Organic electroluminescent devices and polycyclic compounds for organic electroluminescent devices

Abstract

This application relates to a polycyclic compound represented by Formula 1 and an organic electroluminescent device, all of which include: a first electrode, a hole transport region on the first electrode, an emission layer on the hole transport region, an electron transport region on the emission layer, and a second electrode on the electron transport region, wherein the emission layer comprises the polycyclic compound represented by Formula 1.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2018-0158373, filed on December 10, 2018, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to organic electroluminescent devices and polycyclic compounds for use in organic electroluminescent devices. Background Technology

[0004] The development of organic electroluminescent display devices as image display devices is actively underway. Unlike liquid crystal displays, organic electroluminescent display devices are so-called self-emissive display devices, in which holes and electrons injected from a first electrode and a second electrode recombine in an emitting layer, and a light-emitting material containing organic compounds in the emitting layer is configured to emit light to display an image.

[0005] In applications of organic electroluminescent devices to display devices, it is beneficial to reduce the driving voltage of organic electroluminescent devices and increase emission efficiency and lifetime, and the development of materials for organic electroluminescent devices to stably meet the requirements is basically ongoing.

[0006] For example, recently, in order to provide highly efficient organic electroluminescent devices, techniques for phosphorescence emission (which uses triplet energy) or delayed fluorescence emission (which uses the phenomenon of singlet exciton generation through collisions of triplet excitons (triplet-triplet annihilation, "TTA")) are being developed, and materials for thermally activated delayed fluorescence (TADF) using the delayed fluorescence phenomenon are being developed. Summary of the Invention

[0007] This disclosure relates to organic electroluminescent devices and polycyclic compounds used in said organic electroluminescent devices.

[0008] For example, embodiments of this disclosure provide organic electroluminescent devices with long lifespans and high efficiency, as well as polycyclic compounds used therein.

[0009] Embodiments of this disclosure also provide organic electroluminescent devices comprising materials configured to emit thermally activated delayed fluorescence and polycyclic compounds used as materials configured to emit thermally activated delayed fluorescence.

[0010] Embodiments of this disclosure provide an organic electroluminescent device, the organic electroluminescent device comprising a first electrode, a hole transport region on the first electrode, an emission layer on the hole transport region, an electron transport region on the emission layer, and a second electrode on the electron transport region, wherein the emission layer comprises a polycyclic compound represented by the following formula 1:

[0011] Formula 1

[0012]

[0013] In Equation 1, Y is B, P, N, or P=O. In the case where Y is B or P=O, Z1 and Z2 are each independently N or P. In the case where Y is N or P, Z1 and Z2 are each independently B or P=O. Rings A to C are each independently a substituted or unsubstituted aryl ring having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl ring having 2 to 30 ring-forming carbon atoms. X1 and X2 are each independently a substituted or unsubstituted... An aryl group having 6 to 30 carbon atoms forming a ring, or a heteroaryl group having 2 to 30 carbon atoms forming a ring, substituted or unsubstituted, wherein at least one substituent bonded to at least one of rings A to C, X1 and X2 is -Si(Ra)3 or -Si(Ra)2-, and Ra is an aryl group having 6 to 30 carbon atoms forming a ring, substituted or unsubstituted, or a heteroaryl group having 2 to 30 carbon atoms forming a ring, substituted or unsubstituted.

[0014] In one implementation, the emitting layer can emit delayed fluorescence.

[0015] In an embodiment, the emission layer may be a delayed fluorescence emission layer comprising a host and a dopant, and the dopant may include the polycyclic compound.

[0016] In one implementation, the emitting layer may be a thermally activated delayed fluorescence emitting layer configured to emit blue light.

[0017] In Formula 1, the substituents of rings A to C, X1 and X2 can be deuterium atoms, halogen atoms, nitro groups, cyano groups, hydroxyl groups, substituted or unsubstituted amine groups, substituted or unsubstituted thiol groups, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 ring-forming carbon atoms, substituted or unsubstituted aryloxy groups having 6 to 30 ring-forming carbon atoms, substituted or unsubstituted heteroaryl groups having 2 to 30 ring-forming carbon atoms, substituted or unsubstituted arylsilyl groups, or substituted or unsubstituted heteroarylsilyl groups, or can be combined with adjacent groups to form a ring.

[0018] In the implementation scheme, Z1 and Z2 in Equation 1 can be the same.

[0019] In the implementation scheme, Y can be N, and Z1 and Z2 can each be B independently.

[0020] In the implementation scheme, equation 1 can be represented by the following equation 2:

[0021] Formula 2

[0022]

[0023] In Formula 2, R1 to R5 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, an substituted or unsubstituted aryloxy group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroalkyl group having 2 to 30 ring-forming carbon atoms. The aryl group, substituted or unsubstituted arylsilyl group, or substituted or unsubstituted heteroarylsilyl group, or combined with an adjacent group to form a ring, at least one of R1 to R5 is -Si(Ra)3, or at least one pair of R1 and R2, R2 and R5, R5 and R3, R3 and R4, and R1 and R4 is -Si(Ra)2-, "e" and "f" are each independently an integer from 0 to 4, "g" is an integer from 0 to 3, "h" and "i" are each independently an integer from 0 to 5, and Y, Z1, Z2 and Ra are the same as defined in Formula 1.

[0024] In the implementation scheme, equation 2 can be represented by any one of the following equations 2-1 to 2-3:

[0025] Equation 2-1

[0026]

[0027] Equation 2-2

[0028]

[0029] Equation 2-3

[0030]

[0031] In Equations 2-1 to 2-3, “p” is an integer from 0 to 3, “q” is an integer from 0 to 2, “r” is an integer from 0 to 4, and R1 to R5, Ra and “e” to “i” are the same as those defined in Equation 2.

[0032] In Equation 2, Y can be N.

[0033] In the implementation scheme, equation 1 can be represented by the following equation 3:

[0034] Formula 3

[0035]

[0036] In Equation 3, R6 to R 26 Each of the following groups is independently a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, a substituted or unsubstituted arylsilyl group, or a substituted or unsubstituted heteroarylsilyl group, or combined with an adjacent group to form a ring, R6 to R 26 At least one of them is -Si(Ra)3, or R6 and R 26 R9 and R 10 R 14 and R 15 R 17 and R 18 and R 22 and R 23 At least one pair in the equation is -Si(Ra)2-, and Y, Z1, Z2 and Ra are the same as those defined in Equation 1.

[0037] In embodiments of this disclosure, a polycyclic compound represented by Formula 1 is provided. Attached Figure Description

[0038] 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 the present disclosure and, together with the description, serve to explain the principles of the disclosure. In the drawings:

[0039] Figure 1 This is a schematic cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present disclosure;

[0040] Figure 2 This schematically illustrates a cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure; and

[0041] Figure 3 This is a schematic cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present disclosure. Detailed Implementation

[0042] 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 being limited to the embodiments set forth herein. Rather, all modifications, equivalents, and substitutions that are contained within the spirit and scope of this disclosure should be included in this disclosure.

