Crosslinking compound and method for producing organic electroluminescent device

Abstract

To provide an organic electroluminescent element with improved emission efficiency and driving voltage properties.MEANS FOR SOLVING THE PROBLEM: An organic electroluminescent element of an embodiment of the present disclosure includes a first electrode, a hole transport region, an emission layer, an electron transport region, and a second electrode, stacked one by one, wherein the hole transport region includes a hole transport material derived from a crosslinking agent compound represented by Formula 1 below. The organic electroluminescent element may be manufactured through a wet process, and the emission efficiency and driving voltage properties of the organic electroluminescent element may be improved.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an organic electroluminescent device and a crosslinking compound used therein, and more particularly to a crosslinking compound used as a material for forming a hole transport region and an organic electroluminescent device including the same. [Background technology]

[0002] Recently, organic electroluminescence displays (OLEDs) have been actively developed as image display devices. Unlike liquid crystal displays and the like, OLEDs are so-called self-emissive display devices that realize display by causing luminescent materials containing organic compounds in the luminescent layer to emit light by recombining holes and electrons injected from the first and second electrodes in the luminescent layer.

[0003] In order to apply organic electroluminescent devices to display devices, there is a demand for lower driving voltages, higher luminous efficiency, and longer lifespans of the organic electroluminescent devices, and there is a continuous demand for the development of materials for organic electroluminescent devices that can stably achieve these demands.

[0004] Furthermore, developments are being made on materials for the hole transport layer in order to realize highly efficient organic electroluminescent devices. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide an organic electroluminescent device having improved luminous efficiency and driving voltage characteristics.

[0006] Another object of the present invention is to provide an organic electroluminescent device that can be manufactured through a wet process, and a crosslinker compound applicable thereto. [Means for solving the problem]

[0007] An organic electroluminescent device according to one embodiment of the present invention includes a first electrode, a hole transport region disposed on the first electrode, an emitting layer disposed on the hole transport region, an electron transport region disposed on the emitting layer, and a second electrode disposed on the electron transport region, wherein the hole transport region includes a hole transport material derived from a crosslinker compound represented by the following Chemical Formula 1: [ka] ...(chemical formula 1) In the above Chemical Formula 1, A is a hydrogen atom or a deuterium atom, L1 and L2 each independently represent a single bond or a substituted or unsubstituted methylene group, m is an integer of 1 or more and 100 or less, and n1 and n2 each independently represent 1 or 2.

[0008] The hole transport region may include a hole injection layer disposed on the first electrode and a hole transport layer disposed on the hole injection layer, and the hole transport layer may include the hole transport material derived from the crosslinker compound represented by Chemical Formula 1.

[0009] The hole transport region may include a plurality of organic layers, and an organic layer adjacent to the light emitting layer among the plurality of organic layers may include the hole transport material derived from a crosslinker compound represented by Chemical Formula 1.

[0010] The crosslinker compound represented by Chemical Formula 1 may be represented by the following Chemical Formula 1-1 or Chemical Formula 1-2. [ka] ...(chemical formula 1-1) [ka] ...(chemical formula 1-2) In the formulas 1-1 and 1-2, A is as defined in the formula 1.

[0011] The hole transport material may further include a polymer compound containing a substituted or unsubstituted triarylamino group.

[0012] The polymer compound may be represented by the following chemical formula 2-1 or 2-2. [ka] ...(chemical formula 2-1) [ka] ...(Chemical formula 2-2) In Chemical Formula 2-1 and Chemical Formula 2-2, R1 to R7 each independently represent a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms; a1 represents an integer of from 0 to 5; a2 and a3 each independently represent an integer of from 0 to 4; a4 and a5 each independently represent an integer of from 0 to 3; and p1 and p2 each independently represent an integer of from 1 to 100.

[0013] The polymer compound may be represented by the following chemical formula 2-1-1, chemical formula 2-1-2, or chemical formula 2-2-1. [ka] ...(Chemical formula 2-1-1) [ka] ...(Chemical formula 2-1-2) [ka] ...(Chemical formula 2-2-1) In the chemical formulas 2-1-1, 2-1-2, and 2-2-1, p1 and p2 are as defined in the chemical formulas 2-1 and 2-2.

[0014] The weight ratio of the polymer compound and the crosslinker compound contained in the hole transport material may be 4:1 to 19:1.

[0015] In the hole transport region, the polymer compound may be thermally or photo-crosslinked with the crosslinker compound.

[0016] The crosslinker compound according to one embodiment of the present invention is represented by the following Chemical Formula 1: [ka] ...(chemical formula 1) In the above Chemical Formula 1, A is a hydrogen atom or a deuterium atom, L1 and L2 each independently represent a single bond or a substituted or unsubstituted methylene group, m is an integer of 1 or more and 100 or less, and n1 and n2 each independently represent 1 or 2.

[0017] A method for manufacturing an organic electroluminescent device according to an embodiment of the present invention includes providing a first electrode; providing a hole transport material on the first electrode to form a hole transport region; forming an emitting layer on the hole transport region; and forming a second electrode on the emitting layer, wherein the hole transport material comprises a compound represented by Chemical Formula 1.

[0018] In the method for manufacturing an organic electroluminescent device according to an embodiment of the present invention, the hole transport layer may be formed via the hole transport material.

[0019] The method may further include preparing the hole transport material by mixing the polymer compound, the crosslinker compound, and a solvent before providing the hole transport material on the first electrode.

[0020] Forming the hole transport region may further include, after providing the hole transport material, applying heat or light to cure the provided hole transport material.

[0021] The application of the hole transport material may be performed via a wet process such as spin coating, inkjet printing, nozzle printing, or spray printing. [Effects of the Invention]

[0022] The organic electroluminescent device of one embodiment exhibits improved device characteristics such as low driving voltage and high efficiency.

[0023] The crosslinker compound of one embodiment is used in the process of forming a hole transport region of an organic electroluminescent device, and contributes to improving the resolution and efficiency of the organic electroluminescent device. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present invention. [Figure 3] 1 is a cross-sectional view schematically illustrating an organic electroluminescent device according to an embodiment of the present invention. [Figure 4A] 1A to 1C are cross-sectional views schematically illustrating some steps of a method for manufacturing an organic electroluminescent device according to an embodiment of the present invention. [Figure 4B] 1A to 1C are cross-sectional views schematically illustrating some steps of a method for manufacturing an organic electroluminescent device according to an embodiment of the present invention. [Figure 4C] 1A to 1C are cross-sectional views schematically illustrating some steps of a method for manufacturing an organic electroluminescent device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] Because the present invention can be modified in various ways and can have various forms, specific embodiments are shown by way of example in the drawings and described in detail herein, but it is not intended to limit the invention to the particular disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and alternatives falling within the spirit and technical scope of the invention.

