Organic electroluminescent device and polycyclic compound for organic electroluminescent device

Abstract

An organic electroluminescent device of an embodiment and a polycyclic compound for an organic electroluminescent device are provided. The organic electroluminescent device includes a first electrode, a second electrode, and a plurality of organic layers arranged between the first electrode and the second electrode, wherein at least one of the organic layers includes a polycyclic compound, the polycyclic compound includes a plurality of electron donors and electron acceptors connected to the electron donors, at least one of the electron donors is a condensed ring including a boroheptene nucleus, and the electron acceptor includes a phenyl group or a heteroaryl group, the phenyl group includes at least one cyano group or a heterocyclic ring including at least one nitrogen atom as a substituent, and the heteroaryl group includes an oxygen atom or a sulfur atom for forming a ring, thereby achieving improved emission efficiency.

Description

[0001] This patent application claims the benefit of Korean Patent Application No. 10-2018-0155179, filed on December 5, 2018, which is hereby incorporated by reference in its entirety. Technical Field

[0002] The present disclosure herein relates to an organic electroluminescent device and a polycyclic compound for use in the organic electroluminescent device. Background Art

[0003] Organic electroluminescent displays are being actively developed as image displays. The difference between an organic electroluminescent display and a liquid crystal display is that the organic electroluminescent display is a self-luminescent display that displays an image by causing holes and electrons injected from a first electrode and a second electrode to recombine in an emission layer. Light is emitted from a light-emitting material including an organic compound in the emission layer.

[0004] When organic electroluminescent devices are applied to displays, there is a need to reduce driving voltage, increase emission efficiency, and extend lifespan for the organic electroluminescent devices, and there is a constant need to develop materials that can reliably achieve the requirements for organic electroluminescent devices.

[0005] Specifically, in order to realize a highly efficient organic electroluminescent device, development of delayed fluorescence emission using triplet energy level phosphorescence emission or triplet-triplet annihilation (TTA) in which singlet excitons are generated by collision of triplet excitons is being conducted recently. In addition, thermally activated delayed fluorescence (TADF) materials utilizing the delayed fluorescence phenomenon are being developed. Summary of the invention

[0006] The present disclosure provides an organic electroluminescent device having improved emission efficiency and device lifespan.

[0007] The present disclosure also provides a polycyclic compound that can improve the emission efficiency and lifetime of an organic electroluminescent device.

[0008] Embodiments of the inventive concept provide a polycyclic compound represented by Formula 1 below.

[0009] [Formula 1]

[0010]

[0011] In Formula 1, DU1 and DU2 are represented by Formula 2-1 or Formula 2-2 below, at least one of DU1 and DU2 is represented by Formula 2-1 below, AU is represented by Formula 3-1 or Formula 3-2 below, and m is 1 or 2.

[0012] [Formula 2-1]

[0013]

[0014] [Formula 2-2]

[0015]

[0016] [Formula 3-1]

[0017]

[0018] [Formula 3-2]

[0019]

[0020] In formula 2-2, X 1 N or NR a , X 2 For direct connection key, CR b R c or (CR d )=(CR e ), n is an integer from 1 to 2.

[0021] In Formula 2-1 and Formula 2-2, Ar 1 To Ar 5 are each independently a hydrocarbon ring having 5 to 60 carbon atoms for forming a ring or a heterocyclic ring having 5 to 60 carbon atoms for forming a ring, the heterocyclic ring excluding a nitrogen atom for forming a ring, and a to e are each independently an integer of 0 to 4.

[0022] In formula 3-1, R w is a cyano group or a substituted or unsubstituted heterocyclic ring having 2 to 60 carbon atoms for forming a ring, the heterocyclic ring including at least one nitrogen atom for forming a ring, p is an integer of 1 to 3, and f is an integer of 0 to 3.

[0023] In formula 3-2, Y 1 O, S or SO 2 , Y 2 Direct key or CR f R g , g and h are each independently an integer from 0 to 3.

[0024] In Formula 2-1, Formula 2-2, Formula 3-1 and Formula 3-2, R 1 To R 8 and R a To R g Each is independently a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 5 to 30 carbon atoms for forming a ring.

[0025] In an embodiment, Formula 1 may be represented by the following Formula 1-1.

[0026] [Formula 1-1]

[0027]

[0028] In Formula 1-1, AU, DU2 and m are the same as those defined in Formula 1, and Ar 1 To Ar 3 , R 1 To R 3 and a to c are the same as defined in Formula 2-1.

[0029] In an embodiment, DU2 may be represented by any one of D1 to D3 below.

[0030]

[0031] In D1 to D3, R 1 To R 3 , a to c and R a The same as defined in Formula 2-1 and Formula 2-2.

[0032] In an embodiment, Formula 2-1 may be represented by the following Formula 2-1A.

[0033] [Formula 2-1A]

[0034]

[0035] In formula 2-1A, R 1 To R 3 and a to c are the same as defined in Formula 2-1.

[0036] In an embodiment, Formula 2-2 may be represented by the following Formula 2-2A or Formula 2-2B.

[0037] [Formula 2-2A]

[0038]

[0039] [Formula 2-2B]

[0040]

[0041] In Formula 2-2A and Formula 2-2B, Ar 4 ,Ar 5 , R 4 , R 5 , d, e, X 2 , n and R a Same as defined in Formula 2-2.

[0042] In an embodiment, AU may be represented by any one of A1 to A7 below.

[0043]

[0044] In A1 and A2, p is an integer of 1 to 3.

[0045] In the embodiment, Ar 1 To Ar 3 The benzene ring may be substituted or unsubstituted.

[0046] In an embodiment, R w It may be a cyano group or a substituted or unsubstituted triazine group.

[0047] In an embodiment of the inventive concept, an organic electroluminescent device includes: a first electrode; a second electrode disposed on the first electrode; and a plurality of organic layers disposed between the first electrode and the second electrode, wherein at least one of the organic layers includes a polycyclic compound, the polycyclic compound including a plurality of electron donors and electron acceptors connected to the electron donors, at least one of the electron donors is a condensed ring including a borahertz nucleus, and the electron acceptor includes a phenyl group or a heteroaryl group, the phenyl group includes at least one cyano group or a heterocycle containing at least one nitrogen atom as a substituent, and the heteroaryl group includes an oxygen atom or a sulfur atom for forming a ring.

[0048] In an embodiment, the organic layer may include a hole transport region; an emission layer disposed on the hole transport region; and an electron transport region disposed on the emission layer, and the emission layer may include the polycyclic compound.

[0049] In an embodiment, the emission layer may emit delayed fluorescence.

[0050] 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.

[0051] In an embodiment, the emissive layer may emit blue light.

