Organic electroluminescent device and polycyclic compound for organic electroluminescent device

Abstract

The present application relates to an organic electroluminescent device and a polycyclic compound for an organic electroluminescent device. The organic electroluminescent device comprises a first electrode, sandwiched by the following layers: a hole transport region arranged on the first electrode, an emission layer arranged on the hole transport region, and an electron transport region arranged on the emission layer. The emission layer comprises a polycyclic compound represented by the following structure: #imgabs0# wherein X 1 To X 10 Each of R is independently carbon or nitrogen, and R 1 To R 5 Each of X is independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted amine group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring. 1 To X 10 If both are carbon, then R 4 and R 5 At least one of the is a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2018-0135437, filed on November 6, 2018, which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure herein relates to organic electroluminescent devices and polycyclic compounds used in organic electroluminescent devices. Background Art

[0004] Recently, much effort has been put into the development of organic electroluminescent display devices as image display devices. Unlike liquid crystal display devices, organic electroluminescent display devices are self-luminous display devices in which holes and electrons injected from a first electrode and a second electrode are recombined in an emission layer. The emission layer contains a light emitting material including an organic compound, and emits light to display an image.

[0005] In the application of organic electroluminescent devices to display devices, lower driving voltage, improved emission efficiency and longer life of the organic electroluminescent devices are desired. Therefore, research and development of materials for organic electroluminescent devices capable of stably achieving these characteristics are being conducted.

[0006] In particular, recently, in order to realize an organic electroluminescent device with high efficiency, technology based on phosphorescence emission (which uses triplet energy) or delayed fluorescence emission (which uses the generation phenomenon of singlet excitons through collision of triplet excitons (triplet-triplet annihilation, TTA)) is being developed, and development of materials for thermally activated delayed fluorescence (TADF) using the delayed fluorescence phenomenon is being carried out. Summary of the invention

[0007] The present disclosure provides an organic electroluminescent device having a long lifetime and high efficiency, and a polycyclic compound used therein.

[0008] The present disclosure also provides an organic electroluminescent device including a material for emitting thermally activated delayed fluorescence and a polycyclic compound serving as the material for emitting thermally activated delayed fluorescence.

[0009] Embodiments of the inventive concept provide an organic electroluminescent device including a first electrode, a hole transport region disposed on the first electrode, an emission layer disposed on the hole transport region, an electron transport region disposed on the emission layer, and a second electrode disposed on the electron transport region, wherein the emission layer includes a polycyclic compound represented by the following Formula 1:

[0010] [Formula 1]

[0011]

[0012] In formula 1, X 1 To X 10 are each independently carbon or nitrogen, R 1 To R 5 each independently represents a hydrogen atom, a deuterium atom, a substituted or unsubstituted amine group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring, "a" and "b" are each independently an integer from 0 to 4, "c" is an integer from 0 to 3, and "d" and "e" are each independently an integer from 0 to 5, wherein if all X 1 To X 10 If both are carbon, then R 4 and R 5 At least one of the is a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring.

[0013] In an embodiment, the emitting layer may emit delayed fluorescence.

[0014] In an embodiment, the emission layer may be a delayed fluorescence emission layer including a host and a dopant, and the dopant may include the polycyclic compound.

[0015] In an embodiment, the emission layer may be a thermally activated delayed fluorescent emission layer that emits blue light.

[0016] In an embodiment, Formula 1 may be represented by the following Formula 2:

[0017] [Formula 2]

[0018]

[0019] In formula 2, Ar 1 and Ar 2 are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring, "f" is an integer of 0 to 3, and X 1 To X 10 , R 1 To R 5 , “a” and “c” to “e” are the same as defined in Formula 1.

[0020] In an embodiment, Formula 1 may be represented by the following Formula 3:

[0021] [Formula 3]

[0022]

[0023] In formula 3, R 4 and R 5 are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring, R 4 and R 5 At least one of is a substituted or unsubstituted N-containing heteroaryl group having 2 to 30 carbon atoms, and R 1 To R 3 and "a" to "e" are the same as defined in Formula 1.

[0024] In an embodiment, Formula 3 may be represented by the following Formula 4:

[0025] [Formula 4]

[0026]

[0027] In formula 4, Y 1 To Y 5 are each independently carbon or nitrogen, Y 1 To Y 5 At least one of them is nitrogen, R 6 is a hydrogen atom, a deuterium atom, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring, "g" is an integer of 0 to 4, "h" is an integer of 0 to 4, and R 1 To R 5 , “a” to “c” and “e” are the same as defined in Formula 3.

[0028] In an embodiment, Formula 4 may be represented by the following Formula 5:

[0029] [Formula 5]

[0030]

[0031] In formula 5, Ar 1 and Ar 2 are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring, "f" is an integer of 0 to 3, and R 1 To R 6 , Y 1 To Y 5, “a”, “c”, “e”, “g” and “h” are the same as defined in Formula 4.

[0032] In an embodiment, Formula 1 may be represented by the following Formula 6:

[0033] [Formula 6]

[0034]

[0035] In formula 6, X 1 To X 5 are each independently carbon or nitrogen, X 1 To X 5 At least one of them is nitrogen, "g" is an integer from 0 to 4, and R 1 To R 5 , “a” to “c” and “e” are the same as defined in Formula 1.

[0036] In an embodiment, Formula 6 may be represented by the following Formula 7:

[0037] [Formula 7]

[0038]

[0039] In formula 7, Ar 1 and Ar 2 are each independently a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring, "f" is an integer of 0 to 3, and X 1 To X 5 , R 1 To R 5 , “a”, “c”, “e” and “g” are the same as defined in Formula 6.

[0040] In formula 7, X 1 To X 5 Two of them can be nitrogen.

[0041] In an embodiment, the compound represented by Formula 1 may be any one of the compounds represented in Compound Group 1.

[0042] In an embodiment, the compound represented by Formula 1 may be any one of the compounds represented in Compound Group 2.

[0043] In an embodiment of the present inventive concept, a polycyclic compound represented by Formula 1 is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings are included to provide a further understanding of the inventive concept and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate exemplary embodiments of the inventive concept and together with the description serve to explain the principles of the inventive concept. In the drawings:

[0045] Figure 1 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present inventive concept;

[0046] Figure 2 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present inventive concept; and

[0047] Figure 3 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the inventive concept. DETAILED DESCRIPTION

[0048] The present invention may have various modifications and may be implemented in different forms, and exemplary embodiments will be explained in detail with reference to the accompanying drawings. However, the present invention may be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, all modifications, equivalents and substitutions included in the gist and technical scope of the present invention should be included in the present invention.

[0049] The same reference numerals refer to the same elements throughout the text. In the accompanying drawings, the size of the structure is enlarged for clarity of illustration. It should be understood that although the terms first, second, etc. can be used to describe different elements in this article, these elements should not be limited to these terms. These terms are only used to distinguish one element from another element. Therefore, without departing from the teachings of the present invention, the first element can be referred to as the second element. Similarly, the second element can be referred to as the first element. As used herein, the singular form is intended to also include the plural form, unless the context clearly indicates otherwise.