[0026] As used herein, when a component (or region, layer, portion, etc.) is referred to as being "on," "coupled," or "bonded" to another component, it means that it may be directly positioned, coupled, or bonded to the other component, or that a third component may be disposed therebetween.

[0027] The same reference numerals refer to the same components, and in the drawings, thicknesses, proportions, and dimensions of the components are exaggerated for the purpose of effectively explaining the technical contents.

[0028] "And / or" includes all combinations of one or more of the associated constructs.

[0029] Terms such as "first" and "second" are used to describe various components, but the components are not limited to these terms. These terms are used only to distinguish one structural element from another. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component, without departing from the scope of the present invention. A singular expression includes a plural expression unless the context clearly dictates otherwise.

[0030] Furthermore, terms such as "under," "below," "on," and "above" are used to describe the relative relationships of components shown in the drawings. These terms are relative concepts and are described based on the directions shown in the drawings.

[0031] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted to have a meaning consistent with the meaning in the context of the relevant art, and are expressly defined herein unless interpreted in an idealized or overly formal sense.

[0032] It should be understood that the terms "comprise" or "have" imply the presence of any feature, number, step, operation, component, part, or combination thereof stated in the specification above, but do not preclude the presence or possible addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0033] In this specification, the term "substituted or unsubstituted" means being substituted with 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 sulfinyl group, a sulfonyl group, a carbonyl group, a boryl group, a phosphine oxide group, a phosphine sulfide group, an alkyl group, an alkenyl group, an alkoxy group, a hydrocarbon ring group, an aryl group, and a heterocyclic group. Each of the substituents exemplified above may be substituted or unsubstituted. For example, a biphenylyl group may be interpreted as an aryl group, or as a phenyl group substituted with a phenyl group.

[0034] In this specification, "adjacent groups bond to each other to form a ring" means that adjacent groups bond to each other 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. The ring formed by bonding adjacent groups to each other is a monocycle or a polycycle. Furthermore, the ring formed by bonding to each other may be bonded to another ring to form a spiro structure.

[0035] In this specification, the term "adjacent groups" refers to a substituent substituted on an atom directly bonded to the atom on which the substituent is substituted, another substituent substituted on the atom on which the substituent is substituted, or a substituent sterically most adjacent to the substituent. For example, two methyl groups in 1,2-dimethylbenzene are interpreted as "adjacent groups" to each other, and two ethyl groups in 1,1-diethylcyclopentane are interpreted as "adjacent groups" to each other.

[0036] As used herein, a direct bond is a single bond.

[0037] In this specification, examples of halogen atoms include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0038] In this specification, an alkyl group is straight-chain, branched-chain, or cyclic. The number of carbon atoms in the alkyl group is 1 to 50, 1 to 30, 1 to 20, 1 to 10, or 1 to 6. Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, s-butyl, t-butyl, i-butyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, i-pentyl, neopentyl, t-pentyl, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl ...,3-dimethylbutyl, n-pentyl, i-pentyl, 2-ethylpentyl, 3,3-dimethylbutyl, n Hexyl group, 2-butylhexyl group, cyclohexyl group, 4-methylcyclohexyl group, 4-t-butylcyclohexyl group, n-heptyl group, 1-methylheptyl group, 2,2-dimethylheptyl group, 2-ethylheptyl group, 2-butylheptyl group, n-octyl group, t-octyl group, 2-ethyloctyl group, 2-butyloctyl group, 2-hexyloctyl group, 3,7-dimethyloctyl group, cyclooctyl group, n-nonyl group, n-decyl group, adamantyl group n-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butylhexadecyl, 2-hexylhexadecyl, 2-octylhexadecyl , n-heptadecyl group, n-octadecyl group, n-nonadecyl group, n-icosyl group, 2-ethylicosyl group, 2-butylicosyl group, 2-hexylicosyl group, 2-octylicosyl group, n-henicosyl group, n-docosyl group, n-tricosyl group, n-tetracosyl group, n-pentacosyl group, n-hexacosyl group, n-heptacosyl group, n-octacosyl group, n-nonacosyl group, and n-triacontyl group, but are not limited to these.

[0039] In this specification, the hydrocarbon ring includes an aliphatic hydrocarbon ring and an aromatic hydrocarbon ring. The heterocycle includes an aliphatic heterocycle and an aromatic heterocycle. The hydrocarbon ring and the heterocycle may be monocyclic or polycyclic.

[0040] In this specification, the hydrocarbon ring group refers to any functional group or substituent derived from an aliphatic hydrocarbon ring or any functional group or substituent derived from an aromatic hydrocarbon ring, and the number of ring carbon atoms in the hydrocarbon ring group is 5 to 60.

[0041] In this specification, a heterocyclic group refers to any functional group or substituent derived from a heterocycle containing at least one heteroatom as a ring-forming atom. The number of ring-forming carbon atoms in a heterocyclic group is 2 to 60. The heterocyclic group contains one or more heteroatoms selected from B, O, N, P, Si, and S. When a heterocyclic group contains two or more heteroatoms, the two or more heteroatoms may be the same or different. A heterocyclic group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group, and is a concept that includes heteroaryl groups. The number of ring-forming carbon atoms in a heterocyclic group may be 2 to 30, 2 to 20, or 2 to 10.

[0042] As used herein, the term "aryl group" refers to 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 carbon atoms of the aryl group may be 6 to 30, 6 to 20, or 6 to 15. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, fluorenyl, anthracenyl, phenanthryl, biphenylyl, terphenylyl, quaterphenylyl, quinquephenylyl, sexiphenylyl, triphenylenyl, pyrenyl, benzofluoranthenyl, and chrysenyl.

[0043] In this specification, the fluorenyl group may be substituted, and two substituents may be bonded to each other to form a spiro structure. Examples of fluorenyl groups that may be substituted include, but are not limited to, the following: [ka]

[0044] In this specification, a heteroaryl group contains one or more heteroatoms selected from the group consisting of B, O, N, P, Si, and S. When a heteroaryl group contains two or more heteroatoms, the two or more heteroatoms may be the same or different. The heteroaryl group may be a monocyclic heterocyclic group or a polycyclic heterocyclic group. The number of ring carbon atoms in the heteroaryl group may be 2 to 30, 2 to 20, or 2 to 10. Examples of heteroaryl groups include a thiophenyl group, a furanyl group, a pyrrolyl group, an imidazolyl group, a thiazolyl group, an oxazolyl group, an oxadiazolyl group, a triazolyl group, a pyridinyl group, a bipyridinyl group, a pyrimidinyl group, a triazinyl group, a triazolyl group, an acridinyl group, a pyridazinyl group, a pyrazinyl group, a quinolinyl group, a quinazolinyl group, a quinoxalinyl group, a phenoxanyl group, a phthalazinyl group, a pyridopyrimidinyl group, a pyridopyrazinyl group, a pyrazinopyrazinyl group, an isoquinolinyl group, an indophenyl ... Examples of the alkyl group include, but are not limited to, an alkyl 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 benzothiophenyl group, a dibenzothiophenyl group, a thienothiophenyl group, a benzofuranyl group, a phenanthrolinyl group, an isoxazolyl group, a thiadiazolyl group, a phenothiazinyl group, a dibenzosilolyl group, and a dibenzofuranyl group.

