Organic electroluminescence device and polycyclic compound for organic electroluminescence device

Abstract

An organic electroluminescence device and a polycyclic compound for an organic electroluminescence device are provided. The organic electroluminescence device includes a first electrode; a second electrode on the first electrode; and a plurality of organic layers between the first electrode and the second electrode, wherein a polycyclic compound represented by Formula 1-1 or Formula 1-2 is included in at least one of the plurality of organic layers. The polycyclic compound is represented by Formula 1-1 or Formula 1-2.

Description

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2018-0151038, filed on November 29, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0002] Embodiments of this disclosure relate to an organic electroluminescent device and a polycyclic compound for use in an organic electroluminescent device. Background Technology

[0003] Organic electroluminescent display devices are being actively developed as image display devices. Unlike liquid crystal displays, organic electroluminescent display devices are so-called self-emissive display devices, in which holes and electrons injected from the first electrode and the second electrode recombine in the emitting layer and emit light as a luminescent material of an organic compound included in the emitting layer to achieve display.

[0004] Examples of organic electroluminescent devices (e.g., organic devices) may include: a first electrode; a hole transport layer located on the first electrode; an emission layer located on the hole transport layer; an electron transport layer located on the emission layer; and a second electrode located on the electron transport layer. Holes are injected from the first electrode, and the injected holes move through the hole transport layer and are injected into the emission layer. Conversely, electrons are injected from the second electrode, and the injected electrons move through the electron transport layer and are injected into the emission layer. Holes and electrons injected into the emission layer recombine, thereby generating excitons in the emission layer. Organic electroluminescent devices emit light by using the light generated when the excitons fall back (e.g., transition or relax) to the ground state.

[0005] When applying organic light-emitting devices to display devices, organic light-emitting devices with low driving voltage, high luminous efficiency and long lifetime have always been advantageous. Therefore, the development of materials for organic light-emitting devices that can stably achieve the required performance has been investigated. Summary of the Invention

[0006] Embodiments of this disclosure provide an organic electroluminescent device and a polycyclic compound for use in the organic electroluminescent device.

[0007] Embodiments of this disclosure provide an organic electroluminescent device, comprising: a first electrode; a second electrode located on the first electrode; and a plurality of organic layers located between the first electrode and the second electrode, wherein the first electrode and the second electrode each independently comprise at least one selected from the following substances: Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti; a composite selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti; a mixture selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti; and a transparent metal oxide, wherein at least one of the organic layers may comprise a polycyclic compound represented by Formula 1-1 or Formula 1-2:

[0008] Equation 1-1

[0009]

[0010] Formula 1-2

[0011]

[0012] In Formula 1-1, R1 to R3 can each be independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, or can be combined with adjacent groups to form a condensed polycyclic ring, and l to n can each be independently an integer from 0 to 4.

[0013] X1 can be B or N, and X2 can be BR. 1-1 or NR 1-2 R 1-1 and R 1-2 Each of the following can be independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms.

[0014] The subscript a can be 1 or 2, Y1 can be O, S, BR4 or NR5, and R4 and R5 can each be independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms, or can be combined with adjacent groups to form a condensed polycyclic ring.

[0015] At least one of R1 to R5 can be incorporated into an adjacent group to form a condensed polycyclic ring with a BN direct bond, or it can be a heteroaryl group with a BN direct bond.

[0016] In Formulas 1-2, X3 and X4 can each be independently B or N, Y2 to Y4 can each be independently BR6, NR7, O, or S, and R6 and R7 can each be independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms. For example, R6 and R7 can be unsubstituted phenyl groups.

[0017] R8 can be a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. The subscript b can be an integer from 0 to 15, Z can be B or N, and c can be 0 or 1.

[0018] In the embodiments, the polycyclic compound may be represented by formula 2-1-1 or formula 2-1-2:

[0019] Equation 2-1-1

[0020]

[0021] Equation 2-1-2

[0022]

[0023] In equations 2-1-1 and 2-1-2, X 2-1 and X 2-2 Each can be independently designated as BR 1-1 or NR 1-2 And R1 to R3, l to n, X1, Y1, R 1-1 and R 1-2 It can be the same as that defined in Equation 1-1.

[0024] In the embodiments, the polycyclic compound may be represented by formula 3-1-1 or formula 3-1-2:

[0025] Formula 3-1-1

[0026]

[0027] Equation 3-1-2

[0028]

[0029] In Equations 3-1-1 and 3-1-2, NR 1-2-1 and NR 1-2-2 Each can be independently NR 1-2 And R1 to R3, l to n, R 1-2 R5 can be the same as that defined in Equation 1-1.

[0030] In the embodiments, the polycyclic compound can be represented by formula 4-1:

[0031] Equation 4-1

[0032]

[0033] In Equation 4-1, R1 to R3, l to n, X2 and a can be the same as those defined in Equation 1-1.

[0034] In the embodiments, the polycyclic compound can be represented by formulas 2-2-1 to 2-2-3:

[0035] Equation 2-2-1

[0036]

[0037] Equation 2-2-2

[0038]

[0039] Equation 2-2-3

[0040]

[0041] In Equations 2-2-1 to 2-2-3, X3, X4, and Y2 to Y4 can be the same as those defined in Equation 1-2.

[0042] In an embodiment, two or three of the X3, X4 and Y2 to Y4 selected from Equations 1-2 may include B.

[0043] In the embodiments, the organic layer may include: a hole transport region located on the first electrode; an emission layer located on the hole transport region; and an electron transport region located on the emission layer, wherein the emission layer may include a polycyclic compound.

[0044] In one embodiment, the emitting layer may include a host and a dopant, the dopant possibly comprising a polycyclic compound. The emitting layer may be configured to emit blue light in the wavelength range of 440 nm to 490 nm. In another embodiment, the polycyclic compound may be a thermally activated delayed fluorescence dopant.

[0045] In the embodiments, the polycyclic compound may include at least one of the compounds represented in compound group 1.

[0046] Embodiments of this disclosure provide a polycyclic compound, which is represented by Formula 1-1 or Formula 1-2 above. Attached Figure Description

[0047] The accompanying drawings are included to provide a further understanding of the subject matter of this disclosure, and are incorporated in and form a part of this specification. The drawings illustrate exemplary embodiments of this disclosure and, together with the description, serve to explain the principles of this disclosure. In the drawings:

[0048] Figure 1 This is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure;

[0049] Figure 2 This is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure; and

[0050] Figure 3 This is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure. Detailed Implementation

[0051] The subject matter of this disclosure can be modified in various ways and can be implemented in different forms, and exemplary embodiments will be explained in more detail with reference to the accompanying drawings. However, the subject matter of this disclosure can be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, all modifications, equivalents, and substitutions that fall within the spirit and scope of this disclosure should be included herein.

