Organic electroluminescent device

Abstract

An organic electroluminescent device includes a first electrode, a second electrode, and an emission layer disposed between the first electrode and the second electrode, wherein the emission layer includes a polycyclic compound having a fused ring system and represented by Formula 1 to achieve high efficiency and improved efficiency roll-off characteristics in an emission wavelength range: Formula 1

Description

[0001] Cross-reference to related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2020-0037415, filed on March 27, 2020, the entire contents of which are incorporated herein by reference. Background Technology

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

[0004] Organic light-emitting displays (OLEDs) are being actively developed as image display devices. Unlike liquid crystal displays (LCDs), OLEDs are so-called self-emissive display devices, in which holes and electrons injected from the first and second electrodes recombine in the emitting layer, and light-emitting organic compounds in the emitting layer emit light to realize the display.

[0005] Display applications require organic electroluminescent devices with high luminous efficiency and / or long lifetime, and new materials for organic electroluminescent devices that can reliably achieve these properties are needed.

[0006] In recent years, in order to implement efficient organic electroluminescent devices, technologies related to phosphorescence emission (which uses triplet energy) and / or delayed fluorescence emission (which uses singlet excitons generated by collisions of triplet excitons (triplet-triplet annihilation, TTA)) are being developed, and materials for thermally activated delayed fluorescence (TADF) are being developed. Summary of the Invention

[0007] One or more aspects of embodiments of this disclosure relate to organic electroluminescent devices that exhibit superior luminous efficiency.

[0008] One or more aspects of the embodiments of this disclosure relate to polycyclic compounds as materials for organic electroluminescent devices having high efficiency characteristics.

[0009] One or more exemplary embodiments of this disclosure provide an organic electroluminescent device comprising a first electrode, a second electrode disposed on the first electrode, and an emitting layer disposed between the first and second electrodes and comprising a polycyclic compound represented by Formula 1, wherein the first and second electrodes each independently comprise any one selected from silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), LiF, molybdenum (Mo), titanium (Ti), indium (In), zinc (Zn), tin (Sn), and ytterbium (Yb), compounds of two or more of them, mixtures of two or more of them, or oxides thereof:

[0010] Formula 1

[0011]

[0012] In Formula 1, n can be 1 or 2, Z can be a substituent including at least one fluorine group or at least one cyano group, or an aromatic cyclic group including at least one nitrogen atom as a cyclic atom, b1 and b3 can each be independently an integer selected from 1 to 4, b2 can be 1 or 2, and R1 to R3 can each be independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxygen group, 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 3 to 30 cyclic carbon atoms.

[0013] Z can be cyano, fluorine, alkyl substituted with at least one fluorine group, phenyl substituted with at least one cyano or at least one trifluoromethyl group, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl or substituted or unsubstituted triazine.

[0014] Equation 1 can be expressed by Equation 2 or Equation 3:

[0015] Formula 2

[0016]

[0017] Formula 3

[0018]

[0019] In Formula 3, Z1 and Z2 may each be a substituent comprising at least one fluorine group or at least one cyano group, or an aromatic cyclic group comprising at least one nitrogen atom as a cyclic atom; b4 may be 1 or 2; b5 may be an integer selected from 1 to 4; R4 and R5 may each be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxy group, 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 3 to 30 cyclic carbon atoms; and in Formulas 2 and 3, b1 to b3, R1 to R3 and Z may each be the same as those defined in Formula 1.

[0020] Equation 2 can be expressed by Equation 2-1:

[0021] Equation 2-1

[0022]

[0023] In Formula 2-1, f1 can be 1 or 2, Y1 to Y3 can each be a nitrogen atom or CW2 independently, W1 and W2 can each be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, and b1, b3, R1 and R3 can each be the same as those defined in Formula 2 independently.

[0024] Equation 3 can be expressed by Equation 3-1:

[0025] Equation 3-1

[0026]

[0027] In Equation 3-1, Y 11 To Y 16 Each can be an independent nitrogen atom or CW 13 g1 and g2 can each be 1 or 2 independently, W 11 To W 13 Each of them may be independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, and b1, b3, b5, R1, R3 and R5 may each be independently the same as those defined in Formula 3.

[0028] Z can be represented by any one of Z-1 to Z-13:

[0029]

[0030] In Z-10 to Z-13, Ph is phenyl. This refers to the location to be connected.

[0031] Equation 1 can be expressed by Equation 1-A or Equation 1-B:

[0032] Formula 1-A

[0033]

[0034] Formula 1-B

[0035]

[0036] In Equation 1-B, Z a and Z b Each can be a substituent comprising at least one fluorine group or at least one cyano group, or an aromatic cyclic group comprising at least one nitrogen atom as a cyclic atom, and in Formula 1-A, Z can be the same as that defined in Formula 1.

[0037] In some embodiments, the organic electroluminescent device may further include a capping layer on the second electrode, and the capping layer may have a refractive index of about 1.6 or greater.

[0038] The emission layer can be used to emit delayed fluorescence.

[0039] The emitting layer can be used to emit light with a center wavelength of about 430 nm to about 470 nm.

[0040] One or more exemplary embodiments of this disclosure provide polycyclic compounds represented by Formula 1. Attached Figure Description

[0041] The accompanying drawings are included to provide a further understanding of this disclosure, and are incorporated in and form a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the disclosure. In the drawings:

[0042] Figure 1 A cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present disclosure;

[0043] Figure 2 A cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present disclosure;

[0044] Figure 3 A cross-sectional view of an organic electroluminescent device according to an embodiment of the present disclosure is provided for illustrative purposes; and

[0045] Figure 4 A cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present disclosure. Detailed Implementation

[0046] This disclosure can be modified to have many alternative forms, and therefore the chosen embodiments will be illustrated and described in more detail in the accompanying drawings. However, it should be understood that this description is not intended to limit this disclosure to the specific forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

[0047] In this disclosure, when an element (or area, layer, section, etc.) is referred to as being "on" another element, "connected to" or "attached to" another element, it means that the element may be directly disposed on / connected to / attached to the other element, or a third element may be disposed between them. When an element is referred to as being "directly on" another element, "directly connected to" or "directly attached to" another element, there are no intermediate elements.

[0048] The same reference numerals refer to the same elements throughout the drawings, and repeated descriptions of them are not required. Furthermore, in the drawings, the thickness, proportions, and dimensions of elements may be exaggerated for the purpose of effectively describing the technical content.

[0049] Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” as used herein are intended to include the plural forms as well. The term “and / or” includes any and all combinations of one or more of the associated listed items. Furthermore, the use of “may” in describing embodiments of this disclosure refers to “one or more embodiments of this disclosure.”

[0050] 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. For example, without departing from the scope of exemplary embodiments of this disclosure, a first element may alternatively be referred to as a second element, and similarly, a second element may alternatively be referred to as a first element. Singular terms may include plural forms unless the context clearly indicates otherwise.

[0051] Furthermore, terms such as "below," "down," "above," and / or "up" are used to describe the relationships of the configurations shown in the accompanying drawings. These terms are used as relative concepts and are described with reference to the directions indicated in the accompanying drawings.

[0052] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms defined in common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant field, unless explicitly defined herein, and should not be interpreted in an idealized or overly formal sense.

