KR20210019180A - Organic materials and organic light emitting diode having the same - Google Patents

Abstract

The present invention relates to a compound for an organic light emitting diode, the organic light emitting diode using same, and an electronic device comprising the organic light emitting diode. According to the present invention, it is possible to realize delayed fluorescence. In addition, the quantum efficiency of the organic light emitting diode is improved since radiationless decay is reduced due to a robust molecular structure. Moreover, the high glass transition temperature and the stability of molecules are enhanced, so that the lifespan can be improved.

Description

Organic materials and organic light-emitting diodes containing them {ORGANIC MATERIALS AND ORGANIC LIGHT EMITTING DIODE HAVING THE SAME}

The present invention relates to a compound for an organic light emitting diode, and more particularly, to a delayed fluorescent light emitting material.

In general, the organic light emission phenomenon refers to a phenomenon in which electrical energy is converted into light energy using an organic material. An organic light-emitting diode using an organic light-emitting phenomenon usually has a structure including an anode, a cathode, and an organic layer therebetween. Here, the organic layer is often made of a multilayer structure composed of different materials to increase the efficiency and stability of the organic light emitting device.For example, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, etc. Can be made.

Materials used as an organic layer in an organic light-emitting diode can be classified into light-emitting materials and charge transport materials, such as hole injection materials, hole transport materials, electron transport materials, and electron injection materials, according to their functions. In addition, the light-emitting material may be classified into a high molecular type and a low molecular type according to its molecular weight, and according to a light emitting mechanism, it may be classified into a fluorescent material derived from the singlet excited state of the electron and a phosphorescent material derived from the triplet excited state of the electron have. In addition, the light-emitting material may be classified into blue, green, and red light-emitting materials and yellow and orange light-emitting materials necessary for realizing a better natural color according to the light-emitting color.

Organic light-emitting diodes are self-luminous devices and are used in displays or lighting. Recently, organic light-emitting diodes have been applied to display panels. Compared to conventional liquid crystal displays, organic light-emitting diodes have a wide viewing angle and excellent contrast, as well as a quick response time, excellent luminance, driving voltage, and response speed characteristics, and are capable of multicolorization. Have.

These organic light-emitting diodes operate in direct current, and when a direct voltage is applied between the anode and the cathode, holes injected from the anode move to the emission layer via the hole injection/transport layer, and electrons injected from the cathode pass through the electron injection/transport layer. It moves to the emitting layer. Holes and electrons that reach the emission layer generate excitons in an excited state through recombination, and when the excitons change to a ground state, light of a specific wavelength is emitted.

In the formation of excitons, 25% of singlet states are generated according to the law of quantum spin statistics, and 75% of triplet states are formed. Light-emitting materials can be largely divided into fluorescent materials and phosphorescent materials, and since fluorescent materials use only a singlet state to emit light, theoretically, quantum efficiency is very low. Therefore, in order to improve the efficiency of the emission layer or the organic light emitting diode, triplet excitons should be utilized to the maximum.

Therefore, in the case of a phosphorescent material in which a heavy metal such as iridium (Ir) or platinum (Pt) is introduced, triplet excitons can be converted into light, and thus a highly efficient organic light emitting diode device can be manufactured. However, the cost of iridium (Ir) or platinum (Pt) is expensive, and the supply of materials is limited. In particular, in the case of blue phosphorescent materials, the device lifetime problem must be solved.

In order to solve the problem of the phosphorescent material, a thermally active delayed fluorescence technique may be used, and efficient thermally active delayed fluorescence materials may exhibit quantum efficiency characteristics of phosphorescence level. Thermally activated delayed fluorescence can convert excitons in a triplet state into excitons in a singlet state using thermal energy. In order to utilize the thermally activated delayed fluorescence mechanism, there are prerequisites that the light emitting material must have. That is, the energy difference between singlet and triplet states must be as small as 0.3 eV or less so that the inverse phase transition can occur due to room temperature or heat generated during device operation.

In order to reduce the energy difference between the singlet and triplet states, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital function (HOMO) and the lowest unoccupied molecular orbital function are minimized by minimizing the interaction between the intramolecular donor and acceptor units. Orbital, LUMO) should be designed to be able to separate well. In addition, it has the advantage of molecular design that can emit blue, green and red light by appropriately controlling the intensity between the donor molecule and the acceptor molecule.

Accordingly, the present inventors studied to provide a new design of thermally active delayed fluorescent material that does not use a rare metal used in the existing phosphorescent material. As a result, by properly combining donor and acceptor molecules based on triazole, The present invention was derived through a three-dimensional structure.