[0052] The same reference numerals always refer to the same elements. In the drawings, the dimensions of the structures may be exaggerated for clarity. 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 used only to distinguish one element from another. Thus, without departing from the spirit and scope of this disclosure, a first element may be referred to as a second element. Similarly, a second element may be referred to as a first element. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well.

[0053] In this specification, it should be understood that the terms "comprising" or "having" are intended to indicate that a particular feature, number, function, operation, element, part or combination thereof may be present, without excluding the possibility of the presence or addition of other features, numbers, functions, operations, elements, parts or combinations thereof.

[0054] In this specification, when a layer, film, region, plate, etc., is referred to as being "on" or "above" another part, the layer, film, region, plate, etc., may be "directly on" said other part, or intermediate layers may be present. Conversely, when a layer, film, region, plate, etc., is referred to as being "below" or "under" another part, the layer, film, region, plate, etc., may be "directly below" said other part, or intermediate layers may be present. Furthermore, the term "on" in this specification can include both the case of being on a lower part and the case of being on a higher part. Additionally, it will be understood that when an element or layer is referred to as being "between" two elements or layers, the element or layer may be the only element or layer between the two elements or layers, or one or more intermediate elements or layers may be present.

[0055] In this specification, the term "substituted or unsubstituted" corresponds to either unsubstituted or substituted with at least one substituent selected from the group consisting of deuterium, halogen, cyano, nitro, amino, hydroxyl, silyl, boron, phosphonyl oxide, phosphonyl sulfide, alkyl, alkenyl, alkoxy, aryloxy, alkylthio, arylthio, alkylcycloyl, aryl, and heterocyclic groups. Furthermore, each substituent can be substituted or unsubstituted. For example, biphenyl can be interpreted as aryl or phenyl substituted with a phenyl group.

[0056] In this specification, the phrase "forming a ring via bonding with adjacent groups" can mean forming a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle via bonding with adjacent groups. The hydrocarbon ring may include aliphatic hydrocarbon rings and / or aromatic hydrocarbon rings. The heterocycle may include aliphatic heterocycles and / or aromatic heterocycles. The ring formed by bonding with adjacent groups can be monocyclic and / or polycyclic. Furthermore, a ring formed by bonding with each other can bond with another ring to form a spirostructure.

[0057] In this specification, the term "adjacent group" can mean a substituent that directly substitutes for an atom of a corresponding substituent, another substituent that substitutes for an atom of a corresponding substituent, or a substituent located spatially closest to the corresponding substituent. For example, in 1,2-dimethylbenzene, the two methyl groups can be interpreted as "adjacent groups" to each other, and in 1,2-diethylcyclopentene, the two ethyl groups can be interpreted as "adjacent groups" to each other.

[0058] In this specification, alkyl groups can be straight-chain, branched, or cyclic. The number of carbon atoms in an alkyl group can range from 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of alkyl groups 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-Octydecyl, undecyl, dodecyl, 2-Ethyldodecyl, 2-Butyldodecyl, 2-Hexyldodecyl, 2-Octydecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, 2-Ethylhexadecyl, 2-Butylhexadecyl, 2-Hexylhexadecyl, 2-Octydecyl, heptadecanyl, octadecyl, nonadecanyl, eicosyl, 2-Ethyleicosyl, 2-Butyleicosyl, 2-Hexyleicosyl, 2-Octydecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, hexadecyl, octadecyl, nonadecanyl, triadecyl, etc., without limitation.

[0059] In this specification, the term "aryl" refers to an optional functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group can be monocyclic or polycyclic. The number of cyclic carbon atoms in the aryl group can be 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups include phenyl, naphthyl, fluorenyl, anthraceneyl, phenanthryl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, hexaphenyl, benzo[9,10]phenanthryl, pyrene, benzofluoranthracene, etc. Basic, without restrictions.

[0060] In this specification, a heteroaryl group can be a heteroaryl group comprising one or more of O, N, P, Si, and S as heteroatoms for cyclization. When a heteroaryl group comprises at least two heteroatoms, the at least two heteroatoms can be the same or different from each other. The heteroaryl group can be a monocyclic heteroaryl group or a polycyclic heteroaryl group. The number of cyclizing carbon atoms in the heteroaryl group can be 2 to 30, 2 to 20, or 2 to 10. Examples of heteroaryl groups may include thienyl, furanyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridineyl, pyridazinyl, quinolinyl, quinazolinyl, quinoxazinyl, phenothiazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolinyl, indolyl, carbazoleyl, N-arylcarbazoleyl, N-heteroarylcarbazoleyl, N-alkylcarbazoleyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazoleyl, benzothiazolyl, benzothiaphenyl, dibenzothiaphenyl, thiaphenothiaphenyl, benzofuranyl, phenanthrolinel, isoxazolyl, thiadiazolyl, phenothiazinyl, dibenzothiaryl, dibenzofuranyl, etc., without limitation.

[0061] In this specification, the term "direct linkage" may refer to a single bond.

[0062] Figure 1 This is a schematic cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure. The organic electroluminescent device 10 according to 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 sequentially stacked.

[0063] and Figure 1 compared to, 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. Additionally, with Figure 1 compared to, 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.

[0064] At least one organic layer in the hole transport region (HTR), emitter layer (EML), and electron transport region (ETR) may comprise a polycyclic compound represented by Formula 1-1 or Formula 1-2. Further description of the polycyclic compound represented by Formula 1-1 or Formula 1-2 will be provided below.

[0065] The first electrode EL1 may be conductive (e.g., electrically conductive). The first electrode EL1 may be formed of a metal alloy or a conductive compound. The first electrode EL1 may be an anode. Alternatively, 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 include a transparent metal oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium tin zinc oxide (ITZO). When the first electrode EL1 is a transmissive-reflective electrode or a reflective electrode, it may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a composite or mixture thereof (e.g., a mixture of Ag and Mg). In some embodiments, the first electrode EL1 may have a structure comprising multiple layers, said multiple layers including a reflective or transmissive-reflective layer formed of any of the described materials and a transparent conductive layer formed of ITO, IZO, ZnO, or ITZO. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but this disclosure is not limited thereto. The thickness of the first electrode EL1 may be approximately to For example, about to

[0066] The hole transport region HTR can be located on the first electrode EL1. The hole transport region HTR can include at least one of the hole injection layer HIL, hole transport layer HTL, hole buffer layer and electron blocking layer EBL.

[0067] The hole transport region (HTR) can have the following structures: a single layer formed of a single material; a single layer formed of multiple different materials; or a multilayer having multiple layers formed of multiple different materials.

