Organic electroluminescent devices and polycyclic compounds for organic electroluminescent devices

Abstract

To provide an organic electroluminescence device having a long life-time and high efficiency, and a polycyclic compound used therefor.SOLUTION: An organic electroluminescence device includes a first electrode, a hole transport layer on the first electrode, an emission layer on the hole transport layer, an electron transport layer on the emission layer, and a second electrode on the electron transport layer, wherein the emission layer includes a polycyclic compound represented by Formula 1, thereby exhibiting high emission efficiency. In Formula 1, at least one selected from Ring A and Ring B is a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms for forming a ring. Z is BAr2, POAr3, PSAr4, SiAr5Ar6, or GeAr7Ar8.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an organic electroluminescent device and a polycyclic compound used therein. [Background technology]

[0002] Recently, there has been a great deal of development activity in organic electroluminescence displays as image display devices. Unlike liquid crystal displays and the like, organic electroluminescence displays are so-called self-emissive display devices that achieve display by recombining holes and electrons injected from the first and second electrodes in the light-emitting layer, causing a light-emitting material containing an organic compound in the light-emitting layer to emit light.

[0003] When applying organic electroluminescent devices to display devices, there is a demand for lower driving voltage, higher luminous efficiency, and longer lifespan for these devices. Therefore, there is a continuous need for the development of organic electroluminescent device materials that can stably achieve these requirements.

[0004] In particular, in recent years, technologies have been developed for phosphorescence emission that utilizes the energy of the triplet state and for delayed fluorescence emission that utilizes the phenomenon of triplet exciton collisions generating singlet excitons (Triplet-triplet annihilation, TTA) in order to realize highly efficient organic electroluminescent devices. Development of thermally activated delayed fluorescence (TADF) materials that utilize the delayed fluorescence phenomenon is progressing. [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide a long-life, highly efficient organic electroluminescent element and a polycyclic compound used therein.

[0006] Another object of the present invention is to provide an organic electroluminescent element containing a thermally activated delayed fluorescence material and a polycyclic compound used as a thermally activated delayed fluorescence material. [Means for solving the problem]

[0007] According to one embodiment of the present invention, an organic electroluminescent device is provided, comprising a first electrode, a hole transport layer provided on the first electrode, a light-emitting layer provided on the hole transport layer, an electron transport layer provided on the light-emitting layer, and a second electrode provided on the electron transport layer, wherein the light-emitting layer comprises a polycyclic compound represented by the following chemical formula 1. [ka] In chemical formula 1, ring A and ring B are each independently substituted or unsubstituted aryl rings with 6 to 30 ring-forming carbon atoms, or substituted or unsubstituted heteroaryl rings with 2 to 30 ring-forming carbon atoms, and at least one of rings A and B is a substituted or unsubstituted heteroaryl ring with 2 to 30 ring-forming carbon atoms, and Z is BAr2, POAr 3. PSAr4, SiAr5Ar6, or GeAr7Ar8, where Ar1 is a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and Ar2 to Ar8 are each independently a substituted or unsubstituted amino group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted aralkyl group having 7 to 30 ring-forming carbon atoms, a substituted 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, and may bond with adjacent groups to form a ring.

[0008] At least one of rings A and B in chemical formula 1 is represented by the following chemical formula 2. [ka] In Chemical Formula 2, X and Y are each independently a single bond, O, S, SO, SO2, Se, NR3, PR4, POR5, PSR6, SiR7R8, GeR9R 10 , or BR 11 ; provided that X and Y are not simultaneously a single bond, and R1 to R 11 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted germyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thiol group, a substituted or unsubstituted amino group, a phosphine oxide group, a phosphine sulfide group, a silyl group, a carbonyl group, a boryl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming 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, and may combine with adjacent groups to form a ring.

[0009] The light-emitting layer is an organic electroluminescent device that emits delayed fluorescence.

[0010] The light-emitting layer is a delayed fluorescence-emitting layer containing a host and a dopant, and the dopant contains the polycyclic compound, which is an organic electroluminescent device.

[0011] The light-emitting layer is an organic electroluminescent device that is a thermally activated delayed fluorescence-emitting layer that emits blue light.

[0012] Chemical Formula 1 is represented by the following Chemical Formula 3.

Chemical Formula

[0013] In chemical formula 3, Z and Z' are the same.

[0014] Chemical formula 1 is represented by the following chemical formula 4. [ka] In chemical formula 4, W is B, PO, PS, SiAr5, or GeAr7; ring M is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms; Ar1' is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 carbon atoms; and rings A, B, Ar1, Ar5, and Ar7 are as defined in chemical formula 1.

[0015] In chemical formula 1, Z is BAr2.

[0016] In chemical formula 1, Z is represented by the following chemical formula 5. [ka] In chemical formula 5, V1 to V5 are each independently CR 12 or N, R 12 These are hydrogen atoms, deuterium atoms, halogen atoms, cyano groups, substituted or unsubstituted oxy groups, substituted or unsubstituted thiol groups, substituted or unsubstituted amino groups, phosphine oxide groups, phosphine sulfide groups, silyl groups, carbonyl groups, boryl groups, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted aralkyl groups having 7 to 30 ring-forming carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 ring-forming carbon atoms, and substituted or unsubstituted heteroaryl groups having 2 to 30 ring-forming carbon atoms, which may bond with adjacent groups to form a ring.

[0017] In Chemical Formula 5, V1 to V5 are each independently CR 12 where R[[ID=]5] 12 is a hydrogen atom, a deuterium atom, or a substituted or unsubstituted alkyl group having 2 to 10 carbon atoms.

[0018] At least one of Ring A and Ring B in Chemical Formula 1 is a substituted or unsubstituted pyrrole, a substituted or unsubstituted thiophene, a substituted or unsubstituted oxazine, or a substituted or unsubstituted furan. is a substituted or unsubstituted pyrrole, a substituted or unsubstituted thiophene, a substituted or unsubstituted oxazine, or a substituted or unsubstituted furan.

[0019] Chemical Formula 1 is represented by the following Chemical Formula 6. s

Chemical Formula

[0020] The polycyclic compound represented by chemical formula 1 is one of the compounds listed in the following Group 1 of compounds. [Compound group 1] [ka] JPEG0007841040000008.jpg210148 JPEG0007841040000009.jpg90151

[0021] According to one embodiment of the present invention, a polycyclic compound represented by chemical formula 1 is provided. [Brief explanation of the drawing]

[0022] [Figure 1] This is a schematic cross-sectional view showing an organic electroluminescent element according to one embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view showing an organic electroluminescent element according to one embodiment of the present invention. [Figure 3] This is a schematic cross-sectional view showing an organic electroluminescent element according to one embodiment of the present invention. [Modes for carrying out the invention]

[0023] Because the present invention can be modified in various ways and take on various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this should not be understood as limiting the present invention to any particular disclosure, but rather as including all modifications, equivalents, or substitutions that fall within the spirit and technical scope of the present invention.

[0024] In describing each drawing, similar reference numerals are used for similar components. In the attached drawings, the dimensions of the structures are shown enlarged to better illustrate the invention. Terms such as "first," "second," etc., are used to describe various components, but components are not limited to terms. Terms are used solely for the purpose of distinguishing one structural element from other components. For example, as long as it does not deviate from the scope of the invention, the first component may be called the second component, and similarly, the second component may be called the first component. A singular expression includes plural expressions unless the context clearly indicates otherwise.

[0025] In this application, terms such as “includes” or “having” indicate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood not to presuppose the existence or possibility of adding one or more other features, numbers, steps, actions, components, parts, or combinations thereof. Furthermore, when a part such as a layer, film, region, or plate is said to be “on” another part, this includes not only when it is “directly on” another part, but also when there is another part in between.

