Organic electroluminescent device and polycyclic compound for organic electroluminescent device

Abstract

Provided are an organic electroluminescent device and a polycyclic compound for use in the organic electroluminescent device. The organic electroluminescent device includes: a first electrode; a hole transport region located on the first electrode; an emissive layer located on the hole transport region; an electron transport region located on the emissive layer; and a second electrode located on the electron transport region, wherein the emissive layer includes a polycyclic compound represented by Formula 1.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0158374, filed on December 10, 2018, which is hereby incorporated by reference herein in its entirety. Technical Field

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

[0003] Organic electroluminescent display devices are being actively developed as image display devices. Unlike liquid crystal display devices, organic electroluminescent display devices are so-called self-luminous display devices, in which holes and electrons injected from the first electrode and the second electrode recombine in the emission layer, and the light-emitting material including an organic compound in the emission layer is configured to emit light to display images.

[0004] When organic electroluminescent devices are applied to display devices, reduced driving voltage and increased emission efficiency and lifetime of the organic electroluminescent devices are beneficial, and development of materials for stably achieving the requirements for organic electroluminescent devices is substantially continuously being conducted.

[0005] For example, recently, in order to provide organic electroluminescent devices with high efficiency, technologies for phosphorescent emission utilizing triplet energy or delayed fluorescence emission utilizing a phenomenon in which singlet excitons are generated by collision of triplet excitons (triplet-triplet annihilation, "TTA") are being developed, and development of materials for thermally activated delayed fluorescence ("TADF") utilizing the delayed fluorescence phenomenon is underway. Summary of the Invention

[0006] Embodiments of the present disclosure provide an organic electroluminescent device having a long lifespan and high efficiency, and a polycyclic compound for use in the organic electroluminescent device.

[0007] Embodiments of the present disclosure also provide an organic electroluminescent device including a material configured to emit thermally activated delayed fluorescence and a polycyclic compound serving as the material configured to emit thermally activated delayed fluorescence.

[0008] An embodiment of the present disclosure provides an organic electroluminescent device, comprising: a first electrode; a hole transport region located on the first electrode; an emission layer located on the hole transport region; an electron transport region located on the emission layer; and a second electrode located on the electron transport region, wherein the emission layer comprises a polycyclic compound represented by the following Formula 1:

[0009] Formula 1

[0010]

[0011] In Formula 1, Ring D to Ring H are each independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, and Y1 and Y2 are each independently O or S.

[0012] In an embodiment, the emission layer may emit delayed fluorescence.

[0013] In an embodiment, the emission layer may be a delayed fluorescent emission layer including a host and a dopant, and the dopant may include a polycyclic compound.

[0014] In an embodiment, the emitting layer may be a thermally activated delayed fluorescent emitting layer configured to emit blue light.

[0015] In Formula 1, rings D to F may each independently be a substituted or unsubstituted aryl group having 6 to 30 ring-constituting carbon atoms.

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

[0017] Formula 2

[0018]

[0019] In Formula 2, X1 to X8 are independently N or CR A , R1 to R3 and R A are independently a hydrogen atom, a deuterium atom, a halogen atom, a nitrile group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, or are combined with adjacent groups to form a ring, "a" and "b" are independently an integer from 0 to 4, and Y1 and Y2 are the same as defined in Formula 1.

[0020] In an embodiment, Formula 2 may be represented by the following Formula 3:

[0021] Formula 3

[0022]

[0023] In Formula 3, R4 to R 19 are independently a hydrogen atom, a deuterium atom, a halogen atom, a nitrile group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, or are combined with adjacent groups to form a ring, and Y1, Y2 and R3 are the same as defined in Formula 2.

[0024] In the embodiment, R4 and R5, R5 and R6, R6 and R7, R8 and R9, R9 and R 10 、R 10 and R 11 、R 12 and R 13 、R 13 and R 14 、R 14 and R 15 、R 16 and R 17 、R 17 and R 18 and R 18 and R 19 The groups in at least one pair thereof may be bonded to each other to form a ring represented by any one of the following Formulae 4-1 to 4-4:

[0025]

[0026]

[0027] In formulas 4-1 to 4-4, R 20 to R 26 "k" to "n" are each independently a hydrogen atom, a deuterium atom, a halogen atom, a nitrile group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, and "k" to "n" are each independently an integer from 0 to 4.

[0028] In the embodiment, R4 and R8, R7 and R 12 and R 11 and R 16 At least one pair thereof may be combined with -O- or -S- to form a ring.

[0029] In an embodiment, Formula 3 may be expressed by any one of the following Formulas 5-1 to 5-3:

[0030] Formula 5-1

[0031]

[0032] Formula 5-2

[0033]

[0034] Formula 5-3

[0035]

[0036] In Formula 5-1 to Formula 5-3, Z1 to Z3 are independently O or S, R3 to R 19 , Y1 and Y2 are the same as defined in Formula 3.

[0037] In Formula 1, Y1 and Y2 may be the same, for example, Y1 and Y2 may both independently be oxygen.

[0038] In an embodiment, the compound represented by Formula 1 may be any one of the compounds represented in Compound Group 1.

