Organic electroluminescent devices

Abstract

An organic electroluminescent device is provided. The organic electroluminescent device includes: a first electrode; a second electrode facing the first electrode; and a plurality of organic layers disposed between the first electrode and the second electrode, wherein at least one of the plurality of organic layers includes a first compound represented by Formula 1, a second compound represented by Formula 2, and a third compound represented by Formula 3, wherein Formulas 1 to 3 are defined herein.

Description

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2020-0058817, filed on May 18, 2020, which is incorporated herein by reference for all purposes, as fully set forth herein. Technical Field

[0002] Exemplary embodiments of the invention generally relate to an organic electroluminescent device, and more specifically, to an organometallic compound used in the organic electroluminescent device. Background Technology

[0003] Recently, there has been active development and use of organic electroluminescent displays (OLEDs) as image display devices. OLEDs are so-called self-emissive displays, in which holes injected from a first electrode and electrons injected from a second electrode recombine in the emitting layer to generate excitons. The generated excitons fall back to the ground state and emit light to achieve the display.

[0004] When applying organic electroluminescent devices to displays, the development of organometallic compounds as dopant materials for use as emitter layer materials is underway.

[0005] The information disclosed in this background section is only for understanding the background of the inventive concept, and therefore may contain information that does not constitute prior art. Summary of the Invention

[0006] There is a need to continue developing organometallic compounds for use in organic electroluminescent devices with optimal emission wavelengths and long lifespans.

[0007] Organic electroluminescent devices, including those made from organometallic compounds manufactured according to the principles of the invention and exemplary embodiments, have improved lifetime.

[0008] Additional features of the inventive concept will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practice of the inventive concept.

[0009] According to one aspect of the invention, an organic electroluminescent device includes: a first electrode; a second electrode facing the first electrode; and a plurality of organic layers disposed between the first electrode and the second electrode, wherein at least one of the plurality of organic layers includes a first compound represented by Formula 1, a second compound represented by Formula 2, and a third compound represented by Formula 3.

[0010] Formula 1

[0011]

[0012] In Equation 1,

[0013] M is Pt, Au, Pd, Cu, or Ag.

[0014] Y is either O or S.

[0015] Ar1, Ar2, and Ar3 are each independently an aromatic hydrocarbon ring with 6 to 30 cyclic carbon atoms, either substituted or unsubstituted, or an aromatic heterocycle with 2 to 30 cyclic carbon atoms, and Ar1 includes an aryl group, a substituted or unsubstituted alkyl group, a cyano group, and a substituted or unsubstituted aryl group as a substituent.

[0016] L1 is either a direct-connect key or N.

[0017] L2 is a direct-connect key.

[0018] L3 is a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms.

[0019] a is 0 or 1.

[0020] b is an integer between 0 and 2.

[0021] R1 is a direct bond, a hydrogen atom, a deuterium atom, an aryl group with 6 to 30 cyclic carbon atoms (substituted or unsubstituted), or a heteroaryl group with 3 to 30 cyclic carbon atoms (substituted or unsubstituted), and optionally, it is bonded to an adjacent group to form a ring.

[0022] m is an integer from 0 to 4.

[0023] Formula 2

[0024]

[0025] In Equation 2,

[0026] Ar can be a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group with 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group with 3 to 30 cyclic carbon atoms.

[0027] L is a linearly bonded, 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.

[0028] R 21 and R 22 Each group is independently 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 optionally, it is incorporated into an adjacent group to form a ring.

[0029] n1 and n2 are both independent integers from 0 to 4.

[0030] Formula 3

[0031]

[0032] In Equation 3,

[0033] R 31 R 32 R 33 R 34 R 35 and R 36 Each of the groups is independently composed of a hydrogen atom, a deuterium atom, a cyano group, a substituted silyl group, 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 optionally is attached to an adjacent group to form a ring.

[0034] Z 11 Z 12 and Z 13 Each of them is independently C or N.

[0035] The first compound can be represented by formula 1-1a or formula 1-1b:

[0036] Formula 1-1a

[0037]

[0038] Formula 1-1b

[0039]

[0040] In Equations 1-1a and 1-1b, the variables are defined here. The first compound can be represented by Equation 1-2a or Equation 1-2b:

[0041] Formula 1-2a

[0042]

[0043] Formula 1-2b

[0044]

[0045] In Equations 1-2a and 1-2b, the variables are defined here.

[0046] The first compound can be represented by formula 1-3a or formula 1-3b:

[0047] Formula 1-3a

[0048]

[0049] Formula 1-3b

[0050]

[0051] In Equations 1-3a and 1-3b, the variables are defined here.

[0052] The first compound can be represented by formula 1-4a or formula 1-4b:

[0053] Formula 1-4a

[0054]

[0055] Formula 1-4b

[0056]

[0057] In Equations 1-4a and 1-4b, the variables are defined here.

[0058] The first compound can be represented by equations 1-5:

[0059] Formula 1-5

[0060]

[0061] In Equation 1-5, the variables are defined here.

[0062] The first compound can be represented by equations 1-6:

[0063] Formula 1-6

[0064]

[0065] In Equations 1-6, the variables are defined here.

[0066] The first compound can be represented by formula 1-7a or formula 1-7b:

[0067] Formula 1-7a

[0068]

[0069] Formula 1-7b

[0070]

[0071] In Equations 1-7a and 1-7b, the variables are defined here.

[0072] The plurality of organic layers may include a hole transport region, an emission layer, and an electron transport region, and the emission layer may include a first compound to a third compound.

[0073] The emitting layer can be configured to emit phosphorescence.

[0074] The emitter layer may include a host and a dopant, and the dopant may include a first compound.

[0075] The hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, and a hole blocking enhancement layer, and the electron transport region may include an electron injection layer, an electron transport layer, a hole blocking layer, and an electron blocking enhancement layer.

[0076] The first compound may include at least one compound represented by compound group 1, wherein the variable is defined herein.

[0077] The second compound may include at least one compound represented by the group of compounds H1, wherein the variables are defined herein.

[0078] The third compound may include at least one compound represented by the group of compounds H2, wherein the variables are defined herein.

[0079] According to another aspect of the invention, an organic electroluminescent device includes: a first electrode; a second electrode facing the first electrode; and a plurality of organic layers disposed between the first electrode and the second electrode, wherein at least one of the plurality of organic layers includes a first compound represented by formula A or formula B, a second compound represented by formula 2, and a third compound represented by formula 3.

[0080] Formula A

[0081]

[0082] Formula B

[0083]

[0084] Among them, in equations A and B,

[0085] M is Pt, Au, Pd, Cu, or Ag.

[0086] Ar 11 Ar 12 Ar2 and Ar3 are each independently an aromatic hydrocarbon ring with 6 to 30 cyclic carbon atoms, either substituted or unsubstituted, or an aromatic heterocycle with 2 to 30 cyclic carbon atoms, either substituted or unsubstituted.

[0087] X1, X2, X3, and X4 are each independently N or C.

[0088] Y is either O or S.

[0089] R 1s and R 2sEach of the following groups is independently an aryl group, a substituted or unsubstituted alkyl group, a cyano group, and a substituted or unsubstituted aryl group, or a substituted borazine group.

[0090] L1 is either a direct-connect key or N.

[0091] L2 is a direct-connect key.

[0092] L3 is a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms.

[0093] a is 0 or 1.

[0094] b is an integer between 0 and 2.

[0095] R1 is a direct bond, a hydrogen atom, a deuterium atom, an aryl group with 6 to 30 cyclic carbon atoms (substituted or unsubstituted), or a heteroaryl group with 3 to 30 cyclic carbon atoms (substituted or unsubstituted), and optionally, it is bonded to an adjacent group to form a ring.

[0096] m is an integer from 0 to 4.

[0097] Formula 2

[0098]

[0099] In Equation 2,

[0100] Ar can be a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group with 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group with 3 to 30 cyclic carbon atoms.

[0101] L is a linearly bonded, 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.

[0102] R 21 and R 22 Each group is independently 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 optionally, it is incorporated into an adjacent group to form a ring.

[0103] n1 and n2 are both independent integers from 0 to 4, and

[0104] Formula 3

[0105]

[0106] In Equation 3,

[0107] R 31 R32 R 33 R 34 R 35 and R 36 Each of the groups is independently composed of a hydrogen atom, a deuterium atom, a cyano group, a substituted silyl group, 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 optionally, is incorporated into an adjacent group to form a ring.

[0108] Z 11 Z 12 and Z 13 Each of them is independently C or N.

[0109] variable R 1s and R 2s It can be expressed independently of any one of equations S1 to S3:

[0110]

[0111] In equations S1 to S3, the variables are defined here.

[0112] variable R 1s and R 2s Each may independently include at least one substituent represented by group R, wherein the variable is defined herein.

[0113] According to another aspect of the invention, an organometallic compound for use in organic electroluminescent devices is represented by formula A or formula B:

[0114] Formula A

[0115]

[0116] Formula B

[0117]

[0118] Among them, in equations A and B,

[0119] M is Pt, Au, Pd, Cu, or Ag.

[0120] Ar 11 Ar 12 Ar2 and Ar3 are each independently an aromatic hydrocarbon ring with 6 to 30 cyclic carbon atoms, either substituted or unsubstituted, or an aromatic heterocycle with 2 to 30 cyclic carbon atoms, either substituted or unsubstituted.

[0121] X1, X2, X3, and X4 are each independently N or C.

[0122] Y is either O or S.