[0050] It should also be understood that the terms "comprises" and / or "comprising" when used in this specification specify the presence of the features, numbers, steps, operations, elements, components or combinations thereof, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, components or combinations thereof. It should also be understood that when a layer, film, region, plate, etc. is referred to as being "on" another component, it can be "directly" "on" another component, or there may be intervening layers.

[0051] In the following, reference will be made to Figures 1 to 3 An organic electroluminescent device according to an embodiment of the inventive concept is explained.

[0052] refer to Figures 1 to 3 , the organic electroluminescent device 10 according to the embodiment may include a first electrode EL1 , a hole transport region HTR, an emission layer EML, an electron transport region ETR, and a second electrode EL2 which are laminated one by one.

[0053] The first electrode EL1 and the second electrode EL2 are arranged opposite to each other, and a plurality of organic layers may be arranged between the first electrode EL1 and the second electrode EL2. The plurality of organic layers may include a hole transport region HTR, an emission layer EML, and an electron transport region ETR. The organic electroluminescent device 10 of the embodiment may include the polycyclic compound of the embodiment in the emission layer EML.

[0054] At the same time, when Figure 1 When compared, Figure 2 A cross-sectional view of an organic electroluminescent device 10 of an embodiment is shown, wherein the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL, and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL. Figure 1 When compared, Figure 3 A cross-sectional view of an organic electroluminescent device 10 of an embodiment is shown, wherein the hole transport region HTR includes a hole injection layer HIL, a hole transport layer HTL, and an electron blocking layer EBL, and the electron transport region ETR includes an electron injection layer EIL, an electron transport layer ETL, and a hole blocking layer HBL.

[0055] In the organic electroluminescent device 10 of the embodiment, the first electrode EL1 has conductivity. The first electrode EL1 may be formed using a metal alloy or a conductive compound. The first electrode EL1 may be an anode.

[0056] The first electrode EL1 may be a transmissive electrode, a semi-transmissive reflective electrode or a reflective electrode. If the first electrode EL1 is a transmissive electrode, a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO) and indium tin zinc oxide (ITZO) may be used to form the first electrode EL1. If the first electrode EL1 is a semi-transmissive reflective electrode or a reflective electrode, the first electrode EL1 may contain Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, a compound thereof or a mixture thereof (e.g., a mixture of Ag and Mg). In addition, the first electrode EL1 may have a structure including a plurality of layers including a reflective layer or a semi-transmissive reflective layer formed using the above materials, and a transmissive conductive layer formed using ITO, IZO, ZnO or ITZO. For example, the first electrode EL1 may include a plurality of layers of ITO / Ag / ITO.

[0057] A hole transport region HTR is provided on the first electrode EL1. The hole transport region HTR may include at least one of a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer, and an electron blocking layer EBL.

[0058] The hole transport region HTR may have a single layer formed using a single material, a single layer formed using a plurality of different materials, or a multi-layer structure including a plurality of layers formed using a plurality of different materials.

[0059] For example, the hole transport region HTR may have a single-layer structure of a hole injection layer HIL or a hole transport layer HTL, or may have a single-layer structure formed using a hole injection material and a hole transport material. Alternatively, the hole transport region HTR may have a single-layer structure formed using a plurality of different materials, or a structure of a hole injection layer HIL / hole transport layer HTL, a hole injection layer HIL / hole transport layer HTL / hole buffer layer, a hole injection layer HIL / hole buffer layer, a hole transport layer HTL / hole buffer layer, or a hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL laminated from the first electrode EL1 without limitation.

[0060] The hole transport region HTR may be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB), inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0061] The hole injection layer HIL of the organic electroluminescent device 10 of the embodiment may include a known hole injection material. For example, the hole injection layer HIL may include triphenylamine-containing polyetherketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate (PPBI), N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-phenyl-4,4'-diamine (DNTPD), a phthalocyanine compound such as copper phthalocyanine, 4,4',4"-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB), N,N'-bis(1-naphthyl)-N,N'-diphenyl-4,4'-diamine (α-NPD), 4,4' ,4"-tri{N,N-diphenylamino}triphenylamine (TDATA), 4,4',4"-tri(N,N-2-naphthylphenylamino)triphenylamine (2-TNATA), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), or dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN). However, embodiments of the inventive concept are not limited thereto.

[0062] The hole transport layer HTL of the organic electroluminescent device 10 of the embodiment may include a known hole transport material. For example, the hole transport layer HTL may include 4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline] (TAPC), carbazole derivatives (such as N-phenylcarbazole and polyvinylcarbazole), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD), 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA), N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB), N,N'-bis(1-naphthyl)-N,N'-diphenyl-4,4'-diamine (α-NPD), etc. However, the embodiments of the inventive concept are not limited thereto.

[0063] Meanwhile, the hole transport region HTR may further include an electron blocking layer EBL, and the electron blocking layer EBL may be disposed between the hole transport layer HTL and the emission layer EML. The electron blocking layer EBL may play a role in preventing electron injection from the electron transport region ETR to the hole transport region HTR.

[0064] The electron blocking layer EBL may include common materials known in the art. The electron blocking layer EBL may include, for example, carbazole derivatives (e.g., N-phenylcarbazole and polyvinylcarbazole), fluorine-based derivatives, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD), triphenylamine-based derivatives (e.g., 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA)), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPD), 4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3,3'-tolyl)amino]-3,3'-dimethylbiphenyl (HMTPD), mCP, etc. In addition, as described above, the electron blocking layer EBL may include a polycyclic compound according to an embodiment of the inventive concept.

[0065] The thickness of the hole transport region HTR may be about to about For example, about to about The thickness of the hole injection layer HIL may be, for example, about to about And the thickness of the hole transport layer HTL can be about to about For example, the thickness of the electron blocking layer EBL may be about to about If the thicknesses of the hole transport region HTR, the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer EBL satisfy the above ranges, satisfactory hole transport properties may be achieved without a significant increase in driving voltage.

[0066] In addition to the above materials, the hole transport region HTR may further include a charge generating material to improve conductivity. The charge generating material may be uniformly or non-uniformly dispersed in the hole transport region HTR. The charge generating material may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, or a compound containing a cyano group, without limitation. For example, non-limiting examples of p-dopants may include quinone derivatives (e.g., tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ)), metal oxides (e.g., tungsten oxide and molybdenum oxide), without limitation.

[0067] As described above, in addition to the hole injection layer HIL and the hole transport layer HTL, the hole transport region HTR may further include at least one of a hole buffer layer and an electron blocking layer EBL. The hole buffer layer may compensate for the resonance distance according to the wavelength of light emitted from the emission layer EML and increase the light emission efficiency. The material contained in the hole transport region HTR may be used as the material contained in the hole buffer layer.