[0039] In an embodiment of the present disclosure, a polycyclic compound represented by Formula 1 is provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are included to provide a further understanding of the subject matter of the present disclosure and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. In the drawings:

[0041] Figure 1 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure;

[0042] Figure 2 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure; and

[0043] Figure 3 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0044] The subject matter of the present disclosure may have various modifications and may be implemented in different forms, and example embodiments will be explained in more detail with reference to the accompanying drawings. However, the subject matter of the present disclosure may be implemented in different forms and should not be interpreted as being limited to the embodiments set forth herein. On the contrary, all modifications, equivalents, and substitutes included in the spirit and technical scope of the present disclosure should be included in the present disclosure.

[0045] The same reference numerals always represent the same elements. In the accompanying drawings, the size of the structure may be exaggerated for clarity of illustration. 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. Therefore, without departing from the spirit and scope of the present disclosure, the first element may be named as the second element. Similarly, the second element may be named as the first element. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form.

[0046] It will also be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of the stated features, quantities, actions, operations, elements, parts, or combinations thereof, but does not preclude the presence or addition of one or more other features, quantities, actions, operations, elements, parts, or combinations thereof. It will also be understood that when a layer, film, region, plate, etc. is referred to as being "on" another layer, film, region, plate, etc., the layer, film, region, plate, etc. may be "directly on" the other layer, film, region, plate, etc., or intervening layers, films, regions, plates, etc. may also be present.

[0047] In the following, reference will be made to Figures 1 to 3 An organic electroluminescent device according to an embodiment of the present disclosure is explained.

[0048] Reference 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 stacked in the stated order (eg, layered one after another).

[0049] The first electrode EL1 and the second electrode EL2 are positioned opposite each other, and a plurality of organic layers may be located 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.

[0050] On the other hand, when Figure 1 In comparison, Figure 2 The cross-sectional view of the organic electroluminescent device 10 of the 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 In comparison, 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.

[0051] In the organic electroluminescent device 10 of the disclosed embodiment, the first electrode EL1 has conductivity (eg, is electrically conductive). The first electrode EL1 may be formed using a metal alloy or a conductive compound. The first electrode EL1 may be, for example, an anode.

[0052] The first electrode EL1 may be a transmissive electrode, a transflective electrode, or a reflective electrode. If the first electrode EL1 is a transmissive electrode, the first electrode EL1 may be formed using a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO). If 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). Furthermore, the first electrode EL1 may have a structure including multiple layers, including a reflective layer and / or a transflective layer formed using the above materials and a transmissive conductive layer formed using ITO, IZO, ZnO, and / or ITZO. For example, the first electrode EL1 may include multiple layers including ITO / Ag / ITO.

[0053] The hole transport region HTR is disposed on the first electrode EL1. The hole transport region HTR may include at least one selected from a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer, and an electron blocking layer EBL.

[0054] 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-layered structure including a plurality of layers formed using the same or a plurality of different materials.

[0055] For example, the hole transport region HTR may have a structure of a single layer of the hole injection layer HIL or the hole transport layer HTL, and may have a structure of a single layer formed using a hole injection material and a hole transport material. In some embodiments, the hole transport region HTR may have a structure of a single layer formed using a plurality of different materials, or may have 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 stacked from the first electrode EL1, without limitation.

[0056] The hole transport region HTR may be formed using various suitable methods such as, for example, 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 / or a laser induced thermal imaging (LITI) method.

[0057] The hole injection layer HIL of the organic electroluminescent device 10 of the embodiment may include any suitable hole injection material available in the art. 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-(di-m-tolyl-amino)-phenyl]-biphenyl-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-2,2'-dimethyl-biphenyl-4,4'-diamine (α-NPD ), 4,4',4"-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tris(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) and / or dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), etc. However, the embodiments of the present disclosure are not limited thereto.

[0058] The hole transport layer HTL of the organic electroluminescent device 10 of the embodiment may include any suitable hole transport material available in the art. For example, the hole transport layer HTL may include 1,1-bis[(di-4-methylphenylamino)phenyl]cyclohexane (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"-tris(N-carbazolyl)triphenylamine (TCTA), N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB) and / or N,N'-bis(1-naphthyl)-N,N'-diphenyl-2,2'-dimethyl-biphenyl-4,4'-diamine (α-NPD), etc. However, the embodiments of the present disclosure are not limited thereto.

[0059] On the other hand, the hole transport region HTR may further include an electron blocking layer EBL, which may be located between the hole transport layer HTL and the emission layer EML. The electron blocking layer EBL may prevent or reduce electron injection from the electron transport region ETR into the hole transport region HTR.

[0060] The electron blocking layer EBL may include any suitable electron blocking material available in the art. The electron blocking layer EBL may include, for example, carbazole derivatives (such as N-phenylcarbazole and / or 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″-tris(N-carbazolyl)triphenylamine (TCTA)), N,N′-di(naphth-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) and / or 1,3-di(carbazol-9-yl)benzene (mCP), etc. In addition, as described above, the electron blocking layer EBL may include a polycyclic compound according to an embodiment of the present disclosure.

[0061] The thickness of the hole transport region HTR may be approximately to approximately For example, for approximately to approximately The thickness of the hole injection layer HIL may be, for example, approximately to approximately The thickness of the hole transport layer HTL may be approximately to approximately For example, the thickness of the electron blocking layer EBL may be about to approximately 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, appropriate or satisfactory hole transport properties may be achieved without significantly increasing driving voltage.

