Organic electroluminescent element

Abstract

An organic electroluminescent element is disclosed. The organic electroluminescent element in one embodiment includes: a first electrode; a second electrode disposed on the first electrode; and a first light-emitting layer and a second light-emitting layer disposed between the first electrode and the second electrode, wherein the first light-emitting layer includes a first host and a first dopant containing an anthracene-based compound, the second light-emitting layer includes a second host represented by the following chemical formula H-1 and a second dopant containing an organometallic compound, and the first light-emitting layer and the second light-emitting layer are disposed adjacent to each other, so that high luminous efficiency and long-life characteristics can be exhibited. [Chemical formula H-1]

Description

Technical Field

[0001] The present invention relates to an organic electroluminescent element, and more particularly, to an organic electroluminescent element including a plurality of light-emitting layers. Background Art

[0002] Recently, as an image display device, the development of an Organic Electroluminescence Display has been vigorously carried out. Different from a liquid crystal display device and the like, an organic electroluminescent display device is a so-called self-luminous display device that realizes display by causing holes and electrons injected from a first electrode and a second electrode to recombine in a light-emitting layer, thereby causing a light-emitting material including an organic compound to emit light in the light-emitting layer.

[0003] When applying an organic electroluminescent element to a display device, it is required to lower the driving voltage, increase the luminous efficiency, and extend the lifespan of the organic electroluminescent element, and there is a continuous need to develop materials for organic electroluminescent elements that can stably achieve these.

[0004] In particular, recently, in order to realize a high-luminous-efficiency organic electroluminescent element, a technology for a double light-emitting layer including a first light-emitting layer and a second light-emitting layer using a double light-emitting layer has been developed, and a development for a combination of materials for each light-emitting layer has been carried out. Summary of the Invention

[0005] An object of the present invention is to provide an organic electroluminescent element that exhibits excellent lifespan characteristics and excellent luminous efficiency.

[0006] An organic electroluminescent element according to an embodiment of the present invention includes: a first electrode; a second electrode disposed on the first electrode; and a first light-emitting layer and a second light-emitting layer disposed between the first electrode and the second electrode, wherein the first light-emitting layer includes a first host and a first dopant including an anthracene-based compound, the second light-emitting layer includes a second host represented by the following Chemical Formula H-1 and a second dopant different from the first dopant and including an organometallic compound, and the first light-emitting layer and the second light-emitting layer are adjacent to each other.

[0007] [Chemical Formula H-1]

[0008]

[0009] In the chemical formula H-1, Ar1 to Ar3 are each independently a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms, L is a direct linkage, a substituted or unsubstituted silyl group, a substituted or unsubstituted boronic group, a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms, a substituted or unsubstituted arylene group having 6 to 60 ring carbon atoms or a substituted or unsubstituted heteroarylene group having 2 to 60 ring carbon atoms, R1 and R2 are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted phosphine oxide group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms, or combine with adjacent groups to form a ring, and a to c are each independently an integer of 0 or more and 2 or less.

[0010] In one embodiment of the present invention, the second host may be represented by the following chemical formula H-1a.

[0011] [Chemical formula H-1a]

[0012]

[0013] In the chemical formula H-1a, Ar3, R1, R2, L, and a to c are the same as those defined in the chemical formula H-1.

[0014] In one embodiment of the present invention, the first dopant may be represented by the following chemical formula D-1.

[0015] [Chemical formula D-1]

[0016]

[0017] In the chemical formula D-1, R 11 to R 18 are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms, L 11 and L 12Each independently is a direct linkage, a substituted or unsubstituted amino group, a substituted or unsubstituted silyl group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms, a substituted or unsubstituted arylene group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 60 ring carbon atoms, Ar 11 and Ar 12 Each independently is a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted silyl group, a substituted or unsubstituted selenium group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms, and m and n are each independently an integer of 0 to 3.

[0018] In one embodiment of the present invention, the first dopant can be represented by the following chemical formula D-1a, chemical formula D-1b, or chemical formula D-1c.

[0019] [Chemical formula D-1a]

[0020]

[0021] [Chemical formula D-1b]

[0022]

[0023] [Chemical formula D-1c]

[0024]

[0025] In the chemical formula D-1a, chemical formula D-1b, and chemical formula D-1c, Ar 11 , Ar 12 , R 11 to R 18 , m and n are the same as those defined in chemical formula D-1.

[0026] In one embodiment of the present invention, the second dopant can include iridium (Ir), platinum (Pt), palladium (Pd), or gold (Au).

[0027] In one embodiment of the present invention, the lowest triplet excitation energy level (T1 level) of the first dopant can be 2.0 eV or less.

[0028] In one embodiment of the present invention, the thickness of the first light-emitting layer can be 1 nm or more and 10 nm or less.

[0029] In an embodiment of the present invention, the second light-emitting layer may be disposed between the first light-emitting layer and the first electrode.

[0030] In an embodiment of the present invention, the first light-emitting layer may be in contact with the second light-emitting layer.

[0031] In an embodiment of the present invention, the first dopant may include at least one of the compounds represented in the following Compound Group 1.

[0032] [Compound Group 1]

[0033]

[0034]

[0035]

[0036]

[0037] In an embodiment of the present invention, the second host may include at least one of the compounds represented in the following Compound Group 2.

[0038] [Compound Group 2]

[0039]

[0040]

[0041]

[0042]

[0043] An organic electroluminescent element according to an embodiment of the present invention includes: a first electrode; a second electrode disposed on the first electrode; and a first light-emitting layer and a second light-emitting layer disposed between the first electrode and the second electrode, wherein the first light-emitting layer includes a first host and a first dopant represented by the following Chemical Formula D-1, and the second light-emitting layer includes a second host represented by the following Chemical Formula H-1 and a second dopant different from the first dopant.

[0044] [Chemical Formula D-1] [Chemical Formula H-1]

[0045]

[0046] In the Chemical Formula D-1, R 11 to R 18Each independently is a hydrogen atom, a deuterium atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms, L 11 and L 12 Each independently is a direct bond, a substituted or unsubstituted amino group, a substituted or unsubstituted silyl group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms, a substituted or unsubstituted arylene group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 60 ring carbon atoms, Ar 11 and Ar 12 Each independently is a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted silyl group, a substituted or unsubstituted seleno group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms. m and n are each independently an integer of 0 to 3. In the formula H-1, Ar1 to Ar3 are each independently a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms. L is a direct bond, a substituted or unsubstituted silyl group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms, a substituted or unsubstituted arylene group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 60 ring carbon atoms. R1 and R2 are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted phosphine oxide group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms, or combine with adjacent groups to form a ring. a to c are each independently an integer of 0 to 2.

[0047] An organic electroluminescent element of an embodiment may include two light-emitting layers and exhibit high luminous efficiency and long-life characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1a and Figure 1b are schematic cross-sectional views showing an organic electroluminescent element according to an embodiment of the present invention.