An object of the present invention is to provide an organic material with improved efficiency and improved life, and an organic light-emitting diode containing the same. In addition, it aims to improve the color purity and lifetime characteristics of blue, green, and red light emitting materials that can be applied to displays.

In one aspect, the present invention provides a compound represented by the following formula.

<Formula 1>

In another aspect, the present invention provides an organic light emitting diode using the compound represented by the above formula and an electronic device thereof.

In the compound according to the present invention, by performing effective HOMO-LUMO separation, charge transfer absorption and light emission forms are formed in the molecular structure, and a difference between singlet energy and triplet energy, that is, a narrow ΔEst may appear. Therefore, the organic material is capable of implementing delayed fluorescence, and its robust molecular structure reduces non-radiation attenuation, thereby improving the quantum efficiency of the organic light-emitting diode, and improving the lifetime of the organic light-emitting diode by enhancing high glass transition ionicity and molecular stability. It works.

1 is a cross-sectional view showing an organic light emitting diode according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

In order to describe the present embodiments, in adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible even if they are indicated on different drawings.

In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the subject matter of the present invention, a detailed description thereof will be omitted. In the drawings referred to below, the accumulation ratio is not applied.

In describing the constituent elements of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, order, or order of the component is not limited by the term.

When a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected or connected to that other component, but another component between each component It should be understood that elements may be “connected”, “coupled” or “connected”.

In addition, when a component such as a layer, film, region, or plate is said to be "on" or "on" another component, it is not only "directly over" another component, as well as another component in the middle. It should be understood that cases may also be included. Conversely, it should be understood that when an element is "directly above" another part, it means that there is no other part in the middle.

Terms used in the present specification and the appended claims are as follows, unless otherwise stated, without departing from the spirit of the present invention.

The term "halo" or "halogen" as used in this application includes fluorine (F), chlorine (Cl), bromine (Br), and iodine (I) unless otherwise specified.

The term "alkyl" or "alkyl group" as used in the present application has 1 to 60 carbons connected by a single bond unless otherwise specified, and a straight-chain alkyl group, a branched-chain alkyl group, a cycloalkyl (alicyclic) group, an alkyl-substituted It means a radical of a saturated aliphatic functional group including a cycloalkyl group and a cycloalkyl-substituted alkyl group. In addition, it may be used including "alkenyl" or "alkynyl" below.

The terms "alkenyl" or "alkynyl" as used in the present application are each having a double bond or a triple bond in place of a single bond in the above "alkyl" unless otherwise specified, and includes a straight or branched chain group, 2 It has a carbon number of to 60, but is not limited thereto.

The term "cycloalkyl" as used in the present application means an alkyl forming a ring having 3 to 60 carbon atoms unless otherwise specified, and is not limited thereto.

The terms "aryl group" and "arylene group" as used in the present application each have 6 to 60 carbon atoms, but are not limited thereto. In the present application, the aryl group or the arylene group includes a single cyclic type, a ring aggregate, and several cyclic compounds conjugated. For example, the aryl group may include a phenyl group, a biphenyl monovalent functional group, a naphthalene monovalent functional group, a fluorenyl group, and a substituted fluorenyl group, and the arylene group may include a fluorenylene group, a substituted fluorenylene group It may contain a group.

In the present application, since the aryl group includes a ring aggregate, the aryl group includes biphenyl and terphenyl in which the benzene ring, which is a single aromatic ring, is connected by a single bond.

The term "conjugated multiple ring systems" as used in the present application refers to a fused ring form that shares at least two atoms, and includes a form in which a ring system of two or more hydrocarbons is fused and at least one heteroatom And at least one conjugated heterocyclic system. Several such fused ring systems may be an aromatic ring, a heteroaromatic ring, an aliphatic ring, or a combination of these rings.

The term "heterocyclic group" used in the present application includes not only an aromatic ring such as a "heteroaryl group" or a "heteroarylene group", but also a non-aromatic ring, and unless otherwise stated, each carbon number including one or more heteroatoms It means a ring of 2 to 60, but is not limited thereto. The term "heteroatom" used in the present application represents N, O, S, P, or Se unless otherwise specified, and the heterocyclic group includes a monocyclic type including a heteroatom, a ring aggregate, a conjugated ring system, etc. it means.