[0062] 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 include, for example, a p-dopant. The p-dopant may be selected from quinone derivatives, metal oxides, and cyano-containing compounds 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)) or metal oxides (such as tungsten oxide and molybdenum oxide), without limitation.

[0063] 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 selected from a hole buffer layer and an electron blocking layer EBL. The hole buffer layer may compensate for the optical resonance distance according to the wavelength of light emitted from the emission layer EML and improve luminous efficiency. The material included in the hole transport region HTR may be used as the material included in the hole buffer layer.

[0064] The emission layer EML is provided on the hole transport region HTR. The emission layer EML may have, for example, an approximately to approximately 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 the same or a plurality of different materials.

[0065] The emission layer EML may emit one selected from 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.

[0066] 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 some embodiments, the emission layer EML may include a light-emitting component configured to emit thermally activated delayed fluorescence. In an embodiment, the emission layer EML may be an emission layer configured to emit blue light by thermally activated delayed fluorescence.

[0067] In the specification, -----* indicates a linking site (eg, a position of a chemical bond).

[0068] In this specification, the term "substituted or unsubstituted" means unsubstituted or substituted with at least one substituent selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, a hydroxyl group, an amino group, a silyl group, a boron group, a phosphine oxide group, a phosphine sulfide group, an alkyl group, an alkenyl group, an alkoxy group, an aryl group, an aryloxy group, and a heteroaryl group. Furthermore, each of the aforementioned substituents may be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group or a phenyl group substituted with a phenyl group.

[0069] In this specification, the term "forming a ring by combining with an adjacent group" may mean forming a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle by combining with an adjacent group. As used herein, the term "hydrocarbon ring" includes aliphatic hydrocarbon rings and aromatic hydrocarbon rings. As used herein, the term "heterocycle" includes aliphatic heterocycles and aromatic heterocycles. The ring formed by combining with an adjacent group may be a monocyclic ring or a polycyclic ring. In addition, the ring formed by combining with an adjacent group may combine with another ring to form a spirocyclic structure.

[0070] In this specification, the term "adjacent group" may refer to a substituent substituted on an atom directly bonded to the atom substituted with the corresponding substituent, another substituent substituted on the atom substituted with the corresponding substituent, or a substituent located at the closest position to the corresponding substituent. For example, in 1,2-dimethylbenzene, two methyl groups can be interpreted as "adjacent groups" to each other, and in 1,1-diethylcyclopentane, two ethyl groups can be interpreted as "adjacent groups" to each other.

[0071] In the present specification, the term "halogen atom" may mean a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

[0072] In this specification, the term "alkyl" may refer to an alkyl group in a linear, branched or cyclic form (or 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-heneicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, n-triacontyl and the like, without limitation.

[0073] In this specification, the term "aryl" refers to an optional 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 ring carbon atoms in the aryl group 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, pentyl, hexaphenyl, benzo[9,10]phenanthrenyl, pyrenyl, benzofluoranthenyl, Base, etc., without restriction.

[0074] In the present specification, the fluorenyl group may be substituted, and two substituents of the fluorenyl group may be combined with each other to form a spirocyclic structure. Examples of substituted fluorenyl groups are as follows. However, the embodiments of the present disclosure are not limited thereto.

[0075]

[0076] In the present specification, the heteroaryl group may be a heteroaryl group including at least one heteroatom selected from O, N, P, Si, and S as a ring-forming heteroatom. The number of ring carbon atoms in the heteroaryl group may be 2 to 30 or 2 to 20. The heteroaryl group may be a monocyclic heteroaryl group or a polycyclic heteroaryl group. Examples of heteroaryl groups (e.g., polycyclic heteroaryl groups) may have a two-ring or three-ring structure. Examples of heteroaryl groups may include, without limitation, 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, dibenzothiazinyl, dibenzothiorol, dibenzofuranyl, and the like.

[0077] In this specification, a silyl group includes an alkylsilyl group and / or an arylsilyl group. Examples of silyl groups may include trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, etc. However, embodiments of the present disclosure are not limited thereto.

[0078] In this specification, the number of carbon atoms in the amino group is not particularly limited, but may be 1 to 30. The amino group may include an alkylamino group and / or an arylamino group. Examples of the amino group include methylamino, dimethylamino, phenylamino, naphthylamino, 9-methyl-anthrylamino, triphenylamino, and the like, without limitation.

[0079] In an embodiment, the emission layer EML includes a polycyclic compound represented by Formula 1.

[0080] Formula 1

[0081]

[0082] In Formula 1, Ring D to Ring H are each independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0083] In Formula 1, Y1 and Y2 are each independently O or S.

[0084] According to an embodiment of the present disclosure, a polycyclic compound includes a ring containing nitrogen and boron as shown in Formula 1. The polycyclic compound may include two rings each containing boron and a chalcogen element (such as oxygen or sulfur). For example, in an embodiment of the polycyclic compound, a carbon atom adjacent to any boron atom is directly or indirectly cross-linked with a chalcogen element (such as oxygen and / or sulfur) to form a condensed polycyclic compound.

[0085] In an embodiment, Ring D to Ring F of Formula 1 may each independently be a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms.

[0086] In an embodiment, Y1 and Y2 of Formula 1 may be the same. For example, Y1 and Y2 may each independently be oxygen.

[0087] In an embodiment, Formula 1 may be represented by the following Formula 2:

[0088] Formula 2

[0089]

[0090] In Formula 2, X1 to X8 can each independently be N or CR A .