[0043] The same reference numerals refer to the same elements throughout. In the accompanying drawings, the dimensions of the structures may be enlarged for clarity. It should be understood that although the terms first, second, etc., may be used herein to describe different elements, these elements should not be limited to these terms. These terms are used only to distinguish one element from another. Therefore, 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, the singular form is intended to also include the plural form unless the context clearly indicates otherwise.

[0044] It should also be understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of the described features, figures, behaviors, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, figures, behaviors, operations, elements, components, or combinations thereof. It should also be understood that when a layer, film, region, plate, etc., is referred to as being "on" another component, it may be "directly" on the other component, or there may be an intermediate layer present. Furthermore, it should be understood that when an element or layer is referred to as being "between" two elements or layers, it may be the only element or layer between the two elements or layers, or there may be one or more intermediate elements or layers present.

[0045] In the following text, reference will be made to Figures 1 to 3 Explain an organic electroluminescent device according to an embodiment of this disclosure.

[0046] refer to Figures 1 to 3 The organic electroluminescent device 10 according to the embodiment may include a first electrode EL1, a hole transport region HTR, an emitter layer EML, an electron transport region ETR, and a second electrode EL2 stacked in a prescribed order (e.g., laminated one by one).

[0047] The first electrode EL1 and the second electrode EL2 are positioned opposite each other, and a plurality of organic layers may be disposed between the first electrode EL1 and the second electrode EL2. The plurality of organic layers may include a hole transport region (HTR), an emitter layer (EML), and an electron transport region (ETR). The organic electroluminescent device 10 of the embodiment may contain a polycyclic compound of the embodiment within the emitter layer (EML).

[0048] At the same time, when with Figure 1 In comparison, 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. Furthermore, when combined with… Figure 1 In comparison, 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.

[0049] In the organic electroluminescent device 10 of the disclosed embodiment, the first electrode EL1 is conductive (e.g., is electrically conductive). The first electrode EL1 can be formed using a metal alloy or a conductive compound. The first electrode EL1 can be, for example, an anode.

[0050] The first electrode EL1 can be a transmissive electrode, a semi-transmissive reflective electrode, or a reflective electrode. If the first electrode EL1 is a transmissive electrode, it can be formed using a transparent metal oxide (such as, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO)). If the first electrode EL1 is a semi-transmissive reflective electrode or a reflective electrode, it can contain Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, their compounds, or mixtures thereof (e.g., a mixture of Ag and Mg). Furthermore, the first electrode EL1 can have a structure comprising multiple layers, including a reflective layer and / or a semi-transmissive reflective layer formed using the above materials, and a transmissive conductive layer formed using ITO, IZO, ZnO, and / or ITZO. For example, the first electrode EL1 can include multiple layers comprising ITO / Ag / ITO.

[0051] A hole transport region HTR is provided on the first electrode EL1. The hole transport region HTR may include at least one selected from the hole injection layer HIL, the hole transport layer HTL, the hole buffer layer, and the electron blocking layer EBL.

[0052] Hole transport region (HTR) can have a single layer formed using a single material, a single layer formed using multiple different materials, or a multilayer structure including multiple layers formed using the same or multiple different materials.

[0053] For example, the hole transport region HTR can have a single-layer structure of a hole injection layer HIL or a hole transport layer HTL, or it can have a single-layer structure formed using a hole injection material and a hole transport material. In some embodiments, the hole transport region HTR can have a single-layer structure formed using a variety of different materials, or a structure of 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 laminated from the first electrode EL1, without limitation.

[0054] Hole transport regions (HTRs) can be formed using various suitable methods, such as vacuum deposition, spin coating, tape casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing and / or laser-induced thermal imaging (LITI).

[0055] The hole injection layer HIL of the organic electroluminescent device 10 of the embodiment can contain any suitable hole injection material available in the art. For example, the hole transport layer HIL can contain triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetra(pentafluorophenyl)borate (PPBI), N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-phenyl-4,4'-diamine (DNTPD), phthalocyanine compounds such as copper phthalocyanine, 4,4',4'-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB), N,N'-bis(1-naphthyl)-N,N'-diphenyl-4,4'-diamine (α-NPD), 4,4' Examples of polyaniline-4”-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4”-tris(N,N-2-naphthylphenylamino)triphenylamine (2-TNATA), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarboxynitrile (HAT-CN), etc. However, embodiments of this disclosure are not limited thereto.

[0056] The hole transport layer HTL of the organic electroluminescent device 10 of the embodiment can contain any suitable hole transport material available in the art. For example, the hole transport layer HTL can contain 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), carbazole derivatives (e.g., N-phenylcarbazole and polyvinylcarbazole), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD), 4,4',4”-tris(N-carbazolyl)triphenylamine (TCTA), N,N'-bis(1-naphthyl)-N,N'-diphenylbenzidine (NPB), N,N'-bis(1-naphthyl)-N,N'-diphenyl-4,4'-diamine (α-NPD), etc. However, the embodiments of this disclosure are not limited thereto.

[0057] Simultaneously, the hole transport region (HTR) may further include an electron blocking layer (EBL), which is located between the hole transport layer (HTL) and the emitter layer (EML). The electron blocking layer (EBL) can prevent or reduce electron injection from the electron transport region (ETR) to the hole transport region (HTR).

[0058] The electron blocking layer (EBL) can contain any suitable material known in the art. The electron blocking layer (EBL) may comprise, for example, carbazole derivatives (e.g., N-phenylcarbazole and / or polyvinylcarbazole), fluorine-based derivatives, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD), triphenylamine-based derivatives (e.g., 4,4',4”-tris(N-carbazolyl)triphenylamine (TCTA)), N,N'-di(naphthyl-1-yl)-N,N'-diphenyl-benzidine (NPD), 4,4'-cyclohexylenebis[N,N-bis(4-methylphenyl)aniline] (TAPC), 4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl (HMTPD), 1,3-bis(carbazol-9-yl)benzene (mCP), etc. Furthermore, as described above, the electron blocking layer (EBL) may comprise polycyclic compounds according to embodiments of this disclosure.

[0059] 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 to approximately For example, the thickness of the electron blocking layer (EBL) can be approximately to approximately If 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, suitable or satisfactory hole transport properties can be achieved without a significant increase in driving voltage.

[0060] 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 uniformly or non-uniformly dispersed in the hole transport region (HTR). The charge-generating material may include, for example, a p-dopant. The p-dopant may be selected from quinone derivatives, metal oxides, and compounds containing cyano groups, without limitation. For example, non-limiting examples of p-dops may include quinone derivatives (e.g., tetracyanoquinone dimethyl ether (TCNQ) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinone dimethyl ether (F4-TCNQ)), metal oxides (e.g., tungsten oxide and molybdenum oxide), without limitation.