[0026] In this specification, -* indicates the position of joining.

[0027] In this specification, "substituted or unsubstituted" means substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium atoms, halogen atoms, cyano groups, nitro groups, amino groups, silyl groups, boryl groups, phosphine oxide groups, phosphine sulfide groups, gelmyl groups, alkyl groups, aryl groups, and heterocyclic groups. Furthermore, each of the exemplified substituents may be substituted or unsubstituted. For example, a biphenylyl group may be interpreted as an aryl group, or as a phenyl group substituted with a phenyl group.

[0028] In this specification, "forming a ring by bonding with adjacent groups" means forming a substituted or unsubstituted hydrocarbon ring, or a substituted or unsubstituted heterocycle, by bonding with adjacent groups to each other. Hydrocarbon rings include aliphatic hydrocarbon rings and aromatic hydrocarbon rings. Heterocycles include aliphatic heterocycles and aromatic heterocycles. Hydrocarbon rings and heterocycles can be monocyclic or polycyclic. Furthermore, rings formed by bonding with adjacent groups may be linked with other rings to form a spirostructure.

[0029] In this specification, "adjacent group" means a substituent substituted on an atom directly bonded to the atom to which the substituent is substituted, another substituent substituted on the atom to which the substituent is substituted, or the substituent that is most stereostructically adjacent to the substituent in question. For example, the two methyl groups in 1,2-dimethylbenzene are interpreted as "adjacent groups," and the two ethyl groups in 1,1-diethylcyclopentene are interpreted as "adjacent groups."

[0030] In this specification, examples of halogen atoms include fluorine, chlorine, bromine, or iodine atoms.

[0031] In this specification, alkyl groups are linear, branched, or cyclic. The number of carbon atoms in an alkyl group is 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl, i-butyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, i-pentyl, neopentyl, t-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, and 2-ethyl Hexyl group, 2-butylhexyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-t-butylcyclohexyl group, n-heptyl group, 1-methylpeptyl group, 2,2-dimethylheptyl group, 2-ethylheptyl group, 2-butylheptyl group, n-octyl group, t-octyl group, 2-ethyloctyl group, 2-butyloctyl group, 2-hexyloctyl group, 3,7-dimethyloctyl group, cyclooctyl group, n-nonyl group, n-decyl group, Adamantine Ntyl group, 2-ethyldecyl group, 2-butyldecyl group, 2-hexyldecyl group, 2-octyldecyl group, n-undecyl group, n-dodecyl group, 2-ethyldodecyl group, 2-butyldodecyl group, 2-hexyldodecyl group, 2-octyldecyl group, n-tridecyl group, n-tetradecyl group, n-pentadecyl group, n-hexadecyl group, 2-ethylhexadecyl group, 2-butylhexadecyl group, 2-hexylhexadecyl group, 2-octylhexadecyl group Examples include, but are not limited to, n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-icosyl group, 2-ethylicosyl group, 2-butylicosyl group, 2-hexylicosyl group, 2-octylicosyl group, n-henicosyl group, n-docosyl group, n-tricosyl group, n-tetracosyl group, n-pentacosyl group, n-hexacosyl group, n-heptacosyl group, n-octacosyl group, n-nonacosyl group, and n-triacontyl group.

[0032] In this specification, an aryl group means any active group or substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of ring-forming carbon atoms in a reel group is 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, fluorenyl, anthracenyl, phenanthryl, biphenylyl, terphenylyl, quarterphenylyl, quinkphenylyl, sexiphenylyl, triphenylenyl, pyrenyl, benzofluoranteyl, and crisenyl groups.

[0033] In this specification, the fluorenyl group may be substituted, and two substituents may bond to each other to form a spiro structure. Examples of substitutions of the fluorenyl group are, but are not limited to, the following. [ka]

[0034] In this specification, a heteroaryl group is a heteroaryl group containing one or more heteroatoms from O, N, P, Si, and S. The number of ring-forming carbon atoms in the heteroaryl group is 2 to 30, or 2 to 20. The heteroaryl group is a monocyclic heteroaryl group or a polycyclic heteroaryl group. A polycyclic heteroaryl group may have, for example, a bicyclic or tricyclic structure. Examples of heteroaryl groups include thiophenyl group, furanyl group, pyrrolyl group, imidazolyl group, thiazolyl group, oxazolyl group, oxadiazolyl group, triazolyl group, pyridyl group, bipyridyl group, pyrimidyl group, triazinyl group, triazolyl group, acridinyl group, pyridadinyl group, quinolinyl group, quinazolyl group, quinoxalinyl group, phenoxazinyl group, phthalazinyl group, pyridopyrimidinyl group, pyridopyradinyl group, pyrazinopyradinyl group, isoquinolinyl group, indolyl group, carbazolyl group, and N-allyl group. Examples of such groups include, but are not limited to, carbazolyl groups, N-heteroallylcarbazolyl groups, N-alkylcarbazolyl groups, benzoxazolyl groups, benzimidazolyl groups, benzothiazolyl groups, benzocarbazolyl groups, benzothiophenyl groups, dibenzothiophenyl groups, thienothiophenyl groups, benzofuranyl groups, phenanthrolinyl groups, thiazolyl groups, isoxazolyl groups, oxadiazolyl groups, thiadiazolyl groups, benzothiazolyl groups, phenothiazinyl groups, dibenzosilolyl groups, and dibenzofuranyl groups.

[0035] In this specification, the silyl group includes alkylsilyl groups and arylsilyl groups. Examples of silyl groups include, but are not limited to, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, and phenylsilyl groups.

[0036] In this specification, the number of carbon atoms in the amino group is not particularly limited, but may be between 1 and 30. The amino group includes alkylamino groups and arylamino groups. Examples of amino groups include, but are not limited to, methylamino groups, dimethylamino groups, phenylamino groups, naphthylamino groups, 9-methyl-anthracenylamino groups, and triphenylamino groups.

[0037] In this specification, the phosphine oxide group is, for example, a small number of alkyl and aryl groups. The phosphine oxide group may be substituted with at least one of the alkyl and aryl groups, for example. Examples of phosphine oxide groups include, but are not limited to, the phenylphosphine oxide group and the diphenylphosphine oxide group.

[0038] In this specification, the boryl group may be substituted with, for example, at least one of an alkyl group and an aryl group. Examples of boryl groups include, but are not limited to, phenylboryl and diphenylboryl groups.

[0039] In this specification, the gelmyl group may be substituted with, for example, at least one of an alkyl group and an aryl group. Examples of gelmyl groups include, but are not limited to, the phenylgelmyl group and the diphenylgelmyl group.

[0040] The following describes an organic electroluminescent element according to one embodiment of the present invention, with reference to Figures 1 to 3.

[0041] Referring to Figures 1 to 3, the organic electroluminescent element 10 according to one embodiment of the present invention includes a first electrode EL1, a hole transport region HTR, a light-emitting layer EML, an electron transport region ETR, and a second electrode EL2, which are sequentially stacked.

[0042] The first electrode EL1 and the second electrode EL2 are arranged facing each other, and a plurality of organic layers are arranged between the first electrode EL1 and the second electrode EL2. The plurality of organic layers include a hole transport region HTR, an emissive layer EML, and an electron transport region ETR. In one embodiment, the organic electroluminescent element 10 contains a polycyclic compound according to one embodiment in the emissive layer EML.