In addition, unless explicitly stated otherwise, the term "substituted or unsubstituted" used in the present application "substituted" refers to hydrogen, deuterium, a C ₁ -C ₉ alkyl group, a C ₃ -C ₃₀ cycloalkyl group, a C _6- C ₃₀ aryl group, C ₈ -C ₃₀ alkylaryl group, C ₈ -C ₃₀ arylalkyl group, C ₂ -C ₃₀ heteroaryl group, aryloxy group, arylamine, conjugated arylamine group, phosphine Or it means substituted with one or more substituents selected from the group consisting of a phosphine oxide group, a thiol group, a sulfoxide or a sulfone group, and is not limited to these substituents.

In the present application, the'functional group name' corresponding to the aryl group, arylene group, heterocyclic group, etc. exemplified as examples of each symbol and its substituent may describe the'name of the functional group reflecting the number', but it is described as the'parent compound name' You may.

Hereinafter, a laminated structure of an organic light emitting diode containing the compound of the present invention will be described with reference to FIG. 1.

Referring to FIG. 1, referring to FIG. 1, an organic light emitting diode is disposed between an anode 10 and a cathode 70, a light emitting layer 40 disposed between these two electrodes, and an anode 10 and a light emitting layer 40. A hole conductive layer 20 and an electron conductive layer 50 disposed between the emission layer 40 and the cathode 70 are provided.

The hole conducting layer 20 may include a hole transport layer 25 for transporting holes and a hole injection layer 23 for facilitating injection of holes. Further, the electron conductive layer 50 may include an electron transport layer 55 for transporting electrons and an electron injection layer 53 for facilitating injection of electrons.

In addition, a first exciton blocking layer (not shown) may be disposed between the light emitting layer 40 and the hole transport layer 25. In addition, a second exciton blocking layer (not shown) may be disposed between the emission layer 40 and the electron transport layer 55. In addition, however, the present invention is not limited thereto, and the electron transport layer 55 may serve as a second exciton blocking layer, or the hole transport layer 25 may serve as a first electron blocking layer.

When a forward bias is applied to the organic light emitting diode, holes flow into the emission layer 40 from the anode 10 and electrons flow into the emission layer 40 from the cathode 70. Electrons and holes introduced into the emission layer 40 are combined to form excitons, and light is emitted while the excitons transition to a ground state.

The light emitting layer 40 may be formed of a single light emitting material, and may include a light emitting host material and a light emitting dopant material. When the light-emitting layer 40 includes a light-emitting host material and a light-emitting dopant material, electrons and holes introduced into the light-emitting layer 40 are combined in the light-emitting host material to form excitons, and the excitons are then transferred to the light-emitting dopant material to form a base. Can be transitioned to a state. The light emitting layer 40 including the light emitting host material and the light emitting dopant material may be a phosphorescent light emitting layer or a fluorescent light emitting layer, for example, a delayed fluorescent light emitting layer.

Any one of the compounds according to the present invention may be used for any one of the organic layers 20, 40, 50 of the organic light-emitting diode. Specifically, the compound may be used as any one of a hole injection material, a hole transport material, an exciton blocking material, a light emitting host material, a light emitting dopant material, an electron injection material, and an electron transport material. Specifically, the organic material may be used as a light-emitting dopant material, and in this case, the light-emitting layer 40 may be a delayed fluorescent light-emitting layer.

In addition, the organic material may be used as a sensor for a general fluorescent dopant. In this case, the emission layer may be an emission layer composed of a delayed fluorescent host and a fluorescent dopant.

In addition, the host of the emission layer 40 is mCP (N,N-dicarbazolyl-3,5-benzene), TSPO1 (diphenylphosphine oxide-4-(triphenylsilyl)phenyl), DPEPO (bis[2-(diphenylphosphino)phenyl]ether oxide) ), BSB (4,4′-bistriphenylsilanyl-biphenyl), UGH3 (m-bis- (triphenylsilyl)benzene), SimCP(3,5-di(N-carbazolyl)tetraphenylsilane), SimCP2 (bis(3,5-di (9H-carbazol-9-yl)phenyl)diphenylsilane), CzSi(9-(4-tertbutylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole), SiCa(Diphenyldi(4-(9-carbazoly)phenyl) )silane), DCPPO((3,5-di(9H-carbazole-9-yl)phenyl)diphenylphosphine oxide), DFCz (2,8-di(9Hcarbazol-9-yl)dibenzo[b,d]furan), DBT1(2,8-di(9H-carbazol-9-yl)dibenzo[b,d]thiophene), 26mCPy (2,6-bis(N-carbazolyl)pyridine), or a mixture of two or more thereof.