[0049] Figure 2 is a cross-sectional view schematically showing an organic electroluminescent element according to an embodiment of the present invention.

[0050] Figure 3 is a cross-sectional view schematically showing an organic electroluminescent element according to an embodiment of the present invention.

[0051] Figure 4 is a cross-sectional view schematically showing an organic electroluminescent element according to an embodiment of the present invention.

[0052] Symbol Explanation

[0053] 10: Organic electroluminescent element EL1: First electrode

[0054] EL2: Second electrode HTR: Hole transport region

[0055] EML1: First light-emitting layer EML2: Second light-emitting layer

[0056] ETR: Electron transport region Detailed Description of the Invention

[0057] The present invention can be variously modified and can have various forms. Specific embodiments are illustrated in the drawings and described in detail herein. However, it is not intended to limit the present invention to the specific disclosed forms, and it should be understood to include all modifications, equivalents, and alternatives included in the spirit and technical scope of the present invention.

[0058] In this specification, when a certain component (or region, layer, part, etc.) is referred to as being "above" another component, "connected" to another component, or "combined" with another component, it means that it can be directly disposed / connected / combined on another component, or a third component can also be disposed between them.

[0059] The same reference numerals refer to the same components. Also, for effective illustration of the technical content, in the drawings, the thickness, ratio, and size of the components are exaggerated.

[0060] "And / or" includes all combinations that can be defined by the relevant components.

[0061] The terms "first", "second", etc. may be used to describe various components, but the components should not be limited by these terms. These terms are only used for the purpose of differentiating one component from another. For example, without departing from the scope of the claims of the present invention, the first component may be named the second component, and similarly, the second component may also be named the first component. Singular expressions include plural expressions as long as they do not clearly indicate a different meaning in the context.

[0062] In addition, terms such as "below", "lower side", "above", "upper side", etc. are used to describe the relative relationship between the components shown in the drawings. These terms are relative concepts and are described based on the directions shown in the drawings.

[0063] Unless otherwise defined, all terms (including technical terms and scientific terms) used in this specification have the same meaning as those commonly understood by those skilled in the technical field to which the present invention pertains. Also, terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the related art, and are explicitly defined herein as long as they are not interpreted as ideal or overly formal meanings.

[0064] Terms such as "comprising" or "having" should be understood as intended to specify the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and not to preclude the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0065] Hereinafter, an organic electroluminescent element according to an embodiment of the present invention and a compound according to an embodiment included therein will be described with reference to the drawings.

[0066] Figure 1a 、 Figure 1b 、 Figure 2 、 Figure 3 and Figure 4 are cross-sectional views schematically showing an organic electroluminescent element according to an embodiment of the present invention. Referring to Figures 1a to 4 , in the organic electroluminescent element 10 of an embodiment, the first electrode EL1 and the second electrode EL2 are arranged opposite to each other, and a first light-emitting layer EML1 and a second light-emitting layer EML2 may be arranged between the first electrode EL1 and the second electrode EL2. In the organic electroluminescent element 10 of an embodiment, the stacking order of the first light-emitting layer EML1 and the second light-emitting layer EML2 is not limited.

[0067] For example, as Figure 1a, the second emission layer EML2 may be formed between the first emission layer EML1 and the first electrode EL1. Alternatively, as Figure 1b shown, the second emission layer EML2 may be formed between the first emission layer EML1 and the second electrode EL2. Hereinafter, in this specification, an organic electroluminescent element 10 of an embodiment in which the second emission layer EML2 is formed between the first emission layer EML1 and the first electrode EL1 will be described as a reference.

[0068] In addition, as Figures 1a to 4 shown, in one embodiment, the first emission layer EML1 and the second emission layer EML2 may be arranged adjacent to each other. Specifically, the first emission layer EML1 may be in contact with the second emission layer EML2. Hereinafter, in this specification, an organic electroluminescent element 10 in which the first emission layer EML1 is in contact with the second emission layer EML2 will be described as a reference.

[0069] An organic electroluminescent element 10 of one embodiment includes a plurality of functional layers between the first electrode EL1 and the second electrode EL2 in addition to the first emission layer EML1 and the second emission layer EML2. The plurality of functional layers may include a hole transport region HTR and an electron transport region ETR. That is, an organic electroluminescent element 10 according to one embodiment may include a first electrode EL1, a hole transport region HTR, a second emission layer EML2, a first emission layer EML1, an electron transport region ETR, and a second electrode EL2 which are stacked in sequence. And, an organic electroluminescent element 10 of one embodiment may further include a packaging layer CPL disposed on the second electrode EL2.

[0070] An organic electroluminescent element 10 of one embodiment may include a compound of one embodiment described later in the first emission layer EML1 and the second emission layer EML2 disposed between the first electrode EL1 and the second electrode EL2. However, the embodiment is not limited thereto. An organic electroluminescent element 10 of one embodiment may include a compound according to one embodiment described later in the hole transport region HTR or the electron transport region ETR which are a plurality of functional layers disposed between the first electrode EL1 and the second electrode EL2 in addition to the first emission layer EML1 and the second emission layer EML2, or may include a compound according to one embodiment described later in the packaging layer CPL disposed on the second electrode EL2.

[0071] In addition, compared with Figure 1a , Figure 2 FIG. shows a cross-sectional view of an organic electroluminescent element 10 of an embodiment in which the hole transport region HTR includes a hole injection layer HIL and a hole transport layer HTL, and the electron transport region ETR includes an electron injection layer EIL and an electron transport layer ETL. And, compared with Figure 1a , Figure 3A cross-sectional view of an organic electroluminescent element 10 according to an embodiment is shown, in which a hole transport region HTR includes a hole injection layer HIL, a hole transport layer HTL, and an electron blocking layer EBL, and an electron transport region ETR includes an electron injection layer EIL, an electron transport layer ETL, and a hole blocking layer HBL. Compared with Figure 2 , Figure 4 A cross-sectional view of an organic electroluminescent element 10 according to an embodiment is shown, which includes a packaging layer CPL disposed on a second electrode EL2.

[0072] The first electrode EL1 has conductivity. The first electrode EL1 can be formed of a metal alloy or a conductive compound. The first electrode EL1 can be an anode. Also, the first electrode EL1 can be a pixel electrode. The first electrode EL1 can be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the first electrode EL1 is a transmissive electrode, the first electrode EL1 can include a transparent metal oxide, for example, indium tin oxide (ITO: indium tin oxide), indium zinc oxide (IZO: indium zinc oxide), zinc oxide (ZnO: zinc oxide), indium tin zinc oxide (ITZO: indium tin zinc oxide), etc. When the first electrode EL1 is a semi-transmissive electrode or a reflective electrode, the first electrode EL1 can include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof (for example, a mixture of Ag and Mg). Or, it can be a multi-layer structure including a reflective film or a semi-transmissive film formed of the above substances and a transparent conductive film formed of indium tin oxide (ITO: indium tin oxide), indium zinc oxide (IZO: indium zinc oxide), zinc oxide (ZnO: zinc oxide), indium tin zinc oxide (ITZO: indium tin zinc oxide), etc. For example, the first electrode EL1 can have a three-layer structure of ITO / Ag / ITO, but is not limited thereto. The thickness of the first electrode EL1 can be about to about For example, about to about

[0073] The hole transport region HTR is provided on the first electrode EL1. The hole transport region HTR can include at least one of a hole injection layer HIL, a hole transport layer HTL, a hole buffer layer (not shown), and an electron blocking layer EBL. The thickness of the hole transport region HTR can be, for example, about to about

[0074] The hole transport region HTR may have a single-layer structure composed of a single material, a single-layer structure composed of multiple different materials, or a multi-layer structure having multiple layers composed of multiple different materials.