[0043] On the other hand, Figure 2 shows a cross-sectional view of an organic electroluminescent element 10 in one embodiment, in comparison to Figure 1, in which 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, Figure 3 shows a cross-sectional view of an organic electroluminescent element 10 in one embodiment, in which 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, in comparison to Figure 1.

[0044] In an organic electroluminescent element 10 according to one embodiment, the first electrode EL1 is conductive. The first electrode EL1 is made of a metal alloy or a conductive compound. The first electrode EL1 is the anode.

[0045] The first electrode EL1 is a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. If the first electrode EL1 is a transmissive electrode, it consists of a transparent metal oxide, such as ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), ITZO (indium tin zinc oxide), etc. If the first electrode EL1 is a semi-transmissive or reflective electrode, it contains Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or compounds or mixtures thereof (e.g., an alloy of Ag and Mg). It may also have a multi-layer structure including a reflective or semi-transmissive film formed from the exemplified materials, and a transparent conductive film formed from ITO, IZO, ZnO, ITZO, etc. For example, the first electrode EL1 may contain multiple layers of ITO / Ag / ITO.

[0046] The hole transport region HTR is provided on the first electrode EL1. The hole transport region HTR includes at least one of the following: a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer, and an electron blocking layer EBL.

[0047] The hole transport region (HTR) has a multilayer structure consisting of a single layer made of a single material, a single layer made of multiple different materials, or multiple layers made of multiple different materials.

[0048] 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 structure formed of a hole injection material and a hole transport material. Furthermore, the hole transport region HTR may have a single-layer structure of multiple different materials, or it may have a structure of a hole injection layer HIL / hole transport layer HTL, a hole injection layer HIL / hole transport layer HTL / hole buffer layer, a hole injection layer HIL / hole buffer layer, a hole transport layer HTL / hole buffer layer, or a hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL stacked in order from the first electrode EL1, but is not limited to these.

[0049] Hole transport regions (HTRs) are formed using a variety of methods, including vacuum deposition, spin coating, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and laser-induced thermal imaging (LITI).

[0050] The hole injection layer HIL of the organic electroluminescent element 10 according to one embodiment includes known hole injection materials. For example, the hole injection layer HIL includes triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(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, It may also contain, but is not limited to, 4',4"-tris{N,N-diphenylamino}triphenylamine (TDATA), 4,4',4"-tris(N,N-2-naphthylphenylamino)triphenylamine (2-TNATA), polyaniline / dodecylbenzenesulfonic acid (PANI / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (PANI / CSA), polyaniline / poly(4-styrenesulfonate) (PANI / PSS), or HAT-CN (dipyradino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitride), etc.

[0051] The hole transport layer (HTL) of the organic electroluminescent element 10 according to one embodiment includes a known hole transport material. For example, the hole transport layer HTL may include 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD), 4,4',4”-tris(N-carbazol)triphenylamine (TCTA), or N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (NPB), N,N'-bis(1-naphthyl)-N,N'-diphenyl-4,4'-diamine (α-NPD), etc. However, it is not limited to these.

[0052] On the other hand, the hole transport region (HTR) may further include an electron blocking layer (EBL). The electron blocking layer (EBL) is positioned between the hole transport layer (HTL) and the light-emitting layer (EML). The electron blocking layer (EBL) is a layer that prevents electrons from being injected from the electron transport region (ETR) into the hole transport region (HTR).

[0053] The electron blocking layer (EBL) includes common materials known in the relevant art. The electron blocking layer (EBL) may include, for example, carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, fluorene derivatives, triphenylamine derivatives such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine) and TCTA (4,4',4"-tris(N-carbazolyl)triphenylamine), NPB (N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine), TAPC (4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzeneamine]), HMTPD (4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), or mCP. Furthermore, as described above, the hole blocking layer (EBL) may also include a polycyclic compound according to one embodiment of the present invention.

[0054] The thickness of the hole transport region (HTR) may be approximately 10 nm to 1000 nm, for example, approximately 10 nm to 500 nm. The thickness of the hole injection layer (HIL) may be approximately 3 nm to 100 nm, and the thickness of the hole transport layer (HTL) may be approximately 3 nm to 100 nm. For example, the thickness of the electron blocking layer (EBL) may be approximately 1 nm to 100 nm. 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-described ranges, sufficient hole transport characteristics can be obtained without a substantial increase in the driving voltage.

[0055] The hole transport region (HTR) may further contain charge-generating materials in addition to the materials described above to improve conductivity. The charge-generating materials are uniformly or non-uniformly dispersed within the hole transport region (HTR). The charge-generating materials are, for example, p-dopant. The p-dopant may be, but is not limited to, a quinone derivative, a metal oxide, or a cyano group-containing compound. For example, non-restrictive examples of p-dopant include, but are not limited to, quinone derivatives such as TCNQ (tetracyanoquinodimethane) and F4-TCNQ (2,3,5,6-tetrafluoro-tetracyanoquinodimethane), metal oxides such as tungsten oxide and molybdenum oxide.

[0056] As described above, the hole transport region (HTR) may further include at least one of a hole buffer layer and an electron blocking layer (EBL) in addition to the hole injection layer (HIL) and the hole transport layer (HTL). The hole buffer layer compensates for the resonance distance due to the wavelength of light emitted from the light emission layer (EML) and increases the light emission efficiency. The material included in the hole buffer layer is a material that can be included in the hole transport region (HTR).

[0057] The light-emitting layer (EML) is provided on top of the hole transport region (HTR). The thickness of the light-emitting layer (EML) may be, for example, 10 nm to 60 nm. The light-emitting layer (EML) has a multilayer structure consisting of a single layer made of a single material, a single layer made of multiple different materials, or multiple layers made of multiple different materials.

[0058] The EML (Emitting-Emitting Layer) emits one of the following colors: red, green, blue, white, yellow, or cyan. The EML contains a fluorescent or phosphorescent material.

[0059] In one embodiment, the light-emitting layer EML is a fluorescent light-emitting layer. For example, a portion of the light emitted from the light-emitting layer EML is thermally activated delayed fluorescence (FFL). This may also be due to Delayed Fluorescence (TADF). More specifically, the EML luminescent layer contains a thermally activated delayed fluorescence luminescent component, and in one real form, the EML luminescent layer is a thermally activated delayed fluorescence luminescent layer that emits blue light.

[0060] In one embodiment, the luminescent layer EML contains a polycyclic compound represented by chemical formula 1. [ka]

[0061] In chemical formula 1, ring A and ring B are independently substituted or unsubstituted aryl rings with 6 to 30 ring-forming carbon atoms, or substituted or unsubstituted heteroaryl rings with 2 to 30 ring-forming carbon atoms.

[0062] On the other hand, in chemical formula 1, at least one of rings A and B is a substituted or unsubstituted heteroaryl ring with 2 to 30 ring-forming carbon atoms. If neither ring A nor ring B is a heteroaryl ring, the molecular stability will be low, which may reduce the luminous efficiency or lifetime when applied to organic electroluminescent devices.

[0063] In chemical formula 1, Z is BAr2, POAr3, PSAr4, SiAr5Ar6, or GeAr7Ar8.

[0064] In chemical formula 1, Ar1 is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.

[0065] In chemical formula 1, Ar2 to Ar8 are each independently a substituted or unsubstituted amino group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and may bond with adjacent groups to form a ring.

[0066] In one embodiment, at least one of rings A and B of chemical formula 1 is represented by the following chemical formula 2. [ka]

[0067] In chemical formula 2, X and Y are independently single bonds, O, S, SO, SO2, Se, NR3, PR4, POR5, PSR6, SiR7R8, GeR9R 10 , or BR 11 That is the case.