[0052] In an embodiment, at least one of the electron donors may include a substituted or unsubstituted tribenzoborole.

[0053] In an embodiment, the electron acceptor can be a phenyl group including at least one cyano group as a substituent, a phenyl group including a substituted or unsubstituted triazine group as a substituent, a substituted or unsubstituted xanthene group, a substituted or unsubstituted thioxanthenyl group, a substituted or unsubstituted dibenzothiodioxyphenyl group, or a substituted or unsubstituted thioxanthenyl group.

[0054] In an embodiment, the organic layer may be disposed by an inkjet process.

[0055] In an embodiment, the polycyclic compound may be represented by Formula 1.

[0056] In an embodiment of the inventive concept, an organic electroluminescent device includes: a first electrode; a hole transport region disposed on the first electrode; an emission layer disposed on the hole transport region, the emission layer including a polycyclic compound represented by Formula 1; an electron transport region disposed on the emission layer; and a second electrode disposed on the electron transport region. The first electrode and the second electrode each independently include at least one selected from the following: Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, a compound selected from two or more thereof, a mixture selected from two or more thereof, and a transparent metal oxide, wherein the transparent metal oxide may include at least one selected from indium tin oxide, indium zinc oxide, zinc oxide, and indium tin zinc oxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The accompanying drawings are included to provide a further understanding of the inventive concept and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate exemplary embodiments of the inventive concept and together with the description are used to explain the principles of the inventive concept. In the drawings:

[0058] Figure 1 is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the inventive concept;

[0059] Figure 2 is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the inventive concept; and

[0060] Figure 3 is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the inventive concept. DETAILED DESCRIPTION

[0061] The inventive concept may have various modifications and may be implemented in different forms, and example embodiments will be explained in detail with reference to the accompanying drawings. However, the inventive concept should not be interpreted as being limited to the embodiments set forth herein. On the contrary, it should be understood that the scope of the inventive concept includes all modifications, equivalents, and substitutions within the spirit and scope of the inventive concept as hereinafter claimed.

[0062] In the present disclosure, it will be understood that when an element (or region, layer, portion, etc.) is referred to as being "on," "connected to" or "coupled to" another element, it can be directly on / connected to / coupled to the other element, or intervening elements may be present.

[0063] For explaining each of the drawings, the same reference numerals refer to the same elements. In the drawings, the thickness, proportion and size of the elements are exaggerated for effective description of the technical contents.

[0064] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0065] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first element discussed below may be named as the second element, and similarly, the second element may be named as the first element. As used herein, unless the context clearly states otherwise, the singular form is also intended to include the plural form.

[0066] Spatially relative terms such as "under", "below", "above", "on", etc. are used herein to describe the relationship of one element or feature to another (additional) element or feature as shown in the drawings. It will be understood that the spatially relative terms are relative concepts described based on the orientations depicted in the drawings.

[0067] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention belongs. It will also be understood that terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense, unless explicitly defined as such herein.

[0068] It will be understood that when the terms “including” or “having” are used in this specification, it indicates the presence of the stated features, numbers, steps, operations, elements, parts or combinations thereof, but does not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, parts or combinations thereof.

[0069] Hereinafter, an organic electroluminescent device according to an embodiment of the inventive concept and a polycyclic compound included therein according to an embodiment of the inventive concept will be explained with reference to the accompanying drawings.

[0070] Figures 1 to 3 Each of the diagrams is a schematic cross-sectional view showing an organic electroluminescent device according to an embodiment of the inventive concept. Figures 1 to 3In the organic electroluminescent device 10 of the embodiment, 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. That is, the organic electroluminescent device 10 of 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 stacked in sequence. At the same time, at least one of the plurality of organic layers may be arranged by an inkjet process. For example, organic layers such as the hole transport region HTR, the emission layer EML, and the electron transport region ETR may be formed by an inkjet process.

[0071] The organic electroluminescent device 10 of the embodiment according to the inventive concept may include the polycyclic compound of the embodiment according to the inventive concept in at least one of the plurality of organic layers disposed between the first electrode EL1 and the second electrode EL2. For example, the organic electroluminescent device 10 of the embodiment may include the polycyclic compound of the embodiment in at least one organic layer of the hole transport region HTR, the emission layer EML, and the electron transport region ETR. Specifically, the organic electroluminescent device 10 of the embodiment may include the polycyclic compound of the embodiment as a light-emitting material in the emission layer EML.

[0072] Figure 2 A schematic cross-sectional view of an organic electroluminescent device 10 according to an embodiment of the inventive concept 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 compared to, Figure 3 A schematic cross-sectional view of an organic electroluminescent device 10 according to an embodiment of the inventive concept 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.

[0073] The first electrode EL1 has conductivity. The first electrode EL1 may be formed of a metal alloy or a conductive compound. The first electrode EL1 may be an anode. The first electrode EL1 may also be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a transflective electrode or a reflective electrode. In the case where the first electrode EL1 is a transmissive electrode, the first electrode EL1 may include a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO) or indium tin zinc oxide (ITZO). In the case where the first electrode EL1 is a transflective electrode or a reflective electrode, the first electrode EL1 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, a composite 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 transflective layer formed using the above materials and a transparent conductive layer formed using ITO, IZO, ZnO or ITZO. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO. However, embodiments of the inventive concept are not limited thereto. The thickness of the first electrode EL1 may be about 100 Å. to about For example, about to about

[0074] The hole transport region HTR is disposed 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 (not shown), and an electron blocking layer EBL. The thickness of the hole transport region HTR may be, for example, about 100 Å. to about

[0075] 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.

[0076] 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. In addition, the hole transport region HTR may have a single-layer structure formed using a plurality of different materials, or a stacked structure of a hole injection layer HIL / hole transport layer HTL, a hole injection layer HIL / hole transport layer HTL / hole buffer layer (not shown), a hole injection layer HIL / hole buffer layer (not shown), a hole transport layer HTL / hole buffer layer, or a hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL stacked in sequence from the first electrode EL1 without limitation.

[0077] The hole transport region HTR may be formed using various methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and a laser induced thermal imaging (LITI) method.

[0078] The hole injection layer HIL may include a phthalocyanine compound such as copper phthalocyanine; N,N'-diphenyl-N,N'-bis-[4-(di(m-tolyl)-amino)-phenyl]-biphenyl-4,4'-diamine (DNTPD), 4,4',4"-tris[(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4"-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tris[N-(2-naphthyl)-N-phenylamino]-triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-phenylene)triphenylamine (PTTA), Sulfonate) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphorsulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium-tetrakis(pentafluorophenyl)borate, dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexanitrile (HAT-CN), etc.