[0075] For example, the hole transport region HTR may have a single-layer structure of a hole injection layer HIL or a hole transport layer HTL, or may have a single-layer structure composed of a hole injection material and a hole transport material. Also, the hole transport region HTR may have a single-layer structure composed of multiple different materials, or may have a structure of a hole injection layer HIL / hole transport layer HTL, a hole injection layer HIL / hole transport layer HTL / hole buffer layer (not shown), a hole injection layer HIL / hole buffer layer (not shown), a hole transport layer HTL / hole buffer layer (not shown), or a hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL sequentially stacked from the first electrode EL1. However, the embodiments are not limited thereto.

[0076] The hole transport region HTR can be formed by various methods such as vacuum deposition method, spin coating method, casting method, LB method (Langmuir-Blodgett), inkjet printing method, laser printing method, laser thermal transfer method (LITI: Laser Induced Thermal Imaging), etc.

[0077] The hole injection layer HIL may also include, for example: phthalocyanine compounds such as copper phthalocyanine;N,N'-Diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine (DNTPD), 4,4',4"-[tris(3-methylphenyl)phenylamino]triphenylamine (m-MTDATA), 4,4'4"-Tris(N,N-diphenylamino)triphenylamine (TDATA), 4,4',4"-tris{N-(2-naphthyl)-N-phenylamino}-triphenylamine (2-TNATA), Poly(3,4-ethylenedioxythiophene) / Poly(4-styrenesulfonate) (PEDOT / PSS), Polyaniline / Dodecylbenzenesulfonic acid (PANI / DBSA), Polyaniline / Camphor sulfonicacid (PANI / CSA), Polyaniline / Poly(4-styrenesulfonate) (PANI / PSS), N,N'-di(naphthalene-l-yl)-N,N'-diphenyl-benzidine (NPB), Triphenylamine-containing polyether ketone (TPAPEK), 4-Isopropyl-4'-methyldiphenyliodonium [Tetrakis(pentafluorophenyl)borate], dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), etc.;

[0078] The hole transport layer HTL may also include, for example: carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, fluorene derivatives, triphenylamine derivatives such as N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA), N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB), 4,4′-Cyclohexylidene bis[N,N-bis(4-methylphenyl)benzenamine] (TAPC), 4,4'-Bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl (HMTPD), 1,3-bis(N-carbazolyl)benzene (mCP), etc.

[0079] The thickness of the hole transport region HTR can be about to about For example, about to about The thickness of the hole injection layer HIL can be, for example, about to about The thickness of the hole transport layer HTL can be about to about For example, the thickness of the electron blocking layer EBL can be about to about When the thicknesses of the hole transport region HTR, the hole injection layer HIL, the hole transport layer HTL, and the electron blocking layer EBL satisfy the ranges described above, relatively satisfactory hole transport characteristics can be obtained without substantially increasing the driving voltage.

[0080] In addition to the substances mentioned above, in order to improve the conductivity, the hole transport region HTR may further include a charge generation substance. The charge generation substance may be uniformly or non-uniformly dispersed within the hole transport region HTR. The charge generation substance may be, for example, a p-dopant. The p-dopant may be one of a quinone derivative, a metal oxide, and a compound containing a cyano group, but is not limited thereto. For example, non-limiting examples of the p-dopant may include quinone derivatives such as tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-7,7’,8,8’-tetracyanoquinodimethane (F4-TCNQ), metal oxides such as tungsten oxide and molybdenum oxide, and inorganic metal compounds such as CuI and RbI, but are not limited thereto.

[0081] As described above, in addition to the hole injection layer HIL and the hole transport layer HTL, the hole transport region HTR may further include at least one of a hole buffer layer (not shown) and an electron blocking layer (EBL). The hole buffer layer (not shown) may compensate for the resonance distance according to the wavelength of the light emitted from the light emitting layers EML1 and EML2 to improve the light emission efficiency. The substance included in the hole buffer layer (not shown) may be a substance that can be included in the hole transport region HTR. The electron blocking layer EBL is a layer that serves to prevent electrons from being injected from the electron transport region ETR into the hole transport region HTR.

[0082] The first light emitting layer EML1 and the second light emitting layer EML2 are provided on the hole transport region HTR. The first light emitting layer EML1 and the second light emitting layer EML2 may have a single layer structure composed of a single substance, a single layer structure composed of a plurality of different substances, or a multi-layer structure having a plurality of layers composed of a plurality of different substances.

[0083] In the organic electroluminescent element 10 of an embodiment, the first light emitting layer EML1 may include a first host and a first dopant. The first dopant may be a fluorescent dopant. The second light emitting layer EML2 may include a second host and a second dopant. The second dopant may be a phosphorescent dopant.

[0084] In addition, in this specification, "substituted or unsubstituted" may mean substituted or unsubstituted by one or more substituents selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amino group, a silyl group, an oxy group, a thio group, a sulfite group, a sulfonyl group, a carbonyl group, a boron group, a phosphinyl group, a phosphinothioyl group, an alkyl group, an alkenyl group, an alkoxy group, a hydrocarbon ring group, an aryl group, and a heterocyclic group. Moreover, each of the substituents exemplified above may be a substituted or unsubstituted substituent. For example, a biphenyl group may be interpreted as an aryl group or as a phenyl group substituted by a phenyl group.

[0085] In this specification, "combining with adjacent groups to form a ring" may mean combining with adjacent groups to form a substituted or unsubstituted hydrocarbon ring or a substituted or unsubstituted heterocyclic ring. The hydrocarbon ring includes an aliphatic hydrocarbon ring and an aromatic hydrocarbon ring. The heterocyclic ring includes an aliphatic heterocyclic ring and an aromatic heterocyclic ring. The ring formed by combining with adjacent groups may be a monocyclic or polycyclic ring. Moreover, the ring formed by combining with each other may be connected to other rings to form a helical structure.

[0086] In this specification, "adjacent groups" may mean a substituent substituting an atom directly connected to the atom substituted by the corresponding substituent, another substituent substituting the atom substituted by the corresponding substituent, or a substituent closest to the corresponding substituent in the steric structure. For example, in 1,2-dimethylbenzene, the two methyl groups may be interpreted as "adjacent groups", and in 1,1-diethylcyclopentane, the two ethyl groups may be interpreted as "adjacent groups" to each other.

