Organic electroluminescent devices

Abstract

This application discloses an organic electroluminescent device. The organic electroluminescent device of an embodiment includes a first electrode, a second electrode, and an emitting layer disposed between the first and second electrodes and comprising a polycyclic compound, wherein the polycyclic compound includes boron atoms; a first aromatic ring and a second aromatic ring, each directly bonded to a boron atom, an oxygen atom, or a sulfur atom, wherein the oxygen atom or sulfur atom is directly bonded to the boron atom; a third aromatic ring, directly bonded to an oxygen atom or a sulfur atom; a first connector connecting the first and second aromatic rings; and a second connector connecting the second and third aromatic rings, thereby exhibiting long lifetime characteristics and excellent color reproduction.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2019-0143525, filed on November 11, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] One or more aspects of embodiments of this disclosure relate to organic electroluminescent devices and polycyclic compounds used therein. Background Technology

[0004] Organic electroluminescent displays (OLEDs) are being actively developed as image displays. OLEDs are so-called self-emissive displays, in which holes and electrons injected from the first and second electrodes recombine in the emitting layer to generate excitons, and light is emitted through the transition of excitons from the excited state to the ground state, thereby achieving the display.

[0005] When applying organic electroluminescent devices to display devices, it is desirable to reduce the driving voltage of the organic electroluminescent devices and improve their emission efficiency and lifetime. Materials for organic electroluminescent devices that can stably achieve these requirements are desired.

[0006] To realize organic electroluminescent devices with long lifetimes, materials utilizing phosphorescence emission (which uses the energy of the triplet state), delayed fluorescence emission (which uses singlet excitons generated by collisions of triplet excitons according to triplet-triplet annihilation TTA), and / or thermally activated delayed fluorescence (TADF) phenomena are being developed. Summary of the Invention

[0007] One or more aspects of embodiments of this disclosure relate to organic electroluminescent devices exhibiting superior lifetime characteristics and / or superior emission efficiency.

[0008] One or more aspects of embodiments of this disclosure relate to polycyclic compounds as materials for organic electroluminescent devices having high color purity and / or long lifespan characteristics.

[0009] One or more exemplary embodiments of this disclosure provide an organic electroluminescent device comprising a first electrode, a second electrode disposed opposite the first electrode, and an emitting layer disposed between the first and second electrodes and comprising a polycyclic compound, wherein the polycyclic compound comprises boron atoms; a first aromatic ring and a second aromatic ring, each directly bonded to a boron atom, an oxygen atom, or a sulfur atom, wherein the oxygen atom or sulfur atom is directly bonded to the boron atom; a third aromatic ring, directly bonded to an oxygen atom or a sulfur atom; a first connector connecting the first and second aromatic rings; and a second connector connecting the second and third aromatic rings, wherein the first and second electrodes each independently comprise at least one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, In, Sn, and Zn, or a compound selected from two or more of them, a mixture selected from two or more of them, or an oxide thereof.

[0010] In this implementation, the first connector can be a direct connection, *-O-*, or *-NAr. a -*, and Ar a It can be 6 to 30 aryl groups, either substituted or unsubstituted, for cyclization of carbon atoms.

[0011] In the implementation, the second connector can be a direct connection, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr. b -*, and Ar b It can be 6 to 30 aryl groups, either substituted or unsubstituted, for cyclization of carbon atoms.

[0012] In the embodiments, the first to third aromatic rings may each be independently a substituted or unsubstituted benzene ring or a substituted or unsubstituted pyrimidine ring.

[0013] In one implementation, the emitting layer may emit delayed fluorescence.

[0014] In an implementation, the emitter layer may include a host and a dopant, and the dopant may include a polycyclic compound.

[0015] In the embodiments, the polycyclic compound can be represented by Formula 1:

[0016] Formula 1

[0017]

[0018] In Formula 1, X can be *-O-* or *-NAr4-*, Y can be *-O-* or *-S-*, Z can be directly connected, *-O-*, *-S-*, *-C(=O)-*, *-SO2-* or *-NAr5-*, Ar1 to Ar3 can each independently be an aromatic hydrocarbon ring with 6 to 30 substituted or unsubstituted carbon atoms for cyclization or an aromatic heterocycle with 2 to 30 substituted or unsubstituted carbon atoms for cyclization, and / or can be combined with adjacent groups to form a ring, Ar4 and Ar5 can each independently be an aryl group with 6 to 30 substituted or unsubstituted carbon atoms for cyclization or a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms for cyclization, and / or can be combined with adjacent groups to form a ring, and -* can indicate the connection position.

[0019] In the embodiments, the polycyclic compound represented by Formula 1 can be represented by Formula 1-1:

[0020] Equation 1-1

[0021]

[0022] In Formula 1-1, R1 to R3 may each independently be a hydrogen atom, a deuterium atom, an oxygen atom, a boron atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted nitro group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted heteroaryl group with 2 to 30 carbon atoms for cyclization, and / or may be combined with adjacent groups to form a ring, "a" and "c" may each independently be an integer selected from 0 to 4, "b" may be an integer selected from 0 to 3, and -*, X, Y, Z, Ar4 and Ar5 may each independently be the same as defined in Formula 1.

[0023] In the embodiments, the polycyclic compound represented by Formula 1 can be represented by Formula 1-2:

[0024] Formula 1-2

[0025]

[0026] In Equations 1-2, X1 and X2 can each independently be *-O-* or *-NAr4-*, Y1 and Y2 can each independently be *-O-* or *-S-*, Z1 and Z2 can each independently be directly connected, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr5-*, Ar 11 Ar 21 Ar 22 Ar 31 and Ar 32Each can be an aromatic hydrocarbon ring of 6 to 30 substituted or unsubstituted carbon atoms for cyclization, or an aromatic heterocycle of 2 to 30 substituted or unsubstituted carbon atoms for cyclization, and / or can be combined with adjacent groups to form a ring, and -*, Ar4 and Ar5 can each be the same as defined in Formula 1.

[0027] In the embodiments, the polycyclic compound represented by Formula 1 can be represented by one of Formulas 2-1 to 2-3:

[0028] Equation 2-1

[0029]

[0030] Equation 2-2

[0031]

[0032] Equation 2-3

[0033]

[0034] In equations 2-1 to 2-3, Y1 and Y2 can each independently be *-O-* or *-S-*, and Z1 and Z2 can each independently be directly connected, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr5-*, Ar 41 and Ar 42 Each group may be an aryl group, either substituted or unsubstituted, with 6 to 30 carbon atoms for cyclization, or a heteroaryl group, either substituted or unsubstituted, with 2 to 30 carbon atoms for cyclization, and / or may combine with adjacent groups to form a ring, R 11 R 21 R 22 R 31 and R 32 Each of the following groups may be independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted nitro group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted heteroaryl group with 2 to 30 carbon atoms for cyclization, and / or may be combined with adjacent groups to form a ring, "d" may be an integer selected from 0 to 2, "e" and "f" may each be independently an integer selected from 0 to 3, "g" and "h" may each be independently an integer selected from 0 to 4, and -* and Ar5 may be the same as defined in Formula 1.

[0035] In an embodiment, the polycyclic compound represented by Formula 1 may be represented by one of Formulas 3-1 to 3-3:

[0036] Equation 3-1

[0037]

[0038] Equation 3-2

[0039]

[0040] Equation 3-3

[0041]

[0042] In equations 3-1 to 3-3, X1 and X2 can each independently be *-O-* or *-NAr4-*, and Z1 and Z2 can each independently be directly connected, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr5-*, R 11 R 21 R 22 R 31 and R 32 Each of the following groups may be independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted nitro group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted heteroaryl group with 2 to 30 carbon atoms for cyclization, and / or may be combined with adjacent groups to form a ring. "d" may be an integer selected from 0 to 2, "e" and "f" may each be independently an integer selected from 0 to 3, "g" and "h" may each be independently an integer selected from 0 to 4, and -*, Ar4 and Ar5 may each be independently the same as defined in Formula 1.