[0079] The hole transport layer HTL may also include carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, fluorene derivatives, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), triphenylamine derivatives such as 4,4',4"-tri(N-carbazolyl)triphenylamine (TCTA), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB), 4,4'-cyclohexylene-bis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl (HMTPD), 1,3-bis(N-carbazolyl)benzene (mCP), and the like.

[0080] 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 The thickness of the hole transport layer HTL may be about to about For example, the thickness of the electron blocking layer EBL may be about to about In the case where 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 performance may be obtained without significantly increasing driving voltage.

[0081] 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, and a cyano-containing compound without limitation. For example, non-limiting examples of p-dopants may include quinone derivatives such as tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), metal oxides such as tungsten oxide and molybdenum oxide, without limitation.

[0082] 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 (not shown) and an electron blocking layer EBL. The hole buffer layer (not shown) may increase the luminous efficiency by compensating the optical resonance distance according to the wavelength of the light emitted from the emission layer EML. The material included in the hole transport region HTR may be used as the material included in the hole buffer layer (not shown). The electron blocking layer EBL is a layer that prevents electrons from being injected from the electron transport region ETR into the hole transport region HTR.

[0083] The emission layer EML is disposed on the hole transport region HTR. The thickness of the emission layer EML may be, for example, about to about or 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 multi-layer structure having a plurality of layers formed using a plurality of different materials.

[0084] In the organic electroluminescent device 10 according to an embodiment of the inventive concept, the emission layer EML may include a polycyclic compound according to an embodiment of the inventive concept.

[0085] The polycyclic compound of an embodiment according to the inventive concept may include a plurality of electron donors and an electron acceptor disposed between the electron donors. The electron acceptor may connect the electron donors to each other. The electron acceptor may be combined with a plurality of electron donors. For example, the polycyclic compound of the embodiment may include two electron donors and one electron acceptor, or may include three electron donors and one electron acceptor.

[0086] In the polycyclic compound of the embodiment, at least one of the electron donors may be a condensed ring including a borepine core. At least one of the electron donors may be a condensed ring including a borepine core and three hydrocarbon rings or heterocyclic rings condensed to the borepine core. At the same time, the heterocyclic ring condensed to the borepine core does not include a nitrogen atom. Specifically, at least one of the electron donors in the polycyclic compound of the embodiment may include substituted or unsubstituted tribenzoborone.

[0087] In the polycyclic compound of the embodiment, the electron donor may include a heteroaryl group including a nitrogen atom in addition to the condensed ring including the borane nucleus. For example, the electron donor of the polycyclic compound may include a substituted or unsubstituted carbazole group.

[0088] In the polycyclic compound of the embodiment, the electron acceptor may be a phenyl group including at least one cyano group or a heterocyclic ring having at least one nitrogen atom as a substituent. Alternatively, the electron acceptor in the polycyclic compound of the embodiment may be a heteroaryl group including an oxygen atom or a sulfur atom for forming a ring.

[0089] In the polycyclic compound of the embodiment, the electron acceptor may be a phenyl group including at least one cyano group as a substituent, a phenyl group including a substituted or unsubstituted triazine group as a substituent, a substituted or unsubstituted xanthene group, a substituted or unsubstituted thioxanthene group, a substituted or unsubstituted dibenzothiophene dioxide group (or dioxy-dibenzothiophene group), or a substituted or unsubstituted thioxanthene dioxide group (or dioxy-thioxanthene group).

[0090] For example, the electron acceptor may be a phenyl substituted with two cyano groups, a phenyl substituted with three cyano groups, a phenyl substituted with a diphenyltriazine group, a phenyl substituted with both a cyano group and a diphenyltriazine group, a dimethylxanthene group, a dibenzothiodioxythienyl group, or a dimethylthiodioxythioxanthene group (or dioxo-dimethylthioxanthene group). However, embodiments of the inventive concept are not limited thereto.

[0091] In the present disclosure, "substituted or unsubstituted" may mean unsubstituted or substituted with at least one substituent selected from the group consisting of deuterium, halogen, cyano, nitro, amino, silyl, oxy, sulfenyl, sulfonyl, carbonyl, boron, phosphine oxide, phosphine sulfide, alkyl, alkenyl, alkoxy, hydrocarbon ring, aryl and heterocyclic group. In addition, each substituent described above may be substituted or unsubstituted. For example, biphenyl may be interpreted as aryl, or phenyl substituted with phenyl.

[0092] In the present disclosure, the halogen atom is exemplified by a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0093] In the present disclosure, the alkyl group may have a linear, branched or cyclic form. 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-heneicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, n-triacontyl and the like without limitation.

[0094] In the present disclosure, hydrocarbon rings include aliphatic hydrocarbon rings and aromatic hydrocarbon rings. Heterocycles include aliphatic heterocycles and aromatic heterocycles. Hydrocarbon rings and heterocycles may be monocyclic or polycyclic.

[0095] In the present disclosure, the hydrocarbon ring may be any functional group or substituent derived from an aliphatic hydrocarbon ring, or any functional group or substituent derived from an aromatic hydrocarbon ring. The hydrocarbon ring may have 5 to 60 carbon atoms for forming the ring.

[0096] In the present disclosure, the heterocyclic ring may be any functional group or substituent derived from a heterocyclic ring including at least one heteroatom for forming a ring. The number of carbon atoms for forming the heterocyclic ring may be 5 to 60.

[0097] In the present disclosure, aryl refers to any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of carbon atoms in the aryl group used to form the ring may be 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups may include phenyl, naphthyl, fluorenyl, anthracenyl, phenanthrenyl, biphenyl, terphenyl, quaterphenyl, pentaphenyl, hexaphenyl, benzo[9,10]phenanthrenyl, pyrenyl, benzofluoranthenyl, Base, etc., without restriction.

[0098] In the present disclosure, the fluorenyl group may be substituted, and two substituents may be combined with each other to form a spiro structure. Examples of the substituted fluorenyl group may include the following groups without limitation.

[0099]

[0100] In the present disclosure, the heteroaryl group may be a heteroaryl group including at least one of B, O, N, P, Si and S as a heteroatom for ring formation. When the heteroaryl group includes two or more heteroatoms, these heteroatoms may be the same as or different from each other. The heteroaryl group may be a monocyclic heterocycle or a polycyclic heterocycle. The carbon number of the heteroaryl group for ring formation may be 2 to 30, 2 to 20 or 2 to 10. Examples of heteroaryl groups may include thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidyl, triazinyl, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolinyl, quinoxalinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, N-arylcarbazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothienyl, dibenzothienyl, thienothiphenyl, benzofuranyl, phenanthrolinyl, isoxazolyl, thiadiazolyl, phenothiazinyl, dibenzosilyl, dibenzofuranyl, and the like without limitation.