[0061] As described above, in addition to the hole injection layer (HIL) and the hole transport layer (HTL), the hole transport region (HTR) may further include at least one selected from the hole buffer layer and the electron blocking layer (EBL). The hole buffer layer can compensate for the resonant distance and increase the light emission efficiency according to the wavelength of the light emitted from the emitter layer (EML). The material included in the hole transport region (HTR) can be used as the material included in the hole buffer layer.

[0062] An emitter layer EML is provided on the hole transport region (HTR). The emitter layer EML can have, for example, approximately to approximately The thickness of the emitter layer (EML) is as follows. The EML can 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 the same or multiple different materials.

[0063] The emitting layer (EML) can emit light selected from red, green, blue, white, yellow, and cyan. The EML can contain fluorescent or phosphorescent emitting materials.

[0064] In some embodiments, the emitting layer EML may be a fluorescent emitting layer. For example, a portion of the light emitted from the emitting layer EML may be attributed to thermally activated delayed fluorescence (TADF). In some embodiments, the emitting layer EML may contain a luminescent component configured to emit thermally activated delayed fluorescence. In some embodiments, the emitting layer EML may be an emitting layer configured to emit blue light via thermally activated delayed fluorescence.

[0065] In the description, --* indicates the connection point (e.g., the location of a chemical bond).

[0066] In this description, the term "substituted or unsubstituted" means substituted or unsubstituted by at least one substituent selected from the group consisting of: deuterium, halogen, cyano, nitro, hydroxyl, amine, silyl, boron, phosphine oxide, phosphine sulfide, alkyl, alkenyl, alkoxy, aryl, aryloxy, and heteroaryl groups. Furthermore, each of the aforementioned substituents may be substituted or unsubstituted. For example, a biphenyl group can be understood as an aryl group or a phenyl group substituted with a phenyl group.

[0067] In this description, the term "forming a ring by bonding with an adjacent group" can mean forming a substituted or unsubstituted hydrocarbon ring, or a substituted or unsubstituted heterocycle, by bonding with an adjacent group. As used herein, the term "hydrocarbon ring" includes aliphatic hydrocarbon rings and aromatic hydrocarbon rings. As used herein, the term "heterocycle" includes aliphatic heterocycles and aromatic heterocycles. The ring formed by bonding with an adjacent group can be monocyclic or polycyclic. Furthermore, a ring formed by bonding with an adjacent group can bond with another ring to form a spirostructure.

[0068] In this description, the term "adjacent group" may mean a substituent that replaces an atom directly bonded to the atom substituted by the corresponding substituent, another substituent that replaces the atom substituted by the corresponding substituent, or a substituent spatially located at the position closest to the corresponding substituent. For example, in 1,2-dimethylbenzene, the two methyl groups may be understood as "adjacent groups" to each other, and in 1,1-diethylcyclopentane, the two ethyl groups may be understood as "adjacent groups" to each other.

[0069] In this description, the term "halogen atom" may refer to a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0070] In this description, the term "alkyl group" can refer to a straight-chain, branched, or cyclic alkyl group (or type of alkyl group). The number of carbon atoms in an alkyl group can be 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 The following are examples of compounds, without restriction: 2-hexyldecyl, 2-octyldecyl, undecyl, dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl, heptadecanyl, octadecyl, nonadecanyl, eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, hexadecyl, octadecyl, nonadecanyl, triadecyl, etc.

[0071] In this description, the term "aryl group" refers to a functional group or substituent derived from an aromatic hydrocarbon ring. Aryl groups can be monocyclic or polycyclic. The number of carbon atoms forming the ring 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[a]phenanthryl, pyrene, benzo[a]fluoranyl, and so on. Basic, etc., without restrictions.

[0072] In this description, the fluorenyl group may be substituted, and the two substituents of the fluorenyl group may combine with each other to form a spirostructure. Examples of substituted fluorenyl groups are given below. However, embodiments of this disclosure are not limited thereto.

[0073]

[0074] In this description, a heteroaryl group can be a heteroaryl group comprising at least one heteroatom selected from O, N, P, Si, and S. The number of carbon atoms in the forming ring of the heteroaryl group can be 2 to 30 or 2 to 20, and the number of heteroatoms in the forming ring of the heteroaryl group can be 1 to 10 or 1 to 5 (e.g., 1, 2, 3, 4, or 5). The heteroaryl group can be a monocyclic heteroaryl group or a polycyclic heteroaryl group. Examples of heteroaryl groups (e.g., polycyclic heteroaryl groups) can have a bicyclic or tricyclic structure. Examples of heteroaryl groups may include thiophene, furanyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridinel, pyridazinyl, quinolinyl, quinazolinyl, quinoxazinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazenopyrazinyl, isoquinolinyl, indoleyl, The following are unrestricted groups: carbazolyl, N-arylcarbazolyl, N-heteroarylcarbazolyl, N-alkylcarbazolyl, benzoxazolyl, benzoimidazolyl, benzothiazolyl, benzocarbazolyl, benzothiophene, dibenzothiophene, thiophene-thiophene, benzofuranyl, phenanthrolinel, isoxazolyl, thiadiazolyl, benzothiazolyl, phenothiazinyl, dibenzothiophene, dibenzofuranyl, etc.

[0075] In this description, silyl groups include alkylsilyl groups and arylsilyl groups. Examples of silyl groups may include trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, etc. However, embodiments of this disclosure are not limited thereto.

[0076] In the description, the number of carbon atoms in the amine group is not particularly limited, but can be from 1 to 30. The amine group can include alkylamine groups and / or arylamine groups. Examples of amine groups include, but are not limited to, methylamine groups, dimethylamine groups, phenylamine groups, naphthylamine groups, 9-methyl-anthraylamine groups, triphenylamine groups, etc.

[0077] In the implementation, the emitter layer EML contains a polycyclic compound represented by Formula 1.

[0078] Formula 1

[0079]

[0080] In Equation 1, Y is B, P, N or P = O. In the case where Y is B or P = O, Z1 and Z2 are each independently N or P, and in the case where Y is N or P, Z1 and Z2 are each independently B or P = O.

[0081] In Formula 1, rings A through C are each independently an aryl ring with 6 to 30 carbon atoms forming a ring, either substituted or unsubstituted, or a heteroaryl ring with 2 to 30 carbon atoms forming a ring, either substituted or unsubstituted.

[0082] In Formula 1, X1 and X2 are each independently an aryl group having 6 to 30 carbon atoms forming a ring, either substituted or unsubstituted, or a heteroaryl group having 2 to 30 carbon atoms forming a ring.

[0083] In Formula 1, at least one substituent bonded to at least one of rings A to C, X1, and X2 is -Si(Ra)3 or -Si(Ra)2-, and Ra is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms forming a ring. If at least one substituent bonded to at least one of rings A to C, X1, and X2 is -Si(Ra)2-, the substituent may combine with an adjacent group to form a ring.