[0068] For example, the hole transport region HTR can have a monolayer structure as a hole injection layer HIL or a hole transport layer HTL, or it can have a monolayer structure formed of a hole injection material and a hole transport material. In some embodiments, the hole transport region HTR can have a monolayer structure formed of multiple different materials, or it can have a structure in which 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 are sequentially stacked from the first electrode EL1, but this disclosure is not limited thereto.

[0069] Hole transport regions (HTRs) can be formed using a variety of suitable methods such as vacuum deposition, spin coating, casting, Langmuir-Blodget (LB) methods, inkjet printing, laser printing, and / or laser-induced thermal imaging (LITI).

[0070] Hole injection layers (HILs) can include, for example, phthalocyanine compounds (such as copper phthalocyanine), N,N'-bis[4-di(m-tolyl)-aminophenyl]-N-N'-diphenyl-biphenyl-4,4'-diamine (DNTPD), 4,4',4"-tris[(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4"-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tris[2-naphthyl(phenyl)amino]triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate). (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphor sulfonic acid (PANI / CSA), polyaniline / poly(4-styrene sulfonate) (PANI / PSS), N,N'-bis(1-naphthyl)-N,N'-diphenylbenzidine (NPB), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetra(pentafluorophenyl)borate or dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexaonitrile (HAT-CN), etc.

[0071] Hole transport layers (HTLs) may also include, for example, carbazole derivatives (such as N-phenylcarbazole or polyvinylcarbazole), fluorene derivatives, triphenylamine derivatives (such as N,N'-bis(3-methylphenyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (TPD) or 4,4',4”-tris(N-carbazolyl)triphenylamine (TCTA)), N,N'-bis(1-naphthyl)-N,N'-diphenylbenzidine (NPB), 4,4'-cyclohexylene-bis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl (HMTPD) or 1,3-bis(N-carbazolyl)benzene (mCP), etc.

[0072] The thickness of the hole transport region HTR can be approximately to For example, about to The thickness of the hole injection layer (HIL) can be, for example, approximately to The thickness of the hole transport layer (HTL) can be approximately to For example, the thickness of the electron blocking layer (EBL) can be approximately to When the thicknesses of the hole transport region (HTR), hole injection layer (HIL), hole transport layer (HTL), and electron blocking layer (EBL) meet the described ranges, suitable or satisfactory hole transport performance can be achieved without significantly increasing the driving voltage.

[0073] In addition to the materials described, the hole transport region HTR may also include a charge-generating material to improve conductivity. The charge-generating material may be uniformly or non-uniformly dispersed in the hole transport region HTR. The charge-generating material may be, for example, a p-doper. The p-doper may be one of quinone derivatives, metal oxides, and cyano-containing compounds, but this disclosure is not limited thereto. Non-limiting examples of p-dopers may be, for example, quinone derivatives (such as tetracyanoquinone dimethyl (TCNQ) or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinone dimethyl (F4-TCNQ)) or metal oxides (such as tungsten oxide or molybdenum oxide), but this disclosure is not limited thereto.

[0074] As described here, in addition to the hole injection layer (HIL) and the hole transport layer (HTL), the hole transport region (HTR) may also include at least one of a hole buffer layer and an electron blocking layer (EBL). The hole buffer layer can improve luminous efficiency by compensating for the resonant distance according to the wavelength of light emitted from the emitter layer (EML). The material included in the hole transport region (HTR) can also be used as the material included in the hole buffer layer. The electron blocking layer (EBL) can be a layer that prevents or reduces the injection of electrons from the electron transport region (ETR) into the hole transport region (HTR).

[0075] The emitter layer EML can be located on the hole transport region HTR. The emitter layer EML can have, for example, approximately to or about to The thickness of the emitter layer (EML) is as follows: a single layer formed of a single material; a single layer formed of multiple different materials; or a multilayer having multiple layers formed of multiple different materials.

[0076] The emitter layer EML may include a polycyclic compound represented by formula 1-1 or formula 1-2:

[0077] Equation 1-1

[0078]

[0079] Formula 1-2

[0080]

[0081] In Formula 1-1, R1 to R3 can each be independently a hydrogen atom, a deuterium atom, an alkyl group, an aryl group, or a heteroaryl group, or they can be combined with adjacent groups to form a condensed polycyclic ring. In this specification, the condensed polycyclic ring can comprise: a substituted or unsubstituted condensed polycyclic ring; or a substituted or unsubstituted condensed heterocyclic ring.

[0082] The alkyl group can be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, the aryl group can be a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, and the heteroaryl group can be a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. R1 to R3 can each be independently bonded to a hydrogen atom or an adjacent group to form a condensed polycyclic ring.

[0083] Subscripts l to n can all be independent integers from 0 to 4. For example, all l to n can be 0, or at least one of l to n can be 1 or greater. When at least one of l to n is 1 or greater, at least one of R1 to R3 can be not a hydrogen atom.

[0084] When l to n are all independently 1 or greater, R1 to R3 can be the same or different from each other.

[0085] When l is 2 or greater, multiple R1s can be the same or different from each other. The descriptions of m and n are essentially the same as those of l provided above, so their repeated descriptions will not be repeated here.

[0086] Equation 1-1 can be represented by, for example, equation A1 or equation A2:

[0087] Formula A1

[0088]

[0089] Formula A2

[0090]

[0091] Formula A1 is such that when l is 2, the two R1s of Formula 1-1 combine with each other to form an unsubstituted condensed heteropentacyclic ring with a BN direct bond. Formula A2 is such that when l and n are both 2, the two R1s and two R3s of Formula 1-1 combine with each other to form an unsubstituted condensed heterotetracyclic ring with a BN direct bond. However, this disclosure is not limited thereto; R1 to R3 can combine with each other to form various suitable condensed polycyclic rings. For example, substituted or unsubstituted condensed polycyclic rings with both aromatic and non-aromatic rings can be formed, or substituted or unsubstituted condensed heteropolycyclic rings with both aromatic and non-aromatic rings can be formed. In Formulas A1 and A2, pentacyclic and tetracyclic rings are formed respectively, but this disclosure is not limited thereto. For example, condensed polycyclic rings with two or more but less than ten rings can be formed. In the following description, when the phrase "forming a condensed polycyclic ring via combination with an adjacent group" is used, the same description as above may be applied.

[0092] X1 can be B or N. For example, X1 can be B.

[0093] X2 can be BR 1-1 or NR 1-2 For example, X2 can be NR. 1-2 .

[0094] R 1-1 and R 1-2 Each of them can be independently a hydrogen atom, a deuterium atom, an alkyl group, an aryl group, or a heteroaryl group.