[0068] An emission layer EML is provided on the hole transport region HTR. The emission layer EML may have, for example, about to about The emission layer EML may have a single layer formed using a single material, a single layer formed using a plurality of different materials, or a multilayer structure having a plurality of layers formed using a plurality of different materials.

[0069] The emission layer EML may emit one of red light, green light, blue light, white light, yellow light, and cyan light. The emission layer EML may include a fluorescent emission material or a phosphorescent emission material.

[0070] In an embodiment, the emission layer EML may be a fluorescent emission layer. For example, a portion of the light emitted from the emission layer EML may be attributed to thermally activated delayed fluorescence (TADF). In particular, the emission layer EML may include a luminescent component that emits thermally activated delayed fluorescence. In an embodiment, the emission layer EML may be an emission layer that emits thermally activated delayed fluorescence, which emits blue light.

[0071] In the description, -* means the connection position.

[0072] In the description, the term "substituted or unsubstituted" corresponds to being substituted or unsubstituted by at least one substituent selected from the group consisting of: deuterium atoms, halogen atoms, cyano groups, nitro groups, amine groups, silyl groups, boron groups, phosphine oxide groups, phosphine sulfide groups, alkyl groups, alkenyl groups, aryl groups and heterocyclic groups. In addition, each of the substituents can be substituted or unsubstituted. For example, a biphenyl group can be understood as an aryl group or a phenyl group substituted by a phenyl group.

[0073] In the description, the halogen atom may be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

[0074] In the description, the alkyl group may be a linear, branched or cyclic type. The carbon number of the alkyl group may be 1 to 50, 1 to 30, 1 to 20, 1 to 10 or 1 to 6. Examples of the alkyl group may include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyldecyl, 2-Hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, n-heonicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, n-triacontyl and the like without limitation.

[0075] In the description, an aryl group means a functional group or a substituent derived from an aromatic hydrocarbon ring. The aryl group can be a monocyclic aryl group or a polycyclic aryl group. The number of carbon atoms used to form the ring in the aryl group can be 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups can include phenyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl, biphenyl, terphenyl, quaterphenyl, pentaphenyl, hexaphenyl, triphenylenyl, pyrenyl, benzofluoranthenyl, Base, etc., without restriction.

[0076] In the description, the fluorenyl group may be substituted, and two substituents may be combined with each other to form a spiro structure. Examples of substituted fluorenyl groups are as follows. However, embodiments of the inventive concept are not limited thereto.

[0077]

[0078] In the description, heteroaryl can be a heteroaryl containing at least one of O, N, P, Si and S as a heteroatom. The carbon number of heteroaryl for forming a ring can be 2 to 30 or 2 to 20, and the number of heteroatoms for forming a ring of heteroaryl can be 1 to 10 or 1 to 5, such as 1, 2, 3, 4 or 5. Heteroaryl can be a monocyclic heteroaryl or a polycyclic heteroaryl. Examples of polycyclic heteroaryl can have a bicyclic or tricyclic structure. Examples of heteroaryl can include thienyl, furyl, pyrrolyl, imidazolyl, oxazolyl, triazolyl, pyridyl, bipyridyl, pyrimidyl, triazine, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolinyl, quinoxalinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, N-arylcarbazolyl, oxazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothiophenyl, dibenzothiophenyl, thienothiphenyl, benzofuranyl, phenanthroline, thiazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, benzothiazolyl, phenothiazinyl, dibenzothiorol, dibenzofuranyl and the like, without limitation.

[0079] In the description, the carbon number of the amine group is not particularly limited, but can be 1 to 30. The amine group can include an alkylamine group and an arylamine group. Examples of the amine group include a methylamine group, a dimethylamine group, a phenylamine group, a naphthylamine group, a 9-methyl-anthrylamine group, a triphenylamine group, etc., without limitation.

[0080] In the embodiment, the emission layer EML includes a polycyclic compound represented by Formula 1.

[0081] [Formula 1]

[0082]

[0083] In formula 1, X 1 To X 10 Each independently may be carbon or nitrogen.

[0084] In formula 1, R 1 To R 5 Each may independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted amine group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring.

[0085] At the same time, R 1 To R 5 Alkyl groups, in particular, cyclic alkyl groups, are excluded. If R 1 To R 5Including an alkyl group, although having a heteroaryl group as a substituent, the orbital spacing between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) is insufficient due to the multiple resonance effect, and if applied in a device, the half width of the emission layer is reduced to about 30 nm or less, and the rate of reverse intersystem crossing (RISC) for converting the triplet energy level (T1) to the singlet energy level (S1) is insufficient.

[0086] In Formula 1, "a" and "b" are each independently an integer of 0 to 4. Meanwhile, if "a" is 2 or more, then the plurality of R 1 The groups are the same or different, and if "b" is 2 or more, then multiple R 2 The groups are the same or different.

[0087] In Formula 1, "c" is an integer from 0 to 3. Meanwhile, if "c" is 2 or more, the plurality of R 3 The groups are the same or different.

[0088] In Formula 1, "d" and "e" are each independently an integer of 0 to 5. Meanwhile, if "d" is 2 or more, then the plurality of R 4 The groups are the same or different, and if "e" is 2 or more, then multiple R 5 The groups are the same or different.

[0089] In formula 1, if all X 1 To X 10 If both are carbon, then R 4 and R 5 At least one of is a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring. In this case, "d" and "e" are not 0 at the same time.

[0090] In the polycyclic compound according to the present invention, the ring structure formed by NBN The moiety may be an electron donor, and the nitrogen bonded to the electron donor Part and / or Part may be an electron acceptor. However, the embodiments of the present inventive concept are not limited thereto. The polycyclic compound comprises an electron acceptor, which is bonded to the nitrogen of the electron donor and delocalizes the electron density in the molecule, thereby reducing the absolute value (ΔEst) of the difference between the singlet energy level (S1) and the triplet energy level (T1), and increasing the rate constant of the reverse intersystem crossing (RISC) of converting the triplet energy level (T1) to the singlet energy level (S1). Therefore, the life of the organic electroluminescent device can be increased.

[0091] In an embodiment, Formula 1 may include an arylamine group as a substituent. In this case, Formula 1 may be represented by Formula 2.

[0092] [Formula 2]

[0093]

[0094] In formula 2, Ar 1 and Ar 2 Each may independently be a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring.

[0095] In Formula 2, "f" may be an integer from 0 to 3. Meanwhile, if "f" is 2 or greater, then the plurality of R 2 The groups are the same or different.

[0096] In formula 2, X 1 To X 10 , R 1 To R 5 , “a” and “c” to “e” are the same as defined in Formula 1.

[0097] In an embodiment, all X in Formula 1 1 To X 10 In this case, Formula 1 can be represented by Formula 3.

[0098] [Formula 3]

[0099]

[0100] In formula 3, R 4 and R 5 R may be each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring. 4 and R 5 At least one of may be a substituted or unsubstituted N-containing heteroaryl group having 2 to 30 carbon atoms. In this case, "d" and "e" are not 0 at the same time.