In addition, the host is Alq3, CBP (4,4'-N,N'-dicarbazole-biphenyl), 9,10-di (naphthalen-2-yl) anthracene, TPBI (1,3,5-tris ( N-phenylbenzimidazol-2-yl)benzene (1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene)), TBADN(3-tert-butyl-9,10-di(naphth- 2-day) anthracene).

The anode 10 may be a conductive metal oxide, a metal, a metal alloy, or a carbon material. Conductive metal oxides include indium tin oxide (ITO), fluorine tin oxide (FTO), antimony tin oxide (ATO), fluorine dope tin oxide (FTO), SnO ₂ , ZnO, Or it may be a combination of these. Metals or metal alloys suitable as the anode 10 may be Au and CuI. The carbon material may be graphite, graphene, or carbon nanotubes.

The hole injection layer 23 and/or the hole transport layer 25 are layers having a HOMO level between the work function level of the anode 10 and the HOMO level of the emission layer 40, and from the anode 10 to the emission layer 40 It functions to increase the efficiency of injection or transport of holes. In addition, the electron injection layer 53 and/or the electron transport layer 55 are layers having an LUMO level between the work function level of the cathode 70 and the LUMO level of the light emitting layer 40, and the light emitting layer 40 in the cathode 70 ) To increase the injection or transport efficiency of electrons.

The hole injection layer 23 or the hole transport layer 25 may include a material commonly used as a hole transport material, and one layer may include different hole transport material layers.

The hole transport material is, for example, mCP (N,N-dicarbazolyl-3,5-benzene); PEDOT:PSS (poly(3,4-ethylenedioxythiophene):polystyrenesulfonate); NPD (N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine); N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diaminobiphenyl (TPD); N,N'-diphenyl-N,N'-dinaphthyl-4,4'-diaminobiphenyl; N,N,N'N'-tetra-p-tolyl-4,4'-diaminobiphenyl; N,N,N'N'-tetraphenyl-4,4'-diaminobiphenyl; Porphyrin compound derivatives such as copper(II)1,10,15,20-tetraphenyl-21H,23H-porphyrin; TAPC (1,1-Bis[4-[N,N'-Di(ptolyl)Amino]Phenyl]Cyclohexane); Triarylamine derivatives such as N,N,N-tri(p-tolyl)amine, 4, 4', 4'-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine; Carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole; Phthalocyanine derivatives such as metal-free phthalocyanine and copper phthalocyanine; Starburst amine derivatives; Enaminestilbene derivatives; Derivatives of aromatic tertiary amines and styryl amine compounds; And polysilane. Such a hole transport material may serve as a first exciton blocking layer.

The second exciton blocking layer serves to prevent diffusion of triplet excitons or holes in the cathode 70 direction, and may be arbitrarily selected from known hole blocking materials. For example, oxadiazole derivatives, triazole derivatives, phenanthroline derivatives, and the like can be used.

The electron transport layer 55 is TSPO1 (diphenylphosphine oxide-4-(triphenylsilyl)phenyl), TPBi (1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene), tris(8-quinolinorate) )Aluminum (Alq3), 2,5-diaryl silol derivatives (PyPySPyPy), perfluorinated compounds (PF-6P), COTs (Octasubstituted cyclooctatetraene), Bphen (4,7-diphenyl-1,10-phenanthrol) It may be lean (4,7-diphenyl-1,10-phenanthroline)).

The electron injection layer 53 may be, for example, LiF, NaCl, CsF, Li2O, BaO, BaF2, or Liq (lithium quinolate). The cathode 70 is a conductive film having a lower work function than the anode 10, for example, metals such as aluminum, magnesium, calcium, sodium, potassium, indium, yttrium, lithium, silver, lead, cesium, etc. It can be formed using a combination of two or more types of.

The anode 10 and the cathode 70 may be formed using a sputtering method, a vapor deposition method, or an ion beam deposition method. The hole injection layer 23, the hole transport layer 25, the light emitting layer 40, the exciton blocking layer, the electron transport layer 55, and the electron injection layer 53 are independent of each other by a deposition method or a coating method, for example spraying. , Spin coating, dipping, printing, doctor blading, or an electrophoresis method. The scope of the present invention is not limited by this formation method.

The organic light emitting diode may be disposed on a substrate (not shown), and the substrate may be disposed under the anode 10 or over the cathode 70. In other words, the anode 10 may be formed earlier than the cathode 70 on the substrate or the cathode 70 may be formed before the anode 10.