[0123] R 1s and R 2s Each of the following groups is independently an aryl group, a substituted or unsubstituted alkyl group, a cyano group, and a substituted or unsubstituted aryl group, or a substituted borazine group.

[0124] L1 is either a direct-connect key or N.

[0125] L2 is a direct-connect key.

[0126] L3 is a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms.

[0127] a is 0 or 1.

[0128] b is an integer between 0 and 2.

[0129] R1 is a direct bond, a hydrogen atom, a deuterium atom, an aryl group with 6 to 30 cyclic carbon atoms (substituted or unsubstituted), or a heteroaryl group with 3 to 30 cyclic carbon atoms (substituted or unsubstituted), and optionally, it is bonded to an adjacent group to form a ring.

[0130] m is an integer from 0 to 4.

[0131] Organometallic compounds represented by formula A or formula B may independently include at least one compound represented by group 1 of compounds, wherein the compounds are defined herein.

[0132] It will be understood that both the foregoing general description and the following detailed description are exemplary and illustrative, and are intended to provide further explanation of the claimed invention. Attached Figure Description

[0133] The accompanying drawings illustrate exemplary embodiments of the invention and, together with the description, serve to explain the inventive concept. The drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification.

[0134] Figure 1 This is a cross-sectional view schematically illustrating an exemplary embodiment of an organic electroluminescent device constructed according to the principles of the invention.

[0135] Figure 2 This is a cross-sectional view schematically illustrating an exemplary embodiment of an organic electroluminescent device constructed according to the principles of the invention.

[0136] Figure 3 This is a cross-sectional view schematically illustrating an exemplary embodiment of an organic electroluminescent device constructed according to the principles of the invention.

[0137] Figure 4This is a cross-sectional view schematically illustrating an exemplary embodiment of an organic electroluminescent device constructed according to the principles of the invention.

[0138] Figure 5 This is a cross-sectional view schematically illustrating an exemplary embodiment of an organic electroluminescent device constructed according to the principles of the invention. Detailed Implementation

[0139] In the following description, numerous specific details are set forth for illustrative purposes to provide a thorough understanding of various exemplary embodiments or implementations of the invention. As used herein, “embodiment” and “implementation” are interchangeable terms for non-limiting examples of devices or methods employing one or more inventive concepts disclosed herein. However, it will be apparent that various exemplary embodiments may be practiced without these specific details or with one or more equivalent arrangements. In other instances, well-known structures and apparatuses are shown in block diagram form to avoid unnecessarily obscuring the various exemplary embodiments. Furthermore, the various exemplary embodiments may differ, but are not necessarily exclusive. For example, a particular shape, construction, and characteristic of an exemplary embodiment may be used or implemented in another exemplary embodiment without departing from the inventive concept.

[0140] Unless otherwise stated, the exemplary embodiments shown are to be understood as providing exemplary features of different details of some ways in which the inventive concept can be implemented in practice. Therefore, unless otherwise stated, features, components, modules, layers, films, panels, regions, plates and / or aspects (hereinafter individually or collectively referred to as “elements”) of various embodiments may be additionally combined, separated, interchanged and / or rearranged without departing from the inventive concept.

[0141] Crosshairs and / or shading are typically used in accompanying drawings to clearly define the boundaries between adjacent elements. Thus, unless otherwise stated, the presence or absence of crosshairs or shading does not convey or indicate any preference or requirement for the specific material, material properties, dimensions, scale, commonalities between illustrated elements, and / or any other characteristics, properties, etc. Furthermore, in the accompanying drawings, the dimensions and relative dimensions of elements may be exaggerated for clarity and / or descriptive purposes. A particular process sequence may be performed differently than the described sequence when exemplary embodiments can be implemented differently. For example, two consecutively described processes may be performed substantially simultaneously or in the reverse order of the described sequence. Moreover, the same reference numerals denote the same elements.

[0142] When a component or layer is referred to as being "on," "connected to," or "bonded to" another component or layer, the component or layer may be directly on, directly connected to, or directly bonded to the other component or layer, or there may be intermediate components or layers present. However, when a component or layer is referred to as being "directly on," "directly connected to," or "directly bonded to" another component or layer, there are no intermediate components or layers present. Therefore, the term "connection" can refer to a physical connection, electrical connection, and / or fluid connection, with or without intermediate components. Furthermore, the D1, D2, and D3 axes are not limited to the three axes of a Cartesian coordinate system (such as the x, y, and z axes) but can be interpreted in a broader sense. For example, the D1, D2, and D3 axes can be perpendicular to each other, or they can represent different directions that are not perpendicular to each other. For the purposes of this disclosure, “at least one of X, Y, and Z” and “at least one from the group consisting of X, Y, and Z” can be interpreted as only X, only Y, only Z, or any combination of two or more of X, Y, and Z, such as XYZ, XYY, YZ, and ZZ. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0143] Although the terms “first,” “second,” etc., may be used herein to describe various types of elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. Therefore, without departing from the publicly stated teachings, the first element discussed below may be referred to as the second element.

[0144] For descriptive purposes, spatial relative terms such as “below,” “under,” “below,” “down,” “above,” “above,” “higher,” and “side” (e.g., as in a “sidewall”) may be used herein to describe the relationship of one element to another as shown in the accompanying drawings. In addition to the orientations depicted in the drawings, the spatial relative terms are intended to encompass different orientations of the device during use, operation, and / or manufacture. For example, if the device in the drawings is flipped, an element described as “below” or “under” other elements or features would subsequently be positioned “above” said other elements or features. Thus, the exemplary term “below” can include both above and below orientations. Furthermore, the device may be otherwise positioned (e.g., rotated 90 degrees or in other orientations), and the spatial relative descriptive terms used herein shall be interpreted accordingly.

[0145] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well. Furthermore, when the terms “comprising” and / or “including” and variations thereof are used in this specification, it indicates the presence of stated features, fixed numbers, integrals, steps, processes, operations, elements, components, and / or groups thereof, but does not preclude the presence or addition of one or more other features, fixed numbers, integrals, steps, processes, operations, elements, components, and / or groups thereof. It should also be noted that, as used herein, the terms “basically,” “about,” and other similar terms are used as approximate terms rather than terms of degree, and are thus used to interpret inherent deviations in measurements, calculated values, and / or provided values ​​that will be recognized by those skilled in the art.

[0146] Various exemplary embodiments are described herein with reference to cross-sectional and / or exploded views as schematic diagrams of idealized exemplary embodiments and / or intermediate structures. Thus, variations in shape of the illustrations will be expected, for example, due to manufacturing techniques and / or tolerances. Therefore, the exemplary embodiments disclosed herein should not be construed as limited to the specific shapes shown for the regions, but will include deviations in shape due to, for example, manufacturing processes. In this way, the regions shown in the figures may be schematic in nature, and the shapes of these regions may not reflect the actual shapes of the regions of the device, and are thus not intended to be limiting.

[0147] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure is a part. Terms (such as those defined in general dictionaries) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant field, and shall not be interpreted in an idealized or overly formal sense, unless expressly defined herein.

[0148] Figures 1 to 5 A cross-sectional view schematically illustrating an exemplary embodiment of an organic electroluminescent device constructed according to the principles of the invention. (Refer to...) Figures 1 to 5 Organic electroluminescent devices 10, 20, 30, 40 and 50 may include a first electrode EL1, a hole transport region HTR, an emitter layer EML, an electron transport region ETR and a second electrode EL2, which are stacked sequentially.

[0149] The first electrode EL1 and the second electrode EL2 face each other, and a plurality of organic layers may be disposed between the first electrode EL1 and the second electrode EL2. The plurality of organic layers may include a hole transport region HTR, an emitter layer EML, and an electron transport region ETR. The organic electroluminescent device 10 may include, in at least one of the plurality of organic layers, an organometallic compound (or a first compound), a first host (or a second compound), and a second host (or a third compound), as described below.

[0150] and Figure 1 compared to, Figure 2 A cross-sectional view of an organic electroluminescent device 20 is shown, wherein the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL, and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL. Additionally, with Figure 1 compared to, Figure 3 A cross-sectional view of an organic electroluminescent device 30 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 compared to, Figure 4 A cross-sectional view of an organic electroluminescent device 40, including a capping layer CPL disposed on the second electrode EL2, is shown. Figure 3 compared to, Figure 5 A cross-sectional view of an organic electroluminescent device 50 is shown, comprising a hole blocking enhancement layer BRL1 disposed below the emitter layer EML and an electron blocking enhancement layer BRL2 disposed above the emitter layer EML.

[0151] The first electrode EL1 is conductive. The first electrode EL1 can be formed of a metal alloy or a conductive compound. The first electrode EL1 can be an anode. Alternatively, the first electrode EL1 can be a pixel electrode. The first electrode EL1 can be a transmissive electrode, a transmissive-reflective electrode, or a reflective electrode. When the first electrode EL1 is a transmissive electrode, it can include transparent metal oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and indium tin zinc oxide (ITZO). When the first electrode EL1 is a transmissive-reflective electrode or a reflective electrode, it can include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF, Mo, Ti, compounds thereof, or mixtures thereof (e.g., a mixture of Ag and Mg). Optionally, the first electrode EL1 can have a multilayer structure, comprising a reflective layer or a transmissive-reflective layer formed of the above materials and a transparent conductive layer formed of ITO, IZO, ZnO, ITZO, etc. For example, the first electrode EL1 may have a three-layer structure of ITO / Ag / ITO, but the exemplary embodiments are not limited thereto. The thickness of the first electrode EL1 may be approximately to approximately For example, about to approximately

[0152] A hole transport region (HTR) is disposed 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, an electron blocking layer EBL, and a hole blocking enhancement layer BRL1. The thickness of the hole transport region HTR may be, for example, approximately... to approximately

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

[0154] For example, the hole transport region HTR can have a single-layer structure of a hole injection layer HIL or a hole transport layer HTL, or a single-layer structure formed of a hole injection material and a hole transport material. Alternatively, the hole transport region HTR can have a single-layer structure formed of various different materials, or a structure in which 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 blocking enhancement layer BRL1 / hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL are stacked sequentially from the first electrode EL1, but exemplary embodiments are not limited thereto.