[0045] In this specification, the same explanation as for the aryl group as above applies to an arylene group, except that the arylene group is a divalent group. The same explanation as for the heteroaryl group as above applies to a heteroarylene group, except that the heteroarylene group is a divalent group.

[0046] In this specification, the alkenyl group may be linear or branched. The number of carbon atoms is not particularly limited, but may be 2 to 30, 2 to 20, or 2 to 10. Examples of the alkenyl group include, but are not limited to, a vinyl group, a 1-butenyl group, a 1-pentenyl group, a 1,3-butadienylaryl group, a styrenyl group, and a styrylvinyl group.

[0047] As used herein, the term "silyl group" includes alkylsilyl groups and arylsilyl groups. Examples of silyl groups include, but are not limited to, trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, and phenylsilyl groups.

[0048] As used herein, the term "boryl group" includes alkylboryl groups and arylboryl groups. Examples of boryl groups include, but are not limited to, trimethylboryl groups, triethylboryl groups, t-butyldimethylboryl groups, triphenylboryl groups, diphenylboryl groups, and phenylboryl groups.

[0049] In this specification, the number of carbon atoms in the amino group is not particularly limited, but may be from 1 to 30. The amino group includes an alkylamino group and an arylamino group. Examples of the amino group include, but are not limited to, a methylamino group, a dimethylamino group, a phenylamino group, a diphenylamino group, a naphthylamino group, a 9-methyl-anthracenylamino group, and a triphenylamino group.

[0050] JPEG0007740893000011.jpg12161

[0051] Hereinafter, an organic electroluminescent device according to an embodiment of the present invention will be described with reference to the drawings.

[0052] 1 to 3 are cross-sectional views schematically illustrating an organic electroluminescent device according to one embodiment of the present invention. Referring to FIGS. 1 to 3, in an organic electroluminescent device 10 according to one embodiment, a first electrode EL1 and a second electrode EL2 are disposed opposite each other, and a plurality of organic layers are disposed between the first electrode EL1 and the second electrode EL2. The plurality of organic layers includes a hole transport region HTR, an emission layer EML, and an electron transport region ETR. That is, the organic electroluminescent device 10 according to one embodiment of the present invention includes a first electrode EL1, a hole transport region HTR, an emission layer EML, an electron transport region ETR, and a second electrode EL2, which are stacked in sequence. Although not shown, a capping layer may be further disposed on the second electrode EL2.

[0053] In one embodiment, the organic electroluminescent device 10 includes a crosslinker compound according to an embodiment described below in at least one of a plurality of organic layers disposed between the first electrode EL1 and the second electrode EL2. For example, in one embodiment, the organic electroluminescent device 10 includes a crosslinker compound according to an embodiment described below in the hole transport region HTR disposed between the first electrode EL1 and the second electrode EL2. However, the embodiment is not limited thereto. In one embodiment, the organic electroluminescent device 10 may include a crosslinker compound according to an embodiment described below in at least one organic layer included in the emission layer EML and the electron transport region ETR, which are the plurality of organic layers disposed between the first electrode EL1 and the second electrode EL2, in addition to the hole transport region HTR. Alternatively, the organic electroluminescent device 10 may include a crosslinker compound according to an embodiment described below in a functional layer, such as a capping layer, disposed on the second electrode EL2.

[0054] 2 is a cross-sectional view of an organic electroluminescent device 10 according to 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, unlike Fig. 1. Also, Fig. 3 is a cross-sectional view of an organic electroluminescent device 10 according to an embodiment, in which the hole transport region HTR includes a hole injection layer HIL, a hole transport layer HTL, and an electron blocking layer EBL, and the electron transport region ETR includes an electron injection layer EIL, an electron transport layer ETL, and a hole blocking layer HBL, unlike Fig. 1.

[0055] The first electrode EL1 is conductive. The first electrode EL1 is made of a metal alloy or a conductive compound. The first electrode EL1 is an anode. The first electrode EL1 is also a pixel electrode. The first electrode EL1 is a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the first electrode EL1 is a transmissive electrode, the first electrode EL1 includes a transparent metal oxide such as ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), or ITZO (indium tin zinc oxide). When the first electrode EL1 is a semi-transmissive electrode or a reflective electrode, the first electrode EL1 includes 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 (e.g., an alloy of Ag and Mg). Alternatively, the first electrode EL1 may have a multi-layer structure including a reflective film or semi-transparent film made of the above-mentioned materials and a transparent conductive film made of ITO, IZO, ZnO, ITZO, etc. For example, the first electrode EL1 may have a triple-layer structure of ITO / Ag / ITO, but is not limited to this. The thickness of the first electrode EL1 may be about 100 nm to about 1000 nm, for example, about 100 nm to about 300 nm.

[0056] The hole transport region HTR is provided on the first electrode EL1. The hole transport region HTR includes 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 may be, for example, about 5 nm to about 150 nm.

[0057] The hole transport region HTR may have a single layer made of a single material, a single layer made of a plurality of different materials, or a multilayer structure having a plurality of layers made of a plurality of different materials.

[0058] 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 a single layer structure of a hole injection material and a hole transport material. The hole transport region HTR may have a single layer structure of multiple different materials, or a structure stacked in order from the first electrode EL1, such as hole injection layer HIL / hole transport layer HTL, hole injection layer HIL / hole transport layer HTL / hole buffer layer (not shown), hole injection layer HIL / hole buffer layer (not shown), hole transport layer HTL / hole buffer layer, or hole injection layer HIL / hole transport layer HTL / electron blocking layer EBL, but is not limited thereto.

[0059] The hole transport region HTR can be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0060] In one embodiment of the organic electroluminescent device 10, the hole transport region HTR includes one embodiment of the crosslinker compound. In one embodiment of the organic electroluminescent device 10, the hole transport region HTR includes one embodiment of the hole transport material HTM (see FIG. 4a) derived from one embodiment of the crosslinker compound.

[0061] In one embodiment, the crosslinker compound comprises a polyacetylene (PA) main chain containing a bisazide group, i.e., two azide groups, and the crosslinker compound comprises a structure in which two azide groups are bonded to both sides of the polyacetylene main chain.

[0062] In one embodiment, the crosslinker compound is represented by the following chemical formula 1: [ka] ...(chemical formula 1)

[0063] In Chemical Formula 1, A is a hydrogen atom or a deuterium atom. In Chemical Formula 1, As may be the same as or different from one another. For example, all As may be hydrogen atoms. Alternatively, at least one of the multiple As may be a deuterium atom, and the rest may be hydrogen atoms. In the crosslinker compound represented by Chemical Formula 1, the polyacetylene constituting the main chain is not substituted with any other substituents other than hydrogen atoms or deuterium atoms.