[0101] In the present disclosure, the above explanation about the aryl group may be applied to the arylene group except that the arylene group is divalent. The above explanation about the heteroaryl group may be applied to the heteroarylene group except that the heteroarylene group is divalent.

[0102] In the present disclosure, silyl groups include alkylsilyl groups and arylsilyl groups. Examples of silyl groups may include trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, etc., without limitation.

[0103] In the present disclosure, the carbon number of the amino group is not particularly limited, and may be 1 to 30. The amino group may include an alkylamino group and an arylamino group. Examples of the amino group include methylamino, dimethylamino, phenylamino, diphenylamino, naphthylamino, 9-methyl-anthrylamino, triphenylamino, etc., without limitation.

[0104] In the present disclosure, -* indicates a position to be connected. Meanwhile, in the present disclosure, ---* indicates a position to be connected which can be selectively adopted or deleted according to the number of binding sites.

[0105] Meanwhile, in the present disclosure, a dotted line (----) indicates a position to which a double bond may be selectively applied. That is, the position indicated by the dotted line (----) may be a position of a double bond or a single bond.

[0106] The polycyclic compound of the embodiment included in the organic electroluminescent device 10 of the embodiment may be represented by Formula 1 below.

[0107] [Formula 1]

[0108]

[0109] In Formula 1, DU1 and DU2 may be electron donors, and AU may be an electron acceptor. In Formula 1, m may be 1 or 2. That is, the polycyclic compound represented by Formula 1 may include two or more electron donors and an electron acceptor disposed between the electron donors.

[0110] In Formula 1, DU1 and DU2 may be the same as or different from each other. In the case where m is 2, the two moieties represented by DU2 may be the same as or different from each other.

[0111] In Formula 1, DU1 and DU2 may be represented by the following Formula 2-1 or Formula 2-2. In addition, at least one of DU1 and DU2 may be represented by the following Formula 2-1.

[0112] [Formula 2-1]

[0113]

[0114] [Formula 2-2]

[0115]

[0116] In Formula 2-1 and Formula 2-2, Ar 1 To Ar 5 Each may independently be a hydrocarbon ring having 5 to 60 carbon atoms for forming a ring, or a heterocyclic ring having 5 to 60 carbon atoms for forming a ring, the heterocyclic ring excluding a nitrogen atom for forming a ring.

[0117] In formula 2-1 and formula 2-2, R 1 To R 5 Each may independently be a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 5 to 30 carbon atoms for forming a ring.

[0118] In Formula 2-1 and Formula 2-2, a, b, c, d, and e may each independently be an integer of 0 to 4. In the case where a, b, c, d, or e is an integer of 2 or more, a plurality of R 1 , multiple R 2 , multiple R 3 , multiple R 4 And multiple R 5 Each of can be the same as or different from each other.

[0119] Formula 2-1 shows a borane nucleus In Formula 2-1, Ar 1 To Ar 3 can be the same or different from each other. For example, in Formula 2-1, Ar 1 To Ar 3 Specifically, in Formula 2-1, Ar 1 To Ar 3 It may be a substituted or unsubstituted benzene ring. For example, Formula 2-1 may be a substituted or unsubstituted tribenzoborole.

[0120] For example, Formula 2-1 can be represented by the following Formula 2-1A.

[0121] [Formula 2-1A]

[0122]

[0123] In Formula 2-1A, the same explanation as in Formula 2-1 can be applied to R 1 To R 3 and a to c.

[0124] In formula 2-2, X 1 Can be N or NR a , X 2 Can be direct linkage (also called single bond), CR b R c or (CR d )=(CR e ). In addition, n can be an integer from 1 to 2.

[0125] In formula 2-2, Ar 4 and Ar5 can be the same or different from each other. For example, in Formula 2-2, Ar 4 and Ar 5 Specifically, in Formula 2-2, Ar 4 and Ar 5 The benzene ring may be substituted or unsubstituted.

[0126] In formula 2-2, X 1 Can be N or NR a .

[0127] In formula 2-2, R a To R e and R are independently hydrogen atoms, deuterium atoms, halogen atoms, alkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 carbon atoms for forming a ring, or substituted or unsubstituted heteroaryl groups having 5 to 30 carbon atoms for forming a ring. a It may be an unsubstituted phenyl group.

[0128] For example, Formula 2-2 may be represented by the following Formula 2-2A or Formula 2-2B. Formula 2-2A differs from Formula 2-2B in the position at which the electron acceptor AU is attached.

[0129] [Formula 2-2A]

[0130]

[0131] [Formula 2-2B]

[0132]

[0133] In Formula 2-2A and Formula 2-2B, the same explanation as in Formula 2-2 can be applied to Ar 4 ,Ar 5 , R 4 , R 5 , d, e, X 2 , n and R a .

[0134] In formula 2-2, X 1 Can be N or NR a , X 2 Can be a direct key, Ar 4 and Ar 5 It may be a substituted or unsubstituted benzene ring. Specifically, Formula 2-2 may be a substituted or unsubstituted carbazole group. For example, Formula 2-2 may be represented by D2 or D3 below.

[0135]

[0136] In D3, the same explanation as in Formula 2-2 can be applied to R a .

[0137] In Formula 1, AU can be expressed by the following Formula 3-1 or Formula 3-2.

[0138] [Formula 3-1]

[0139]

[0140] [Formula 3-2]

[0141]

[0142] In formula 3-1, R w It may be a cyano group or a substituted or unsubstituted heterocyclic ring having 2 to 60 (e.g., 5 to 60) carbon atoms for forming a ring, the heterocyclic ring including at least one nitrogen atom for forming a ring. w It may be a cyano group or a substituted or unsubstituted triazine group.

[0143] In Formula 3-1, p may be an integer from 1 to 3. In Formula 3-1, when p is an integer of 2 or more, a plurality of R w Can include the same R w , or at least two may be different from each other.

[0144] In Formula 3-1, f may be an integer from 0 to 3. When f is an integer of 2 or more, a plurality of R 6 Can include the same R 6 , or at least two may be different from each other.

[0145] In formula 3-2, Y 1 Can be O, S or SO 2 That is, Formula 3-2 may be a heteroarylene group including an oxygen atom or a sulfur atom for forming a ring.

[0146] In formula 3-2, Y 2 Can be a direct key or CR f R g , g and h may each independently be an integer of 0 to 3. In Formula 3-2, when each of g and h is an integer of 2 or more, a plurality of R 7 and multiple R 8 Each of may be the same, or at least two may be different from each other.

[0147] In formula 3-1 and formula 3-2, R 6 To R 8 , R f and R gEach of may independently be a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms for forming a ring, or a substituted or unsubstituted heteroaryl group having 5 to 30 carbon atoms for forming a ring.