[0091] In Formula 2, R1 to R3 and R A Each may independently be a hydrogen atom, a deuterium atom, a halogen atom, a nitrile group (also referred to as a "cyano group"), a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, or may combine with an adjacent group to form a ring.

[0092] In Formula 2, "a" and "b" may each independently be an integer from 0 to 4. On the other hand, if "a" is 2 or greater, the plurality of R1 groups may be the same or different, and if "b" is 2 or greater, the plurality of R2 groups may be the same or different.

[0093] In Formula 2, Y1 and Y2 are the same as defined in Formula 1.

[0094] In an embodiment, all X1 to X8 in Formula 2 may be CR A In this case, Equation 2 can be expressed as Equation 3 below:

[0095] Formula 3

[0096]

[0097] In Formula 3, R4 to R 19 Each of them may independently be a hydrogen atom, a deuterium atom, a halogen atom, a nitrile group (also referred to as a "cyano group"), a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms, or may combine with adjacent groups to form a ring.

[0098] In Formula 3, Y1, Y2 and R3 are the same as defined in Formula 2.

[0099] In the embodiment, R4 and R5, R5 and R6, R6 and R7, R8 and R9, R9 and R 10 、R 10 and R 11 、R 12 and R 13 、R 13 and R 14 、R 14 and R 15 、R 16 and R 17 、R 17 and R 18 and R 18 and R 19 The groups in at least one pair thereof may be bonded to each other to form a ring represented by any one of the following Formulae 4-1 to 4-4:

[0100]

[0101] In Formula 4-1 to Formula 4-4, R 20 to R 26 Each of them may independently be a hydrogen atom, a deuterium atom, a halogen atom, a nitrile group (also referred to as a "cyano group"), a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0102] In Formula 4-1 to Formula 4-4, "k" to "n" are each independently an integer of 0 to 4. On the other hand, if "k" is 2 or greater, a plurality of R 20 The groups may be the same or different. If "l" is 2 or more, then multiple R 23 The groups may be the same or different. If "m" is 2 or greater, then multiple R 25 The groups may be the same or different. If "n" is 2 or greater, multiple R 26 The groups may be the same or different.

[0103] In the embodiment, R4 and R8, R7 and R 12 and R 11 and R 16 At least one pair thereof may be combined with -O- or -S- to form a ring.

[0104] For example, in the case where R4 and R8 of Formula 3 are combined with -O- or -S- to form a ring, Formula 3 can be represented by Formula 5-1, where R7 and R 12 When combined with -O- or -S- to form a ring, Formula 3 can be represented by Formula 5-2. 11 and R 16 In the case of combining with -O- or -S- to form a ring, Formula 3 can be represented by Formula 5-3. However, the embodiments of the present disclosure are not limited thereto, and R4 and R8, R7 and R 12 and R 11 and R 16 Two or more pairs among them may combine with -O- or -S- to form a ring.

[0105] Formula 5-1

[0106]

[0107] Formula 5-2

[0108]

[0109] Formula 5-3

[0110]

[0111] In Formulae 5-1 to 5-3, Z1 to Z3 may each independently be O or S.

[0112] In Formula 5-1 to Formula 5-3, R3 to R 19 , Y1 and Y2 are the same as defined in Formula 3.

[0113] The polycyclic compound of the embodiment represented by Formula 1 may be a material configured to emit delayed fluorescence. The polycyclic compound of the embodiment may be a material configured to provide thermally activated delayed fluorescence. For example, the polycyclic compound represented by Formula 1 may be used as a blue emitting material configured to emit thermally activated delayed fluorescence. However, the embodiments of the present disclosure are not limited thereto. The polycyclic compound of the embodiment may be used as a material configured to emit thermally activated delayed fluorescence of green or red light.

[0114] The polycyclic compound of the embodiment represented by Formula 1 may be any one of the compounds represented in the following Compound Group 1:

[0115] Compound Group 1

[0116]

[0117]

[0118]

[0119]

[0120] The polycyclic compound represented by Formula 1 is used in the organic electroluminescent device 10 of the embodiment and can improve the efficiency and lifespan of the organic electroluminescent device 10. In some embodiments, 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 lifespan of the organic electroluminescent device 10.

[0121] In an embodiment, the emission layer EML includes a host and a dopant, the host may be a host configured to emit delayed fluorescence, and the dopant may be a dopant configured to emit delayed fluorescence. On the other hand, the polycyclic compound of the embodiment represented by Formula 1 may be included as a dopant material of the emission layer EML. For example, the polycyclic compound of the embodiment represented by Formula 1 may be used as a TADF dopant.

[0122] On the other hand, in an embodiment, the emission layer EML may include any suitable host material available in the art. For example, in an embodiment, the emission layer EML may include tris(8-hydroxyquinoline)aluminum (Alq3), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (mCBP), 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), 2-tert-butyl-9,10-di(naphthalene-2-yl)anthracene (TBADN), distyryl arylide (DSA), 4,4'-bis(9-carbazolyl)-2,2'-diphenylamine (D ... Methyl-biphenyl (CDBP), 2-methyl-9,10-bis(naphthalene-2-yl)anthracene (MADN), bis[2-(diphenylphosphino)phenyl]ether oxide (bis[2-((oxy)diphenylphosphino)phenyl]ether) (DPEPO), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetrasiloxane (DPSiO4), 2,8-bis(diphenylphosphoryl)dibenzofuran (PPF), etc. are used as host materials. However, the embodiments of the present disclosure are not limited thereto. In addition to the host materials disclosed herein, any suitable host material available in the art that is configured to emit delayed fluorescence may be included.