[0064] In Chemical Formula 1, L1 and L2 are each independently a single bond or a substituted or unsubstituted methylene group. In one embodiment, L1 and L2 are the same or different. For example, L1 and L2 may both be single bonds or both be unsubstituted methylene groups.

[0065] In Chemical Formula 1, m is an integer of 1 or more and 100 or less. When m is an integer of 2 or more, it means that a plurality of acetylene monomers constitute the main chain. In other words, when m is an integer of 2 or more, it means that a plurality of acetylene monomers are repeatedly polymerized. In one embodiment, m is an integer of 3 or more and 20 or less.

[0066] In Chemical Formula 1, n1 and n2 are each independently 1 or 2. When n1 and n2 are each 1, it means that one azide group is bonded to each side of the main chain. When n1 and n2 are each 2, it means that two azide groups are bonded to each side of the main chain. In one embodiment, n1 and n2 are the same or different. For example, n1 and n2 may both be 1 or both be 2.

[0067] In one embodiment, the crosslinker compound has a structure in which one or two pairs of azide groups are bonded to both sides of a polyacetylene chain, which is the main chain. In one embodiment, the crosslinker compound has a structure in which bisazide groups are bonded to both sides of a polyacetylene main chain that is not substituted with any other substituents other than hydrogen or deuterium atoms, thereby increasing the crosslinking efficiency of the polymer compound without reducing the hole transport ability of the polymer compound contained in the hole transport region. Therefore, in the case of an organic electroluminescent device containing the crosslinker compound of one embodiment, forming the hole transport region through a wet process such as inkjet printing can increase the resolution of the organic electroluminescent device and provide an organic electroluminescent device with high luminous efficiency and low driving voltage.

[0068] A crosslinker compound according to one embodiment of the present invention is represented by the following chemical formula 1-a: [ka] ...(chemical formula 1-a)

[0069] In Chemical Formula 1-a, the same as that described in Chemical Formula 1 above applies to A and m.

[0070] In chemical formula 1-a, B is represented by the following chemical formula 1-b or chemical formula 1-c. [ka] ...(chemical formula 1-b) [ka] ...(Chemical formula 1-c)

[0071] TIFF0007740893000016.tif19170

[0072] In Chemical Formula 1-a, the two Bs bonded to both sides of the polyacetylene main chain may be the same or different. In one embodiment, both Bs may be represented by Chemical Formula 1-b. Also, both Bs may be represented by Chemical Formula 1-c.

[0073] A crosslinker compound according to one embodiment of the present invention is represented by the following Chemical Formula 1-1 or 1-2. [ka] ...(chemical formula 1-1) [ka] ...(chemical formula 1-2)

[0074] Chemical Formula 1-1 is a case where, in Chemical Formula 1, m is 3, L1 and L2 are both single bonds, and n1 and n2 are both 1. Chemical Formula 1-2 is a case where, in Chemical Formula 1, m is 3, L1 and L2 are both unsubstituted methylene groups, and n1 and n2 are both 2.

[0075] In Chemical Formula 1-1 and Chemical Formula 1-2, the same as that explained in Chemical Formula 1 above applies to A.

[0076] In an organic electroluminescent device 10 according to an embodiment, the hole transport region HTR further includes a polymer compound having hole transport capability in addition to the crosslinker compound according to an embodiment. The polymer compound includes a substituted or unsubstituted triarylamino group. The polymer compound includes a monomer having a substituted or unsubstituted triarylamino group as a repeating unit.

[0077] The polymer compound according to one embodiment is represented by the following Formula 2-1 or 2-2. More specifically, the polymer compound according to one embodiment is a polymer including repeating units of the monomers represented by the following Formula 2-1 or 2-2. [ka] ...(chemical formula 2-1) [ka] ...(Chemical formula 2-2)

[0078] In Chemical Formula 2-1 and Chemical Formula 2-2, R1 to R7 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms. In one embodiment, R1 to R7 are each independently a hydrogen atom or a substituted or unsubstituted alkyl group having from 1 to 8 carbon atoms. For example, R1 may be a hydrogen atom, a substituted or unsubstituted methyl group, or a substituted or unsubstituted butyl group. For example, R6 to R7 may each independently be a substituted or unsubstituted octyl group.

[0079] In Chemical Formula 2-1 and Chemical Formula 2-2, a1 is an integer of 0 or more and 5 or less. a2 and a3 are each independently an integer of 0 or more and 4 or less. a4 and a5 are each independently an integer of 0 or more and 3 or less. Here, when a1 to a5 are each 0, this means that in the polymer compound according to one embodiment, R1 to R5 are all hydrogen atoms. When a1 to a5 are each an integer of 2 or more, the multiple R1 to R5 may all be the same, or at least one of the multiple R1 to R5 may be different.

[0080] In Chemical Formula 2-1 and Chemical Formula 2-2, p1 and p2 are each independently an integer of 1 to 100. In one embodiment, when p1 and p2 are each an integer of 2 or greater, this means that multiple monomers shown in Chemical Formula 2-1 and Chemical Formula 2-2 are polymerized. In other words, when p1 and p2 are each an integer of 2 or greater, this means that multiple monomers shown in Chemical Formula 2-1 and Chemical Formula 2-2 are repeatedly bonded. In one embodiment, p1 and p2 are each an integer of 3 to 20.

[0081] The polymer compound according to one embodiment is represented by the following Chemical Formula 2-1-1, Chemical Formula 2-1-2, or Chemical Formula 2-2-1. [ka] ...(Chemical formula 2-1-1) [ka] ...(Chemical formula 2-1-2) [ka] ...(Chemical formula 2-2-1)

[0082] Chemical formula 2-1-1, chemical formula 2-1-2, and chemical formula 2-2-1 are the cases where R1 to R7 in chemical formula 2-1 and chemical formula 2-2 are substituted with specific substituents, respectively.

[0083] Meanwhile, in Chemical Formula 2-1-1, Chemical Formula 2-1-2, and Chemical Formula 2-2-1, the same as that described in Chemical Formula 1 above applies to p1 and p2.

[0084] According to one embodiment, the crosslinker compound and the polymer compound are each contained in the hole transport layer HTL of the hole transport region HTR. The weight ratio of the polymer compound and the crosslinker compound contained in the hole transport layer HTL according to one embodiment is about 4:1 to about 19:1. More preferably, the weight ratio of the polymer compound and the crosslinker compound contained in the hole transport layer HTL may be about 9:1. The polymer compound contained in the hole transport layer HTL is thermally crosslinked or photocrosslinked via the crosslinker compound.

[0085] On the other hand, in the organic electroluminescent device 10 according to one embodiment, the hole transport region HTR further includes a known material.