[0148] Meanwhile, Formula 3-1 may be represented by the following Formula 3-1A or Formula 3-1B. Formula 3-1A represents a divalent phenyl group, and Formula 3-1B represents a trivalent phenyl group. For example, the electron acceptor (AU) represented by Formula 3-1A may be combined with two electron donors, and the electron acceptor (AU) represented by Formula 3-1B may be combined with three electron donors.

[0149]

[0150] Formula 1 may be represented by the following Formula 1-1. That is, the polycyclic compound of the embodiment may include a condensed ring having a boraherpine core as an electron donor.

[0151] [Formula 1-1]

[0152]

[0153] In Formula 1-1, the same explanation as in Formula 1 may be applied to AU, DU2, and m. In addition, the same explanation as in Formula 2-1 may be applied to Ar 1 To Ar 3 , R 1 To R 3 and a to c.

[0154] In Formula 1-1, DU2 may be represented by any one of D1 to D3 below.

[0155]

[0156] In D1, the same explanation as in Formula 2-1 can be applied to R 1 To R 3 and a to c, the same explanation as in Formula 2-2 can be applied to R in D3 a .

[0157] In Formula 1-1, AU can be represented by any one of A1 to A7 below.

[0158]

[0159] In A1 and A2, p may be an integer from 1 to 3.

[0160] The polycyclic compound according to an embodiment of the inventive concept may be any one of the compounds represented in the following Compound Group 1.

[0161] [Compound Group 1]

[0162]

[0163]

[0164] The organic electroluminescent device 10 according to the embodiment of the inventive concept may include at least one of the compounds represented in compound group 1 in at least one organic layer. For example, the organic electroluminescent device 10 of the embodiment may include at least one of the polycyclic compounds represented in compound group 1 in the emission layer EML.

[0165] In the organic electroluminescent device 10 of the embodiment, the emission layer EML may emit delayed fluorescence. For example, the emission layer EML may emit thermally activated delayed fluorescence (TADF).

[0166] In the organic electroluminescent device 10, the emission layer EML may emit blue light. For example, in the organic electroluminescent device 10 of the embodiment, the emission layer EML may emit blue light having a wavelength range of about 480 nm or less. However, embodiments of the inventive concept are not limited thereto, and the emission layer EML may emit red light or green light.

[0167] Although not shown in the drawings, the organic electroluminescent device 10 of the embodiment may include a plurality of emission layers. The plurality of emission layers may be provided as stacked layers, and the organic electroluminescent device 10 including the plurality of emission layers may emit, for example, white light. The organic electroluminescent device 10 including the plurality of emission layers may be an organic electroluminescent device of a tandem structure.

[0168] In an embodiment, the emission layer EML may include a host and a dopant, and include the above-mentioned polycyclic compound as a dopant. For example, in the organic electroluminescent device 10 of the embodiment, the emission layer EML may include a host for delayed fluorescence emission and a dopant for delayed fluorescence emission, and include the above-mentioned polycyclic compound as a dopant for delayed fluorescence emission. The emission layer EML may include at least one of the compounds represented in the above-mentioned compound group 1 as a thermally activated delayed fluorescence dopant.

[0169] In an embodiment, the emission layer EML may be a delayed fluorescent emission layer and include a known host material and the above-mentioned polycyclic compound. For example, the polycyclic compound of the embodiment may be used as a TADF dopant.

[0170] In an embodiment, the emission layer EML may include a known host material. For example, the emission layer EML may include tris(8-hydroxyquinoline)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(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi), 2-tert-butyl-9,10-di(naphthalene-2-yl)anthracene (TBA DN), distyryl arylide (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), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (mCBP), 1,3-bis(N-carbazolyl)benzene (mCP), etc. as host materials. However, embodiments of the inventive concept are not limited thereto, and in addition to the above-mentioned host materials, known delayed fluorescence host materials may be included.

[0171] 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]stilbene (DPAVB), 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.

[0172] In such Figures 1 to 3 In the organic electroluminescent device 10 according to an embodiment of the inventive concept shown in FIG, an electron transport region ETR is disposed 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 without limitation.

[0173] 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 including a plurality of layers formed using a plurality of different materials.

[0174] 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 including a plurality of different materials, or a stacked 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 stacked in sequence from the emission layer EML without limitation. The thickness of the electron transport region ETR may be, for example, about 100 Å. to about

[0175] The electron transport region ETR may be formed using various methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, and a laser induced thermal imaging (LITI) method.

[0176] In the case where the electron transport region ETR includes the electron transport layer ETL, the electron transport region ETR may include an anthracene derivative. However, embodiments of the inventive concept are not limited thereto. For example, the electron transport region ETR may include tris(8-hydroxyquinoline)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 (Bp hen), 3-(4-biphenyl)-4-phenyl-5-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-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinoline-10-hydroxy)beryllium (Bebq 2 ), 9,10-di(naphthalene-2-yl)anthracene (ADN) or a mixture thereof. The thickness of the electron transport layer ETL may be about to about For example, about to about If the thickness of the electron transport layer ETL satisfies the above range, satisfactory electron transport performance may be obtained without significantly increasing driving voltage.

[0177] When the electron transport region ETR includes an electron injection layer EIL, the electron transport region ETR may use LiF, 8-hydroxyquinoline lithium (LiQ), Li 2 O, BaO, NaCl, CsF, lanthanide metals such as Yb, or metal halides such as RbCl and RbI. However, the embodiments of the inventive concept are not limited thereto. The electron injection layer EIL may also be formed using a mixed material of an electron transport material and an insulating organic metal salt. The organic metal salt may be a material having an energy band gap of about 4 eV or greater. Specifically, the organic metal salt may include, for example, a metal acetate, a metal benzoate, a metal acetoacetate, a metal acetylacetonate, or a metal stearate. The thickness of the electron injection layer EIL may be about 1000 Å. to about For example, about to about In the case where the thickness of the electron injection layer EIL satisfies the above range, satisfactory electron injection performance can be obtained without significantly increasing the driving voltage.

[0178] As described above, the electron transport region ETR may include a hole blocking layer HBL. The hole blocking layer HBL 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), without limitation.

[0179] The second electrode EL2 is disposed on the electron transport region ETR. The second electrode EL2 may be a common electrode or a cathode. The second electrode EL2 may be a transmissive electrode, a transflective electrode or a reflective electrode. When the second electrode EL2 is a transmissive electrode, the second electrode EL2 may be formed using a transparent metal oxide such as ITO, IZO, ZnO, ITZO, or the like.

[0180] In the case where the second electrode EL2 is a transflective 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, a composite 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 transflective layer formed using the above materials and a transparent conductive layer formed using ITO, IZO, ZnO, ITZO, etc.