[0084] The polycyclic compound represented by Formula 1 contains a bulky arylsilyl group or a heteroarylsilyl group as a substituent (e.g., a spatially large substituent). Although this application is not limited to any particular mechanism or theory, the presence of the arylsilyl group or the heteroarylsilyl group is thought to produce the following characteristics. Due to the presence of the spatially large substituent, the aggregation (or agglomeration) of the dopant can be suppressed or reduced. Furthermore, due to the presence of the arylsilyl group or the heteroarylsilyl group, the effects of exciton deactivation and the increase in the wavelength of emitted light due to intermolecular interactions can be prevented or reduced. In addition, due to the weak electron-withdrawing properties of the arylsilyl group or the heteroarylsilyl group, which each has a bulky size, the electronic state of the dopant can be altered, thereby reducing the wavelength of light emitted by the device containing the polycyclic compound. Furthermore, the roll-off, which is a phenomenon of reduced emission efficiency at high brightness, can be limited or reduced, and the half-width of light emitted from the device containing the polycyclic compound can be reduced to about 25 nm to about 35 nm, thereby contributing to an increase in device efficiency.

[0085] In the embodiments, in Formula 1, the substituents of rings A to C, X1 and X2 may be deuterium atoms, halogen atoms, nitro groups, cyano groups, hydroxyl groups, substituted or unsubstituted amine groups, substituted or unsubstituted thiol groups, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 ring-forming carbon atoms, substituted or unsubstituted aryloxy groups having 6 to 30 ring-forming carbon atoms, substituted or unsubstituted heteroaryl groups having 2 to 30 ring-forming carbon atoms, substituted or unsubstituted arylsilyl groups, or substituted or unsubstituted heteroarylsilyl groups, or may be combined with adjacent groups to form a ring.

[0086] In the implementation scheme, Z1 and Z2 in Equation 1 can be the same.

[0087] In the implementation scheme, in Equation 1, Y can be N, and Z1 and Z2 can each be B independently.

[0088] In the implementation scheme, equation 1 can be represented by the following equation 2:

[0089] Formula 2

[0090]

[0091] In Formula 2, R1 to R5 can each independently be a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, an substituted or unsubstituted aryloxy group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, a substituted or unsubstituted arylsilyl group, or a substituted or unsubstituted heteroarylsilyl group, or can be combined with adjacent groups to form a ring.

[0092] In Equation 2, at least one of R1 to R5 can be -Si(Ra)3, or at least one pair of R1 and R2, R2 and R5, R5 and R3, R3 and R4, and R1 and R4 can be -Si(Ra)2-. In the case where at least one pair of R1 to R5 is -Si(Ra)2-, a ring can be formed.

[0093] In Equation 2, "e" and "f" can each be an integer from 0 to 4 independently. At the same time, if "e" is 2 or greater than 2, the multiple R1 groups can be the same or different, and if "f" is 2 or greater than 2, the multiple R2 groups can be the same or different.

[0094] In Equation 2, "g" is an integer from 0 to 3. Also, if "g" is 2 or greater, the multiple R3 groups can be the same or different.

[0095] In Equation 2, "h" and "i" are each an independent integer from 0 to 5. Furthermore, if "h" is 2 or greater than 2, the multiple R4 groups can be the same or different, and if "i" is 2 or greater than 2, the multiple R5 groups can be the same or different.

[0096] In Equation 2, Y, Z1, Z2, and Ra are the same as those defined in Equation 1.

[0097] In the implementation scheme, equation 2 can be represented by any one of the following equations 2-1 to 2-3:

[0098] Equation 2-1

[0099]

[0100] Equation 2-2

[0101]

[0102] Equation 2-3

[0103]

[0104] In Equation 2-1, "p" is an integer from 0 to 3. Also, if "p" is 2 or greater than 2, then the multiple R2 groups are either identical or different.

[0105] In Equation 2-2, "q" is an integer from 0 to 2. Also, if "q" is 2 or greater than 2, then the multiple R3 groups are either identical or different.

[0106] In Equation 2-3, "r" is an integer from 0 to 4. Also, if "r" is 2 or greater, the multiple R4 groups are either identical or different.

[0107] In Equations 2-1 to 2-3, R1 to R5, Ra, and “e” to “i” are the same as those defined in Equation 2.

[0108] In the implementation scheme, Y in Equation 2 can be N.

[0109] In the implementation scheme, Z1 and Z2 in Equation 2 can be the same.

[0110] In the implementation scheme, Z1 and Z2 in Equation 2 can each be B independently.

[0111] In the implementation scheme, equation 1 can be represented by the following equation 3:

[0112] Formula 3

[0113]

[0114] In Equation 3, R6 to R 26 Each group may be independently a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, a substituted or unsubstituted arylsilyl group, or a substituted or unsubstituted heteroarylsilyl group, or may be combined with adjacent groups to form a ring.

[0115] In Equation 3, R6 to R 26 At least one of them can be -Si(Ra)3, or R6 and R 26 R9 and R 10 R 14 and R 15 R 17 and R18 and R 22 and R 23 At least one pair can be -Si(Ra)2-. Meanwhile, R6 and R... 26 R9 and R 10 R 14 and R 15 R 17 and R 18 and R 22 and R 23 In the case where at least one pair can be -Si(Ra)2-, a ring can be formed.

[0116] In Equation 3, Y, Z1, Z2, and Ra can be the same as those defined in Equation 1.

[0117] In the implementation scheme, Y in Equation 3 can be N.

[0118] In the implementation scheme, Z1 and Z2 in Equation 3 can be the same.

[0119] In the implementation scheme, Z1 and Z2 in Equation 3 can each be B independently.

[0120] In the implementation plan, R6 and R7, R7 and R8, R8 and R9, R 10 and R 11 R 11 and R 12 R 12 and R 13 R 13 and R 14 R 15 and R 16 R 16 and R 17 R 18 and R 19 R 19 and R 20 R 20 and R 21 R 21 and R 22 R 23 and R 24 R 24 and R 25 and R 25 and R 26 At least one pair can form a fused structure with any one of the following equations 3-1 to 3-4:

[0121]

[0122] In equations 3-1 to 3-4, R 27 To R 30and R b To R d Each of these can be independently a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.

[0123] In Equation 3-1, "j" is an integer from 0 to 4. Also, if "j" is 2 or greater than 2, then multiple R... 27 The functional groups may be the same or different.

[0124] In Equation 3-2, "k" is an integer from 0 to 4. Also, if "k" is 2 or greater than 2, then multiple R... 28 The functional groups may be the same or different.

[0125] In Equation 3-3, "l" is an integer from 0 to 4. Also, if "l" is 2 or greater than 2, then multiple R... 29 The functional groups may be the same or different.

[0126] In equation 3-4, "m" is an integer from 0 to 4. Also, if "m" is 2 or greater than 2, then multiple R... 30 The functional groups may be the same or different.

[0127] In the implementation plan, R6 to R9, R in Equation 3 10 To R 14 and R 15 To R 17 At least one of them can be -Si(Ra)3.