[0087] In this specification, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0088] In this specification, the alkyl group may be linear, branched or cyclic. The number of carbon atoms in the alkyl group is 1 or more and 50 or less, 1 or more and 30 or less, 1 or more and 20 or less, 1 or more and 10 or less, or 1 or more and 6 or less. Examples of the alkyl group may include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyl octyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, n-heneicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, and n-triacontyl, etc., but are not limited thereto.

[0089] In this specification, the alkenyl group represents a hydrocarbon group including one or more carbon-carbon double bonds in the middle or at the end of an alkyl group having 2 or more carbon atoms. The alkenyl group may be linear or branched. Although the number of carbon atoms is not particularly limited, it is 2 or more and 30 or less, 2 or more and 20 or less, or 2 or more and 10 or less. Examples of the alkenyl group include vinyl, 1-butenyl, 1-pentenyl, 1,3-butadienyl, styryl, styrylethylene, etc., but are not limited thereto.

[0090] In this specification, the alkynyl group represents a hydrocarbon group including one or more carbon-carbon triple bonds in the middle or at the end of an alkyl group having 2 or more carbon atoms. The alkynyl group may be linear or branched. Although the number of carbon atoms is not particularly limited, it is 2 or more and 30 or less, 2 or more and 20 or less, or 2 or more and 10 or less. Specific examples of the alkynyl group may include ethynyl, propynyl, etc., but are not limited thereto.

[0091] In this specification, a hydrocarbon ring group may 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 ring-forming carbon atoms of the hydrocarbon ring group may be 5 or more and 60 or less, 5 or more and 30 or less, or 5 or more and 20 or less.

[0092] In this specification, an aryl group represents any functional group or substituent derived from an aromatic hydrocarbon ring. The aryl group may be a monocyclic aryl group or a polycyclic aryl group. The number of ring-forming carbon atoms of the aryl group may be 6 or more and 30 or less, 6 or more and 20 or less, or 6 or more and 15 or less. Examples of the aryl group may include a phenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group, a phenanthryl group, a biphenyl group, a terphenyl group, a quaterphenyl group, a quinquephenyl group, a sexiphenyl group, a triphenylene group, a pyrenyl group, a benzo[a]pyrenyl group, and the like, but are not limited thereto.

[0093] In this specification, a heterocyclic group represents any functional group or substituent derived from a ring including one or more heteroatoms selected from B, O, N, P, Si, and S. The heterocyclic group includes an aliphatic heterocyclic group and an aromatic heterocyclic group. The aromatic heterocyclic group may be a heteroaryl group. The aliphatic heterocycle and the aromatic heterocycle may be monocyclic or polycyclic.

[0094] In the case where the heterocyclic group includes two or more heteroatoms, the two or more heteroatoms may be the same as each other or different from each other. The number of ring-forming carbon atoms of the heterocyclic group may be 2 or more and 30 or less, 2 or more and 20 or less, or 2 or more and 10 or less.

[0095] In this specification, examples of the aliphatic heterocyclic group may include an oxiranyl group, a thiiranyl group, a pyrrolidinyl group, a piperidinyl group, a tetrahydrofuranyl group, a tetrahydrothienyl group, a thiane group, a tetrahydropyranyl group, a 1,4-dioxanyl group, and the like, but are not limited thereto.

[0096] In this specification, examples of the heteroaryl group include a thienyl group, a furyl group, a pyrrolyl group, an imidazolyl group, a triazolyl group, a pyridyl group, a bipyridyl group, a pyrimidinyl group, a triazinyl group, an acridinyl group, a pyridazinyl group, a pyrazinyl group, a quinolinyl group, a quinazolinyl group, a quinoxalinyl group, a phenoxazinyl group, a phthalazinyl group, a pyridopyrimidinyl group, a pyridopyrazinyl group, a pyrazinopyrazinyl group, an isoquinolinyl group, an indolyl group, a carbazolyl group, an N-arylcarbazolyl group, an N-heteroarylcarbazolyl group, an N-alkylcarbazolyl group, a benzoxazolyl group, a benzimidazolyl group, a benzothiazolyl group, a benzocarbazolyl group, a benzothienyl group, a dibenzothienyl group, a thienothienyl group, a benzofuranyl group, a phenanthrolinyl group, a thiazolyl group, an isoxazolyl group, an oxazolyl group, an oxadiazolyl group, a thiadiazolyl group, a phenothiazinyl group, a dibenzosilole group, and a dibenzofuranyl group, and the like, but are not limited thereto.

[0097] In this specification, in addition to being a divalent group, an arylene group may be described in accordance with the description of the aforementioned aryl group. In addition to being a divalent group, a heteroarylene group may be described in accordance with the description of the aforementioned heteroaryl group.

[0098] In this specification, silyl groups include alkylsilyl groups and arylsilyl groups. Examples of silyl groups include, but are not limited to, trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, etc.

[0099] In this specification, boranyl groups include alkylboranyl groups and arylboranyl groups. Examples of boranyl groups include, but are not limited to, trimethylboranyl, triethylboranyl, tert-butyldimethylboranyl, triphenylboranyl, diphenylboranyl, phenylboranyl, etc.

[0100] In this specification, although the number of carbon atoms of the amino group is not particularly limited, it may be 1 or more and 30 or less. The amino group may include an alkylamino group, an arylamino group, or a heteroarylamino group. Examples of amino groups include, but are not limited to, methylamino, dimethylamino, anilino, diphenylamino, naphthylamino, 9-methyl-anthrylamino, triphenylamino, etc.

[0101] In this specification, oxy groups may include alkoxy groups and aryloxy groups. The alkoxy group may be a straight-chain, branched-chain, or cyclic chain. Although the number of carbon atoms of the alkoxy group is not particularly limited, for example, it may be 1 or more and 20 or less, or 1 or more and 10 or less. Examples of oxy groups include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, butoxy, pentyloxy, hexyloxy, octyloxy, nonyloxy, decyloxy, benzyloxy, etc.

[0102] In this specification, the alkyl group in alkylthio, alkylthioxy, alkaryl, alkylamino, alkylboranyl, and alkylsilyl is the same as the examples of the aforementioned alkyl group.

[0103] In this specification, the aryl group in aryloxy, arylthio, arylthioxy, arylamino, arylboranyl, arylsilyl, arylseleno, and aralkyl is the same as the examples of the aforementioned aryl group.

[0104] In this specification, a direct linkage may represent a single bond.

[0105] In addition, in this specification, or represents the position of connection.