[0095] The alkyl group can be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, the aryl group can be a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, and the heteroaryl group can be a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. For example, R 1-1 and R 1-2 It can be a substituted or unsubstituted aryl group, and for example, it can be an unsubstituted phenyl group.

[0096] The subscript 'a' can be 1 or 2. When 'a' is 2, X2 can be the same as or different from each other. For example, when 'a' is 2, all X2 can be NR. 1-2 For example, all X2 groups can be aniline.

[0097] Y1 can be O, S, BR4, or NR5. For example, Y1 can be NR5.

[0098] R4 and R5 can each be independently a hydrogen atom, a deuterium atom, an alkyl group, an aryl group, or a heteroaryl group, or they can be combined with adjacent groups to form a condensed polycyclic ring.

[0099] The alkyl group can be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, the aryl group can be a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, and the heteroaryl group can be a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. For example, R5 can be a substituted or unsubstituted aryl group, and can be an unsubstituted phenyl group, for example. For example, Y1 can be an aniline group.

[0100] At least one of R1 to R5 can be bonded to an adjacent group to form a condensed polycyclic ring with a BN direct bond, or a heteroaryl group with a BN direct bond. For example, R1 can be bonded to at least one of R2 to R5 and X2 to form a condensed polycyclic ring with a BN direct bond. The descriptions of R2 to R5 are substantially the same as those of R1 as provided above, and therefore will not be repeated here.

[0101] In some embodiments, for example, when l is 2 or greater, R1 may combine with each other to form a condensed polycyclic ring, or may combine with at least one of a plurality of R1, R2 to R5 and X2 to form a condensed polycyclic ring with BN direct bonds. The descriptions of n and m are substantially the same as those of l as provided above, and therefore their repeated descriptions will not be repeated here.

[0102] In some embodiments, at least one of R1 to R3 may be incorporated into an adjacent group to form a condensed polycyclic ring with a BN direct bond, or at least one of R4 and R5 may be a polycyclic heteroaryl group with a BN direct bond.

[0103] Equation 1-1 can be expressed by Equation 2-1-1 or Equation 2-1-2:

[0104] Equation 2-1-1

[0105]

[0106] Equation 2-1-2

[0107]

[0108] Equations 2-1-1 and 2-1-2 are expressions in which the substitution position of X2 in equation 1-1 and a are specifically defined. In equations 2-1-1 and 2-1-2, X 2-1 and X 2-2 Each can be independently designated as BR 1-1 or NR 1-2 And R1 to R3, l to n, X1, Y1, R 1-1 and R 1-2 It can be the same as that described with respect to Equation 1-1.

[0109] Equation 1-1 can be expressed by Equation 3-1-1 or Equation 3-1-2:

[0110] Formula 3-1-1

[0111]

[0112] Equation 3-1-2

[0113]

[0114] Equations 3-1-1 and 3-1-2 are the substitution positions of X2 in equation 1-1 and the equations in which X1, Y1, and a are specifically defined. In equations 3-1-1 and 3-1-2, R 1-2-1 and R 1-2-2 Each can be independently R 1-2 And R1 to R3, l to n, R 1-2 R5 can be the same as that described with respect to Equation 1-1.

[0115] Equation 1-1 can be represented by Equation 4-1:

[0116] Equation 4-1

[0117]

[0118] Equation 4-1 is the one in which X1 and Y1 of Equation 1-1 are specifically defined. In Equation 4-1, R1 to R3, l to n, X2 and a can be the same as those described with respect to Equation 1-1.

[0119] In Equation 1-2, X3 and X4 can both be B or N independently. For example, X3 and X4 can both be B or both can be N, or X3 or X4 can be B and the other can be N.

[0120] Y2 to Y4 can each be independently BR6, NR7, O, or S.

[0121] R6 and R7 can each independently be a hydrogen atom, a deuterium atom, an alkyl group, an aryl group, or a heteroaryl group. The alkyl group can be a substituted or unsubstituted alkyl group having 1 to 30 (e.g., 1 to 20) carbon atoms, the aryl group can be a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, and the heteroaryl group can be a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. For example, R6 and R7 can each independently be a substituted or unsubstituted aryl group. In some embodiments, R6 and R7 can each independently be an unsubstituted phenyl group.

[0122] One to four atoms selected from X3, X4, and Y2 to Y4 may contain B. For example, two or three atoms selected from X3, X4, and Y2 to Y4 may contain B. In this case, the other atoms may each independently contain N, O, or S. For example, two or three atoms selected from X3, X4, and Y2 to Y4 may contain B and the others may contain N, or two or three atoms selected from X3, X4, and Y2 to Y4 may contain B and the others, except for X3 and X4, may contain O, or two or three atoms selected from X3, X4, and Y2 to Y4 may contain B and the others, except for X3 and X4, may contain S.

[0123] R8 can be a hydrogen atom, a deuterium atom, an alkyl group, an aryl group, or a heteroaryl group. The alkyl group can be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, the aryl group can be a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, and the heteroaryl group can be a substituted or unsubstituted heteroaryl group having 2 to 30 cyclic carbon atoms. For example, R8 can be hydrogen.

[0124] The subscript b can be an integer from 0 to 15. When b is 1 or greater, R8 may not be hydrogen. When b is 2 or greater, multiple R8s may be the same or different from each other.

[0125] Z can be B or N. The subscript c can be 0 or 1.

[0126] On the other hand, in this specification, "------" can indicate an optional key. In Equation 1-2, for example, when c is 0, it can indicate that the key is omitted, and when c is 1, it can indicate that the key is connected to Z by direct connection or single key connection.

[0127] Equation 1-2 can be expressed by Equations 2-2-1 to 2-2-3:

[0128] Equation 2-2-1

[0129]

[0130] Equation 2-2-2

[0131]

[0132] Equation 2-2-3

[0133]

[0134] Equations 2-2-1 to 2-2-3 are those in which R8, b, Z, and c of equation 1-2 are specifically defined. Equation 2-2-1 is the equation in which b and c of equation 1-2 are 0. Equation 2-2-2 is the equation in which b, c, and Z of equation 1-2 are 0, 1, and B, respectively. Equation 2-2-3 is the equation in which b, c, and Z of equation 1-2 are 0, 1, and N, respectively. In equations 2-2-1 to 2-2-3, X3, X4, and Y2 to Y4 can be the same as those described with respect to equation 1-2. In the specification, the statement "b is 0" can have substantially the same meaning as "b is 1 or greater" and all R8 are hydrogen.