The substrate may be a light-transmitting substrate as a flat member, and in this case, the substrate is glass; Ceramic materials; It may be made of a polymer material such as polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), and polypropylene (PP). However, the present invention is not limited thereto, and the substrate may be a metal substrate capable of light reflection.

The organic light emitting diode according to FIG. 1 may further include a protective layer (not shown) and an encapsulation layer (not shown). The protective layer may be disposed on the capping layer, and the encapsulation layer may be disposed on the capping layer, and may be formed to cover side portions of at least one of the anode, the cathode, and the organic layer to protect the anode, the cathode, and the organic layer.

The protective layer may provide a flattened surface so that the encapsulation layer can be uniformly formed, and may serve to protect the first electrode, the second electrode, and the organic layer in the manufacturing process of the encapsulation layer.

The encapsulation layer may play a role of preventing external oxygen and moisture from penetrating into the organic light emitting diode.

The organic light-emitting diode according to an embodiment of the present invention may be a top emission type, a bottom emission type, or a double-sided emission type depending on the material used.

Another embodiment of the present invention may include a display device including the organic light emitting diode of the present invention described above, and an electronic device including a controller for controlling the display device.

Hereinafter, a compound according to an aspect of the present invention will be described.

A compound according to an aspect of the present invention is represented by the following formula (1).

<Formula 1>

In Formula 1, each symbol may be defined as follows.

Ar ¹ is independently a single bond or a substituted or unsubstituted aryl group; A substituted or unsubstituted heteroaryl group; An alkyl group or aryl group in which the heterocyclic compound is substituted; Substituted or unsubstituted carbazole, fluorene, dibenzofuran or dibenzothiophene; Carbazole, fluorene, dibenzofuran or dibenzothiophene is a substituted alkyl group or aryl group,

Ar ^{2 to 3} are each independently halogen; Cyano group; An isocyanate group; Nitro group; Carbonyl group; Sulfoxide group; Sulfone group; Phosphite group; Phosphate group; Phosphine oxide group; A halogen element and a cyano group, an isocyanate group, a nitro group, a carbonyl group, a sulfoxide group, a sulfone group, a phosphite group, a phosphide group, or an alkyl group substituted with a phosphine oxide group, or a substituted or unsubstituted aryl group; A substituted or unsubstituted heteroaryl group; An alkyl group or aryl group in which the heterocyclic compound is substituted; Substituted or unsubstituted carbazole, fluorene, dibenzofuran or dibenzothiophene; Carbazole, fluorene, dibenzofuran or dibenzothiophene substituted alkyl or aryl group; is selected from the group consisting of,

Ar ^{4 to 5} are each independently alkoxy; Aryloxy; Aryl group; Alkylaryl group; Or an alkyl or aryl group substituted with an alkoxy group, an aryloxy group, an aryl group or an alkylaryl group; Alternatively, groups adjacent to each other may form a ring.

The compound represented by Formula 1 may be one of the following compounds, but is not limited thereto.

In another embodiment of the present invention, the present invention provides a first electrode; A second electrode; And an organic layer formed between the first electrode and the second electrode, wherein the organic layer includes a compound represented by Formula 1 alone or in combination.

The organic layer includes at least one of a hole injection layer, a hole transport layer, an exciton blocking layer, a light emitting layer, an electron transport auxiliary layer, an electron transport layer, and an electron injection layer. That is, at least one of a hole injection layer, a hole transport layer, an exciton blocking layer, a light emitting layer, an electron transport auxiliary layer, an electron transport layer, or an electron injection layer included in the organic layer may include a compound represented by Formula 1.

Preferably, the organic layer includes the emission layer or the exciton blocking layer. That is, the compound may be included in the emission layer or the exciton blocking layer.

The organic layer includes two or more stacks including a hole transport layer, an emission layer, and an electron transport layer sequentially formed on the anode.

As another specific embodiment of the present invention, the present invention provides an electronic device including a display device including an organic light-emitting diode containing the compound represented by Formula 1 and a control unit for driving the display device.

In an embodiment of the present invention, the compound of Formula 1 may be included alone, the compound may be included in a combination of two or more different from each other, or the compound may be included in a combination of two or more with another compound.

Hereinafter, examples for synthesizing the compound represented by Formula 1 according to the present invention and examples for preparing an organic light-emitting diode will be described in detail, but the present invention is not limited to the following examples.

< Synthesis example >

The compound represented by Formula 1 according to the present invention may be synthesized according to the following synthesis examples, but is not limited thereto.