[0043] In an embodiment, the polycyclic compound represented by Formula 1 may be represented by one of Formulas 4-1 to 4-3:

[0044] Equation 4-1

[0045]

[0046] Equation 4-2

[0047]

[0048] Equation 4-3

[0049]

[0050] In equations 4-1 to 4-3, X1 and X2 can each independently be *-O-* or *-NAr4-*, Y1 and Y2 can each independently be *-O-* or *-S-*, Ar 51 and Ar 52Each group may be an aryl group, either substituted or unsubstituted, with 6 to 30 carbon atoms for cyclization, or a heteroaryl group, either substituted or unsubstituted, with 2 to 30 carbon atoms for cyclization, and / or may combine with adjacent groups to form a ring, R 11 R 21 R 22 R 31 and R 32 Each of the following groups may be independently a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted nitro group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted heteroaryl group with 2 to 30 carbon atoms for cyclization, and may be combined with adjacent groups to form a ring. "d" may be an integer selected from 0 to 2, "e" and "f" may each be independently an integer selected from 0 to 3, "g" and "h" may each be independently an integer selected from 0 to 4, and -* and Ar4 may be the same as defined in Formula 1.

[0051] In the embodiments, the polycyclic compound represented by Formula 1 can be at least one selected from compounds represented in groups A to F:

[0052] Compound group A

[0053]

[0054]

[0055] Compound group B

[0056]

[0057]

[0058] Compound group C

[0059]

[0060] Compound group D

[0061]

[0062] Compound group E

[0063]

[0064]

[0065] Compound group F

[0066]

[0067] Attached Figure Description

[0068] The accompanying drawings are included to provide a further understanding of this disclosure, and are incorporated in and form a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the disclosure. In the drawings:

[0069] Figure 1 A schematic cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present disclosure;

[0070] Figure 2 A schematic cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present disclosure;

[0071] Figure 3 A schematic cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present disclosure; and

[0072] Figure 4 A schematic cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present disclosure. Detailed Implementation

[0073] This disclosure may have various modifications and may be embodied in different forms, and exemplary embodiments will be explained in detail with reference to the accompanying drawings. However, this disclosure may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, all modifications, equivalents, and substitutions that are included within the spirit and scope of this disclosure should be included herein.

[0074] It should be understood that when a component (or area, layer, part, etc.) is referred to as being "on", "connected to", or "attached to" another component, it may be directly on, directly connected to, or attached to the other component, or there may be an intermediate component.

[0075] The same reference numerals refer to the same elements throughout the drawings, and their repeated descriptions are not required. In the drawings, the thickness, scale, and dimensions of the constituent elements may be enlarged to effectively explain the technical content.

[0076] The term “and / or” includes any and all combinations of one or more of the related listed items.

[0077] It should be understood that although the terms “first,” “second,” etc., are used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. Therefore, without departing from the teachings of this disclosure, the first element may alternatively be referred to as the second element. Similarly, the second element may alternatively be referred to as the first element. Unless the context clearly indicates otherwise, the singular form used herein is intended to include the plural form as well.

[0078] Additionally, the terms "below," "under," "above," and "over" are used to explain the relationship between the elements shown in the accompanying drawings. These terms are relative concepts and are used based on the orientation shown in the drawings.

[0079] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the prior art and will not be interpreted in an ideal or overly formal sense unless expressly defined herein.

[0080] It should be further understood that when the terms “includes,” “including,” “comprises,” and / or “comprising” are used in this specification, they limit the presence of the described features, numbers, steps, operations, elements, parts, or combinations thereof, but do not exclude the presence or addition of one or more other features, numbers, steps, operations, elements, parts, or combinations thereof.

[0081] As used herein, expressions such as "at least one…", "a…", and "selected from…" modify the entire list of elements before a list of elements, but not individual elements within that list. Furthermore, when describing embodiments of this disclosure, the word "may" refers to "one or more embodiments of this disclosure".

[0082] In the following, an organic electroluminescent device according to an embodiment of the present disclosure will be explained with reference to the accompanying drawings.

[0083] Figures 1 to 4 This is a schematic cross-sectional view of an organic electroluminescent device according to an exemplary embodiment of the present disclosure. See also Figures 1 to 4 In the organic electroluminescent device 10 according to the embodiment, the first electrode EL1 and the second electrode EL2 are disposed opposite to each other, and the emission layer EML may be disposed between the first electrode EL1 and the second electrode EL2.

[0084] In addition to the emitter layer EML, the organic electroluminescent device 10 of the embodiment further includes a plurality of organic layers between the first electrode EL1 and the second electrode EL2. The plurality of organic layers may include a hole transport region HTR and an electron transport region ETR. For example, the organic electroluminescent device 10 of the embodiment may include a first electrode EL1, a hole transport region HTR, an emitter layer EML, an electron transport region ETR, and a second electrode EL2, which are stacked sequentially. In some embodiments, the organic electroluminescent device 10 of the embodiment may include a capping layer CPL disposed on the second electrode EL2.

[0085] The organic electroluminescent device 10 of the embodiments may include polycyclic compounds, as explained later, in a plurality of organic layers disposed between the first electrode EL1 and the second electrode EL2. For example, the polycyclic compounds of the embodiments may be included in the emitter layer EML and / or the electron transport region ETR. However, the embodiments of this disclosure are not limited thereto, and in addition to the emitter layer EML and the electron transport region ETR, the organic electroluminescent device 10 of the embodiments may include the polycyclic compounds of the embodiments in the hole transport region HTR (which is disposed in a plurality of organic layers between the first electrode EL1 and the second electrode EL2), or may include the polycyclic compounds of the embodiments in the capping layer CPL disposed on the second electrode EL2.

[0086] and Figure 1 Compare, Figure 2 A cross-sectional view of an organic electroluminescent device 10 according to an embodiment is shown, wherein the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL, and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL. Figure 1 Compare, Figure 3 A cross-sectional view of an organic electroluminescent device 10 according to 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. Figure 2 Compare, Figure 4 A cross-sectional view of an organic electroluminescent device 10 according to an embodiment is shown, which includes a capping layer CPL disposed on a second electrode EL2.

[0087] The first electrode EL1 may be conductive (e.g., it may be electrically conductive). The first electrode EL1 may be formed using a metal alloy or a conductive compound. The first electrode EL1 may be an anode. The first electrode EL1 may be a pixel electrode. The first electrode EL1 may be a transmissive electrode, a transmissive-reflective electrode, or a reflective electrode. When the first electrode EL1 is a transmissive electrode, it may be formed using a transparent metal oxide (e.g., indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO)). When the first electrode EL1 is a transmissive-reflective electrode or a reflective electrode, it may include silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), LiF, molybdenum (Mo), titanium (Ti), their compounds, or mixtures thereof (e.g., a mixture of Ag and Mg). In some embodiments, the first electrode EL1 may have a structure comprising multiple layers, including a reflective or transmissive layer formed using the aforementioned materials, and a transmissive conductive layer formed using ITO, IZO, ZnO, or ITZO. For example, the first electrode EL1 may include a three-layer structure of ITO / Ag / ITO. However, embodiments of this disclosure are not limited thereto. The thickness of the first electrode EL1 may be approximately [missing information]. to approximately For example, about to approximately

[0088] The hole transport region HTR is provided on the first electrode EL1. The hole transport region HTR may include at least one of a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer, and an electron blocking layer EBL. The thickness of the hole transport region HTR may be approximately [missing information]. to approximately

[0089] The hole transport region (HTR) may have a single layer formed using a single material, a single layer formed using multiple different materials, or a multilayer structure comprising multiple layers formed using multiple different materials.

[0090] 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 it may have a single-layer structure formed using a hole injection material or a hole transport material. In some embodiments, the hole transport region HTR may have a single-layer structure formed using a variety of different materials, or a structure stacked from the first electrode EL1: hole injection layer HIL / hole transport layer HTL, hole injection layer HIL / hole transport layer HTL / hole buffer layer, hole injection layer HIL / hole buffer layer, hole transport layer HTL / hole buffer layer, or hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL, but is not limited thereto.

[0091] Hole transport regions (HTRs) can be formed using any suitable method, such as vacuum deposition, spin coating, casting, Langmuir-Brookett (LB) method, inkjet printing, laser printing, and / or laser-induced thermal imaging (LITI).

[0092] Hole injection layer HIL may include, for example, phthalocyanine compounds (such as copper phthalocyanine), N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-phenyl-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-styrene). Sulfonates (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphor sulfonic acid (PANI / CSA), polyaniline / poly(4-styrene sulfonate) (PANI / PSS), N,N'-bis(1-naphth-1-yl)-N,N'-diphenyl-benzidine (NPB), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium [tetra(pentafluorophenyl)borate] and dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexaonitrile (HAT-CN).

[0093] Hole transport layers (HTLs) 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'-bis(1-naphth-1-yl)-N,N'-diphenyl-benzidine (NPB), 4,4'-cyclohexylbis[N,N-bis(4-methyl)phenyl]aniline (TAPC), 4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl (HMTPD), 1,3-bis(N-carbazolyl)benzene (mCP), etc.

