one aspect of the present invention may be applied, but are not limited thereto.

[0176] The following describes the invention in more detail through embodiments thereof, and the scope of the invention is not limited by these embodiments.

[0178] [Example]

[0179] Intermediate synthesis

[0180] For the synthesis of the target compound, the intermediate IM can be synthesized using the following reaction scheme.

[0181]

[0183] Preparation Example 1: Intermediate (IM1)

[0184]

[0185] 3.0 g of 1-bromo-4-phenylnaphthalene, 1.1 g of aniline, 1.5 g of t-BuONa, 30.4 g of Pd2(dba) and 0.5 ml of (t-Bu)3P were dissolved in 70 ml of toluene in a round-bottom flask and stirred under reflux. The reaction was monitored by TLC, and the reaction was terminated after adding water. The organic layer was extracted with MC, filtered under reduced pressure, and then column purified and recrystallized to obtain 2.1 g of IM1 (yield 67%).

[0187] IM2 to IM9 below were synthesized using different starting materials in the same way as IM1 above.

[0188]

[0190] IM2 starting material Starting material of IM3 IM4 starting material 3-Bromo-1-phenylnaphthalene, aniline 2-Bromo-6-phenylnaphthalene, aniline 2-Bromo-7-phenylnaphthalene, aniline IM5 starting material IM6 starting material IM7 starting material 2-Bromo-7-phenylnaphthalene, p-toluidine 2-Bromo-7-phenylnaphthalene, 4-fluoroaniline 2-Bromo-7-phenylnaphthalene, 4-aminobenzonitrile IM8 starting material IM9 starting material 2-Bromo-7-phenylnaphthalene, pyridine-3-amine 2-Bromo-7-phenylnaphthalene, [1,1'-biphenyl]-4-amine

[0192] Compound synthesis

[0193] Synthesis of Compound 1

[0194]

[0195] 2.0 g of IM1, 3.2 g of 4-bromo-4'-iodo-1,1'-biphenyl, 0.1 g of t-BuONa, 30.25 g of Pd2(dba)3, and 0.4 ml of (t-Bu)3P were dissolved in 80 ml of toluene in a round-bottom flask and stirred under reflux. The reaction was monitored by TLC, and the reaction was terminated after adding water. The organic layer was extracted with MC, filtered under reduced pressure, and then column purified and recrystallized to obtain 2.0 g of IM1-1 (yield 57%).

[0196] 2.0 g of IM1-1, 1.3 g of di([1,1'-biphenyl]-4-yl)amine, 0.6 g of t-BuONa, 30.15 g of Pd2(dba) and 0.2 ml of (t-Bu)3P were dissolved in 80 ml of toluene in a round-bottom flask and stirred under reflux. The reaction was monitored by TLC, and the reaction was terminated after adding water. The organic layer was extracted with MC, filtered under reduced pressure, and then column purified and recrystallized to obtain 2.0 g of Compound 1 (yield 69%).

[0197] m / z: 766.33 (100.0%), 767.34 (63.2%), 768.34 (20.1%), 769.34 (4.0%)

[0199] Synthesis of Compound 2

[0200]

[0201] Compound 2 was synthesized using IM2 instead of IM1 in the same manner as Compound 1 (yield 65%).

[0202] m / z: 766.33 (100.0%), 767.34 (63.2%), 768.34 (20.1%), 769.34 (4.0%)

[0204] Synthesis of Compound 3

[0205]

[0206] Compound 3 was synthesized using IM3 instead of IM1 in the same manner as Compound 1 (yield 67%).

[0207] m / z: 766.33 (100.0%), 767.34 (63.2%), 768.34 (20.1%), 769.34 (4.0%)

[0209] Synthesis of Compound 4

[0210]

[0211] Compound 4 was synthesized using IM4 instead of IM1 in the same manner as Compound 1 (yield 67%).