[0053] It should be understood that the terms “include,” “including,” “comprise,” “comprising,” and / or “have” are intended to indicate the presence of the features, integers, steps, operations, elements, components, or combinations thereof stated in this disclosure, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

[0054] In the following description, an organic electroluminescent device according to embodiments of the present disclosure and the polycyclic compounds included therein will be described with reference to the accompanying drawings.

[0055] Figures 1 to 4 A cross-sectional view illustrating an organic electroluminescent device according to an embodiment of the present disclosure. (See reference...) Figures 1 to 4 In each of the organic electroluminescent devices 10 according to the embodiments, the first electrode EL1 and the second electrode EL2 are arranged to face each other, and the emission layer EML is disposed between the first electrode EL1 and the second electrode EL2.

[0056] In addition to the emitter layer EML, each of the organic electroluminescent devices 10 further includes a plurality of organic layers between the first electrode EL1 and the second electrode EL2. The plurality of organic layers may include a hole transport region HTR and an electron transport region ETR. For example, according to an embodiment, the organic electroluminescent device 10 may each 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 sequentially. In some embodiments, the organic electroluminescent device 10 may include a capping layer CPL disposed on the second electrode EL2.

[0057] and Figure 1 Compare, Figure 2 A cross-sectional view of the organic electroluminescent device 10 according to an embodiment is shown, wherein the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL, and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL. Figure 1 Compare, Figure 3 A cross-sectional view of the organic electroluminescent device 10 according to an embodiment is shown, wherein the hole transport region HTR includes a hole injection layer HIL, a hole transport layer HTL, and an electron blocking layer EBL, and the electron transport region ETR includes an electron injection layer EIL, an electron transport layer ETL, and a hole blocking layer HBL. Figure 2 Compare, Figure 4 A cross-sectional view of an organic electroluminescent device 10, including an encapsulation layer CPL disposed on the second electrode EL2, is shown.

[0058] The first electrode EL1 may be conductive. The first electrode EL1 may be formed of a metal alloy and / or a conductive compound. The first electrode EL1 may be an anode. In some embodiments, 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), and / 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, Mo, Ti, In, Zn, Sn, Yb, their compounds, or mixtures thereof (e.g., a mixture of Ag and Mg). In some embodiments, the first electrode EL1 may have a multilayer structure, including a reflective or transflective film formed from the aforementioned materials, and a transparent conductive film formed from indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but is not limited thereto. The thickness of the first electrode EL1 may be approximately [missing information]. to approximately For example, about to approximately

[0059] The hole transport region HTR is provided on the first electrode EL1. The hole transport region HTR may include at least one of a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer, and an electron blocking layer EBL. The thickness of the hole transport region HTR may be, for example, approximately [missing information - likely a number]. to approximately

[0060] The hole transport region (HTR) may have a single layer formed of a single material, a single layer formed of multiple different materials, or a multilayer structure comprising multiple layers formed of multiple different materials.

[0061] For example, the hole transport region HTR may have a single-layer structure of a hole injection layer HIL or a hole transport layer HTL, or it may have a single-layer structure formed of a hole injection material and a hole transport material. In some embodiments, the hole transport region HTR may have a single-layer structure formed of multiple different materials, or a structure in which the 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 stacked sequentially from the first electrode EL1, but the embodiments are not limited to this.

[0062] Hole transport regions (HTRs) can be formed using any suitable method, such as vacuum deposition, spin coating, casting, Langmuir-Brookett (LB) method, inkjet printing, laser printing, and / or laser-induced thermal imaging (LITI).

[0063] Hole injection layer HIL may include, for example, phthalocyanine compounds (such as copper phthalocyanine), N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine (DNTPD), 4,4',4”-[tris(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4',4”-tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4”-tris{N-(2-naphthyl)N-phenylamino}-triphenylamine (2-TNATA), poly(3,4-ethylenedioxythiophene) / poly(4-styrene). Poly(phenylene sulfonate) (PEDOT / PSS), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), polyaniline / camphor sulfonic acid (PANI / CSA), polyaniline / poly(4-styrene sulfonate) (PANI / PSS), N,N'-di(naphthyl-l-yl)-N,N'-diphenyl-benzidine (NPB), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium [tetra(pentafluorophenyl)borate], dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarboxynitrile (HAT-CN), etc.

[0064] The hole transport layer (HTL) may further include, for example, carbazole derivatives (such as N-phenylcarbazole and / or polyvinylcarbazole), fluorene derivatives, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), triphenylamine derivatives (such as 4,4',4”-tris(N-carbazolyl)triphenylamine (TCTA)), N,N'-bis(naphthyl-1-yl)-N,N'-diphenyl-benzidine (NPB), 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(N-carbazolyl)benzene (mCP), etc.

[0065] The thickness of the hole transport region (HTR) can be approximately to approximately For example, about to approximately The thickness of the hole injection layer (HIL) can be, for example, approximately... to approximately Furthermore, the thickness of the hole transport layer (HTL) can be approximately [missing information]. to approximately For example, the thickness of the electron blocking layer (EBL) can be approximately [missing information]. to approximately When the thicknesses of the hole transport region (HTR), hole injection layer (HIL), hole transport layer (HTL), and electron blocking layer (EBL) meet the above-mentioned ranges, satisfactory hole transport properties can be achieved without a significant increase in driving voltage.

[0066] In addition to the materials described above, the hole transport region (HTR) may further include a charge-generating material to increase conductivity. The charge-generating material may be substantially 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 selected from, but is not limited to, quinone derivatives, metal oxides, and cyano-containing compounds. Non-limiting examples of p-dopers include, but are not limited to, quinone derivatives (such as tetracyanoquinone dimethyl ether (TCNQ) and / or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinone dimethyl ether (F4-TCNQ)), metal oxides (such as tungsten oxide and / or molybdenum oxide), etc.

[0067] As described above, in addition to the hole injection layer (HIL) and the hole transport layer (HTL), the hole transport region (HTR) may further include at least one of a hole buffer layer and an electron blocking layer (EBL). The hole buffer layer can compensate for the resonant distance of the wavelength of light emitted from the emitter layer (EML) to increase the light emission efficiency. Materials that may be included in the hole transport region (HTR) may be included in the hole buffer layer. The electron blocking layer (EBL) is a layer used to prevent or reduce the injection of electrons from the electron transport region (ETR) into the hole transport region (HTR).

[0068] The emitter layer EML is provided on the hole transport region HTR. The thickness of the emitter layer EML can be, for example, approximately... to approximately or about to approximately The emitter layer (EML) can have a single layer formed from a single material, a single layer formed from multiple different materials, or a multilayer structure with multiple layers formed from multiple different materials.

[0069] In the organic electroluminescent device 10 of the embodiment, the emission layer EML may include the polycyclic compound of the embodiment.

[0070] In this description, the term "substituted or unsubstituted" may refer to an unsubstituted state or a state substituted by at least one substituent selected from the group consisting of: deuterium, halogen, cyano, nitro, amino, silyl, oxy, thio, sulfinyl, sulfonyl, carbonyl, boron, phosphine oxide, phosphine sulfide, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, and heterocyclic groups. In some embodiments, each of the listed substituents may be further substituted or unsubstituted. For example, biphenyl may be interpreted as aryl, or a phenyl group substituted with a phenyl group.