[0101] In formula 3, R 1 To R 3 and "a" to "e" are the same as defined in Formula 1.

[0102] In an embodiment, in a polycyclic compound, a N-containing heteroaryl group that is an electron acceptor may be bonded to N that is an electron donor.

[0103] In an embodiment, if R of Formula 3 4 is a heteroaryl group containing N, Formula 3 can be represented by Formula 4.

[0104] [Formula 4]

[0105]

[0106] In formula 4, Y 1 To Y 5 can each independently be carbon or nitrogen, and Y 1 To Y 5 At least one of may be nitrogen.

[0107] In formula 4, R 6 It may be a hydrogen atom, a deuterium atom, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring.

[0108] In Formula 4, "g" may be an integer from 0 to 4. Meanwhile, if "g" is 2 or more, the plurality of R 4 The groups are the same or different. Meanwhile, "g" of Formula 4 is an integer smaller than "d" of Formula 3. For example, if "d" is 1, "g" is 0.

[0109] In Formula 4, "h" is an integer from 0 to 4. Meanwhile, if "h" is 2 or more, the plurality of R 6 The groups are the same or different.

[0110] In formula 4, R 1 To R 5 , “a” to “c” and “e” are the same as defined in Formula 3.

[0111] In an embodiment, Formula 4 may include an arylamine group as a substituent. In this case, Formula 4 may be represented by Formula 5.

[0112] [Formula 5]

[0113]

[0114] In formula 5, Ar 1 and Ar 2 Each may independently be a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring.

[0115] In Formula 5, "f" is an integer from 0 to 3. Meanwhile, if "f" is 2 or more, the plurality of R 2The groups are the same or different. Meanwhile, "f" of Formula 5 is an integer smaller than "b" of Formula 4. For example, if "b" is 1, "f" is 0.

[0116] In Formula 5, R 1 To R 6 , Y 1 To Y 5 , “a”, “c”, “e”, “g” and “h” are the same as defined in Formula 4.

[0117] In an embodiment, the polycyclic compound may include a pyridine group as an electron acceptor, and in this case, Y of Formula 4 or Formula 5 1 To Y 5 One of the nitrogen may be nitrogen.

[0118] In an embodiment, all X of Formula 1 6 To X 10 In this case, Formula 1 can be represented by Formula 6.

[0119] [Formula 6]

[0120]

[0121] In formula 6, X 1 To X 5 may each independently be carbon or nitrogen, and X 1 To X 5 At least one of may be nitrogen.

[0122] In Formula 6, "g" is an integer from 0 to 4. Meanwhile, if "g" is 2 or more, the plurality of R 4 The groups are the same or different. Meanwhile, "g" of Formula 6 is an integer smaller than "d" of Formula 1. For example, if "d" is 1, "g" is 0.

[0123] In formula 6, R 1 To R 5 , “a” to “c” and “e” are the same as defined in Formula 1.

[0124] In an embodiment, Formula 6 may include an arylamine group as a substituent. In this case, Formula 6 may be represented by Formula 7.

[0125] [Formula 7]

[0126]

[0127] In formula 7, Ar 1 and Ar 2Each may independently be a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring.

[0128] In Formula 7, "f" is an integer from 0 to 3. Meanwhile, if "f" is 2 or more, the plurality of R 2 The groups are the same or different. Meanwhile, "f" of Formula 7 is an integer smaller than "b" of Formula 6. For example, if "b" is 1, "f" is 0.

[0129] In formula 7, X 1 To X 5 , R 1 To R 5 , “a”, “c”, “e” and “g” are the same as defined in Formula 6.

[0130] In the embodiment, in the polycyclic compound, the pyrimidine group as an electron acceptor may be bonded to N as an electron donor. In this case, X in Formula 7 1 To X 5 Two of them can be nitrogen.

[0131] The polycyclic compound of the embodiment represented by Formula 1 may be a material for emitting delayed fluorescence. The polycyclic compound of the embodiment may be a material for thermally activated delayed fluorescence.

[0132] For example, the polycyclic compound represented by Formula 1 has a small difference between the singlet energy level (S1) and the triplet energy level (T1), and can be used as a material for emitting thermally activated delayed fluorescence. In particular, the polycyclic compound represented by Formula 1 can be used as a blue emitting material emitting thermally activated delayed fluorescence. However, the embodiments of the inventive concept are not limited thereto. The polycyclic compound of the embodiment can be used as a material for thermally activated delayed fluorescence, which emits green light or red light.

[0133] The polycyclic compound of the embodiment represented by Formula 1 may be any one of the compounds represented in the following Compound Group 1:

[0134] [Compound Group 1]

[0135]

[0136] The polycyclic compound of the embodiment represented by Formula 1 may be any one of the compounds represented in the following Compound Group 2:

[0137] [Compound Group 2]

[0138]

[0139] The polycyclic compound represented by Formula 1 is used in the organic electroluminescent device 10 of the embodiment, and can improve the efficiency and life of the organic electroluminescent device. In particular, the polycyclic compound represented by Formula 1 is used in the emission layer EML of the organic electroluminescent device 10 of the embodiment, and can improve the emission efficiency and life of the organic electroluminescent device.

[0140] In the embodiment, the emission layer EML includes a host and a dopant, and the host can be a host for emitting delayed fluorescence, and the dopant can be a dopant for emitting delayed fluorescence. At the same time, the polycyclic compound of the embodiment represented by Formula 1 can be included as a dopant material of the emission layer EML. For example, the polycyclic compound of the embodiment represented by Formula 1 can be used as a TADF dopant.

[0141] Meanwhile, in the embodiment, the emission layer EML may include a known host material. For example, in the embodiment, the emission layer EML may include tris(8-hydroxyquinolinolato)aluminum (Alq 3 )、4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), poly(N-vinylcarbazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN), 4,4',4"-tri(carbazol-9-yl)-triphenylamine (TCTA), 1,3,5-tri(N-phenylbenzimidazol-2-yl)benzene (TPBi), 3-tert-butyl-9,10-di(naphthalene-2-yl)anthracene (TBADN ), distyrylarylene (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl (CDBP), 2-methyl-9,10-bis(naphthalene-2-yl)anthracene (MADN), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO 3 ), octaphenylcyclotetrasiloxane (DPSiO 4 ), 2,8-bis(diphenylphosphoryl)dibenzofuran (PPF), etc. However, the embodiments of the present inventive concept are not limited thereto. Any known host material for emitting delayed fluorescence other than the suggested host material may be included.

[0142] Meanwhile, in the organic electroluminescent device 10 of the embodiment, the emission layer EML may further include a known dopant material. In the embodiment, the emission layer EML may include a styryl derivative (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]styrene (DPAVB) and N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalene-2-yl)vinyl)phenyl)-N-phenylaniline (N-BDAVBi)), perylene and its derivatives (e.g., 2,5,8,11-tetra-tert-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene), etc. as a dopant.