Synthesis example 1: Synthesis of compound (P-1)

Synthesis of Intermediate 1-1

After dissolving 2.30 g (94.5 mmol) of sodium hydride using 200 ml of dimethylacetamide, 10.0 g (59.1 mmol) of diphenylamine was added, followed by stirring at 0°C for 30 minutes. Then, 10.0 g (70.9 mmol) of 4-fluoronitrobenzene was slowly added and stirred at 100 degrees Celsius for 1 hour. After cooling the reaction solution, 40 ml of a cold 3 M hydrochloric acid solution was added and filtered to obtain a precipitate, and then recrystallized using isopropyl alcohol and distilled water to obtain 16.5 g (96% yield) of an orange solid, Intermediate 1-1.

Intermediate 1-1: mass spectrometry (FD+) m/z 290.11

Intermediate 1-2 synthesis

15.0 g (51.7 mmol) of Intermediate 1-1 and 0.66 g (6.20 mmol) of palladium/carbon were dissolved in 300 ml of ethanol and stirred under reflux for 1 hour. After slowly adding hydrazine monohydrate 15.5 g (310.0 mmol), the mixture was stirred under reflux for 12 hours. The solution was filtered under reflux using Silite, and 11.6 g (82.8% yield) of white solid Intermediate 1-2 was obtained through recrystallization using ethanol.

Intermediate 1-2: mass spectrometry (FD+) m/z 260.13

Synthesis of Intermediate 2-1

Dissolve 25.0 g (113.9 mmol) of 3-bromobenzoyl chloride using 300 ml of N-methyl-2-pyrrolidone. After that, 2.85 g (56.9 mmol) of hydrazine monohydrate was slowly added and stirred for 3 hours. After the reaction, a large amount of distilled water was added and obtained by filtering, and then 21.7 g (95.7% yield) of white solid intermediate 2-1 was obtained through recrystallization using dimethyl sulfoxide and distilled water.

Intermediate 2-1: mass spectrometry (FD+) m/z 397.91

Synthesis of Intermediate 2-2

20.0 g (50.2 mmol) of Intermediate 1 and 31.4 g (150.7 mmol) of phosphorus pentachloride were dissolved in 400 ml of toluene and stirred under reflux for 5 hours. After the reaction, toluene was removed using a rotary vacuum concentrator, the solid residue was washed three times with distilled water, and recrystallized with ethanol and dichloromethane to obtain 12.6 g (57.7% yield) of white solid Intermediate 2-2. .

Intermediate 2-2: mass spectrometry (FD+) m/z 433.84

Synthesis of Intermediate 3

10.0 g (22.9 mmol) of Intermediate 2-2 and 5.98 g (22.9 mmol) of Intermediate 1-2 were dissolved in 100 ml of N,N-dimethylaniline, followed by stirring at 135°C for 12 hours. After the reaction, 40 ml of 3 M hydrochloric acid solution was added, stirred for 30 minutes, filtered to obtain a precipitate, and purified by column chromatography with an ethyl acetate/hexane mixed solution to obtain 10.4 g (72.7% yield) of white solid Intermediate 3 .

Intermediate 3: Mass spectrometry (FD+) m/z 622.02

(P-1) synthesis

2.50 g (4.02 mmol) of Intermediate 3, 0.2 g (4.02 mmol) of sodium cyanide, and 0.01 g (0.24 mmol) of calcium hydride were dissolved using 30 ml of acetonitrile, followed by stirring at 70°C for 2 hours. The reaction solution was diluted with 50 ml of dichloromethane, filtered, and purified by column chromatography with a dichloromethane/hexane mixed solution, and finally 1.6 g of a pure white solid was obtained through sublimation purification.

Compound (P-1): yield 77.4%, mass spectrometry (FD+) m/z 514.19,

¹ H NMR (400 MHz, CDCl ₃ ): δ 8.56 (d, 2H), 7.88 (d, 2H), 7.73 ~ 7.69 (m, 4H), 7.37 (d, 2H), 7.20 (t, 4H), 6.81 (t, 2H), 6.63 (d, 6H)

Synthesis example 2: Synthesis of compound (P-2)

Synthesis of Intermediate 4-1

Dissolve 25.0 g (113.9 mmol) of 4-bromobenzoyl chloride using 300 ml of N-methyl-2-pyrrolidone. After that, 2.85 g (56.9 mmol) of hydrazine monohydrate was slowly added and stirred for 3 hours. After the reaction, a large amount of distilled water was added and filtered, and then 22.1 g (97.5% yield) of white solid intermediate 4-1 was obtained by recrystallization using dimethyl sulfoxide and distilled water.