[0135] The polycyclic compound in the embodiments can be any of the compounds shown in compound group 1:

[0136] Compound group 1

[0137]

[0138]

[0139]

[0140]

[0141] The emitter layer EML may include one, two, or more polycyclic compounds as described herein. In addition to the polycyclic compounds described herein, the emitter layer EML may also include any suitable material available in the art.

[0142] The emitter layer (EML) may include a host and a dopant, and the dopant may comprise a polycyclic compound. Polycyclic compounds represented by Formulas 1-1 and 1-2 may be included as dopants in the emitter layer EML. Polycyclic compounds represented by Formulas 1-1 and 1-2 may also be included as thermally activated delayed fluorescence dopants in the emitter layer EML.

[0143] The emission layer EML can emit any of red, green, and blue light using polycyclic compounds, including those described in the embodiments. For example, the emission layer EML can be a blue emission layer configured to emit blue light with a wavelength range of about 490 nm or less. In some embodiments, the polycyclic compound can be included in the emission layer EML as a blue light dopant, which is configured to emit light with a wavelength range of about 440 nm to 490 nm or about 465 nm to 475 nm.

[0144] The emitter layer (EML) may include a host and dopants, and may include any suitable material available in the art as the host material without limitation. For example, it may include at least one of bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), 4,4'-bis(carbazole-9-yl)biphenyl (CBP), 1,3-bis(carbazole-9-yl)benzene (mCP), 2,8-bis(diphenylphosphino)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, this disclosure is not limited thereto; for example, tris(8-hydroxyquinoline)aluminum (Alq3), poly( The main materials include n-vinylcarbazole (PVK), 9,10-bis(naphthyl-2-yl)anthracene (ADN), 2-tert-butyl-9,10-bis(naphthyl-2-yl)anthracene (TBADN), stilbene arylene (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), or octaphenylcyclotetrasiloxane (DPSiO4).

[0145] The emitter layer (EML) may also include, for example, N,N,N',N'-tetraphenyl-pyrene-1,6-diamine (TPD), 4,4'-bis[2-(9-ethyl-9H-carbazole-3-yl)vinyl]-1,1'-biphenyl; 4,4'-bis(9-ethyl-3-carbazole-vinyl)-1,1'-biphenyl (BCzVBi), 10-phenyl-10H,10'H-spiro[acridin-9,9'-anthracene]-10'-one (ACR). SA), 3,4,5,6-tetra-9H-carbazole-9-yl-1,2-phenylenedionitrile (4CzPN), 2,4,5,6-tetra-9H-carbazole-9-yl-isophthalonitrile (4CzIPN), bis[4-(9,9-dimethyl-9,10-dihydroacrylidine)phenyl] sulfone (DMAC-DPS) and 2-phenoxazine-4,6-diphenyl-1,3,5-triazine (PSZ-TRZ) as dopants. In addition, the emitter layer EML may also include styrene derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styrene]benzene (DPAVB) or 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)) or pyrene and its derivatives (e.g., 1,1-dipyrene, 1,4-dipyrenebenzene or 1,4-bis(N,N-diphenylamino)pyrene) as suitable dopant materials.

[0146] The emission layer EML can be a blue emission layer configured to emit blue light. The emission layer EML can be a fluorescent emission layer configured to emit fluorescence. The emission layer EML can be a delayed fluorescence emission layer configured to emit delayed fluorescence. For example, the emission layer EML can be a thermally activated delayed fluorescence emission layer configured to emit thermally activated delayed fluorescence.

[0147] exist Figures 1 to 3 In the organic electroluminescent device 10 of the embodiment shown, the electron transport region (ETR) is located on the emitter layer (EML). The electron transport region (ETR) may include at least one of the hole blocking layer (HBL), the electron transport layer (ETL), and the electron injection layer (EIL), but this disclosure is not limited thereto.

[0148] The electronic transport region (ETR) can have the following structures: a single layer formed of a single material; a single layer formed of multiple different materials; or a multilayer having multiple layers formed of multiple different materials.

[0149] For example, the electron transport region (ETR) can have a monolayer structure as an electron injection layer (EIL) or an electron transport layer (ETL), or it can have a monolayer structure formed of an electron injection material and an electron transport material. In some embodiments, the ETR can have a monolayer structure formed of multiple different materials, or it can have a structure of electron transport layer (ETL) / electron injection layer (EIL) or hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL) stacked sequentially from the emitter layer (EML), but this disclosure is not limited thereto. The thickness of the ETR can be, for example, approximately to Within the range.

[0150] Electron transport regions (ETRs) can be formed using various suitable methods such as vacuum deposition, spin coating, casting, Langmuir-Blodget (LB) methods, inkjet printing, laser printing, or laser-induced thermal imaging (LITI).

[0151] When the electron transport region ETR includes an electron transport layer ETL, the electron transport region ETR may include anthracene compounds. However, this disclosure is not limited thereto, and the electron transport region ETR may include, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 1,3,5-tris[(3-pyridyl)-benzyl-3-yl]benzene, 2,4,6-tris(3'-(pyridyl-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-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 (tBu-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), or mixtures thereof. The thickness of the electron transport layer (ETL) can be approximately... to For example, about to When the thickness of the electron transport layer (ETL) meets the described range, suitable or satisfactory electron transport performance can be achieved without significantly increasing the driving voltage.

[0152] When the electron transport region (ETR) includes an electron injection layer (EIL), the ETR can use: lanthanide metals, such as Yb; metal halides, such as RbCl, RbI, LiF, NaCl, and CsF; metal oxides, such as Li₂O and BaO; or lithium 8-hydroxyquinoline (LiQ), etc., but this disclosure is not limited thereto. The EIL can also be formed from a mixture of an electron transport material and an insulating organometallic salt. The organometallic salt can be a material having a band gap of about 4 eV or greater. For example, the organometallic salt can include, for example, metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates, or metal stearates. The thickness of the EIL can be approximately... to or about to When the thickness of the electron injection layer (EIL) meets the described range, suitable or satisfactory electron injection performance can be achieved without significantly increasing the driving voltage.

[0153] The electron transport region (ETR) may include a hole blocking layer (HBL) as described above. The hole blocking layer (HBL) may include at least one of, for example, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and 4,7-diphenyl-1,10-phenanthroline (Bphen), but this disclosure is not limited thereto.

[0154] The second electrode EL2 is located 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, it can be formed of a transparent metal oxide (e.g., indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO), etc.).

[0155] 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 / Ca, LiF / Al, Mo, Ti, or a composite or mixture thereof (e.g., a mixture of Ag and Mg). In some embodiments, the second electrode EL2 may be a structure having multiple layers, including a reflective or transmissive layer formed of the described material and a transparent conductive layer formed of ITO, IZO, ZnO, or ITZO.