[0068] In chemical formula 2, R1~R 11 Each of these independently consists of a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted gelmyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thiol group, a substituted or unsubstituted amino group, a phosphine oxide group, a phosphine sulfide group, a silyl group, a carbonyl group, These are boryl groups, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, substituted or unsubstituted aralkyl groups having 7 to 30 ring-forming carbon atoms, substituted or unsubstituted aryl groups having 6 to 30 ring-forming carbon atoms, and substituted or unsubstituted heteroaryl groups having 2 to 30 ring-forming carbon atoms. R1~R 11 It may bond with an adjacent group to form a ring.

[0069] In chemical formula 1, either ring A or ring B is a heteroaryl ring, and X and Y in chemical formula 2 cannot be single bonds at the same time.

[0070] In one embodiment, Ar1 in chemical formula 1 is 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, and may bond with adjacent groups to form a ring.

[0071] In one embodiment, if Ar1 in chemical formula 1 has a substituent, and this substituent bonds to one of the ring-forming atoms of ring B in chemical formula 1 to form a fused ring, then chemical formula 1 may also be represented by the following chemical formula 3. [ka]

[0072] In chemical formula 3, Z' corresponds to one of the substituents of Ar1 in chemical formula 1. Z' is either BAr2, POAr3, PSAr4, SiAr5Ar6, or GeAr7Ar8.

[0073] In chemical formula 3, ring L corresponds to Ar1 in chemical formula 1. Each ring L is independently 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.

[0074] In chemical formula 3, rings A, B, and Z are defined as in chemical formula 1.

[0075] In one embodiment, Z and Z' in chemical formula 3 may be the same as each other.

[0076] In chemical formula 1, Ar2 to Ar8 are each independently a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and may bond with adjacent groups to form a ring.

[0077] In one embodiment, if any of Ar2, Ar3, Ar4, Ar5, and Ar6, or any of Ar7 and Ar8, in chemical formula 1 is substituted with an amino group having Ar1' as a substituent, and the amino group is bonded to one of the ring-forming atoms of ring B in chemical formula 1 to form a fused ring, then chemical formula 1 may be represented by the following chemical formula 4. [ka]

[0078] In chemical formula 4, W corresponds to Z in chemical formula 1, where the ring M is substituted. W is B, PO, PS, SiAr5, or GeAr7.

[0079] In chemical formula 4, ring M is Ar2, Ar3, Ar4, Ar6, or Ar8, each independently being a substituted or unsubstituted aryl group with 6 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group with 2 to 30 ring-forming carbon atoms.

[0080] In chemical formula 4, Ar1' is a substituent of an amino group substituted on ring M, where Ar1' is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.

[0081] In chemical formula 4, rings A, B, Ar1, Ar5, and Ar7 are defined as in chemical formula 1.

[0082] In one embodiment, Z in chemical formula 1 is BAr2.

[0083] If Z in chemical formula 1 is BAr2, then Z may also be represented by the following chemical formula 5. [ka]

[0084] In chemical formula 5, V1 to V5 are each independently CR 12 Or it is N. On the other hand, at least one of V1 to V5 is CR 12 That is the case.

[0085] In chemical formula 5, R 12 Each of these groups is independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thiol group, a substituted or unsubstituted amino group, a phosphine oxide group, a phosphine sulfide group, a silyl group, a carbonyl group, a boryl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming 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, and may bond with adjacent groups to form a ring.

[0086] In one embodiment, V1 to V5 of chemical formula 5 are each independently CR 12 And R 12 This is a hydrogen atom, a deuterium atom, or a substituted or unsubstituted alkyl group having 2 to 10 carbon atoms.

[0087] In one embodiment, at least one of rings A and B of chemical formula 1 is a substituted or unsubstituted pyrrole, a substituted or unsubstituted thiophene, a substituted or unsubstituted oxazine, or a substituted or unsubstituted furan.

[0088] In one embodiment, chemical formula 1 is represented by the following chemical formula 6. [ka]

[0089] In chemical formula 6, A1 is a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thiol group, a substituted or unsubstituted amino group, a phosphine oxide group, a phosphine sulfide group, a silyl group, a carbonyl group, a boryl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming 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, which may bond with adjacent groups to form a ring.

[0090] In chemical formula 6, n is an integer between 0 and 5 (inclusive). On the other hand, if n is 2 or greater, multiple A1 molecules may be the same or different from one another.

[0091] In chemical formula 6, X and Y are independently single bonds, O, S, SO, SO2, Se, NR3, PR4, POR5, PSR6, SiR7R8, GeR9R 10 , or BR 11 That is the case.

[0092] In chemical formula 6, R1 to R 11 Each of these is independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thiol group, a substituted or unsubstituted amino group, a phosphine oxide group, a phosphine sulfide group, a silyl group, a carbonyl group, a boryl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming 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. R1~R 11It may bond with an adjacent group to form a ring.

[0093] In chemical formula 6, Ar1 is defined as in chemical formula 1.

[0094] The polycyclic compound represented by chemical formula 1 according to one embodiment is a delayed fluorescence material. This polycyclic compound is a thermally activated delayed fluorescence material.

[0095] For example, the polycyclic compound represented by chemical formula 1 has a small difference between the singlet energy level S1 and the triplet energy level T1 and may be used as a thermally activated delayed fluorescence material. Specifically, the polycyclic compound represented by chemical formula 1 according to one embodiment may be represented by any one of the compounds shown in the following first compound group. In the following compound group 1, iPr represents an isopropyl group and Ph represents a phenyl group.

[0096] [First compound group] [ka] JPEG0007841040000018.jpg194149 JPEG0007841040000019.jpg90151

[0097] The polycyclic compound represented by chemical formula 1 described above is used in an organic electroluminescent element 10 according to one embodiment to improve the efficiency and lifespan of the organic electroluminescent element. More specifically, the polycyclic compound represented by chemical formula 1 described above is used in the light-emitting layer EML of the organic electroluminescent element 10 according to one embodiment to improve the luminous efficiency and lifespan of the organic electroluminescent element.

[0098] In one embodiment, the light-emitting layer EML comprises a host and a dopant, the host being a delayed fluorescence host and the dopant being a delayed fluorescence dopant. On the other hand, the polycyclic compound represented by chemical formula 1 according to one embodiment is included as a dopant material in the light-emitting layer EML. For example, the polycyclic compound represented by chemical formula 1 according to one embodiment may be used as a TADF dopant.

[0099] On the other hand, the luminescent layer EML contains a known host material. For example, in one embodiment, the luminescent layer EML is a host material of Alq3 (tris(8-hydroxyquinolino)aluminum), CBP (4,4'-bis(N-carbazol)-1,1'-biphenyl), PVK (poly(n-vinylcarbazole), ADN (9,10-di(naphthalene-2-yl)anthracene), TCTA (4,4',4”-tris(carbazole-9-yl)triphenylamine), TPBi (1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene), TBADN (3-tert-butyl-9,10-di(naphtho-2-yl)anthracene), DSA (distyrylallylen), CDBP (4,4'-bis(9- The host materials may include, for example, rubazolyl)-2,2'-dimethyl-biphenyl), MADN (2-methyl-9,10-bis(naphthalene-2-yl)anthracene), DPEPO (bis[2-(diphenylphosphino)phenyl]ether oxide), CP1 (hexaphenylcyclotriphosphazene), UGH2 (1,4-bis(triphenylsilyl)benzene), DPSiO3 (hexaphenylcyclotrisiloxane), DPSiO4 (octaphenylcyclotetrasiloxane), or PPF (2,8-bis(diphenylphospholyl)dizenzofuran). However, the host materials are not limited to these, and other known delayed-emission host materials may also be included.