[0071] In this description, non-limiting examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0072] In this description, the alkyl group may be straight-chain, branched, or cyclic. The number of carbon atoms in the alkyl group may be 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Non-limiting examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyl 2-Hexyldecyl, 2-Octylide, n-Undecyl, n-Dodecyl, 2-Ethyldodecyl, 2-Butyldodecyl, 2-Hexyldodecyl, 2-Octylide, n-Tridecyl, n-Tetradecyl, n-Pentadedecyl, n-Hexadecyl, 2-Ethylhexadecyl, 2-Butylhexadecyl, 2-Hexylhexadecyl, 2-Octylide, n-Heptadedecyl, n-Octadedecyl, n-Nondecyl, n-Eicosyl, 2-Ethyleicosyl, 2-Butyleicosyl, 2-Hexyleicosyl, 2-Octylide, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, n-Iconodecyl, etc.

[0073] In this description, the aromatic ring group may be aryl or heteroaryl derived from an aromatic hydrocarbon ring.

[0074] In this description, the aryl group can be any 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. Non-limiting examples of aryl groups include phenyl, naphthyl, fluorenyl, anthracene, phenanthryl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, hexaphenyl, triphenylene, pyrene, benzofluoranthracene, 1,2-benzophenanthryl, etc.

[0075] In this description, the heteroaryl group may include at least one of boron (B), oxygen (O), nitrogen (N), phosphorus (P), silicon (Si), and sulfur (S) as a heteroatom. When the heteroaryl group contains two or more heteroatoms, the two or more heteroatoms may be the same or different from each other. The heteroaryl group may be a monocyclic heteroaryl or a polycyclic heteroaryl. The number of cyclic carbon atoms in the heteroaryl group may be 2 to 30, 2 to 20, or 2 to 10. Alternatively, the number of cyclic carbon atoms in the heteroaryl group may be 3 to 30, 3 to 20, or 3 to 10. Non-limiting examples of heteroaryl groups include thienyl, furanyl, pyrrolyl, imidazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridineyl, pyridazinyl, quinolinyl, quinazolinyl, quinoxazinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolinyl, indolyl, carbazoleyl, N-arylcarbazoleyl, N-heteroarylcarbazoleyl, N-alkylcarbazoleyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazoleyl, benzothiaphenyl, dibenzothiaphenyl, thiaphenothiaphenyl, benzofuranyl, phenanthrololinyl, thiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, thiadiazolyl, phenthiazolyl, dibenzothiazolyl, dibenzothiazolyl, dibenzofuranyl, etc.

[0076] In this description, the oxygen group may be an alkoxy or an aryloxy group.

[0077] In this description, alkoxy groups may include straight-chain, branched, or cyclic alkyl groups. The number of carbon atoms in an alkoxy group is not particularly limited, but may, for example, be 1 to 20 or 1 to 10. Non-limiting examples of alkoxy groups include methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, pentoxy, hexoxy, octoxy, nonoxy, decoxy, benzyloxy, etc.

[0078] In this description, This refers to the location to be connected.

[0079] The emitting layer EML of the organic electroluminescent device 10 of the embodiment may include a polycyclic compound represented by Formula 1 of the embodiment:

[0080] Formula 1

[0081]

[0082] In Formula 1, n can be 1 or 2. For example, when n is 1, the polycyclic compound of the embodiment can be at least a 5-membered ring system formed by fused 4-membered ring groups to a benzene ring. When n is 2, the polycyclic compound of the embodiment can be at least a 9-membered ring group formed by fused two 4-membered ring groups to (the same) benzene ring.

[0083] In Formula 1, Z can be a substituent including at least one fluorine group or at least one cyano group, or an aromatic cyclic group including at least one nitrogen atom as a cyclic atom.

[0084] The substituent comprising at least one fluorine group or at least one cyano group may be cyano, fluorine, or, for example, an aryl or alkyl group comprising at least one cyano and / or fluorine group as a substituent. For example, when Z comprises a fluorine group as a substituent, Z may be trifluoromethyl, a phenyl substituted with trifluoromethyl, or a phenyl substituted with a fluorine group. When Z comprises a cyano group as a substituent, Z may be a phenyl substituted with a cyano group. However, this is an example, and the implementation is not limited thereto.

[0085] Z can be cyano, fluorine, alkyl substituted with at least one fluorine group, phenyl substituted with at least one cyano or at least one trifluoromethyl group, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, or substituted or unsubstituted triazine. Z can be an electron-withdrawing group.

[0086] For example, Z can be a fluorinated or cyano group. Z can be a fluorinated substituted methyl group (e.g., fluoromethyl), or a phenyl group substituted with one or two cyano groups (e.g., dicyanophenyl). Z can be a phenyl group substituted with one or two trifluoromethyl groups (e.g., trifluoromethylphenyl or bis-trifluoromethylphenyl). Z can be a triazine group substituted with two phenyl groups, a pyrimidinyl group substituted with two phenyl groups, or a pyridinyl group substituted with two phenyl groups.

[0087] In Equation 1, b2 can be 1 or 2. b1 and b3 can each be an integer selected from 1 to 4 independently. When b2 is 2, multiple R2s can be the same or different from each other. When b1 is 2 or a larger integer, multiple R1s can be the same or different from each other. When b3 is 2 or a larger integer, multiple R3s can be the same or different from each other.

[0088] R1 to R3 can each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxygen 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 3 to 30 cyclic carbon atoms.

[0089] For example, when b1 is 4, multiple R1s can be the same. For example, all four R1s can be deuterium atoms. When b3 is 2, multiple R3s can be the same. For example, both R3s can be deuterium atoms. However, this is just an example, and the implementation is not limited to this.

[0090] Meanwhile, Z can be represented by any one of Z-1 to Z-13. The polycyclic compound of the embodiment may include any one of Z-1 to Z-13 as an electron-withdrawing group.

[0091]

[0092] In Z-10 to Z-13, Ph is phenyl.

[0093] According to the embodiments, the polycyclic compounds can be used as luminescent materials to emit wavelengths (λ) from the emission center. max Deep blue light in the wavelength range of about 470 nm or less. For example, the polycyclic compound of the embodiment represented by Formula 1 can be a luminescent material having a central emission wavelength in the wavelength range of about 430 nm to about 470 nm.

[0094] According to the embodiments, Formula 1 can be represented by Formula 2. Formula 2 shows the case where n is 1, and the polycyclic compound of the embodiments is a 5-membered fused aromatic ring system.

[0095] Formula 2

[0096]

[0097] In Equation 2, b1 to b3, R1 to R3 and Z can each independently have the same description as those described in Equation 1.

[0098] For example, b1 can be 4, and each of the four R1 atoms can be either a hydrogen atom or a deuterium atom, and they can be the same. b2 can be 2, and each of the two R2 atoms can be either a hydrogen atom or a deuterium atom, and the two R2 atoms can be the same. b3 can be 4, and each of the four R3 atoms can be either a hydrogen atom or a deuterium atom, and they can be the same. Z is an electron-withdrawing group, and it can include at least one nitrogen atom or a fluorine atom.

[0099] In some implementations, equation 2 can be represented by equation 2-1:

[0100] Equation 2-1

[0101]

[0102] In Equation 2-1, Y1 to Y3 can each be an independent nitrogen atom or CW2. For example, Y1 to Y3 can all be nitrogen atoms or CW2. One or two of Y1 to Y3 can be nitrogen atoms. When Y1 to Y3 are all CW2, or when two of Y1 to Y3 are CW2, the multiple W2 atoms can be the same or different.