[0094] The thickness of the hole transport region (HTR) can be approximately to approximately For example, about to approximately The thickness of the hole injection layer (HIL) can be, for example, approximately... to approximately Furthermore, the thickness of the hole transport layer (HTL) can be approximately [missing information]. to approximately For example, the thickness of the electron blocking layer (EBL) can be approximately to approximately When the thicknesses of the hole transport region (HTR), hole injection layer (HIL), hole transport layer (HTL), and electron blocking layer (EBL) meet the above ranges, satisfactory hole transport properties can be achieved without a significant increase in driving voltage.

[0095] In addition to the materials described above, the hole transport region (HTR) may further include a charge-generating material to improve conductivity. The charge-generating material may be substantially uniformly or non-uniformly dispersed within the hole transport region (HTR). The charge-generating material may be, for example, a p-dopant. The p-dopant may be a quinone derivative, a metal oxide, or a cyano-containing compound, but is not limited thereto. Non-limiting examples of p-dops include quinone derivatives (such as tetracyanoquinone dimethyl ether (TCNQ) and / or 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinone dimethyl ether (F4-TCNQ)), metal oxides (such as tungsten oxide and / or molybdenum oxide), etc.

[0096] As described above, in addition to the hole injection layer (HIL) and the hole transport layer (HTL), the hole transport region (HTR) may further include at least one of a hole buffer layer and an electron blocking layer (EBL). The hole buffer layer can compensate for the optical resonant distance according to the wavelength of light emitted from the emitter layer (EML) and can improve the light emission efficiency. Any material that may be included in the hole transport region (HTR) can be used in the hole buffer layer. The electron blocking layer (EBL) can prevent or reduce electrons injected from the electron transport region (ETR) into the hole transport region (HTR).

[0097] The emitter layer EML is provided on the hole transport region (HTR). The emitter layer EML may have, for example, approximately to approximately or about to approximately The thickness of the emitter layer (EML) is as follows. The emitter layer (EML) may be a single layer formed using a single material, a single layer formed using multiple different materials, or a multilayer structure with multiple layers formed using multiple different materials.

[0098] In the organic electroluminescent device 10 of the embodiment, the emission layer EML may include the polycyclic compound of the embodiment.

[0099] The polycyclic compound of the embodiments may include a boron atom; a first aromatic ring and a second aromatic ring, each directly connected to a boron atom, an oxygen atom, or a sulfur atom, wherein the oxygen atom or sulfur atom is directly connected to the boron atom; a third aromatic ring, which is directly connected to an oxygen atom or a sulfur atom; a first linker connecting the first aromatic ring and the second aromatic ring; and a second linker connecting the second aromatic ring and the third aromatic ring.

[0100] In the description, the term "substituted or unsubstituted" refers to the unsubstituted state or the state substituted by at least one substituent selected from the group consisting of: deuterium, halogen, cyano, nitro, amino, silyl, oxy, thio, sulfinyl (-S(=O)(H)), sulfonyl (-S(=O)₂H), carbonyl (-C(=O)H), boron, phosphine oxide, phosphine sulfide, alkyl, alkenyl, alkoxy, cycloalkyl, aryl, and heterocyclic. Furthermore, each of the substituents may be unsubstituted or further substituted. For example, biphenyl can be interpreted as aryl or a phenyl group substituted with a phenyl group.

[0101] In the description, the term "bonding with an adjacent group to form a ring" can refer to the formation of a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle by bonding with an adjacent group. The hydrocarbon ring can be an aliphatic or aromatic hydrocarbon ring. The heterocycle can be an aliphatic or aromatic heterocycle. The hydrocarbon ring and the heterocycle can each be a monocyclic or polycyclic ring independently. In some embodiments, the ring formed by bonding with an adjacent group can be further bonded with another ring to form a spirostructure.

[0102] In the description, the term "combined with adjacent groups to form a ring" can refer to the formation of a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle through the combination of two adjacent rings.

[0103] In the description, the term "adjacent group" may refer to a substituent on the same atom or point, a substituent on an atom directly attached to the base atom or point, or a substituent spatially positioned (e.g., within intramolecular bonding distance) relative to the nearest substituent. For example, in 1,2-dimethylbenzene, the two methyl groups can be interpreted as "adjacent groups" to each other, and in 1,1-diethylcyclopentane, the two ethyl groups can be interpreted as "adjacent groups" to each other.

[0104] In the description, the term "halogen atom" may refer to a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0105] In the description, the term "alkyl" may refer to a straight-chain or branched alkyl group. The number of carbon atoms in an alkyl group may be 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Non-limiting examples of alkyl groups 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-butyl 2-Hexyldecyl, 2-Octylide, n-Undecyl, n-Dodecyl, 2-Ethyldodecyl, 2-Butyldodecyl, 2-Hexyldodecyl, 2-Octylide, n-Tridecyl, n-Tetradecyl, n-Pentadedecyl, n-Hexadecyl, 2-Ethylhexadecyl, 2-Butylhexadecyl, 2-Hexylhexadecyl, 2-Octylide, n-Heptadedecyl, n-Octadedecyl, n-Nondecyl, n-Eicosyl, 2-Ethyleicosyl, 2-Butyleicosyl, 2-Hexyleicosyl, 2-Octylide, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, etc.

[0106] In this description, the term "hydrocarbon ring" may refer to any functional group or substituent optionally derived from an aliphatic hydrocarbon ring. The hydrocarbon ring may be a saturated hydrocarbon ring with 5 to 20 carbon atoms for cyclization.

[0107] In the description, the term "aryl" may refer to any functional group or substituent optionally derived from an aromatic hydrocarbon ring. The aryl group may be monocyclic or polycyclic. The number of carbons in the aryl group used to form the ring may be 6 to 30, 6 to 20, or 6 to 15. Non-limiting examples of aryl groups include phenyl, naphthyl, fluorenyl, anthracene, phenanthryl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, hexaphenyl, triphenylene, pyrene, benzofluoranthracene, 1,2-benzophenanthryl, etc.

[0108] In this description, the term "heterocyclic group" may refer to a functional group or substituent optionally derived from a ring comprising one or more boron (B), oxygen (O), nitrogen (N), phosphorus (P), silicon (Si), or sulfur (S) atoms as heteroatoms. Heterocyclic groups may be aliphatic or aromatic. Aromatic heterocyclic groups may be heteroaryl. Aliphatic and aromatic heterocycles may each be monocyclic or polycyclic.

[0109] When a heterocyclic group comprises two or more heteroatoms, the two or more heteroatoms may be the same or different. The heterocyclic group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group, and in some embodiments may be a heteroaryl group. The number of carbons in the ring used to form the heteroaryl group may be 2 to 30, 2 to 20, or 2 to 10.

[0110] The number of carbons in the ring used to form the aliphatic heterocyclic group can be 2 to 30, 2 to 20, or 2 to 10. Non-limiting examples of aliphatic heterocyclic groups include ethylene oxide, cyclothioethane, pyrrolidinyl, piperidinyl, tetrahydrofuranyl, tetrahydrothiophenyl, thiaalkyl, tetrahydropyranyl, 1,4-dioxane, etc.

[0111] When a heteroaryl group comprises two or more heteroatoms, the two or more heteroatoms may be the same or different. A heteroaryl group may be a monocyclic or polycyclic heterocyclic group. The number of carbon atoms in the ring used to form the heteroaryl group may be 2 to 30, 2 to 20, or 2 to 10. Non-limiting examples of heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridineyl, pyridazinyl, quinolinyl, quinazolinyl, quinoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazolopyrazinyl, isoquinolinyl, indolyl, carbazoleyl, N-arylcarbazoleyl, N-heteroarylcarbazoleyl, N-alkylcarbazoleyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazoleyl, benzothiaphenyl, dibenzothiaphenyl, thienothiaphenyl, benzofuranyl, phenanthrololinyl, thiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, thiadiazolyl, phenthiazolyl, dibenzothiazolyl, dibenzofuranyl, etc.

[0112] In the description, the term "thio" may refer to alkathio or arylthio, and the term "oxy" may refer to alkoxy or aryloxy. Alkoxy groups may include straight-chain, branched, or cyclic alkyl chains. The number of carbon atoms in an alkoxy group is not specifically limited, but may be, for example, 1 to 20 or 1 to 10. The number of carbon atoms in an aryloxy group is not specifically limited, but may be, for example, 6 to 30, 6 to 20, or 6 to 15. Non-limiting examples of oxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, pentoxy, hexoxy, octoxy, nonoxy, decoxy, benzyloxy, etc. However, embodiments of this disclosure are not limited thereto.