[0143] Reference again Figures 1 to 3 In the organic electroluminescent device 10 of the embodiment, an electron transport region ETR is provided on the emission layer EML. The electron transport region ETR may include at least one of a hole blocking layer HBL, an electron transport layer ETL, and an electron injection layer EIL. However, embodiments of the inventive concept are not limited thereto.

[0144] The electron transport region ETR may have a single layer formed using a single material, a single layer formed using a plurality of different materials, or a multilayer structure having a plurality of layers formed using a plurality of different materials.

[0145] For example, the electron transport region ETR may have a single-layer structure of an electron injection layer EIL or an electron transport layer ETL, or a single-layer structure formed using an electron injection material and an electron transport material. In addition, the electron transport region ETR may have a single-layer structure containing a plurality of different materials, or a structure of an electron transport layer ETL / electron injection layer EIL, or a hole blocking layer HBL / electron transport layer ETL / electron injection layer EIL laminated from the first electrode EL1, without limitation. The thickness of the electron transport region ETR may be, for example, about 100 Å. to about

[0146] The electron transport region ETR may be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB), inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0147] If the electron transport region ETR includes an electron transport layer ETL, the electron transport region ETR may include, for example, tris(8-hydroxyquinolinolato)aluminum (Alq 3), 1,3,5-tris[(3-pyridyl)-phenyl-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 3-(4-biphenyl)-4-phenyl-5- One or more than one of tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-ato)aluminum (BAlq), bis(benzoquinolin-10-ato)beryllium (Bebq2), 9,10-di(naphthalene-2-yl)anthracene (ADN) or a mixture thereof, without limitation.

[0148] If the electron transport region ETR includes an electron transport layer ETL, the thickness of the electron transport layer ETL may be about 100 Å. to about and can be, for example, about to about If the thickness of the electron transport layer ETL satisfies the above range, satisfactory electron transport properties may be obtained without a significant increase in driving voltage.

[0149] If the electron transport region ETR includes the electron injection layer EIL, the electron transport region ETR may include, for example, LiF, lithium quinolate (LiQ), Li 2 O, BaO, NaCl, CsF, lanthanide metals (e.g., Yb) or metal halides (e.g., RbCl, RbI and KI). However, the embodiments of the present inventive concept are not limited thereto. A mixture material of an electron injection material and an insulating organic metal salt may also be used to form the electron injection layer EIL. The organic metal salt may be a material having an energy band gap of about 4 eV or greater than 4 eV. In particular, the organic metal salt may include, for example, metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates or metal stearates.

[0150] If the electron transport region ETR includes an electron injection layer EIL, the thickness of the electron injection layer EIL may be about 100 Å. to about For example, about to about If the thickness of the electron injection layer EIL satisfies the above range, satisfactory electron injection properties can be obtained without causing a significant increase in driving voltage.

[0151] The electron transport region ETR may include a hole blocking layer as described above. The hole blocking layer may include, for example, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and 4,7-diphenyl-1,10-phenanthroline (Bphen). However, embodiments of the inventive concept are not limited thereto.

[0152] A second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 has electrical conductivity. The second electrode EL2 may be formed using a metal alloy or a conductive compound. The second electrode EL2 may be a cathode. The second electrode EL2 may be a transmissive electrode, a semi-transmissive reflective electrode, or a reflective electrode. If the second electrode EL2 is a transmissive electrode, the second electrode EL2 may include a transparent metal oxide, for example, ITO, IZO, ZnO, ITZO, etc.

[0153] If the second electrode EL2 is a semi-transmissive reflective electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound thereof or a mixture thereof (e.g., a mixture of Ag and Mg). The second electrode EL2 may have a multilayer structure including a reflective layer or a semi-transmissive reflective layer formed using the above materials and a transparent conductive layer formed using ITO, IZO, ZnO, ITZO, etc.

[0154] Although not shown, the second electrode EL2 may be connected to the auxiliary electrode. If the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0155] In the organic electroluminescent device 10, holes injected from the first electrode EL1 may move to the emission layer EML via the hole transport region HTR, and electrons injected from the second electrode EL2 may move to the emission layer EML via the electron transport region ETR, according to a voltage applied to each of the first electrode EL1 and the second electrode EL2. The electrons and holes are recombined in the emission layer EML to generate excitons, and the excitons may emit light via transition from an excited state to a ground state.

[0156] If the organic electroluminescent device 10 is a top emission type, the first electrode EL1 may be a reflective electrode, and the second electrode EL2 may be a transmissive electrode or a semi-transmissive reflective electrode. If the organic electroluminescent device 10 is a bottom emission type, the first electrode EL1 may be a transmissive electrode or a semi-transmissive reflective electrode, and the second electrode EL2 may be a reflective electrode.

[0157] The organic electroluminescent device according to an embodiment of the present inventive concept uses the polycyclic compound as a material for an emission layer and may have improved emission efficiency and lifespan characteristics.

[0158] Embodiments of the present inventive concept provide a polycyclic compound represented by the following Formula 1:

[0159] [Formula 1]

[0160]

[0161] In formula 1, X 1 To X 10 Each of may independently be carbon or nitrogen.

[0162] In formula 1, R 1 To R 5 Each of may independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted amine group, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring.

[0163] R 1 To R 5 All of them do not include alkyl groups, especially cyclic alkyl groups. If R 1 To R 5 Including an alkyl group may reduce molecular stability, and if applied in a device, the half width of the emission layer is reduced to about 30 nm or less, and the rate of reverse intersystem crossing (RISC) for converting the triplet energy level (T1) to the singlet energy level (S1) may be deteriorated.

[0164] In Formula 1, each of "a" and "b" is independently an integer of 0 to 4. Meanwhile, if "a" is 2 or more, the plurality of R 1 The groups are the same or different, and if "b" is 2 or more, then multiple R 2 The groups are the same or different.

[0165] In Formula 1, "c" is an integer from 0 to 3. Meanwhile, if "c" is 2 or more, the plurality of R 3 The groups are the same or different.

[0166] In Formula 1, each of "d" and "e" is independently an integer from 0 to 5. If "d" is 2 or more, then the plurality of R 4 The groups are the same or different, and if "e" is 2 or more, then multiple R 5 The groups are the same or different.

[0167] In formula 1, if all X 1 To X 10 If both are carbon, then R 4 and R 5 At least one of is a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring. In this case, "d" and "e" are not 0 at the same time.

[0168] The same explanation of the polycyclic compound in the organic electroluminescent device of the embodiment can be applied to the polycyclic compound of the embodiment represented by Formula 1.

[0169] The polycyclic compound according to the embodiment may be any one selected from the compounds represented in Compound Group 1 above.

[0170] The polycyclic compound according to the embodiment may be any one selected from the compounds represented in Compound Group 2 above.

[0171] Hereinafter, the inventive concept will be explained in more detail with reference to specific embodiments and comparative embodiments.The following embodiments are merely examples to help understand the inventive concept, and the scope of the inventive concept is not limited thereto.