[0155] Hole transport regions (HTRs) can be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodget (LB) method, inkjet printing, laser printing, and laser-induced thermal imaging (LITI).

[0156] Hole injection layer (HIL) can include, for example, phthalocyanine compounds (such as copper phthalocyanine), N,N'-diphenyl-N,N'-bis[4-(di-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-phenylethyl) Poly(phenylene oxide) 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-1-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-hexaonitrile (HAT-CN), etc.

[0157] Hole transport layers (HTLs) can include, for example, carbazole derivatives (such as N-phenylcarbazole and 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-biphenylamine (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.

[0158] The thickness of the hole transport region HTR can be approximately to approximately For example, about to approximately The thickness of the hole injection layer (HIL) can be, for example, approximately to approximately Furthermore, the thickness of the hole transport layer (HTL) can be approximately to approximately For example, the thickness of the electron blocking layer (EBL) can be approximately to approximately If the thicknesses of the hole transport region (HTR), hole injection layer (HIL), hole transport layer (HTL), and electron blocking layer (EBL) meet the ranges described above, satisfactory hole transport properties can be obtained without significantly increasing the driving voltage.

[0159] In addition to the materials described above, the hole transport region (HTR) may also include a charge-generating material to improve conductivity. The charge-generating material may be uniformly or non-uniformly dispersed in the hole transport region (HTR). The charge-generating material may be, for example, a p-doper. The p-doper may be one of quinone derivatives, metal oxides, and cyano-containing compounds, but exemplary embodiments are not limited thereto. For example, non-limiting examples of p-dopers may include quinone derivatives (such as tetracyanoquinone dimethyl (TCNQ) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinone dimethyl (F4-TCNQ)), metal oxides (such as tungsten oxide and molybdenum oxide), etc., but exemplary embodiments are not limited thereto.

[0160] As described above, in addition to the hole injection layer HIL and the hole transport layer HTL, the hole transport region HTR may also include at least one of a hole buffer layer, an electron blocking layer EBL, and a hole blocking enhancement layer BRL1. The hole buffer layer can compensate for the optical resonant distance based on the wavelength of light emitted from the emitter layer EML and can increase luminous efficiency. Materials that can be included in the hole transport region HTR can be used as materials that can be included in the hole buffer layer. The electron blocking layer EBL is a layer used to prevent electrons from being injected from the electron transport region ETR into the hole transport region HTR. The hole blocking enhancement layer BRL1 can reduce the bandgap between the emitter layer EML and the hole transport region HTR. Furthermore, the hole blocking enhancement layer BRL1 can have a higher hole transport capability than the electron blocking layer EBL. In some exemplary embodiments, the hole blocking enhancement layer BRL1 may include at least one of compounds 1-1 to 1-22 of the compound group H1, but exemplary embodiments are not limited thereto. The emitter layer EML is disposed 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 be a single layer made of a single material, a single layer made of multiple different materials, or a multilayer structure including multiple layers made of multiple different materials.

[0161] The emission layer (EML) in organic electroluminescent devices can include organometallic compounds.

[0162] As used herein, the term "substituted or unsubstituted" may mean unsubstituted or substituted with at least one substituent selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amino (or amine) group, a silyl group, an oxy group (or "oxy-containing"), a thio group, a sulfinyl group, a sulfonyl group, a carbonyl group, a boron group, a phosphonooxide group, a phosphonosulfide group, an alkyl group, an alkenyl group, an alkoxy group, a cycloalkyl group, an aryl group, and a heterocyclic group. Additionally, each substituent in the examples above may be substituted or unsubstituted. For example, biphenyl may be interpreted as an aryl group or a phenyl group substituted with a phenyl group.

[0163] As used herein, the phrase "bonding to an adjacent group to form a ring" can mean bonding to an adjacent group to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle. 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. Additionally, rings formed by bonding with each other can attach to another ring to form a spirostructure.

[0164] As used herein, the phrase “to combine with an adjacent ring to form a ring” can mean that two adjacent rings combine to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocycle.

[0165] As used herein, the term "adjacent group" can mean a substituent that is directly attached to an atom of a corresponding substituent, another substituent that is attached to an atom of a corresponding substituent, or a substituent located spatially closest to the corresponding substituent. For example, in 1,2-dimethylbenzene, the two methyl groups can be interpreted as "adjacent groups" to each other, and in 1,1-diethylcyclopentane, the two ethyl groups can be interpreted as "adjacent groups" to each other.

[0166] Examples of halogen atoms, as used herein, may include fluorine, chlorine, bromine, and iodine atoms.

[0167] As used herein, alkyl groups can be straight-chain, branched, or cyclic. The number of carbon atoms in an alkyl group is from 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of alkyl groups may include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyloctyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2- Butyldecyl, 2-hexyldecyl, 2-octyldecyl, undecyl, dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl, heptadecanyl, octadecyl, nonadecanyl, eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, hexadecyl, hexadecyl, nonadecanyl, triadecyl, etc.

[0168] As used herein, the cycloalkyl group can be any functional group or substituent derived from an aliphatic hydrocarbon ring or any functional group or substituent derived from an aromatic hydrocarbon ring. The number of cyclic carbon atoms in the cycloalkyl group can be 5 to 60, 5 to 30, or 5 to 20.

[0169] As used herein, aryl means any functional group or substituent derived from an aromatic hydrocarbon ring. Aryl can be monocyclic or polycyclic. The number of cyclic carbon atoms in the aryl group can be 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups may include phenyl, naphthyl, fluorenyl, anthracene, phenanthryl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, hexaphenyl, benzo[9,10]phenanthryl, pyrene, benzofluoranthracene, etc. Examples of the above are provided, but exemplary embodiments are not limited thereto.

[0170] As used herein, a heterocyclic group refers to any functional group or substituent derived from a ring comprising at least one of B, O, S, N, P, Si, and Se as a heteroatom. Heterocyclic groups include aliphatic heterocyclic groups and aromatic heterocyclic groups. Aromatic heterocyclic groups may be heteroaryl groups. Aliphatic and aromatic heterocycles may be monocyclic or polycyclic.

[0171] When a heterocyclic group contains two or more heteroatoms, the two or more heteroatoms may be the same or different from each other. The heterocyclic group may be a monocyclic or polycyclic heterocyclic group, and may include heteroaryl groups. The number of cyclic carbon atoms in the heterocyclic group may be 2 to 30, 2 to 20, or 2 to 10.

[0172] The ring used to form the aliphatic heterocyclic group can have 2 to 30, 2 to 20, or 2 to 10 carbon atoms. Examples of aliphatic heterocyclic groups may include, but are not limited to, ethylene oxide, cyclothioethane, pyrrolidinyl, piperidinyl, tetrahydrofuranyl, tetrahydrothiophenyl, thiocyclopentyl, tetrahydropyranyl, 1,4-dioxane, etc.

[0173] As used herein, a heteroaryl group may include at least one of B, O, N, P, Se, Si, and S as a heteroatom. When a 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. Examples of heteroaryl groups may include, but are not limited to, thiopheneyl, furanyl, pyrrolyl, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridineyl, pyridazinyl, quinolinyl, quinazolinyl, quinoxazinyl, phenothiazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolinyl, indolyl, carbazoleyl, N-arylcarbazoleyl, N-heteroarylcarbazoleyl, N-alkylcarbazoleyl, benzoxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazoleyl, benzothiopheneyl, dibenzothiapheneyl, thiophenothiapheneyl, benzofuranyl, phenanthrolyl, isoxazolyl, thiadiazolyl, phenothiazolyl, phenothiazinyl, dibenzothiopheneyl, dibenzofuranyl, etc.

[0174] As used herein, silyl groups include alkylsilyl groups and arylsilyl groups. Examples of silyl groups may include, but are not limited to, trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, etc.

[0175] As used herein, the alkyl group in the alkylamine group is the same as the example of the alkyl group described above.

[0176] As used herein, the aryl group in the arylamine group is the same as the aryl group in the examples above.

[0177] As used here, a direct key can represent a single key.

[0178] As used here Indicates the location to be connected.

[0179] As used herein, the term "atom" may refer to an element or its corresponding free radical bonded to one or more other atoms.

[0180] The terms “hydrogen” and “deuterium” refer to their respective atoms and corresponding free radicals, and the terms “-F, -Cl, -Br and -I” are the free radicals of fluorine, chlorine, bromine and iodine, respectively.

[0181] As used herein, a substituent for a monovalent group (e.g., alkyl) may also be a substituent for the corresponding divalent group (e.g., alkylene).

[0182] The emitting layer (EML) of an organic electroluminescent device may include a first compound represented by Formula 1 below, a second compound represented by Formula 2 below, and a third compound represented by Formula 3 below.