[0103] W1 and W2 can each independently be a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms.

[0104] When Y1 to Y3 are all CW2, or when two of Y1 to Y3 are CW2, the multiple W2 groups can all be hydrogen atoms. For example, when Y1 to Y3 are all CW2, the cyclic groups including Y1 to Y3 can be substituted phenyl groups. The cyclic groups including Y1 to Y3 can be phenyl groups substituted with at least one cyano group or at least one trifluoromethyl group.

[0105] When all Y1 to Y3 are nitrogen atoms, the cyclic group including Y1 to Y3 can be a substituted or unsubstituted triazine group. When two of Y1 to Y3 are nitrogen atoms, the cyclic group including Y1 to Y3 can be a substituted or unsubstituted pyrimidinyl group. When one of Y1 to Y3 is a nitrogen atom, the cyclic group including Y1 to Y3 can be a substituted or unsubstituted pyridinyl group.

[0106] In Equation 2-1, f1 can be 1 or 2. When f1 is 2, the two W1s can be the same or different from each other. For example, f1 can be 2, and the two W1s can simultaneously be cyano, fluoro, trifluoromethyl, or phenyl.

[0107] In Equation 2-1, b1, b3, R1, and R3 can each independently have the same description as those described in Equation 2.

[0108] In the embodiments, Equation 1 can be represented by Equation 3. Equation 3 shows the case where n is 2, and the polycyclic compound of the embodiment is a 9-membered aromatic fused ring system.

[0109] Formula 3

[0110]

[0111] In Formula 3, Z1 and Z2 may each independently be a substituent comprising at least one fluorine group or at least one cyano group, or an aromatic cyclic group comprising at least one nitrogen atom as a cyclic atom. Z1 and Z2 may each independently be a cyano group, a fluorine group, an alkyl group substituted with at least one fluorine group, a phenyl group substituted with at least one cyano group, at least one fluorine group or at least one trifluoromethyl group, a substituted or unsubstituted pyridyl group, a substituted or unsubstituted pyrimidinyl group, or a substituted or unsubstituted triazine group. Z1 and Z2 may each be an electron-withdrawing group. Z1 and Z2 may each independently be represented by one of Z-1 to Z-13.

[0112] In some embodiments, Z1 and Z2 may be identical to each other. For example, Z1 and Z2 may simultaneously be cyano, fluoro, or trifluoromethyl. For example, Z1 and Z2 may simultaneously be a phenyl group substituted with one or two cyano groups, a phenyl group substituted with one or two fluoro groups, or a phenyl group substituted with one or two trifluoromethyl groups. For example, Z1 and Z2 may simultaneously be a triazine group substituted with two phenyl groups, a pyrimidinyl group substituted with two phenyl groups, or a pyridinyl group substituted with two phenyl groups.

[0113] In some embodiments, Z1 and Z2 may be different from each other. For example, Z1 and Z2 may be a phenyl group substituted with one cyano group and a phenyl group substituted with one fluorine group, respectively. For example, Z1 and Z2 may be a phenyl group substituted with two cyano groups and a phenyl group substituted with one cyano group, respectively. For example, Z1 and Z2 may be a phenyl group substituted with one fluorine group and a phenyl group substituted with two cyano groups, respectively. For example, Z1 and Z2 may be a phenyl group substituted with one cyano group and a phenyl group substituted with one cyano group, respectively. For example, Z1 and Z2 may be a phenyl group substituted with two phenyl groups and a phenyl group substituted with one cyano group, respectively. For example, Z1 and Z2 may be a phenyl group substituted with two phenyl groups and a phenyl group substituted with one cyano group, respectively.

[0114] In Equation 3, b4 can be 1 or 2. When b4 is 2, the two R4s can be the same or different from each other.

[0115] b5 can be an integer selected from 1 to 4. When b5 is an integer of 2 or greater, multiple R5s can all be the same or different from each other.

[0116] R4 and R5 can each independently be a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted oxygen 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 3 to 30 cyclic carbon atoms.

[0117] For example, when b4 is 2, both R4 atoms can be either hydrogen or deuterium atoms. When b5 is 4, all four R5 atoms can be either hydrogen or deuterium atoms.

[0118] In Equation 3, b1 to b3, R1 to R3 and Z can each independently have the same description as those described in Equation 1.

[0119] In some implementations, Equation 3 can be represented by Equation 3-1:

[0120] Equation 3-1

[0121]

[0122] In some implementations, in Equation 3-1, Y 11 To Y 16 Each can be an independent nitrogen atom or CW 13 Y 11 To Y 16 They can all (e.g., simultaneously) be nitrogen atoms, or CW 13 For example, including Y 11 To Y 13 cyclic groups and including Y 14 To Y 16 The cyclic groups may all (e.g., simultaneously) be substituted or unsubstituted triazine groups or substituted or unsubstituted phenyl groups. In some embodiments, Y 11 To Y 13 The two atoms in Y can be nitrogen atoms. 14 To Y 16 Two of them can be nitrogen atoms. For example, including Y 11 To Y 13 cyclic groups and including Y 14 To Y 16 The cyclic groups may all (e.g., simultaneously) be substituted or unsubstituted pyrimidine groups. In some embodiments, Y 11 To Y 13 One of them can be a nitrogen atom, and Y 14 To Y 16 One of them can be a nitrogen atom. For example, it includes Y. 11 To Y 13 cyclic groups and including Y 14 To Y 16 The cyclic groups may all (e.g., simultaneously) be substituted or unsubstituted pyridyl groups.

[0123] g1 and g2 can each be 1 or 2 independently. When g1 is 2, the two Ws... 11 They can be the same or different. When g2 is 2, the two Ws... 12 They may be the same as or different from each other.

[0124] W 11 To W 13 Each of them can be independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms.

[0125] For example, W 11 and W 12 Each can be independently cyano, fluoro, trifluoromethyl, or phenyl. When g1 is 2, the two W groups... 11 Each can be (e.g., simultaneously) cyano, fluoro, trifluoromethyl, or phenyl. When g2 is 2, the two Ws... 12Each of them (for example, simultaneously) can be cyano, fluoro, trifluoromethyl, or phenyl.

[0126] In some implementations, Y 11 To Y 13 cyclic groups and including Y 14 To Y 16 At least one of the cyclic groups may be a substituted or unsubstituted phenyl group. For example, including Y 11 To Y 13 cyclic groups and including Y 14 To Y 16 The cyclic groups may each (e.g., simultaneously) be substituted or unsubstituted phenyl groups. In some embodiments, Y is included. 11 To Y 13 cyclic groups and including Y 14 To Y 16 One of the cyclic groups can be a substituted or unsubstituted phenyl group, while the other can be a nitrogen-containing cyclic group. For example, including Y 11 To Y 13 cyclic groups and including Y 14 To Y 16 One of the cyclic groups is a substituted or unsubstituted phenyl group, while the other cyclic group is a substituted or unsubstituted triazine group, a substituted or unsubstituted pyrimidinyl group, or a substituted or unsubstituted pyridinyl group. When Y is included... 11 To Y 13 cyclic groups and including Y 14 To Y 16 When one of the cyclic groups is a nitrogen-containing cyclic group, the nitrogen-containing cyclic group can be substituted by a phenyl group.