[0123] On the other hand, in the organic electroluminescent device 10 of the embodiment, the emission layer EML may further include any suitable dopant material available in the art. In the embodiment, the emission layer EML may include styryl derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]stilbene (DPAVB), and N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-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, and 1,4-bis(N,N-diphenylamino)pyrene), etc. as dopants.

[0124] Refer again Figures 1 to 3In the organic electroluminescent device 10 of the embodiment, the electron transport region ETR is provided on the emission layer EML. The electron transport region ETR may include at least one selected from the hole blocking layer HBL, the electron transport layer ETL, and the electron injection layer EIL. However, the embodiments of the present disclosure are not limited thereto.

[0125] 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 the same or a plurality of different materials.

[0126] 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 having a plurality of different materials, or may have 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 stacked from the first electrode EL1, without limitation. The thickness of the electron transport region ETR may be, for example, approximately to approximately

[0127] The electron transport region ETR may be formed using various suitable methods such as, for example, 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 / or a laser induced thermal imaging (LITI) method.

[0128] If the electron transport region ETR includes an electron transport layer ETL, the electron transport region ETR may include, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 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-1,1 0-phenanthroline (Bphen), 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-hydroxyquinolinolato-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinolinolato-10-hydroxy)beryllium (Bebq2), 9,10-di(naphthalene-2-yl)anthracene (ADN), or a mixture thereof, without limitation.

[0129] If the electron transport region ETR includes an electron transport layer ETL, the thickness of the electron transport layer ETL may be approximately to approximately and can be, for example, approximately to approximately If the thickness of the electron transport layer ETL satisfies the above range, appropriate or satisfactory electron transport properties may be obtained without significantly increasing driving voltage.

[0130] If the electron transport region ETR includes an electron injection layer EIL, the electron transport region ETR may include, for example, a metal halide (such as LiF, NaCl, CsF, RbCl, RbI and / or KI), a lanthanide metal (such as Yb), a metal oxide (such as Li2O, BaO) and / or lithium hydroxyquinoline (LiQ). However, the embodiments of the present disclosure 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 (e.g., an organic metal salt). The organic metal salt may be a material having an energy band gap of about 4 eV or greater. In some embodiments, the organic metal salt may include, for example, a metal acetate, a metal benzoate, a metal acetoacetate, a metal acetylacetonate and / or a metal stearate.

[0131] 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 approximately and can be approximately to approximately If the thickness of the electron injection layer EIL satisfies the above range, appropriate or satisfactory electron injection properties may be obtained without causing a significant increase in driving voltage.

[0132] The electron transport region ETR may include the hole blocking layer HBL as described above. The hole blocking layer HBL may include, for example, at least one selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and 4,7-diphenyl-1,10-phenanthroline (Bphen). However, the embodiments of the present disclosure are not limited thereto.

[0133] The second electrode EL2 is disposed on the electron transport region ETR. The second electrode EL2 is conductive (e.g., electrically conductive). 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 transflective electrode, or a reflective electrode. If the second electrode EL2 is a transmissive electrode, the second electrode EL2 may include a transparent metal oxide such as ITO, IZO, ZnO, and / or ITZO.

[0134] If 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, and / or ITZO, etc.

[0135] In some embodiments, the second electrode EL2 may be combined with an auxiliary electrode. If the second electrode EL2 is combined with the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0136] In the organic electroluminescent device 10, when a voltage is applied to each of the first electrode EL1 and the second electrode EL2, holes injected from the first electrode EL1 can move to the emission layer EML via the hole transport region HTR, and electrons injected from the second electrode EL2 can move to the emission layer EML via the electron transport region ETR. The electrons and holes recombine in the emission layer EML to generate excitons, and the excitons can emit light by transitioning from an excited state to a ground state.

[0137] If the organic electroluminescent device 10 is a top emission type (or kind), the first electrode EL1 may be a reflective electrode, and the second electrode EL2 may be a transmissive electrode or a transflective electrode. If the organic electroluminescent device 10 is a bottom emission type (or kind), the first electrode EL1 may be a transmissive electrode or a transflective electrode, and the second electrode EL2 may be a reflective electrode.

[0138] The organic electroluminescent device 10 of the embodiment of the present disclosure uses a polycyclic compound as a material for the emission layer EML and may have improved emission efficiency and lifespan characteristics.

[0139] An embodiment of the present disclosure provides a polycyclic compound represented by the following Formula 1:

[0140] Formula 1

[0141]

[0142] In Formula 1, Ring D to Ring H are each independently a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 30 ring carbon atoms.

[0143] In Formula 1, Y1 and Y2 are each independently O or S.

[0144] The same explanation of the polycyclic compound in the organic electroluminescent device 10 of the embodiment can be applied to the polycyclic compound of the embodiment represented by Formula 1.

[0145] The polycyclic compound according to the embodiment may be any one selected from the compounds represented in the above compound group 1.

[0146] Hereinafter, the subject matter of the present disclosure will be explained with reference to examples and comparative examples.The following embodiments are merely illustrated to help understand the present disclosure, and the scope of the present disclosure is not limited thereto.