[0183] The first compound is an organometallic compound represented by the following formula 1:

[0184] Formula 1

[0185]

[0186] In Equation 1 above, M can be a transition metal. Specifically, M can be Pt, Au, Pd, Cu, or Ag. For example, M can be Pt.

[0187] In Equation 1, Y is either O or S. Specifically, Y can be O.

[0188] In Formula 1, Ar1, Ar2 and Ar3 can each be independently an aromatic hydrocarbon ring with 6 to 30 cyclic carbon atoms, either substituted or unsubstituted, or an aromatic heterocycle with 3 to 30 cyclic carbon atoms.

[0189] Specifically, Ar1 can be a substituted or unsubstituted aromatic heterocycle having 2 to 30 cyclic carbon atoms. For example, Ar1 can be a substituted or unsubstituted aromatic heterocycle having 5 cyclic carbon atoms and containing a nitrogen atom. Ar1 can be a substituted or unsubstituted benzimidazole ring or a substituted or unsubstituted pyrazole ring. In some exemplary embodiments, Ar1 can be...

[0190] Specifically, Ar1 includes aryl, substituted or unsubstituted alkyl, cyano and substituted or unsubstituted aryl groups as substituents, which are further described below as having at least one of a deuterium atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted borazine group.

[0191] Specifically, Ar2 can be a substituted or unsubstituted aromatic hydrocarbon ring having six cyclic carbon atoms, or a substituted or unsubstituted aromatic heterocycle having six cyclic carbon atoms. For example, Ar2 can be a substituted or unsubstituted benzene ring. Optionally, Ar2 can be a substituted or unsubstituted borazine group, for example, 1,3,5,2,4,6-triazaborane.

[0192] Specifically, Ar3 can be a substituted or unsubstituted aromatic heterocycle having 2 to 30 cyclic carbon atoms. For example, Ar3 can be an aromatic heterocycle having 5 or 6 cyclic carbon atoms and containing a nitrogen atom. For example, Ar3 can be a substituted or unsubstituted imidazole or a substituted or unsubstituted pyridine.

[0193] In Equation 1, L1 is a direct bond or N.

[0194] In Equation 1, L2 is a direct-connection key.

[0195] In Formula 1, L3 is a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms.

[0196] In Equation 1, a is 0 or 1, and b is an integer from 0 to 2.

[0197] Specifically, in some exemplary embodiments, when L1 is a direct key, a can be 0, and b can be 1 or 2. In some exemplary embodiments, when L1 is N, a can be 1, and b can be 0.

[0198] In Formula 1, R1 can be a direct bond, a hydrogen atom, a deuterium atom, 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 optionally, it can bind to an adjacent group to form a ring. For example, R1 is a direct bond and can directly bind to Ar3 to form a ring. Specifically, when L1 is a direct bond and a is 0, R1 can directly bind to Ar3 to form a ring.

[0199] In Equation 1, m is an integer from 0 to 4. For example, m can be 0 or 1. The case where m is 0 is the same as the case where m is 1 and R1 is a hydrogen atom.

[0200] In some exemplary embodiments, the organometallic compounds represented by Formula 1 above can be represented by Formula 1-1a or Formula 1-1b below:

[0201] Formula 1-1a

[0202]

[0203] Formula 1-1b

[0204]

[0205] Equation 1-1a above refers to the specific case where L1 is N, a is 1, and b is 0 in Equation 1 above.

[0206] Equation 1-1b above describes the specific case where L1 in Equation 1 is a direct bond and a is 0. Furthermore, Equation 1-1b above describes the specific case where m is 1 or greater, one of R1 is a direct bond, and R1, acting as the direct bond, combines with an adjacent group to form a ring. For example, R1 can form a ring by combining with Ar3 in Equation 1, and the remaining R1s are represented by R6. Therefore, o2 can be the same as m-1.

[0207] In Formulas 1-1a and 1-1b above, R5 and R6 can each independently be a hydrogen atom, a deuterium atom, 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 optionally can be attached to adjacent groups to form a ring. For example, each of R5 and R6 can be a hydrogen atom.

[0208] In equations 1-1a and 1-1b above, o1 is an integer from 0 to 4. For example, o1 can be 0 or 1. The case where o1 is 0 is the same as the case where o1 is 1 and R5 is a hydrogen atom.

[0209] In equations 1-1a and 1-1b above, o2 is an integer from 0 to 3. For example, o2 can be 0 or 1. The case where o2 is 0 is the same as the case where o2 is 1 and R6 is a hydrogen atom.

[0210] In Equations 1-1a and 1-1b above, those described in Equation 1 can be applied equivalently to M, Ar1 to Ar3, Y, L3 and b.

[0211] In some exemplary embodiments, the organometallic compounds represented by Formula 1 above can be represented by Formula 1-2a or Formula 1-2b below:

[0212] Formula 1-2a

[0213]

[0214] Formula 1-2b

[0215]

[0216] Equations 1-2a and 1-2b above describe specific cases where Ar1 in Equation 1 is a substituted or unsubstituted aromatic heterocycle with five cyclic atoms. Specifically, Ar1 can be a substituted or unsubstituted aromatic heterocycle containing a nitrogen atom as a heteroatom.

[0217] In formulas 1-2a above, R7 can be a hydrogen atom, a deuterium atom, 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 optionally, it can be bonded to an adjacent group to form a ring. For example, R7 can be a hydrogen atom. However, exemplary embodiments are not limited thereto.

[0218] In equations 1-2a above, p is an integer from 0 to 4. For example, p can be 0 or 1. The case where p is 0 is the same as the case where p is 1 and R7 is a hydrogen atom.

[0219] In equations 1-2a and 1-2b above, Ar4 and Ar5 can each be independently represented by any one of the following equations S1 to S3:

[0220]

[0221] In equations S1 to S3 above, R a R b and R c Each of the following can be independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a cyano group, or a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, and optionally, can be incorporated into an adjacent group to form a ring.

[0222] For example, R a It can be a hydrogen atom, a deuterium atom, a methyl group, a substituted or unsubstituted isopropyl group, a substituted or unsubstituted tert-butyl group, or a substituted or unsubstituted phenyl group. Specifically, R a It can be methyl, deuterated isopropyl, deuterated tert-butyl, or deuterated phenyl. However, exemplary embodiments are not limited thereto. For example, R b It can be methyl. However, the exemplary embodiments are not limited thereto.

[0223] For example, R c It can be a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms. Specifically, R c It can be a substituted or unsubstituted methyl group. For example, R c It can be a methyl group that replaces deuterium. However, exemplary embodiments are not limited thereto.

[0224] In Equations 1-2a and 1-2b above, those described in Equation 1 can be applied equivalently to M, Y, Ar2, Ar3, L1 to L3, a, b, R1 and m.

[0225] In some exemplary embodiments, the organometallic compounds represented by Formula 1 above can be represented by Formulas 1-3a or 1-3b below:

[0226] Formula 1-3a

[0227]

[0228] Formula 1-3b

[0229]

[0230] Formulas 1-3a and 1-3b above are specific examples of Ar2 in Formula 1. Specifically, Formula 1-3a describes Ar2 in Formula 1 as a substituted or unsubstituted benzene ring. Formula 1-3b describes Ar2 in Formula 1 as a substituted or unsubstituted borazine group.

[0231] In Formulas 1-3a and 1-3b, R8 and R9 can each be independently a hydrogen atom, a deuterium atom, 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 optionally, can be incorporated into adjacent groups to form a ring. For example, R8 and R9 can each be independently a hydrogen atom, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted tert-butyl group. However, exemplary embodiments are not limited thereto.

[0232] In equations 1-3a and 1-3b, q1 and q2 can each be an integer from 0 to 3 independently. For example, q1 and q2 can each be 0 or 1 independently.

[0233] In Equations 1-3a and 1-3b above, those described in Equation 1 can be applied equivalently to M, Y, Ar1 and Ar3, L1 to L3, a, b, R1 and m.

[0234] In some exemplary embodiments, the organometallic compounds represented by Formula 1 above can be represented by Formulas 1-4a or 1-4b below:

[0235] Formula 1-4a

[0236]

[0237] Formula 1-4b

[0238]

[0239] Equations 1-4a and 1-4b above are specific examples of Ar3 in Equation 1. Specifically, Equation 1-4a refers to Ar3 in Equation 1 being a substituted or unsubstituted aromatic heterocycle with 6 cyclic atoms. Equation 1-4b refers to Ar3 in Equation 1 being a substituted or unsubstituted aromatic heterocycle with 5 cyclic atoms.

[0240] In equations 1-4a and 1-4b, R 10 and R 11 Each group can independently be a hydrogen atom, a deuterium atom, 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 optionally, can be incorporated into adjacent groups to form a ring. For example, R 10 It can be tert-butyl, substituted or unsubstituted phenyl, or substituted or unsubstituted borazinyl. For example, R 11 It can be a substituted or unsubstituted tert-butyl, a substituted or unsubstituted phenyl, or a substituted or unsubstituted borazinyl. However, exemplary embodiments are not limited thereto.

[0241] In equation 1-4a, r1 is an integer from 0 to 3. For example, r1 can be 0 or 1.

[0242] In Equation 1-4b, r2 is an integer from 0 to 2.

[0243] In Equations 1-4a and 1-4b, those described in Equation 1 can be applied equivalently to M, Y, Ar1, Ar2, L1 to L3, a, b, R1 and m.