[0181] Even though not shown, the second electrode EL2 may be connected to the auxiliary electrode. In the case where the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0182] Even though not shown in the drawings, the organic electroluminescent device 10 according to the embodiment of the inventive concept may also include a capping layer (not shown) disposed on the second electrode EL2. The capping layer (not shown) may include, for example, α-NPD, NPB, TPD, m-MTDATA, Alq 3 , CuPc, N4,N4,N4',N4'-tetrakis(biphenyl-4-yl)biphenyl-4,4'-diamine (TPD15), 4,4',4"-tris(carbazol-9-yl)-triphenylamine (TCTA), etc.

[0183] The organic electroluminescent device 10 of the embodiment according to the inventive concept may include the above-mentioned polycyclic compound of the embodiment in at least one of the organic layers disposed between the first electrode EL1 and the second electrode EL2, thereby obtaining enhanced emission efficiency. Specifically, the organic electroluminescent device 10 of the embodiment according to the inventive concept may include the above-mentioned polycyclic compound of the embodiment in the emission layer EML, thereby obtaining low driving voltage and high emission efficiency performance. In addition, the organic electroluminescent device 10 of the embodiment according to the inventive concept may include the above-mentioned polycyclic compound of the embodiment in the emission layer EML, so that the emission layer EML can emit thermally activated delayed fluorescence, thereby obtaining high emission efficiency performance.

[0184] The above-mentioned polycyclic compound including a plurality of electron donors and an electron acceptor connected to the electron donor of the embodiment includes both electron donors and electron acceptors in the molecule, thereby contributing to electron transfer in the molecule. Therefore, the polycyclic compound of the embodiment can be used in the organic layer of the organic electroluminescent device 10 of the embodiment, thereby improving the emission efficiency of the device. In addition, the polycyclic compound of the embodiment includes at least one electron donor including a borane triene core and an electron acceptor including a cyano group, a triazine group or a heteroaryl group with O or S for forming a ring, thereby forming a dipole moment between the electron donor and the electron acceptor in the molecule. Therefore, the polycyclic compound of the embodiment has an increased dipole moment in the molecule, thereby enhancing the emission efficiency when used in the emission layer EML of the organic electroluminescent device 10.

[0185] In addition, the polycyclic compound of the embodiment may emit thermally activated delayed fluorescence, thereby enhancing the emission efficiency of the organic electroluminescent device 10 .

[0186] Hereinafter, the polycyclic compound of the embodiment and the organic electroluminescent device 10 of the embodiment according to the inventive concept will be explained in more detail with reference to specific examples and comparative examples. The following examples are shown only to help understand the inventive concept, and the scope of the inventive concept is not limited thereto.

[0187] [Example]

[0188] 1. Synthesis of polycyclic compounds

[0189] First, the synthesis of the polycyclic compound according to the embodiment of the inventive concept will be explained in more detail with reference to the exemplary synthesis methods of Compound 1, Compound 4, Compound 7, Compound 13, and Compound 18. The following synthesis method is an exemplary embodiment, however, the synthesis method of the polycyclic compound according to the embodiment of the inventive concept is not limited thereto.

[0190] (1) Synthesis of Compound 1

[0191] [Reaction Scheme 1]

[0192]

[0193] <Synthesis of Intermediate A>

[0194] 1,2-Diiodobenzene (1 eq) and (2-bromophenyl)boronic acid (2.1 eq) were dissolved in toluene (500 mL). Pd(PPh 3 ) 4 (0.02 eq) was added thereto. In addition, toluene (400 mL) and 2M K 2 CO 3 (70mL) of saturated solution, and the mixture was stirred under reflux for about 5 hours. After the reaction was completed, the reactant was extracted with dichloromethane (MC) (400mL) and washed with distilled water (150mL), and then the solvent was removed. The solid thus obtained was purified by column chromatography to obtain intermediate A (yield 65.7%). Intermediate A was identified by the molecular weight measured by a mass spectrometer. (C 18 H 12 Br 2 HRMS [M]+: calculated: 388, found: 387)

[0195] <Synthesis of Intermediate B>

[0196] Intermediate A (1 eq) was dissolved in hexane (500 mL). After the reaction vessel was cooled to about 0°C, dimethyl borochloridate (2.2 eq) was slowly added dropwise thereto, and the mixture was stirred for about 5 hours. After the reaction was completed, the reactant was extracted with MC (200 mL) and washed with distilled water (150 mL), and then the solvent was removed. The solid thus obtained was recrystallized with MeOH and ether to obtain intermediate B (yield 55.8%). Intermediate B was identified by the molecular weight measured by a mass spectrometer. (C 18 H12 HRMS [M]+ of BCl: calculated: 275, found: 274)

[0197] <Synthesis of Compound 1>

[0198] [Reaction Scheme 2]

[0199]

[0200] (9,9-Dimethyl-10,10-dioxo-9H-thioxanthen-2,7-diyl)diboronic acid (1 eq) and intermediate B (2.2 eq) were dissolved in toluene (500 mL). Pd(PPh 3 ) 4 (0.02eq) and 2M K 2 CO 3 A saturated solution of (70 mL) was added thereto, and the mixture was stirred under reflux for about 4 hours. After the reaction was completed, the reactant was extracted with MC (400 mL) and washed with distilled water (200 mL), and then the solvent was removed. The solid thus obtained was purified by column chromatography to obtain compound 1 (yield 77.5%). Compound 1 was identified by the molecular weight measured by a mass spectrometer. (C 51 H 36 B 2 O 2 HRMS [M]+ of S: calculated: 734, found: 733)

[0201] (2) Synthesis of Compound 4

[0202] For example, Compound 4 (a polycyclic compound according to an embodiment of the inventive concept) may be synthesized as shown in the following Reaction Scheme 3.