[0100] On the other hand, in an organic electroluminescent element 10 according to one embodiment, the light-emitting layer EML may further contain known dopant materials. The light-emitting layer MEL may contain a styryl derivative (for example, 1,4-bis[2-(3-N-ethylcarbazol)vinyl]benzene (BCzV) as a dopant. B) includes 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styryl]stilbene (DPAVB), N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzeneamine (N-BDAVBi), perylene and its derivatives (e.g., 2,5,8,11-tetra-t-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1-dipylene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene), etc.

[0101] Referring further to Figures 1 to 3, in an organic electroluminescent element 10 according to one embodiment, the electron transport region (ETR) is provided on the light-emitting layer (EML). The electron transport region (ETR) includes, but is not limited to, an electron blocking layer, an electron transport layer (ETL), and an electron injection layer (EIL).

[0102] The electron transport region (ETR) has a multilayer structure consisting of a single layer made of a single material, a single layer made of multiple different materials, or multiple layers made of multiple different materials.

[0103] For example, the electron transport region (ETR) may have a single-layer structure consisting of an electron injection layer (EIL) or electron transport layer (ETL), or a single-layer structure consisting of an electron injection material and an electron transport material. Furthermore, the electron transport region (ETR) may have a single-layer structure consisting of multiple different materials, or it may have a structure of electron transport layer (ETL) / electron injection layer (EIL), hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL), etc., stacked sequentially from the first electrode (EL1), but is not limited to these. The thickness of the electron transport region (ETR) may be, for example, about 10 nm to about 150 nm.

[0104] The electron transport region (ETR) is formed using a variety of methods, including vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and laser-induced thermal imaging (LITI).

[0105] If the electron transport region ETR includes the electron transport layer ETL, for example, the electron transport region ETR may be Alq3(tris(8-hydroxyquinolinato)aluminum), 1,3,5-tri[(3-pyridyl)phen-3-yl]benzene, 2,4,6-tris(3'-pyridine-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzimidazolyl-1-ylphenyl)-9,10-dinaphthylanthracene, TPBi(1,3,5-tri(1-phenyl-1H-benzo[d]imidazole-2-yl)benzene), BCP(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen(4,7-diphenyl-1,10-phenanthroline) It may also contain, but is not limited to, nanthroline, TAZ (3-(4-biphenylyl)-4-phenyl-5-terto-butylphenyl-1,2,4-triazole), NTAZ (4-(naphthalene-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD (2-(4-biphenylyl)-5-(4-terto-butylphenyl)-1,3,4-oxadiazole), BAlq (bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-orato)aluminum), Bebq2 (beryllium bis(benzoquinoline-10-orato), ADN (9,10-di(naphthalene-2-yl)anthracene), and mixtures thereof.

[0106] If the electron transport region (ETR) includes an electron transport layer (ETL), the thickness of the electron transport layer (ETL) may be approximately 10 nm to 100 nm, for example, approximately 15 nm to 50 nm. When the thickness of the electron transport layer (HTL) satisfies the above-mentioned range, sufficient electron transport characteristics can be obtained without a substantial increase in the driving voltage.

[0107] If the electron transport region (ETR) includes an electron injection layer (EIL), the ETR may, but is not limited to, lanthanum group metals such as LiF, LiQ (lithium quinolinate), Li2O, BaO, NaCl, CsF, and Yb, or metal halides such as RbCl, RbI, and KI. The electron injection layer (EIL) also consists of a mixture of the electron transport material and an insulating organometallic salt. Metallic salts have an energy band gap of approximately 4 eV. These are the substances mentioned above. More specifically, organometallic salts include, for example, metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate, or metal stearate.

[0108] When the electron transport region (ETR) includes an electron injection layer (ETL), the thickness of the electron injection layer (ETL) is approximately 0.1 nm to 10 nm or approximately 0.3 nm to 9 nm. If the thickness of the electron injection layer (EIL) satisfies the above range, sufficient electron injection characteristics can be obtained without a substantial increase in the driving voltage.

[0109] The electron transport region (ETR) includes a hole blocking layer (HBL), as described above. The hole blocking layer (HBL) may include, but is not limited to, at least one of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and Bphen (4,7-diphenyl-1,10-phenanthroline).

[0110] The second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 is conductive. The second electrode EL2 is made of a metal alloy or a conductive compound. The second electrode layer EL2 is a cathode. The second electrode EL2 can be a transmissive electrode, a semi-transmissive electrode, or This is a reflective electrode. If the second electrode EL2 is a transmissive electrode, then the second electrode EL2 is made of a transparent metal oxide, such as ITO, IZO, ZnO, ITZO, etc.

[0111] If the second electrode EL2 is a semi-transparent or reflective electrode, the second electrode EL2 includes Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or compounds or mixtures thereof (for example, a mixture of Ag and Mg). Alternatively, it may be a multi-layer structure including a reflective film or semi-transparent film formed from the exemplified materials, and a transparent conductive film formed from ITO, IZO, ZnO, ITZO, etc.

[0112] Although not shown in the diagram, the second electrode EL2 is connected to an auxiliary electrode. When the second electrode EL2 is connected to an auxiliary electrode, the resistance of the second electrode EL2 can be reduced.

[0113] In the organic electrolytic light-emitting element 10, when a voltage is applied to the first electrode EL1 and the second electrode EL2, the holes injected from the first electrode EL1 are transported to the hole transport region HTR. Electrons injected from the second electrode EL2 move to the emissive layer EML via the electron transport region ETR. Electrons and holes recombine in the emissive layer EML to produce an exciton, which emits light when it falls from the excited state to the ground state.

[0114] If the organic electroluminescent element 10 is a front-emitting type, the first electrode EL1 is a reflective electrode, and the second electrode EL2 is a transmissive or semi-transmissive electrode. If the organic electroluminescent element 10 is a back-emitting type, the first electrode EL1 is a transmissive or semi-transmissive electrode, and the second electrode EL2 is a reflective electrode.

[0115] An organic electroluminescent element 10 according to one embodiment of the present invention uses the above-mentioned polycyclic compound as the light-emitting layer material. When used in this manner, it exhibits improved luminous efficiency and lifespan characteristics.

[0116] According to one embodiment of the present invention, a polycyclic compound represented by the following chemical formula 1 is provided. [ka]

[0117] In chemical formula 1, ring A and ring B are independently substituted or unsubstituted aryl rings with 6 to 30 ring-forming carbon atoms, or substituted or unsubstituted heteroaryl rings with 2 to 30 ring-forming carbon atoms.

[0118] On the other hand, in chemical formula 1, at least one of rings A and B is a substituted or unsubstituted heteroaryl ring with 2 to 30 ring-forming carbon atoms. If neither ring A nor ring B is a heteroaryl ring, the molecular stability will be low, which may reduce the luminous efficiency or lifetime when applied to organic electroluminescent devices.

[0119] In chemical formula 1, Z is BAr2, POAr3, PSAr4, SiAr5Ar6, or GeAr7Ar8.

[0120] In chemical formula 1, Ar1 is a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms.

[0121] In chemical formula 1, Ar2 to Ar8 are each independently a substituted or unsubstituted amino group, a substituted or unsubstituted oxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms, and may bond with adjacent groups to form a ring.

[0122] In one embodiment, at least one of rings A and B of chemical formula 1 is represented by the following chemical formula 2. [ka]

[0123] In the chemical formula 2 below, X and Y are independently single bonds, O, S, SO, SO2, Se, NR3, PR4, POR5, PSR6, SiR7R8, GeR9R 10 , or BR 11 That is the case.