[0212] m / z: 766.33 (100.0%), 767.34 (63.2%), 768.34 (20.1%), 769.34 (4.0%)

[0214] Synthesis of Compound 5

[0215]

[0216] 1.0 g of IM2, 0.5 g of 4,4'-dibromo-1,1'-biphenyl, 0.5 g of t-BuONa, 30.12 g of Pd2(dba) and 0.1 ml of (t-Bu)3P were dissolved in 30 ml of toluene in a round-bottom flask and stirred under reflux. The reaction was monitored by TLC, and the reaction was terminated after adding water. The organic layer was extracted with MC, filtered under reduced pressure, and then column purified and recrystallized to obtain 1.8 g of Compound 5 (yield 72%).

[0217] m / z: 740.32 (100.0%), 741.32 (61.3%), 742.33 (18.3%), 743.33 (3.6%)

[0219] Synthesis of Compound 6

[0220]

[0221] Compound 6 was synthesized using IM3 instead of IM2 in the same manner as Compound 5 (yield 60%).

[0222] m / z: 740.32 (100.0%), 741.32 (61.3%), 742.33 (18.3%), 743.33 (3.6%)

[0224] Synthesis of Compound 7

[0225]

[0226] Compound 7 was synthesized using IM4 instead of IM2 in the same manner as Compound 5 (yield 63%).

[0227] m / z: 740.32 (100.0%), 741.32 (61.3%), 742.33 (18.3%), 743.33 (3.6%)

[0229] Synthesis of Compound 8

[0230]

[0231] Compound 8 was synthesized using IM5 instead of IM2 in the same manner as Compound 5 (yield 67%).

[0232] m / z: 768.35 (100.0%), 769.35 (63.5%), 770.36 (19.7%), 771.36 (4.0%)

[0234] Synthesis of Compound 9

[0235]

[0236] Compound 9 was synthesized using IM6 instead of IM2 in the same manner as Compound 5 (yield 62%).

[0237] m / z: 776.30 (100.0%), 777.30 (61.3%), 778.31 (18.3%), 779.31 (3.6%)

[0239] Synthesis of Compound 10

[0240]

[0241] Compound 10 was synthesized using IM7 instead of IM2 in the same manner as Compound 5 (yield 60%).

[0242] m / z: 790.31 (100.0%), 791.31 (64.2%), 792.32 (19.6%), 793.32 (4.0%)

[0244] Synthesis of Compound 11

[0245]

[0246] Compound 11 was synthesized using IM8 instead of IM2 in the same manner as Compound 5 (yield 58%).

[0247] m / z: 742.31 (100.0%), 743.31 (59.9%), 744.32 (17.0%), 745.32 (3.2%)

[0249] Synthesis of Compound 12

[0250]

[0251] Compound 12 was synthesized using IM9 instead of IM2 in the same manner as Compound 5 (yield 65%).

[0252] m / z: 892.38 (100.0%), 893.39 (74.1%), 894.39 (27.1%), 895.39 (6.7%), 896.40 (1.1%)

[0254] Synthesis of Compound 13

[0255]

[0256] Compound 13 was synthesized using IM4 and 2,7-dibromo-9,9-dimethyl-9H-fluorene instead of IM2 and 4,4'-dibromo-1,1'-biphenyl in the same manner as Compound 5 (yield 59%).

[0257] m / z: 780.35 (100.0%), 781.35 (64.6%), 782.36 (20.3%), 783.36 (4.2%)

[0259] Synthesis of Compound 14

[0260]

[0261] Compound 14 was synthesized in the same manner as Compound 5 using IM4 and 4,4''-dibromo-1,1':4',1''-terphenyl instead of IM2 and 4,4'-dibromo-1,1'-biphenyl (yield 70%).

[0262] m / z: 816.35 (100.0%), 817.35 (67.8%), 818.36 (22.5%), 819.36 (4.9%)

[0264] Synthesis of Compound 15

[0265]

[0266] 1.0 g of (4-aminophenyl)boronic acid and 2.6 g of 4-bromo-N,N-diphenylaniline were dissolved in 50 ml of 1,4-dioxane in a round-bottom flask, and 11 ml of K2CO3 (2M) and 40.3 g of Pd(PPh3) were added, followed by reflux stirring. The reaction was monitored by TLC, and the reaction was terminated after adding water. The organic layer was extracted with MC, filtered under reduced pressure, and recrystallized to obtain 1.5 g of intermediate OP15-1 (yield 62%).