[0244] In some exemplary embodiments, the organometallic compounds represented by Formula 1 above can be represented by Formulas 1-5 below:

[0245] Formula 1-5

[0246]

[0247] Equations 1-5 above provide a specific overview of M being Pt in Equation 1. However, exemplary embodiments are not limited thereto.

[0248] In Equations 1-5, those described in Equation 1 can be applied equivalently to Y, Ar1 to Ar3, L1 to L3, a, b, R1, and m.

[0249] In some exemplary embodiments, the organometallic compounds represented by Formula 1 above can be represented by the following Formulas 1-6:

[0250] Formula 1-6

[0251]

[0252] Equations 1-6 above are specific examples of Y being 0 in Equation 1 above. However, exemplary embodiments are not limited thereto.

[0253] In Equations 1-6, those described in Equation 1 can be applied equivalently to M, Ar1 to Ar3, L1 to L3, a, b, R1 and m.

[0254] In some exemplary embodiments, the organometallic compounds represented by Formula 1 above can be represented by Formulas 1-7a or 1-7b below:

[0255] Formula 1-7a

[0256]

[0257] Formula 1-7b

[0258]

[0259] Equations 1-7a and 1-7b above are specific implementations of Ar3, L1, L2, a, and b in Equation 1 above. Specifically, Equation 1-7a is a specific implementation in Equation 1 where Ar3 is a substituted or unsubstituted aromatic heterocycle with 6 cyclic atoms, L1 is N, a is 1, L2 is a direct bond, and b is 0.

[0260] Specifically, Formula 1-7b is a specific overview of Formula 1 where Ar3 is an aromatic heterocycle with 5 cyclic atoms, either substituted or unsubstituted, L1 is a direct bond, and a is 0.

[0261] In Equations 1-7a and 1-7b, those described in Equations 1, 1-1a, 1-1b, 1-4a, and 1-4b can be equivalently applied to M, Y, Ar1, Ar2, L3, b, R5, R6, and R. 10 R 11 r1, r2, o1 and o2.

[0262] The first compound is an organometallic compound represented by either formula A or formula B:

[0263] Formula A

[0264]

[0265] Formula B

[0266]

[0267] Equation A above is represented by the substituent R of Ar1 described in Equation 1. 1s Formula B is the substituent of Ar1 described in Formula 1, expressed as R. 2s .

[0268] In equations A and B, Ar 11 and Ar 12 All are independently aromatic hydrocarbon rings with 6 to 30 cyclic carbon atoms, either substituted or unsubstituted, or aromatic heterocycles with 2 to 30 cyclic carbon atoms, either substituted or unsubstituted. Specifically, Ar 11 and Ar 12 It can be an aromatic heterocycle with 2 to 30 cyclic carbon atoms, each independently substituted or unsubstituted.

[0269] For example, Ar 11 and Ar 12 Each of them can be an aromatic heterocycle with five cyclic carbon atoms, either substituted or unsubstituted, and can be independently substituted.

[0270] In equations A and B, X1, X2, X3, and X4 are each independently N or C. For example, X1 can be N. X2 can be N or C. X3 can be N or C. X4 can be C. However, the exemplary embodiments are not limited thereto.

[0271] In equations A and B, R 1s and R 2s Each is independently an aryl group, substituted or unsubstituted alkyl group, cyano group, or substituted or unsubstituted aryl group, selected from at least one of the following: substituted deuterium atom, substituted or unsubstituted alkyl group, or substituted borazine group. For example, R 1s and R 2s It can be represented by at least one of the following equations S1 to S3:

[0272]

[0273] In equations S1 to S3 above, R a R b and R c Each group may be independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a cyano group, or a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, and optionally, may be incorporated into an adjacent group to form a ring.

[0274] For example, R a It can be a hydrogen atom, a deuterium atom, a methyl group, a substituted or unsubstituted isopropyl group, a substituted or unsubstituted tert-butyl group, or a substituted or unsubstituted phenyl group. Specifically, R a It can be a deuterated isopropyl group, a deuterated tert-butyl group, or a deuterated phenyl group. However, the exemplary embodiments are not limited thereto.

[0275] For example, R b It can be methyl. However, the exemplary embodiments are not limited thereto.

[0276] For example, R cIt can be a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms. Specifically, R c It can be a substituted or unsubstituted methyl group. For example, R c It can be a methyl group that replaces deuterium. However, exemplary embodiments are not limited thereto.

[0277] While not wishing to be bound by theory, some exemplary organometallic compounds include, for example, R 1s and R 2s Substituents can introduce steric hindrance, thereby reducing intermolecular interactions and increasing molecular stability.

[0278] In some exemplary embodiments, R 1s and R 2s Each may include at least one of the substituents represented by the group R below:

[0279] Group R

[0280]

[0281]

[0282] In Equations A and B, those described in Equation 1 can be applied equivalently to M, Y, Ar2, Ar3, L1 to L3, a, b, R1, and m.

[0283] In some exemplary embodiments, the first compound may include at least one of the compounds represented by the following group 1:

[0284] Compound group 1

[0285]

[0286]

[0287]

[0288] exist Figures 1 to 5 In the organic electroluminescent device shown, the emission layer EML may include a host and a dopant, and the emission layer EML may include a first compound, a second compound, and a third compound.

[0289] The first compound can be an organometallic compound. The organometallic compound can be a phosphorescent dopant. The emission layer (EML) can emit phosphorescence.

[0290] The second and third compounds can be the main components.

[0291] In some exemplary embodiments, the second compound may be represented by the following formula 2:

[0292] Formula 2

[0293]

[0294] In Formula 2 above, Ar is a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group with 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group with 3 to 30 cyclic carbon atoms. For example, Ar can be an arylsilyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted anthraquinone group, a substituted or unsubstituted benzo[9,10]phenanthyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted carbazole group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted dibenzothiophene group. However, exemplary embodiments are not limited thereto.

[0295] In Formula 2, L is a linearly linked, 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. For example, L is phenylene, biphenylene, or divalent anthracene. However, exemplary embodiments are not limited thereto.

[0296] In Equation 2 above, R 21 and R 22 Each group can be independently 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 optionally, can be incorporated into adjacent groups to form a ring. For example, R 21 and R 22 They can all be independently substituted or unsubstituted phenyl groups or substituted or unsubstituted carbazole groups.

[0297] In Equation 2 above, n1 and n2 are both independent integers from 0 to 4.

[0298] In some exemplary embodiments, the second compound represented by Formula 2 may include at least one of the compounds represented by the following group of compounds H1:

[0299] Compound group H1

[0300]

[0301]

[0302] In some exemplary embodiments, the third compound may be represented by the following formula 3:

[0303] Formula 3

[0304]

[0305] In Equation 3 above, R 31 R 32R 33 R 34 R 35 and R 36 Each group can independently be a hydrogen atom, a deuterium atom, a cyano group, a substituted silyl group, 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 optionally, can be attached to an adjacent group to form a ring. For example, R 31 R 32 R 33 R 34 R 35 and R 36 Each can be independently a hydrogen atom, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted carbazole group.

[0306] In Equation 3 above, Z 11 Z 12 and Z 13 Each is independently C or N.

[0307] In some exemplary embodiments, the third compound represented by Formula 3 may include at least one of the compounds represented by the following group of compounds H2:

[0308] Compound group H2

[0309]

[0310]

[0311] An organic electroluminescent device according to some exemplary embodiments includes a first compound as a dopant material and a second and a third compound as host materials.

[0312] The emitter layer EML may include one, two, or more organometallic compounds of group 1 as described above. In addition to the organometallic compounds described above, the emitter layer EML may also include known materials.

[0313] In addition to the organometallic compounds described above, the emitter layer (EML) in an organic electroluminescent device may also include known dopant materials. In some exemplary embodiments, the emitter layer (EML) may also include the following compounds as dopant materials: styrene derivatives (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4'-[(di-p-tolylamino)styrene]benzene (DPAVB) and N-(4-((E)-2-(6-((E)-4-(diphenylamino)styrene)naphth-2-yl)vinyl)phenyl)-N-phenylaniline (N-BDAVBi)), perylene and its derivatives (e.g., 2,5,8,11-tetratert-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1'-dipyrene, 1,4-dipyrenebenzene, 1,4-bis(N,N-diphenylamino)pyrene), etc.

[0314] In addition to the organometallic compounds described above, the emission layer (EML) in an organic electroluminescent device may also include known fluorescent dopant materials. For example, it may include fluorescent dopant compounds from the following compound group F.

[0315] Compound group F

[0316]

[0317]

[0318] The emitter layer EML can use materials known in the art as the host material without limitation. For example, the emitter layer EML may include at least one of bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), 1,3-bis(carbazole-9-yl)benzene (mCP), 2,8-bis(diphenylphosphino)dibenzo[b,d]furan (PPF), 4,4',4”-tris(carbazole-9-yl)-triphenylamine (TCTA), or 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBi). However, exemplary embodiments are not limited thereto, and may also include, for example, tris(8-hydroxyquinoline)aluminum (Alq3), 4,4'-bis(N-carbazole)-1,1'-biphenyl (CBP). Poly(N-vinylcarbazole) (PVK), 9,10-bis(naphthyl-2-yl)anthracene (ADN), 2-tert-butyl-9,10-bis(naphthyl-2-yl)anthracene (TBADN), stilbeneyl arylene (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl (CDBP), 2-methyl-9,10-bis(naphthyl-2-yl)anthracene (MADN), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetrasiloxane (DPSiO4) and other similar materials are used as main materials.