[0127] For example, including Y 11 To Y 13 The cyclic group can be a phenyl group substituted with a cyano group, and includes Y. 14 To Y 16 The cyclic group can be a phenyl group substituted with a fluorine group. For example, including Y 11 To Y 13 The cyclic group can be a phenyl group substituted with a fluorine group, and includes Y. 14 To Y 16 The cyclic group can be a phenyl group substituted with two cyano groups. For example, including Y 11 To Y 13 The cyclic group can be a phenyl group substituted with two cyano groups, and includes Y. 14 To Y 16 The cyclic group can be a phenyl group substituted with two fluorine groups. For example, including Y 11 To Y 13 The cyclic group can be a phenyl group substituted with a cyano group, and includes Y. 14 To Y 16The cyclic group can be a phenyl group substituted with one or two trifluoromethyl groups. For example, including Y 11 To Y 13 The cyclic group can be a triazine group substituted with two phenyl groups, a pyrimidinyl group substituted with two phenyl groups, or a pyridinyl group substituted with two phenyl groups, and includes Y. 14 To Y 16 The cyclic group can be a phenyl group substituted with a cyano group.

[0128] In Equation 3-1, b1, b3, b5, R1, R3, and R5 can each independently have the same description as those described in Equation 3.

[0129] According to the implementation method, Formula 1 can be represented by Formula 1-A or Formula 1-B. In Formula 1-A and Formula 1-B, "D" represents a deuterium atom.

[0130] The polycyclic compound of the embodiment can be a 5-membered fused ring system, and Formula 1-A shows the case where n in Formula 1 is 1. In Formula 1-A, b1 is 4, b2 is 2, b3 is 4, and multiple R1 to R3 are all deuterium atoms. For example, in Formula 1, when four R1, two R2, and four R3 are all deuterium atoms, it can be represented by Formula 1-A.

[0131] Formula 1-A

[0132]

[0133] In Equation 1-A, Z can be the same as that described in Equation 1.

[0134] Formula 1-B illustrates the case where n is 2 in Formula 1. The polycyclic compound of the embodiment is a 9-membered fused ring system having a deuterium atom as a substituent. In Formula 1-B, Z1 and Z2 may both (e.g., simultaneously) be electron-withdrawing groups. For example, except for Z (which is an electron-withdrawing group in Formula 1), Formula 1-B may all be substituted with deuterium atoms (e.g., completely deuterated).

[0135] Formula 1-B

[0136]

[0137] Z a and Z b Each can be an independent substituent comprising at least one fluorine group or at least one cyano group, or an aromatic cyclic group comprising at least one nitrogen atom as a cyclic atom. In some embodiments, Z a and Z b They can be the same as each other. For example, Z a and Z b They can all (e.g., simultaneously) be cyano groups.

[0138] The polycyclic compounds of the embodiments may be 5- or 9-membered fused-ring systems, which include electron-withdrawing groups as substituents and have a nitrogen atom and a carbonyl group as cyclic atoms to reduce efficiency degradation. Without being limited by the correctness of any theory or explanation, it is believed that the polycyclic compounds of the embodiments can reduce efficiency degradation by delocalizing multiple resonances in the 5- or 9-membered aromatic fused-ring system (e.g., due to increased resonance delocalization). Therefore, the polycyclic compounds of the embodiments included in the emitting layer of the organic electroluminescent device of the embodiments can help improve the efficiency degradation phenomenon.

[0139] The polycyclic compound in the embodiments may be any of the compounds represented in compound group 1. The organic electroluminescent device 10 according to the embodiments may include at least one polycyclic compound represented in compound group 1 in the emitting layer EML.

[0140] Compound group 1

[0141]

[0142]

[0143]

[0144]

[0145] The polycyclic compound in the embodiments can be a thermally activated delayed fluorescence (TADF) material. The polycyclic compound in the embodiments represented by Formula 1 can be a blue thermally activated delayed fluorescence dopant.

[0146] In the organic electroluminescent device 10 of the embodiment, the emitting layer EML can be used to emit delayed fluorescence. For example, the emitting layer EML can be used to emit thermally activated delayed fluorescence (TADF).

[0147] In embodiments, the emission layer EML may include a host and a dopant, and may include a polycyclic compound as a dopant. For example, in the organic electroluminescent device 10 of an embodiment, the emission layer EML may include a host for delayed fluorescence emission and a dopant for delayed fluorescence emission, and may include a polycyclic compound as a dopant for delayed fluorescence emission. In some embodiments, the emission layer EML may include at least one of the polycyclic compounds represented by compound group 1 as a thermally activated delayed fluorescence dopant.

[0148] In this embodiment, the emission layer EML may be a delayed fluorescence emission layer, and the emission layer EML may comprise any suitable host material and polycyclic compound of the embodiment. For example, in this embodiment, the polycyclic compound may be used as a TADF dopant.

[0149] The emitter layer EML can include any suitable host material. For example, the emitter layer EML can include, as a host material, tris(8-hydroxyquinoline)aluminum (Alq3), 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP), 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-phenylbenzimidazolyl-2-yl)benzene (TPBi), 3-tert-butyl-9,10-bis(naphthyl-2-yl)anthracene (TBADN), stilbene aromatic hydrocarbons (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethylbiphenyl (CDBP), 2-methyl-9 Examples of suitable host materials include 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), 2,8-bis(diphenylphospho)dibenzofuran (PPF), 3,3'-bis(N-carbazolyl)-1,1'-biphenyl (mCBP), and 1,3-bis(carbazolyl-9-yl)benzene (mCP). However, embodiments of this disclosure are not limited thereto, and any suitable delayed fluorescence host material may be included in addition to the proposed host materials.

[0150] In the organic electroluminescent device 10 of the embodiment, the emitting layer EML may further comprise any suitable dopant material. In the embodiment, the emitting layer EML may further 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-tetra-tert-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1'-dipyrene, 1,4-dipyrenebenzene, 1,4-bis(N,N-diphenylamino)pyrene, etc.).

[0151] In some embodiments, the organic electroluminescent device 10 of the embodiment may include a plurality of emission layers (EMLs). The plurality of emission layers (EMLs) may be stacked sequentially, and for example, the organic electroluminescent device 10 including a plurality of emission layers (EMLs) may be used to emit white light. The organic electroluminescent device 10 including a plurality of emission layers (EMLs) may be an organic electroluminescent device having a series structure. When the organic electroluminescent device 10 includes a plurality of emission layers (EMLs), at least one emission layer (EML) may include a polycyclic compound of the embodiment.

[0152] exist Figures 1 to 4 In the organic electroluminescent device 10 of the embodiments described herein, an electron transport region (ETR) is provided on an emitter layer (EML). The electron transport region (ETR) may include at least one of a hole blocking layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL), but embodiments of this disclosure are not limited thereto.

[0153] The electron transport region (ETR) can have a single layer formed of a single material, a single layer formed of multiple different materials, or a multilayer structure comprising multiple layers formed of multiple different materials.

