Organic light-emitting devices

Abstract

The present disclosure relates to organic light emitting devices with improved driving voltage, efficiency, and lifetime.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0009537 filed in the Korean Intellectual Property Office on January 23, 2020, and Korean Patent Application No. 10-2021-0002022 filed in the Korean Intellectual Property Office on January 7, 2021, the disclosures of which are incorporated herein by reference in their entirety.

[0003] The present disclosure relates to organic light emitting devices with improved driving voltage, efficiency, and lifetime. Background Art

[0004] Generally, the organic light emitting phenomenon refers to the phenomenon of converting electrical energy into light energy by using organic materials. Organic light emitting devices using the organic light emitting phenomenon have characteristics such as wide viewing angle, excellent contrast, fast response time, excellent brightness, driving voltage and response speed, and therefore many studies have been conducted.

[0005] An organic light-emitting device generally has a structure including an anode, a cathode, and an organic material layer between the anode and the cathode. The organic material layer often has a multilayer structure including different materials to improve the efficiency and stability of the organic light-emitting device. For example, the organic material layer may be formed of a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, etc. In the structure of the organic light-emitting device, if a voltage is applied between two electrodes, holes are injected from the anode into the organic material layer, and electrons are injected from the cathode into the organic material layer, and when the injected holes and electrons meet each other, excitons are formed, and light is emitted when the excitons fall back to the ground state again.

[0006] There is a continuing need to develop organic light emitting devices having improved driving voltage, efficiency, and lifetime.

[0007] [Prior art literature]

[0008] [Patent Document]

[0009] (Patent Document 1) Korean Unexamined Patent Publication No. 10-2000-0051826 Summary of the invention

[0010] Technical issues

[0011] The present disclosure relates to organic light emitting devices with improved driving voltage, efficiency, and lifetime.

[0012] Technical Solution

[0013] In the present disclosure, there is provided an organic light emitting device comprising:

[0014] anode;

[0015] cathode;

[0016] A light-emitting layer between the anode and cathode;

[0017] an electron blocking layer between the anode and the light-emitting layer, and

[0018] The hole transport layer between the electron blocking layer and the anode,

[0019] The hole transport layer comprises a compound represented by the following Chemical Formula 1,

[0020] and the electron blocking layer includes a compound represented by the following Chemical Formula 2,

[0021] [Chemical formula 1]

[0022]

[0023] In Chemical Formula 1,

[0024] R1 and R2 are each independently substituted or unsubstituted C 1-60 Alkyl, or substituted or unsubstituted C 6-60 Aryl;

[0025] Any one of R3 to R6 is bonded to the following Chemical Formula 3; and R3 to R6 not bonded to the following Chemical Formula 3 are each independently hydrogen or deuterium,

[0026] [Chemical formula 3]

[0027]

[0028] In chemical formula 3,

[0029] L1 is substituted or unsubstituted C 6-60 arylene;

[0030] Ar1 is substituted or unsubstituted C 1-60 Aryl,

[0031] The dotted line is bonded to any one of R3 to R6 of Chemical Formula 1, and

[0032] R7 to R 10 are each independently hydrogen, deuterium, or substituted or unsubstituted C 6-60 Aryl;

[0033] [Chemical formula 2]

[0034]

[0035] L2 and L3 are each independently a single bond, or a substituted or unsubstituted C 6-60 arylene;

[0036] Ar2 and Ar3 are each independently substituted or unsubstituted C 6-60 aryl, or a substituted or unsubstituted C 2-60 Heteroaryl,

[0037] Each R3 is independently hydrogen or deuterium; or two adjacent R3 are combined to form a benzene ring,

[0038] Each R4 is independently hydrogen or deuterium; or two adjacent R4 are combined to form a benzene ring,

[0039] m is an integer from 1 to 8,

[0040] n is an integer from 1 to 4, and

[0041] a and b are each independently an integer of 1 to 3.

[0042] Beneficial Effects

[0043] The above-mentioned organic light emitting device has improved driving voltage, efficiency and lifespan. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 An example of an organic light emitting device including a substrate 1, an anode 2, an electron blocking layer 3, a light emitting layer 4, a hole transport layer 5 and a cathode 6 is shown.

[0045] Figure 2 An example of an organic light-emitting device including a substrate 1, an anode 2, a hole injection layer 7, a hole transport layer 8, an electron blocking layer 3, a light-emitting layer 4, a hole blocking layer 9, a hole transport layer 5, an electron injection layer 10 and a cathode 6 is shown. DETAILED DESCRIPTION

[0046] Hereinafter, embodiments of the present disclosure will be described in more detail to facilitate understanding of the present invention.