[0113] In the description, the number of carbon atoms in the amino group is not specifically limited, but can be from 1 to 30. The amino group can be alkylamino or arylamino. Non-limiting examples of amino groups include methylamino, dimethylamino, phenylamino, diphenylamino, naphthylamino, 9-methyl-anthraylamino, etc.

[0114] In the description, the alkyl group in the alkylamine group can be the same as the alkyl group exemplified above.

[0115] In the description, the aryl group in the arylamine group can be the same as the aryl group exemplified above.

[0116] In the description, the term "direct connection" may refer to a single key.

[0117] In the description, "-*" indicates the connection position.

[0118] In the polycyclic compounds of the embodiments, the first to third aromatic rings may each be independently a substituted or unsubstituted aromatic hydrocarbon ring with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted aromatic heterocycle with 2 to 30 carbon atoms for cyclization. For example, the first and second aromatic rings may each be independently a substituted or unsubstituted benzene ring. For example, the third aromatic ring may be a substituted or unsubstituted benzene ring or a substituted or unsubstituted pyrimidine ring.

[0119] In the polycyclic compound of the embodiments, the first linker may be a direct linker, *-O-*, or *-NAr. a -*。 Ar a It can be aryl groups, ranging from 6 to 30 substituted or unsubstituted carbon atoms used for cyclization. For example, Ar a It can be a substituted or unsubstituted phenyl group.

[0120] In the polycyclic compound of the embodiments, the second linker may be a direct linker, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr. b -*。 Ar bThe linker can be 6 to 30 aryl groups, either substituted or unsubstituted, for cyclization of the carbon atoms. For example, the second linker can be *-O-* or *-NAr. b -*.

[0121] In the polycyclic compounds of the embodiments, the first to third aromatic rings can each independently combine with adjacent rings to form a ring. For example, adjacent rings selected from two or more rings from the first to third aromatic rings can be directly combined or combined via linkers, or adjacent substituents can combine with each other to form a fused ring.

[0122] The emitting layer EML of the organic electroluminescent device 10 of the embodiment may include a polycyclic compound represented by Formula 1 of the embodiment:

[0123] Formula 1

[0124]

[0125] In Formula 1, Ar1 to Ar3 can each independently be an aromatic hydrocarbon ring with 6 to 30 substituted or unsubstituted carbon atoms for cyclization, or an aromatic heterocycle with 2 to 30 substituted or unsubstituted carbon atoms for cyclization, and / or can be combined with adjacent groups to form a ring. For example, Ar1 and Ar2 can each independently be a substituted or unsubstituted benzene ring. For example, Ar3 can be a substituted or unsubstituted benzene ring or a substituted or unsubstituted pyrimidine ring.

[0126] In Formula 1, X can be *-O-* or *-NAr4-*. In the polycyclic compounds of the embodiments, X can connect Ar1 ring and Ar2 ring to form a fused ring including boron atoms. In Formula 1, Y can be *-O-* or *-S-*. Z can be directly connected, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr5-*. In the polycyclic compounds of the embodiments, Y and Z can connect boron atoms, Ar2 ring, and Ar3 ring to form a fused ring. For example, Z can be directly connected, *-O-*, or *-NAr5-*. When Z is directly connected, adjacent Ar2 ring and Ar3 ring can be connected by a single bond.

[0127] In some embodiments, Ar4 and Ar5 may each be independently an aryl group with 6 to 30 substituted or unsubstituted carbon atoms for cyclization, or a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms for cyclization, and / or may be combined with adjacent groups to form a ring. For example, Ar4 may be an unsubstituted phenyl group. For example, Ar5 may be an unsubstituted phenyl group. In some embodiments, Ar5 may be combined with adjacent groups to form a ring, such as a carbazole group.

[0128] In the embodiments, the polycyclic compound represented by Formula 1 can be represented by Formula 1-1:

[0129] Equation 1-1

[0130]

[0131] Formula 1-1 is an example embodiment of Formula 1, wherein each of Ar1 to Ar3 is a substituted or unsubstituted benzene ring. In Formula 1-1, X, Y, Z, Ar4, and Ar5 may each be independently the same as those described for Formula 1.

[0132] In Formula 1-1, R1 to R3 may each independently be a hydrogen atom, a deuterium atom, an oxygen atom, a boron atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted nitro group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted heteroaryl group with 2 to 30 carbon atoms for cyclization, and / or may be combined with adjacent groups to form a ring. For example, R1 may be an oxygen atom or a boron atom. For example, R2 may be an alkyl group with 1 to 20 carbon atoms, particularly a methyl group. For example, R2 may be a substituted or unsubstituted amino group, and for example, an amino group in which two substituted or unsubstituted phenyl groups are attached to a nitrogen atom. For example, R2 may be a heteroaryl group with 2 to 30 carbon atoms for cyclization, for example, a carbazolyl group. For example, R3 may be a hydrogen atom. However, the embodiments disclosed herein are not limited thereto.

[0133] In Equation 1-1, "a" and "c" can each be an integer selected from 0 to 4, and "b" can be an integer selected from 0 to 3. When "a" to "c" are each an integer of 2 or greater, multiple R1 to R3 groups can be independently identical, or at least one of them can be different. For example, when "a" is an integer of 2 or greater, multiple R1 groups can be identical, or at least one of them can be different from the other groups. This is an illustrative example, and the same interpretation applies to R2 and R3 when each of "b" and "c" is an integer of 2 or greater.

[0134] In this embodiment, "a" can be 2. When "a" is 2, the two R1 groups can each be an oxygen atom or a boron atom independently. The two R1 groups can be the same or different. Accordingly, the polycyclic compound of this embodiment can include multiple structures. In some embodiments, the two R1 groups may combine with each other to form a ring. For example, the two R1 groups may combine with a benzene ring to form a fused ring.

[0135] In the embodiments, the polycyclic compound represented by Formula 1 can be represented by Formula 1-2:

[0136] Formula 1-2

[0137]

[0138] Formula 1-2 is an example implementation of Formula 1-1, where "a" is 2 and the two R1 groups are related to Ar. 21 Combined to form a ring. The polycyclic compounds of the embodiments may have properties related to Ar. 11 The symmetrical structure is shown in Equation 1-2.

[0139] In Equation 1-2, Ar 11 Ar 21 Ar 22 Ar 31 and Ar 32 Each can be an aromatic hydrocarbon ring, independently of substituted or unsubstituted carbon atoms for cyclic formation, consisting of 6 to 30 rings of aromatic hydrocarbons or substituted or unsubstituted carbon atoms of aromatic heterocycles for cyclic formation, and / or can be combined with adjacent groups to form a ring. For example, Ar 11 Ar 21 and Ar 22 Each can be a substituted or unsubstituted benzene ring independently. For example, Ar 31 and Ar 32 Each can be an independently substituted or unsubstituted benzene ring or a substituted or unsubstituted pyrimidine ring.

[0140] In formulas 1-2, X1 and X2 can each be independently *-O-* or *-NAr4-*. In the polycyclic compounds of the embodiments, X1 can be linked to Ar. 11 Ring and Ar 21 The ring is formed to create a fused ring including boron atoms. In the polycyclic compound of the embodiment, X2 may be linked to Ar. 11 Ring and Ar 22 The ring is formed to create a fused ring including boron atoms. In Formulas 1-2, Y1 and Y2 can each independently be *-O-* or *-S-*. Z1 and Z2 can each independently be directly connected, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr5-*. In the polycyclic compounds of the embodiments, Y1 and Z1 can be connected to boron atoms, Ar atoms, etc. 21 Ring and Ar 31 The rings can form fused rings. In the polycyclic compounds of the embodiments, Y2 and Z2 can be connected to boron atoms, Ar atoms, etc. 22 Ring and Ar 32 The rings form fused rings.

[0141] Ar4 and Ar5 can each be independently identical to those described for Equation 1.

[0142] In the embodiments, the polycyclic compounds represented by formula 1-2 can be represented by formula 1-3:

[0143] Formula 1-3

[0144]

[0145] Equations 1-3 are example implementations of Equations 1-2, where Ar 11 Ar 21 Ar 22 Ar 31 and Ar 32 Each is independently a substituted or unsubstituted benzene ring. In formulas 1-3, X1, X2, Y1, Y2, Z1, Z2, Ar4, and Ar5 can each be independently the same as those described for formulas 1-2.