[0086] The hole injection layer HTL may be formed from, for example, a phthalocyanine compound such as copper phthalocyanine, DNTPD (N,N'-diphenyl-N,N'-bis-[4-phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine), m-MTDATA (4,4',4"-[tris(3-methylphenyl)phenylamino)triphenylamine], TDATA (4,4',4"-tris(N,N-diphenylamino)triphenylamine), 2-TNATA (4,4',4"-tris{N,-(2-naphthyl)-N-phenylamino}-triphenylamine), PEDOT / PSS (poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonyl)-1,1-diol), or a phthalocyanine compound such as copper phthalocyanine. sulfonate), PANI / DBSA (polyaniline / dodecylbenzenesulfonic acid), PANI / CSA (polyaniline / camphorsulfonic acid), PANI / PSS ((polyaniline) / poly(4-styrenesulfonate)), NPB (N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine), triphenylamine-containing polyether ketone (TPAPEK), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, HAT-CN (dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile), etc.

[0087] In addition to the crosslinker compound and the polymer compound according to an embodiment, the hole transport layer HTL may include, for example, a carbazole-based derivative such as N-phenylcarbazole or polyvinylcarbazole, a fluorene-based derivative, a triphenylamine-based derivative such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine) or TCTA (4,4',4"-tris(N-carbazolyl)triphenylamine), NPB (N,N'-di(naphthalen-1-yl)-N,N'-diphenyl-benzidine), TAPC (4,4'-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine]), HMTPD (4,4'-bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), or mCP (1,3-bis(N-carbazolyl)benzene).

[0088] The thickness of the hole transport region HTR may be about 5 nm to about 1000 nm, for example, about 10 nm to about 500 nm. The thickness of the hole injection layer HIL may be, for example, about 3 nm to about 100 nm, and the thickness of the hole transport layer HTL may be about 3 nm to about 100 nm. For example, the thickness of the electron blocking layer EBL may be about 1 nm to about 100 nm. When the thicknesses of the hole transport region HTR, hole injection layer HIL, hole transport layer HTL, and electron blocking layer EBL satisfy the above-mentioned ranges, sufficient hole transport properties can be obtained without a substantial increase in driving voltage.

[0089] In addition to the materials described above, the hole transport region HTR may further include a charge-generating material to improve conductivity. The charge-generating material may be uniformly or non-uniformly dispersed within the hole transport region HTR. The charge-generating material may be, for example, a p-dopant. The p-dopant may be one of, but is not limited to, a quinone derivative, a metal oxide, or a cyano group-containing compound. Non-limiting examples of p-dopants include, but are not limited to, quinone derivatives such as TCNQ (tetracyanoquinodimethane) and F4-TCNQ (2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinodimethane), metal oxides such as tungsten oxide and molybdenum oxide.

[0090] As described above, the hole transport region HTR may further include at least one of a hole buffer layer (not shown) and an electron blocking layer EBL in addition to the hole injection layer HIL and the hole transport layer HTL. The hole buffer layer (not shown) compensates for the resonance distance depending on the wavelength of light emitted from the emitting layer EML to increase light emission efficiency. The material included in the hole buffer layer (not shown) may be the same as the material included in the hole transport region HTR. The electron blocking layer EBL serves to prevent electron injection from the electron transport region ETR to the hole transport region HTR. When the hole transport region HTR includes at least one of a hole buffer layer and an electron blocking layer adjacent to the emitting layer EML, the crosslinker compound according to an embodiment may be included in the hole buffer layer and / or the electron blocking layer adjacent to the emitting layer EML. Furthermore, the polymer compound according to an embodiment may be included in the hole buffer layer and / or the electron blocking layer adjacent to the emitting layer EML and be thermally crosslinked or hypercrosslinked by the crosslinker compound.

[0091] The emitting layer EML is provided on the hole transport region HTR. The emitting layer EML has a thickness of, for example, about 10 nm to about 100 nm, or about 10 nm to about 30 nm. The emitting layer EML has a single layer made of a single material, a single layer made of multiple different materials, or a multilayer structure having multiple layers made of multiple different materials.

[0092] The emitting layer EML of the organic electroluminescent device 10 may also emit blue light. For example, the emitting layer EML of the organic electroluminescent device 10 of one embodiment may emit blue light in the region of 490 nm or more. However, the embodiment is not limited thereto, and the emitting layer EML may also emit green light or red light.

[0093] Meanwhile, although not shown, the organic electroluminescent device 10 of one embodiment may include multiple light-emitting layers. The multiple light-emitting layers may be stacked sequentially, and for example, the organic electroluminescent device 10 including multiple light-emitting layers may emit white light. The organic electroluminescent device 10 including multiple light-emitting layers may have a tandem structure.

[0094] In one embodiment, the EML emitting layer is a delayed fluorescent emitting layer, a fluorescent emitting layer, a phosphorescent emitting layer, etc., and includes a known host material and dopant. For example, the EML emitting layer may emit thermally activated delayed fluorescence (TADF).

[0095] The host material of the emitting layer EML may be a known material, and is not particularly limited, and may be selected from fluoranthene derivatives, pyrene derivatives, arylacetylene derivatives, anthracene derivatives, fluorene derivatives, perylene derivatives, chrysene derivatives, etc. Preferred examples include pyrene derivatives, perylene derivatives, and anthracene derivatives. For example, the host material of the emitting layer EML may be an anthracene derivative represented by the following chemical formula 3: [ka] ...(chemical formula 3)

[0096] In Chemical Formula 3, R 31 ~R 40 are each independently a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted silyl group, a substituted or unsubstituted alkyl group having from 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms. 31 ~R 40 can bond with adjacent groups to form a ring.

[0097] In Chemical Formula 3, c and d each independently represent an integer of 0 or more and 5 or less.

[0098] Chemical Formula 3 may be represented by any one of Chemical Formulas 3-1 to 3-16 below. [ka] [ka] JPEG0007740893000027.jpg3754

[0099] In one embodiment, the emissive layer EML contains a host material selected from the group consisting of Alq3 (tris(8-hydroxyquinolino)aluminum), CBP (4,4'-bis(N-carbazolyl)-1,1'-biphenyl), PVK (poly(n-vinylcarbazole), ADN (9,10-di(naphthalen-2-yl)anthracene), TCTA (4,4',4"-tris(carbazol-9-yl)-triphenylamine), TPBi (1,3,5-tris(1-phenyl-1H-benzo[d]imidazol-2-yl)benzene), TBADN (3-tert-butyl-9,10-di(naphth-2-yl)anthracene), DSA (distyrylarylene), CDBP (4,4'-bis(9-carbazolyl)-2,2'-dimethyl-biphenyl), MADN (2-methyl-9,10-bis(naphthalene)), and the like. The delayed fluorescent host material may include, for example, 2,8-bis(diphenylphosphoryl)dibenzofuran, mCBP (3,3'-bis(N-carbazolyl)-1,1'-biphenyl), mCP (1,3-bis(N-carbazolyl)benzene), DNA (9,10-di(naphthalen-2-yl)anthracene), DPEPO (bis[2-(diphenylphosphino)phenyl]ether oxide), CP1 (hexaphenylcyclotriphosphazene), UGH2 (1,4-bis(triphenylsilyl)benzene), DPSiO3 (hexaphenylcyclotrisiloxane), DPSiO4 (octaphenylcyclotetrasiloxane), or PPF (2,8-bis(diphenylphosphoryl)dibenzofuran), mCBP (3,3'-bis(N-carbazolyl)-1,1'-biphenyl), mCP (1,3-bis(N-carbazolyl)benzene), or DNA (9,10-di(naphthalen-2-yl)anthracene). However, embodiments are not limited to these, and other known delayed fluorescent host materials may also be included in addition to the host materials listed above.