[0047] As used in this article, the symbol or It refers to the bond to another substituent.

[0048] As used herein, the term "substituted or unsubstituted" means unsubstituted or substituted with one or more substituents selected from the following: deuterium; halogen group; nitrile group; nitro group; hydroxyl group; carbonyl group; ester group; imide group; amino group; phosphine oxide group; alkoxy group; aryloxy group; alkylthio group; arylthio group; alkylsulfonyl group; arylsulfonyl group; silyl group; boron group; alkyl group; cycloalkyl group; alkenyl group; aryl group; aralkyl group; aralkenyl group; alkylaryl group; alkylamino group; aralkylamino group; heteroarylamino group; arylamino group; arylphosphino group; and heterocyclic group containing at least one of N, O and S atoms, or unsubstituted or substituted with substituents in which two or more substituents are connected among the substituents exemplified above. For example, "a substituent in which two or more substituents are connected" can be a biphenyl group. That is, the biphenyl group can be an aryl group, or it can also be interpreted as a substituent in which two phenyl groups are connected.

[0049] In the present disclosure, the carbon number of the carbonyl group is not particularly limited, but is preferably 1 to 40. Specifically, the carbonyl group may be a group having the following structural formula, but is not limited thereto.

[0050]

[0051] In the present disclosure, the ester group may have a structure in which the oxygen of the ester group is substituted by a linear, branched, or cyclic alkyl group having 1 to 25 carbon atoms, or an aryl group having 6 to 25 carbon atoms. Specifically, the ester group may be a group having the following structural formula, but is not limited thereto.

[0052]

[0053] In the present disclosure, the carbon number of the imide group is not particularly limited, but is preferably 1 to 25. Specifically, the imide group may be a group having the following structural formula, but is not limited thereto.

[0054]

[0055] In the present disclosure, the silyl group specifically includes trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl and the like, but is not limited thereto.

[0056] In the present disclosure, the boryl group specifically includes trimethylboryl, triethylboryl, tert-butyldimethylboryl, triphenylboryl, phenylboryl, and the like, but is not limited thereto.

[0057] In the present disclosure, examples of halogen groups include fluorine, chlorine, bromine or iodine.

[0058] In the present disclosure, the alkyl group may be linear or branched, and its carbon number is not particularly limited, but is preferably 1 to 40. According to one embodiment, the carbon number of the alkyl group is 1 to 20. According to another embodiment, the carbon number of the alkyl group is 1 to 10. According to another embodiment, the carbon number of the alkyl group is 1 to 6. Specific examples of the alkyl group include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl and the like, but are not limited thereto.

[0059] In the present disclosure, the alkenyl group may be linear or branched, and the carbon number thereof is not particularly limited, but is preferably 2 to 40. According to one embodiment, the carbon number of the alkenyl group is 2 to 20. According to another embodiment, the carbon number of the alkenyl group is 2 to 10. According to another embodiment, the carbon number of the alkenyl group is 2 to 6. Specific examples thereof include vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1-butenyl, 1,3-butadienyl, aryl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl, 2,2-diphenylvinyl-1-yl, 2-phenyl-2-(naphthyl-1-yl)vinyl-1-yl, 2,2-bis(diphenyl-1-yl)vinyl-1-yl, stilbene, styryl, etc., but are not limited thereto.

[0060] In the present disclosure, the cycloalkyl group is not particularly limited, but its carbon number is preferably 3 to 60. According to one embodiment, the carbon number of the cycloalkyl group is 3 to 30. According to another embodiment, the carbon number of the cycloalkyl group is 3 to 20. According to another embodiment, the carbon number of the cycloalkyl group is 3 to 6. Specific examples thereof include cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, cyclooctyl and the like, but are not limited thereto.

[0061] In the present disclosure, the aryl group is not particularly limited, but its carbon number is preferably 6 to 60, and it may be a monocyclic aryl group or a polycyclic aryl group. According to one embodiment, the carbon number of the aryl group is 6 to 30. According to one embodiment, the carbon number of the aryl group is 6 to 20. The monocyclic aryl group includes phenyl, biphenyl, terphenyl, etc., but is not limited thereto. The polycyclic aryl group includes naphthyl, anthracenyl, phenanthrenyl, pyrenyl, peryl, fluorenyl, etc., but are not limited thereto.