[0124] In chemical formula 2, R1 to R2 are independently a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thiol group, a substituted or unsubstituted amino group, a phosphine oxide group, a phosphine sulfide group, a silyl group, and a carbonyl group. These are a r group, a boryl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 ring-forming carbon atoms, and a substituted or unsubstituted heteroaryl group having 2 to 30 ring-forming carbon atoms. R3~R 11 Each of these is independently a hydrogen atom, a deuterium atom, a halogen atom, a cyano group, a substituted or unsubstituted oxy group, a substituted or unsubstituted thiol group, a substituted or unsubstituted amino group, a phosphine oxide group, a phosphine sulfide group, a silyl group, a carbonyl group, a boryl group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring-forming 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. R1~R 11 It may bond with an adjacent group to form a ring.

[0125] In chemical formula 1, either ring A or ring B is a heteroaryl ring, and X and Y in chemical formula 2 cannot be single bonds at the same time.

[0126] The same description of polycyclic compounds described above in the organic electroluminescent device according to one embodiment applies to the polycyclic compound represented by chemical formula 1.

[0127] The polycyclic compound according to one embodiment is one selected from the compounds shown in the first group of compounds described above. [Examples]

[0128] The present invention will be described in more detail below through specific examples and comparative examples. The following examples are merely illustrative to aid in understanding the present invention, and the scope of the invention is not limited thereto.

[0129] (Example of combination) A polycyclic compound according to one embodiment of the present invention can be synthesized, for example, as described below. However, the method for synthesizing a polycyclic compound according to one embodiment of the present invention is not limited to the following.

[0130] 1. Synthesis of Compound 8 Compound 8, which is a polycyclic compound according to one embodiment of the present invention, can be synthesized, for example, by the following reaction. [ka]

[0131] (Synthesis of intermediate compound A) Under an Ar atmosphere, N into a 300 mL three-necked flask. 1 -(2,3-dichlorophenyl)-N 1 ,N 2 ,N 3 9.63 g (20 mmol) of triphenyl-1,3-benzenediamine, 2.0 mL (22 mmol) of aniline, 0.71 g (1.0 mmol) of (Amphos)PdCl2, and 2.11 g (22 mmol) of NaOtBu were added and stirred in 100 mL of xylene solvent at 120°C for 1 hour. After cooling in air, water was added to separate the organic layer, and the solvent was removed by rinsing. The resulting crude product was purified by column chromatography (silica gel) to obtain 7.40 g (69% yield) of compound A as a white solid. The compound was measured by FAB-MS. The molecular weight of compound A was 537.

[0132] (Synthesis of intermediate compound B) Under an Ar atmosphere, 7.37 g (13.7 mol) of compound A, 4.08 g (15.0 mmol) of 2-bromo-1-phenyl-1H-indole, 0.13 g (0.14 mmol) of Pd2(dba)3, 0.26 g (0.55 mmol) of Ruphos (2-dicyclohexylphosphino-2',6'-diisopropoxybiphenyl), and 1.44 g (15.0 mmol) of NaOtBu were added to a 200 mL three-necked flask and stirred at 100 °C for 3 hours in 70 mL of toluene. After cooling in air, water was added to separate the organic layer, and the solvent was removed. The resulting crude product was purified by column chromatography (silica gel) to obtain 6.79 g (yield 68%) of compound B as a white solid. The molecular weight of compound B, as measured by FAB-MS, was 728.

[0133] (Synthesis of Compound 8) Under an Ar atmosphere, 50 mL of a 6.78 g (9.3 mmol) solution of compound B in anhydrous t-butylbenzene was added to a 300 mL three-necked flask and stirred at -78°C. 19.5 mL (37 mmol) of a 1.9 M t-BuLi pentane solution was added dropwise. After the addition was complete, the temperature was raised to 60°C and stirred for 2 hours, then components with a lower boiling point than t-butylbenzene were removed under reduced pressure. The mixture was cooled to -30°C, and 1.8 mL (19 mmol) of BBr3 was added dropwise. After the addition was complete, the temperature was raised to room temperature and stirred for 2 hours. Then, the mixture was further cooled to 0°C, and 1.7 mL (9.8 mmol) of N,N-diisopropylethylamine was added dropwise. After the addition was complete, the temperature was raised to room temperature and stirred for 1 hour, then the temperature was raised to 120°C and heated and stirred for 8 hours. The reaction mixture was cooled to room temperature, and then separated by adding an aqueous NaOAc solution cooled in an ice bath and toluene. Next, the mixture was purified by short column chromatography (silica gel), and then recrystallized in toluene / hexane solvent to obtain 5.09 g of compound 8 as a yellow solid (yield 78%).

[0134] Compound 8 was identified by FAB-MS and NMR. The molecular weight of compound 8, as measured by FAB-MS, was 702. 1 H-NMR (CDCl3) measurement The measured chemical shift values ​​δ for compound 8 were 8.43 (1H), 7.94 (1H), 7.69-7.48 (6H), 7.37-7.22 (11H), 7.10-6.98 (12H), and 6.86-6.81 (4H).

[0135] 2. Synthesis of Compound 10 Compound 10, which is a polycyclic compound according to one embodiment of the present invention, can be synthesized, for example, by the following reaction. [ka]

[0136] (Synthesis of intermediate compound C) Under an Ar atmosphere, 6.28 g (20 mmol) of 2,3-dichloro-N,N-diphenyl-1,3-benzenediamine and 2.0 mL (2 mmol) of aniline were added to a 300 mL three-necked flask. 2 mmol) of (Amphos)PdCl2, 0.71 g (1.0 mmol), and 2.11 g (22 mmol) of NaOtBu were added, and the mixture was stirred in 100 mL of xylene solvent at 120°C for 1 hour. After cooling in air, water was added to separate the organic layer, and the solvent was removed. The resulting crude product was purified by column chromatography (silica gel) to obtain 6.00 g (81% yield) of compound C as a white solid. The molecular weight of compound C, as measured by FAB-MS, was 370.

[0137] (Synthesis of intermediate compound D) Under an Ar atmosphere, 5.97 g (16.1 mol) of compound C and 4.38 g (17.7 mmol) of 3-bromo-6-chlorobenzo[b]thiophene were added to a 200 mL three-necked flask. 0.15 g (0.16 mmol) of Pd2(dba)3, 0.30 g (0.64 mmol) of Ruphos, and 1.70 g (17.7 mmol) of NaOtBu were added, and the mixture was stirred in 80 mL of toluene at 100°C for 3 hours. After cooling in air, water was added to separate the organic layer, and the solvent was removed. The resulting crude product was purified by column chromatography (silica gel) to obtain 5.27 g (61% yield) of compound D as a white solid. The molecular weight of compound D, as measured by FAB-MS, was 536.

[0138] (Synthesis of intermediate compound E) Under an Ar atmosphere, 5.26 g (9.8 mol) of compound D, 1.66 g (9.8 mmol) of diphenylamine, 0.18 g (0.20 mmol) of Pd2(dba)3, 0.36 g (0.78 mmol) of Ruphos, and 1.04 g (10.8 mmol) of NaOtBu were added to a 200 mL three-necked flask and stirred at 110 °C for 8 hours in 50 mL of toluene. After cooling in air, water was added to separate the organic layer, and the solvent was removed. The resulting crude product was purified by column chromatography (silica gel) to obtain 5.05 g (yield 777%) of compound E as a white solid. The molecular weight of compound E, measured by FAB-MS, was 669. .