[0100] In one embodiment, the emitting layer EML includes, as a dopant, a styryl derivative (e.g., 1,4-bis[2-(3-N-ethylcarbazolyl)vinyl]benzene (BCzVB), 4-(di-p-tolylamino)-4′-[(di-p-tolylamino)styryl]stilbene (DPAVB), N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenamine (N-BDAVBi), perylene and its derivatives (e.g., 2,5,8,11-tetra-t-butylperylene (TBP)), pyrene and its derivatives (e.g., 1,1-dipyrene, 1,4-dipyrenylbenzene, 1,4-bis(N,N-diphenylamino)pyrene), or the like.

[0101] In one embodiment, the emitting layer EML may include two dopant materials having different lowest triplet excitation energy levels (T1 levels). In one embodiment, in the organic electroluminescent device 10, the emitting layer EML may include a host having a first lowest triplet excitation energy level, a first dopant having a second lowest triplet excitation energy level lower than the first lowest triplet excitation energy level, and a second dopant having a third lowest triplet excitation energy level lower than the second lowest triplet excitation energy level.

[0102] In one embodiment of the organic electroluminescent device 10 in which the emitting layer EML includes a host, a first dopant, and a second dopant, the first dopant may be a delayed fluorescent dopant and the second dopant may be a fluorescent dopant.

[0103] For example, when the emission layer EML of the organic electroluminescent device 10 according to an embodiment includes multiple dopants, the emission layer EML may include a first dopant and a second dopant that are different from each other. For example, when the emission layer EML emits blue light, the emission layer EML includes, as the first dopant, any of the compounds listed above as the dopants for the emission layer EML, and as the second dopant, any one selected from the group consisting of spiro-DPVBi, spiro-6P, DSB (distyrylbenzene), DSA (distyrylarylene), PFO (polyfluorene)-based polymers, and PPV (poly(p-phenylenevinylene))-based polymers. The second dopant may also be a metal complex such as (4,6-F2ppy)2Irpic, an organometallic complex, perylene, or a derivative thereof.

[0104] 1 to 3, the electron transport region ETR is provided on the emitting layer EML. The electron transport region ETR includes at least one of a hole blocking layer HBL, an electron transport layer ETL, and an electron injection layer EIL, but the embodiment is not limited thereto.

[0105] The electron transport region ETR has a single layer made of a single material, a single layer made of a plurality of different materials, or a multilayer structure having a plurality of layers made of a plurality of different materials.

[0106] 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 a single-layer structure consisting of an electron injection material and an electron transport material. The electron transport region ETR may also have a single-layer structure consisting of multiple different materials, such as an electron transport layer ETL / electron injection layer EIL or a hole blocking layer HBL / electron transport layer ETL / electron injection layer EIL stacked in this order from the light-emitting layer EML, but is not limited to these. The thickness of the electron transport region ETR may be, for example, about 100 nm to about 150 nm.

[0107] The electron transport region ETR can be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0108] When the electron transport region ETR includes an electron transport layer ETL, the electron transport region ETR may include an anthracene-based compound. However, the electron transport region is not limited thereto, and examples thereof include Alq3 (tris(8-hydroxyquinolinato)aluminum), 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-phenylbenzimidazolyl-1-ylphenyl)-9,10-dinaphthylanthracene, TPBi (1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen (4,7-diphenyl-1,10-phenanthroline), TAZ (3-(4-biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazine), and the like. The electron transport layer ETL may include an organic EL element such as a tert-butylphenyl-4H-triazole (NTAZ), a tert-butylphenyl-4H-triazole (4-naphthalen-1-yl)-3,5-diphenyl-4H-triazole (NTAZ), a tert-butylphenyl-4H-triazole (tBu-PBD), a tert-butylphenyl-1,3,4-oxadiazole (tBu-PBD), a tert-butylphenyl-5-(4-biphenylyl)-1,3,4-oxadiazole (tBu-PBD), a tert-butylphenyl-5-(4-biphenylyl)-1,3,4-oxadiazole (tBu-PBD), a tert-butylphenyl-4H-tri ...

[0109] When the electron transport region ETR includes an electron injection layer EIL, the electron transport region ETR may include, but is not limited to, metal halides such as LiF, NaCl, CsF, RbCl, RbI, and CuI; lanthanoid metals such as Yb; metal oxides such as LiO and BaO; or lithium quinolate (LiQ). The electron injection layer EIL may also include a mixture of an electron transport material and an insulating organometal salt. The organometal salt has an energy band gap of about 4 eV or more. For example, the organometal salt may include metal acetate, metal benzoate, metal acetoacetate, metal acetylacetonate, or metal stearate. The thickness of the electron injection layer EIL is about 0.1 nm to about 10 nm, or about 0.3 nm to about 9 nm. When the thickness of the electron injection layer EIL satisfies the above-mentioned range, sufficient electron injection characteristics can be obtained without a substantial increase in driving voltage.

[0110] The electron transport region ETR may include a hole-blocking layer HBL as described above. The hole-blocking layer HBL may include, for example, but is not limited to, at least one of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and Bphen (4,7-diphenyl-1,10-phenanthroline).

[0111] The second electrode EL2 is provided on the electron transport region ETR. The second electrode EL2 is a common electrode or a negative electrode. The second electrode EL2 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. If the second electrode EL2 is a transmissive electrode, the second electrode EL2 is made of a transparent metal oxide, such as ITO, IZO, ZnO, or ITZO.

[0112] If the second electrode EL2 is a semi-transmissive electrode or a reflective electrode, the second electrode EL2 contains Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, Yb, or a compound or mixture containing any of these (for example, an alloy of Ag and Mg). Alternatively, the second electrode EL2 may have a multi-layer structure including a reflective film or semi-transmissive film made of the above materials and a transparent conductive film made of ITO, IZO, ZnO, ITZO, or the like.

[0113] Although not shown, the second electrode EL2 may be coupled to an auxiliary electrode, which can reduce the resistance of the second electrode EL2.