[0156] In some embodiments, the second electrode EL2 can be coupled to the auxiliary electrode. When the second electrode EL2 is coupled to the auxiliary electrode, the resistance of the second electrode EL2 can be reduced.

[0157] In some embodiments, the capping layer may be further located on the second electrode EL2 of the organic electroluminescent device 10 of the embodiment. The capping layer may include, for example, α-NPD, 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) and / or N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB), etc.

[0158] In addition to the emitter layer (EML), the polycyclic compound described above may be included as a material in the organic layer for use in the organic electroluminescent device 10. The organic electroluminescent device 10 according to embodiments of this disclosure may include a polycyclic compound in at least one organic layer between the first electrode EL1 and the second electrode EL2 and / or in a capping layer located on the second electrode EL2.

[0159] In the organic electroluminescent device 10, when a voltage is applied to the first electrode EL1 and the second electrode EL2, holes injected from the first electrode EL1 can move to the emitter layer EML via the hole transport region HTR, and electrons injected from the second electrode EL2 can move to the emitter layer EML via the electron transport region ETR. Electrons and holes can recombine in the emitter layer EML to generate excitons, and when the excitons fall back from the excited state (e.g., through transition or relaxation) to the ground state, the excitons can emit light.

[0160] According to embodiments of this disclosure, an organic electroluminescent device 10 with low driving voltage and high efficiency can be realized.

[0161] According to embodiments of this disclosure, polycyclic compounds can be applied to organic electroluminescent devices to help reduce driving voltage and improve efficiency.

[0162] According to embodiments of this disclosure, the energy difference between the singlet and triplet states of the polycyclic compound can be 0.3 eV or less, or 0.25 eV or less, thus the polycyclic compound can be used as a thermally activated delayed fluorescence material. According to embodiments of this disclosure, the polycyclic compound can be used as a material for organic electroluminescent devices, thereby contributing to improved efficiency.

[0163] In the following sections, polycyclic compounds according to embodiments of the present disclosure and organic electroluminescent devices comprising the polycyclic compounds of the embodiments will be explained in more detail with reference to examples and comparative examples. Furthermore, the following examples are merely illustrative to aid in understanding the present disclosure, and the scope of the disclosure is not limited thereto.

[0164] Synthesis Example

[0165] Polycyclic compounds according to embodiments of the present disclosure can be synthesized (e.g., as described in the examples below). However, the methods for synthesizing polycyclic compounds according to embodiments of the present disclosure are not limited thereto.

[0166] 1-1 Synthesis of compound TA-01

[0167] The polycyclic compound TA-01 according to embodiments of the present disclosure can be synthesized, for example, by the following reaction 1:

[0168] Reaction 1

[0169]

[0170] Synthesis of intermediate A

[0171] Pd₂(dba)₃ (0.03 eq), (t-Bu)₃P (0.06 eq), NaOt-Bu (1 eq), and toluene (0.1 M, based on 1 eq reagent) were added to a flask containing 2-chloro-N₁,N₁,N₃-triphenylphenyl-1,3-diamine (1 eq) and 11-bromodibenzo[c,e]dibenzo[3,4:5,6][1,2]azaboron[1,2-a][1,2]azaborane (1.2 eq), and the mixture was refluxed and stirred for 5 hours. The mixture was then cooled to room temperature, extracted with MC (dichloromethane), and washed with distilled water. The extracted solution was dried over anhydrous MgSO₄ and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain intermediate A (yield 77.64%). The [M]⁺ value of intermediate A, as measured by high-resolution mass spectrometry, was 697.

[0172] Synthesis of compound TA-01

[0173] 0.1 M tert-butylbenzene (based on 1 eq reagent) was added to a flask containing intermediate A (1 eq), and the mixture was cooled to -78 °C. After 1 hour, n-butyllithium (n-BuLi) (1.2 eq) was added, and the mixture was warmed to room temperature. Subsequently, BBr3 (1.2 eq) and N,N-diisopropylethylamine (DIPEA) (2 eq) were added, and the resulting mixture was stirred at room temperature for 13 hours, then heated to 50 °C and stirred for 5 hours. The mixture was then cooled to room temperature, extracted with MC, and washed with distilled water. The extracted solution was dried over anhydrous MgSO4 and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain compound TA-01 (yield 37.45%). The [M]+ value of compound TA-01, as measured by high-resolution mass spectrometry, was 670.

[0174] 1-2. Synthesis of compound TA-03

[0175] The polycyclic compound TA-03 according to embodiments of the present disclosure can be synthesized, for example, by reaction 2 below:

[0176] Reaction 2

[0177]

[0178] Synthesis of intermediate B

[0179] Pd2(dba)3 (0.03 eq), (t-Bu)3P (0.06 eq), NaOt-Bu (1 eq), and toluene (0.1 M, based on 1 eq reagent) were added to a flask containing N1,N1,N3-triphenylphenyl-1,3-diamine (1 eq) and 9-bromo-7aH,16bH-benzo[e]benzo[5,6]cyclopentadieno[3,4][1,2]azaboron[1,2-a]cyclopentadieno[c][1,2]azaborane (1.2 eq), and the mixture was refluxed and stirred for 5 hours. The mixture was then cooled to room temperature, extracted with MC, and washed with distilled water. The extracted solution was dried over anhydrous MgSO4 and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain intermediate B (yield 81%). The [M]+ value of intermediate B, as measured by high-resolution mass spectrometry, was 638.

[0180] Synthesis of compound TA-03

[0181] 0.1 M tert-butylbenzene (based on 1 eq reagent) was added to a flask containing intermediate B (1 eq), and the mixture was cooled to -78 °C. After 1 hour, n-butyllithium (1.2 eq) was added, and the mixture was warmed to room temperature. Subsequently, BBr3 (1.2 eq) and DIPEA (2 eq) were added, and the resulting mixture was stirred at room temperature for 13 hours, then heated to 50 °C and stirred for an additional 5 hours. The mixture was then cooled to room temperature, extracted with MC, and washed with distilled water. The extracted solution was dried over anhydrous MgSO4 and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain compound TA-03 (yield 43.2%). The [M]+ value of compound TA-03, as measured by high-resolution mass spectrometry, was 646.

[0182] 1-3. Synthesis of compound TA-04

[0183] The polycyclic compound TA-04 according to embodiments of the present disclosure can be synthesized, for example, by reaction 3 below:

[0184] Reaction 3

[0185]

[0186] Synthesis of intermediate C

[0187] Pd₂(dba)₃ (0.03 eq), (t-Bu)₃P (0.06 eq), NaOt-Bu (1 eq), and toluene (0.1 M, based on 1 eq reagent) were added to a flask containing N₁,N₃-diphenylphenyl-1,3-diamine (1 eq) and 3,7-dibromodibenzo[c,e]dibenzo[3,4:5,6][1,2]azaboron[1,2-a][1,2]azaborane (1.2 eq), and the mixture was refluxed and stirred for 5 hours. The mixture was then cooled to room temperature, extracted with MC, and washed with distilled water. The extracted solution was dried over anhydrous MgSO₄ and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain intermediate C (57% yield). The [M]⁺ value of intermediate C, as measured by high-resolution mass spectrometry, was 584.