Intermediate 4-1: mass spectrometry (FD+) m/z 397.91

Synthesis of Intermediate 4-2

20.0 g (50.2 mmol) of Intermediate 1 and 31.4 g (150.7 mmol) of phosphorus pentachloride were dissolved in 400 ml of toluene and stirred under reflux for 5 hours. After the reaction, toluene was removed using a rotary vacuum condenser, the solid residue was washed three times with distilled water, and recrystallized with ethanol and dichloromethane to obtain 14.3 g (65.4% yield) of white solid, Intermediate 4-2. .

Intermediate 4-2: mass spectrometry (FD+) m/z 433.84

Synthesis of Intermediate 5

10.0 g (22.9 mmol) of Intermediate 4-2 and 5.98 g (22.9 mmol) of Intermediate 1-2 were dissolved in 100 ml of N,N-dimethylaniline, followed by stirring at 135°C for 12 hours. After the reaction, 40 ml of 3 M hydrochloric acid solution was added, stirred for 30 minutes, filtered to obtain a precipitate, and purified by column chromatography with an ethyl acetate/hexane mixed solution to obtain 10.2 g (71.5% yield) of white solid Intermediate 3 .

Intermediate 5: Mass spectrometry (FD+) m/z 622.02

(P-2) synthesis

2.50 g (4.02 mmol) of Intermediate 5, 0.2 g (4.02 mmol) of sodium cyanide, and 0.01 g (0.24 mmol) of calcium hydride were dissolved using 30 ml of acetonitrile, followed by stirring at 70°C for 2 hours. The reaction solution was diluted with 50 ml of dichloromethane, filtered, and purified by column chromatography with a dichloromethane/hexane mixed solution, and finally 1.3 g of a pure white solid was obtained through sublimation purification.

Compound (P-2): yield 62.9%, mass spectrometry (FD+) m/z 514.19,

¹ H NMR (400 MHz, CDCl ₃ ): δ 7.97 (d, 4H), 7.82 (d, 4H), 7.37 (d, 2H), 7.2 (t, 4H), 6.81 (t, 2H), 6.63 (d , 6H)

Of organic light emitting diodes Manufacturing evaluation

( Example One) Delayed fluorescence Organic light emitting diode Produce

(ITO/PEDOT:PSS/TAPC/mCP/DPEPO: Compound 1/TSPO1/TPBi/LiF/Al)

The glass substrate on which the anode ITO was deposited was washed with ultrasonic waves for 30 minutes using tertiary distilled water and isopropyl alcohol.

After treating the surface of the cleaned ITO substrate using short-wavelength ultraviolet rays, PEDOT:PSS poly(3,4-edylenedioxythiophene):poly(styrenesulfonate) was spin coated to a thickness of 60 nm to An injection layer was formed.

Then, TAPC (1,1-bis[4-[N,N'-di(p-tolyl)amino]phenyl]cyclohexane) was deposited at a rate of 0.1 nm/s at a pressure of 1x10 ^-6 torr. A 20 nm hole transport layer was formed.

Thereafter, mCP (N,N-dicarbazolyl-3,5-benzene) was deposited at a rate of 0.1 nm/s at a pressure of 1×10 ⁻⁶ torr to form an exciton blocking layer of 10 nm.

Thereafter, at a pressure of 1x10 ^-6 torr, DPEPO as a host material was vacuum-deposited at a rate of 0.1 nm/s and a delayed fluorescent dopant material, Compound P-1 synthesized through Synthesis Example 1, at a rate of 0.02 nm/s A light emitting layer doped with 20% dopant was formed on the host.

TSPO1 (diphenylphosphine oxide-4-(triphenylsilyl)phenyl) and TPBi(1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene) were added to 0.1 at a pressure of 1x10 ^-6 torr By sequential deposition at a rate of nm/s, an exciton blocking layer and an electron transport layer of 5 nm and 30 nm were formed, respectively.

Thereafter, LiF as an electron injection material was deposited at a rate of 0.01 nm/s at a pressure of ¹ ×10 ⁻⁶ torr to form an electron injection layer of 1 nm.

Thereafter, Al was deposited at a rate of 0.5 nm/sec under a pressure of ¹ ×10 ⁻⁶ torr to form a 100 nm cathode, thereby forming an organic light emitting diode.

After the device was formed, the device was sealed using a CaO absorbent and a glass cover glass.