[0106] The first host of the first light-emitting layer EML1 of the organic electroluminescent element 10 according to an embodiment may be any common material known in the art without limitation as the host material. For example, it may also include at least one of bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO), 4,4'-bis(carbazol-9-yl)biphenyl (CBP), 1,3-bis(carbazol-9-yl)benzene (mCP), 2,8-bis(diphenylphosphoryl)dibenzo[b,d]furan (PPF), 4,4',4”-tris(carbazol-9-yl)-triphenylamine (TCTA), 1,3,5-tris(1-phenyl-1H-benzo[d]imidazole-2-yl)benzene (TPBi), 1,3-di(9H-carbazol-9-yl)benzene, 3-(3-(9H-carbazol-9-yl)phenyl)benzofuro[2,3-b]pyridine, and 5-(3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)-3,9-diphenyl-9H-carbazole.However, it is not limited thereto. For example, as the host material, it may further include tris(8-hydroxyquinolino)aluminum (Alq3), poly(n-vinylcabazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN), 3-tert-butyl-9,10-di(naphth-2-yl)anthracene (TBADN), distyrylarylene (DSA), 4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl (CDBP), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), hexaphenylcyclotriphosphazene (CP1), 1,4-bis(triphenylsilyl)benzene (UGH2), hexaphenylcyclotrisiloxane (DPSiO3), octaphenylcyclotetra siloxane (DPSiO4), etc.

[0107] In the organic electroluminescent element 10 in one embodiment, the first light-emitting layer EML1 may include an anthracene-based compound as the first dopant. Specifically, the first dopant may include a compound represented by the following chemical formula D-1.

[0108] [Chemical formula D-1]

[0109]

[0110] In Chemical formula D-1, R 11 to R 18 may each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms. For example, R 11 to R 18It may be a hydrogen atom, a methyl group, an isopropyl group, a tert-butyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted phenyl group, a naphthyl group, etc., but the examples are not limited thereto.

[0111] L 11 and L 12 may each independently be a direct linkage, a substituted or unsubstituted amino group, a substituted or unsubstituted silyl group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkylene group having 1 or more and 30 or less carbon atoms, a substituted or unsubstituted arylene group having 6 or more and 60 or less ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 or more and 60 or less ring carbon atoms. For example, L 11 and L 12 may be a substituted amino group, a substituted or unsubstituted phenyl group, a substituted boron group, or a substituted silyl group. Specifically, L 11 and L 12 may be a carbazolyl group. However, the examples are not limited thereto.

[0112] Ar 11 and Ar 12 may each independently be a substituted or unsubstituted alkenyl group having 2 or more and 30 or less carbon atoms, a substituted or unsubstituted silyl group, a substituted or unsubstituted selenium group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group having 6 or more and 60 or less ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 or more and 60 or less ring carbon atoms. Specifically, the aryl group may be a substituted or unsubstituted phenyl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted arylsilyl group, a substituted or unsubstituted arylamino group, and a substituted or unsubstituted arylselenium group. Specifically, the heteroaryl group may be a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted dibenzothiophenyl group, or a substituted or unsubstituted dibenzofuranyl group. However, the examples are not limited thereto.

[0113] m and n may each independently be an integer of 0 or more and 3 or less. For example, m and n may each independently be 0, 1, or 2. In addition, in the case where m and n are each an integer of 2 or more, multiple Ar 11 and multiple Ar 12 may all be the same or at least one may be different.

[0114] The first dopant represented by Chemical Formula D-1 may be represented by one of the following Chemical Formulas D-1a to D-1c.

[0115] [Chemical Formula D-1a]

[0116]

[0117] [Chemical Formula D-1b]

[0118]

[0119] [Chemical Formula D-1c]

[0120]

[0121] In Chemical Formulas D-1a to D-1c, regarding R 11 to R 18 , Ar 11 and Ar 12 , the descriptions of m and n can be applied the same as the definitions in Chemical Formula D-1.

[0122] In the organic electroluminescent element 10 of an embodiment, the second light-emitting layer EML2 may include a compound represented by the following Chemical Formula H-1 as the second host.

[0123] [Chemical Formula H-1]

[0124]

[0125] In Chemical Formula H-1, Ar1 to Ar3 may each independently be a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms. For example, Ar1 and Ar2 may be a substituted or unsubstituted benzene ring or a substituted or unsubstituted pyrimidine ring. However, the embodiment is not limited thereto. For example, Ar3 may be a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted arylsilyl group, or a substituted or unsubstituted triazinyl group. However, the embodiment is not limited thereto.

[0126] L can be a direct linkage, a substituted or unsubstituted silyl group, a substituted or unsubstituted boryl group, a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms, a substituted or unsubstituted arylene group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 60 ring carbon atoms. For example, the substituted or unsubstituted silyl group can be a silyl group substituted with a methyl group. The substituted or unsubstituted boryl group can be a boryl group substituted with mesitylene. The substituted or unsubstituted arylene group can be a substituted or unsubstituted phenylene group. The substituted or unsubstituted heteroarylene group can be a pyridyl group or a substituted or unsubstituted triazine. However, the examples are not limited thereto. R1 and R2 can each independently be a hydrogen atom, a deuterium atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted phosphine oxide group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms, or can combine with adjacent groups to form a ring with each other. For example, R1 and R2 can be a substituted or unsubstituted carbazolyl group or a substituted or unsubstituted phenyl group. For example, in the case where R1 and R2 combine with their respective adjacent groups to form a ring with each other, R1 can form a ring with L adjacent to R1. Specifically, in the case where R1 is N and L is C, a ring such as can be formed. However, the examples are not limited thereto.

[0127] a to c can each independently be an integer of 0 or more and 2 or less. For example, in the case where a to c are integers of 2 or more, each of the plurality of R1, the plurality of R2, and the plurality of L can all be the same or at least one can be different.

[0128] The second host represented by Chemical Formula H-1 can be represented by the following Chemical Formula H-1a.

[0129] [Chemical Formula H-1a]

[0130]

[0131] In the Chemical Formula H-1a, the descriptions of Ar3, R1, R2, L, and a to c can apply the same descriptions as those defined in Chemical Formula H-1.

[0132] The second dopant of the second light-emitting layer EML2 of the organic electroluminescent element 10 of one embodiment can be a phosphorescent dopant. The second dopant can include an organometallic compound. For example, the second dopant can include iridium (Ir), platinum (Pt), palladium (Pd), or gold (Au).

[0133] However, the embodiment is not limited thereto, and the second dopant can be used without limitation as a phosphorescent dopant substance using common materials known in the art. For example, the phosphorescent dopant can use a metal complex including iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), gold (Au), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb) or thulium (Tm). Specifically, iridium(III)bis(4,6-difluorophenylpyridinyl-N,C2′)picolinate (FIrpic:iridium(III)bis(4,6-difluorophenylpyridinato-N,C2′)picolinate), bis(2,4-difluorophenylpyridinyl)-tetrakis(1-pyrazolyl)borate iridium(III)) (FIr6:Bis(2,4-difluorophenylpyridinato)-tetrakis(1-pyrazolyl)borate iridium(III)) or platinum octaethylporphyrin (PtOEP:platinum octaethylporphyrin) can be used as the phosphorescent dopant. However, the embodiment is not limited thereto.

[0134] The organic electroluminescent element 10 of one embodiment may include a first host and a first dopant represented by the above chemical formula D-1 in the first emission layer EML1. The first dopant may include an anthracene derivative. The lowest triplet excitation energy level (T1 level) of the first dopant may be less than 2.0 eV.