[0188] Synthesis of compound TA-04

[0189] 0.1 M tert-butylbenzene (based on 1 eq reagent) was added to a flask containing intermediate C (1 eq), and the mixture was cooled to -78 °C. After 1 hour, n-butyllithium (1.2 eq) was added, and the mixture was warmed to room temperature. Subsequently, BBr3 (1.2 eq) and DIPEA (2 eq) were added, and the resulting mixture was stirred at room temperature for 13 hours, then heated to 50 °C and stirred for an additional 5 hours. The mixture was then cooled to room temperature, extracted with MC, and washed with distilled water. The extracted solution was dried over anhydrous MgSO4 and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain compound TA-04 (yield 23.8%). The [M]+ value of compound TA-04, as measured by high-resolution mass spectrometry, was 592.

[0190] 1-4. Synthesis of compounds TA-08 and TA-07

[0191] The polycyclic compounds TA-08 and TA-07 according to embodiments of the present disclosure can be synthesized, for example, by reaction 4 below:

[0192] Reaction 4

[0193]

[0194] Synthesis of intermediate D

[0195] Pd₂(dba)₃ (0.03 eq), (t-Bu)₃P (0.06 eq), NaOt-Bu (1 eq), and toluene (0.1 M, based on 1 eq reagent) were added to a flask containing 1,3-dibromobenzene (1 eq) and 3-chloro-10-phenyl-5,10-dihydrodibenzo[b,e][1,4]azaborane (2.1 eq), and the mixture was refluxed and stirred for 5 hours. The mixture was then cooled to room temperature, extracted with MC, and washed with distilled water. The extracted solution was dried over anhydrous MgSO₄ and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain intermediate D (63% yield). The [M]⁺ value of intermediate D, as measured by high-resolution mass spectrometry, was 652.

[0196] Synthesis of compound TA-08

[0197] Pd₂(dba)₃ (0.03 eq), (t-Bu)₃P (0.06 eq), NaOt-Bu (1 eq), and toluene (0.1 M, based on 1 eq reagent) were added to a flask containing aniline (1 eq) and intermediate D (1.2 eq), and the mixture was refluxed and stirred for 5 hours. The mixture was then cooled to room temperature, extracted with MC, and washed with distilled water. The extracted solution was dried over anhydrous MgSO₄ and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain compound TA-08 (37% yield). The [M]⁺ value of compound TA-08, as measured by high-resolution mass spectrometry, was 672.

[0198] Synthesis of compound TA-07

[0199] 0.1 M tert-butylbenzene (based on 1 eq reagent) was added to a flask containing compound TA-08 (1 eq), and the mixture was cooled to -78 °C. After 1 hour, n-butyllithium (1.2 eq) was added, and the mixture was warmed to room temperature. Subsequently, BBr3 (1.2 eq) and DIPEA (2 eq) were added, and the resulting mixture was stirred at room temperature for 13 hours, then heated to 50 °C and stirred for an additional 5 hours. The mixture was then cooled to room temperature, extracted with MC, and washed with distilled water. The extracted solution was dried over anhydrous MgSO4 and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain compound TA-07 (yield 38.7%). The [M]+ value of compound TA-07, as measured by high-resolution mass spectrometry, was 680.

[0200] 1-5. Synthesis of compound TA-11

[0201] The polycyclic compound TA-11 according to embodiments of the present disclosure can be synthesized, for example, by reaction 5 below:

[0202] Reaction 5

[0203]

[0204] Synthesis of compound TA-11

[0205] Pd₂(dba)₃ (0.03 eq), (t-Bu)₃P (0.06 eq), NaOt-Bu (1 eq), and toluene (0.1 M, based on 1 eq reagent) were added to a flask containing 1,3-dibromobenzene (1 eq) and 3,3'-(phenylboranediyl)bis(10-phenyl-5,10-dihydrodibenzo[b,e][1,4]azaborane) (1.2 eq), and the mixture was refluxed and stirred for 5 hours. The mixture was then cooled to room temperature, extracted with MC, and washed with distilled water. The extracted solution was dried over anhydrous MgSO₄ and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain compound TA-11 (yield 37%). The [M]⁺ value of compound TA-11, as measured by high-resolution mass spectrometry, was 669.

[0206] 1-6. Synthesis of compound TA-26

[0207] The polycyclic compound TA-26 according to embodiments of the present disclosure can be synthesized, for example, by reaction 6 below:

[0208] Reaction 6

[0209]

[0210] Synthesis of compound TA-26

[0211] Pd₂(dba)₃ (0.03 eq), (t-Bu)₃P (0.06 eq), NaOt-Bu (1 eq), and toluene (0.1 M, based on 1 eq reagent) were added to a flask containing 1,3-dibromobenzene (1 eq) and 3,3'-oxobis(10-phenyl-5,10-dihydrodibenzo[b,e][1,4]azaborane) (1.2 eq), and the mixture was refluxed and stirred for 5 hours. The mixture was then cooled to room temperature, extracted with MC, and washed with distilled water. The extracted solution was dried over anhydrous MgSO₄ and distilled under reduced pressure, followed by separation of the residue by column chromatography to obtain compound TA-26 (37% yield). The [M]⁺ value of compound TA-26, as measured by high-resolution mass spectrometry, was 597.

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

[0213] 2-1 Examples of organic electroluminescent devices including polycyclic compounds

[0214] Organic electroluminescent devices in Examples 1 to 7 and Comparative Examples 1 to 4 were fabricated using compounds TA-01, TA-03, TA-04, TA-07, TA-08, TA-11, and TA-26 in the examples and compounds C1 to C4 in the comparative examples, respectively, as dopant materials in the emission layer.

[0215] Compounds in the example

[0216]

[0217] Compounds in the comparative examples

[0218]

[0219] Organic layer material

[0220]

[0221] ΔE ST Measurement of value

[0222] The singlet (S1) and triplet (T1) energy levels of the example compounds TA-01, TA-03, TA-04, TA-07, TA-08, TA-11, and TA-26 were calculated using non-empirical molecular orbital methods. Specifically, the S1 and T1 energy levels of the aforementioned compounds were calculated using the Gaussian09 software program, available from Gaussian Inc. These calculations were performed using a B3LYP hybrid functional and a 6-31G(d) basis set (B3LYP / 6-31G(d)).