[0146] In equation 1-3, R 11 R 21 R 22 R 31 and R 32 Each group may independently be a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted nitro group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted heteroaryl group with 2 to 30 carbon atoms for cyclization, and / or may be combined with adjacent groups to form a ring.

[0147] For example, R 11 It can be a hydrogen atom or a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms. In some embodiments, R 11 It can be an unsubstituted methyl group or an unsubstituted isopropyl group.

[0148] For example, R 21 and R 22 Each can be an independent hydrogen atom or a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, such as an unsubstituted methyl group. For example, R 21 and R 22 Each can be an independently substituted or unsubstituted amino group, such as a substituted or unsubstituted diphenylamino group. For example, R 21 and R 22 Each can be an independently substituted or unsubstituted heteroaryl group consisting of 2 to 30 carbon atoms for cyclization, such as an unsubstituted carbazolyl group.

[0149] For example, R 31 and R 32 Each atom can be an independent hydrogen atom. However, the embodiments disclosed herein are not limited thereto.

[0150] In equations 1-3, “d” can be an integer selected from 0 to 2. For example, “d” can be 0 or 1. “e” and “f” can each be an integer selected from 0 to 3 independently. For example, “e” and “f” can each be 0 or 1 independently. “g” and “h” can each be an integer selected from 0 to 4 independently. For example, “g” and “h” can each be 0 or 1 independently.

[0151] In the embodiments, the polycyclic compound represented by Formula 1 can be represented by one of Formulas 2-1 to 2-3:

[0152] Equation 2-1

[0153]

[0154] Equation 2-2

[0155]

[0156] Equation 2-3

[0157]

[0158] Equations 2-1 to 2-3 are example implementations of Equations 1-3, wherein X1 and X2 are each independently *-O-*, *—NAr 41 —* or *—NAr 42 —*. Equations 2-1 and 2-2 are exemplary implementations, where X1 and X2 are the same. In Equations 2-1 to 2-3, Y1, Y2, Z1, Z2, Ar5, R 11 R 21 R 22 R 31 R 32 The "d" through "h" can each be independently identical to those described for equations 1-2 and 1-3.

[0159] In equations 2-1 to 2-3, Ar 41 and Ar 42 Each group can be an aryl group, either substituted or unsubstituted, with 6 to 30 carbon atoms for cyclization, or a heteroaryl group, either substituted or unsubstituted, with 2 to 30 carbon atoms for cyclization, and / or can combine with adjacent groups to form a ring. For example, Ar... 41 and Ar 42 Each can be an aryl group, either substituted or unsubstituted, consisting of 6 to 30 substituted carbon atoms for cyclization. For example, Ar 41 and Ar 42 Each can be an unsubstituted phenyl group independently.

[0160] In an embodiment, the polycyclic compound represented by Formula 1 may be represented by one of Formulas 3-1 to 3-3:

[0161] Equation 3-1

[0162]

[0163] Equation 3-2

[0164]

[0165] Equation 3-3

[0166]

[0167] Equations 3-1 to 3-3 are example implementations of Equations 1-3, where Y1 and Y2 are each independently *-O-* or *-S-*. Equations 3-1 and 3-2 are example implementations, where Y1 and Y2 are the same. In Equations 3-1 to 3-3, X1, X2, Z1, Z2, Ar4, Ar5, R 11 R 21 R 22 R 31 R 32 The "d" through "h" can each be independently identical to those described for equations 1-2 and 1-3.

[0168] In an embodiment, the polycyclic compound represented by Formula 1 may be represented by one of Formulas 4-1 to 4-3:

[0169] Equation 4-1

[0170]

[0171] Equation 4-2

[0172]

[0173] Equation 4-3

[0174]

[0175] Equations 4-1 to 4-3 represent the following: Z1 and Z2 represent direct connection, *-O-*, and *—NAr, respectively. 51 —* or *—NAr 52 —* Case. In equations 4-1 to 4-3, X1, X2, Y1, Y2, Ar4, R 11 R 21 R 22 R 31 R 32 The "d" through "h" can each be independently identical to those described for equations 1-2 and 1-3.

[0176] In Equation 4-3, Ar 51 and Ar 52Each group can be an aryl group, either substituted or unsubstituted, with 6 to 30 carbon atoms for cyclization, or a heteroaryl group, either substituted or unsubstituted, with 2 to 30 carbon atoms for cyclization, and / or can combine with adjacent groups to form a ring. For example, Ar... 51 and Ar 52 Each can be an unsubstituted phenyl group independently. In some embodiments, Ar 51 and Ar 52 Each can independently combine with adjacent groups to form a ring, for example, a carbazole group.

[0177] The polycyclic compounds in the embodiments include direct bond structures between boron atoms (B) and oxygen atoms (O) or sulfur atoms (S). This allows the aromatic rings forming the polycyclic compound to crosslink and become fixed, thereby improving molecular stability. Accordingly, when the polycyclic compound of the embodiments is used as a material for the emitting layer of an organic electroluminescent device, the lifetime characteristics of the organic electroluminescent device can be improved.

[0178] In addition, the polycyclic compounds of the embodiments include multiple fused aromatic rings with boron atoms as centers, which allows multiple resonant molecular structures to be formed, and structural changes in the molecule can be minimized or reduced even in the excited state.

[0179] For example, the polycyclic compounds of the embodiments include BO bonds or BS bonds and have a molecular structure capable of forming multiple resonance structures, thereby exhibiting low ΔE. ST The value (the absolute value of the difference between the lowest excited singlet level S1 and the lowest excited triplet level T1) can be used as a material for thermally activated delayed fluorescence (TADF) and / or can emit light with a narrow full width at half maximum (FWHM) in the emission wavelength region.

[0180] The polycyclic compound represented by Formula 1 can be at least one compound selected from compounds represented in groups A to F:

[0181] Compound group A

[0182]

[0183]

[0184] Compound group B

[0185]

[0186]

[0187] Compound group C

[0188]

[0189] Compound group D

[0190]

[0191] Compound group E

[0192]

[0193]

[0194] Compound group F

[0195]

[0196]

[0197] The polycyclic compounds of the embodiments can be used as blue luminescent materials. For example, the polycyclic compounds according to the embodiments can be used as materials with a center wavelength (λ) of about 470 nm or less. max The polycyclic compound of the embodiment can be a blue luminescent material having a center wavelength of about 430 nm to about 470 nm. The polycyclic compound of the embodiment represented by Formula 1 can be a blue luminescent thermally activated delayed fluorescence dopant.

[0198] The polycyclic compounds of the embodiments can have stable molecular structures, wherein the aromatic rings are linked by BO or BS bonds, and can emit light with a narrow full width at half maximum (FWHM) due to the presence of multiple resonance structures. For example, the organic electroluminescent device 10 of the embodiments includes the polycyclic compounds of the embodiments in the emitting layer EML and can exhibit long lifetime characteristics and / or excellent color reproducibility.

[0199] In the organic electroluminescent device 10 of the embodiment, the emitting layer EML can emit delayed fluorescence. For example, the emitting layer EML can emit thermally activated delayed fluorescence (TADF).

[0200] In some embodiments, the organic electroluminescent device 10 of the embodiment may include multiple emission layers (EMLs). The multiple emission layers (EMLs) may be provided in a stacked configuration. For example, the organic electroluminescent device 10 including multiple emission layers (EMLs) may emit white light. In some embodiments, the organic electroluminescent device 10 including multiple emission layers (EMLs) may be an organic electroluminescent device having a series structure. When the organic electroluminescent device 10 includes multiple emission layers (EMLs), at least one emission layer (EML) may include a polycyclic compound of the embodiment.

[0201] In embodiments, the emission layer EML includes a host and a dopant, and may include a polycyclic compound as a dopant. For example, in the organic electroluminescent device 10 of an embodiment, the emission layer EML may include a host for emitting delayed fluorescence and a dopant for emitting delayed fluorescence, and may include a polycyclic compound as a dopant for emitting delayed fluorescence. The emission layer EML may include at least one of the polycyclic compounds represented in compound groups A to F as a thermally activated delayed fluorescence dopant.

[0202] In this embodiment, the emission layer EML may be a delayed fluorescence emission layer, and the emission layer EML may include any suitable host material and the polycyclic compound described in the above embodiments. For example, in this embodiment, the polycyclic compound may be used as a TADF dopant.

[0203] The polycyclic compound in the embodiments can be a thermally activated delayed fluorescence (TADF) host or a phosphorescent host. The emission layer EML of the polycyclic compound in the embodiments can emit phosphorescence or thermally activated delayed fluorescence. For example, the emission layer EML can emit thermally activated delayed fluorescence.