[0135] The second light emitting layer EML2 may include a second host represented by the above chemical formula H-1 and a second dopant. The second dopant may be a phosphorescent dopant. The second light emitting layer EML2 according to an embodiment may emit green phosphorescence, but the embodiment is not limited thereto.

[0136] In the organic electroluminescent element 10 of one embodiment, the first light-emitting layer EML1 and the second light-emitting layer EML2 may be arranged adjacent to each other. Specifically, the first light-emitting layer EML1 and the second light-emitting layer EML2 may be in contact with each other. By making the first light-emitting layer EML1 and the second light-emitting layer EML2 in contact with each other, the excitons generated in the light-emitting layers EML1 and EML2 may move to each other.

[0137] For example, when the lowest triplet excitation energy level (T1 level) of the first dopant is 2.0 eV or less, part of the energy of excitons generated from the light-emitting layers EML1 and EML2 may be transferred to the T1 level of the first dopant.

[0138] In one embodiment, the thickness of the first emission layer EML1 may be greater than or equal to about 1 nm and less than or equal to 10 nm. For example, the thickness of the first emission layer EML1 may be 3 nm. The thickness of the second emission layer EML2 may be greater than or equal to 10 nm and less than or equal to 100 nm. For example, the thickness of the second emission layer EML2 may be 40 nm. By adjusting the thickness of the first emission layer EML1 to be thinner than the thickness of the second emission layer EML2, the degree of light emission of the first emission layer EML1 may be lower than the degree of light emission of the second emission layer EML2. That is, the excitons of the first dopant that move to the first emission layer EML1 may not emit light in the first emission layer EML1 but may be trapped, and the layer that substantially emits light in the organic electroluminescent element 10 may be the second emission layer EML2. In the organic electroluminescent element 10 of one embodiment, the first emission layer EML1 of the thin film and the second emission layer EML2 that substantially emits light may be arranged adjacent to each other to adjust the concentration of the generated excitons, whereby deterioration of the entire organic electroluminescent element 10 can be prevented and the lifespan can be increased.

[0139] In one embodiment, the first dopant represented by Chemical Formula D-1 may be represented by one of the compounds shown in Compound Group 1 below. The first emission layer EML1 may include at least one of the compounds shown in Compound Group 1 below as the first dopant.

[0140] [Compound Group 1]

[0141]

[0142]

[0143]

[0144]

[0145] In one embodiment, the second host represented by Chemical Formula H-1 may include at least one of the compounds shown in Compound Group 2 below.

[0146] [Compound Group 2]

[0147]

[0148]

[0149]

[0150]

[0151] The organic electroluminescent element 10 of one embodiment can combine the first dopant for the first light-emitting layer EML1 and the second host for the second light-emitting layer EML2 to exhibit excellent luminous efficiency and lifetime characteristics.

[0152] In addition, in Figures 1a to 4 the organic electroluminescent element 10 of one embodiment shown, an electron transport region ETR is provided on the first light-emitting layer EML1 and the second light-emitting layer EML2. Although the electron transport region ETR may include at least one of a hole blocking layer HBL, an electron transport layer ETL, and an electron injection layer EIL, the embodiment is not limited thereto.

[0153] The electron transport region ETR may have a single-layer structure composed of a single substance, a single-layer structure composed of a plurality of different substances, or a multi-layer structure having a plurality of layers composed of a plurality of different substances.

[0154] For example, the electron transport region ETR may have a single-layer structure of an electron injection layer EIL or an electron transport layer ETL, or may have a single-layer structure composed of an electron injection substance and an electron transport substance. Also, the electron transport region ETR may have a single-layer structure composed of a plurality of different substances or an electron transport layer ETL / electron injection layer EIL, hole blocking layer HBL / electron transport layer ETL / electron injection layer EIL structure laminated in sequence from the light-emitting layers EML1, EML2, but is not limited thereto. The thickness of the electron transport region ETR may be, for example, about to about

[0155] The electron transport region ETR can be formed by various methods such as vacuum deposition, spin coating, casting, LB method (Langmuir-Blodgett), inkjet printing, laser printing, laser thermal transfer method (LITI: Laser Induced Thermal Imaging).

[0156] In the case where the electron transport region ETR includes an electron transport layer ETL, the electron transport region ETR may include an anthracene-based compound. However, it is not limited thereto. The electron transport region ETR may include, for example, tris(8-hydroxyquinolino)aluminum (Alq3), 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, 2-(4-(N-phenylbenzoimidazole-1-yl)phenyl)-9,10-dinaphthylanthracene, 1,3,5-tri(1-phenyl-1H-benzo[d]imidazole-2-yl)phenyl (TPBi), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), 4-(naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole (NTAZ), 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (tBu-PBD), bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-biphenyl-4-yl)aluminum (BAlq),(1'-Biphenyl-4-olate)aluminum), bis(benzoquinolin-10-yl)beryllium (Bebq2: beryllium bis(benzoquinolin-10-olate)), 9,10-di(naphthalene-2-yl)anthracene (ADN), 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene (BmPyPhB), and mixtures thereof. The thickness of the electron transport layer ETL can be about, to about For example, it can be about to about When the thickness of the electron transport layer ETL satisfies the range described above, relatively satisfactory electron transport characteristics can be obtained without substantially increasing the driving voltage.

[0157] When the electron transport region ETR includes an electron injection layer EIL, the electron transport region ETR can use, for example, metal halides such as LiF, NaCl, CsF, RbCl, RbI, lanthanide metals such as Yb, metal oxides such as Li2O, BaO, or lithium quinolate (LiQ), etc., but is not limited thereto. The electron injection layer EIL can also be composed of a substance mixed with an electron transport material and an insulating organo metal salt. The organo metal salt can be a substance with an energy band gap of about 4 eV or more. Specifically, for example, the organo metal salt can include metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate, or metal stearate. The thickness of the electron injection layer EIL can be about to about about to about When the thickness of the electron injection layer EIL satisfies the range described above, relatively satisfactory electron injection characteristics can be obtained without substantially increasing the driving voltage.

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

[0159] The second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 may be a common electrode or a cathode. The second electrode EL2 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. In the case where the second electrode EL2 is a transmissive electrode, the second electrode EL2 may include a transparent metal oxide, for example, indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc.

[0160] In the case where the second electrode EL2 is a semi-transmissive electrode or a reflective electrode, the second electrode EL2 may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture containing them (for example, a mixture of Ag and Mg). Alternatively, it may be a multilayer structure including a reflective film or a semi-transmissive film formed of the above substances and a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc.

[0161] Although not shown, the second electrode EL2 may be connected to an auxiliary electrode. If the second electrode EL2 is connected to the auxiliary electrode, the resistance of the second electrode EL2 can be reduced.