[0319] exist Figures 1 to 5 In the organic electroluminescent device shown, the electron transport region (ETR) is disposed on the emitter layer (EML). The electron transport region (ETR) may include at least one of the electron blocking enhancement layer (BRL2), the hole blocking layer (HBL), the electron transport layer (ETL), and the electron injection layer (EIL), but the exemplary embodiments are not limited thereto.

[0320] The electronic transport region (ETR) can have a single layer made of a single material, a single layer made of multiple different materials, or a multi-layer structure including multiple layers made of multiple different materials.

[0321] For example, the electron transport region (ETR) can have a single-layer structure of an electron injection layer (EIL) or an electron transport layer (ETL), and can have a single-layer structure formed of an electron injection material and an electron transport material. Alternatively, the ETR can have a single-layer structure formed of various different materials, or can have a structure in which electron transport layer (ETL) / electron injection layer (EIL), hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL), or electron blocking reinforcement layer (BRL2) / hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL) are stacked sequentially from the emitter layer (EML), but exemplary embodiments are not limited thereto. The thickness of the electron transport region (ETR) can be, for example, approximately... to approximately

[0322] Electron transport regions (ETRs) can be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodget (LB) method, inkjet printing, laser printing, and laser-induced thermal imaging (LITI).

[0323] When the electron transport region (ETR) includes an electron transport layer (ETL), the ETL may include anthracene compounds. However, exemplary embodiments 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- Phenophenanthrene (Bphen), 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthyl-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum (BAlq), bis(benzoquinoline-10-hydroxy)beryllium (Bebq2), 9,10-bis(naphthyl-2-yl)anthracene (ADN), or mixtures thereof. The thickness of the electron transport layer (ETL) can be approximately... to approximately For example, about to approximately If the thickness of the electron transport layer (ETL) meets the above range, satisfactory electron transport characteristics can be obtained without significantly increasing the driving voltage.

[0324] If the electron transport region (ETR) includes an electron injection layer (EIL), the EIL can be formed using metal halides (such as LiF, NaCl, CsF, RbCl, and RbI), lanthanides (such as Yb), metal oxides (such as Li₂O and BaO), lithium hydroxyquinoline (Liq), etc., but exemplary embodiments are not limited thereto. The EIL can also be formed from a mixture of an electron transport material and an insulating organometallic salt. The organometallic salt can be a material having a band gap of about 4 eV or greater. Specifically, the organometallic salt can include, for example, metal acetates, metal benzoates, metal acetoacetates, metal acetylacetonates, or metal stearates. The thickness of the EIL can be approximately... to approximately For example, about to approximately If the thickness of the electron injection layer (EIL) meets the above range, satisfactory electron injection characteristics can be obtained without significantly increasing the driving voltage.

[0325] The electron transport region (ETR) may include a hole blocking layer (HBL) as described above. The hole blocking layer (HBL) may include at least one of, for example, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and 4,7-diphenyl-1,10-phenanthroline (Bphen), but exemplary embodiments are not limited thereto.

[0326] Additionally, the electron transport region (ETR) may include an electron blocking enhancement layer (BRL2). The BRL2 can reduce the bandgap between the emitter layer (EML) and the ETR. Furthermore, the BRL2 may have a higher electron mobility than the hole blocking layer (HBL). In some exemplary embodiments, the BRL2 may include at least one of compounds 2-1 to 2-29 of the compound group H2, but the exemplary embodiments are not limited thereto.

[0327] The second electrode EL2 is disposed on the electron transport region ETR. The second electrode EL2 can be a common electrode or a cathode electrode. The second electrode EL2 can be a transmission electrode, a transmission-reflection electrode, or a reflection electrode. When the second electrode EL2 is a transmission electrode, the second electrode EL2 can be formed of a transparent metal oxide (e.g., ITO, IZO, ZnO, ITZO, etc.).

[0328] 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, or compounds or mixtures thereof (e.g., a mixture of Ag and Mg). Optionally, the second electrode EL2 may have a multilayer structure, which includes a reflective or transmissive layer formed of the above materials and a transparent conductive layer formed of ITO, IZO, ZnO, ITZO, etc.

[0329] The second electrode EL2 can be connected to the auxiliary electrode. When the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 can be reduced.

[0330] The capping layer CPL may be further disposed on the second electrode EL2 of the organic electroluminescent device in some exemplary embodiments. The capping layer CPL may include multiple layers or a single layer.

[0331] The capping layer CPL can be an organic layer or an inorganic layer. For example, when the capping layer CPL includes inorganic materials, the inorganic materials may include alkali metal compounds (such as LiF) and alkaline earth metal compounds (such as MgF2, SiON, SiN). x SiO y wait).

[0332] For example, when the capping layer CPL comprises an organic material, the organic material may include 2,2′-dimethyl-N,N′-bis[(1-naphthyl)-N,N′-diphenyl]-1,1′-biphenyl-4,4′-diamine (α-NPD), NPB, TPD, m-MTDATA, Alq3, copper(II) phthalocyanine (CuPc), N4,N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine (TPD15), 4,4',4"-tris(carbazole-9-yl)triphenylamine (TCTA), or epoxy resins or acrylates (such as methacrylates). However, exemplary embodiments are not limited thereto, and the organic material may also include compounds P1 to P5 listed below.

[0333]

[0334]

[0335] The organic electroluminescent device may also include the aforementioned organometallic compound in at least one organic layer disposed between the first electrode EL1 and the second electrode EL2 or in a capping layer CPL disposed on the second electrode EL2.

[0336] While not wishing to be bound by theory, organic electroluminescent devices constructed according to the principles and exemplary embodiments of the invention include substituents that induce steric hindrance, thereby reducing intermolecular interactions and increasing molecular stability. When organometallic compounds manufactured according to the principles and exemplary embodiments of the invention are used in the emitter layer, organic electroluminescent devices can exhibit improved device lifetime and low drive voltage characteristics.

[0337] In the following description, with reference to examples and comparative examples, organometallic compounds manufactured according to some exemplary embodiments, organic electroluminescent devices according to some exemplary embodiments, and organometallic compounds used in organic electroluminescent devices will be described in detail. Furthermore, the examples shown below are provided merely for understanding the invention, and the scope of the invention is not limited thereto.

[0338] Example

[0339] 1. Synthesis of organometallic compounds

[0340] For example, organometallic compounds according to exemplary embodiments can be synthesized as follows. However, exemplary embodiments of the methods for synthesizing organometallic compounds are not limited thereto.

[0341] Synthesis Example 1: Synthesis of Compound 1

[0342] Reaction diagram 1

[0343]

[0344] (1) Synthesis of intermediate A

[0345] 3-(tert-butyl)-5-(3-(4',6'-di-tert-butyl-[1,1':3',1”-terphenyl]-2'-yl-2,2”,3,3”,4,4”,5,5”,6,6”-d10)-2,3-dihydro-1H-benzo[d]imidazol-1-yl)phenol (1 eq), 3-bromo-9-(4-(tert-butyl)pyridin-2-yl)-9H-carbazole (1 eq), copper iodide (0.1 equivalence (eq)), potassium phosphate (2.0 eq), and L-proline (0.1 eq) were added to 100 mL of dimethylformamide solvent, heated to 120 °C, and stirred for 12 hours. The reaction mixture was extracted with dichloromethane and distilled water. The organic layer was washed three times with distilled water, dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure. The concentrated solution was separated by column chromatography to obtain intermediate A in 68% yield.

[0346] For C 64 H 56 D 10 HRMS of N4O[M]+: Calculated value (calcd): 917, Found value: 916

[0347] (2) Synthesis of Compound 1

[0348] The synthesized intermediate A (1 eq), sodium acetate (3.0 eq), and dichloro(1,5-cyclooctadiene)platinum(II))(Pt(COD)Cl2)(1.1 eq) were suspended in a 1,4-dioxane solvent. The reaction mixture was heated to 120 °C and stirred for 12 hours. After the reaction was complete, the solvent was removed under reduced pressure. The product was purified by column chromatography to obtain the compound in 40% yield.

[0349] For C 64 H 53 D 10 HRMS of N4OPt[M]+: Calculated value: 1109, Found value: 1108

[0350] Elemental analysis of the calculated values: C, 69.29; H, 6.63; N, 5.05; O, 1.44; Pt, 17.58

[0351] Synthesis Example 2: Synthesis of Compound 2

[0352] Reaction diagram 2

[0353]

[0354] (3) Synthesis of intermediate B

[0355] Except that 3-(tert-butyl)-5-(3-(4',6'-dimethyl-[1,1':3',1”-terphenyl]-2'-yl-2,2”,3,3”,4,4”,5,5”,6,6”-d10)-2,3-dihydro-1H-benzo[d]imidazol-1-yl)phenol was used instead of 3-(tert-butyl)-5-(3-(4',6'-ditert-butyl-[1,1':3',1”-terphenyl]-2'-yl-2,2”,3,3”,4,4”,5,5”,6,6”-d10)-2,3-dihydro-1H-benzo[d]imidazol-1-yl)phenol was synthesized in the same manner as intermediate A.