[0172] [Example]

[0173] 1. Synthesis of polycyclic compounds

[0174] First, the synthesis method of the polycyclic compound according to the exemplary embodiment of the present invention will be specifically explained with reference to the synthesis method of compound A-1, compound A-2 and compound A-3. In addition, the synthesis method of the polycyclic compound explained below is only an embodiment, and the synthesis method of the polycyclic compound according to the embodiment of the present invention is not limited thereto.

[0175] (Synthesis Example of Compound A-1)

[0176] The polycyclic compound (Compound A-1) according to the embodiment can be synthesized according to the following reaction:

[0177]

[0178] The o-dichlorobenzene solution (300 ml) containing 3-nitroaniline (25 g), iodobenzene (81.2 g), potassium carbonate (150 g) and cuprous iodide (6.9 g) was heated and refluxed for about 8 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 51.0 g (yield 97%) of intermediate 1.

[0179] A mixture solution of ethanol (120 ml) and water (60 ml) containing the intermediate 1 (51 g) thus obtained, iron (30 g) and ammonium chloride (29 g) was heated in an oil bath under heating conditions and refluxed for about 4 hours. The reaction solution was cooled to room temperature and filtered, and ethanol was distilled off. The target product was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 42.5 g (yield 93%) of intermediate 2.

[0180] The intermediate 2 (42.5 g) thus obtained, bromobenzene (25.2 g), sodium butoxide (31 g), Pd 2 (dba) 3 (2.1g) and PH(tBu) 3 / BF 4 The toluene solution (570ml) of (2.6g) was heated in an oil bath under heating conditions and refluxed for about 3 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 52g (yield 95%) of intermediate 3.

[0181] The intermediate 3 (52 g) thus obtained, 1-bromo-2,3-dichlorobenzene (34.9 g), sodium butoxide (34 g), Pd 2 (dba) 3 (3.2g) and PH(tBu) 3 / BF 4 The toluene solution (350ml) of (4.1g) was heated in an oil bath under heating conditions and refluxed for about 3 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 67g (yield 90%) of intermediate 4.

[0182] The intermediate 4 (6.7 g) thus obtained, 3-aminobiphenyl (2.3 g), sodium butoxide (2.4 g), Pd 2 (dba) 3 (0.22g) and PH(tBu) 3 / BF 4 The toluene solution (50 ml) of (0.29 g) was heated in an oil bath under heating conditions and refluxed for about 4 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 7.7 g (yield 90%) of intermediate 5.

[0183] The DMF solution (75ml) containing the intermediate 5 (7.7g) thus obtained and NaH (0.7g) was cooled in ice. Benzyl bromide (2.1ml) was added thereto and then stirred in ice for about 2 hours. After ensuring the disappearance of the raw material by TLC, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 7.7g (yield 69%) of intermediate 6.

[0184] The tert-butylbenzene solution (60 ml) containing the intermediate 6 (7.7 g) thus obtained was cooled to about -78°C. t-BuLi / pentane solution (13.8 ml) was added thereto, followed by stirring at about 60°C for about 2 hours. Then, the solution was cooled to about -35°C, and 1M BBr 3 Heptane solution (22ml) was added dropwise thereto, and then stirred at room temperature for about 3 hours. In addition, the solution was cooled to about -40 ° C, and diisopropylethylamine (3.8ml) was added dropwise thereto, and then heated at about 165 ° C and stirred for about 8 hours. The reaction mixture was returned to room temperature, and then poured into an aqueous sodium bicarbonate solution. The target material was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 1.5g (yield 20%) of intermediate 7.

[0185] The dichloromethane solution (30ml) containing the intermediate 7 (1.5g) thus obtained is cooled in ice. 1-Chloroethyl chloroformate (0.4ml) is added dropwise thereto, then stirred at room temperature for about 2 hours. After ensuring that the starting material disappears, the solvent is distilled out. MeOH (30ml) is added thereto, then heated and refluxed for about 1 hour. The mixture thus obtained is separated by silica gel column chromatography, to obtain 0.5g (yield 58%) of intermediate 8.

[0186] The intermediate 8 thus obtained (0.5 g), the intermediate 10 prepared separately (0.3 g), sodium butoxide (0.2 g), Pd 2 (dba) 3 (0.02g) and PH(tBu) 3 / BF 4The toluene solution (10ml) of (0.03g) was heated in an oil bath under heating conditions and refluxed for about 4 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 0.56g (yield 80%) of target product A-1. In addition, the molecular weight of the target product was found to be 817 by FAB-MS measurement. The compound A-1 thus obtained was separated by sublimation and used as a sample for evaluation.

[0187] (Synthesis Example of Compound A-2)

[0188] The polycyclic compound (Compound A-2) according to the embodiment can be synthesized according to the following reaction:

[0189]

[0190] The same procedures as in the method for synthesizing Compound A-1 were performed until Intermediate 2 was prepared.

[0191] 4-Methoxybenzyl bromide (37.1 g) and DIPEA (25.8 g) were added to an acetonitrile solution (500 ml) containing intermediate 2 (40 g), and then heated and refluxed for about 1 hour in an oil bath under heating conditions. The reaction solution was cooled to room temperature and poured into water. The target material was extracted with dichloromethane, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 47 g (yield 80%) of intermediate 3.

[0192] The intermediate 3 (47 g) thus obtained, 1-bromo-2,3-dichlorobenzene (29.3 g), sodium butoxide (17.8 g), Pd 2 (dba) 3 (3.2g) and PH(tBu) 3 / BF 4 The toluene solution (350ml) of (4.1g) was heated in an oil bath under heating conditions and refluxed for about 3 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 58g (yield 90%) of intermediate 4.

[0193] The intermediate 4 (7.3 g) thus obtained, 3-aminobiphenyl (2.3 g), sodium butoxide (2.4 g), Pd 2 (dba) 3 (0.22g) and PH(tBu) 3 / BF 4The toluene solution (50 ml) of (0.29 g) was heated in an oil bath under heating conditions and refluxed for about 4 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 8.2 g (yield 90%) of intermediate 5.

[0194] The DMF solution (75ml) containing the intermediate 5 (8.2g) thus obtained and NaH (0.7g) was cooled in ice. Benzyl bromide (2.1ml) was added thereto, and then stirred in ice for about 2 hours. After ensuring the disappearance of the raw material by TLC, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 7g (yield 75%) of intermediate 6.

[0195] The tert-butylbenzene solution (60 ml) containing the intermediate 6 (7 g) thus obtained was cooled to about -78°C. t-BuLi / pentane solution (13.8 ml) was added thereto, followed by stirring at about 60°C for about 2 hours. Then, the solution was cooled to about -35°C, and 1M BBr 3 Heptane solution (22ml) was added dropwise thereto, and then stirred at room temperature for about 3 hours. In addition, the solution was cooled to about -40 ° C, and diisopropylethylamine (3.8ml) was added dropwise thereto, and then heated at about 165 ° C and stirred for about 8 hours. The reaction mixture was returned to room temperature, and then poured into a sodium bicarbonate aqueous solution. The target material was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 1.9g (yield 28%) of intermediate 7.