[0062] In the present disclosure, the fluorenyl group may be substituted, and two substituents may be bonded to each other to form a spirocyclic structure. In the case where the fluorenyl group is substituted, etc. However, the structure is not limited thereto.

[0063] In the present disclosure, the heterocyclic group is a heterocyclic group containing at least one heteroatom selected from O, N, Si and S as a heteroelement, and the carbon number thereof is not particularly limited, but is preferably 2 to 60. Examples of the heterocyclic group include thienyl, furyl, pyrrolyl, imidazolyl, thiazolyl, Azolyl, oxadiazolyl, triazolyl, pyridinyl, bipyridyl, pyrimidinyl, triazinyl, triazolyl, acridinyl, pyridazinyl, pyrazinyl, quinolyl, quinazolinyl, quinoxalinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinolyl, indolyl, carbazolyl, benzo oxazolyl, benzimidazolyl, benzothiazolyl, benzocarbazolyl, benzothiophenyl, dibenzothiophenyl, benzofuranyl, phenanthroline, thiazolyl, isothiophene oxazolyl, thiadiazolyl, benzothiazolyl, phenothiazinyl, dibenzofuranyl and the like, but are not limited thereto.

[0064] In the present disclosure, the aryl in aralkyl, aralkenyl, alkylaryl and arylamine is the same as the aforementioned example of aryl. In the present disclosure, the alkyl in aralkyl, alkylaryl and alkylamine is the same as the aforementioned example of alkyl. In the present disclosure, the heteroaryl in heteroarylamine can apply the aforementioned description of heterocyclic group. In the present disclosure, the alkenyl in aralkenyl is the same as the aforementioned example of alkenyl. In the present disclosure, the aforementioned description of aryl can be applied, except that arylene is a divalent group. In the present disclosure, the aforementioned description of heterocyclic group can be applied, except that heteroarylene is a divalent group. In the present disclosure, the aforementioned description of aryl or cycloalkyl can be applied, except that the hydrocarbon ring is not a monovalent group but is formed by combining two substituents. In the present disclosure, the aforementioned description of heterocyclic group can be applied, except that the heterocyclic ring is not a monovalent group but is formed by combining two substituents.

[0065] Hereinafter, the organic light emitting device of the present disclosure will be described based on the above definitions.

[0066] The organic light emitting device of the present disclosure uses both the compound represented by Chemical Formula 1 as a material for a hole transport layer and the compound represented by Chemical Formula 2 as a material for an electron blocking layer.

[0067] Specifically, the compound represented by Chemical Formula 1 has a structure in which a biphenylfluorenyl-substituted amine is bonded to the 2-position of a fluorene-based core and a substituent (Ar1) such as an aryl group is bonded to the 7-position of the fluorene-based core.

[0068] In addition, the compound represented by Chemical Formula 2 has a monoamine structure in which biphenyl and carbazole as substituents are linked in an ortho direction.

[0069] Generally, there is a trade-off between luminous efficiency and lifespan. Considering this, the organic light-emitting device of the present disclosure is excellent in all aspects of driving voltage, luminous efficiency and lifespan compared to an organic light-emitting device containing only one or neither of the compounds represented by Chemical Formulae 1 and 2.

[0070] The organic light emitting device of the present disclosure will be described in detail with respect to each configuration.

[0071] Anode and cathode

[0072] Anode and cathode used in the present disclosure refer to electrodes used in an organic light emitting device.

[0073] As the anode material, it is generally preferred to use a material with a large work function so that holes can be smoothly injected into the organic material layer. Specific examples of anode materials include: metals such as vanadium, chromium, copper, zinc, and gold, or alloys thereof; metal oxides such as zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); combinations of metals and oxides such as ZnO:Al or SnO2:Sb; conductive polymers such as poly(3-methylthiophene), poly[3,4-(ethylene-1,2-dioxy)thiophene] (PEDOT), polypyrrole, and polyaniline; etc., but are not limited thereto.

[0074] As the cathode material, it is generally preferred to use a material having a small work function so that electrons can be easily injected into the organic material layer. Specific examples of cathode materials include: metals such as magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, gadolinium, aluminum, silver, tin, and lead, or alloys thereof; multilayer structure materials such as LiF / Al or LiO2 / Al; etc., but are not limited thereto.

[0075] Luminescent layer

[0076] The light emitting layer used in the present disclosure refers to a layer that emits light in the visible light region by combining holes and electrons transferred from an anode and a cathode. Generally, the light emitting layer includes a host material and a dopant material.