[0356] For C 58 H 44 D 10 HRMS of N4O[M]+: Calculated value: 833, Found value: 832

[0357] (4) Synthesis of Compound 2

[0358] The synthesized intermediate B (1 eq), sodium acetate (3.0 eq), and dichloro(1,5-cyclooctadiene)platinum(II))(Pt(COD)Cl2)(1.1 eq) were suspended in a 1,4-dioxane solvent. The reaction mixture was heated to 120 °C and stirred for 12 hours. After the reaction was complete, the solvent was removed under reduced pressure. The product was purified by column chromatography to obtain compound 2 in 37% yield.

[0359] For C 58 H 41 D 10 HRMS of N4OPt[M]+: Calculated value: 1025, Found value: 1024

[0360] Elemental analysis of the calculated values: C, 67.95; H, 6.00; N, 5.46; O, 1.56; Pt, 19.03

[0361] Synthesis Example 3: Synthesis of Compound 6

[0362] Reaction diagram 3

[0363]

[0364] (5) Synthesis of intermediate C

[0365] Except that 3-(tert-butyl)-5-(3-(4,4”-di-tert-butyl-[1,1':3',1”-terphenyl]-2'-yl-2,2”,3,3”,5,5”,6,6”-d8)-2,3-dihydro-1H-benzo[d]imidazol-1-yl)phenol was used instead of 3-(tert-butyl)-5-(3-(4',6'-di-tert-butyl-[1,1':3',1”-terphenyl]-2'-yl-2,2”,3,3”,4,4”,5,5”,6,6”-d10)-2,3-dihydro-1H-benzo[d]imidazol-1-yl)phenol was synthesized in the same manner as intermediate A.

[0366] For C 64 H 58 HRMS of D8N4O[M]+: Calculated value: 915, Found value: 914

[0367] (6) Synthesis of Compound 6

[0368] The synthesized intermediate C (1 eq), sodium acetate (3.0 eq), and dichloro(1,5-cyclooctadiene)platinum(II))(Pt(COD)Cl2)(1.1 eq) were suspended in a 1,4-dioxane solvent. The reaction mixture was heated to 120 °C and stirred for 12 hours. After the reaction was complete, the solvent was removed under reduced pressure. The product was purified by column chromatography to obtain compound 6 in 41% yield.

[0369] For C 64 H 55 HRMS of D8N4OPt[M]+: Calculated value: 1107, Found value: 1106

[0370] Elemental analysis of the calculated values: C, 69.42; H, 6.46; N, 5.06; O, 1.44; Pt, 17.62

[0371] Synthesis Example 4: Synthesis of Compounds 1-3

[0372] Reaction diagram 4

[0373]

[0374] (7) Synthesis of compounds 1-3

[0375] Pd(dba)3 (0.03 eq), (t-Bu)3P (0.06 eq), and toluene (0.1 M 1 eq) were added to a flask containing 2-(5-bromo-[1,1'-biphenyl]-3-yl)dibenzo[b,d]furan (1 eq) and (3-(9H-carbazole-9-yl)phenyl)boronic acid (1.2 eq), and the mixture was refluxed and stirred for 8 hours. The reaction mixture was cooled to room temperature, extracted with dichloromethane, and washed with distilled water. The reaction mixture was dried over anhydrous MgSO4, distilled under reduced pressure, and the residue was separated by column chromatography to obtain compounds 1-3 (yield: 81.7%).

[0376] For C 42 H 27 HRMS for NO[M]+: Calculated value: 561, Found value: 560

[0377] Elemental analysis of the calculated values: C, 89.81; H, 4.85; N, 2.49; O, 2.85

[0378] Synthesis Example 5: Synthesis of Compound 2-13

[0379] Reaction diagram 5

[0380]

[0381] (8) Synthesis of compound 2-13

[0382] 9-(3'-bromo-[1,1'-biphenyl]-3-yl)-9H-carbazole (1 eq) and 9H-carbazole-3-onitrile (1.2 eq) were dissolved in 500 mL of toluene. Pd(dba)3 (0.03 eq), (t-Bu)3P (0.06 eq), and toluene (0.1 M 1 eq) were added, and the mixture was refluxed and stirred for 8 hours. The reaction mixture was cooled to room temperature, extracted with dichloromethane, and washed with distilled water. The reaction mixture was dried over anhydrous MgSO4, distilled under reduced pressure, and the residue was separated by column chromatography to obtain compound 2-13 (yield: 81.7%).

[0383] For C 37 H 23 HRMS for N3[M]+: Calculated value: 509, Found value: 508

[0384] Elemental analysis of the calculated values: C, 87.20; H, 4.55; N, 8.25

[0385] Synthesis Example 6: Synthesis of Compounds 2-16

[0386] Reaction diagram 6

[0387]

[0388] (9) Synthesis of intermediate D

[0389] Pd(dba)3 (0.03 eq), (t-Bu)3P (0.06 eq), and toluene (0.1 M 1 eq) were added to a flask containing 9H-carbazole (1 eq) and 2,4-dichloro-6-phenyl-1,3,5-triazine (0.9 eq), and the mixture was refluxed and stirred for 8 hours. The reaction mixture was cooled to room temperature, extracted with dichloromethane, and washed with distilled water. The reaction mixture was dried over anhydrous MgSO4, distilled under reduced pressure, and the residue was separated by column chromatography to obtain intermediate D (yield: 88.44%).

[0390] For C 21 H 13 HRMS of ClN4[M]+: Calculated value: 356, Found value: 355

[0391] (10) Synthesis of compound 2-16

[0392] 9-(4-chloro-6-phenyl-1,3,5-triazin-2-yl)-9H-carbazole (1 eq) and (3-(triphenylsilyl)phenyl)boronic acid (1.2 eq) were dissolved in 500 mL of toluene. Pd(PPh3)4 (0.02 eq) was added. Furthermore, 400 mL of toluene and 70 mL of a saturated solution of 2 M K2CO3 were added, and the mixture was refluxed and stirred for 5 hours. After the reaction was complete, the product was washed and extracted with 400 mL of dichloromethane and 150 mL of distilled water to remove the solvent. The resulting solid was purified by column chromatography to obtain the desired compound 2-16 (yield: 77.6%).

[0393] For C 45 H 32 HRMS of N4Si[M]+: Calculated value: 656, Found value: 656

[0394] Elemental analysis of the calculated values: C, 82.28; H, 4.91; N, 8.53; Si, 4.28

[0395] 2. Calculation of energy levels in organometallic compounds

[0396] The first compound, second compound (or first host), and third compound (or second host) used in each emitting layer of the example and comparative organic electroluminescent devices are listed in Table 1.

[0397] Table 1

[0398] emission layer First compound Second compound Third compound Example 1 1 1-3 2-16 Example 2 2 1-3 2-16 Example 3 6 1-3 2-16 Example 4 1 1-3 2-13 Comparison Example 1 C1 1-3 2-16

[0399] Example of the first compound

[0400]

[0401] Example of compound 2

[0402]

[0403] Example of compound three

[0404]

[0405] Comparative Example: Compound 1

[0406]

[0407] Table 2

[0408] compound <![CDATA[ 3 MLCT (ratio) T1 energy level (kcal / mol) Compound 1 11.2％ 2.70 Compound 2 11.0％ 2.69 Compound 6 12.0％ 2.66 Comparative example compound C1 10.3％ 2.61

[0409] Table 2 above shows the MLCT ratios and T1 energy levels for the example and comparative example compounds. As used herein, the term "MLCT ratio" is used in conjunction with the comparative example compounds. 3 "MLCT ratio" refers to the charge transfer from triplet metal to ligand (MLCT ratio). 3 The MLCT ratio shows the relative ratio based on the case where 100% charge is transferred from the metal atom to the ligand. Referring to the results in Table 2, compounds 1, 2, and 6 are used as example compounds. 3 The MLCT value is 11% or greater, which is higher than that of the comparative example compound C1. 3 MLCT value (10.3%). Therefore, organometallic compounds manufactured according to some exemplary embodiments of the invention can exhibit high... 3 The MLCT ratio, thus when organometallic compounds are used as emitter layer materials, helps to improve the efficiency of organic electroluminescent devices.

[0410] In addition, the T1 energy levels of example compounds 1, 2 and 6 are 2.66 kcal / mol or greater, which is higher than the T1 energy level of comparative example compound C1 (2.61 kcal / mol).

[0411] Therefore, although we do not wish to be bound by theory, the example compounds contain substituents that introduce steric hindrance to reduce intermolecular interactions and exhibit higher metal-ligand binding forces and molecular stability compared to the comparative example compounds. It was found that when the example compounds are applied to organic electroluminescent devices, device lifetime can be improved.

[0412] 3. Fabrication and evaluation of organic electroluminescent devices, including organometallic compounds.

[0413] Manufacturing of organic electroluminescent devices

[0414] The following describes the fabrication of an organic electroluminescent device comprising an organometallic compound in the emitting layer, constructed according to the principles of the invention and some exemplary embodiments.

[0415] There will be approximately on the glass substrate The ITO pattern was patterned to a thickness of approximately [thickness value missing], washed with ultrapure water, and treated with UV ozone for approximately 10 minutes. Then, compound HT1 was deposited on a glass substrate to a thickness of approximately [thickness value missing]. The thickness was such that compound 3 was deposited on the glass substrate to approximately [a certain thickness]. The thickness is increased to form a hole transport region. Next, when forming the emitter layer, an example or comparative example organometallic compound, a first host, and a second host are co-deposited at a weight ratio of 7:3:1 to form... Thick layers. That is, each emission layer formed by co-deposition is deposited by mixing compounds 1, 1-3, and 2-16 in Example 1, by mixing compounds 2, 1-3, and 2-16 in Example 2, by mixing compounds 6, 1-3, and 2-16 in Example 3, and by mixing compounds 1, 1-3, and 2-13 in Example 4. An emission layer formed by co-deposition is also deposited by mixing compound C1, 1-3, and 2-16 in the comparative example.