[0204] The emitter layer EML may include one (e.g., a structure) or two or more polycyclic compounds from the compound group.

[0205] In the organic electroluminescent device 10 of the embodiments, the emitting layer EML may comprise any suitable host material. For example, the emitting layer EML may comprise at least one of bis[2-(diphenylphosphine)phenyl]ether oxide (DPEPO), 4,4'-bis(carbazole-9-yl)biphenyl (CBP), 1,3-bis(carbazole-9-yl)benzene (mCP), 2,8-bis(diphenylphospho)dibenzo[b,d]furan (PPF), 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCTA), and 1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene (TPBi). However, the embodiments of this disclosure are not limited thereto. For example, tris(8-hydroxyquinoline)aluminum (Al) q3), poly(N-vinylcarbazole) (PVK), 9,10-bis(naphthyl-2-yl)anthracene (ADN), 3-tert-butyl-9,10-bis(naphthyl-2-yl)anthracene (TBADN), stilbene aromatic hydrocarbon (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethylbiphenyl (CDBP), 2-methyl-9,10-bis(naphthyl-2-yl)anthracene (MADN), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetrasiloxane (DPSiO4), etc., can be used as main materials.

[0206] In embodiments, the emitter layer (EML) may further comprise any suitable dopant material. In embodiments, the dopant material may include styrene derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styrene]stilbene (DPAVB) and N-(4-((E)-2-(6-((E)-4-(diphenylamino)styrene)naphth-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-dipyrenebenzene, 1,4-bis(N,N-diphenylamino)pyrene), etc.

[0207] In the organic electroluminescent device 10 of the embodiment, such as Figures 1 to 4 As shown, the electron transport region (ETR) is provided on the emitter layer (EML). The electron transport region (ETR) may include at least one of the electron blocking layer (HBL), the electron transport layer (ETL), and the electron injection layer (EIL). However, embodiments of this disclosure are not limited thereto.

[0208] The electronic transport region (ETR) may include a single layer formed using a single material, a single layer formed using multiple different materials, or a multilayer structure having multiple layers formed using multiple different materials.

[0209] 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 or an electron transport material. Furthermore, the ETR may have a single-layer structure containing multiple different materials, or a structure stacked from the emitter layer (EML): electron transport layer (ETL) / electron injection layer (EIL) or hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL), but is not limited to these. The thickness of the ETR can be, for example, approximately... to approximately

[0210] The electron transport region (ETR) can be formed using any suitable method, such as vacuum deposition, spin coating, casting, Langmuir-Brookett (LB) method, inkjet printing, laser printing and / or laser-induced thermal imaging (LITI).

[0211] When the electron transport region (ETR) includes an electron transport layer (ETL), the ETR may include anthracene compounds. The electron transport region may include, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 1,3,5-tris[(3-pyridyl)-benzene-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, and 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi). 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthyl-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole ( t Bu-PBD), bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinoline-10-hydroxy)beryllium (Bebq2), 9,10-bis(naphthyl-2-yl)anthracene (ADN), 1,3-bis[3,5-bis(pyridin-3-yl)phenyl]benzene (BmPyPhB), or mixtures thereof, but not limited thereto. The thickness of the electron transport layer (ETL) can be approximately to approximately And it can be, for example, about to approximately When the thickness of the electron transport layer (ETL) meets the above range, satisfactory electron transport properties can be obtained without a significant increase in driving voltage.

[0212] When the electron transport region (ETR) includes an electron injection layer (EIL), the ETR may include metal halides (such as LiF, NaCl, CsF, RbCl and / or RbI), lanthanides (such as ytterbium (Yb)), metal oxides (such as Li₂O and / or BaO), or lithium quinoline (8-hydroxy-quinoline lithium). However, embodiments of this disclosure are not limited thereto. The electron injection layer (EIL) may also be formed using a mixture of an electron transport material and an insulating organometallic salt. The insulating organometallic salt may be a material having a band gap of about 4 eV or higher. For example, the insulating organometallic salt may include metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates, or metal stearates. The thickness of the electron injection layer (EIL) may be approximately [missing information - likely a value]. to approximately or about to approximately When the thickness of the electron injection layer (EIL) meets the above range, satisfactory electron injection properties can be obtained without a significant increase in driving voltage.

[0213] The electron transport region (ETR) may include a hole blocking layer (HBL) as described above. 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). However, embodiments of this disclosure are not limited thereto.

[0214] The second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 can be a common electrode or a cathode. The second electrode EL2 can be a transmission electrode, a transmission-reflection electrode, or a reflection electrode. When the second electrode EL2 is a transmission electrode, the second electrode EL2 can include a transparent metal oxide, such as ITO, IZO, ZnO, ITZO, etc.

[0215] When the second electrode EL2 is a transmissive or reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, their compounds or mixtures thereof (e.g., a mixture of Ag and Mg). The second electrode EL2 may have a multilayer structure, including a reflective or transmissive layer formed using the above-mentioned materials, and a transmissive conductive layer formed using ITO, IZO, ZnO, ITZO, etc.

[0216] In some implementations, the second electrode EL2 may be connected to an auxiliary electrode. When the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may decrease.

[0217] In some embodiments, the capping layer CPL may be further disposed on the second electrode EL2 of the organic electroluminescent device 10 of the embodiment. The capping layer CPL may include, for example, α-NPD (N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'-diamine), NPB, TPD, m-MTDATA, Alq3, CuPc, N4,N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine (TPD15), 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCTA), etc.

[0218] In the organic electroluminescent device 10, during the application of voltage to the first electrode EL1 and the second electrode EL2, holes injected from the first electrode EL1 can move to the emitter layer EML through the hole transport region HTR, and electrons injected from the second electrode EL2 can move to the emitter layer EML through the electron transport region ETR. Electrons and holes can recombine in the emitter layer EML to generate excitons, and light can be emitted due to the transition of excitons from the excited state to the ground state.

[0219] The organic electroluminescent device 10 according to embodiments of the present disclosure includes a polycyclic compound of the embodiments in an emission layer EML disposed between a first electrode EL1 and a second electrode EL2, thereby exhibiting excellent emission efficiency and a narrow full width at half maximum (FWHM) in the blue light emission wavelength region. In some embodiments, the polycyclic compound of the embodiments can emit thermally activated delayed fluorescence, and the emission layer EML can include the polycyclic compound of the embodiments to emit thermally activated delayed fluorescence and exhibit high emission efficiency properties.

[0220] In some embodiments, the compound described in the embodiments may be included in the organic layers other than the emitting layer EML as a material for the organic electroluminescent device 10. For example, the organic electroluminescent device 10 according to embodiments of the present disclosure may include the compound in at least one functional layer disposed between the first electrode EL1 and the second electrode EL2 or in the capping layer CPL disposed on the second electrode EL2.

[0221] The polycyclic compounds of the embodiments may have stable molecular structures in which aromatic rings are bonded by BO or BS bonds, including multiple fused aromatic rings capable of forming multiple resonance structures, and have high lowest triplet excitation energy levels, and can accordingly be used as materials for delayed fluorescence emission. Furthermore, organic electroluminescent devices incorporating the polycyclic compounds of the embodiments in the emitting layer can emit blue light with a narrow full width at half maximum (FWHM) and exhibit long lifetime characteristics.

[0222] In the following description, the polycyclic compounds according to the embodiments and the organic electroluminescent devices according to the embodiments of this disclosure will be explained in particular with reference to and comparative embodiments. The embodiments are merely illustrative and are not intended to aid in understanding the present disclosure.

[0223] 1. Synthesis Example

[0224] Polycyclic compounds according to the embodiments can be synthesized, for example, as described below. However, the methods for synthesizing polycyclic compounds explained below are exemplary methods, and the methods for synthesizing polycyclic compounds according to the embodiments of this disclosure are not limited thereto.

[0225] A. Synthesize compound B-1

[0226] [Reaction 1]

[0227]

[0228] (1) Synthesis of intermediate compound B1

[0229] The mixture includes 2-methoxy-N-phenylaniline (27g), 3-bromophenol (20g), sodium butoxide (26g), Pd2(dba)3 (2g), and Ph ( t A toluene solution (350 mL) of Bu3 / BF4 (2.5 g) was heated and refluxed in an oil bath for approximately 3 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting mixture was separated by silica gel column chromatography to obtain 28 g (83% yield) of intermediate compound B1.