[0077] The host material may also include fused aromatic ring derivatives, heterocyclic compounds, etc. Specific examples of fused aromatic ring derivatives include anthracene derivatives, pyrene derivatives, naphthalene derivatives, pentacene derivatives, phenanthrene compounds, fluoranthene compounds, etc. Examples of heterocyclic compounds include carbazole derivatives, dibenzofuran derivatives, ladder-type furan compounds, pyrimidine derivatives, etc., but are not limited thereto.

[0078] The dopant material is not particularly limited as long as it is a material used for an organic light-emitting device. For example, the dopant material includes aromatic amine derivatives, styrylamine compounds, boron complexes, fluoranthene compounds, metal complexes, and the like. Specifically, the aromatic amine derivative is a substituted or unsubstituted fused aromatic ring derivative having an arylamino group, and examples thereof include pyrene, anthracene, Diindenopyrene, etc. The styrylamine compound is a compound in which at least one arylvinyl group is substituted in a substituted or unsubstituted arylamine, wherein one or two or more substituents selected from aryl, silyl, alkyl, cycloalkyl, and arylamino are substituted or unsubstituted. Specific examples thereof include styrylamine, styryldiamine, styryltriamine, styryltetramine, etc., but are not limited thereto. In addition, the metal complex includes iridium complex, platinum complex, etc., but are not limited thereto.

[0079] Hole transport layer

[0080] An organic light emitting device according to the present disclosure includes a hole transport layer between an electron blocking layer and an anode.

[0081] The hole transport layer is a layer that receives holes from the hole injection layer and transfers the holes to the light-emitting layer. The hole transport material is suitably a material having a large hole mobility, which can receive holes from the anode or the hole injection layer and transfer the holes to the light-emitting layer. In the present disclosure, a compound represented by Chemical Formula 1 is used as a material constituting the hole transport layer.

[0082] Preferably, R1 and R2 are each independently methyl or phenyl.

[0083] Preferably, R4 is bonded to Chemical Formula 3; and R3, R5 and R6 are all hydrogen.

[0084] Preferably, R9 is hydrogen or phenyl; and R7, R8 and R 10 All hydrogen.

[0085] Preferably, L1 is phenylene.

[0086] Preferably, Ar1 is phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, or triphenylene; and Ar1 is unsubstituted or substituted with at least one of phenyl, naphthyl, or phenanthryl.

[0087] Representative examples of the compound represented by Chemical Formula 1 are as follows:

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096] The compound represented by Chemical Formula 1 can be prepared by a preparation method such as the following Reaction Scheme 1-1 or 1-2.

[0097] [Reaction Scheme 1-1]

[0098]

[0099] [Reaction Scheme 1-2]

[0100]

[0101] In each of the above schemes, each substituent has the same definitions as described above.

[0102] However, the preparation method can be described more specifically in the following preparation examples.

[0103] Electron blocking layer

[0104] The organic light emitting device according to the present disclosure includes an electron blocking layer between the anode and the light emitting layer. Preferably, the electron blocking layer is included in contact with the anode side of the light emitting layer.

[0105] The electron blocking layer is used to improve the efficiency of the organic light emitting device by inhibiting electrons injected from the cathode from transferring to the anode without being recombined in the light emitting layer. In the present disclosure, the compound represented by Chemical Formula 2 is used as a material constituting the electron blocking layer.

[0106] Preferably, R4 is hydrogen.

[0107] Preferably, each R3 is independently hydrogen; or two adjacent R3 are combined to form a benzene ring. Specifically, Chemical Formula 2 is represented by any one of the following Chemical Formulas 2-1 to 2-4.

[0108] [Chemical formula 2-1]

[0109]

[0110] [Chemical formula 2-2]

[0111]

[0112] [Chemical formula 2-3]

[0113]

[0114] [Chemical formula 2-4]

[0115]

[0116] L2, L3, Ar2, Ar3, a and b have the same definitions as described above.

[0117] Preferably, L2 and L3 are each independently a single bond, a phenylene group, or a naphthalenediyl group; and L2 and L3 are each independently unsubstituted or substituted with at least one phenyl group.

[0118] Preferably, a and b are each independently 1 to 2.

[0119] Preferably, Ar2 and Ar3 are each independently phenyl, biphenyl, terphenyl, naphthyl, phenanthryl, dimethylfluorenyl, diphenylfluorenyl or triphenylene.

[0120] Representative examples of the compound represented by Chemical Formula 2 are as follows:

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135] The compound represented by Chemical Formula 2 can be prepared by a preparation method such as the following Reaction Scheme 2.