[0267] 1.5 g of 2-bromo-7-phenylnaphthalene, 1.8 g of OP15-1, 0.75 g of t-BuONa, 30.2 g of Pd2(dba) and 0.2 ml of (t-Bu)3P were dissolved in 60 ml of toluene in a round-bottom flask and stirred under reflux. The reaction was monitored by TLC, and the reaction was terminated after adding water. The organic layer was extracted with MC, filtered under reduced pressure, and then column purified and recrystallized to obtain 2.5 g of Compound 15 (yield 64%).

[0268] m / z: 740.32 (100.0%), 741.32 (61.3%), 742.33 (18.3%), 743.33 (3.6%)

[0270] Organic light-emitting diode manufacturing

[0271] Example 1

[0272] On an ITO substrate on which a reflective layer containing Ag was formed, a hole injection layer HI01 600 Å, HATCN 50 Å, and a hole transport layer BPA 600 Å were deposited, and then a 250 Å film was deposited as an emissive layer by doping BH01:BD01 3%. Next, an electron transport layer of Alq3:Liq(1:1) 300 Å was deposited, and then LiF 10 Å was deposited to form an electron injection layer. Subsequently, MgAg was deposited to a thickness of 15 nm, and Compound 1 was deposited as a capping layer to a thickness of 650 Å on the cathode. An organic light-emitting diode was fabricated by encapsulating the device in a glove box.

[0274] Examples 2 to 15

[0275] An organic light-emitting diode was fabricated in the same manner as in Example 1, except that a capping layer was formed using compounds 2 to 15, respectively, instead of compound 1 in Example 1.

[0277] Comparative Examples 1 to 7

[0278] An organic light-emitting diode was fabricated in the same manner as in Example 1, except that the capping layer was formed using the following compounds Ref. 1 to Ref. 7 respectively instead of compound 1 in Example 1 above.

[0279]

[0281] [Performance Evaluation of Organic Light Emitting Diodes]

[0282] The performance of the organic light-emitting diodes of the examples and comparative examples was evaluated by applying voltage to inject electrons and holes using a Keithley 2400 source measurement unit and measuring the luminance when light is emitted using a Konica Minolta spectroradiometer (CS-2000), and measuring the current density and luminance with respect to the applied voltage under atmospheric pressure conditions, and the results are shown in [Table 2] below.

[0284] Op. V mA / cm 2 Cd / A CIEy CIEy LT97 Example 1 3.8 10 5.92 0.141 0.052 120 Example 2 3.7 10 6.11 0.141 0.051 142 Example 3 3.7 10 6.12 0.141 0.051 145 Example 4 3.6 10 6.10 0.140 0.051 141 Example 5 3.7 10 6.31 0.140 0.050 150 Example 6 3.7 10 6.30 0.140 0.050 152 Example 7 3.7 10 6.30 0.139 0.050 150 Example 8 3.6 10 6.55 0.138 0.050 176 Example 9 3.7 10 6.45 0.139 0.047 160 Example 10 3.7 10 6.43 0.138 0.047 162 Example 11 3.6 10 6.42 0.139 0.047 160 Example 12 3.7 10 6.69 0.139 0.049 170 Example 13 3.7 10 6.50 0.139 0.049 173 Example 14 3.7 10 6.67 0.138 0.049 168 Example 15 3.7 10 6.53 0.138 0.049 157 Comparative Example 1 3.8 10 4.81 0.138 0.056 60 Comparative Example 2 3.7 10 4.75 0.136 0.057 65 Comparative Example 3 3.7 10 4.86 0.135 0.057 71 Comparative Example 4 3.8 10 4.80 0.136 0.058 64 Comparative Example 5 3.8 10 4.82 0.136 0.057 62 Comparative Example 6 3.7 10 4.81 0.135 0.058 75 Comparative Example 7 3.8 10 4.70 0.134 0.060 67

[0285] As shown in Table 2 above, it can be seen that the embodiments of the present invention have significantly improved high luminous efficiency, color purity, and lifespan compared to Comparative Examples 1 to 7.