[0128] The polycyclic compound of the embodiment represented by Formula 1 can be a material configured to emit delayed fluorescence. The polycyclic compound of the embodiment can be a material configured to provide thermally activated delayed fluorescence. For example, the polycyclic compound of Formula 1 can be used as a blue emitting material configured to emit thermally activated delayed fluorescence. However, the embodiments of this disclosure are not limited thereto. The polycyclic compound of the embodiment can be used as a material for thermally activated delayed fluorescence, which can emit green or red light.

[0129] The compound represented by Formula 1 can be any one of the compounds represented in Group 1 of the following compounds:

[0130] Compound group 1

[0131]

[0132]

[0133]

[0134] The polycyclic compound represented by Formula 1 is used in the organic electroluminescent device 10 of the embodiment and can improve the efficiency and lifetime of the organic electroluminescent device. For example, the polycyclic compound represented by Formula 1 can be used in the emission layer EML of the organic electroluminescent device 10 of the embodiment and can improve the emission efficiency and lifetime of the organic electroluminescent device.

[0135] In this embodiment, the emitter layer (EML) comprises a host and a dopant, wherein the host may be configured to emit delayed fluorescence, and the dopant may be configured to emit delayed fluorescence. Additionally, a polycyclic compound of the embodiment represented by Formula 1 may be included as a dopant material of the emitter layer (EML). For example, the polycyclic compound of the embodiment represented by Formula 1 may be used as a TADF dopant.

[0136] Furthermore, in the embodiments, the emitter layer EML may comprise known host materials. For example, in the embodiments, the emitter layer EML may comprise, as host materials, tris(8-hydroxyquinoline)aluminum (Alq3), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (mCBP), poly(N-vinylcarbazole) (PVK), 9,10-bis(naphthyl-2-yl)anthracene (ADN), 4,4',4”-tris(carbazolyl-9-yl)-triphenylamine (TCTA), 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBi), 3-tert-butyl-9,10-bis(naphthyl-2-yl)anthracene (TBADN), or stilbeneylarylene (DSA). Examples of suitable host materials include 4,4'-bis(9-carbazolyl)-2,2'-dimethylbiphenyl (CDBP), 2-methyl-9,10-bis(naphthyl-2-yl)anthracene (MADN), bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetrasiloxane (DPSiO4), and 2,8-bis(diphenylphospho)dibenzofuran (PPF). However, embodiments of this disclosure are not limited thereto. In addition to the host materials described, any suitable host material available in the art configured to emit delayed fluorescence may be included.

[0137] In the organic electroluminescent device 10 of the embodiment, the emission layer EML may further comprise any suitable dopant material available in the art. In the embodiment, the emission layer EML may comprise styrene derivatives as dopant (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-tetratert-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1-dipyrene, 1,4-dipyrenebenzene, 1,4-bis(N,N-diphenylamino)pyrene), etc.

[0138] Refer again Figures 1 to 3 In the organic electroluminescent device 10 of the embodiment, an electron transport region (ETR) is provided on the emitter layer (EML). The electron transport region (ETR) may include at least one selected from a hole blocking layer, an electron transport layer (ETL), and an electron injection layer (EIL). However, embodiments of the present disclosure are not limited thereto.

[0139] The electronic transport region (ETR) can have 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 the same or multiple different materials.

[0140] For example, the electron transport region (ETR) can have a single-layer structure of an electron injection layer (EIL) or an electron transport layer (ETL), or a single-layer structure formed using an electron injection material and an electron transport material. Furthermore, the ETR can have a single-layer structure containing multiple different materials, or a structure of an electron transport layer / electron injection layer (EIL) or a hole blocking layer / electron transport layer / EIL laminated from the first electrode (EL1), without limitation. The thickness of the ETR can be, for example, approximately... to approximately

[0141] Various suitable methods (such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing and / or laser-induced thermal imaging (LITI)) can be used to form the electron transport region (ETR).

[0142] If the electron transport region (ETR) includes the electron transport layer (ETL), then the ETR can contain, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 1,3,5-tris[(3-pyridyl)-benzyl-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, 1,3,5-tris(1-phenyl-1H-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-(naphth-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-quinoline-N1,O8)-(1,1'-biphenyl-4-oxoline)aluminum (BAlq), bis(benzoquinoline-10-oxoline)beryllium (Bebq2), 9,10-bis(naphth-2-yl)anthracene (ADN), or mixtures thereof, without limitation.

[0143] If the electron transport region ETR includes the electron transport layer ETL, then the thickness of the electron transport layer ETL can be approximately to approximately And it can be, for example, about to approximately If the thickness of the electron transport layer (ETL) meets the above range, suitable or satisfactory electron transport properties can be obtained without a significant increase in driving voltage.

[0144] If the electron transport region (ETR) includes an electron injection layer (EIL), the ETR may contain, for example, LiF, lithium quinoline (LiQ), Li₂O, BaO, NaCl, CsF, lanthanides (e.g., Yb), and / or metal halides (e.g., RbCl, RbI, and / or KI). However, embodiments of this disclosure are not limited thereto. A mixture of electron injection material and insulating organometallic salt (e.g., organometallic salt) can also be used to form the electron injection layer (EIL). The organometallic salt may be a material having a band gap of about 4 eV or greater. In some embodiments, the organometallic salt may include, for example, metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates, and / or metal stearates.

[0145] If the electron transport region (ETR) includes the electron injection layer (EIL), then the thickness of the electron injection layer (EIL) can be approximately... to approximately For example, for about to approximately If the thickness of the electron injection layer (EIL) meets the above range, suitable or satisfactory electron injection properties can be obtained without causing a significant increase in the driving voltage.

[0146] The electron transport region (ETR) may include a hole blocking layer as described above. The hole blocking layer may contain at least one selected from, for example, 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.

[0147] A second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 is conductive (e.g., is electrically conductive). The second electrode EL2 can be formed using a metal alloy or a conductive compound. The second electrode EL2 can be a cathode. The second electrode EL2 can be a transmission electrode, a semi-transmissive reflective electrode, or a reflective electrode. If the second electrode EL2 is a transmission electrode, then the second electrode EL2 can contain a transparent metal oxide, such as ITO, IZO, ZnO, ITZO, etc.

[0148] If the second electrode EL2 is a semi-transparent or reflective electrode, then the second electrode EL2 may contain Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or compounds thereof or mixtures thereof (e.g., a mixture of Ag and Mg). The second electrode EL2 may have a multilayer structure, which includes a reflective or semi-transparent reflective layer formed using the above-described materials and a transparent conductive layer formed using ITO, IZO, ZnO, ITZO, etc.

[0149] In some implementations, the second electrode EL2 can be connected to an auxiliary electrode. If the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 can be reduced.

[0150] In the organic electroluminescent device 10, depending on the voltage applied to each of 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 recombine in the emitter layer EML to generate excitons, and the excitons can emit light via transitions from the excited state to the ground state.