[0154] For example, the electron transport region (ETR) may have a single-layer structure of an electron injection layer (EIL) or an electron transport layer (ETL), or it may have a single-layer structure formed of an electron injection material and an electron transport material. In some embodiments, the ETR may have a single-layer structure formed of multiple different materials, or it may have a structure in which the electron transport layer (ETL) / electron injection layer (EIL) and the hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL) are stacked sequentially from the emitter layer (EML), but is not limited thereto. The thickness of the ETR may be, for example, approximately [missing information - likely a number]. to approximately

[0155] The electron transport region (ETR) can be formed using any suitable method, such as vacuum deposition, spin coating, casting, Langmuir-Brookett (LB) method, inkjet printing, laser printing, laser-induced thermal imaging (LITI), etc.

[0156] When the electron transport region (ETR) includes an electron transport layer (ETL), the ETL may include anthracene compounds. However, embodiments of this disclosure are not limited thereto, and the ETL may include, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 1,3,5-tris[(3-pyridyl)-benzene-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazol-1-yl)phenyl)-9,10-dinaphthylanthracene, 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-hydroxy)aluminum (BAlq), bis(benzoquinoline-10-hydroxy)beryllium (Bebq2), 9,10-bis(naphth-2-yl)anthracene (ADN), 1,3-bis[3,5-bis(pyridin-3-yl)phenyl]benzene (BmPyPhB), or mixtures thereof. The thickness of the electron transport layer (ETL) can be approximately to approximately And it can be, for example, about to approximately When the thickness of the electron transport layer (ETL) meets the above-mentioned range, satisfactory electron transport properties can be obtained without a significant increase in the driving voltage.

[0157] When the electron transport region (ETR) includes an electron injection layer (EIL), the EIL may include, but is not limited to, metal halides (such as LiF, NaCl, CsF, RbCl, and / or RbI), lanthanides (such as Yb), metal oxides (such as Li₂O and / or BaO), or lithium 8-hydroxyquinoline (LiQ). In some embodiments, the EIL may be formed from a mixture of an electron injection material and an insulating organometallic salt. The insulating organometallic salt may be a material having a band gap of about 4 eV or higher. The insulating organometallic salt may include, for example, metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates, and / or metal stearates. The thickness of the EIL may be approximately [missing information - likely a value]. to approximately , or about to approximately When the thickness of the electron injection layer (EIL) meets the above-mentioned range, satisfactory electron injection properties can be obtained without a significant increase in driving voltage.

[0158] As described above, the electron transport region (ETR) may include a hole blocking layer (HBL). The hole blocking layer (HBL) may include, for example, at least one of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and 4,7-diphenyl-1,10-phenanthroline (Bphen), but is not limited thereto.

[0159] The second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 can be a common electrode or a cathode. The second electrode EL2 can be a transmission electrode, a transmission-reflection electrode, or a reflection electrode. When the second electrode EL2 is a transmission electrode, the second electrode EL2 may include a transparent metal oxide, such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO).

[0160] When the second electrode EL2 is a transmissive or reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, In, Zn, Sn, Yb, their compounds, or mixtures thereof (e.g., a mixture of Ag and Mg). In some embodiments, the second electrode EL2 may have a multilayer structure, which includes a reflective or transmissive film formed from the above materials, and a transparent conductive film formed from indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc.

[0161] In some embodiments, the second electrode EL2 may be connected to an auxiliary electrode. When the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 may be reduced.

[0162] In some embodiments, the capping layer CPL may be further disposed on the second electrode EL2 of the organic electroluminescent device 10 of the embodiment. The capping layer CPL may include, for example, α-NPD, NPB, TPD, m-MTDATA, Alq3, CuPc, N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine (TPD15), 4,4',4"-tris(carbazole-9-yl)triphenylamine (TCTA), etc. However, the embodiments are not limited thereto, and the capping layer CPL may include amine compounds. For example, the capping layer CPL may include at least one of compounds CPL1 and CPL2:

[0163]

[0164] In some implementations, the capping layer CPL may have a refractive index of about 1.6 or greater. For example, for light with a wavelength range of about 550 nm to about 600 nm, the capping layer CPL may have a refractive index of about 1.6 or greater.

[0165] The compounds and organic electroluminescent devices according to embodiments of the present disclosure will be described in more detail below with reference to examples and comparative examples. The examples are illustrative only and the scope of the present disclosure is not limited thereto.

[0166] Example

[0167] 1. Polycyclic compounds in the synthesis examples

[0168] First, the process for synthesizing the polycyclic compounds according to this embodiment will be described in more detail with respect to compounds 1, 15, and 21 as examples. The process for synthesizing the polycyclic compounds is provided as an example, and the process for synthesizing the compounds according to embodiments of this disclosure is not limited to the examples.

[0169] (1) Synthesis of compound 1

[0170] Compound 1 according to the examples can be synthesized, for example, by reactions 1-1 to 1-4.

[0171] Synthetic intermediate compound A

[0172] Intermediate compound A is synthesized via reaction 1-1

[0173] Reaction 1-1

[0174]

[0175] Dimethyl 2-chloro-5-iodophthalate (30 g, 85 mmol), Cu(OAc)₂ (0.31 g, 1.7 mmol), Ph₃PO₄ (0.95 g, 3.4 mmol), and Ag₂O (19.7 g, 85 mmol) were added to DMF (280 mL), and the mixture was heated and stirred at 130 °C for 15 hours. Water was added, and the mixture was filtered through diatomaceous earth (Celite) for liquid separation, and the organic layer was concentrated. Purification was performed by silica gel column chromatography to obtain intermediate compound A (20.3 g, 94% yield).

[0176] Synthetic intermediate compound B

[0177] Intermediate compound B is synthesized via reaction formula 1-2:

[0178] Reaction 1-2

[0179]

[0180] Intermediate compound A (20 g, 80 mmol), diphenylamine (15 g, 88 mmol), Cu (1.5 g, 24 mmol), CuI (0.76 g, 4 mmol), and K₂CO₃ (0.77 g, 12 mmol) were added to o-dichlorobenzene (ODCB, 320 mL), and the mixture was heated and stirred at 160 °C for 8 hours. Water was added, and the mixture was filtered through diatomaceous earth (Celite) for liquid separation, and the organic layer was concentrated. Purification was performed by silica gel column chromatography to obtain intermediate compound B (27 g, 87% yield).

[0181] Synthetic intermediate compound C

[0182] Intermediate compound C is synthesized via reaction formulas 1-3:

[0183] Reaction 1-3

[0184]

[0185] Intermediate compound B (25 g, 65 mmol) and NaOH (5.2 g, 130 mmol) were added to ethanol (EtOH, 300 mL) and pure water (300 mL), and stirred at room temperature for 2 hours. Toluene was added for liquid separation, and the organic layer was concentrated to obtain intermediate compound C (22 g, 95% yield).

[0186] Synthetic compound 1

[0187] Compound 1 was synthesized via reactions 1-4:

[0188] Reaction 1-4

[0189]

[0190] Intermediate compound C (2.9 g, 8.0 mmol), SOCl2 (4.3 g, 8.4 mmol), and DMF (0.80 mL) were added to CH2Cl2 (80 mL), and the mixture was heated to reflux for 3 hours. Subsequently, tin(IV) chloride (SnCl4, 16.2 mL, 8.4 mmol) was added, and the mixture was further heated to reflux for 3 hours. After cooling to room temperature, the product was added dropwise to 1 M NaOH for liquid separation, and the organic layer was concentrated. Purification was performed by silica gel column chromatography to obtain compound 1 (2.20 g, 85% yield).