[0147] Example

[0148] 1. Synthesis of polycyclic compounds

[0149] First, the synthesis method of the polycyclic compound according to the embodiment of the present disclosure will be explained with reference to the synthesis method of compound 5, compound 10 and compound 15. In addition, the synthesis method of the polycyclic compound explained below is only an example, and the synthesis method of the polycyclic compound according to the embodiment of the present disclosure is not limited thereto.

[0150] (1) Synthesis of compound 5

[0151] Synthesis of compound A-3

[0152]

[0153] Under Ar atmosphere, compound A-1 (2.0 g, 10 mmol), compound A-2 (6.9 g, 11 mmol), Pd (dba) 2 (0.19 g, 0.21 mmol), BF 4 PH (tBu) 3 (0.24 g, 0.81 mmol), NaO tBu (1.2 g, 13 mmol) and 50 mL of toluene were stirred at about 80 ° C for about 4 hours, followed by filtration through a silica gel pad using a toluene solvent. The reaction solution thus obtained was concentrated and subjected to silica gel column chromatography (eluent: hexane and toluene). Then, recrystallization was performed using a mixed solvent of hexane and toluene to obtain 6.1 g of a white solid in a yield of 82%. The molecular weight of the compound thus obtained was measured by fast atom bombardment-mass spectrometry ("FAB-MS") and found to be 736, and the compound was identified as compound A-3.

[0154] Synthesis of compound 5

[0155]

[0156] Under Ar atmosphere, compound A-3 (2.0 g, 2.8 mmol), triphenylborane (1.3 g, 5.4 mmol) and 30 mL of o-dichlorobenzene (" ODCB ") are stirred. Boron triiodide (2.7 g, 6.8 mmol) is added thereto, followed by heating and stirring at approximately 180 ° C for approximately 24 hours. Then, product therefrom is cooled to room temperature, and phosphate buffer is added thereto. Product therefrom is extracted with toluene, dried with MgSO4, and filtered through a silica gel pad using toluene solvent. Then, a mixed solvent of hexane and toluene is used to clean by ultrasonic waves and recrystallize using toluene, obtaining 1.2 g of a yellow solid in a yield of 60%. The molecular weight of the compound thus obtained is measured by FAB-MS, and it is found that the molecular weight is 752, and the compound is identified as compound 5.

[0157] (2) Synthesis of Compound 10

[0158] Synthesis of compound B-2

[0159]

[0160] Except using compound B-1 (4.3g, 11mmol) to replace compound A-2 to perform synthesis, compound B-2 is synthesized by the same steps as those of the synthesis of compound A-3. The reaction solution thus obtained is concentrated, and silica gel column chromatography (eluent: hexane and toluene) is performed. Then, recrystallization is performed using a mixed solvent of hexane and toluene to obtain 4.0g of white solid with a yield of 78%. The molecular weight of the compound thus obtained is measured by FAB-MS, and it is found that the molecular weight is 500, and the compound is determined to be compound B-2.

[0161] Synthesis of compound 10

[0162]

[0163] Except using compound B-2 (2.0g, 4.0mmol) to replace compound A-3 to perform synthesis, compound 10 is synthesized by the step substantially identical with the step of synthesizing compound 5.Then, products therefrom is cooled to room temperature, and phosphate buffer is added thereto.Toluene is used to extract products therefrom, and a mixed solvent of hexane and toluene is used to clean by ultrasonic wave and recrystallize using toluene, and 1.2g of yellow solid is obtained with a yield of 60%. The molecular weight of the compound thus obtained is measured by FAB-MS, and it is found that the molecular weight is 515, and the compound is identified as compound 10.

[0164] (3) Synthesis of Compound 15

[0165] Synthesis of compound C-3

[0166]

[0167] Except using compound C-1 (2.0g, 6.8mmol) and compound C-2 (4.3g, 7.5mmol) to replace compound A-1 and compound A-2 respectively to perform synthesis, compound C-3 is synthesized by the step substantially the same as the step of synthesizing compound A-3. The reaction solution thus obtained is concentrated, and silica gel column chromatography (eluent: hexane and toluene) is performed. Then, recrystallization is performed using a mixed solvent of hexane and toluene, and 4.2g of white solid is obtained with a yield of 79%. The molecular weight of the compound thus obtained is measured by FAB-MS, and it is found that the molecular weight is 777, and the compound is determined to be compound C-3.

[0168] Synthesis of compound 15

[0169]

[0170] Except using compound C-3 (2.0g, 2.6mmol) to replace compound A-3 to perform synthesis, compound 15 is synthesized by the steps substantially the same as those of synthesizing compound 5. Then, the product obtained is cooled to room temperature, and phosphate buffer is added thereto. Toluene is used to extract the product obtained, and a mixed solvent of hexane and toluene is used to clean it by ultrasonic wave. Then, toluene is used to perform recrystallization, and 1.7g of yellow solid is obtained with a yield of 81%. The molecular weight of the compound thus obtained is measured by FAB-MS, and it is found that the molecular weight is 793, and the compound is determined to be compound 15.