[0416] After forming the emission layer, compound ET1 is used to form... A thick layer. Then, compounds ET2 and Liq were co-deposited at a 1:1 weight ratio to form... Thick layers, formed with Liq A thick layer is formed to create an electron transport region. Then, magnesium and aluminum are co-deposited at a weight ratio of 1:9 to form... Thick second electrode.

[0417] In the example, a vacuum deposition apparatus is used to form the hole transport region, the emitter layer, the electron transport region, and the second electrode.

[0418] Compounds used in organic electroluminescent devices

[0419]

[0420] Evaluation of the characteristics of organic electroluminescent devices

[0421] The evaluation results of the organic electroluminescent devices of Examples 1 to 4 and Comparative Example 1 are listed in Table 3.

[0422] Table 3

[0423] Device characteristics Drive voltage (V) life(%) Example 1 4.3 130 Example 2 4.3 136 Example 3 4.4 133 Example 4 4.2 125 Comparison Example 1 4.5 100

[0424] Table 3 lists the lifetimes and driving voltages of the fabricated organic electroluminescent devices for comparison. The lifetimes of the devices in Examples 1 through 4 are described when the lifetime of the device in Comparative Example 1 is considered to be 100%. Referring to the results in Table 3, compared to the organic electroluminescent device in Comparative Example 1, the organic electroluminescent devices in Examples 1 through 4 exhibit significantly and unexpectedly lower driving voltages and significantly and unexpectedly improved lifetimes.

[0425] Referring to the evaluation results of the example compounds and examples of organic electroluminescent devices, although not wishing to be bound by theory, the organometallic compounds according to some exemplary embodiments include substituents that introduce steric hindrance, thereby reducing intermolecular interactions and increasing molecular stability. Furthermore, when the organometallic compounds of some exemplary embodiments are applied to the emitter layer, the exciton quenching mechanism is suppressed in the emitter layer; therefore, significant and unexpectedly high efficiency and significant and unexpectedly long lifetime characteristics of the organic electroluminescent devices can be obtained.

[0426] Organic electroluminescent devices constructed according to the principles and exemplary embodiments of the invention can have low driving voltage and improved lifetime characteristics. Organometallic compounds can be applied to the emitter layer of organic electroluminescent devices to help reduce the driving voltage and improve the lifetime of organic electroluminescent devices.

[0427] Although certain exemplary embodiments and implementations have been described herein, other embodiments and modifications will be apparent from this description. Therefore, the inventive concept is not limited to such embodiments, but is limited to the broader scope of the appended claims and various obvious modifications and equivalent arrangements that will be apparent to those skilled in the art.

Claims

1. An organic electroluminescent device, the organic electroluminescent device comprising: First electrode; The second electrode faces the first electrode; as well as Multiple organic layers are disposed between the first electrode and the second electrode. The emission layer among the plurality of organic layers includes a first compound represented by Formula 1, a second compound represented by Formula 2, and a third compound represented by Formula 3: Formula 1 In Equation 1, M is Pt, Au, Pd, Cu, or Ag. Y is either O or S. Ar1, Ar2, and Ar3 are each independently an aromatic hydrocarbon ring with 6 to 30 cyclic carbon atoms, either substituted or unsubstituted, or an aromatic heterocycle with 2 to 30 cyclic carbon atoms, and Ar1 includes an aryl group, a substituted or unsubstituted alkyl group, a cyano group, and a substituted or unsubstituted aryl group as a substituent. L1 is either a direct-connect key or N. L2 is a direct-connect key. L3 is a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms. a is 0 or 1. b is an integer between 0 and 2. R1 is a direct bond, a hydrogen atom, a deuterium atom, an aryl group with 6 to 30 cyclic carbon atoms (substituted or unsubstituted), or a heteroaryl group with 3 to 30 cyclic carbon atoms (substituted or unsubstituted), and optionally, it is bonded to an adjacent group to form a ring. m is an integer from 0 to 4. Formula 2 In Equation 2, Ar can be a substituted or unsubstituted silyl group, a substituted or unsubstituted aryl group with 6 to 30 cyclic carbon atoms, or a substituted or unsubstituted heteroaryl group with 3 to 30 cyclic carbon atoms. L is a linearly bonded, 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. R 21 and R 22 Each group is independently 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 optionally, it is incorporated into an adjacent group to form a ring. n1 and n2 are both independent integers from 0 to 4. Formula 3 In Equation 3, R 31 R 32 R 33 R 34 R 35 and R 36 Each of the groups is independently composed of a hydrogen atom, a deuterium atom, a cyano group, a substituted silyl group, 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 optionally, is incorporated into an adjacent group to form a ring. Z 11 Z 12 and Z 13 Each of them is independently C or N.

2. The organic electroluminescent device according to claim 1, wherein, The first compound is represented by formula 1-1a or formula 1-1b: Formula 1-1a Formula 1-1b Among them, in equations 1-1a and 1-1b, R5 and R6 are each independently a hydrogen atom, a deuterium atom, 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 optionally, are incorporated into adjacent groups to form a ring. o1 is an integer from 0 to 4. o2 is an integer from 0 to 3, and In Equations 1-1a and 1-1b, M, Ar1 to Ar3, Y, L3 and b independently have the same meaning as defined in Equation 1.

3. The organic electroluminescent device according to claim 1, wherein, The first compound is represented by formula 1-2a or formula 1-2b: Formula 1-2a Formula 1-2b Among them, in equations 1-2a and 1-2b, R7 is a hydrogen atom, a deuterium atom, an aryl group with 6 to 30 cyclic carbon atoms (substituted or unsubstituted), or a heteroaryl group with 3 to 30 cyclic carbon atoms (substituted or unsubstituted), and optionally, it is bonded to an adjacent group to form a ring. p is an integer from 0 to 4. Ar4 and Ar5 are each independently represented by equations S1 to S3: Among them, in equations S1 to S3, R a R b and R c Each of the groups is independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a cyano group, or a substituted or unsubstituted aryl group having 6 to 30 cyclic carbon atoms, and optionally, is incorporated into an adjacent group to form a ring. In Equations 1-2a and 1-2b, M, Y, Ar2, Ar3, L1 to L3, a, b, R1 and m independently have the same meaning as defined in Equation 1.

4. The organic electroluminescent device according to claim 1, wherein, The first compound is represented by formula 1-3a or formula 1-3b: Formula 1-3a Formula 1-3b Among them, in equations 1-3a and 1-3b, R8 and R9 are each independently a hydrogen atom, a deuterium atom, 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 optionally, are incorporated into adjacent groups to form a ring. q1 and q2 are each independent integers from 0 to 3, and In Equations 1-3a and 1-3b, M, Y, Ar1 and Ar3, L1 to L3, a, b, R1 and m independently have the same meaning as defined in Equation 1.

5. The organic electroluminescent device according to claim 1, wherein, The first compound is represented by formula 1-4a or formula 1-4b: Formula 1-4a Formula 1-4b Among them, in equations 1-4a and 1-4b, R 10 and R 11 Each group is independently composed of a hydrogen atom, a deuterium atom, 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 optionally, is attached to an adjacent group to form a ring. r1 is an integer from 0 to 3. r2 is an integer from 0 to 2, and In Equations 1-4a and 1-4b, M, Y, Ar1, Ar2, L1 to L3, a, b, R1 and m independently have the same meaning as defined in Equation 1.

6. The organic electroluminescent device according to claim 1, wherein, The first compound is represented by formulas 1-5: Formula 1-5 Among them, in equations 1-5, Y, Ar1 to Ar3, L1 to L3, a, b, R1 and m independently have the same meaning as defined in Equation 1.

7. The organic electroluminescent device according to claim 1, wherein, The first compound is represented by formulas 1-6: Formula 1-6 Among them, in equations 1-6, M, Ar1 to Ar3, L1 to L3, a, b, R1 and m independently have the same meaning as defined in Equation 1.

8. The organic electroluminescent device according to claim 1, wherein, The first compound is represented by formula 1-7a or formula 1-7b: Formula 1-7a Formula 1-7b Among them, in equations 1-7a and 1-7b, R5 and R6 are each independently a hydrogen atom, a deuterium atom, 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 optionally, are incorporated into adjacent groups to form a ring. o1 is an integer from 0 to 4. o2 is an integer from 0 to 3, and R 10 and R 11 Each group is independently composed of a hydrogen atom, a deuterium atom, 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 optionally, is attached to an adjacent group to form a ring. r1 is an integer from 0 to 3. r2 is an integer from 0 to 2, and In Equations 1-7a and 1-7b, M, Ar1, Ar2, Y, L3, and b independently have the same meaning as defined in Equation 1.

9. The organic electroluminescent device according to claim 1, wherein, The plurality of organic layers include a hole transport region, an emission layer, and an electron transport region.

10. The organic electroluminescent device according to claim 9, wherein, The emitting layer is configured to emit phosphorescence.

11. The organic electroluminescent device according to claim 1, wherein, The first compound comprises at least one of the compounds represented by group 1 of compounds below, the second compound comprises at least one of the compounds represented by group H1 of compounds below, and the third compound comprises at least one of the compounds represented by group H2 of compounds below: Compound group 1 Compound group H1 Compound group H2

Images