[0162] In addition, a encapsulation layer CPL may be disposed on the second electrode EL2 of the organic electroluminescent element 10 according to an embodiment. The encapsulation layer CPL may include, for example, α-NPD, NPB, TPD, m-MTDATA, Alq3, CuPc, N4,N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine (TPD15: N4,N4,N4',N4'-tetra(biphenyl-4-yl)biphenyl-4,4'-diamine), 4,4',4"-Tris(carbazol-9-yl)triphenylamine (TCTA: 4,4',4"-Tris(carbazol-9-yl)triphenylamine), N,N'-bis(naphthalen-1-yl) (N,N'-bis(naphthalen-1-yl)), etc.

[0163] As described above, the organic electroluminescent element 10 according to an embodiment of the present invention can exhibit excellent luminous efficiency and long-life characteristics by optimizing the combination of the first dopant of the first light-emitting layer EML1 and the second host of the second light-emitting layer EML2. In addition, the organic electroluminescent element 10 according to an embodiment can exhibit high luminous efficiency and long-life characteristics in the green wavelength region.

[0164] Hereinafter, a compound according to an embodiment of the present invention and an organic electroluminescent element according to an embodiment will be described in detail with reference to Examples and Comparative Examples. In addition, the Examples shown below are examples for helping the understanding of the present invention, and the scope of the present invention is not limited thereto.

[0165] [Examples]

[0166] (Manufacture of Organic Electroluminescent Element)

[0167] The organic electroluminescent elements of the Examples and Comparative Examples were manufactured by cutting an ITO glass substrate into a size of about 50 mm x 50 mm x 0.5 mm, ultrasonically cleaning with isopropyl alcohol and distilled water for 15 minutes respectively, irradiating ultraviolet rays for about 30 minutes, and then exposing to ozone, and then setting it in a vacuum deposition apparatus. Thereafter, a hole injection layer with a thickness of about 70 nm was formed with HTM-01, and a hole transport layer with a thickness of about 10 nm was formed with TCTA. Thereafter, a second light-emitting layer with a thickness of about 40 nm was formed by co-depositing a second host and a second dopant according to an embodiment, and a first light-emitting layer with a thickness of about 5 nm was formed by co-depositing a first host and a first dopant.

[0168] An electron transport layer with a thickness of about 30 nm was formed with the following compound ETM-01. An electron injection layer with a thickness of 1 nm was formed with LiF, and then a second electrode with a thickness of 200 nm was formed with Al. Each layer was formed by a vacuum deposition method.

[0169] The materials for each layer used in manufacturing an organic electroluminescent element are as follows.

[0170] [Functional layer compound]

[0171]

[0172] [Example compound]

[0173]

[0174]

[0175] [First dopant comparative example compound]

[0176]

[0177] The combinations of light-emitting layer materials used in the examples and comparative examples are shown in Table 1 below.

[0178]

Table 1

[0179]

[0180]

[0181] (Characteristic evaluation of organic electroluminescent element)

[0182] The characteristics of the manufactured organic electroluminescent element were evaluated using a luminance orientation characteristic measuring device. The driving voltage, luminous efficiency, and lifetime were measured to evaluate the characteristics of the organic electroluminescent elements according to the examples and comparative examples. The luminous efficiency (%) of the manufactured organic electroluminescent element at a current density of 10 mA / cm 2 , luminance of 13500 cd / m 2 is shown in Table 2. Also, the element lifetime, which is the time required for the luminance to decrease from a luminance reference of 13500 cd / m 2 to the 95% level, was shown. The element lifetime was measured by continuously driving at a current density of 10 mA / cm 2 . Also, the luminance spectra of the examples and comparative examples were measured using a spectro-radiance meter. The emission peak as the maximum emission wavelength was measured from the measured luminance spectra.

[0183]

Table 2

[0184]

[0185]

[0186] Referring to the results in Table 2, for the combination of the first host, the second host, the first dopant, and the second dopant according to an embodiment, it can be confirmed that the luminous efficiency and the device lifetime are improved, and it has a low driving voltage. Referring to the results of Examples 1 to 12 and Comparative Examples 1 to 3, it can be seen that excellent luminous efficiency and long lifetime characteristics are shown in the case of the examples.

[0187] Referring to the results of Example 1 and Comparative Examples 1 and 2, it can be confirmed that two or more of the luminous efficiency, the device lifetime, and the driving voltage of Example 1 show excellent device characteristics compared to Comparative Examples 1 and 2. That is, it can be confirmed that the case including all of the plurality of light-emitting layers shows excellent device characteristics compared to the case including only one light-emitting layer. In the organic electroluminescent device 10 according to an embodiment including a plurality of light-emitting layers, the deterioration of the device can be prevented by adjusting the concentration of excitons in the first light-emitting layer EML1, and the device lifetime and the luminous efficiency can be improved by effectively performing phosphorescent emission in the second light-emitting layer EML2.

[0188] Referring to the results of Examples 1 to 12 and Comparative Example 3, it can be confirmed that the luminous efficiency, the device lifetime, and the driving voltage of Examples 1 to 12 all show excellent device characteristics compared to Comparative Example 3. That is, it can be confirmed that in the case where the lowest triplet excitation energy level (T1 level) of the first dopant is 2.0 eV or less, the energy of the excitons generated in the light-emitting layers EML1 and EML2 moves to the lowest triplet excitation energy level (T1 level) of the first dopant, so that the concentration of the excitons for light emission can be adjusted, and both the device lifetime and the driving voltage can be improved.

[0189] The organic electroluminescent device 10 according to an embodiment includes a first light-emitting layer EML1 and a second light-emitting layer EML2, and can combine the first host and the first dopant of the first light-emitting layer EML1 and the second host and the second dopant of the second light-emitting layer EML2 to show excellent luminous efficiency and improved lifetime characteristics. Moreover, the organic electroluminescent device 10 according to an embodiment includes a first dopant having a lowest triplet excitation energy level (T1 level) of 2.0 eV or less, so that the exciton concentration of the device can be adjusted, and high luminous efficiency and long lifetime characteristics can be shown.

[0190] As mentioned above, although the present invention has been described with reference to the preferred embodiments of the present invention, those skilled in the art or those with ordinary knowledge in the technical field can understand that various modifications and changes can be made to the present invention without departing from the spirit and technical field of the present invention described in the claims.

[0191] Therefore, the technical scope of the present invention should not be limited to the content described in the detailed description of the specification, but should be determined by the claims.