[0151] If the organic electroluminescent device 10 is a top-emitting type, then the first electrode EL1 can be a reflective electrode, and the second electrode EL2 can be a transmissive electrode or a semi-transmissive reflective electrode. If the organic electroluminescent device 10 is a bottom-emitting type, then the first electrode EL1 can be a transmissive electrode or a semi-transmissive reflective electrode, and the second electrode EL2 can be a reflective electrode.

[0152] The organic electroluminescent device 10 of the embodiments of this disclosure uses the polycyclic compound as a material for the emission layer and can have improved emission efficiency and lifetime characteristics.

[0153] Embodiments of this disclosure provide polycyclic compounds represented by the following formula 1:

[0154] Formula 1

[0155]

[0156] In Equation 1, Y is B, P, N or P = O. In the case where Y is B or P = O, Z1 and Z2 are each independently N or P, and in the case where Y is N or P, Z1 and Z2 are each independently B or P = O.

[0157] In Formula 1, rings A through C are each independently an aryl ring with 6 to 30 carbon atoms forming a ring, either substituted or unsubstituted, or a heteroaryl ring with 2 to 30 carbon atoms forming a ring, either substituted or unsubstituted.

[0158] In Formula 1, X1 and X2 are each independently an aryl group having 6 to 30 carbon atoms forming a ring, either substituted or unsubstituted, or a heteroaryl group having 2 to 30 carbon atoms forming a ring.

[0159] In Formula 1, at least one substituent bonded to rings A to C, X1, and X2 is -Si(Ra)3 or -Si(Ra)2-, and Ra is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms forming a ring, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms forming a ring. If at least one substituent bonded to at least one selected from rings A to C, X1, and X2 is -Si(Ra)2-, the substituent may bond to an adjacent group to form a ring.

[0160] In the embodiments, in Formula 1, the substituents of rings A to C, X1 and X2 may be deuterium atoms, halogen atoms, nitro groups, cyano groups, hydroxyl groups, substituted or unsubstituted amine groups, substituted or unsubstituted thiol groups, substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, substituted or unsubstituted alkoxy groups having 1 to 20 carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 ring-forming carbon atoms, substituted or unsubstituted aryloxy groups having 6 to 30 ring-forming carbon atoms, substituted or unsubstituted heteroaryl groups having 2 to 30 ring-forming carbon atoms, substituted or unsubstituted arylsilyl groups, or substituted or unsubstituted heteroarylsilyl groups, or may be combined with adjacent groups to form a ring.

[0161] In the implementation scheme, Z1 and Z2 in Equation 1 can be the same.

[0162] In the implementation scheme, in Equation 1, Y can be N, and Z1 and Z2 can each be B independently.

[0163] In the implementation scheme, equation 1 can be represented by the following equation 2:

[0164] Formula 2

[0165]

[0166] In Formula 2, R1 to R5 can each independently be a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted amine group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, an substituted or unsubstituted aryloxy group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, a substituted or unsubstituted arylsilyl group, or a substituted or unsubstituted heteroarylsilyl group, or can be combined with adjacent groups to form a ring.

[0167] In Equation 2, at least one of R1 to R5 can be -Si(Ra)3, or at least one pair of R1 and R2, R2 and R5, R5 and R3, R3 and R4, and R1 and R4 can be -Si(Ra)2-. In the case where at least one pair of R1 and R2, R2 and R5, R5 and R3, R3 and R4, and R1 and R4 is -Si(Ra)2-, a ring can be formed.

[0168] In Equation 2, "e" and "f" can each be an integer from 0 to 4 independently. Furthermore, if "e" is 2 or greater than 2, then the multiple R1 groups are the same or different, and if "f" is 2 or greater than 2, then the multiple R2 groups are the same or different.

[0169] In Equation 2, "g" is an integer from 0 to 3. Also, if "g" is 2 or greater than 2, then the multiple R3 groups are either identical or different.

[0170] In Equation 2, "h" and "i" are each an independent integer from 0 to 5. Furthermore, if "h" is 2 or greater than 2, then the multiple R4 groups are identical or different, and if "i" is 2 or greater than 2, then the multiple R5 groups are identical or different.

[0171] In Equation 2, Y, Z1, Z2, and Ra are the same as those defined in Equation 1.

[0172] Furthermore, the same interpretation of the polycyclic compounds in the organic electroluminescent devices of the embodiments can be applied to the polycyclic compounds of the embodiments represented by Formulas 1 and 2.

[0173] The polycyclic compound according to the implementation scheme may be any one of the compounds represented in compound group 1 above.

[0174] The subject matter of this disclosure will be explained below with reference to embodiments and comparative examples. The following embodiments are merely illustrative to aid in understanding this disclosure, and the scope of this disclosure is not limited thereto.

[0175] Example

[0176] 1. Synthesis of polycyclic compounds

[0177] First, the synthesis methods of polycyclic compounds according to exemplary embodiments of this disclosure will be explained with reference to the synthesis methods of compounds 6, 9, 11, and 13. Furthermore, the synthesis methods of polycyclic compounds explained below are merely embodiments, and the synthesis methods of polycyclic compounds according to embodiments of this disclosure are not limited thereto.

[0178] Synthesis of Compound 6

[0179] The polycyclic compound (compound 6) according to the embodiment can be synthesized as follows.

[0180] Reaction 1

[0181]

[0182] Xylylamine (5.00 g, 25 mmol), (4-bromophenyl)triphenylsilane (12.63 g, 30 mmol), Pd(dba)₂ (0.46 g, 0.50 mmol), BF₄PH(tBu)₃ (0.59 g, 2.0 mmol), NaOtBu (3.05 g, 32 mmol), and 130 mL of toluene were stirred at approximately 80 °C for about 4 hours under an Ar atmosphere, and then filtered through a silica gel pad using toluene as solvent. The resulting reaction solution was concentrated and subjected to silica gel column chromatography (eluent: hexane and toluene). Recrystallization was then performed using a mixture of hexane and toluene as solvent, yielding 11.45 g of a white solid in 83% yield. The molecular weight of the obtained compound was determined by fast atom bombardment mass spectrometry (FAB-MS) and found to be 532, and the compound was identified as target compound A.

[0183] Reaction 2

[0184]

[0185] Compound A (1.20 g, 2.3 mmol), triphenylborane (4.37 g, 18 mmol), and 25 mL of o-dichlorobenzene (ODCB) were stirred under an Ar atmosphere. Boron triiodide (7.10 g, 18 mmol) was added, and the mixture was heated and stirred at approximately 180 °C for about 8 hours. The resulting product was then cooled to room temperature, and a THF solution of 1.0 M, 24 mL, 28.8 mmol of Grignard reagent was added. After stirring at room temperature for 1 hour, the mixture was heated and stirred at approximately 60 °C for about 3 hours. The reaction solution was extracted with toluene and dried over MgSO4, and subjected to silica gel column chromatography (eluent: hexane and toluene). Recrystallization was then performed using a mixture of hexane and toluene to give 0.94 g of a yellow solid in 53% yield. The molecular weight of the obtained compound was determined by FAB-MS and found to be 787, and the compound was identified as target compound 6.