[0139] (Synthesis of compound 10) Under an Ar atmosphere, 40 mL of anhydrous t-butylbenzene solution containing 5.03 g (7.5 mmol) of compound E was added to a 300 mL three-necked flask and stirred at -78°C. 15.8 mL (30 mmol) of 1.9 M t-BuLi pentane solution was added dropwise. After the addition was complete, the temperature was raised to 60°C and stirred for 2 hours, then components with lower boiling points than t-butylbenzene were removed under reduced pressure. The mixture was cooled to -30°C, and 1.4 mL (15 mmol) of BBr3 was added dropwise. After the addition was complete, the temperature was raised to room temperature and stirred for 2 hours. Then, the mixture was further cooled to 0°C, and 1.4 mL (8.0 mmol) of N,N-diisopropylethylamine was added dropwise. After the addition was complete, the temperature was raised to room temperature and stirred for 1 hour, then the temperature was raised to 120°C and heated and stirred for 8 hours. The reaction mixture was cooled to room temperature, and liquid-liquid was separated by adding NaOAc aqueous solution cooled in an ice bath and toluene. Next, after purification by short column chromatography (silica gel), recrystallization was performed in toluene / hexane solvent to obtain 4.00 g of compound 10 as a yellow solid (yield 83%).

[0140] Compound 10 was identified by FAB-MS and NMR. The molecular weight of compound 10, as measured by FAB-MS, was 643. 1 H-NMR (CDCl3) measurement The chemical shift values ​​δ of compound 10 measured at constant temperature were 8.01 (1H), 7.77 (1H), 7.71 (1H), 7.43 (1H), 7.31-7.16 (11H), 7.10-6.98 (13H), and 6.86-6.82 (2H).

[0141] 3. Synthesis of Compound 11 Compound 11, which is a polycyclic compound according to one embodiment of the present invention, can be synthesized, for example, by the following reaction. [ka]

[0142] (Synthesis of intermediate compound F) Under an Ar atmosphere, 100 mL of anhydrous THF solution containing 4.55 g (20 mmol) of 6-chloro-1-phenyl-1H-indole was added to a 500 mL three-necked flask and stirred at -78°C. Then, 13 mL (21 mmol) of 1.6 M n-BuLi solution in hexane was added dropwise, and the mixture was stirred for 2 hours. To this, 20 mL of anhydrous THF solution containing 5.33 g (21 mmol) of iodine was added dropwise, and the mixture was stirred at -78°C for 2 hours, followed by stirring at room temperature for 3 hours. After the reaction, the mixture was washed with water. The resulting organic phase was concentrated to obtain a viscous substance. The crude product was purified by column chromatography (silica gel) to obtain 6.00 g (85% yield) of compound F as a white solid. The molecular weight of compound F, measured by FAB-MS, was 353.

[0143] (Synthesis of intermediate compound G) Under an Ar atmosphere, 5.98 g (16.9 mol) of compound F and 4.78 g (16.9 mol) of 2-bromo-5-chloro-N-phenylbenzeneamine were added to a 300 mL three-necked flask. 0.16 g (0.17 mmol) of Pd2(dba)3, 0.25 g (0.34 mmol) of dppf, and 1.79 g (18.6 mmol) of NaOtBu were added, and the mixture was stirred in 85 mL of toluene at 80°C for 6 hours. After cooling in air, water was added to separate the organic layer, and the solvent was removed. The resulting crude product was purified by column chromatography (silica gel) to obtain 4.96 g (yield 58%) of compound G as a white solid. The molecular weight of compound G, as measured by FAB-MS, was 506.

[0144] (Synthesis of intermediate compound H) Under an Ar atmosphere, 100 mL of anhydrous THF solution of compound G 4.93 g (9.7 mmol) was added to a 500 mL three-necked flask and stirred at -78 °C. 12.5 mL (20 mmol) of 1.6 M n-BuLi hexane solution was added dropwise and stirred for 2 hours. Then, 1.0 mL (10 mmol) of BBr3 was added dropwise and stirred at -78 °C for 1 hour, followed by stirring at room temperature for 3 hours. After cooling to 0 °C, 10 mL (10 mmol) of 1.0 M 2,4,6-triisopropylphenylmagnesium bromide THF solution was added dropwise and stirred at 0 °C for 2 hours, followed by stirring at room temperature for 3 hours. After the reaction, the mixture was washed with water. The resulting organic phase was concentrated to obtain a viscous substance. The crude product was purified by column chromatography (silica gel) to obtain 4.36 g (70% yield) of compound H as a yellow solid. The molecular weight of compound H, as measured by FAB-MS, was 640.

[0145] (Synthesis of Compound 11) Under an Ar atmosphere, 4.35 g (6.8 mol) of compound H, 2.30 g (13.6 mmol) of diphenylamine, 0.31 g (0.34 mmol) of Pd2(dba)3, 0.63 g (1.36 mmol) of Ruphos, and 1.44 g (15.0 mmol) of NaOtBu were added to a 200 mL three-necked flask and stirred at 110 °C for 8 hours in 70 mL of toluene. After cooling in air, water was added to separate the organic layer, and the solvent was removed by rinsing. The resulting crude product was then colored. After purification by muchromatography (silica gel), 3.20 g of compound 11 was obtained as a yellow solid (yield 52%).

[0146] Compound 11 was identified by FAB-MS and NMR. The molecular weight of compound 11, as measured by FAB-MS, was 906. 1 H-NMR (CDCl3) measurement The chemical shift values ​​δ of compound 11 measured at constant temperature were 8.39 (1H), 7.69-7.56 (5H), 7.31-7.22 (12H), 7.10-6.98 (15H), 6.86-6.81 (2H), 6.40 (1H), 2.90-2.85 (3H), and 1.22-1.16 (18H).

[0147] 4. Synthesis of Compound 12 Compound 12, which is a polycyclic compound according to one embodiment of the present invention, can be synthesized, for example, by the following reaction. [ka]

[0148] (Synthesis of intermediate compound I) Under an Ar atmosphere, 9.86 g (50 mol) of p,p'-ditolylamine, 10.65 g (50 mmol) of 2-bromo-benzo[b]thiophene, 0.46 g (0.50 mmol) of Pd2(dba)3, 0.93 g (2.0 mmol) of Ruphos, and 5.29 g (55 mmol) of NaOtBu were added to a 500 mL three-necked flask and stirred at 100 °C for 2 hours in 250 mL of toluene. After cooling in air, water was added to separate the organic layer, and the solvent was removed. The resulting crude product was purified by column chromatography (silica gel) to obtain 15.15 g (92% yield) of compound I as a white solid. The molecular weight of compound I, as measured by FAB-MS, was 329.

[0149] (Synthesis of intermediate compound K) 15.13 g (46 mmol) of compound I and 25.45 g (143 mmol) of N-bromosuccinimide were added to a 1000 mL round-bottom flask. 30 mL of acetic acid was added, and the mixture was stirred in 30 mL of chloroform at 0°C for 2 hours. After cooling, an aqueous sodium thiosulfate solution was added to separate the organic layer, and the solvent was removed. After purification by column chromatography (silica gel), 23.16 g (89% yield) of compound K was obtained as a white solid. The molecular weight of compound K, as measured by FAB-MS, was 562.