Claims

1. An organic electroluminescent element, comprising: The first electrode; The second electrode, disposed on the first electrode; And The first light-emitting layer and the second light-emitting layer, disposed between the first electrode and the second electrode, Wherein, the first light-emitting layer includes a first host and a first dopant, The second light-emitting layer includes a second host represented by the following chemical formula H-1a and a second dopant different from the first dopant and containing an organometallic compound, The first light-emitting layer and the second light-emitting layer are adjacent to each other: [Chemical formula H-1a] In the chemical formula H-1a, Ar3 is an aryl group with 6 or more and 60 or less ring carbon atoms which is substituted or unsubstituted, or a heteroaryl group with 2 or more and 60 or less ring carbon atoms which is substituted or unsubstituted, L is a direct bond, a substituted or unsubstituted silyl group, a substituted or unsubstituted boronic group, a substituted or unsubstituted alkylene group with 1 or more and 30 or less carbon atoms, a substituted or unsubstituted arylene group with 6 or more and 60 or less ring carbon atoms, or a substituted or unsubstituted heteroarylene group with 2 or more and 60 or less ring carbon atoms, R1 and R2 are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted phosphine oxide group, a substituted or unsubstituted alkyl group with 1 or more and 30 or less carbon atoms, a substituted or unsubstituted aryl group with 6 or more and 60 or less ring carbon atoms, or a substituted or unsubstituted heteroaryl group with 2 or more and 60 or less ring carbon atoms, or combine with adjacent groups to form a ring, a to c are each independently an integer of 0 or more and 2 or less, Wherein, the first dopant is represented by the following chemical formula D-1: [Chemical formula D-1] In the chemical formula D-1, R 11 to R 18 are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring carbon atoms, L 11 and L 12 are each independently a direct bond, a substituted or unsubstituted amino group, a substituted or unsubstituted silyl group, a substituted or unsubstituted boryl group, a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms, a substituted or unsubstituted arylene group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 60 ring carbon atoms, Ar 11 and Ar 12 are each independently an optionally substituted alkenyl having 2 to 30 carbon atoms, an optionally substituted silyl group, an optionally substituted seleno group, an optionally substituted amino group, an optionally substituted aryl group having 6 to 60 ring carbon atoms, or an optionally substituted heteroaryl group having 2 to 60 ring carbon atoms. m and n are each independently an integer of 0 or more and 3 or less.

2. The organic electroluminescent element according to claim 1, wherein: The first dopant is represented by the following chemical formula D-1a, chemical formula D-1b or chemical formula D-1c: [Chemical formula D-1a] [Chemical formula D-1b] [Chemical formula D-1c] In the chemical formula D-1a, chemical formula D-1b, and chemical formula D-1c, Ar 11 , Ar 12 , R 11 to R 18 are the same as those defined in chemical formula D-1.

3. The organic electroluminescent element according to claim 1, wherein, The second dopant includes iridium, platinum, palladium or gold.

4. The organic electroluminescent element according to claim 1, wherein, The lowest triplet excitation energy level of the first dopant is 2.0 eV or less.

5. The organic electroluminescent element according to claim 1, wherein, The thickness of the first light-emitting layer is 1 nm or more and 10 nm or less.

6. The organic electroluminescent element according to claim 1, wherein, The second light-emitting layer is disposed between the first light-emitting layer and the first electrode.

7. The organic electroluminescent element according to claim 1, wherein, The first light-emitting layer is in contact with the second light-emitting layer.

8. The organic electroluminescent element according to claim 1, wherein, The first dopant includes at least one of the compounds represented in the following compound group 1: [Compound group 1] 9. The organic electroluminescent element according to claim 1, wherein, The second host includes at least one of the compounds represented in the following compound group 2: [Compound group 2] 10. An organic electroluminescent element, comprising: The first electrode; The second electrode, disposed on the first electrode; And The first light-emitting layer and the second light-emitting layer, disposed between the first electrode and the second electrode, Wherein, the first light-emitting layer includes a first host and a first dopant represented by the following chemical formula D-1, The second light-emitting layer includes a second host represented by the following chemical formula H-1a and a second dopant different from the first dopant: [Chemical formula D-1] [Chemical formula H-1a] In the chemical formula D-1, R 11 to R 18 are each independently a hydrogen atom, a deuterium atom, a substituted or unsubstituted amino group, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 60 ring-forming carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 60 ring-forming carbon atoms, L 11 and L 12 are each independently a direct bond, a substituted or unsubstituted amino group, a substituted or unsubstituted silyl group, a substituted or unsubstituted boron group, a substituted or unsubstituted alkylene group having 1 to 30 carbon atoms, a substituted or unsubstituted arylene group having 6 to 60 ring carbon atoms, or a substituted or unsubstituted heteroarylene group having 2 to 60 ring carbon atoms, Ar 11 and Ar 12 each independently is an optionally substituted alkenyl having 2 to 30 carbon atoms, an optionally substituted silyl group, an optionally substituted seleno group, an optionally substituted amino group, an optionally substituted aryl group having 6 to 60 ring carbon atoms, or an optionally substituted heteroaryl group having 2 to 60 ring carbon atoms, m and n are each independently an integer of 0 or more and 3 or less, in the chemical formula H-1a, Ar3 is an aryl group having 6 to 60 ring-constituting carbon atoms which may be substituted or unsubstituted, or a heteroaryl group having 2 to 60 ring-constituting carbon atoms which may be substituted or unsubstituted, L is a direct bond, a silyl group which may be substituted or unsubstituted, a boron group which may be substituted or unsubstituted, an alkylene group having 1 to 30 carbon atoms which may be substituted or unsubstituted, an arylene group having 6 to 60 ring-constituting carbon atoms which may be substituted or unsubstituted, or a heteroarylene group having 2 to 60 ring-constituting carbon atoms which may be substituted or unsubstituted, R1 and R2 are each independently a hydrogen atom, a deuterium atom, a silyl group which may be substituted or unsubstituted, a phosphine oxide group which may be substituted or unsubstituted, an alkyl group having 1 to 30 carbon atoms which may be substituted or unsubstituted, an aryl group having 6 to 60 ring-constituting carbon atoms which may be substituted or unsubstituted, or a heteroaryl group having 2 to 60 ring-constituting carbon atoms which may be substituted or unsubstituted, or combine with adjacent groups to form a ring with each other, a to c are each independently an integer of 0 or more and 2 or less.

11. The organic electroluminescent element according to claim 10, wherein, The first dopant is represented by the following chemical formula D-1a, chemical formula D-1b or chemical formula D-1c: [Chemical formula D-1a] [Chemical formula D-1b] [Chemical formula D-1c] In the chemical formulae D-1a, D-1b, and D-1c, Ar 11 , Ar 12 , R 11 to R 18 are the same as those defined in the chemical formula D-1.

12. The organic electroluminescent element according to claim 10, wherein, The second dopant includes iridium, platinum, palladium or gold.

13. The organic electroluminescent element according to claim 10, wherein, The lowest triplet excitation energy level of the first dopant is 2.0 eV or less.

14. The organic electroluminescent element according to claim 10, wherein, The thickness of the first light-emitting layer is 1 nm or more and 10 nm or less.

15. The organic electroluminescent element according to claim 10, wherein, The second light-emitting layer is disposed between the first light-emitting layer and the first electrode.

16. The organic electroluminescent element according to claim 10, wherein, The first dopant includes at least one compound selected from the compounds represented in the following compound group 1: [Compound group 1] 17. The organic electroluminescent element according to claim 10, wherein, The second host includes at least one compound selected from the compounds represented in the following compound group 2: [Compound group 2]

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