[0186] Synthesis of Compound 9

[0187] The polycyclic compound (compound 9) according to the embodiment can be synthesized as follows.

[0188] Reaction 3

[0189]

[0190] Compound B-1 (4.00 g, 7.0 mmol), (3-bromophenyl)phenylthione (2.23 g, 8.4 mmol), Pd(dba)2 (0.13 g, 0.14 mmol), BF4PH(tBu)3 (0.16 g, 0.56 mmol), NaOtBu (0.84 g, 32 mmol), and 35 mL of toluene were stirred at approximately 80 °C for about 4 hours under an Ar atmosphere, and then filtered through a silica gel pad using toluene as solvent. The resulting reaction solution was concentrated and subjected to silica gel column chromatography (eluent: hexane and toluene). Recrystallization was then performed using a mixture of hexane and toluene as solvent, yielding 4.08 g of a white solid in 77% yield. The molecular weight of the obtained compound was determined by FAB-MS and found to be 754, and the compound was identified as the target compound B-2.

[0191] Reaction 4

[0192]

[0193] Compound B-2 (3.0 g, 4.0 mmol) and 23 mL of xylene were stirred under an Ar atmosphere and then cooled to approximately 0 °C. BuLi (1.6 M, 2.8 mL, 4.4 mmol) was slowly added, followed by stirring at room temperature for approximately 30 minutes, heating and stirring at approximately 100 °C for approximately 3 hours, and then cooling to approximately -20 °C. BBr3 heptane solution (1.0 M, 5.2 mL, 5.2 mmol) was slowly added, followed by stirring at room temperature for approximately 1 hour, and then cooling to approximately 0 °C. Diisopropylethylamine (EtN(iPr)2, 1.4 mL, 8.0 mmol) was added, followed by stirring at approximately 120 °C for approximately 12 hours, and then cooling to room temperature. The organic layer was then extracted from the reaction solution with toluene, dried over MgSO4, and concentrated under reduced pressure. Silica gel column chromatography was performed (eluent: hexane and toluene). Then, recrystallization was performed using a mixture of hexane and toluene as a solvent to obtain 1.4 g of a yellow solid in 60% yield. The molecular weight of the obtained compound was measured by FAB-MS and found to be 762, and the compound was identified as target compound 9.

[0194] Synthesis of Compound 11

[0195] The polycyclic compound (compound 11) according to the embodiment can be synthesized as follows.

[0196] Reaction 5

[0197]

[0198] Compound C-1 (5.5 g, 8.5 mmol), benzenethiol (2.3 g, 21 mmol), Cs₂CO₃ (6.9 g, 21 mmol), and 28 mL of NMP were stirred at approximately 180 °C for about 20 hours under an Ar atmosphere, and then filtered through a silica gel pad using toluene as solvent. The resulting reaction solution was concentrated and subjected to silica gel column chromatography (eluent: hexane and toluene). Recrystallization was then performed using a mixture of hexane and toluene as solvent, yielding 4.6 g of a white solid in 74% yield. The molecular weight of the obtained compound was determined by FAB-MS and found to be 740, and the compound was identified as the target compound C-2.

[0199] Reaction 6

[0200]

[0201] Compound C-2 (3.0 g, 4.1 mmol) and 23 mL of xylene were stirred under an Ar atmosphere and then cooled to approximately 0 °C. BuLi (1.6 M, 2.8 mL, 4.4 mmol) was slowly added, followed by stirring at room temperature for approximately 30 minutes, heating and stirring at approximately 100 °C for approximately 5 hours, and then cooling to approximately -20 °C. BBr3 heptane solution (1.0 M, 5.3 mL, 5.3 mmol) was slowly added, followed by stirring at room temperature for approximately 1 hour, and then cooling to approximately 0 °C. Diisopropylethylamine (EtN(iPr)2, 1.4 mL, 8.1 mmol) was added, followed by stirring at approximately 120 °C for approximately 20 hours, and then cooling to room temperature. The organic layer was then extracted from the reaction solution with toluene, dried over MgSO4, and concentrated under reduced pressure. Silica gel column chromatography was performed (eluent: hexane and toluene). Then, recrystallization was performed using a mixture of hexane and toluene as a solvent to obtain 0.94 g of a yellow solid in 42% yield. The molecular weight of the obtained compound was measured by FAB-MS and found to be 745, and the compound was identified as target compound 11.

[0202] Synthesis of Compound 13

[0203] The polycyclic compound (compound 13) according to the embodiment can be synthesized as follows.

[0204] Reaction 7

[0205]

[0206] Compound D-1 (4.0 g, 11 mmol), compound D-2 (4.3 g, 12 mmol), Pd(dba)2 (0.19 g, 0.21 mmol), BF4PH(tBu)3 (0.25 g, 0.84 mmol), NaOtBu (1.3 g, 13 mmol), and 60 mL of toluene were stirred at approximately 80 °C for about 4 hours under an Ar atmosphere, and then filtered through a silica gel pad using toluene as solvent. The resulting reaction solution was concentrated and subjected to silica gel column chromatography (eluent: hexane and toluene). Recrystallization was then performed using a mixture of hexane and toluene as solvent, yielding 5.6 g of a white solid in 80% yield. The molecular weight of the obtained compound was determined by FAB-MS and found to be 666, and the compound was identified as the target compound D-3.

[0207] Reaction 8

[0208]

[0209] Compound D-3 (2.00 g, 3.0 mmol), triphenylborane (1.45 g, 6.0 mmol), and 30 mL of o-dichlorobenzene (ODCB) were stirred under an Ar atmosphere, and boron triiodide (5.90 g, 15 mmol) was added. The mixture was then heated and stirred at approximately 180 °C for about 24 hours. The reaction solution was then cooled to room temperature and phosphate buffer was added. The resulting product was extracted with toluene, dried over MgSO4, and filtered through a silica gel pad using toluene as solvent. The product was then washed with a mixture of hexane and toluene using sonication. Recrystallization with toluene yielded 1.57 g of a yellow solid in 77% yield. The molecular weight of the obtained compound was determined by FAB-MS and found to be 681, and the compound was identified as target compound 13.

[0210] 2. Fabrication and evaluation of organic electroluminescent devices containing polycyclic compounds

[0211] Manufacturing of organic electroluminescent devices

[0212] Organic electroluminescent devices of exemplary embodiments, in which an exemplary embodiment of a polycyclic compound is incorporated in the emitter layer, are manufactured using the methods described below. Organic electroluminescent devices of Examples 1 to 4 are manufactured using polycyclic compounds 6, 9, 11, and 13 as materials for the emitter layer. The compounds used in the emitter layers of Examples 1 to 4 and Comparative Examples 1 to 4 are as follows.