[0203] [Reaction Scheme 3]

[0204]

[0205] (4,6-Dicyano-1,3-phenylene)diboronic acid (1 eq) and intermediate B (2.2 eq) were dissolved in toluene (500 mL). Pd(PPh 3 ) 4 (0.02eq) and 2M K 2 CO 3 A saturated solution of (70 mL) was added thereto, and the mixture was stirred under reflux for about 4 hours. After the reaction was completed, the reactant was extracted with MC (400 mL) and washed with distilled water (200 mL), and then the solvent was removed. The solid thus obtained was purified by column chromatography to obtain compound 4 (yield 66.2%). Compound 4 was identified by the molecular weight measured by a mass spectrometer. (C44 H 26 B 2 N 2 HRMS [M]+: calculated: 604, found: 603)

[0206] (3) Synthesis of Compound 7

[0207] [Reaction Scheme 4]

[0208]

[0209] <Synthesis of Intermediate C>

[0210] (9,9-Dimethyl-10,10-dioxo-9H-thioxanthen-2,7-diyl)diboronic acid (1 eq) and intermediate B (1 eq) were dissolved in toluene (500 mL). Pd(PPh 3 ) 4 (0.02eq) and 2M K 2 CO 3 A saturated solution of (70 mL) was added thereto, and the mixture was stirred under reflux for about 4 hours. After the reaction was completed, the reactant was extracted with MC (400 mL) and washed with distilled water (200 mL), and then the solvent was removed. The solid thus obtained was purified by column chromatography to obtain intermediate C (yield 69.4%). Intermediate C was identified by the molecular weight measured by a mass spectrometer. (C 33 H 26 B 2 O 4 HRMS [M]+ of S: calculated: 540, found: 539)

[0211] <Synthesis of Compound 7>

[0212] Intermediate C (1 eq) and carbazole (1.2 eq) were dissolved in toluene (500 mL). Pd(PPh 3 ) 4 (0.02eq) and 2MK 2 CO 3 The saturated solution of (70mL) was added thereto, and the mixture was stirred under reflux for about 4 hours. After the reaction was completed, the reactant was extracted with MC (400mL) and washed with distilled water (200mL), and then the solvent was removed. The solid thus obtained was purified by column chromatography to obtain compound 7 (yield 82.4%). Compound 7 was identified by the molecular weight measured by a mass spectrometer. (C 45 H 32 BNO 2 HRMS [M]+ of S: calculated: 661, found: 660)

[0213] (4) Synthesis of Compound 13

[0214] [Reaction Scheme 5]

[0215]

[0216] <Synthesis of Intermediate D>

[0217] Intermediate D was synthesized (yield 68%) by performing the same synthesis method as that of Intermediate A except that (2-bromo-3-methylphenyl)boronic acid was used instead of (2-bromophenyl)boronic acid in Reaction Scheme 1. Intermediate D was identified by the molecular weight measured by a mass spectrometer. (C 20 H 16 Br 2 HRMS [M]+: calculated: 416, found: 415)

[0218] <Synthesis of Intermediate E>

[0219] Intermediate E was synthesized by the same synthesis method as that of Intermediate B except that Intermediate D was used instead of Intermediate A in Reaction Scheme 1 (yield 51.7%). Intermediate E was identified by the molecular weight measured by a mass spectrometer. (C 20 H 16 HRMS [M]+ of BCl: calculated: 302, found: 301)

[0220] <Synthesis of Compound 13>

[0221] [Reaction Scheme 6]

[0222]

[0223] Compound 13 (yield 82.7%) was synthesized by the same synthesis method as that of compound 1, except that intermediate E (1.2 eq) was used instead of intermediate B (2.2 eq) in reaction scheme 2. Compound 13 was identified by the molecular weight measured by a mass spectrometer. (C 55 H 44 B 2 O 2 HRMS [M]+ of S: calculated: 790, found: 789)

[0224] (5) Synthesis of Compound 18

[0225] [Reaction Scheme 7]

[0226]

[0227] Intermediate B (1 eq) and (3,5-bis(9H-carbazol-9-yl)-2,4,6-tricyanophenyl)boronic acid (1.2 eq) were dissolved in toluene (500 mL). Pd(PPh 3 ) 4 (0.02eq) and 2M K 2 CO 3 The saturated solution of (70mL) was added thereto, and the mixture was stirred under reflux for about 4 hours. After the reaction was completed, the reactant was extracted with MC (400mL) and washed with distilled water (200mL), and then the solvent was removed. The solid thus obtained was purified by column chromatography to obtain compound 18 (yield 77.9%). Compound 18 was identified by the molecular weight measured by a mass spectrometer. (C 51 H 28 BN 5 HRMS [M]+: calculated: 721, found: 720)

[0228] 2. Evaluation of the energy levels of compounds

[0229] Table 1 shows the HOMO level, LUMO level, lowest singlet excitation energy level (S1 level) and lowest triplet excitation energy level (T1 level) of Example Compound 1, Example Compound 4, Example Compound 7, Example Compound 13 and Example Compound 18, and ΔE ST value.

[0230] The energy level values ​​in Table 1 were calculated by an ab initio molecular orbital method (specifically, by using B3LYP / 6-31G(d) of Gaussian09 (Gaussian, Inc.)). ΔE ST The difference between the lowest singlet excitation energy level (S1 level) and the lowest triplet excitation energy level (T1 level) is shown.

[0231] [Table 1]

[0232]

[0233] Example compound 1, example compound 4, example compound 7, example compound 13, and example compound 18 have a ΔE of about 0.25 eV or less. ST Therefore, it is considered that Example Compound 1, Example Compound 4, Example Compound 7, Example Compound 13, and Example Compound 18 can be used as a dopant material for thermally activated delayed fluorescence. Comparative Compound C1 also has a low ΔE ST value, and appears to be used as a dopant material for thermally activated delayed fluorescence.

[0234] 3. Fabrication and evaluation of organic electroluminescent devices including polycyclic compounds

[0235] (Manufacturing of organic electroluminescent devices)

[0236] The organic electroluminescent device including the polycyclic compound of the embodiment was manufactured by the following method: The organic electroluminescent devices of Examples 1 to 5 were manufactured by using Compound 1, Compound 4, Compound 7, Compound 13 and Compound 18 as dopant materials in the emission layer.

[0237] The organic electroluminescent device of Comparative Example 1 was manufactured by using the following BH1 as a host material and BD1 as a dopant material.

[0238]

[0239] The organic electroluminescent device of Comparative Example 2 was manufactured by using mCBP as in the example as a host material and Comparative Compound C1 as a dopant material.

[0240] Table 2 shows the compounds used in Examples 1 to 5 and Comparative Compound C1.

[0241] [Table 2]

[0242]

[0243] On a glass substrate, there will be approximately The first electrode was patterned with ITO of a thickness of about 1000 nm to form the first electrode, which was washed with isopropyl alcohol and ultrapure water and cleaned with ultrasonic waves, exposed to UV for about 30 minutes, and treated with ozone. Then, NPB was deposited to about 1000 nm. to form a hole injection layer, and deposit mCP to about to form a hole transport layer.

[0244] On the hole transport layer, mCBP and the polycyclic compound of the embodiment or the comparative compound C1 were co-deposited at a ratio of 85:15 to form a That is, in Examples 1 to 5, each of Compound 1, Compound 4, Compound 7, Compound 13, and Compound 18 mixed with mCBP was deposited to form an emission layer. In Comparative Example 1, BH1 and BD1 were mixed and deposited to form an emission layer, and in Comparative Example 2, Comparative Compound C1 mixed with mCBP was deposited to form an emission layer.