[0230] (2) Synthesis of intermediate compound B2

[0231] A DMSO (120 mL) solution comprising intermediate compound B1 (28 g), 1,3-diiodobenzene (14.4 g), potassium carbonate (26.6 g), copper iodide (0.4 g), and ferric acetylacetone (III) (1.5 g) was heated and stirred at approximately 150 °C for approximately 15 hours. After cooling to room temperature, the reaction solution was decanted into water. The target material was extracted with ethyl acetate, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting mixture was separated by silica gel column chromatography to obtain 23 g (80% yield) of intermediate compound B2.

[0232] (3) Synthesis of compound B-1

[0233] A 1M boron tribromide solution in heptane (17.5 mL) was added to a solution of 1,2-dichlorobenzene (100 mL) including the intermediate compound B2 (5 g) obtained above under ice-cooling conditions. After the addition was complete, the reaction mixture was heated and stirred at approximately 80 °C for approximately 20 hours. After cooling to room temperature, N,N-diisopropylethylamine (6 mL) was added, followed by stirring. The reaction solvent was removed by distillation under reduced pressure. The resulting mixture was separated by silica gel column chromatography to obtain 2 g (40% yield) of the target material. The molecular weight of the target material was determined to be 644 using FAB-MS. The resulting compound B-1 was further separated by sublimation and used as a sample for evaluation. The emission wavelength of compound B-1 was evaluated to be approximately 453 nm by measuring the emission spectrum of the instrument.

[0234] B. Synthesis of compound D-1

[0235] [Reaction 2]

[0236]

[0237] (1) Synthesis of intermediate compound D1

[0238] The mixture includes 2-methoxy-N-phenylaniline (10g), 3,5-dibromophenol (20g), sodium butoxide (13g), Pd2(dba)3 (1g), and Ph ( t A 200 mL solution of Bu3 / BF4 (1.3 g) in toluene was heated and refluxed in an oil bath for approximately 3 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting mixture was separated by silica gel column chromatography to obtain 13 g (70% yield) of the intermediate compound D1.

[0239] (2) Synthesis of intermediate compound D2

[0240] The mixture includes intermediate compound D1 (13g), diphenylaniline (7.1g), sodium butoxide (13g), Pd2(dba)3 (1g), and Ph ( t A 200 mL solution of Bu3 / BF4 (1.3 g) in toluene was heated and refluxed in an oil bath for approximately 3 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting mixture was separated by silica gel column chromatography to obtain 13 g (81% yield) of the intermediate compound D2.

[0241] (3) Synthesis of compound D-1

[0242] The target compound D-1 was obtained by reacting intermediate compound D2 with 1,3-diiodobenzene, followed by the reaction of intermediate compound D3 with boron tribromide as in the synthesis example B-1. The molecular weight of the target material was determined to be 978 using FAB-MS. The resulting compound was further separated by sublimation and used as a sample for evaluation.

[0243] The emission wavelength of compound D-1 was assessed to be approximately 450 nm by measuring the emission spectrum of the device.

[0244] C. Synthesis of compound E-12

[0245] [Reaction 3]

[0246]

[0247] (1) Synthesis of intermediate compound E1

[0248] The mixture will include 3,5-dibromo-N,N-diphenylaniline (20g), aniline (3.7g), sodium butoxide (6g), Pd2(dba)3 (0.5g), and Ph ( tA 200 mL solution of Bu3 / BF4 (0.7 g) in toluene was heated and refluxed in an oil bath for approximately 3 hours. After cooling to room temperature, the reaction solution was poured into water. The target material was extracted with toluene, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting mixture was separated by silica gel column chromatography to obtain 13 g (78% yield) of the intermediate compound E1.

[0249] (2) Synthesis of intermediate compound E2

[0250] A mixture of toluene (200 mL) and water (70 mL) comprising intermediate compound E1 (13 g), (2-(tert-butylthio)phenyl)boronic acid (8.5 g), potassium carbonate (11 g), and Pd(PPh3)4 (0.5 g) was heated at approximately 80 °C for approximately 24 hours. After cooling to room temperature, the reaction solution was decanted into water. The target material was extracted with toluene, dried over magnesium sulfate, and concentrated under reduced pressure. The resulting mixture was separated by silica gel column chromatography to obtain 9.6 g (62% yield) of intermediate compound E2.

[0251] (3) Synthesis of compound E-12

[0252] The target compound E-12 was obtained by reacting intermediate compound E2 with 1,3-diiodobenzene, followed by the reaction of intermediate compound E3 with boron tribromide as in the synthesis example B-1. The molecular weight of the target material was determined to be 978 using FAB-MS. The resulting compound was further separated by sublimation and used as a sample for evaluation. The emission wavelength of compound E-12 was evaluated to be approximately 460 nm by measuring the emission spectrum of the instrument.

[0253] 2. Evaluate the energy levels of the compound.

[0254] The luminescence properties of the organic electroluminescent devices of the embodiments, which include polycyclic compounds of the embodiments in the emitting layer, are evaluated using the methods described below. A method for manufacturing the organic electroluminescent device used for device evaluation is described below.

[0255] Organic electroluminescent devices of Examples 1 to 3 were fabricated using polycyclic compounds B-1, D-1, and E-12 as dopant materials for the emission layer, respectively. Organic electroluminescent devices of Comparative Example 1 and Comparative Example 2 were fabricated using comparative compounds C1 and C2 as dopant materials for the emission layer, respectively.

[0256] The compounds used as dopant materials in Examples 1 to 3, and Comparative Examples 1 and 2 are as follows.

[0257] Table 1

[0258]

[0259]

[0260] Manufacturing of organic electroluminescent devices

[0261] On the glass substrate, there will be approximately The ITO layer was patterned to a thickness of approximately [thickness value] and washed with ultrapure water, ultrasonically cleaned, exposed to UV for approximately 30 minutes, and treated with ozone to form the first electrode. Then, HAT-CN was deposited to approximately [thickness value value]. The thickness of α-NPD is deposited to approximately [amount missing]. And deposit mCP to approximately The thickness is increased to form a hole transport region.

[0262] Then, the polycyclic compound or comparative compound of the embodiment is co-deposited with the host material at a ratio of 6:94 to form approximately A layer of thickness is formed to create an emission layer. For example, co-deposited emission layers are formed by mixing compounds B-1, D-1, and E-12 with the host materials of Examples 1 to 3, respectively, or by mixing comparative compounds C1 and C2 with the host materials of Comparative Examples 1 and 2, respectively. mCP is used as the host material for co-deposition in the emission layer.

[0263] Subsequently, on the emitter layer, DPEPO was used to form approximately A layer of approximately [thickness value] was formed using TPBi. A layer of approximately [thickness value], and the formation of a layer with approximately [thickness value] using LiF. A layer of approximately [thickness value missing] is formed to create an electron transport region. Then, aluminum (Al) is used to form a layer with approximately [thickness value missing]. The second electrode has a thickness of [missing information].

[0264] In this embodiment, a vacuum deposition apparatus is used to form a hole transport region, an emitter layer, an electron transport region, and a second electrode.

[0265] Compounds of functional layers

[0266]

[0267] Evaluation of the properties of organic electroluminescent devices

[0268] Table 2 shows the evaluation results of the organic electroluminescent devices of Examples 1 to 3, Comparative Example 1, and Comparative Example 2. Table 2 compares and displays the full width at half maximum (FWHM) and maximum emission wavelength (λ) of the organic electroluminescent devices thus fabricated. max ) and device lifespan. As shown in Table 2, in the evaluation results of the embodiments and comparative examples, the maximum emission wavelength (λ) maxThe value corresponds to the maximum value in the emission spectrum, and the device lifetime is shown as a relative value for Comparative Example 1 (which is set to 100%).

[0269] Table 2

[0270] Classification Doped materials Full width at half maximum (nm) <![CDATA[λ max (nm)]]> Device lifespan (%) Example 1 Compound B-1 35 453 130 Example 2 Compound D-1 34 450 143 Example 3 Compound E-12 30 460 157 Comparative Example 1 Compare compounds C1 18 467 100 Comparative Example 2 Compare compound C2 67 448 82

[0271] Referring to the results in Table 2, it can be determined that the organic electroluminescent devices of Examples 1 to 3 emit light in the blue wavelength region of about 470 nm or less, and the emitted light has a narrow full width at half maximum (FWHM) of less than about 40 nm. Furthermore, it can be observed that the organic electroluminescent devices of Examples 1 to 3, which include the polycyclic compounds of the embodiments, exhibit excellent device lifetime characteristics. In contrast, in Comparative Example 1, the aromatic rings are linked together, exhibiting a cross-linked structure. Accordingly, a narrow FWHM of about 18 nm is observed. Without being bound by any theoretical or interpretative correctness, it is considered that the device lifetime characteristics of Comparative Compound C1 are inferior to those of the Examples because it does not contain BO or BS direct bonds. In Comparative Example 2, a polycyclic compound with a structure including BO direct bonds was used, but Comparative Compound C2 does not have multiple resonant molecular structures. Accordingly, a large FWHM value and poor device characteristics are observed.