[0136] [Reaction Scheme 2]

[0137]

[0138] In the above reaction scheme, each substituent has the same definition as described above.

[0139] However, the preparation method can be described more specifically in the following preparation examples.

[0140] Hole injection layer

[0141] If necessary, the organic light emitting device according to the present disclosure may further include a hole injection layer between the anode and the hole transport layer.

[0142] The hole injection layer is a layer for injecting holes from the electrode, and the hole injection material is preferably a compound that can transport holes, thus having a hole injection effect in the anode and having an excellent hole injection effect on the light-emitting layer or the light-emitting material, preventing the excitons generated in the light-emitting layer from moving to the electron injection layer or the electron injection material, and being excellent in the ability to form a thin film. It is preferred that the HOMO (highest occupied molecular orbital) of the hole injection material is between the work function of the anode material and the HOMO of the surrounding organic material layer.

[0143] Specific examples of the hole injection material include metalloporphyrins, oligothiophenes, arylamine-based organic materials, hexanitrile hexaazatriphenylene-based organic materials, quinacridone-based organic materials, perylene-based organic materials, anthraquinone, polyaniline-based and polythiophene-based conductive polymers, etc., but are not limited thereto.

[0144] Hole blocking layer

[0145] If necessary, the organic light emitting device according to the present disclosure includes a hole blocking layer between the light emitting layer and the electron transport layer. Preferably, the hole blocking layer is included to contact the light emitting layer.

[0146] The hole blocking layer is used to improve the efficiency of the organic light-emitting device by inhibiting the holes injected from the anode from transferring to the cathode without recombination in the light-emitting layer. Specific examples of the hole blocking material include Oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, BCP, aluminum complexes, etc., but not limited thereto.

[0147] Electron transport layer

[0148] The organic light emitting device according to the present disclosure may include an electron transport layer between the light emitting layer and the cathode.

[0149] The electron transport layer is a layer that receives electrons from the cathode or the electron injection layer formed on the cathode and transports the electrons to the light-emitting layer, and can inhibit the transfer of holes in the light-emitting layer. The electron transport material is suitably a material that can well receive electrons from the cathode and transport the electrons to the light-emitting layer, and has a large electron mobility.

[0150] Specific examples of electron transport materials include Al complexes of 8-hydroxyquinoline; complexes containing Alq3; organic free radical compounds; hydroxyflavone-metal complexes, etc., but are not limited thereto. The electron transport layer can be used with any desired cathode material as used in the related art. In particular, suitable examples of cathode materials are typical materials with low work functions, followed by an aluminum layer or a silver layer. Specific examples thereof include cesium, barium, calcium, ytterbium and samarium, in each case followed by an aluminum layer or a silver layer.

[0151] Electron injection layer

[0152] If necessary, the organic light emitting device according to the present disclosure may further include an electron injection layer between the electron transport layer and the cathode.

[0153] The electron injection layer is a layer that injects electrons from the electrode, and the electron injection material is preferably a compound that can transport electrons, has the effect of injecting electrons from the cathode and the excellent effect of injecting electrons into the light-emitting layer or the light-emitting material, prevents the excitons generated by the light-emitting layer from moving to the hole injection layer, and is also excellent in the ability to form a thin film.

[0154] Specific examples of materials that can be used as the electron injection layer include fluorenone, anthraquinone dimethane, diphenoquinone, thiopyran dioxide, Azoles, Oxadiazole, triazole, imidazole, perylenetetracarboxylic acid, fluorenyl methane, anthrone, etc., and derivatives thereof; metal complex compounds; nitrogen-containing 5-membered ring derivatives; etc., but not limited thereto.

[0155] Examples of metal complex compounds include 8-hydroxyquinoline lithium, bis(8-hydroxyquinoline) zinc, bis(8-hydroxyquinoline) copper, bis(8-hydroxyquinoline) manganese, tris(8-hydroxyquinoline) aluminum, tris(2-methyl-8-hydroxyquinoline) aluminum, tris(8-hydroxyquinoline) gallium, bis(10-hydroxybenzo[h]quinoline) beryllium, bis(10-hydroxybenzo[h]quinoline) zinc, bis(2-methyl-8-quinoline) gallium chloride, bis(2-methyl-8-quinoline)(o-cresol) gallium, bis(2-methyl-8-quinoline)(1-naphthol) aluminum, bis(2-methyl-8-quinoline)(2-naphthol) gallium, and the like, but are not limited thereto.