[0196] The mixture solution (30 ml) of dichloromethane-water (20: 1) containing the intermediate 7 (1.9 g) thus obtained was cooled in ice. DDQ (1.1 equivalents) was added thereto, and then stirred at room temperature for about 2 hours. After ensuring that the raw materials disappeared, the reaction solution was poured into water. The target material was extracted with dichloromethane, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 1.35 g (yield 85%) of the intermediate 8 of the target material.

[0197] The intermediate 8 thus obtained (1.35 g), 4-(3-iodophenyl)pyridine (0.76 g), sodium butoxide (0.33 g), Pd 2 (dba) 3 (0.04g) and PH(tBu) 3 / BF 4The toluene solution (20 ml) of (0.06 g) was heated in an oil bath under heating conditions and refluxed for about 4 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 1.36 g (yield 80%) of intermediate 9 as the target material.

[0198] The dichloromethane solution (30ml) comprising the intermediate 9 (1.36g) thus obtained is cooled in ice, and 1-chloroethyl chloroformate (0.4ml) is added dropwise thereto. After stirring at room temperature for about 2 hours, ensure that the raw material disappears, and distill out the solvent. MeOH (30ml) is added thereto, then heated and refluxed for about 1 hour. The mixture thus obtained is separated by silica gel column chromatography, to obtain the intermediate 10 of 0.84g (productivity 70%).

[0199] The intermediate 10 thus obtained (0.84 g), the intermediate 11 prepared separately (0.54 g), sodium butoxide (0.2 g), Pd 2 (dba) 3 (0.02g) and PH(tBu) 3 / BF 4 The toluene solution (10ml) of (0.03g) was heated in an oil bath under heating conditions and refluxed for about 4 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 0.86g (yield 76%) of target material A-2. In addition, the molecular weight of the target material was found to be 893 by FAB-MS measurement. The compound A-2 thus obtained was separated by sublimation and used as a sample for evaluation.

[0200] Furthermore, from the emission spectrum measurement of the device, the half width of compound A-2 was assumed to be about 65 nm.

[0201] (Synthesis Example of Compound A-3)

[0202] The polycyclic compound (Compound A-3) according to the embodiment can be synthesized according to the following reaction:

[0203]

[0204] The same procedures as in the method for synthesizing Compound A-1 were performed until Intermediate 3 was prepared.

[0205] The intermediate 3 (52 g) thus obtained, 1-bromo-2,3-dichlorobenzene (47 g), sodium butoxide (34 g), Pd 2(dba) 3 (3.2g) and PH(tBu) 3 / BF 4 The toluene solution (350ml) of (4.1g) was heated in an oil bath under heating conditions and refluxed for about 3 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 78g (yield 90%) of intermediate 4.

[0206] The intermediate 4 (7.8 g) thus obtained, 3-aminobiphenyl (2.3 g), sodium butoxide (2.4 g), Pd 2 (dba) 3 (0.22g) and PH(tBu) 3 / BF 4 The toluene solution (50 ml) of (0.29 g) was heated in an oil bath under heating conditions and refluxed for about 4 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 8.2 g (yield 85%) of intermediate 5.

[0207] The DMF solution (75ml) containing the intermediate 5 (8.2g) thus obtained and NaH (0.7g) was cooled in ice. Benzyl bromide (2ml) was added thereto and then stirred in ice for about 2 hours. After ensuring the disappearance of the raw material by TLC, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 6.5g (yield 70%) of intermediate 6.

[0208] The tert-butylbenzene solution (60 ml) containing the intermediate 6 (6.5 g) thus obtained was cooled to about -78°C. t-BuLi / pentane solution (13.8 ml) was added thereto, followed by stirring at about 60°C for about 2 hours. Then, the solution was cooled to about -35°C, and 1M BBr 3 Heptane solution (22ml) was added dropwise thereto, and then stirred at room temperature for about 3 hours. In addition, the solution was cooled to about -40 ° C, and diisopropylethylamine (3.8ml) was added dropwise thereto, and then heated at about 165 ° C and stirred for about 8 hours. The reaction mixture was returned to room temperature, and then poured into a sodium bicarbonate aqueous solution. The target material was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 1.6g (yield 25%) of intermediate 7.

[0209] The dichloromethane solution (30ml) containing the intermediate 7 (1.6g) thus obtained is cooled in ice. 1-Chloroethyl chloroformate (0.4ml) is added dropwise thereto, then stirred at room temperature for about 2 hours. After ensuring that the starting material disappears, the solvent is distilled out. MeOH (30ml) is added thereto, then heated and refluxed for about 1 hour. The mixture thus obtained is separated by silica gel column chromatography, to obtain 0.9g (yield 65%) of intermediate 8.

[0210] The intermediate 8 thus obtained (0.9 g), the intermediate 9 prepared separately (0.3 g), sodium butoxide (0.2 g), Pd 2 (dba) 3 (0.02g) and PH(tBu) 3 / BF 4 The toluene solution (10ml) of (0.03g) was heated in an oil bath under heating conditions and refluxed for about 4 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with ethyl acetate, dried over magnesium sulfate and concentrated under reduced pressure. The mixture thus obtained was separated by silica gel column chromatography to obtain 0.91g (yield 75%) of target material A-3. In addition, the molecular weight of the target material was found to be 892 by FAB-MS measurement. The compound thus obtained was separated by sublimation and used as a sample for evaluation.

[0211] Furthermore, from the emission spectrum measurement of the device, the half width of compound A-3 was assumed to be about 58 nm.

[0212] 2. Fabrication and evaluation of organic electroluminescent devices containing polycyclic compounds

[0213] (Manufacturing of organic electroluminescent device)

[0214] The organic electroluminescent device of the exemplary embodiment containing the polycyclic compound of the exemplary embodiment in the emission layer was manufactured by the method described below. The polycyclic compounds of Compound A-1, Compound A-2 and Compound A-3 were used as materials for the emission layer to manufacture the organic electroluminescent devices of Examples 1 to 3. The compounds used in the emission layers in Examples 1 to 3 and Comparative Examples 1 to 5 are shown below.

[0215] [Exemplary compounds]

[0216]

[0217] [Comparative Compounds]

[0218]

[0219] The organic electroluminescent devices of Examples and Comparative Examples were manufactured by the method described below.

[0220] On a glass substrate, there will be approximately The ITO patterned with a thickness of 1000 mm was washed with ultrapure water and subjected to UV ozone treatment for about 10 minutes. Then, HAT-CN was deposited to about 1000 mm. The thickness of α-NPD was deposited to about The thickness of mCP was deposited to about to form a hole transport region.

[0221] Then, each of the polycyclic compound of the embodiment and the comparative compound was co-deposited with DPEPO at a ratio of 6:94 to form an emission layer to about Then, DPEPO was used to form a That is, in order to form an emission layer by co-deposition, each of Compound A-1, Compound A-2 and Compound A-3 was mixed with DPEPO and deposited in Examples 1 to 3, and each of Comparative Compound X-1, Comparative Compound X-2, Comparative Compound X-3, Comparative Compound X-4 and Comparative Compound X-5 was mixed with DPEPO and deposited in Comparative Examples 1 to 5.