[0114] Meanwhile, although not shown, the organic electroluminescent device 10 of one embodiment may further include a buffer layer between the emitting layer EML and the electron transport region ETR. The buffer layer adjusts the concentration of excitons generated from the emitting layer EML. For example, the buffer layer may include some of the materials of the emitting layer EML. The buffer layer may include the host material of the emitting layer EML. The lowest triplet excitation energy level of the buffer layer material is adjusted to be equal to or higher than the lowest triplet excitation energy level of the second dopant, depending on the combination of the host and dopant materials contained in the emitting layer EML.

[0115] In the organic electroluminescent device 10 according to one embodiment of the present invention, the crosslinker compound of the above-described embodiment is included in the hole transport region HTR disposed between the first electrode EL1 and the second electrode EL2, so that the hole transport region can be formed through a wet process such as inkjet printing, and the residual film characteristics of the hole transport region HTR are improved, thereby providing an organic electroluminescent device having high luminous efficiency and low driving voltage.

[0116] 4A to 4C are cross-sectional views schematically illustrating some steps in a method for manufacturing an organic electroluminescent device according to an embodiment of the present invention. FIGS. 4A to 4C sequentially illustrate steps for forming a hole transport layer HTL on a hole injection layer HIL in a method for manufacturing an organic electroluminescent device according to an embodiment of the present invention. Hereinafter, a method for manufacturing an organic electroluminescent device according to an embodiment of the present invention will be described with reference to FIGS. 4A to 4C.

[0117] A method for manufacturing an organic electroluminescent device according to one embodiment includes the steps of: providing a first electrode; forming a hole transport region by providing a hole transport material on the first electrode; forming a light-emitting layer on the hole transport region; and forming a second electrode on the light-emitting layer. Figures 4A to 4C show the steps of forming the hole transport region by providing a hole transport material on the first electrode.

[0118] 4A to 4C, the hole transport region HTR (see FIG. 1) includes a hole injection layer HIL formed on the first electrode EL1 and a hole transport layer HTL formed on the hole injection layer HIL, and the hole transport layer HTL is formed of a hole transport material HTM. The hole transport material HTM includes a crosslinker compound according to one embodiment. The hole transport material HTM includes a crosslinker compound represented by Chemical Formula 1 above. The hole transport material HTM further includes a polymer compound containing a substituted or unsubstituted triarylamino group, and the polymer compound is represented by Chemical Formula 2-1 or 2-2 above. In the hole transport material HTM, the weight ratio of the polymer compound to the crosslinker compound is about 4:1 to about 19:1. Preferably, in the hole transport material HTM, the weight ratio of the polymer compound to the crosslinker compound is about 9:1. The hole transport material HTM is prepared by mixing a polymer compound and a crosslinker compound in a solvent. In one embodiment, the solvent comprises toluene, xylene, o-xylene, m-xylene, or anisole, or a mixture of these solvents.

[0119] The hole transport material HTM is deposited on the hole injection layer HIL by a wet process. While Figure 4a illustrates an example in which the hole transport material HTM is deposited on the hole injection layer HIL through a nozzle NZ, the hole transport material HTM may be deposited by various methods, including, but not limited to, a solution process such as spin coating, inkjet printing, nozzle printing, or spray printing.

[0120] According to an embodiment, a method for manufacturing an organic electroluminescent device includes forming a preliminary hole transport layer (P-HTL) by disposing a hole transport material (HTM) on the hole injection layer (HIL), and then forming the hole transport layer (HTL) by applying heat or light to the preliminary hole transport layer (P-HTL). While FIG. 4B exemplarily illustrates the formation of the hole transport layer (HTL) by thermally crosslinking the polymer compound and crosslinker compound contained in the preliminary hole transport layer (P-HTL) (FIG. 4C), the hole transport layer (HTL) may also be formed by photo-crosslinking the polymer compound and crosslinker compound contained in the preliminary hole transport layer (P-HTL).

[0121] Hereinafter, a crosslinker compound, a polymer compound, and an organic electroluminescent device according to an embodiment of the present invention will be described in detail with reference to examples and comparative examples. Note that the examples below are merely illustrative examples to aid in understanding the present invention, and the scope of the present invention is not limited thereto. [Example]

[0122] 1. Synthesis of crosslinker compound First, the synthesis method of the crosslinker compound according to this embodiment will be described in detail by exemplifying the synthesis methods of Example Compounds 1 and 2. The synthesis method of the crosslinker compound described below is merely an example, and the synthesis method of the crosslinker compound according to the embodiment of the present invention is not limited to the following examples. The structures of Example Compounds 1 and 2 are shown below. [ka] (Example Compound 1) [ka] (Example Compound 2)

[0123] (1) Synthesis of Example Compound 1 Example compound 1 according to one embodiment was synthesized by the following method.

[0124] The chlorine atom of 1,6-dichlorohexa-1,3,5-triene was replaced with an azide group via nucleophilic substitution to obtain the final compound. 1,6-Dichlorohexa-1,3,5-triene (10.0 g, 0.067 mol) and sodium azide (10.5 g, 0.161 mol, 2.4 eq.) were dissolved in DMF solvent in a flask under nitrogen atmosphere and stirred at room temperature for 12 hours to synthesize Example Compound 1 in 95% yield.

[0125] (2) Synthesis of Example Compound 2 Example compound 2 according to one embodiment was synthesized by the following method.

[0126] The chlorine atom of 1,1,8,8-tetrachlorohexa-1,3,5-triene was replaced with an azide group via nucleophilic substitution to obtain the final compound. 1,1,8,8-tetrachlorohexa-1,3,5-triene (10.0 g, 0.040 mol) and sodium azide (12.5 g, 0.192 mol, 4.8 equivalents) were dissolved in DMF solvent in a nitrogen atmosphere flask and stirred at room temperature for 12 hours to synthesize Example Compound 2 in 89% yield.

[0127] 2. Preparation of polymer compounds Polymer compounds A to C were prepared along with the crosslinker compound according to this embodiment. Commercially available materials were used for polymer compounds A to C. The structures of polymer compounds A to C are shown below. In the following chemical formulas, q1 and q2 are each independently an integer of 10 or more and 50 or less. [ka] ...(High molecular compound A) [ka] ...(High molecular compound B) [ka] ...(High molecular compound C)

[0128] 3. Evaluation of film remaining rate characteristics The crosslinker compounds and polymer compounds of the examples and comparative examples were mixed to form inks, and then single films were formed using the inks, and the remaining film ratios of the single films were measured. The combinations of crosslinker compounds and polymer compounds used in each ink and the methods for producing the inks are shown below.

[0129] (Example Ink 1) Example compound 1 was used as the crosslinker compound, and polymer compound A was used as the polymer compound. Polymer compound A and example compound 1 were mixed in a weight ratio of 9:1, and then anisole was used as a solvent to prepare example ink 1 with a concentration of 1.5%.

[0130] (Example Ink 2) Example ink 2 having a concentration of 1.5% was prepared in the same manner as Example ink 1, except that Example compound 2 was used as the crosslinker compound.