[0156] Organic light-emitting devices

[0157] Figure 1 Schematic diagram of the structure of an organic light-emitting device according to the present disclosure. Figure 1 An example of an organic light emitting device including a substrate 1, an anode 2, an electron blocking layer 3, a light emitting layer 4, a hole transport layer 5 and a cathode 6 is shown.

[0158] also, Figure 2 The structure of the organic light emitting device further includes a hole injection layer 7 , a hole transport layer 8 , a hole blocking layer 9 and an electron injection layer 10 .

[0159] The organic light emitting device according to the present disclosure can be manufactured by sequentially laminating the above components. In this case, the organic light emitting device can be manufactured as follows: a metal, a conductive metal oxide or its alloy is deposited on a substrate using a PVD (physical vapor deposition) method (e.g., sputtering or electron beam evaporation method) to form an anode, the above-mentioned various layers are formed on the anode, and then a material that can be used as a cathode is deposited thereon. In addition to such a method, the organic light emitting device can also be manufactured by sequentially depositing the above-mentioned components from the cathode material to the anode material on a substrate in reverse order (WO2003 / 012890). In addition, the light emitting layer can be formed by a solution coating method and a vacuum deposition method using a host and a dopant. In this article, the solution coating method means spin coating, dip coating, scraping, inkjet printing, screen printing, spray coating, roller coating, etc., but is not limited to this.

[0160] Meanwhile, the organic light emitting device according to the present disclosure may be a front-side emission type, a rear-side emission type, or a double-side emission type according to the materials used.

[0161] Hereinafter, preferred embodiments are presented to help understand the present invention. However, these embodiments are given for illustrative purposes only and are not intended to limit the scope of the present disclosure.

[0162] Preparation Example 1: Preparation of Compound 1-1

[0163]

[0164] Under nitrogen atmosphere, 4-(4-chlorophenyl)-9,9-diphenyl-9H-fluorene (7.56 g, 19.29 mmol) and 9,9-dimethyl-N-phenyl-9H-fluorene-2-amine were completely dissolved in 220 mL of xylene in a 500 mL round-bottom flask, and NaOtBu (2.22 g, 23.14 mmol) was added thereto. Then, bis(tri-tert-butylphosphine)palladium (0) (0.10 g, 0.19 mmol) was added thereto, followed by heating and stirring for 4 hours. After the temperature was lowered to room temperature and the alkali was removed by filtration, the xylene was concentrated under reduced pressure and recrystallized with 180 mL of ethyl acetate to prepare compound 1-2 (10.12 g, yield: 78%).

[0165] MS[M+H] + =752

[0166] Preparation Example 2: Preparation of Compound 1-2

[0167]

[0168] Under a nitrogen atmosphere, 4-bromo-9,9-diphenyl-9H-fluorene (10.50 g, 22.06 mmol) and (2-([1,1'-biphenyl]-4-yl(9,9-dimethyl-9H-fluorene-2-yl)-amino)phenyl)boric acid (10.28 g, 46.32 mmol) were completely dissolved in 240 ml of tetrahydrofuran in a 500 ml round-bottom flask, and a 2M potassium carbonate aqueous solution (120 ml) was added thereto. Then, tetrakis(triphenylphosphine)palladium (0.76 g, 0.66 mmol) was added thereto, followed by heating and stirring for 4 hours. After lowering the temperature to room temperature and removing the water layer, drying was performed over anhydrous magnesium sulfate. Then, it was concentrated under reduced pressure and recrystallized with 210 ml of ethyl acetate to prepare compound 1-2 (9.24 g, 62%).

[0169] MS[M+H] + =754

[0170] Preparation Example 3: Preparation of Compound 1-3

[0171]

[0172] Under nitrogen atmosphere, 4-(4-chlorophenyl)-9,9-diphenyl-9H-fluorene (7.56 g, 19.29 mmol) and 9,9-dimethyl-N-(4-(naphthalene-1-yl)phenyl)-9H-fluorene-2-amine were completely dissolved in 220 mL of xylene in a 500 mL round-bottom flask, and NaOtBu (2.22 g, 23.14 mmol) was added thereto. Then, bis(tri-tert-butylphosphine)palladium(0) (0.10 g, 0.19 mmol) was added thereto, followed by heating and stirring for 4 hours. After the temperature was lowered to room temperature and the alkali was removed by filtration, the xylene was concentrated under reduced pressure and recrystallized with 180 mL of ethyl acetate to prepare compound 1-3 (10.12 g, yield: 78%).