[0222] On the emission layer, TPBi was used to form a layer of about The thickness of the LiF layer is about Then, a second electrode is formed using aluminum (Al) to a thickness of about Thickness.

[0223] In an embodiment, the hole transport region, the emission layer, the electron transport region, and the second electrode are formed by using a vacuum deposition apparatus.

[0224] (Evaluation of properties of organic electroluminescent devices)

[0225] In order to evaluate the properties of the organic electroluminescent devices of Examples and Comparative Examples, the maximum emission wavelength (nm) and the external quantum yield (%) were evaluated. The measurement was performed using a light emission brightness measurement device C9920-11 manufactured by HAMAMATSU Photonics Co.

[0226] [Table 1]

[0227] Grouping Emitting layer dopant Half Width <![CDATA[k RTSC (s -1 )]]> Device life Example 1 A-1 55nm <![CDATA[5.1×10 4 ]]> 147％ Example 2 A-2 65nm <![CDATA[4.3×10 4 ]]> 138％ Example 3 A-3 58nm <![CDATA[3.9×10 4 ]]> 135％ Comparative Example 1 Comparative Compound X-1 28nm <![CDATA[9.9×10 3 ]]> 100％ Comparative Example 2 Comparative Compound X-2 28nm <![CDATA[1.4×10 4 ]]> 118％ Comparative Example 3 Comparative Compound X-3 40nm <![CDATA[8.5×10 3 ]]> 93％ Comparative Example 4 Comparative Compound X-4 23nm <![CDATA[2.8×10 4 ]]> 128％ Comparative Example 5 Comparative Compound X-5 30nm <![CDATA[3.5×10 4 ]]> 120％

[0228] Referring to Table 1, when compared with Comparative Examples 1 to 5, the organic electroluminescent devices of Examples 1 to 3 using the polycyclic compound of the embodiment as the dopant material of the emission layer exhibited a larger RISC rate constant (k RTSC ). In addition, it was found that the organic electroluminescent devices of Examples 1 to 3 using the polycyclic compound of the embodiment as a dopant material for the emission layer exhibited increased device lifespan when compared to Comparative Examples 1 to 5.

[0229] It is found that the polycyclic compound of the embodiment has a half width of about 30nm to about 100nm, preferably about 50nm to about 70nm, and has a charge separation structure of HOMO-LUMO in the molecule. Therefore, the RISC rate increases and the life of the device increases, and therefore, the polycyclic compound can be used as a material for thermally activated delayed fluorescence.

[0230] The organic electroluminescent device of the embodiment includes the polycyclic compound of the embodiment in the emission layer, and can improve the half width and the RISC rate constant (k RTSC ), thereby increasing the life of the device.

[0231] When compared with the embodiment, the comparative compound X-1 and the comparative compound X-2 do not include the bonding shape of the electron donor and the electron acceptor. Therefore, the organic electroluminescent devices of the comparative examples 1 and 2 have smaller half width and RISC rate constant (k RTSC ), and the life of the device is relatively low.

[0232] Comparative compound X-3 used in Comparative Example 3 includes a pyridine group as an electron acceptor, but the organic electroluminescent device of Comparative Example 3 shows lower external quantum efficiency than that of Examples. This is considered to be because Comparative compound X-3 includes an electron donor including OBO, and therefore, the multiple resonance effect and delocalization occurring in the molecule are not well achieved.

[0233] The comparative compound X-4 used in Comparative Example 4 has a fused shape formed by three rings and NB, and the organic electroluminescent device of Comparative Example 4 has a smaller half width and RISC rate constant (k RTSC ), and therefore, the life of the device is relatively low.

[0234] In addition, when compared with the examples, the organic electroluminescent device of Comparative Example 5 has a smaller half width and RISC rate constant (k RTSC ), and therefore, the lifetime of the device is relatively low. It is considered that the comparative compound X-5 used in Comparative Example 5 contains a cyclic alkyl group as a substituent, and delocalization of electrons in the molecule is not well achieved.

[0235] Organic electroluminescent devices according to embodiments of the inventive concept may achieve high efficiency and a long lifespan.

[0236] The polycyclic compound according to an embodiment of the inventive concept may improve the lifespan and efficiency of an organic electroluminescent device.

[0237] Although exemplary embodiments of the present invention have been described, it should be understood that the present invention should not be limited to these exemplary embodiments, but various changes and modifications may be made by one of ordinary skill in the art within the spirit and scope of the claimed invention.

Claims

1. A polycyclic compound represented by the following formula 2: [Formula 2] In formula 2, Ar1 and Ar2 are each independently an aryl group having 6 to 30 carbon atoms for forming a ring, or a heteroaryl group having 2 to 30 carbon atoms for forming a ring, X1 to X5 are each independently carbon or nitrogen, and all of X1 to X5 are carbon or two of X1 to X5 are nitrogen, X6 to X 10 For carbon, R1 to R5 are each independently an aryl group having 6 to 30 carbon atoms for forming a ring, or a heteroaryl group having 2 to 30 carbon atoms for forming a ring, a is 0 or 1, c is 0 or 1, d is an integer from 0 to 2, e is 0 or 1, and f is 0, If all X1 to X 10 If both are carbon, then d is 2 and at least one of the two R4 is a pyridine group and the rest are phenyl groups.

2. The polycyclic compound as claimed in claim 1, wherein X1 to X5 are carbon.

3. The polycyclic compound as claimed in claim 2, wherein two R4 are pyridine groups. The polycyclic compound as claimed in claim 1 , wherein R 1 is a phenyl group. The polycyclic compound according to claim 1 , wherein R 5 is phenyl or pyridyl.

6. The polycyclic compound according to claim 1, wherein the compound represented by Formula 2 is any one of the compounds represented in the following compound group 1: [Compound Group 1] 7. The polycyclic compound according to claim 1, wherein the compound represented by Formula 2 is any one of the compounds represented in the following Compound Group 2: [Compound Group 2] 8. An organic electroluminescent device comprising: a first electrode; a hole transport region disposed on the first electrode; an emission layer disposed on the hole transport region; an electron transport region disposed on the emission layer; and a second electrode disposed on the electron transport region, wherein the first electrode and the second electrode each independently include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, In, Sn, Zn, a compound selected from two or more thereof, a mixture selected from two or more thereof, or a transparent metal oxide, and The emission layer comprises the polycyclic compound according to any one of claims 1 to 7.

9. The organic electroluminescent device according to claim 8, wherein the emission layer is a delayed fluorescent emission layer comprising a host and a dopant, and The dopant is the polycyclic compound. 10 . The organic electroluminescent device according to claim 8 , wherein the emission layer is a thermally activated delayed fluorescent emission layer that emits blue light.

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