[0286] More specifically, compared to Comparative Examples 1 to 7, the embodiments of the present invention have naphthalene directly bonded to nitrogen (N) with aryl substituents, which significantly improves external luminescence efficiency and color coordinates through high refractive index, and excellent thin film alignment due to increased phi conjugation, enabling the formation of a stable thin film and facilitating the prevention of contamination inside the device from external air and moisture. At the same time, it is stable against heat generated when operating at high Tg and Td, and is effective in improving lifespan. In addition, it can be seen that naphthalene directly bonded to nitrogen (N) with aryl substituents can have a broad absorption wavelength in the ultraviolet region, and as a result, excellent stability against external ultraviolet exposure leads to a significantly improved lifespan.

[0288] [Refractive Index Evaluation]

[0289] Compounds 6 and 12 of the present invention and Compound 1 of Ref. 1 were each used to deposit a film with a thickness of 30 nm on a silicon substrate using vacuum deposition equipment, and the refractive index at a wavelength of 450 nm was measured using an ellipsometer (JA Woollam Co. Inc, M-2000X). The results are summarized in Table 3 below.

[0290] @450nm Ref.1 Compound 6 Compound 12 Refractive index, n 1.98 2.20 2.27

[0291] As shown in Table 3 above, it was confirmed that the compound of Ref. 1 has a refractive index of less than 2.0 at 450 nm, whereas the compounds 6 and 12 of the present invention have a refractive index of 2.1 or higher, and more specifically, a high refractive index of 2.2 or higher.

[0293] [Evaluation of Absorption Intensity in the Ultraviolet Region]

[0294] Compounds 6 and 12 of the present invention and Compound 1 of Ref. 1 were each used to deposit a film with a thickness of 30 nm on a silicon substrate using vacuum deposition equipment, and the absorption intensity in the wavelength range of 320 nm to 450 nm was measured using an ellipsometer (JA Woollam Co. Inc, M-2000X). The results are as shown in Fig. 2.

[0295] As shown in Figure 2, at 380 nm in the ultraviolet region, the absorption intensity of the compound of Ref. 1 was less than 0.5, whereas the absorption intensity of compounds 6 and 12 of the present invention was 0.5 or higher, more specifically 0.6 or higher, and it was confirmed that the absorption intensity of the compound of Ref. 1 was increased by about 25% or more, and as high as 50% or more.

[0297] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical concept or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0298] The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and all modifications or variations derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0300] 100: Substrate 200: Hole injection layer 300: Precision Transport Layer 400: Emitting layer 500: Electron transport layer 600: Electron injection layer 1000: Anode (first electrode) 2000: Cathode (second electrode) 3000: Capping layer