[0171] 2. Fabrication and evaluation of organic electroluminescent devices containing polycyclic compounds

[0172] Fabrication of organic electroluminescent devices

[0173] The organic electroluminescent device of the exemplary embodiment including the polycyclic compound of the exemplary embodiment in the emission layer is manufactured by the method described below. The polycyclic compounds of Compound 5, Compound 10 and Compound 15 are used as materials for the emission layer to manufacture the organic electroluminescent devices of Examples 1 to 3, respectively. The compounds used in the emission layer in Examples 1 to 3 and Comparative Examples 1 to 3 (Comparative Compound X-1, Comparative Compound X-2 and Comparative Compound X-3, respectively) are shown below.

[0174] Example compounds

[0175]

[0176] Comparative compounds

[0177]

[0178] The organic electroluminescent devices of Examples and Comparative Examples were manufactured by the method described below.

[0179] On a glass substrate, a layer with a thickness of approximately The ITO was patterned and washed with ultrapure water and subjected to UV ozone treatment for about 10 minutes. Then, HAT-CN was deposited to a thickness of about α-NPD was deposited to a thickness of approximately The mCP was deposited to a thickness of approximately to form a hole transport region.

[0180] Then, each of the polycyclic compounds of the examples and the comparative compounds was co-deposited with mCBP at a ratio of 1:99 to form a film having a thickness of about That is, in order to form the emission layer by co-deposition, in Examples 1 to 3, each of Compound 5, Compound 10, and Compound 15 was mixed with mCBP and deposited, and in Comparative Examples 1 to 3, each of Comparative Compound X-1, Comparative Compound X-2, and Comparative Compound X-3 was mixed with mCBP and deposited.

[0181] On the emission layer, TPBi is formed with a thickness of about layer, and using LiF to form a thickness of approximately Then, aluminum (Al) is used to form a layer with a thickness of about the second electrode.

[0182] In an example, the hole transport region, the emission layer, the electron transport region, and the second electrode are formed by using a vacuum deposition apparatus.

[0183] Evaluation of properties of organic electroluminescent devices

[0184] Evaluation of emission properties

[0185] The properties were evaluated using a JASCO V-670 spectrometer, and the emission spectrum was measured by controlling a 5.0 mM toluene solution at room temperature and at approximately 77 K. The maximum emission wavelength (λ max ) and the half width of the emission spectrum. In addition, the triplet energy level (T1 level) was calculated from the onset value of the emission spectrum at approximately 77 K.

[0186] Table 1

[0187] Compound <![CDATA[λ max (nm)]]> Half width (nm) T1(eV) Example Compound 5 448 24 2.72 Example Compound 10 445 23 2.78 Example Compound 15 451 22 2.69 Comparative compound X-1 486 32 2.53 Comparative compound X-2 475 25 2.57 Comparative Compound X-3 461 40 2.64

[0188] Evaluation of device properties

[0189] In order to evaluate the properties of the organic electroluminescent devices of Examples and Comparative Examples, the maximum emission wavelength (λ max ), the maximum external quantum yield (EQE max ) and at 1000cd / m 2 The external quantum yield (EQE 1000nit ).

[0190] Table 2

[0191] Device Emitting layer dopants <![CDATA[λ max (nm)]]> <![CDATA[EQE max (%)]]> <![CDATA[EQE 1000nit (%)]]> Example 1 Example Compound 5 454 13.7 10.4 Example 2 Example Compound 10 451 13.2 10.1 Example 3 Example Compound 15 462 20.4 13.6 Comparative Example 1 Comparative compound X-1 501 13.6 4.8 Comparative Example 2 Comparative compound X-2 490 12.1 4.5 Comparative Example 3 Comparative Compound X-3 462 16.3 8.6

[0192] With reference to Table 1, it was found that, when compared with the comparative compounds, the polycyclic compounds of the disclosed embodiments had smaller half-widths and higher triplet energy levels. In the polycyclic compounds of the embodiments, the carbon atoms adjacent to the rings comprising B and N were cross-linked with oxygen elements to form condensed polycyclic compounds. Therefore, the core structure of the condensed polycyclic compound can be distorted, the conjugation of the condensed polycyclic compound can be reduced, the wavelength of the light emitted by the condensed polycyclic compound can be reduced, and the triplet energy level of the condensed polycyclic compound can be increased.

[0193] With reference to Table 2, it is found that the organic electroluminescent device using the polycyclic compound of the embodiment as the doping material of the emission layer achieves increased emission efficiency at high brightness and deepens the blue color of the emitted light. The condensed polycyclic compound of the embodiment may have a reduced half-width, an increased triplet energy level, may promote intersystem crossing, may improve the emission efficiency of the device including the condensed polycyclic compound, and may achieve deep blue light emission from the device. In addition, the half-width of the emitted light is not affected by the oxygen group elements, and a narrow emission spectrum of the device may be achieved. Therefore, an organic electroluminescent device with high efficiency may be provided, which is capable of emitting deep blue light with high color purity.

[0194] When compared with the examples, in Comparative Compound X-1, the ring including B and N does not have a cross-linked structure, and the planarity of the core structure of the compound is increased to a very high level. Therefore, due to the increase in the wavelength of the maximum emission wavelength and the decrease in the triplet energy level of Comparative Example 1, deterioration in emission efficiency at high brightness was observed.

[0195] In Comparative Compound X-2, the ring including B and N has a crosslinked structure, but the crosslink is formed only by a single bond, so the core structure of this compound is highly planar. Therefore, it is believed that, as in Comparative Example 1, an increase in the wavelength of the device and degradation of the emission efficiency at high brightness were observed in Comparative Example 2.