[0131] (Example Ink 3) Example ink 3 having a concentration of 1.5% was prepared in the same manner as Example ink 1, except that polymer compound B was used as the polymer compound.

[0132] (Example Ink 4) Example ink 4 having a concentration of 1.5% was prepared in the same manner as Example ink 3, except that Example compound 2 was used as the crosslinker compound.

[0133] (Example Ink 5) Example ink 5 having a concentration of 1.5% was prepared in the same manner as Example ink 1, except that polymer compound C was used as the polymer compound.

[0134] (Example Ink 6) Example ink 6 having a concentration of 1.5% was prepared in the same manner as Example ink 5, except that Example compound 2 was used as the crosslinker compound.

[0135] (Comparative Ink 1) Comparative Example Compound 1 was used as the crosslinker compound, and Polymer Compound A was used as the polymer compound. Polymer Compound A and Comparative Example Compound 1 were mixed in a weight ratio of 9:1, and then anisole was used as a solvent to prepare Comparative Example Ink 1 with a concentration of 1.5%.

[0136] (Comparative Ink 2) Comparative ink 2 having a concentration of 1.5% was prepared in the same manner as comparative ink 1, except that polymer compound B was used as the polymer compound.

[0137] The structures of the compounds used in the manufacturing methods of each ink are as follows: [ka] (Example Compound 1) [ka] (Example Compound 2) [ka] ...(High molecular compound A) [ka] ...(High molecular compound B) [ka] ...(High molecular compound C) [ka] (Comparative Example Compound 1)

[0138] (Preparation of a single film and evaluation of the remaining film rate) The inks of the Examples and Comparative Examples prepared as described above were applied to form a 40 nm thick film, which was then dried at 200°C for 30 minutes to complete the preparation of a single film. The UV of the single film was measured first. Next, 50 μL of methyl benzoate was dropped onto the single film and left for 30 minutes, after which the solvent was absorbed using a wiper. The thin film was dried at 100°C for 1 minute, and the UV was measured secondarily. The remaining film rate of the single film was calculated using the following equation 1. Remaining film rate (%) = 2nd UV measurement area / 1st UV measurement area (Formula 1)

[0139] Table 1 shows the evaluation results of the remaining film ratios of the single films formed using Example Inks 1 to 6 and Comparative Example Inks 1 and 2. [Table 1]

[0140]

[0046] Referring to the results in Table 1, it can be seen that the single film formed using the crosslinker compound according to an embodiment of the present invention has a higher film retention rate than the single film formed using the crosslinker compound of the comparative example. The single film including the crosslinker compound according to an embodiment has improved film formability due to increased crosslinking efficiency by the crosslinker compound, thereby improving the film properties of the hole transport layer when forming the hole transport layer of an organic electroluminescent device. Furthermore, the crosslinker compound does not reduce the conjugation properties of the polymer compound having hole transport ability, making it possible to manufacture an organic electroluminescent device with high luminous efficiency and low driving voltage.

[0141] Although the present invention has been described above with reference to preferred embodiments, it will be understood by those skilled in the art or those with ordinary knowledge in the art that various modifications and variations of the present invention can be made without departing from the spirit and technical scope of the present invention as set forth in the claims below.

[0142] Therefore, the technical scope of the present invention should be determined by the claims, not by the contents described in the detailed description of the specification. [Explanation of symbols]

[0143] 10: Organic electroluminescent element EL1: First electrode EL2: Second electrode HTR: Hole transport region EML: Light-emitting layer ETR: Electron transport region HTM: Hole transport material

Claims

1. providing a first electrode; providing a hole transport material on the first electrode to form a hole transport region; forming a light-emitting layer over the hole transport region; and forming a second electrode on the light-emitting layer; The hole transport material comprises a crosslinker compound represented by the following Chemical Formula 1: 【Chemical 1】 ...(chemical formula 1) (In the above Chemical Formula 1, A is a hydrogen atom or a deuterium atom, m is an integer of 1 or more and 100 or less, L １ and L ２ each independently represents a direct bond or a substituted or unsubstituted methylene group, n １ and n ２ are each independently 1 or 2.

2. The hole transport region a hole injection layer disposed on the first electrode; a hole transport layer disposed on the hole injection layer; The method of claim 1 , wherein the hole transport layer is formed from the hole transport material.

3. The hole transport region comprising a plurality of organic layers; The method of claim 1 , wherein the organic layer adjacent to the light-emitting layer among the plurality of organic layers is formed of the hole transport material.

4. The method for manufacturing an organic electroluminescent device described in claim 1, wherein the crosslinker compound represented by chemical formula 1 is represented by the following chemical formula 1-1 or chemical formula 1-2. 【Chemistry 2】 ...(Chemical formula 1-1) 【Chemistry 3】 ...(Chemical formula 1-2) 5. The method for manufacturing an organic electroluminescent device according to claim 1, wherein the hole transport material further comprises a polymer compound containing a substituted or unsubstituted triarylamino group.

6. The method for manufacturing an organic electroluminescent device according to claim 5, wherein the polymer compound is represented by the following chemical formula 2-1 or 2-2. 【Chemistry 4】 ...(Chemical formula 2-1) 【Chemistry 5】 ...(Chemical formula 2-2) (In the above Chemical Formula 2-1 and Chemical Formula 2-2, R 1 to R 7 each independently represent a hydrogen atom, a deuterium atom, a halogen atom, a substituted or unsubstituted alkyl group having from 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having from 6 to 30 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having from 2 to 30 ring carbon atoms; a 1 is an integer of 0 to 5, a 2 and a 3 each independently represent an integer of 0 to 4, a 4 and a 5 each independently represent an integer of 0 to 3, p 1 and p 2 are each independently an integer of 1 or more and 100 or less.

7. The method for manufacturing an organic electroluminescent device according to claim 6, wherein the polymer compound is represented by the following chemical formula 2-1-1, chemical formula 2-1-2, or chemical formula 2-2-1. 【Chemistry 6】 ...(Chemical formula 2-1-1) 【Chemistry 7】 ...(Chemical formula 2-1-2) 【Chemistry 8】 ...(Chemical formula 2-2-1)

8. A method for manufacturing an organic electroluminescent element as described in Claim 5, wherein the weight ratio of the polymer compound and the crosslinker compound contained in the hole transport material is 4:1 to 19:

1.

9. A method for manufacturing an organic electroluminescent element as described in Claim 5, wherein when forming the hole transport region, the polymer compound is thermally crosslinked or photocrosslinked with the crosslinker compound.

10. A crosslinker compound represented by the following chemical formula 1. 【Chemistry 9】 ...(chemical formula 1) (In the above Chemical Formula 1, A is a hydrogen atom or a deuterium atom, m is an integer of 1 or more and 100 or less, L 1 and L 2 each independently represent a direct bond or a substituted or unsubstituted methylene group; n 1 and n 2 are each independently 1 or 2.

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