(Example 2)

An organic electroluminescent device was manufactured in the same manner as in Example 1, except that the compound of the present invention (P-2) shown in Table 1 was used instead of the compound (P-1) of the present invention in Example 1 I did.

( Comparative example One)

An organic light-emitting diode was manufactured in the same manner as in Example 1, except that Comparative Compound 1 below was used instead of Compound (P-1) of the present invention in Example 1.

<Comparative compound 1>

The electroluminescence characteristics were measured by applying a forward bias DC voltage to the organic electroluminescent devices manufactured according to Examples 1 to 2 and Comparative Example 1, and the evaluation results of the manufactured devices are shown in Table 2 below.

Emitting layer
(Dopant) Driving voltage
(V) EQE _max
(%) Luminance
(cd/m ² ) Current density
(mA/cm ² ) Color coordinates
(x,y) Comparative Example 1 T1 9.6 3.9 1005 9.8 0.15, 0.21 Example 1 P-1 5.64 14.6 1000 1.26 0.14, 0.15 Example 2 P-2 5.75 10.9 1002 1.41 0.14, 0.15

As can be seen from the results of Table 1, when an organic light-emitting diode was manufactured using the compound of the present invention, compared to the case of using the comparative compound 1, the driving voltage of the organic light-emitting diode could be lowered and the efficiency was significantly improved. .

In addition, in the evaluation results of the device fabrication described above, the device characteristics in which the compound of the present invention is applied only to the light emitting layer were described, but the compound of the present invention may be applied to one or more of the light emitting layer and the exciton blocking layer.

The above description is merely illustrative of the present invention, and those of ordinary skill in the art to improve the performance by including other compounds in the light emitting layer within the range not departing from the essential characteristics of the present invention Etc. There will be various variations.

Accordingly, the embodiments disclosed in the present specification are not intended to limit the present invention, but to describe the present invention, and the scope of the spirit of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technologies within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

10: anode 20: hole conducting layer
23: hole injection layer 25: hole transport layer
40: light emitting layer 50: electron conductive layer
53: electron injection layer 55: electron transport layer
70: cathode

Claims (7)

Compound represented by the following formula (1):
<Formula 1>

In Formula 1, each symbol may be defined as follows.
Ar ¹ is independently a single bond or a substituted or unsubstituted aryl group; A substituted or unsubstituted heteroaryl group; An alkyl group or aryl group in which the heterocyclic compound is substituted; Substituted or unsubstituted carbazole, fluorene, dibenzofuran or dibenzothiophene; Carbazole, fluorene, dibenzofuran or dibenzothiophene is a substituted alkyl group or aryl group,
Ar ^{2 to 3} are each independently halogen; Cyano group; An isocyanate group; Nitro group; Carbonyl group; Sulfoxide group; Sulfone group; Phosphite group; Phosphate group; Phosphine oxide group; A halogen element and a cyano group, an isocyanate group, a nitro group, a carbonyl group, a sulfoxide group, a sulfone group, a phosphite group, a phosphide group, or an alkyl group substituted with a phosphine oxide group, or a substituted or unsubstituted aryl group; A substituted or unsubstituted heteroaryl group; An alkyl group or aryl group in which the heterocyclic compound is substituted; Substituted or unsubstituted carbazole, fluorene, dibenzofuran or dibenzothiophene; Carbazole, fluorene, dibenzofuran or dibenzothiophene substituted alkyl or aryl group; is selected from the group consisting of,
Ar ^{4 to 5} are each independently alkoxy; Aryloxy; Aryl group; Alkylaryl group; Or an alkyl or aryl group substituted with an alkoxy group, an aryloxy group, an aryl group or an alkylaryl group; Alternatively, groups adjacent to each other may form a ring. The compound of claim 1, wherein the compound represented by Formula 1 is one of the following compounds:

Anode; Cathode; And an organic layer formed between the anode and the cathode,
The organic layer is an organic light-emitting diode comprising a compound represented by Formula 1 of claim 1 alone or in combination. The method of claim 3,
The organic layer is an organic light-emitting diode comprising at least one of a hole injection layer, a hole transport layer, an exciton blocking layer, a light emitting layer, an electron transport auxiliary layer, an electron transport layer and an electron injection layer. The method of claim 3,
The organic layer is an organic light-emitting diode comprising at least one of the emission layer and the exciton blocking layer. The method of claim 3,
The organic layer is an organic light-emitting diode comprising at least two stacks including a hole transport layer, an emission layer, and an electron transport layer sequentially formed on the anode. A display device comprising the organic light emitting diode of claim 3; And a control unit for driving the display device.

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