[0173] MS[M+H] + =805

[0174] Preparation Example 4: Preparation of Compound 2-1

[0175]

[0176] Under a nitrogen atmosphere, N-(4-bromophenyl)-N-(4-(phenanthrene-9-yl)phenyl)-[1,1'-biphenyl]-4-amine (12.32 g, 20.50 mmol) and (2-(9H-carbazole-9-yl)phenyl)boric acid (6.47 g, 22.55 mmol) were completely dissolved in 240 ml of tetrahydrofuran in a 500 ml round-bottom flask, and a 2M potassium carbonate aqueous solution (120 ml) was added thereto. Then, tetrakis(triphenylphosphine)palladium (0.42 g, 0.37 mmol) was added thereto, followed by heating and stirring for 4 hours. After lowering the temperature to room temperature and removing the water layer, it was dried over anhydrous magnesium sulfate. Then, it was concentrated under reduced pressure and recrystallized with 350 ml of ethyl acetate to prepare compound 2-1 (11.29 g, 72%).

[0177] MS[M+H] + =765

[0178] Preparation Example 5: Preparation of Compound 2-2

[0179]

[0180] Under a nitrogen atmosphere, N-(4-bromophenyl)-N-(4-(naphthalene-1-yl)phenyl)-[1,1'-biphenyl]-4-amine (11.09 g, 19.25 mmol) and (2-(9H-carbazole-9-yl)phenyl)boric acid (6.08 g, 21.18 mmol) were completely dissolved in 240 ml of tetrahydrofuran in a 500 ml round-bottom flask, and a 2M potassium carbonate aqueous solution (120 ml) was added thereto. Then, tetrakis(triphenylphosphine)palladium (0.67 g, 0.58 mmol) was added thereto, followed by heating and stirring for 3 hours. After lowering the temperature to room temperature and removing the water layer, it was dried over anhydrous magnesium sulfate. Then, it was concentrated under reduced pressure and recrystallized with 250 ml of ethyl acetate to prepare compound 2-2 (8.88 g, 62%).

[0181] MS[M+H] + =689

[0182] Preparation Example 6: Preparation of Compound 2-3

[0183]

[0184] Under a nitrogen atmosphere, N-([1,1'-biphenyl]-3-yl)-N-(4-bromophenyl)-[1,1':4',1"-terphenyl]-4-amine (10.55 g, 19.11 mmol) and (2-(9H-carbazole-9-yl)phenyl)boric acid (6.03 g, 21.02 mmol) were completely dissolved in 240 ml of tetrahydrofuran in a 500 ml round-bottom flask, and a 2M potassium carbonate aqueous solution (120 ml) was added thereto. Then, tetrakis(triphenylphosphine)palladium (0.66 g, 0.57 mmol) was added thereto, followed by heating and stirring for 4 hours. After lowering the temperature to room temperature and removing the water layer, it was dried over anhydrous magnesium sulfate. Then, it was concentrated under reduced pressure and recrystallized with 280 ml of ethyl acetate to prepare compound 2-3 (9.07 g, 66%).

[0185] MS[M+H] + =715

[0186] Comparative Example 1

[0187] It is coated with a thickness of The ITO (indium tin oxide) of the glass substrate as the film is put into the distilled water dissolved with the detergent therein, and carry out ultrasonic cleaning.At this moment, use the product manufactured by Fischer Co. as a detergent, and use the distilled water filtered twice by the filter manufactured by Millipore Co. as distilled water.After ITO was cleaned for 30 minutes, distilled water was used to repeat ultrasonic cleaning twice for 10 minutes.After cleaning with distilled water, substrate was ultrasonically cleaned with isopropyl alcohol, acetone and methanol solvent, dried, and then transferred to a plasma cleaner.In addition, oxygen plasma was used to clean substrate for 5 minutes, and then transferred to a vacuum deposition device.

[0188] The following compound HI-1 and the following compound HI-2 were deposited on the prepared ITO transparent electrode at a ratio of 98:2 (molar ratio) by thermal vacuum deposition. A hole injection layer is formed with a thickness of .

[0189] The following compound HT-1 as a material for transporting holes was vacuum deposited on the hole injection layer. To form a hole transport layer.

[0190] Then, the following compound EB-1 was vacuum deposited onto the hole transport layer. to form an electron blocking layer.

[0191] Then, a compound represented by the following chemical formula BH-1 and a compound represented by the following chemical formula BD-1 were vacuum deposited on the electron blocking layer at a weight ratio of 25:1. The following compound HB-1 was vacuum deposited on the light-emitting layer to form a light-emitting layer. A hole blocking layer is formed with a thickness of .