[0213] Table 1

[0214]

[0215] The organic electroluminescent devices of the embodiments and comparative examples are manufactured using the methods described below.

[0216] On the glass substrate, there will be approximately The ITO pattern was fabricated to a thickness of [thickness value] and washed with ultrapure water, followed by UV ozone treatment for approximately 10 minutes. Then, HAT-CN was deposited to a thickness of [thickness value]. The thickness of α-NPD is deposited to approximately [amount missing]. The thickness, and the mCP is deposited to approximately The thickness is increased to form a hole transport region.

[0217] Then, the various compounds from the polycyclic compound of the embodiment and the comparative compound are co-deposited with mCBP at a ratio of 5:95 to form a layer of approximately [missing information]. The thickness. That is, in order to form an emission layer by co-deposition, each of the compounds 6, 9, 11 and 13 was mixed with mCBP and deposited in Examples 1 to 4, and each of the comparative compounds X-1, X-2, X-3 and X-4 was mixed with mCBP and deposited in Comparative Examples 1 to 4.

[0218] On the emitter layer, a TPBi layer is formed to approximately [size missing]. The thickness, and using LiF to form a layer to approximately The thickness is adjusted to form an electron transport region. Then, a second electrode is formed using aluminum (Al) to approximately [amount missing]. The thickness.

[0219] In this embodiment, a hole transport region, an emitter layer, an electron transport region, and a second electrode are formed using a vacuum deposition apparatus.

[0220] Evaluation of the properties of organic electroluminescent devices

[0221] To evaluate the properties of the organic electroluminescent devices of the embodiments and comparative examples, the maximum emission wavelength (nm), maximum external quantum yield (%), and other parameters at 1,000 cd / m² were evaluated. 2 External quantum yield (%) and half-width were measured using a luminance measurement device C9920-11 from Hamamatsu Photonics Co.

[0222] Table 2

[0223]

[0224] Referring to Table 2, compared with the organic light-emitting devices of Comparative Examples 1 to 4, the organic electroluminescent devices of Examples 1 to 4, which used the polycyclic compound of the embodiment as the dopant material for the emission layer, exhibited higher external quantum efficiency and smaller half-width. Furthermore, it was found that the organic electroluminescent devices of Examples 1 to 4, which used the polycyclic compound of the embodiment as the dopant material for the emission layer, exhibited an emission wavelength of approximately 470 nm or less and deep blue emission.

[0225] Referring to the results in Table 2, the exemplary compounds were found to exhibit high emission efficiency in the deep blue emission region and can be used as materials with high efficiency for thermally activated delayed fluorescence.

[0226] The organic electroluminescent device of the embodiment includes a polycyclic compound in the emission layer of the embodiment, and can achieve deep blue light with a relatively short wavelength, while at the same time, a reduced emission half-width and high emission efficiency can be obtained.

[0227] Compared to Comparative Examples 1 to 4, the polycyclic compounds of the embodiments contain arylsilyl groups or heteroarylsilyl groups as substituents with large volume. Because the silyl substituents have large volume, they can suppress or reduce the aggregation of dopants under high concentration conditions, thereby preventing or reducing the effects of exciton deactivation (or dissociation) due to intermolecular interactions and increasing the wavelength of emitted light. Furthermore, due to the weak electron-withdrawing properties of the arylsilyl groups or heteroarylsilyl groups, the electronic state of the dopants can be altered, and the reduction and roll-off of the emission color wavelength can be limited or reduced (a phenomenon that reduces emission efficiency at high brightness).

[0228] Organic electroluminescent devices according to embodiments of this disclosure can achieve high efficiency and long lifespan.

[0229] The polycyclic compounds according to the embodiments of this disclosure can improve the lifespan and efficiency of organic electroluminescent devices.

[0230] As used herein, the term "and / or" includes any combination and all combinations of one or more of the related listed items. Expressions such as "at least one / at least one" before a column of elements modify the entire column of elements and not individual elements within that column.

[0231] As used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation rather than terms of degree, and are intended to account for inherent biases in measured or calculated values ​​that would be recognized by those skilled in the art. Furthermore, when describing embodiments of this disclosure, the use of “may” means “one or more embodiments of this disclosure.” As used herein, the terms “use,” “using,” and “used” can be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively. Additionally, the term “exemplary” is intended to refer to an instance or illustration.

[0232] Furthermore, any numerical range stated herein is intended to include all subranges of the same numerical precision falling within the stated range. For example, the range “1.0 to 10.0” is intended to include all subranges between the minimum value 1.0 and the maximum value 10.0 (and including endpoints), i.e., 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 stated herein is intended to include all lower numerical limits falling within it, and any minimum numerical limit stated in this specification is intended to include all higher numerical limits falling within it. Therefore, the applicant reserves the right to amend this specification (including the claims) to expressly state any subranges falling within the scope expressly stated herein.

[0233] Although exemplary embodiments of this disclosure have been described, it should be understood that this disclosure should not be limited to these exemplary embodiments. However, those skilled in the art can make various changes and modifications within the spirit and scope of the claimed disclosure.

Claims

1. Polycyclic compounds represented by the following formula 3: Formula 3 In Equation 3, Y is N, Z1 and Z2 are both B. R6 to R9 and R 23 To R 26 Each of the following is independently a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroarylsilyl group having 2 to 30 ring-forming carbon atoms, or R6 and R 26 Combined to form a ring, R 10 To R 22 Each of the following is independently a hydrogen atom, a deuterium atom, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a substituted or unsubstituted thiol group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, or R 14 With R 15 Combined to form a ring, and / or R 17 With R 18 Combined to form a ring, R6 to R9 and R 23 To R 26 One of them is -Si(Ra)3, or R6 and R 26 Together they form -Si(Ra)2-, and Ra is an aryl group, either substituted or unsubstituted, having 6 to 30 carbon atoms forming a ring, or a heteroaryl group, either substituted or unsubstituted, having 2 to 30 carbon atoms forming a ring. The term "substitution" refers to substitution by one or more substituents selected from the group consisting of: deuterium atom, halogen atom, cyano group, nitro group, hydroxyl group, alkyl group having 1 to 10 carbon atoms and alkoxy group having 1 to 10 carbon atoms.

2. The polycyclic compound of claim 1, wherein one of R6 to R9 is -Si(Ra)3.

3. The polycyclic compound of claim 1, wherein formula 3 is any one of the compounds represented in group 1 of the following compounds: Compound group 1 。 4. An organic electroluminescent device, comprising: First electrode; Hole transport region on the first electrode; The emission layer on the hole transport region; The electron transmission region on the emission layer; as well as The second electrode on the electron transport region, The first electrode and the second electrode each independently comprise Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, their compounds or mixtures thereof, or transparent metal oxides, and The emission layer comprises the polycyclic compound of any one of claims 1 to 3.

5. The organic electroluminescent device of claim 4, wherein the emitting layer is a delayed fluorescence emitting layer comprising a host and a dopant, and The dopant comprises the polycyclic compound.

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