[0150] (Synthesis of Compound 12) Under an Ar atmosphere, 160 mL of anhydrous t-butylbenzene solution containing 23.13 g (40.9 mmol) of compound A was added to a 1000 mL three-necked flask and stirred at -78°C. 129 mL (245 mmol) of 1.9 M t-BuLi pentane solution was added dropwise. After the addition was complete, the temperature was raised to room temperature and stirred for 2 hours. Then, the mixture was cooled to -30°C and 7.8 mL (82 mmol) of BBr3 was added dropwise. After the addition was complete, the temperature was raised to room temperature and stirred for 1 hour. Then, the mixture was further cooled to 0°C and 14.9 mL (82 mmol) of 1,2,2,6,6-pentamethylpiperidine was added dropwise. After the addition was complete, the temperature was raised to room temperature. After stirring for 1 hour, the temperature was raised to 160°C and the mixture was heated and stirred for 10 hours. The reaction mixture was cooled to 0°C, and 164 mL (164 mmol) of a 1.0 M THF solution of 2,4,6-triisopropylphenylmagnesium bromide was added dropwise. The mixture was stirred at 0°C for 2 hours, and then stirred at room temperature for 3 hours. After the reaction, phosphate buffer (pH 6) and toluene were added and the mixture was separated. Next, the mixture was purified by column chromatography (silica gel), and then recrystallized in toluene / hexane solvent to obtain 4.55 g (19% yield) of compound 12 as a yellow solid.

[0151] Compound 12 was identified by FAB-MS and NMR. The molecular weight of compound 12, as measured by FAB-MS, was 585. Furthermore, 1 H-NMR (CDCl3) The chemical shift values ​​δ for compound 12 measured were 8.05 (1H), 7.93 (1H), 7.57-7.40 (2H), 7.19-7.11 (5H), 6.99-6.95 (4H), 2.38-2.31 (18H), and 2.20-2.16 (6H).

[0152] (Example of element creation) The polycyclic compounds 8, 10, 11, and 12 described above were used as materials for the light-emitting layer to fabricate the organic electroluminescent devices of Examples 1 to 4. The compounds used in the light-emitting layer in Examples 1 to 4 and Comparative Examples 1 to 4 are shown below. [Example Compounds] [ka]

[0153] Organic electroluminescent devices of Comparative Examples 1 to 4 were fabricated using the comparative example compounds R-1 to R-4 listed below as the material for the light-emitting layer. [Comparative Compounds] [ka]

[0154] The organic electroluminescent devices of Examples 1-4 and Comparative Examples 1-4 were patterned with ITO to a thickness of 150 nm on a glass substrate, washed with ultrapure water, and subjected to UV ozone treatment for 10 minutes. Next, HAT-CN was deposited to a thickness of 10 nm, α-NPD to a thickness of 80 nm, and mCP to a thickness of 5 nm to form hole transport regions.

[0155] Next, when forming the light-emitting layer, a polycyclic compound of one embodiment of the present invention or a comparative compound was co-deposited with DPEPO in a ratio of 20:80 to form a layer with a thickness of 20 nm. Then, a layer with a thickness of 10 nm was formed using DPEPO. In other words, in Examples 1 to 4, the light-emitting layers formed by co-depositing were deposited by mixing compounds 8, 10, 11, and 12 with DPEPO, respectively, while in Comparative Examples 1 to 4, comparative compounds R-1, R-2, R-3, and R-4 were deposited by mixing them with DPEPO.

[0156] A 30 nm thick layer of TPBi was formed on the light-emitting layer, and a 0.5 nm thick layer of LiF was formed to create an electron transport region. Next, a 100 nm thick second electrode was formed using aluminum (Al).

[0157] In the example, the hole transport region, light-emitting layer, electron transport region, and second electrode were formed using a vacuum deposition apparatus.

[0158] (Evaluation of the characteristics of organic field-emitting diodes) To evaluate the characteristics of the organic electroluminescent devices in the examples and comparative examples, the maximum emission wavelength (nm) and external quantum yield (%) were measured. These measurements were performed using a Hamamatsu Photonics C9920-11 luminance orientation characteristic analyzer. The lifetime was determined with an initial luminance of 100 cd / m². 2 This shows the half-time of brightness from 10 mA / cm², with EQE being 10 mA / cm². 2 It means the value in [location]. [Table 1]

[0159] Referring to Table 1, it can be seen that the organic electroluminescent devices of Examples 1 to 4, which use a polycyclic compound according to one embodiment of the present invention as a dopant material for the light-emitting layer, exhibit higher external quantum efficiency compared to Comparative Examples 1 to 4. Furthermore, it can be seen that the organic electroluminescent devices of Examples 1 to 4, which use a polycyclic compound according to one embodiment of the present invention as a dopant material for the light-emitting layer, achieve a longer lifespan compared to Comparative Examples 1 to 4.

[0160] Referring to the results in Table 1, it can be seen that the example compounds can be used as highly efficient, long-lived thermally delayed fluorescence materials.

[0161] In the case of an organic electroluminescent element according to one embodiment of the present invention, high luminescence efficiency is exhibited by including the polycyclic compound according to the above embodiment in the light-emitting layer.

[0162] Compared to the examples, comparative compounds R-1 to R-4 do not contain a stable heteroaryl ring in the core molecule, and therefore the organic electroluminescent devices of comparative examples 1 to 4 exhibit lower external quantum efficiency and shorter device lifetime compared to the examples.

[0163] Although preferred embodiments of the present invention have been described so far with reference, a person skilled in the art or with ordinary knowledge in the art will understand that the present invention can be modified and altered in various ways without departing from the spirit and technical domain of the invention as described in the claims below.

[0164] Therefore, the technical scope of the present invention is not limited to what is described in the detailed description of the specification, but should be determined by the claims. [Explanation of Symbols]

[0165] 10: Organic electroluminescent element EL1: First electrode EL2: Second electrode HTR: Hole transport region EML: Emitting layer ETR: Electron transport region

Claims

1. A polycyclic compound represented by the following chemical formula 4. 【Chemistry 1】 (In chemical formula 4, Ar １ and Ar １ Each of these is independently a substituted or unsubstituted phenyl group. Ring A is substituted or unsubstituted indole, or substituted or unsubstituted benzothiophene, wherein the pyrrole ring portion of the indole is condensed to form chemical formula 4, and the thiophene ring portion of the benzothiophene is condensed to form chemical formula 4. Ring B is a substituted or unsubstituted benzene ring. Ring M is a substituted or unsubstituted benzene ring. W is B.

2. First electrode and A hole transport region positioned on the first electrode, A light-emitting layer disposed on the hole transport region, An electron transport region disposed on the light-emitting layer, A second electrode is disposed on the electron transport region, The light-emitting layer comprises the polycyclic compound described in claim 1. Organic electroluminescent device.

3. The organic electroluminescent element according to claim 2, wherein the light-emitting layer emits delayed fluorescence.

4. The organic electroluminescent element according to claim 2, wherein the light-emitting layer is a thermally activated delayed fluorescence light-emitting layer.

5. The light-emitting layer emits blue light, as described in claim 2.

6. The organic electroluminescent element according to claim 2, wherein the first electrode and the second electrode each independently contain one selected from the group consisting of Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, In, Sn, and Zn, a compound containing a plurality selected from these, a mixture containing a plurality selected from these, or one or more oxides selected from these.

7. The aforementioned hole transport region is A hole injection layer is placed on the first electrode, A hole transport layer is disposed on top of the hole injection layer, Includes, The thickness of the hole injection layer is approximately 3 nm to approximately 100 nm. The organic electroluminescent device according to claim 2, wherein the thickness of the hole transport layer is about 1 nm to about 100 nm.

8. The aforementioned electron transport region is An electron transport layer disposed on the light-emitting layer, An electron injection layer disposed on the electron transport layer, Includes, The thickness of the electron transport layer is approximately 10 nm to approximately 100 nm. The organic electroluminescent element according to claim 2, wherein the thickness of the electron injection layer is approximately 0.1 nm to approximately 10 nm.

9. The organic electroluminescent element according to claim 2, wherein the thickness of the light-emitting layer is approximately 10 nm to approximately 60 nm.

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