[0192] Then, the following compound ET-1 and the following compound LiQ (lithium quinoline) were vacuum deposited on the hole blocking layer at a weight ratio of 1:1. To form an electron transport layer, lithium fluoride (LiF) and aluminum are sequentially deposited on the electron transport layer to a thickness of 100 Å and 200 Å, respectively. and To form an electron injection layer and a cathode.

[0193] In the above process, the deposition rate of organic material is kept at / second to / sec, keeping the deposition rate of lithium fluoride at the cathode at / sec, and the aluminum deposition rate was maintained at / sec. In addition, the vacuum degree during deposition was maintained at 2 × 10 -7 Up to 5×10 -6Support, thereby manufacturing an organic light-emitting device.

[0194] The compounds used in Comparative Example 1 are as follows.

[0195]

[0196] Examples 1 to 9 and Comparative Examples 2 to 12

[0197] Organic light emitting devices of Examples 1 to 9 and Comparative Examples 2 to 12 were respectively manufactured in the same manner as in Comparative Example 1, except that the electron blocking compound EB-1 and the hole transport compound HT-1 were changed as shown in Table 1 below.

[0198] The compounds used to make each organic light-emitting device are as follows:

[0199]

[0200] Experimental example

[0201] By applying 20 mA / cm 2 The current is measured at 20mA / cm 2 The driving voltage, luminous efficiency and chromaticity coordinates at a current density of 20 mA / cm 2 The results are shown in Table 1 below. T95 means the time taken until the initial brightness (1600 nits) is reduced to 95%.

[0202] [Table 1]

[0203]

[0204] As shown in Table 1, the organic light-emitting device of the embodiment in which the compound represented by Chemical Formula 1 is used as a material for a hole transport layer and the compound represented by Chemical Formula 2 is used as a material for an electron blocking layer is excellent in all aspects of driving voltage, luminous efficiency and lifespan, compared with an organic light-emitting device containing only one of the compounds represented by Chemical Formulas 1 and 2 or neither.

[0205] It is determined that the driving voltage, luminous efficiency and especially the life span of the blue organic light-emitting device of the present disclosure manufactured by using the compound of Chemical Formula 1 (having a structure in which the amine substituted by biphenylfluorenyl is bonded to the 2-position of the fluorene-based core and the substituent (Ar1) such as an aryl group is bonded to the 7-position of the fluorene-based core) as a material for the hole transport layer (HTL) and using the compound of Chemical Formula 2 (having a monoamine structure in which biphenyl and carbazole as substituents are connected in the ortho direction) as a material for the electron blocking layer (EBL) can be improved. Generally, there is a trade-off relationship between luminous efficiency and life span. In view of this, it can be determined that the organic light-emitting device using the combination of the compounds of the present disclosure exhibits significantly improved device characteristics compared to the device of the comparative example.

[0206] [Explanation of Reference Numerals]

[0207] 1: Substrate 2: Anode

[0208] 3: Electron blocking layer 4: Light-emitting layer

[0209] 5: Hole transport layer 6: Cathode

[0210] 7: Hole injection layer 8: Hole transport layer

[0211] 9: Hole blocking layer 10: Electron injection layer

Claims

1. An organic light-emitting device, comprising: anode; cathode, a light-emitting layer between the anode and the cathode; an electron blocking layer between the anode and the light-emitting layer; and a hole transport layer between the electron blocking layer and the anode, The hole transport layer comprises a compound represented by the following Chemical Formula 1, and the electron blocking layer comprises a compound represented by the following Chemical Formula 2-1: [Chemical formula 1] In Chemical Formula 1, R1 and R2 are each methyl; R4 is bonded to the following chemical formula 3; and R3, R5 and R6 are each hydrogen, [Chemical formula 3] In the chemical formula 3, L1 is phenylene; Ar1 is phenyl or biphenyl, said Ar1 is unsubstituted or substituted by naphthyl, The dotted line is bonded to R4 of the chemical formula 1, and R7 to R 10 Each is hydrogen; [Chemical formula 2-1] L2 and L3 are each independently a single bond or a phenylene group; Ar2 and Ar3 are each independently phenyl, biphenyl, terphenyl, naphthyl or phenanthryl, and a and b are each 1.

2. The organic light emitting device according to claim 1, wherein The chemical formula 1 is any one selected from the following compounds:

3. The organic light-emitting device according to claim 1, wherein the chemical formula 2-1 is any one selected from the following compounds:

Images