Claims

Claim 1 A capping layer disposed on the outer side of either the first electrode or the second electrode of an organic light-emitting diode, Compound for a capping layer represented by the following chemical formula 1 capping layer including ; [Chemical Formula 1] In the above Chemical Formula 1, Ar, Ar1 to Ar3 are each independently substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 2~50 It is a heteroaryl group, and L is a substituted or unsubstituted C 6~50 The arylene group of, or substituted or unsubstituted C 2~50 It is a heteroarylene group, where R1 is hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group of, or substituted or unsubstituted C 1~30 It is a sulfide group, and l is an integer from 1 to 6. Claim 2 In claim 1, the above chemical formula 1 is represented by the following chemical formula 2 or chemical formula 3, capping layer ;[Chemical Formula 2] [Chemical Formula 3] In the above Chemical Formula 2 or Chemical Formula 3, Ar' is independently substituted or unsubstituted C, respectively. 6~40 The aryl group of, or substituted or unsubstituted C 2~40 It is a heteroaryl group, and m is an integer from 1 to 7. Claim 3 In claim 1, the above chemical formula 1 is represented by any one of the following chemical formulas 4 to 6, capping layer ;[Chemical Formula 4] [Chemical Formula 5] [Chemical Formula 6] In the above chemical formulas 4 to 6, X is O, S, NAr4, or CRR', and Ar4 is hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group, and L1 and L2 are each independently directly bonded, substituted, or unsubstituted C 6~38 The arylene group of, or substituted or unsubstituted C 2~38 It is a heteroarylene group, and R and R' are each independently hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group, where adjacent R and R' may or may not form a ring, and Ar' is each independently substituted or unsubstituted C 6~40 The aryl group of, or substituted or unsubstituted C 2~40 It is a heteroaryl group, m is an integer from 1 to 7, and n is an integer from 0 or 1 to 4. Claim 4 In claim 1, the above chemical formula 1 is represented by any one of the following chemical formulas 7 to 9, capping layer ;[Chemical Formula 7] [Chemical Formula 8] [Chemical Formula 9] In the above chemical formulas 7 to 9, X is O, S, NAr4, or CRR', and Ar4 is hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group, where R and R' are each independently hydrogen, deuterium, halogen, nitro group, nitrile group, or substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group, where adjacent R and R' may or may not form a ring, and Ar' is a substituted or unsubstituted C 6~40 The aryl group of, or substituted or unsubstituted C 2~40 It is a heteroaryl group, and Ar2' is a substituted C 6~50 ui Arilgi, Non-replaced C 10~50 The aryl group of, or substituted or unsubstituted C 2~50 It is a heteroaryl group. Claim 5 In claim 1, the above chemical formula 1 is represented by any one of the following chemical formulas 10 to 12, capping layer ;[Chemical Formula 10] [Chemical Formula 11] [Chemical Formula 12] In the above chemical formulas 10 to 12, X is O, S, NAr4, or CRR', and Ar4 is hydrogen, deuterium, halogen, nitro group, nitrile group, substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group, where R and R' are each independently hydrogen, deuterium, halogen, nitro group, nitrile group, or substituted or unsubstituted C 1~30 alkyl groups of, substituted or unsubstituted C 2~30 The alkenyl group of, substituted or unsubstituted C 1~30 The alkoxy group, substituted or unsubstituted C 1~30 The sulfide group of, substituted or unsubstituted C 6~50 The aryl group of, or substituted or unsubstituted C 5~50 It is a heteroaryl group, where adjacent R and R' may or may not form a ring, and Ar' is a substituted or unsubstituted C 6~40 The aryl group of, or substituted or unsubstituted C 2~40 It is a heteroaryl group, and Ar2' is a substituted C 6~50 ui Arilgi, Non-replaced C 10~50 The aryl group of, or substituted or unsubstituted C 2~50 It is a heteroaryl group. Claim 6 In claim 1 or 2, the above L is selected from the group consisting of phenylene, biphenylene, terphenylene, naphthylene, phenanthrenylene, fluorenylene, and combinations thereof, capping layer . Claim 7 A capping layer according to any one of claims 1 to 5, wherein Ar, Ar1 to Ar2 and Ar3 of claims 1 to 3 are each independently selected from the group consisting of phenyl, naphthyl, biphenyl, terphenyl, pyridinyl and combinations thereof, Ar4 of claims 3 to 5 and Ar' of claims 2 to 5 are each independently selected from the group consisting of phenyl, naphthyl, biphenyl, terphenyl, pyridinyl and combinations thereof, and Ar2' of claims 4 and 5 is selected from the group consisting of toluenyl, naphthyl, biphenyl, terphenyl, pyridinyl and combinations thereof. Claim 8 A capping layer according to any one of claims 1 to 5, wherein Ar, Ar1 to Ar2 and Ar3 of claims 1 to 3, Ar4 of claims 3 to 5, Ar' of claims 2 to 5 and Ar2' of claims 4 and 5 each independently have one or more substituents selected from the group consisting of alkyl groups, alkoxy groups, sulfide groups, halogens, cyano groups and combinations thereof. Claim 9 In claim 1, the above chemical formula 1 is any one of the following compounds, capping layer ; . Claim 10 A first electrode and a second electrode; an organic layer interposed between the first electrode and the second electrode; and disposed outside of either the first electrode or the second electrode, and Article 1 capping layer according to Organic light-emitting diode including ; Claim 11 An organic light-emitting device according to claim 10, wherein the thickness of the capping layer is 100 to 1000 Å.

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