[0196] In comparative compound X-3, the ring containing B and N forms a crosslinked structure via the arylamino group. This crosslinked structure distorts the core structure of the compound and reduces the wavelength. However, conjugation with the aryl group of the substituted arylamino group degrades the triplet energy level. Consequently, reduced efficiency at high brightness was observed in Comparative Example 3.

[0197] The organic electroluminescent device according to the embodiment of the present disclosure can achieve high efficiency and long lifespan.

[0198] The polycyclic compound according to an embodiment of the present disclosure may improve the lifespan and efficiency of an organic electroluminescent device.

[0199] For ease of explanation, spatially relative terms such as “under,” “below,” “below,” “under,” “above,” “on,” etc. may be used herein to describe the relationship of one element or feature to another element or feature as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figure is flipped, an element described as “under” or “below” or “under” other elements or features will then be positioned as “above” the other elements or features. Thus, the example terms “under” and “under” can encompass both above and below orientations. The device can be positioned otherwise (e.g., rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein should be interpreted accordingly.

[0200] It will be understood that when an element or layer is referred to as being "on," "connected to," or "bound to" another element or layer, the element or layer can be directly on, directly connected to, or directly bound to the other element or layer, or there can be one or more intermediate elements or layers. In addition, it will be understood that when an element or layer is referred to as being "between" two elements or layers, the element or layer can be the only element or layer between the two elements or layers, or there can be one or more intermediate elements or layers. As used herein, the term "and / or" includes any and all combinations of one or more of the relevant listed items. When a statement such as "at least one of..." follows a list of elements (elements), it is the elements (elements) of the entire list that are modified, rather than the individual elements (elements) in the list.

[0201] As used herein, the terms "substantially," "approximately," and similar terms are used as terms of approximation rather than as terms of degree, and are intended to account for inherent deviations in measurements or calculations that would be recognized by one of ordinary skill in the art. In addition, when describing embodiments of the present disclosure, the use of "may" refers to "one or more embodiments of the present disclosure." As used herein, the term "using" and variations thereof may be considered synonymous with the term "utilizing" and variations thereof, respectively. In addition, the term "exemplary" is intended to indicate an example or illustration.

[0202] In addition, any numerical range stated herein is intended to include all subranges of the same numerical precision contained within the stated range. For example, the range "1.0 to 10.0" is intended to include all subranges between the stated minimum value of 1.0 and the stated maximum value of 10.0 (and including the stated minimum value of 1.0 and the stated maximum value of 10.0), that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit stated herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit stated in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to amend this specification (including the claims) to explicitly state any subrange contained within the scope explicitly stated herein.

[0203] Although exemplary embodiments of the present disclosure have been described, it is understood that the present disclosure should not be limited to these exemplary embodiments, but that one skilled in the art can make various changes and modifications within the spirit and scope of the present disclosure as claimed.

Claims

1. A polycyclic compound, said polycyclic compound being represented by the following formula 3: Formula 3 In formula 3, R4 to R 19 are independently a hydrogen atom, a deuterium atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a naphthyl group, a phenanthryl group, and an anthracenyl group, and optionally R 12 and R 13 、R 13 and R 14 、R 14 and R 15 、R 16 and R 17 、R 17 and R 18 and R 18 and R 19 The groups in at least one pair thereof are bonded to each other to form a ring represented by any one of the following Formulae 4-1 to 4-4: In formula 4-1 to formula 4-4, R 20 、R 23 、R 25 and R 26 are independently a hydrogen atom, a deuterium atom and an alkyl group having 1 to 10 carbon atoms, R 21 、R 22 and R 24 are independently a hydrogen atom, a deuterium atom, an alkyl group having 1 to 10 carbon atoms, a phenyl group, a naphthyl group, a phenanthrenyl group, and an anthracenyl group, and "k" to "n" are each independently an integer from 0 to 4, Y1 and Y2 are each independently O or S, and R3 is a hydrogen atom, a deuterium atom, or an alkyl group having 1 to 10 carbon atoms.

2. The polycyclic compound according to claim 1, wherein R 13 and R 14 and R 17 and R 18 The groups in at least one pair thereof are bonded to each other to form a ring represented by Formula 4-2.

3. The polycyclic compound according to claim 1, wherein R4 to R 19 are independently a hydrogen atom, a deuterium atom, a methyl group, a tert-butyl group, a phenyl group, and a naphthyl group.

4. The polycyclic compound according to claim 1, wherein R3 is a hydrogen atom or a methyl group.

5. A polycyclic compound, which is any one of the compounds represented in the following compound group 1: Compound Group 1 6. An organic electroluminescent device, comprising: a first electrode; a hole transport region, located on the first electrode; an emission layer, located on the hole transport region; an electron transport region, located on the emission layer; as well as a second electrode, located on the electron transport region, 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, and Wherein, the emission layer comprises the polycyclic compound according to any one of claims 1 to 5.

7. The organic electroluminescent device according to claim 6, wherein: The emission layer is a delayed fluorescent emission layer including a host and a dopant, and The dopant includes the polycyclic compound.

8. The organic electroluminescent device according to claim 6, wherein: The emission layer is a thermally activated delayed fluorescent emission layer configured to emit blue light.

9. 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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