[0191] (1) Synthesize compound 15

[0192] Compound 15 according to the examples can be synthesized, for example, by reactions 2-1 to 2-4:

[0193] Synthetic intermediate compound D

[0194] Intermediate compound D is synthesized via reaction 2-1:

[0195] Reaction 2-1

[0196]

[0197] Dimethyl 5-bromo-2-iodophthalate (15 g, 38 mmol), N 1 N 3 Diphenylphenyl-1,3-diamine (4.9 g, 19 mmol), Cu (0.15 g, 0.16 mmol), CuI (0.19 g, 0.64 mmol), and K₂CO₃ (5.3 g, 38 mmol) were added to ODCB (320 mL), and the mixture was heated and stirred at 80 °C for 2 hours. Water was added, and the mixture was filtered through diatomaceous earth (Celite) for liquid separation, and the organic layer was concentrated. Purification was performed by silica gel column chromatography to obtain intermediate compound D (11 g, 75% yield).

[0198] Synthetic intermediate compound E

[0199] Intermediate compound E is synthesized via reaction 2-2:

[0200] Reaction 2-2

[0201]

[0202] Intermediate compound D (11 g, 14 mmol) and NaOH (2.3 g, 56 mmol) were added to 150 mL of ethanol and 150 mL of pure water, and the mixture was heated and stirred at room temperature for 2 hours. Toluene was added for liquid separation, and the organic layer was concentrated to obtain intermediate compound E (9.9 g, 95% yield).

[0203] Synthetic intermediate compound F

[0204] Intermediate compound F is synthesized via reaction 2-3:

[0205] Reaction 2-3

[0206]

[0207] Intermediate compound E (6.0 g, 8.04 mmol), SOCl2 (4.26 g, 8.44 mmol), and DMF (0.8 mL) were added to CH2Cl2 (80 mL), and the mixture was heated to reflux for 3 hours. Subsequently, tin(IV) chloride (SnCl4, 16.2 mL, 8.44 mmol) was added, and the mixture was further heated to reflux for 3 hours. After cooling to room temperature, the product was added dropwise to 1 M NaOH for liquid separation, and the organic layer was concentrated. Purification by silica gel column chromatography yielded intermediate compound F (4.06 g, 75% yield).

[0208] Synthetic compound 15

[0209] Compound 15 was synthesized via reaction 2-4:

[0210] Reaction 2-4

[0211]

[0212] Intermediate compound F (9.8 g, 15 mmol), 4-bromobenzonitrile (4.7 g, 32 mmol), tris(dibenzylacetone)dipalladium(0) (Pd2(dba)3, 0.27 g, 0.29 mmol), tri-tert-butylphosphine tetrafluoroborate ([P(tBu)3]HBF4, 0.34 g, 1.2 mmol), and sodium tert-butoxide (NaOtBu, 2.1 g, 22 mmol) were added to toluene (200 mL), and the mixture was heated and stirred at 80 °C for 2 hours. Water was added, and the mixture was filtered through diatomaceous earth (Celite) for liquid separation, and the organic layer was concentrated. Purification was performed by silica gel column chromatography to obtain compound 15 (7.3 g, 70% yield).

[0213] (2) Synthesis of compound 21

[0214] Compound 21 according to the examples can be synthesized, for example, by reaction 3:

[0215] Reaction 3

[0216]

[0217] Intermediate compound F (9.8 g, 15 mmol), (4,6-diphenyl-1,3,5-triazin-2-yl)boronic acid (8.8 g, 32 mmol), tris(dibenzylacetone)dipalladium(0) (Pd2(dba)3, 0.27 g, 0.29 mmol), tri-tert-butylphosphine tetrafluoroborate ([P(tBu)3]HBF4, 0.34 g, 1.16 mmol), and sodium tert-butoxide (NaOtBu, 2.1 g, 22 mmol) were added to toluene (200 mL), and the mixture was heated and stirred at 80 °C for 2 hours. Water was added, and the mixture was filtered through diatomaceous earth (Celite) for liquid separation, and the organic layer was concentrated. Purification was performed by silica gel column chromatography to obtain compound 21 (10 g, 69% yield).

[0218] 2. Evaluation of polycyclic compounds and fabrication and evaluation of organic electroluminescent devices.

[0219] The following evaluation assesses the luminescence properties of an organic electroluminescent device comprising a polycyclic compound from one embodiment and an embodiment in which the polycyclic compound from one embodiment is included in the emitting layer. A method for manufacturing the organic electroluminescent device for evaluation is described below.

[0220] Organic electroluminescent devices of Examples 1 to 3 were fabricated using compounds 1, 15, and 21 as dopant materials for the emission layer, respectively. Comparative Examples 1 and 2 are organic electroluminescent devices fabricated using comparative compounds X-1 and X-2 as dopant materials for the emission layer, respectively.

[0221] The compounds used in Examples 1 to 3 and Comparative Examples 1 and 2 are shown in Table 1:

[0222] Table 1

[0223]

[0224] Evaluate the luminescent properties of compounds

[0225] A 5.0 mM toluene solution was prepared for each of the Examples and Comparative Examples, and the luminescence properties of each Example and Comparative Example were evaluated using a JASCO V-670 spectrometer. The emission spectra were measured at room temperature and 77 K. Furthermore, the photoluminescence quantum yield (PLQY) of the 5.0 mM toluene solution was measured using a HAMAMATSU Quantaurus-QY spectra. Table 2 shows the maximum emission wavelength (λ) in the emission spectra measured at room temperature. max ) and the full width at half maximum (FWHM) in the emission spectrum.

[0226] Table 2

[0227] Compound 1 460 35 89 Compound 15 467 27 91 Compound 21 465 20 88 Compare compound X-1 464 37 89 Compare compounds X-2 440 45 30

[0228] Referring to Table 2, it can be seen that compounds 1, 15, and 21, which are polycyclic compounds used in the embodiments, each have a maximum emission wavelength of about 470 nm or less and emit deep blue light from it. The full width at half maximum (FWHM) of the emission spectra of compounds 1, 15, and 21, which are polycyclic compounds used in the embodiments, has been shown to be narrow to about 35 nm or less. Furthermore, compared with comparative compound X-2, compounds 1, 15, and 21 of the embodiments each have a large photoluminescence quantum efficiency (PLQY) value, and therefore it can be seen that the luminescence efficiency is excellent.

[0229] Comparative compounds X-1 and X-2 each have a maximum emission wavelength of approximately 470 nm or less, thus emitting deep blue light. However, it can be seen that comparative compounds X-1 and X-2 each have a full width at half maximum (FWHM) of approximately 37 nm or greater, and the comparative compounds have a larger FWHM than the example compounds. For example, it can be seen that the light emitted by the comparative compounds has lower color purity than that emitted by the example compounds. Furthermore, it can be seen that comparative compound X-2 has a lower photoluminescence quantum efficiency (PLQY) than that emitted by the example compounds.

[0230] The polycyclic compound of the embodiment includes at least one electron-withdrawing group as a substituent, thereby improving the efficiency degradation and emitting deep blue light with high color purity compared with the comparative compound.