[0223] Table 1 shows the S1 level, T1 level, and ΔE for compounds TA-01, TA-03, TA-04, TA-07, TA-08, TA-11, and TA-26 in the examples. ST value.

[0224] Table 1

[0225]

[0226] In Table 1, ΔE ST This represents the energy difference between the singlet and triplet levels. In Table 1, the units for the S1 and T1 levels are eV. All compounds in the examples have values ​​less than 0.3, which is interpreted as the ΔE value that allows thermally activated delayed fluorescence emission. ST The upper limit of the value indicates that the compound can be used as a thermally activated delayed fluorescence material.

[0227] Manufacturing of organic electroluminescent devices

[0228] In the organic electroluminescent devices of Examples 1 to 7 and Comparative Examples 1 to 4, ITO is used to form approximately The first electrode EL1 has a thickness of approximately [missing information]. It is formed from NPB. A hole injection layer (HIL) of a certain thickness is formed by mCP. A hole transport layer (HTL) of thickness was formed. In addition to mCBP, compounds with a thickness of 3% were doped into the example and comparative examples to form a layer with... The emitter layer EML is of a certain thickness. Compound ETL1 is used to form an emitter layer with... The electron transport layer (ETL) of a certain thickness is formed from Al. The second electrode EL2 is of thickness. Each layer is formed by vacuum deposition. The organic electroluminescent device of Comparative Example 1 is fabricated in substantially the same manner as the organic electroluminescent devices of Examples 1 to 7, except that BH1 / C1 is used as the host / dopant for the emitter layer EML.

[0229] Evaluation of the characteristics of organic electroluminescent devices

[0230] The characteristics of the fabricated organic electroluminescent devices were evaluated using a brightness orientation characteristic measurement device. To evaluate the characteristics of the organic electroluminescent devices according to example and comparative examples, the driving voltage, current efficiency, and external quantum efficiency were measured. Current efficiency is defined as 10 mA / cm². 2 The value of the current density.

[0231] Table 2

[0232]

[0233] Referring to the results in Table 2, it can be seen that when the polycyclic compound according to the embodiments of this disclosure is applied as a dopant material for the emitter layer to an organic electroluminescent device, low driving voltage and high efficiency are achieved. For example, it can be seen that low driving voltage and high efficiency are achieved in Examples 1 to 7 compared to Comparative Examples 1 to 4. In Examples 1 to 7, low driving voltage and high efficiency are achieved because the driving voltage is 4.4V to 5.2V, the current efficiency is 19.54cd / A to 27cd / A, and the external quantum efficiency is 14.4% to 18.4%. In Comparative Examples 1 to 4, low driving voltage and high efficiency are not achieved because the driving voltage is 5.4V to 7.44V, the current efficiency is 4.84cd / A to 18.7cd / A, and the external quantum efficiency is 2.99% to 13.7%.

[0234] The compounds in Examples 1 to 3 of this disclosure have boron-nitrogen (BN) direct bonds, such that the compounds can be considered to have electrochemical properties different from those in Comparative Example 3, which does not have BN direct bonds. Therefore, it can be considered that low drive voltage and high efficiency of the device are achieved by using the polycyclic compounds according to the embodiments of this disclosure.

[0235] In Examples 4 to 7 of this disclosure, the Y4 position of the polycyclic compounds represented by Formulas 1-2 is substituted with a heteroatom, resulting in increased planarity of the compounds in Examples 4 to 7 compared to the compounds in the comparative examples. Therefore, it can be considered that the resulting device achieves low driving voltage and high efficiency because the compounds have different stereochemical properties compared to the compounds in the comparative examples.

[0236] According to embodiments of this disclosure, organic electroluminescent devices with low driving voltage and high efficiency can be realized.

[0237] According to embodiments of this disclosure, polycyclic compounds can be applied to organic electroluminescent devices to help reduce driving voltage and improve efficiency.

[0238] As used herein, the term “and / or” includes any and all combinations of one or more of the related listed items. When a statement such as “at least one of…” follows a list of elements, it modifies the entire list of elements, not individual elements within that list.

[0239] As used herein, the terms “basically,” “approximately,” and similar terms are used as approximate terms rather than as terms of degree, and are intended to account for inherent deviations in measured or calculated values ​​that will be recognized by those skilled in the art. Furthermore, when describing embodiments of this disclosure, the use of “may” refers to “one or more embodiments of this disclosure.” As used herein, the terms “use” and variations thereof may be considered synonymous with the terms “utilize” and variations thereof, respectively. Additionally, the term “exemplary” is intended to indicate an example or illustration.

[0240] Furthermore, any numerical range stated herein is intended to include all subranges with 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 both 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 expressly state any subranges contained within the range expressly stated herein.

[0241] Although exemplary embodiments of this disclosure have been described, it is understood that this disclosure should not 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 the appended claims and their equivalents.

Claims

1. A polycyclic compound, said polycyclic compound being represented by formula A1 or formula A2: Formula A1 Formula A2 In equations A1 and A2, Both R2 and R3 are independently hydrogen atoms, deuterium atoms, or substituted or unsubstituted alkyl groups having one to six carbon atoms. Both m and n are independent integers from 0 to 4. X1 is B, X2 is NR 1-2 , a = 1 R 1-2 substituted or unsubstituted aryl having 6 to 15 ring-forming carbon atoms, Y1 is NR5. R5 is an aryl group with 6 to 15 cyclic carbon atoms, either substituted or unsubstituted, and The substituents in the substituted alkyl and substituted aryl groups are selected from the group consisting of a deuterium atom and an alkyl group having one to six carbon atoms.

2. The polycyclic compound according to claim 1, wherein, R5 is an unsubstituted phenyl group.

3. A polycyclic compound, wherein, The polycyclic compound is represented by any one of the compounds represented in compound group 1: Compound group 1 。 4. An organic electroluminescent device, the organic electroluminescent device comprising: First electrode; The second electrode is located on the first electrode; as well as Multiple organic layers are located between the first electrode and the second electrode. The first electrode and the second electrode each independently comprise at least one substance selected from the following: Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti; a composite selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti; a mixture selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti; and a transparent metal oxide. Wherein, at least one of the organic layers comprises a polycyclic compound according to any one of claims 1 to 3.

5. The organic electroluminescent device according to claim 4, wherein the organic layers respectively comprise: The hole transport region is located on the first electrode; The emission layer is located on the hole transport region; as well as The electron transmission region is located on the emission layer. The emitter layer comprises a host and a dopant, and The dopant includes the polycyclic compound.

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