[0272] Unbound by the correctness of any theory or explanation, it is believed that: because the polycyclic compounds in the embodiments include the direct bond portion of BO or BS, the combined fused rings stabilize the molecular structure and contribute to improving the long-lifetime characteristics of the device. Furthermore, because the polycyclic compounds possess multiple resonant molecular structures, the molecular structure remains stable even in the excited state, and light with a narrow full width at half maximum (FWHM) can be emitted.

[0273] The organic electroluminescent device of the embodiment includes the polycyclic compound of the embodiment in the emitting layer, thereby emitting light with a narrow full width at half maximum (FWHM) and having excellent color properties and improved lifetime characteristics.

[0274] The organic electroluminescent device according to the embodiments of this disclosure can achieve a long lifespan.

[0275] The polycyclic compounds according to embodiments of this disclosure can be applied to organic electroluminescent devices to achieve long lifespan.

[0276] As used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation rather than as terms of degree, and are intended to explain the inherent biases of measurements or calculations that would be recognized by one of ordinary skill in the art.

[0277] Any numerical ranges listed herein are intended to include all subranges with the same numerical precision included within the listed ranges. For example, the range “1.0 to 10.0” is intended to include all subranges between the listed minimum value of 1.0 and the listed maximum value of 10.0 (inclusive), that is, subranges having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limit listed herein is intended to include all lower numerical limits included therein, and any minimum numerical limit listed in this specification is intended to include all higher numerical limits included therein. Therefore, the applicant reserves the right to amend this specification (including the claims) to expressly list any subranges included within the scope expressly listed herein.

[0278] Although exemplary embodiments of this disclosure have been described, it will be understood that this disclosure is not to be limited to these exemplary embodiments, but rather that various changes and modifications can be made by those skilled in the art within the spirit and scope of this disclosure as set forth in the appended claims and their equivalents.

Claims

1. An organic electroluminescent device, comprising: First electrode; A second electrode positioned relative to the first electrode; as well as An emission layer disposed between the first electrode and the second electrode. The first electrode and the second electrode each independently comprise at least one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, In, Sn, and Zn, or a compound selected from two or more of them, a mixture selected from two or more of them, or an oxide thereof. The emission layer comprises a polycyclic compound represented by Formula 1: Formula 1 In Equation 1, X is either *-O-* or *-NAr4-*. Y is either *-O-* or *-S-*. Z represents direct connection, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr5--*. Ar1 to Ar3 are each independently an aromatic hydrocarbon ring with 6 to 30 substituted or unsubstituted carbon atoms for cyclic formation, or an aromatic heterocycle with 2 to 30 substituted or unsubstituted carbon atoms for cyclic formation, and / or combined with adjacent groups to form a ring. Ar4 and Ar5 are each independently an aryl group with 6 to 30 substituted or unsubstituted carbon atoms for cyclization, or a heteroaryl group with 2 to 30 substituted or unsubstituted carbon atoms for cyclization, and / or combined with adjacent groups to form a ring. -* indicates the connection location.

2. The organic electroluminescent device of claim 1, wherein the polycyclic compound represented by formula 1 is represented by formula 1-1: Equation 1-1 In Equation 1-1, R1 to R3 are each independently a hydrogen atom, a deuterium atom, an oxygen atom, a boron atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted nitro group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted heteroaryl group with 2 to 30 carbon atoms for cyclization, and / or combined with adjacent groups to form a ring. a and c are each an independent integer selected from 0 to 4. b is an integer selected from 0 to 3, and -*, X, Y, Z, Ar4, and Ar5 are each independently identical to those defined in Equation 1.

3. The organic electroluminescent device of claim 1, wherein the polycyclic compound represented by formula 1 is represented by formulas 1-2: Formula 1-2 In equation 1-2, X1 and X2 are each independently *-O-* or *-NAr4-*. Y1 and Y2 are each independently *-O-* or *-S-*. Z1 and Z2 are each independently a direct connection, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr5-*. Ar 11 Ar 21 Ar 22 Ar 31 and Ar 32 Each is an aromatic hydrocarbon ring, independently of substituted or unsubstituted, consisting of 6 to 30 cyclic carbon atoms or an aromatic heterocycle, independently of substituted or unsubstituted, consisting of 2 to 30 cyclic carbon atoms, and / or combined with adjacent groups to form a ring. Ar4 and Ar5 are each independently identical to those defined in Equation 1.

4. The organic electroluminescent device of claim 1, wherein the polycyclic compound represented by formula 1 is represented by one of formulas 2-1 to 2-3: Equation 2-1 Equation 2-2 Equation 2-3 Among them, in equations 2-1 to 2-3, Y1 and Y2 are each independently *-O-* or *-S-*. Z1 and Z2 are each independently a direct connection, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr5-*. Ar 41 and Ar 42 Each aryl group is independently substituted or unsubstituted with 6 to 30 carbon atoms for cyclization, or substituted or unsubstituted with 2 to 30 carbon atoms for cyclization, and / or combined with adjacent groups to form a ring. R 11 R 21 R 22 R 31 and R 32 Each group is independently composed of a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted nitro group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted heteroaryl group with 2 to 30 carbon atoms for cyclization, and / or combined with adjacent groups to form a ring. d is an integer selected from 0 to 2. e and f are each an independent integer selected from 0 to 3. g and h are each independent integers selected from 0 to 4, and -* and Ar5 are the same as those defined in Equation 1.

5. The organic electroluminescent device of claim 1, wherein the polycyclic compound represented by formula 1 is represented by one of formulas 3-1 to 3-3: Equation 3-1 Equation 3-2 Equation 3-3 Among them, in equations 3-1 to 3-3, X1 and X2 are each independently *-O-* or *-NAr4-*. Z1 and Z2 are each independently a direct connection, *-O-*, *-S-*, *-C(=O)-*, *-SO2-*, or *-NAr5-*. R 11 R 21 R 22 R 31 and R 32 Each group is independently composed of a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted nitro group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted heteroaryl group with 2 to 30 carbon atoms for cyclization, and / or combined with adjacent groups to form a ring. d is an integer selected from 0 to 2. e and f are each an independent integer selected from 0 to 3. g and h are each independent integers selected from 0 to 4, and Ar4 and Ar5 are each independently identical to those defined in Equation 1.

6. The organic electroluminescent device of claim 1, wherein the polycyclic compound represented by formula 1 is represented by one of formulas 4-1 to 4-3: Equation 4-1 Equation 4-2 Equation 4-3 Among them, in equations 4-1 to 4-3, X1 and X2 are each independently *-O-* or *-NAr4-*. Y1 and Y2 are each independently *-O-* or *-S-*. Ar 51 and Ar 52 Each aryl group is independently substituted or unsubstituted with 6 to 30 carbon atoms for cyclization, or substituted or unsubstituted with 2 to 30 carbon atoms for cyclization, and / or combined with adjacent groups to form a ring. R 11 R 21 R 22 R 31 and R 32 Each group is independently composed of a hydrogen atom, a deuterium atom, a cyano group, a substituted or unsubstituted amino group, a substituted or unsubstituted nitro group, a substituted or unsubstituted alkyl group with 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group with 1 to 20 carbon atoms, a substituted or unsubstituted aryl group with 6 to 30 carbon atoms for cyclization, or a substituted or unsubstituted heteroaryl group with 2 to 30 carbon atoms for cyclization, and / or combined with adjacent groups to form a ring. d is an integer selected from 0 to 2. e and f are each an independent integer selected from 0 to 3. g and h are each independently an integer selected from 0 to 4, and -* and Ar4 are the same as those defined in Equation 1.

7. The organic electroluminescent device of claim 1, wherein the polycyclic compound represented by formula 1 is at least one selected from compounds represented in groups A to F: Compound group A Compound group B Compound group C Compound group D Compound group E Compound group F 8. The organic electroluminescent device of claim 1, wherein the emitting layer emits delayed fluorescence.

9. The organic electroluminescent device of claim 1, wherein the emitting layer comprises a host and a dopant, and the dopant comprises the polycyclic compound represented by Formula 1.

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