[0231] Manufacturing organic electroluminescent devices

[0232] As the first electrode, ITO is patterned on a glass substrate to approximately [size missing]. The thickness was determined by rinsing with ultrapure water, ultrasonic cleaning, UV irradiation for 30 minutes, and then ozone treatment. Afterwards, HAT-CN was deposited onto... The thickness of α-NPD will be deposited onto The thickness of the mCP will be deposited onto the substrate. The thickness is increased to form a hole transport region.

[0233] Next, in the formation of each emission layer, the polycyclic compound or comparative compound of the embodiment and mCBP are co-deposited at a ratio of 1:99 to form a thickness of [thickness missing]. The layers. For example, the emission layers formed by co-deposition in Examples 1 and 2 were deposited by mixing compounds 1 and 15 with mCBP, respectively, and in Comparative Examples 1 and 2, comparative compounds X-1 and X-2 were mixed with mCBP and deposited, respectively.

[0234] Subsequently, on the emitter layer, a layer with a thickness of [thickness value missing] is formed by TPBi. The layer is formed by LiQ with a thickness of A layer is formed to create an electron transport region. Then, a layer with a thickness of... The second electrode is formed of aluminum (Al). A CPL1 layer with a thickness of [missing information] is formed on the second electrode. The sealing layer.

[0235]

[0236] In this implementation, a vacuum deposition apparatus is used to form a hole transport region, an emitter layer, an electron transport region, and a second electrode.

[0237] Evaluation of the characteristics of organic electroluminescent devices

[0238] Table 3 shows the evaluation results of the organic electroluminescent devices of Examples 1 to 3 and Comparative Examples 1 and 2. Table 3 shows the maximum emission wavelength (λ) of the manufactured organic electroluminescent devices by comparison. max External quantum efficiency (EQE) max，1000尼特 In the characteristic evaluation results of the embodiments and comparative examples shown in Table 3, the maximum emission wavelength (λ) max The external quantum efficiency (EQE) refers to the wavelength representing the maximum value in the emission spectrum. max，1000尼特 (Refers to 1000 cd / m) 2 The efficiency obtained at the specified brightness.

[0239] Table 3

[0240] Example 1 Compound 1 460 8.2 Example 2 Compound 15 465 19.8 Example 3 Compound 21 463 17.5 Comparative Example 1 Compare compound X-1 466 5.3 Comparative Example 2 Compare compounds X-2 450 3.2

[0241] Referring to the results in Table 3, it can be seen that the organic electroluminescent devices of Examples 1 to 3 emit deep blue light with short wavelengths and exhibit high efficiency characteristics compared to the organic electroluminescent devices of Comparative Examples 1 and 2. In the case of the example compounds, reverse intersystem crossing (RISC) is more easily generated when compared with Comparative Compound X-1, and therefore the organic electroluminescent devices of Examples 1 to 3, which include the polycyclic compounds of the embodiments, have high external quantum efficiency.

[0242] The organic electroluminescent device in Comparative Example 2 emits short-wavelength light but has low external quantum efficiency.

[0243] Each of the example compounds comprises a phenyl group substituted with at least one cyano group as an electron-withdrawing group, and thus multiple resonances (e.g., resonance structures) can be delocalized in the polycyclic aromatic ring system. Because multiple resonances are delocalized in the example compounds, it can be seen that the organic electroluminescent device of Example 2 has an improved efficiency reduction at high brightness compared to the organic electroluminescent device of Comparative Example 1.

[0244] The polycyclic compounds of the embodiments include electron-withdrawing groups as substituents in 5- or 9-membered aromatic fused-ring systems containing nitrogen atoms and carbonyl groups as cyclic atoms, and thus multiple resonances are delocalized, and efficiency degradation at high brightness is improved. The polycyclic compounds of the embodiments can be included in the emitting layer of the organic electroluminescent device of the embodiments, thereby contributing to the improvement of efficiency degradation at high brightness.

[0245] The organic electroluminescent device of the embodiment exhibits improved high-efficiency device characteristics in the blue wavelength range.

[0246] The polycyclic compound of the embodiment may be included in the emitting layer of the organic electroluminescent device to help make the organic electroluminescent device highly efficient.

[0247] As used herein, the terms “substantially,” “about,” and similar terms are used as approximations rather than terms of degree and are intended to describe the inherent biases of measurements or calculations that will be recognized by one of ordinary skill in the art.

[0248] Any numerical range described herein is intended to include all subranges containing the same numerical precision within the described range. For example, the range “1.0 to 10.0” is intended to include all subranges between the described minimum value of 1.0 and the described maximum value of 10.0 (inclusive), i.e., subranges having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit described herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit described 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 describe any subranges contained within the range expressly described herein.

[0249] Although this disclosure has been described with reference to exemplary embodiments thereof, it will be understood that this disclosure should not be limited to these embodiments, but that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of this disclosure.

[0250] Therefore, the scope of this disclosure is not intended to be limited to what is set forth in the detailed description of the specification, but is intended to be defined by the appended claims and their equivalents.

Claims

1. An organic electroluminescent device, comprising: First electrode; The second electrode on the first electrode; and An emission layer consisting of a polycyclic compound represented by Formula 3 is included between the first electrode and the second electrode. The first electrode and the second electrode each independently comprise one selected from Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, In, Zn, Sn, and Yb, two or more of these compounds, mixtures of two or more of these compounds, or oxides thereof: Formula 3 ,and In Equation 3, Z1 and Z2 are each independently a cyano, a fluorine, an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine group, a phenyl group substituted with at least one cyano or at least one trifluoromethyl group, a substituted or unsubstituted pyridyl, a substituted or unsubstituted pyrimidinyl, or a substituted or unsubstituted triazine. b1 and b5 are each an independent integer selected from 1 to 4. b2 to b4 are each independently 1 or 2, and R1 to R5 are each independently a hydrogen atom, a deuterium atom, or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms.

2. The organic electroluminescent device as claimed in claim 1, wherein formula 3 is represented by formula 3-1: Equation 3-1 ,and In Equation 3-1, Y 11 To Y 16 Each is independently a nitrogen atom or CW 13 , g1 and g2 are each independently 1 or 2. W 11 To W 13 Each of the following groups is independently composed of a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms. b1, b3, b5, R1, R3, and R5 are each independently identical to those defined in Equation 3.

3. The organic electroluminescent device as claimed in claim 1, wherein Z1 and Z2 are each independently represented by any one of Z-1 to Z-13: ,and In Z-10 to Z-13, Ph is phenyl. This refers to the location to be connected.

4. The organic electroluminescent device as claimed in claim 1, wherein formula 3 is represented by formula 1-B: Formula 1-B ,and In Equation 1-B, Z a and Z b Each of the following is independently a cyano, a fluorine, an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine group, a phenyl group substituted with at least one cyano or at least one trifluoromethyl group, a substituted or unsubstituted pyridyl, a substituted or unsubstituted pyrimidinyl or a substituted or unsubstituted triazine.

5. The organic electroluminescent device of claim 1, wherein the emitting layer is used to emit delayed fluorescence.

6. The organic electroluminescent device of claim 1, wherein the emitting layer is used to emit light having a center wavelength of 430 nm to 470 nm.

7. The organic electroluminescent device of claim 1, wherein the emitting layer comprises at least one of the polycyclic compounds of group 1: Compound group 1 。

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