[0245] On the emission layer, an electron transport layer is formed using the ETL1 material to about The second electrode is formed of aluminum (Al) to a thickness of about Thickness.

[0246] Materials used for fabrication of organic electroluminescent devices of Examples and Comparative Examples are shown below.

[0247]

[0248] (Performance evaluation of organic electroluminescent devices)

[0249] In Table 3, the evaluation results of the organic electroluminescent devices of Examples 1 to 5 and Comparative Examples 1 and 2 are shown. Table 3 shows the driving voltage, emission efficiency and external quantum efficiency (EQE) of the organic electroluminescent devices manufactured in the Examples and Comparative Examples. In the performance evaluation results of Table 3, the emission efficiency is 10 mA / cm 2 The current efficiency value at the current density.

[0250] [Table 3]

[0251]

[0252]

[0253] Referring to the results in Table 3, it can be found that the organic electroluminescent device using the polycyclic compound according to the embodiment of the inventive concept as an example of the material for the emission layer has a low driving voltage, a high emission efficiency and a high external quantum efficiency when compared with the driving voltage, the emission efficiency and the external quantum efficiency of the comparative example.

[0254] Specifically, when compared with the emission efficiency of Comparative Example 1 including BD1 (a typical dopant material for fluorescence) in the emission layer, the organic electroluminescent devices of Examples 1 to 5 exhibited enhanced emission efficiency. Therefore, it can be found that the polycyclic compounds used in the examples emit thermally activated delayed fluorescence.

[0255] In addition, the organic electroluminescent device of Comparative Example 2 uses the same host material as that in Examples 1 to 5 and Comparative Compound C1 as a dopant. However, compared with the polycyclic compounds used in the examples, Comparative Compound C1 does not include an electron acceptor, so when compared with the driving voltage, emission efficiency, and external quantum efficiency of Comparative Example 2, the organic electroluminescent devices of Examples 1 to 5 appear to exhibit low driving voltage, high emission efficiency, and high external quantum efficiency. That is, when compared with the emission efficiency of Comparative Example 1, the organic electroluminescent device of Comparative Example 2 using Comparative Compound C1 exhibits high emission efficiency, and Comparative Compound C1 has a low ΔE similar to the example compounds. STHowever, the comparative compound C1 has a structure different from that of the example compound, so when compared with the driving voltage, emission efficiency and external quantum efficiency of the example, the organic electroluminescent device of the comparative example 2 seems to exhibit high driving voltage, low emission efficiency and low external quantum efficiency.

[0256] That is, the polycyclic compound according to the embodiment of the inventive concept used in the examples can emit delayed fluorescence, thereby obtaining high device efficiency, compared with the dopant compounds used in Comparative Examples 1 and 2, and the polycyclic compound includes both an electron donor and an electron acceptor in one compound unit. In addition, when compared with the comparative examples, the polycyclic compound used in the examples can obtain enhanced device efficiency with a low driving voltage.

[0257] Organic electroluminescent devices according to embodiments of the inventive concept may achieve improved device performance of low driving voltage and high efficiency.

[0258] The polycyclic compound according to an embodiment of the inventive concept may be included in an emission layer of an organic electroluminescent device, thereby contributing to high efficiency of the device.

[0259] Although exemplary embodiments of the present invention have been described, it is 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 present invention as claimed.

[0260] Thus, the scope of the inventive concepts is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

Claims

1. A polycyclic compound, the polycyclic compound being represented by the following formula 1: [Formula 1] In formula 1, DU1 and DU2 are represented by the following Formula 2-1 or Formula 2-2A, and at least one of DU1 and DU2 is represented by the following Formula 2-1, AU is represented by the following formula 3-1 or formula 3-2, and m is 1 or 2: In formula 2-2A, X2 is a direct key, and n is 1, In Formula 2-1 and Formula 2-2A, Ar1 to Ar5 are independently substituted or unsubstituted benzene rings, and a to e are each independently an integer from 0 to 4, In formula 3-1, R w For cyano, p is 2 or 3, and f is an integer from 0 to 2, In formula 3-2, Y1 is O, S or SO2, Y2 is a direct key or CR f R g ,and g and h are each independently an integer from 0 to 3, In Formula 2-1, Formula 2-2A, Formula 3-1 and Formula 3-2, R1 to R8 and R f and R g are independently a hydrogen atom, a deuterium atom, a methyl group, an ethyl group, an n-propyl group or an isopropyl group.

2. The polycyclic compound according to claim 1, wherein Formula 1 is represented by the following formula 1-1: In formula 1-1, AU, DU2 and m are the same as defined in Formula 1, and Ar1 to Ar3, R1 to R3 and a to c are the same as defined in Formula 2-1.

3. The polycyclic compound according to claim 2, wherein DU2 is represented by any one of D1 and D2 below: In D1 and D2, R1 to R3 and a to c are the same as defined in Formula 2-1 and Formula 2-2A.

4. The polycyclic compound according to claim 1, wherein AU is represented by any one of A1, A2, A5, A6, and A7 below: In A1 and A2, p is 2 or 3.

5. The polycyclic compound according to claim 1, wherein The polycyclic compound represented by Formula 1 is any one selected from the group consisting of compounds represented by the following Compound Group 1: [Compound Group 1] 6. An organic electroluminescent device, comprising: a first electrode; A second electrode, disposed on the first electrode; as well as A plurality of organic layers are disposed between the first electrode and the second electrode, wherein the first electrode and the second electrode each independently include at least one selected from the following: Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, a compound selected from two or more thereof, a mixture selected from two or more thereof, and a transparent metal oxide, At least one of the plurality of organic layers includes a polycyclic compound, and the polycyclic compound is the polycyclic compound according to any one of claims 1 to 5.

7. The organic electroluminescent device according to claim 6, wherein: The plurality of organic layers include: hole transport region; an emission layer disposed on the hole transport region and including the polycyclic compound; and The electron transport region is arranged on the emission layer.

8. The organic electroluminescent device according to claim 7, wherein: The emission layer emits delayed fluorescence.

9. The organic electroluminescent device according to claim 7, wherein: The emission layer is a delayed fluorescence emission layer including a host and a dopant, and the dopant includes the polycyclic compound.

10. The organic electroluminescent device according to claim 7, wherein: The emission layer emits blue light.

11. The organic electroluminescent device according to claim 6, wherein: The plurality of organic layers are disposed by an inkjet process.

12. The organic electroluminescent device according to claim 6, wherein: The transparent metal oxide includes at least one selected from indium tin oxide, indium zinc oxide, zinc oxide, and indium tin zinc oxide.

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